JP5803050B2 - Surface roughness measuring device, measurement waiting time setting method thereof, and measurement waiting time setting program - Google Patents

Description

  The present invention relates to a technique for optimizing a measurement waiting time in a surface roughness measuring apparatus.

  A surface roughness measuring device for measuring the surface roughness of a measured object scans the surface of the measured object with a stylus provided at the tip of a pickup and measures the displacement thereof, thereby measuring the surface roughness of the measured object. The thickness is measured (for example, Patent Documents 1 and 2).

  By the way, the scanning with the stylus is performed by moving the pickup by the driving means.

  The pickup drive means generally uses a motor as a drive source, converts the rotation of the motor into a linear motion, and reciprocates the pickup. The movement direction conversion and power transmission are generally performed using a gear or a feed screw.

  However, when a gear or a feed screw is used to drive the pickup, there is a problem that the measured value at the initial stage of scanning is not stable due to the presence of backlash. Further, since the speed of the start-up of the motor is unstable, there is a problem that the measurement tends to be unstable at the initial stage of scanning.

  For this reason, in actual measurement, a fixed waiting time (measurement waiting time) is set, and measurement is started after the waiting time elapses from the start of scanning. That is, the measurement (capture of displacement data) is started after a certain distance of air transport.

  As another method, a scale is incorporated in the apparatus and measurement is performed at intervals indicated by the scale (so-called scale sampling).

JP 10-104025 A JP-A-10-104027

  Conventionally, the measurement waiting time has been set with a large margin in order to ensure reliable measurement. As a result, there is a problem that the air transport distance becomes unnecessarily large. Such an air transport distance does not cause much problem when the measurement range is wide, but there is a problem that effective measurement cannot be performed when the measurement range is narrow as in the case of measuring a minute range.

  By incorporating the scale into the apparatus, problems such as backlash can be solved. However, when the scale is incorporated into the apparatus, there is a problem that the apparatus becomes complicated and large.

  The present invention has been made in view of such circumstances, and can reduce the measurement start time, and can measure a surface roughness measuring device capable of measuring a portion having a narrow measurement range, a measurement waiting time setting method thereof, and An object is to provide a measurement waiting time setting program.

  Means for solving the problems are as follows.

  [1] In the first aspect of the measurement waiting time setting method of the surface roughness measuring apparatus, a stylus provided in a pickup is brought into contact with an object to be measured, and the pickup is predetermined in a predetermined measurement direction by a driving unit. While a predetermined measurement waiting time has elapsed from the start of movement of the pickup, the displacement of the stylus is measured at a predetermined measurement cycle by the measuring means, and the surface roughness of the object to be measured is measured. In the measurement waiting time setting method of the surface roughness measuring apparatus, the stylus is brought into contact with a predetermined test piece, and the pickup is moved at the moving speed in the measurement direction. Measuring the displacement of the needle at the measurement period, analyzing the measurement result of the displacement, detecting a point at which the measured value starts to stabilize as a measured value stabilization start point, A step of calculating a movement time of the pickup required to reach the measured value stabilization start point from an up movement start, and a step of setting the calculated movement time as the measurement waiting time. And

  According to this aspect, the measurement waiting time is set as follows. First, the stylus provided on the pickup is brought into contact with a predetermined test piece, and a predetermined moving speed (the pickup at the time of actual measurement) in a predetermined measurement direction (the same direction as the movement direction of the pickup at the time of actual measurement). Move at the same speed). Then, the displacement of the stylus is measured at a predetermined measurement cycle (measurement cycle and cycle during actual measurement) immediately after the pickup starts moving. Next, the measurement result (measurement data) of the displacement obtained by the measurement is analyzed, and the point where the measurement value begins to stabilize is detected. Then, this point is set as a measured value stabilization start point. Next, the movement time of the pickup that is required immediately after the movement of the pickup is started until it reaches the measurement value stabilization start point is calculated. This time is calculated from the displacement measurement period. Then, the calculated travel time is set as the measurement waiting time. By setting the measurement waiting time in this manner, the measurement waiting time can be optimized and measurement can be started quickly. Further, the air transport distance can be minimized, and effective measurement can be performed even when the measurement range is narrow. When a plurality of pickup moving speeds (scanning speeds) can be selected, a measurement waiting time is set for each selectable moving speed. As a result, even when any moving speed is selected, measurement can be performed with the shortest measurement waiting time.

  [2] A second aspect of the measurement waiting time setting method of the surface roughness measuring apparatus is the measurement waiting time setting method of the surface roughness measuring apparatus of the first aspect before the pickup is moved in the measurement direction. The method further includes the step of moving the pickup by a predetermined amount in the direction opposite to the measurement direction.

  According to this aspect, when measuring the displacement by scanning the test piece with the stylus, first, the pickup is moved by a predetermined amount in the direction opposite to the measurement direction, and then moved in the measurement direction to measure the displacement. To implement. Thereby, for example, even when the pickup is driven by a gear or the like, the measurement waiting time can be set more appropriately. That is, by starting the measurement in this way, the measurement can be started with the backlash being maximized, and the measurement waiting time can be set more appropriately.

  [3] A third aspect of the measurement waiting time setting method of the surface roughness measuring apparatus is the measurement waiting time setting method of the surface roughness measuring apparatus of the first or second aspect, wherein the test piece has a surface on the surface. The predetermined unevenness is repeatedly formed at a constant pitch, and in the step of detecting the measurement value stabilization start point, the extreme value point of the measurement value that appears corresponding to the unevenness of the test piece is detected, and the adjacent extreme value point is detected. The distance between the two is calculated, the first extreme point where the calculated distance satisfies a preset criterion is detected, and the extreme point is set as a measured value stabilization start point.

  According to this aspect, the measurement value stabilization start point is detected as follows. First, as a premise, displacement is measured using a test piece in which predetermined irregularities are repeatedly formed on the surface at a constant pitch. Next, extreme points of the measured values appearing corresponding to the unevenness of the test piece are detected from the data obtained by the measurement. Next, the distance between adjacent extreme points is calculated for the detected extreme points. Next, the first extreme point where the calculated distance satisfies a preset criterion is detected. Then, the detected extreme point is set as a measured value stabilization start point. In other words, if the unevenness interval is accurately detected, it can be considered that the driving is stable, so that the distance between the extreme points detected corresponding to the unevenness interval first satisfies a certain standard. The extreme point is detected, and this is used as the starting point for measurement stability. The criterion for determination is, for example, about ± 5% of the interval between adjacent irregularities formed on the test piece (the distance between the peaks).

  [4] A fourth aspect of the measurement waiting time setting method of the surface roughness measuring apparatus is the measurement waiting time setting method of the surface roughness measuring apparatus of the third aspect. A sine wavefront having a predetermined waveform is formed.

  According to this aspect, a sine wavefront having a predetermined waveform as irregularities is formed on the surface of the test piece. Thereby, an accurate test piece can be easily prepared and measurement can be easily performed. In addition to this, the unevenness formed on the test piece may be, for example, a triangular shape or a rectangular shape.

  [5] A fifth aspect of the measurement waiting time setting method of the surface roughness measuring apparatus is the movement of the pickup in the measurement waiting time setting method of the surface roughness measuring apparatus according to any one of the first to fourth aspects. When a plurality of speeds can be selected, the pickup is moved at a reference moving speed, the measurement is performed, the measurement value stabilization start point is detected, the moving time is calculated, and the one moving speed is calculated. The measurement waiting time in the case of measuring at a moving speed is obtained, and the measurement waiting time in the case of measuring at another moving speed is obtained by calculating the coefficient set for each moving speed in advance with the one moving speed. By multiplying the time, the travel time is obtained for each travel speed, and the measurement waiting time when measuring at each travel speed is set.

  This mode is a special process when a plurality of pickup moving speeds (scanning speeds) can be selected. First, the pickup is moved at a reference moving speed, the measurement is performed, and the measurement waiting time is obtained. The obtained measurement waiting time can be applied only when scanning at one moving speed. In the case of scanning at other moving speeds, it is possible to set the measurement waiting time by performing the measurement in the same manner, but it takes time if performed individually. Therefore, for the measurement waiting time when measuring at another moving speed, the measuring waiting time is set by multiplying the moving time obtained at the one moving speed by the coefficient set for each moving speed in advance. Thereby, even when a plurality of pickup moving speeds can be selected, the measurement waiting time can be easily set for each moving speed. In addition, about a coefficient, many data are acquired and the relationship of the measurement waiting time for every moving speed is calculated | required and set, for example.

[6] In the first aspect of the surface roughness measuring apparatus, the stylus provided in the pickup is brought into contact with the object to be measured, and the pickup is moved at a predetermined moving speed in a predetermined measuring direction by the driving means. On the other hand, in a surface roughness measuring apparatus for measuring the surface roughness of the object to be measured by measuring the displacement of the stylus at a predetermined measurement cycle after a predetermined measurement waiting time from the start of movement of the pickup. An instruction means for instructing setting of the measurement waiting time, and the driving means is controlled in accordance with an instruction from the instruction means so that the stylus is brought into contact with a predetermined test piece and moved in the measurement direction. While moving at a speed, the measurement means is controlled to measure the displacement of the stylus at the measurement cycle from the start of movement of the pickup, and the displacement measurement performed in response to an instruction from the instruction means. Analyzes the results, the measured value stable starting point detecting means for measured value is detected as a measure stable starting point that begins to stabilize, the pickup required from the start of movement of the said pick-up until it reaches the measured value stable starting point a moving time calculation means for calculating the travel time, characterized in that the movement time calculated by said travel time calculation means includes a recording means for recording in the memory is set to the measurement waiting time.

  According to this aspect, the measurement waiting time is set as follows. First, the stylus provided on the pickup is brought into contact with a predetermined test piece, and a predetermined moving speed (the pickup at the time of actual measurement) in a predetermined measurement direction (the same direction as the movement direction of the pickup at the time of actual measurement). Move at the same speed). Then, immediately after the movement of the pickup is started, the displacement of the stylus is measured at a predetermined measurement period (the same period as the actual measurement period). Next, the measurement result (measurement data) of the displacement obtained by the measurement is analyzed, and the point where the measurement value begins to stabilize is detected. Then, this point is set as a measured value stabilization start point. Next, the movement time of the pickup that is required immediately after the movement of the pickup is started until it reaches the measurement value stabilization start point is calculated. This time is calculated from the displacement measurement period. Then, the calculated travel time is set as the measurement waiting time and recorded in the memory. At the time of actual measurement, information on the measurement waiting time recorded in this memory is read out and measurement is performed. That is, after the pickup movement starts, the measurement is started after the read measurement waiting time has elapsed. By setting the measurement waiting time as described above, the measurement waiting time can be optimized and measurement can be started quickly. In addition, the air transport distance can be minimized, and effective measurement can be performed even when the measurement range is narrow. When multiple pick-up movement speeds (scanning speeds) can be selected, a measurement waiting time is set for each selectable moving speed and is individually recorded in the memory (corresponding to each moving speed is associated with the measurement waiting time). Record.). As a result, measurement can be performed with the shortest measurement waiting time regardless of the movement speed selected.

  [7] A second aspect of the surface roughness measuring apparatus is the surface roughness measuring apparatus according to the first aspect, wherein the control means moves the pickup in the measuring direction before moving the pickup in the measuring direction. And a predetermined amount in the opposite direction.

  According to this aspect, when measuring the displacement by scanning the test piece with the stylus, first, the pickup is moved by a predetermined amount in the direction opposite to the measurement direction, and then moved in the measurement direction to measure the displacement. To implement. Thereby, for example, even when the pickup is driven by a gear or the like, the measurement waiting time can be set more appropriately. That is, by starting the measurement in this way, the measurement can be started with the backlash being maximized, and the measurement waiting time can be set more appropriately.

  [8] A third aspect of the surface roughness measuring apparatus is the surface roughness measuring apparatus according to the first or second aspect, wherein the test piece is repeatedly formed with predetermined irregularities on the surface at a constant pitch, The measurement value stabilization start point detecting means detects the extreme point of the measurement value that appears corresponding to the unevenness of the test piece, calculates the distance between adjacent extreme points, and the calculated distance is The first extreme point satisfying the set standard is detected, and the extreme point is set as a measurement value stabilization start point.

  According to this aspect, the measurement value stabilization start point is detected as follows. First, as a premise, displacement is measured using a test piece in which predetermined irregularities are repeatedly formed on the surface at a constant pitch. Next, extreme points of the measured values appearing corresponding to the unevenness of the test piece are detected from the data obtained by the measurement. Next, the distance between adjacent extreme points is calculated for the detected extreme points. Next, the first extreme point where the calculated distance satisfies a preset criterion is detected. Then, the detected extreme point is set as a measured value stabilization start point. In other words, if the unevenness interval is accurately detected, it can be considered that the driving is stable, so that the distance between the extreme points detected corresponding to the unevenness interval first satisfies a certain standard. The extreme point is detected, and this is used as the starting point for measurement stability. The criterion for determination is, for example, about ± 5% of the interval between adjacent irregularities formed on the test piece (the distance between the peaks).

  [9] A fourth aspect of the surface roughness measuring apparatus is the surface roughness measuring apparatus according to the third aspect, wherein a sine wave surface having a predetermined waveform as the irregularities is formed on the test piece. It is characterized by that.

  According to this aspect, a sine wavefront having a predetermined waveform as irregularities is formed on the surface of the test piece. Thereby, an accurate test piece can be easily prepared and measurement can be easily performed. In addition to this, the unevenness formed on the test piece may be, for example, a triangular shape or a rectangular shape.

[10] A fifth aspect of the surface roughness measuring device is a selectable movement in the surface roughness measuring device according to any one of the first to fourth aspects, wherein a plurality of movement speeds of the pickup can be selected. the set coefficients for each speed by multiplying the travel time calculated by the moving time calculating means, further comprising a second movement time calculating means for calculating a travel time of each mobile selectable speed, the recording means characterized in that the second movement time calculating means move time for each calculated selectable movement speed is set to the measurement waiting time for each selectable moving speed in recording in the memory.

  In this aspect, when a plurality of pickup moving speeds (scanning speeds) can be selected, the measurement waiting time can be set for each moving speed in one measurement. The measurement waiting time is set at one reference movement speed, and the measurement waiting time for other movement speeds is determined by multiplying the movement time obtained at one reference movement speed by a predetermined coefficient. To do. The measurement waiting time for each moving speed can be set in a short time. In addition, about a coefficient, many data are acquired and the relationship of the measurement waiting time for every moving speed is calculated | required and set, for example.

  [11] A measurement waiting time setting program of the surface roughness measuring apparatus causes a computer to realize the measurement waiting time setting method of the surface roughness measuring apparatus according to any one of the above 1 to 5. .

  According to this aspect, the measurement waiting time setting method according to any one of the above aspects 1 to 5 can be realized by a computer.

  According to the present invention, the measurement start time can be shortened, and a part having a narrow measurement range can be measured.

Front view showing the overall configuration of the surface roughness measuring device The perspective view which shows the whole structure of a surface roughness measuring apparatus Perspective view showing the configuration of the measurement unit Block diagram showing the electrical configuration of the data processing unit A perspective view showing a state during measurement of a measured object Perspective view showing the state during test piece measurement Graph showing an example of test piece measurement data Enlarged view showing another example of unevenness formed on the test piece

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[Device configuration]
1 and 2 are a front view and a perspective view, respectively, showing the overall configuration of a surface roughness measuring apparatus to which the present invention is applied.

  As shown in the figure, the surface roughness measuring apparatus 10 of the present embodiment is mainly composed of a measuring unit 12 and a data processing unit 14.

  The measurement unit 12 includes a pickup 16 that measures the surface roughness of the object to be measured, and a drive device 18 that moves the pickup 16.

  The pickup 16 is formed in a columnar shape as shown in FIG. A stylus 16 </ b> A is provided at the tip of the pickup 16. The pickup 16 detects the displacement of the stylus 16A with a built-in differential inductance (not shown) and outputs it as an electrical signal.

  As shown in FIG. 3, the driving device 18 includes a square cylindrical housing 20. A pickup mounting hole 22 having a shape corresponding to the outer peripheral shape of the pickup 16 is formed at the tip of the housing 20. The pickup 16 is mounted on the driving device 18 by inserting the rear end portion into the pickup mounting hole.

  Here, a connection portion (pin) (not shown) is provided at the rear end portion of the pickup 16. When the rear end portion of the pickup 16 is inserted into the pickup mounting hole 22 along the longitudinal direction of the housing 20, this connection portion is connected to a pickup connection portion (not shown) built in the housing 20. Accordingly, the pickup 16 is mounted on the driving device 18 and is electrically connected. The pickup 16 is mounted in parallel with the housing 20 of the driving device 18.

  The housing 20 of the driving device 18 is provided with a driving mechanism (not shown) for moving the pickup connecting portion. The drive mechanism includes a motor (not shown) as a drive source and a power transmission mechanism (not shown) that converts the rotation of the motor into a linear motion and transmits it to the pickup connecting portion. The power transmission mechanism includes, for example, a gear train and a feed screw mechanism.

  When the drive mechanism is driven, the pickup connecting portion reciprocates along the axial direction (longitudinal direction) of the housing 20. As a result, the pickup 16 connected to the pickup connecting portion reciprocates in the axial direction.

  The pickup 16 is provided so as to be able to reciprocate within a predetermined movable range. In other words, it reciprocates between a predetermined “origin position” and a predetermined “end position”.

  A connector 24 for electrically connecting to the data processing unit 14 is formed at the rear end of the housing 20 of the driving device 18. The drive device 18 is electrically connected to the data processing unit 14 by connecting a connection cable 26 to the connector 24.

  A pair of left and right adjustment base mounting grooves 28 </ b> A are formed on the outer periphery of the distal end portion of the housing 20. The adjustment base mounting groove 28 </ b> A is formed with a predetermined groove width and is formed orthogonal to the longitudinal direction of the housing 20.

  Similarly, a pair of left and right adjustment base mounting grooves 28 </ b> B are formed on the outer periphery of the rear end portion of the housing 20. The adjustment base mounting groove 28 </ b> B is formed with a predetermined groove width and is formed orthogonal to the longitudinal direction of the housing 20.

  As shown in FIG. 5, an adjustment base 70 is attached to the adjustment base attachment grooves 28A and 28B as needed.

  The adjustment base 70 includes a pair of rail portions 72, and is attached to the housing 20 of the driving device 18 by fitting the rail portions 72 into the adjustment base attachment grooves 28A and 28B. The pair of rail portions 72 are arranged to face each other, and are connected by a connecting portion 74 at the upper end portion thereof. The adjustment stand 70 is formed so that the rail portion 72 is self-supporting when installed on a horizontal plane.

  The adjustment base 70 attached to the housing 20 of the driving device 18 holds the housing 20 by the frictional force between the adjustment base attachment grooves 28 </ b> A and 28 </ b> B and the rail portion 72. The height and inclination of the drive device 18 can be adjusted by attaching the adjustment base 70 to the front and rear of the housing 20 and sliding the adjustment base 70 along the rail portion 72.

  The data processing unit 14 includes a flat square box-shaped data processing unit main body 30. The data processing unit main body 30 includes a connector 32 at an upper portion thereof, and a connection cable 26 is connected to the connector 32 so as to be electrically connected to the driving device 18.

  A front surface of the data processing unit main body 30 is provided with a display 34 for displaying various information, an operation panel 36 for performing various operations, and the like.

  Further, a power switch 38 and a connector unit 40 are provided on one side surface of the data processing unit main body 30.

  The connector unit 40 includes a communication connector 40A for connecting to an external device (for example, a personal computer) and a memory connector 40B for connecting to an external storage medium (storage, for example, a memory card or a USB memory). .

  The data processing unit 14 can transmit measurement data to an external device, for example, by connecting to the external device with a cable (not shown) using the communication connector 40A. Moreover, required data can be received from an external device. The communication connector 40A can be constituted by a USB connector, for example, and performs communication according to the USB standard. In addition to this, the communication connector 40A can also be configured by an IEEE connector or the like.

  In this example, a wired communication format is adopted, but a configuration in which a wireless communication unit is incorporated and wirelessly communicates with an external device may be employed.

  In addition, the data processing unit 14 can record the measured data, for example, in the external storage medium by connecting the external storage medium to the memory connector 40B. The memory connector 40B can be constituted by a USB connector, for example, and a USB memory can be used as an external storage medium.

  In this example, the memory connector 40B is configured by a USB connector, and the USB memory is used as an external storage medium. In addition to this, the memory connector 40B can also be constituted by slots of various memory cards, for example.

  Further, the upper surface of the data processing unit main body 30 is provided with a paper discharge port 42 through which the paper on which the measurement result is printed is discharged.

  FIG. 4 is a block diagram showing an electrical configuration of the data processing unit.

  As shown in the figure, the data processing unit 14 includes a microcomputer 50, a drive device control circuit 52, a signal conversion circuit 54, a display control circuit 56, a display 34, an operation panel 36, a communication control circuit 58A, a USB controller 58B, a print control. A circuit 60, a printer 62, a memory controller 64, an EEPROM 66, and the like are provided.

  The microcomputer 50 functions as a control unit that performs overall control of the entire surface roughness measuring apparatus 10 and also functions as an arithmetic processing unit that executes various arithmetic processes. The microcomputer 50 includes a CPU, a RAM, a ROM, and the like. The control program stored in the ROM is expanded on the RAM, and is sequentially executed by the CPU, thereby executing a predetermined process. In addition to the control program, the ROM stores various data necessary for the control.

  The drive device control circuit 52 controls the drive of the drive device 18 in accordance with a command from the microcomputer 50. That is, a drive signal is output to a drive mechanism (motor) built in the drive device 18. The drive mechanism of the drive device 18 operates according to the drive signal output from the drive device control circuit 52 to move the pickup 16.

  The signal conversion circuit 54 includes an A / D converter, converts the electrical signal output from the pickup 16 into a digital electrical signal, and outputs the digital electrical signal to the microcomputer 50. The microcomputer 50 processes the input signal according to a predetermined control program, and executes roughness detection processing and the like.

  The display control circuit 56 controls display on the display 34 in response to a command from the microcomputer 50.

  The operation panel 36 outputs the input operation information to the microcomputer 50. The microcomputer 50 executes various processes based on operation information input from the operation panel 36.

  The communication control circuit 58A transmits / receives data to / from an external device connected via the communication connector 40A in response to a command from the microcomputer 50.

  The USB controller 58B reads / writes data from / to an external device (USB memory in this example) connected via the memory connector 40B in response to a command from the microcomputer 50.

  The print control circuit 60 controls the drive of the printer 62 built in the data processing unit main body 30 in accordance with a command from the microcomputer 50 and executes print processing. As described above, the paper printed by the printer 62 is discharged from the paper discharge port 42 provided at the top of the data processing unit main body 30.

  The memory controller 64 reads / writes data from / to the EEPROM 66 in response to a command from the microcomputer 50. For example, various setting information set by the user is stored in the EEPROM 66. Although the EEPROM is used in this example, the configuration of the memory used here is not particularly limited as long as it is a so-called nonvolatile memory.

  The surface roughness measuring device 10 of the present embodiment is configured as described above.

[Measuring method]
Next, an outline of a method for measuring surface roughness using the surface roughness measuring apparatus 10 of the present embodiment will be described.

  First, measurement conditions are set. For example, the evaluation length, measurement speed (pickup moving speed), and the like are set. This setting is performed using the operation panel 36 of the data processing unit 14. The set information is displayed on the display 34.

  Next, the pickup 16 is set. That is, the stylus 16A provided at the tip of the pickup 16 is brought into contact with the surface of the object to be measured. At this time, as shown in FIG. 5, an adjustment base 70 is attached to the drive device 18 as necessary, and the inclination and height of the pickup 16 are adjusted.

  Next, the execution of measurement is instructed via the operation panel 36 of the data processing unit 14.

  When the execution of the measurement is instructed, the microcomputer 50 controls the driving of the driving device 18 via the driving device control circuit 52 and moves the pickup 16 in one direction at a constant moving speed (here, the pickup 16 is connected to the driving device 18). It is moved a certain distance in the direction of retracting to the housing 20 side. On the other hand, displacement data of the stylus 16A is acquired from the pickup 16.

  The displacement data of the stylus 16A is taken into the data processing unit 14 as an analog electric signal. The data processing unit 14 converts the electrical signal received from the pickup 16 into a digital electrical signal at a constant sampling period (measurement period) in the signal conversion circuit 54. The digital signal is signal-processed by the microcomputer 50 according to a predetermined control program, thereby measuring the surface roughness.

  The measurement result is output to the display 34. The measurement result is output as numerical data and displayed as a graph as necessary.

[Measurement wait time setting method]
As described above, the surface roughness is measured by detecting the displacement of the stylus when the pickup 16 is moved along the surface of the object to be measured.

  The pickup 16 is moved by being driven by the driving device 18, but the driving device 18 is not stable in the initial driving state due to the presence of backlash or the like. For this reason, initial measurement data becomes unstable.

  Therefore, in actual measurement, a fixed waiting time (measurement waiting time) is set, and displacement measurement data is taken in after a lapse of the waiting time from the start of driving.

  However, if this measurement waiting time is not set appropriately, the idle transport distance of the pickup 16 becomes long, and effective measurement cannot be performed.

  Therefore, in the surface roughness measuring apparatus 10 of the present embodiment, the measurement waiting time is appropriately set by setting the measurement waiting time by the following method.

  In setting the measurement waiting time, first, a predetermined test piece 80 is prepared. As shown in FIG. 6, the test piece 80 is formed in a rectangular plate shape, and a predetermined measurement region 82 is formed on the surface. In the measurement region 82, predetermined unevenness is repeatedly formed at a constant pitch. Here, a sine wavefront having a predetermined waveform (predetermined wave height and period) is formed. The irregularities are formed at a constant pitch along the longitudinal direction of the test piece 80, and the crest value and period are known.

  Using the test piece 80, the following measurement is performed.

  First, the pickup 16 is set. The setting is set so that the pickup 16 moves in a direction parallel to the surface of the test piece 80 and orthogonal to the wave of the wavefront formed in the measurement region 82. The stylus 16A is set to move (scan) over the measurement region 82. At this time, as shown in FIG. 6, an adjustment base 70 is attached to the drive device 18 as necessary to adjust the inclination and height of the pickup 16.

  Next, an instruction to set the measurement waiting time is given via the operation panel 36 of the data processing unit 14.

  When execution of the measurement waiting time setting is instructed, the microcomputer 50 executes measurement waiting time setting processing according to a predetermined control program.

  First, driving of the driving device 18 is controlled via the driving device control circuit 52, and the pickup 16 is moved in a certain direction (measurement direction) by a certain distance at a certain moving speed. Thereafter, the pickup 16 is moved by a constant distance in the other direction (the direction opposite to the measurement direction) at a constant movement speed. That is, once moved in the measurement direction, it is moved in the opposite direction to return to the original position (origin position). As a result, the backlash is maximized.

  As described above, the purpose of this process is to maximize the backlash, so the amount of movement of the pickup 16 is an amount that can maximize the backlash, and the minimum required value. It is preferable to set to. Thereby, it can prepare quickly.

  Next, the microcomputer 50 controls the driving of the driving device 18 via the driving device control circuit 52 and moves the pickup 16 in one direction (measurement direction) by a certain distance at a constant moving speed (moving speed at the time of measurement). . On the other hand, displacement data of the stylus 16A is acquired immediately after the pickup 16 is moved.

  The displacement data of the stylus 16A is taken into the data processing unit 14 as an analog electric signal. The data processing unit 14 converts the electrical signal received from the pickup 16 into a digital electrical signal at a constant sampling period (measurement period) in the signal conversion circuit 54. The microcomputer 50 sets a measurement waiting time by analyzing the displacement data according to a predetermined program. The analysis is performed according to the following procedure.

  As described above, the measurement is performed using the test piece 80. The test piece 80 has a sine wavefront having a predetermined waveform. Therefore, a sine waveform corresponding to this sine wavefront should be detected by performing the above measurement.

  FIG. 7 is a graph of the measurement data of the test piece.

  First, the microcomputer 50 detects the extreme point of the measurement value that appears corresponding to the wave irregularities of the test piece 80. This extreme point is detected at the peak and valley of the wave. The extreme points on the mountain side are P1, P2,... And the extreme points on the valley side are V1, V2,.

  The method for detecting the extreme points of the peaks and the valleys from the measurement data of the displacement is a known technique, and thus the specific method thereof will not be described.

  Next, of the detected extreme points (P1, P2,..., V1, V2,...), The extreme points that are detected first are used for setting the measurement waiting time. Set to. That is, when the extreme point (P1, P2,...) On the peak side is first detected, the extreme value that uses the extreme point (P1, P2,...) On the peak side for setting the measurement waiting time. Set to point. Conversely, when the extreme points (V1, V2,...) On the valley side are first detected, the extreme points (V1, V2,...) That use the extreme points (V1, V2,...) On the valley side are set for the measurement waiting time. Set to the value point.

  The detection of extreme points is performed along the time series of measurement value input. Therefore, the extreme point detected first means the extreme point detected first from the start of measurement (in this measurement, the extreme point detected first from the start of movement of the pickup 16). On the mountain side, the extreme point P1 is the extreme point detected first, and on the valley side, the extreme point V1 is the extreme point detected first.

  In the example shown in FIG. 7, the extreme point P1 on the peak side is detected before the extreme point V1 on the valley side, so the extreme points P1, P2,. Extreme point used to set time.

  Next, the distance between adjacent extreme points is calculated for each extreme point (here, the extreme point on the peak portion side) used for setting the measurement waiting time. That is, the distance between P1-P2, P2-P3,..., P (n-1) -P (n) is calculated.

  Next, the calculated distance between each extreme point is evaluated. This evaluation is based on the distance between the calculated extreme points and the distance between the peak and peak of the sine wave formed on the test piece (= the distance between the valley and the valley) X This is done by comparing Specifically, it is performed by obtaining a percentage with respect to the distance X and determining whether or not the standard is satisfied. The standard is, for example, ± 5%. Therefore, if the distance X is within a range of 95% to 105%, it is determined that the standard is satisfied.

  Next, based on the evaluated result, the first extreme point that satisfies the criterion is detected. For example, when an interval between extreme points that first satisfies the criterion is P (n−1) −P (n), P (n−1) is the first extreme point that satisfies the criterion. Then, the pole point that first satisfies the standard is set as a measurement value stabilization start point. That is, if the distance between adjacent extreme points can be accurately detected, it can be considered that the drive is stable. Therefore, the extreme point that satisfies the standard is detected first, and that point is set as the measured value stabilization start point.

  Next, a time S required for the pickup 16 to reach the measurement value stabilization start point from the start of movement is calculated based on the obtained position of the measurement stability start point and the measurement value sampling period. Then, this time S (movement time from the start of measurement of the pickup 16) is set as a measurement waiting time.

  The setting of the measurement waiting time is completed in the series of steps. When the measurement waiting time is obtained, the microcomputer 50 records the obtained measurement waiting time information in the EEPROM 66.

  At the time of actual measurement, the measurement waiting time information recorded in the EEPROM 66 is read and measurement is performed. That is, the measurement data is taken in after the measurement waiting time has elapsed from the start of measurement (start of movement of the pickup 16).

  Thus, according to the surface roughness measuring apparatus 10 of this Embodiment, a measurement waiting time can be set appropriately. Thereby, the air transport distance can be minimized, and even when a minute range is measured, it can be measured effectively. Further, it is possible to perform measurement quickly with a minimum measurement waiting time.

[How to set the measurement wait time when multiple measurement speeds can be selected]
When the measurement speed (moving speed of the pickup 16) can be switched (when a plurality of pickup speeds can be selected), the above measurement waiting time setting operation is performed for each settable measurement speed. Thereby, the measurement waiting time can be set appropriately for each measurement speed. The set measurement wait time information is recorded in the EEPROM 66 for each measurement speed. At the time of actual measurement, the measurement waiting time information is read according to the set measurement speed, and the measurement is performed.

  However, in the case where a large number of measurement speeds can be selected, it takes time to set the measurement waiting time for each selectable speed. Therefore, when a plurality of measurement speeds can be selected, the measurement waiting time corresponding to each measurement speed can be set by the following method.

  First, the measurement waiting time (time required for the pickup 16 to reach the measurement value stabilization start point (movement time)) is obtained by the above procedure. The measurement speed for obtaining the measurement waiting time is a reference measurement speed, and one that can be selected during actual measurement is used. Therefore, for example, when the measurement speed can be selected in three stages (for example, A, B, C), one of them (for example, speed A) is selected, and the measurement waiting time is obtained by the above procedure.

  Next, the measurement waiting time (movement time) is multiplied by a predetermined coefficient to obtain the measurement waiting time for the other measurement speeds (speeds B and C).

  Here, the coefficient is prepared for each selectable measurement speed, and the measurement waiting time is calculated for each selectable measurement speed.

  This coefficient is set by performing measurement at each measurement speed that can be selected in advance, calculating a measurement waiting time, and obtaining a relationship between the measurement speed serving as a reference and the measurement waiting time. Therefore, in order to set with high accuracy, it is preferable to obtain the relationship from a large number of measurement data. A known technique can be used for the statistical method of data.

  In this way, when multiple measurement speeds can be selected, the measurement waiting time is set by performing measurement with the test piece only for the reference measurement speed, and for other measurement speeds, the coefficients prepared in advance are set. It can also be obtained by multiplying.

  Thereby, even when a plurality of measurement speeds can be selected, the measurement waiting time can be easily set.

  The obtained measurement waiting time for each measurement speed is stored in the EEPROM 66 for each measurement speed as described above.

  In the above example, one of the measurement speeds that can be selected in actual measurement is used as the reference measurement speed. However, the reference measurement speed is not necessarily selectable at the actual measurement speed. There is no. That is, if a coefficient is obtained between the measurement waiting time obtained at the reference measurement speed, the reference measurement speed does not necessarily need to be a measurement speed that can be selected in actual measurement.

  In actual measurement, when the measurement speed can be adjusted steplessly, the measurement waiting time can be obtained by a function.

[Other embodiments]
Some surface roughness measuring devices allow various combinations of pickups and driving devices. In other words, some types of pickups and a plurality of types of drive devices are prepared and can be used in combination according to the application. In this case, a measurement waiting time is set for each driving device (if a measurement speed can be further selected, a measurement waiting time is further set for each measurement speed). The set measurement waiting time for each driving device is stored in the EEPROM of the data processing unit, and is read and used sequentially. In this case, it is preferable that the type of the connected drive device is automatically detected and the corresponding measurement waiting time is automatically read and set.

  In the above-described embodiment, when measuring the test piece 80, first, the pickup is moved by a certain distance in the measurement direction and then moved in the reverse direction to return to the origin position. Since the purpose is to maximize the backlash, this processing is not necessary if the backlash has already been maximized at the stage of measurement by the pickup 16. That is, this process is not necessary when the pickup 16 has already been moved in the direction opposite to the measurement direction.

  Furthermore, in the said embodiment, although the uneven | corrugated shape formed in the measurement area | region 82 of the test piece 80 is made into the sine wave shape, another shape can also be employ | adopted. For example, as shown in FIG. 8, a trapezoidal wave shape (FIG. (A)), a triangular wave shape (FIG. (B)), or a rectangular wave shape can be used. The shape of these irregularities is selected according to the size, shape, etc. of the stylus provided in the pickup to be used.

  Further, the program for setting the measurement waiting time can be provided by being stored in a predetermined recording medium.

  DESCRIPTION OF SYMBOLS 10 ... Surface roughness measuring apparatus, 12 ... Measuring part, 14 ... Data processing part, 16 ... Pickup, 16A ... Stylus, 18 ... Drive apparatus, 20 ... Housing, 22 ... Pickup mounting hole, 24 ... Connector, 26 ... Connection Cable, 28A, 28B ... Adjustment base mounting groove, 30 ... Data processing unit body, 32 ... Connector, 34 ... Display, 36 ... Operation panel, 38 ... Power switch, 40 ... Connector part, 40A ... Communication connector, 40B ... Memory connector , 42 ... discharge port, 50 ... microcomputer, 52 ... drive device control circuit, 54 ... signal conversion circuit, 56 ... display control circuit, 58A ... communication control circuit, 58B ... USB controller, 60 ... print control circuit, 62 ... printer 64 ... Memory controller 66 ... EEPROM 70 ... Adjustment stand 72 ... Rail part 74 ... Connecting part 80 ... Test piece 82 ... the measurement region

Claims (11)

A stylus provided on the pickup is brought into contact with the object to be measured, and the pickup is moved at a predetermined movement speed in a predetermined measurement direction by a driving means, while a predetermined measurement waiting time has elapsed since the start of the movement of the pickup. In the measurement waiting time setting method of the surface roughness measuring apparatus for measuring the displacement of the stylus by a measuring means at a predetermined measurement cycle and measuring the surface roughness of the object to be measured,
The stylus on the test piece in which a predetermined irregularity is formed repeatedly at a predetermined pitch on the surface by contact, while moving in the movement speed of the pickup to the measurement direction, from the movement start of the stylus of the pick-up Measuring the displacement at the measurement period;
Analyzing the measurement result of the displacement, and detecting a point where the measurement value starts to stabilize as a measurement value stabilization start point, and detecting an extreme point of the measurement value appearing corresponding to the unevenness of the test piece Calculating a distance between adjacent extreme points, detecting an extreme point where the calculated distance first satisfies a preset criterion, and setting the extreme point as a measured value stabilization start point; ,
Calculating the movement time of the pickup required to reach the measured value stabilization start point from the movement start of the pickup;
Setting the calculated travel time to the measurement waiting time;
A measurement waiting time setting method for a surface roughness measuring device. In the step of analyzing the measurement result of the displacement and detecting the point where the measurement value starts to stabilize as the measurement value stabilization start point, an extreme point on the peak side of the measurement value that appears corresponding to the unevenness of the test piece, Calculate the distance between adjacent extreme points at the extreme point where the extreme point is first detected among the extreme points on the valley side, and the calculated distance is based on a preset reference. 2. The measurement waiting time setting method for a surface roughness measuring apparatus according to claim 1, wherein an extreme value point that is initially satisfied is detected, and the extreme value point is used as a measurement value stabilization start point. The method for setting a measurement waiting time of a surface roughness measuring apparatus according to claim 1 or 2 , wherein a sine wavefront having a predetermined waveform as the irregularities is formed on the surface of the test piece. A stylus provided on the pickup is brought into contact with the object to be measured, and the pickup is moved at a predetermined movement speed in a predetermined measurement direction by a driving means, while a predetermined measurement waiting time has elapsed since the start of the movement of the pickup. A surface roughness measuring device for measuring the surface roughness of the object to be measured by measuring the displacement of the stylus at a predetermined measurement period by a measuring means, wherein the surface roughness can select a plurality of moving speeds of the pickup In the measurement waiting time setting method of the measuring device,
The stylus is brought into contact with a predetermined test piece, and the pickup is moved at a reference moving speed in the measurement direction, while the displacement of the stylus is measured at the measurement cycle from the start of movement of the pickup. And steps to
Analyzing the measurement result of the displacement, and detecting a point where the measurement value starts to stabilize as a measurement value stabilization start point;
Calculating the movement time of the pickup required to reach the measured value stabilization start point from the movement start of the pickup;
Setting the calculated travel time to the measurement waiting time when measuring at the one moving speed;
A step of setting the measurement waiting time when measuring at another moving speed, and multiplying the moving time obtained at the one moving speed by a coefficient set in advance for each moving speed, for each moving speed Obtaining a moving time and setting the measurement waiting time when measuring at each moving speed ; and
A measurement waiting time setting method for a surface roughness measuring device. The surface roughness according to any one of claims 1 to 4, further comprising a step of moving the pickup by a predetermined amount in a direction opposite to the measurement direction before moving the pickup in the measurement direction. Measurement waiting time setting method of the measuring device. A stylus provided on the pickup is brought into contact with the object to be measured, and the pickup is moved at a predetermined moving speed in a predetermined measuring direction by a driving unit, while a predetermined measurement waiting time has elapsed from the start of the movement of the pickup. In the surface roughness measuring device for measuring the displacement of the stylus by a measuring means at a predetermined measurement cycle and measuring the surface roughness of the object to be measured,
Instruction means for instructing the setting of the measurement waiting time;
In response to an instruction of said instruction means moving, controls the drive means, the stylus on the test piece in which a predetermined irregularity is formed repeatedly at a predetermined pitch on the surface by contact, by the moving speed to the measuring direction Control means for controlling the measurement means, and measuring the displacement of the stylus at the measurement period from the start of movement of the pickup;
Wherein analyzing the measurement results of the displacement performed in accordance with an instruction instructing means, a measurement value stable starting point detecting means for measuring values is detected as a measure stable starting point that begins to stabilize, the test piece The extreme points of the measured values appearing corresponding to the unevenness of the above are detected, the distance between the adjacent extreme points is calculated, and the calculated extreme point is the first extreme point that satisfies a preset criterion. A measurement value stabilization start point detecting means for detecting and using the extreme value point as a measurement value stabilization start point;
A movement time calculating means for calculating a movement time of the pickup required from the start of movement of the pickup to the measurement value stabilization start point;
Recording means for setting the travel time calculated by the travel time calculation means to the measurement waiting time and recording it in a memory;
A surface roughness measuring device comprising: The measurement value stabilization start point detecting means detects an extreme point first among the extreme point on the peak side and the extreme point on the valley side of the measurement value that appears corresponding to the unevenness of the test piece. At the extreme point on the side, the distance between adjacent extreme points is calculated, the extreme point where the calculated distance first satisfies a preset criterion is detected, and the extreme value point is stabilized. The surface roughness measuring device according to claim 6, wherein the surface roughness measuring device is a starting point. The surface roughness measuring device according to claim 6 or 7 , wherein a sine wavefront having a predetermined waveform as the irregularities is formed on the surface of the test piece. A stylus provided on the pickup is brought into contact with the object to be measured, and the pickup is moved at a predetermined moving speed in a predetermined measuring direction by a driving unit, while a predetermined measurement waiting time has elapsed from the start of the movement of the pickup. A surface roughness measuring device for measuring the surface roughness of the object to be measured by measuring the displacement of the stylus at a predetermined measurement period by a measuring means, wherein the surface roughness can select a plurality of moving speeds of the pickup In the measuring device,
Instruction means for instructing the setting of the measurement waiting time;
In response to an instruction from the instruction means, the driving means is controlled so that the stylus is brought into contact with a predetermined test piece and moved at a reference moving speed in the measurement direction, while the measurement means is Control means for measuring the displacement of the stylus at the measurement cycle from the start of movement of the pickup;
A measurement value stabilization start point detection means for analyzing a measurement result of the displacement performed in response to an instruction from the instruction means and detecting a point where the measurement value starts to stabilize as a measurement value stabilization start point;
A movement time calculating means for calculating a movement time of the pickup required from the start of movement of the pickup to the measurement value stabilization start point;
A second movement time calculation means for calculating a movement time for each selectable movement speed by multiplying the movement time calculated by the movement time calculation means by a coefficient set for each selectable movement speed ;
A recording unit configured to set the measurement waiting time as the measurement waiting time and record the result in the memory, and for each selectable moving speed calculated by the second traveling time calculation unit; Recording means for setting the recording waiting time for each selectable moving speed and recording it in the memory ;
A surface roughness measuring device comprising: 10. The surface roughness according to claim 6, wherein the control unit moves the pickup by a predetermined amount in a direction opposite to the measurement direction before moving the pickup in the measurement direction. 11. Measuring device.   6. A measurement waiting time setting program for a surface roughness measuring apparatus, which causes a computer to implement the measurement waiting time setting method for a surface roughness measuring apparatus according to claim 1.

Images