JP5293686B2 - 3D shape measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely obtain a rotation angle of a mirror even if long time has passed since the starting of use, and to keep fixed measuring accuracy, in a three-dimensional shape measuring device scanning a laser beam by using an MEMS mirror. <P>SOLUTION: A first mirror 14 is provided, in which a mirror 14a rotatably supported and a driving circuit rotating the mirror 14a according to a supplied electric signal to displace that are integrally formed. The mirror 14a has a first reflecting surface and a second reflecting surface capable of respectively reflecting a laser beam. The laser beam for measuring a distance between the measuring device and a measuring object OB is irradiated on the first reflecting surface. The laser beam for detecting the rotation angle of the mirror 14a is irradiated on the second reflecting surface. A light receiving sensor 26 receiving reflecting light from the second reflecting surface is provided. A mirror angle detection circuit 42 calculating the rotation angle of the mirror 14a from a light receiving position of the reflecting light in the light receiving sensor 26 is provided. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention irradiates an object to be measured while scanning with laser light, receives scattered light, which is reflected light, by a light receiver, and relationship between the irradiation position or irradiation direction of the laser light and the light receiving position of the reflected light. The present invention relates to a three-dimensional shape measuring apparatus that measures a three-dimensional shape of a measurement object according to the principle of a triangulation method.

  Conventionally, for example, as shown in Patent Document 1 below, a measurement object is irradiated while scanning with laser light, the irradiation position or irradiation direction of the irradiated laser light, and reflected light (scattering) from the measurement object A three-dimensional shape measuring apparatus that measures the three-dimensional shape of a measurement object based on the principle of the triangulation method is known from the relationship with the light receiving position. In the three-dimensional shape measuring apparatus disclosed in Patent Document 1, in order to reduce the size of the three-dimensional shape measuring apparatus and reduce power consumption, a micro electro mechanical system mirror (hereinafter referred to as a micro electro mechanical system mirror) is used. The system mirror is called a MEMS mirror.)

JP 2008-286744 A

  When scanning a laser beam with a MEMS mirror to measure a three-dimensional shape, the rotational angle data of the MEMS mirror is acquired at substantially the same timing as the timing of acquiring the light receiving position data of the reflected light from the measurement object. Is used to calculate the three-dimensional coordinate data. The rotation angle of the MEMS mirror is determined by the intensity (for example, the magnitude of voltage, current, etc.) of the electric signal supplied to the MEMS mirror. Therefore, if the relationship between the intensity of the electrical signal supplied to the MEMS mirror and the rotation angle of the mirror is examined in advance and an electrical signal having an intensity corresponding to the target rotation angle is supplied, it is necessary to calculate the three-dimensional coordinate data. It is considered that rotation angle data of a simple MEMS mirror can be acquired. However, the MEMS mirror changes the relationship between the intensity of the electric signal to be supplied and the rotation angle of the mirror after a long period of time has elapsed since the start of use. The angle cannot be acquired, and the accuracy of the three-dimensional shape measurement cannot be maintained.

  The present invention has been made to cope with the above-described problem, and an object of the present invention is to provide a rotation angle of a mirror in a three-dimensional shape measuring apparatus that scans laser light using a MEMS mirror even if a long period of time has passed since the start of use. It is possible to accurately control the three-dimensional shape measurement. In the description of each constituent element of the present invention below, in order to facilitate understanding of the present invention, reference numerals of corresponding portions of the embodiments described later are shown in parentheses, but each constituent element of the present invention is described. Should not be construed as being limited to the configurations of the corresponding portions indicated by the reference numerals of the embodiments.

In order to achieve the above object, the present invention is characterized in that the laser light source (10) that emits laser light toward the measurement object (OB) and the emission direction of the laser light emitted from the laser light source are changed. Laser light emission direction changing means (14) for scanning the surface of the measurement object with laser light, and emission direction detection means (22, 22) for detecting the emission direction of the laser light to the measurement object by the laser light emission direction changing means. 24, 26), a first light receiving sensor (20) for receiving the scattered light reflected by the surface of the measurement object, and a first light receiving position detecting means for detecting the light receiving position of the scattered light in the first light receiving sensor ( 50) and the surface of the object to be measured based on the principle of triangulation using the emission direction of the laser light detected by the emission direction detection means and the light receiving position of the scattered light detected by the first light receiving sensor. In the three-dimensional shape measuring apparatus and a coordinate data calculating means (52) for calculating a three-dimensional coordinate data representing the shape, the laser beam emitting direction changing means is perpendicular to the optical axis of the laser beam emitted from the laser light source A mirror part (14a) having a first reflection surface that is supported rotatably around a rotation axis and reflects the laser beam, and a second reflection surface that reflects a light beam different from the laser beam, and an electric signal supplied And a mirror (14) integrally formed with a driving device (14b) for rotating and displacing the mirror portion around the rotation axis according to the direction, and the emission direction detecting means is directed toward the second reflecting surface of the mirror. A light beam emitting means (22) for emitting the light beam, and a second light receiving sensor ( 26A ) for receiving the reflected light of the light beam from the second reflecting surface , each corresponding to the amount of received light The A plurality of light receiving elements (26A1, 26A2,..., 26A9) that output a light reception signal with high intensity are arranged in a line, and reflected light from the second reflecting surface is any one of the plurality of light receiving elements. A second light receiving sensor for receiving light by two light receiving elements, and a mirror rotation angle detecting means ( 42A ) for detecting a rotation angle of the mirror unit based on a light receiving position of the reflected light in the second light receiving sensor , A plurality of amplifiers (42c1, 42c2,..., 42c9) provided corresponding to the light receiving elements, respectively, for amplifying the received light signals output from the plurality of light receiving elements and converting them to different signal levels. And an adder (42d) for outputting an addition signal obtained by adding the light reception signals converted by a plurality of amplifiers, and using the value of the addition signal as light reception data at a constant time interval. The light receiving element stored in the storage means (42f1) to be stored and the light receiving element receiving the reflected light from the second reflecting surface is specified from the value of the light receiving data stored in the storage means, and the light receiving used for specifying the light receiving element. The received light data having the same value as the data, and the number of received light data continuously stored before and after storing the received light data used to identify the light receiving element is used to determine whether the second light receiving sensor has received the data from the second reflecting surface. There is provided a mirror rotation angle detection means having an angle calculation means (42f) for calculating the light reception position of the reflected light and calculating the rotation angle of the mirror unit based on the calculated light reception position .

  According to the three-dimensional shape measuring apparatus configured as described above, the rotation angle of the mirror unit is calculated based on the light receiving position of the reflected light from the second reflection surface by irradiating the second reflection surface of the mirror unit with light. Therefore, even if the relationship between the strength of the electric signal supplied to the driving device and the rotation angle of the mirror changes after a long period of time has elapsed since the start of use, the accuracy of the rotation angle to be acquired does not change and is three-dimensional. The accuracy of shape measurement can be maintained.

Further, the present invention is characterized in that the laser light source (10) that emits laser light toward the measurement object (OB) and the emission direction of the laser light emitted from the laser light source are changed to change the surface of the measurement object. Laser beam emission direction changing means (14) for scanning the laser beam, emission direction detection means (22, 24, 26) for detecting the emission direction of the laser beam to the measurement object by the laser beam emission direction changing means, A first light receiving sensor (20) for receiving scattered light reflected by the surface of the measurement object, first light receiving position detecting means (50) for detecting a light receiving position of the scattered light in the first light receiving sensor, and an emission direction A three-dimensional representation of the shape of the surface of the object to be measured based on the principle of triangulation using the emission direction of the laser light detected by the detection means and the light receiving position of the scattered light detected by the first light receiving sensor. seat In the three-dimensional shape measuring apparatus provided with coordinate data calculation means (52) for calculating data, the laser light emission direction changing means is rotatable about a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source. And a mirror part (14a) having a first reflection surface that reflects the laser light and a second reflection surface that reflects a light beam different from the laser light, and a mirror part according to the supplied electrical signal. A mirror (14) integrally formed with a driving device (14b) that rotates and rotates around the rotation axis is provided, and the emission direction detection means includes a light source (22) and light emitted from the light source. A light beam emitting means for emitting the line light toward the second reflecting surface of the mirror, and reflection of the line light from the second reflecting surface. Second to receive light An optical sensor (26B), which is formed by arranging two sensors (26B1, 26B2) that output a received light signal having an intensity corresponding to the amount of received light, and reflects the line light reflected by the second reflecting surface. A second light receiving sensor for receiving light by the two sensors, and a mirror rotation angle detecting means having an angle calculating means (42i) for calculating a rotation angle of the mirror section using a difference in intensity of signals output from the two sensors. It is in having. According to this, the difference in the intensity of the signals output from the two sensors corresponds to the rotation angle of the mirror, and there is no need to calculate the light receiving position of the reflected light from the second reflecting surface in the second light receiving sensor. Therefore, the rotation angle of the mirror part can be calculated at high speed.

Further, the present invention is characterized in that the laser light source (10) that emits laser light toward the measurement object (OB) and the emission direction of the laser light emitted from the laser light source are changed to change the surface of the measurement object. Laser beam emission direction changing means (14) for scanning the laser beam, emission direction detection means (22, 24, 26) for detecting the emission direction of the laser beam to the measurement object by the laser beam emission direction changing means, A first light receiving sensor (20) for receiving scattered light reflected by the surface of the measurement object, first light receiving position detecting means (50) for detecting a light receiving position of the scattered light in the first light receiving sensor, and an emission direction A three-dimensional representation of the shape of the surface of the object to be measured based on the principle of triangulation using the emission direction of the laser light detected by the detection means and the light receiving position of the scattered light detected by the first light receiving sensor. seat In the three-dimensional shape measuring apparatus provided with coordinate data calculation means (52) for calculating data, the laser light emission direction changing means is rotatable about a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source. And a mirror part (14a) having a first reflection surface that reflects the laser light and a second reflection surface that reflects a light beam different from the laser light, and a mirror part according to the supplied electrical signal. A mirror (14) integrally formed with a driving device (14b) that rotates and rotates around the rotation axis is provided, and the emission direction detection means emits the light beam toward the second reflecting surface of the mirror. A light beam emitting means (22) for receiving, a second light receiving sensor (26, 26A, 26B) for receiving the reflected light of the light beam from the second reflecting surface, and a light receiving position of the reflected light in the second light receiving sensor. And a mirror rotation angle detection means (42, 42A, 42B) for detecting the rotation angle of the mirror section, wherein the first light receiving position detection means is the rotation angle of the mirror section detected by the mirror rotation angle detection means. Is to detect the light receiving position of the scattered light in the first light receiving sensor. In this case, the second light receiving sensor (26) is formed by arranging a plurality of light receiving elements that output a light receiving signal having an intensity corresponding to the amount of received light in a line, and reflects reflected light from the second reflecting surface. Light is received by two or more adjacent light receiving elements among the plurality of light receiving elements, and the mirror rotation angle detecting means (42) specifies the light receiving element having the largest received light amount among the plurality of light receiving elements, An angle calculating means (42b) for calculating the rotation angle of the mirror unit based on the position of the light receiving element in the second light receiving sensor may be provided. According to this, the coordinate data calculation means can calculate the coordinate data when the rotation angle of the mirror portion becomes a preset angle. Therefore, the measurement accuracy can be changed depending on the measurement range of the measurement object. That is, in the range where the change in shape is large and the measurement accuracy is desired to be high, the interval between the predetermined angles is set finely. Conversely, in the range where the measurement accuracy may be low without much change in shape, the predetermined angle is set. The interval of the angle should be set coarsely. Thereby, since the data amount of measurement data can be suppressed to the minimum necessary, coordinate data can be calculated at high speed compared with the case where the entire measurement range is measured with high accuracy.

Further, the present invention is characterized in that the laser light source (10) that emits laser light toward the measurement object (OB) and the emission direction of the laser light emitted from the laser light source are changed to change the surface of the measurement object. Laser beam emission direction changing means (14) for scanning the laser beam, emission direction detection means (22, 24, 26) for detecting the emission direction of the laser beam to the measurement object by the laser beam emission direction changing means, A first light receiving sensor (20) for receiving scattered light reflected by the surface of the measurement object, first light receiving position detecting means (50) for detecting a light receiving position of the scattered light in the first light receiving sensor, and an emission direction A three-dimensional representation of the shape of the surface of the object to be measured based on the principle of triangulation using the emission direction of the laser light detected by the detection means and the light receiving position of the scattered light detected by the first light receiving sensor. seat In the three-dimensional shape measuring apparatus provided with coordinate data calculation means (52) for calculating data, the laser light emission direction changing means is rotatable about a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source. And a mirror part (14a) having a first reflection surface that reflects the laser light and a second reflection surface that reflects a light beam different from the laser light, and a mirror part according to the supplied electrical signal. A mirror (14) integrally formed with a driving device (14b) that rotates and rotates around the rotation axis is provided, and the emission direction detection means emits the light beam toward the second reflecting surface of the mirror. A light beam emitting means (22) for receiving, a second light receiving sensor (26, 26A, 26B) for receiving the reflected light of the light beam from the second reflecting surface, and a light receiving position of the reflected light in the second light receiving sensor. And a mirror rotation angle detection means (42, 42A, 42B) for detecting the rotation angle of the mirror section. The laser beam emission direction changing means is driven by the rotation angle of the mirror section detected by the mirror rotation angle detection means. The apparatus further comprises an electric signal changing means (40b, 40c) for changing the electric signal so as to have a predetermined rotation angle corresponding to the electric signal supplied to the apparatus, and the first light receiving position detecting means is arranged at a predetermined time interval. It is to detect the light receiving position of the scattered light in the first light receiving sensor. In this case, the second light receiving sensor (26) is formed by arranging a plurality of light receiving elements that output a light receiving signal having an intensity corresponding to the amount of received light in a line, and reflects reflected light from the second reflecting surface. Light is received by two or more adjacent light receiving elements among the plurality of light receiving elements, and the mirror rotation angle detecting means (42) specifies the light receiving element having the largest received light amount among the plurality of light receiving elements, An angle calculating means (42b) for calculating the rotation angle of the mirror unit based on the position of the light receiving element in the second light receiving sensor may be provided. According to this, the rotation angle of the mirror portion becomes a predetermined rotation angle corresponding to the electric signal supplied to the driving device. Therefore, when the electrical signal supplied to the driving device repeats a periodic change, if the light receiving position of the scattered light is detected at a predetermined time interval by the first light receiving sensor, the rotation angle of the mirror portion becomes a predetermined angle. In other words, the light receiving position of the scattered light in the first light receiving sensor is detected. That is, the coordinate data calculation means does not need to acquire the rotation angle of the mirror portion detected by the mirror rotation angle detection means. Accordingly, a timing shift between when the coordinate data calculation unit acquires the rotation angle of the mirror unit and when the scattered light reception position of the first light receiving sensor is acquired after the rotation angle of the mirror unit is acquired. Therefore, measurement accuracy can be improved. Further, if the time interval at which the first light receiving position detecting means detects the light receiving position of the scattered light is changed according to the intensity of the electric signal supplied from the driving device to the mirror part, that is, the rotation angle of the mirror part, Similarly to the above, the measurement accuracy can be changed depending on the measurement range of the measurement object.

1 is an overall schematic diagram of a three-dimensional shape measuring apparatus according to a first embodiment of the present invention. It is a front view of the three-dimensional camera of FIG. It is a top view of the three-dimensional camera of FIG. It is a front view of the 1st mirror of FIG. It is the graph which showed an example of the drive signal which drives the 1st mirror. It is the graph which showed the other example of the drive signal which drives a 1st mirror. It is a block diagram which shows the structure of the mirror angle detection circuit of FIG. It is a flowchart of the three-dimensional shape measurement process which a controller performs. It is a block diagram which shows the structure of the light reception sensor and mirror angle detection circuit which concern on 2nd Embodiment of this invention. It is a graph which shows the change of the output level of the adder of FIG. It is a graph which shows the value of the digital data memorize | stored in the memory of FIG. FIG. 8 is an enlarged view showing a light receiving position of reflected light in the photodetector of FIG. 7. It is the schematic which showed the apparatus for detecting the angle of the 1st mirror which concerns on 3rd Embodiment of this invention. FIG. 6 is an enlarged view of a state in which line-shaped reflected light is received by one photodetector. It is an enlarged view of a state in which line-shaped reflected light is evenly received by two photodetectors. FIG. 11B is an enlarged view showing a state in which line-shaped reflected light is received by the photodetector on the opposite side to FIG. 11A. It is a block diagram which shows the structure of the mirror rotation angle detection circuit which concerns on 3rd Embodiment of this invention. It is a flowchart of the three-dimensional shape measurement process which concerns on the modification of this invention and a controller performs. FIG. 10 is a block diagram showing a configuration of a control circuit for controlling the rotation angle of the first mirror according to another modification of the present invention.

a. First Embodiment A three-dimensional shape measuring apparatus according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, this three-dimensional shape measuring apparatus irradiates a measurement object OB while scanning a laser beam, and receives reflected light (scattered light) from the measurement object OB due to the irradiation. A camera CA is provided.

  The three-dimensional camera CA includes a housing 30 that includes a laser light source 10, a collimating lens 12, a first mirror 14, a second mirror 16, an imaging lens 18, and a light receiving sensor 20. Laser light emitted from the laser light source 10 is applied to the measurement object OB via the collimating lens 12 and the first mirror 14. Then, the reflected light (scattered light) from the measurement object OB is guided to the light receiving sensor 20 through the second mirror 16 and the imaging lens 18 to be received. The housing 30 also includes a laser light source 22, a collimating lens 24, and a light receiving sensor 26. The laser light emitted from the laser light source 22 is applied to a surface (hereinafter referred to as a back surface) opposite to the surface that reflects the laser light from the collimating lens 12 of the first mirror 14 via the collimating lens 24. The The back surface of the first mirror 14 is also formed in a mirror shape that reflects the laser light, and the laser light reflected by this back surface is received by the light receiving sensor 26. The three-dimensional camera CA also includes a motor 32 that rotates the housing 30 and a speed reduction device 34.

  Here, the function and arrangement of each component constituting the three-dimensional camera CA will be described with reference to FIGS. 2A and 2B. FIG. 2A is a front view of the housing 30, and FIG. 2B is a plan view of the housing 30. In the following description, the up-down direction and the left-right direction of the housing 30 are defined as the up-down direction and the left-right direction in FIG. 2A. Moreover, let the depth direction of the housing | casing 30 be the up-down direction of FIG. 2B. That is, the upper side of FIG. 2B is the back side of the housing 30, and the lower side of FIG. 2B is the front side of the housing 30. In FIG. 2A, the measurement object OB is located on the front side of the paper surface and is not shown. Further, in FIGS. 2A and 2B, illustration of components arranged to overlap in the depth direction and the vertical direction is omitted.

  The laser light source 10 is fixed at the upper right of the upper portion of the housing 30 and emits laser light for measuring the distance from the three-dimensional camera CA to the measurement object OB in the left direction in the figure. The collimating lens 12 is fixed to the housing 30 on the laser emission port side of the laser light source 10 and converts the laser light from the laser light source 10 into parallel light. As shown in FIG. 3, the first mirror 14 includes a mirror 14 a that is rotatably supported around a rotation shaft 14 a 1 and a driving device 14 b that displaces the mirror 14 a to a rotation angle corresponding to the intensity of the supplied electric signal. It is the MEMS mirror formed integrally. The first mirror 14 has a housing 30 such that the mirror 14 a is positioned on the optical axis of the laser light from the collimating lens 12, and the optical axis of the laser light from the collimating lens 12 is orthogonal to the rotation axis of the mirror 14 a. It is fixed to. The laser light converted into parallel light by the collimator lens 12 is reflected by the mirror 14a and is directed outward from the opening 30a provided in the front part of the housing 30 and the opening FRa provided in the front part of the frame FR. It is emitted and irradiated to the measurement object OB. In the following description, the rotation axis of the mirror 14a is referred to as the X axis, and the optical axis of the laser light emitted from the laser light source 10 is referred to as the Y axis. An axis orthogonal to the X axis and the Y axis is referred to as a Z axis.

  The second mirror 16 is fixed to the housing 30 below the first mirror 14 and reflects reflected light (scattered light) from the measurement object OB diagonally downward to the right in FIG. 2A. The imaging lens 18 is fixed to the housing 30 below the collimating lens 12 and forms an image of the reflected light from the second mirror 16 on the light receiving sensor 20. The light receiving sensor 20 is fixed to the housing 30 below the laser light source 10 and receives reflected light from the measurement object OB via the second mirror 16 and the imaging lens 18. The light receiving sensor 20 is an area sensor in which a plurality of light receiving elements that output an electrical signal corresponding to the amount of received light are arranged in a planar shape.

  The laser light source 22 is fixed at the upper left of the upper portion of the housing 30 and emits laser light for detecting the rotation angle of the mirror 14a toward the back surface of the mirror 14a via the collimator lens 24. To do. The collimator lens 24 is fixed to the housing 30 between the laser light source 22 and the first mirror 14 in the upper left part of the upper portion of the housing 30, and converts the laser light incident from the laser light source 22 into parallel light. Convert. The laser beam reflected by the back surface of the mirror 14 a is received by the light receiving sensor 26. The light receiving sensor 26 is fixed to the upper part of the back surface of the housing 30 and receives the reflected light from the back surface of the mirror 14a. The light receiving sensor 26 is a line sensor in which a plurality of light receiving elements that receive reflected light at a position corresponding to the rotation angle of the mirror 14a and output an electrical signal corresponding to the amount of received light are arranged in a row. The area of the light receiving portion of each light receiving element is smaller than the spot of reflected light.

The housing 30 is supported by the frame FR of the three-dimensional camera CA so as to be rotatable around the Y axis by the shaft 30b. The shaft 30 b is assembled to the rotating shaft of the motor 32 via the speed reducer 34. In the motor 32, an encoder 32a that detects the rotation of the rotation shaft of the motor 32 and outputs a rotation detection signal indicating the rotation is incorporated. The rotation detection signal, z-phase signal phi _Z and, a predetermined small angle of rotation by the high level and mutually repeated low level [pi / 2, which is generated each time the rotational position of the rotating shaft of the motor 32 comes to the reference rotational position It consists of a pulse train signal consisting of an A phase signal φ _A and a B phase signal φ _B that are out of phase by a certain amount.

  Further, this three-dimensional shape measuring apparatus includes a mirror angle detection laser drive circuit 38, a mirror drive circuit 40, a mirror angle detection circuit 42, a case drive circuit 44, a case angle detection circuit 46, and a shape measurement laser drive circuit 48. A sensor signal capturing circuit 50 and a controller 52 are also provided.

  When receiving a measurement start instruction from the controller 52, the mirror angle detection laser drive circuit 38 controls the drive signal so that a laser beam with a constant intensity is emitted from the laser light source 22, and supplies it to the laser light source 22. The mirror driving circuit 40 is controlled by the controller 52 and outputs a signal for driving the first mirror 14. The waveform of the signal for driving the first mirror 14 is preferably a triangular wave or sine wave as shown in FIG. 4A or 4B, and the rotation angle of the mirror 14a is changed to a triangular wave shape or a sine wave shape. The rotation angle of the mirror 14a corresponds to the instantaneous value of the drive signal waveform. As shown in FIG. 5, the mirror angle detection circuit 42 includes a sensor signal capturing circuit 42a and a rotation angle calculation circuit 42b. The sensor signal capturing circuit 42a converts the intensity of the signal output from each light receiving element of the light receiving sensor 26 at a constant time interval DT into digital data and supplies the digital data to the rotation angle calculating circuit 42b. As described above, since the area of each light receiving element is smaller than the area of the spot of the reflected light, the reflected light is received across the plurality of light receiving elements. When the rotation angle calculation circuit 42b is instructed to calculate the rotation angle θx from the controller 52, the rotation angle calculation circuit 42b generates waveform data representing the relationship between the position of each light receiving element and the signal intensity from the digital data supplied from the sensor signal capturing circuit 42a. The position of the light receiving element having the maximum signal intensity is obtained from the waveform data. The rotation angle calculation circuit 42b stores a table representing the relationship between the position of the light receiving element where the signal intensity is maximum and the rotation angle of the mirror 14a, and uses this table to calculate the rotation angle θx of the mirror 14a. Digital data representing the calculated rotation angle θx is output to the controller 52.

  The housing drive circuit 44 outputs a drive signal for driving the motor 32. The housing drive circuit 44 controls the drive signal so that the rotation speed of the motor 32 is constant. The motor 32 is supplied with a drive signal from the housing drive circuit 44 and rotates at a constant speed, and rotates the housing 30 via the speed reducer 34. The housing 30 rotates in a constant direction at a constant rotational speed from the start to the end of the three-dimensional shape measurement. The rotation speed of the housing 30 is slower than the rotation speed of the mirror 14a. The case angle detection circuit 46 receives the rotation detection signal from the encoder 32a, detects the rotation direction and the rotation speed of the case 30 using the pulse train signal of the input rotation detection signal, and The rotation angle θy is calculated. When instructed by the controller 52 to calculate the rotation angle θy of the casing 30, the case angle detection circuit 46 outputs digital data representing the calculated rotation angle θy to the controller 52. In addition, digital data representing the detected rotation direction and rotation speed of the casing 30 and the calculated rotation angle θy is also output to the casing drive circuit 44, and the rotation of the motor 32 by the casing drive circuit 44 during rotation driving. It is also used for speed control.

  When a measurement start instruction is input from the controller 52, the shape measurement laser drive circuit 48 controls the drive signal so that a laser beam with a certain intensity is emitted from the laser light source 10 and supplies it to the laser light source 10. The sensor signal capturing circuit 50 is connected to the light receiving sensor 20. When a capturing instruction is input from the controller 52, the sensor signal capturing circuit 50 captures a signal output from each light receiving element of the light receiving sensor 20 and outputs the signal to the controller 52.

  The controller 52 is configured by a microcomputer including a CPU, ROM, RAM, hard disk, and the like, and executes the three-dimensional measurement processing program shown in FIG. 6 in accordance with instructions from the input device 54 including a keyboard and a mouse. Then, by executing the program, the controller 52 performs a mirror angle detection laser drive circuit 38, a mirror drive circuit 40, a mirror angle detection circuit 42, a case drive circuit 44, a case angle detection circuit 46, and a shape measurement laser drive circuit. 48 and the sensor signal capturing circuit 50 are controlled, and three-dimensional image data of the measurement object OB is created, and a three-dimensional image of the measurement object OB is displayed on the display device 56.

  The light receiving sensor 20 may be a line sensor. In this case, the second mirror 16 may be omitted by making the mirror 14 a large enough to reach the position of the second mirror 16. Further, the second mirror 16 is a MEMS mirror whose mirror part is larger than the first mirror 14 in the direction perpendicular to the incident direction of the reflected light from the measurement object OB, and the second mirror 16 is rotated similarly to the first mirror 14. It may be driven. In this embodiment, the housing 30 is rotated in the direction perpendicular to the scanning direction of the laser beam by the first mirror 14 to scan the laser beam two-dimensionally. Any structure may be adopted as long as the laser light can be scanned in a direction perpendicular to the scanning direction of the laser light. For example, a long mirror whose rotation axis is the Y-axis direction is provided on the front side of the first mirror 14, and the laser beam reflected by the first mirror 14 is further reflected downward. And the opening part is provided in the lower surface side (lower side in FIG. 2A) of the housing | casing 30 and the flame | frame FR, and the measurement object OB is irradiated with the laser beam reflected by this elongate mirror. Then, the reflected light from the measurement object OB may be received by the light receiving sensor 20 through the long mirror, the second mirror 16 and the imaging lens 18. Further, instead of rotating the casing 30 around the Y axis, the three-dimensional camera CA may be translated in the X axis direction.

  Next, the operation of the three-dimensional shape measuring apparatus configured as described above will be described with reference to FIG. When the operator instructs to start measurement using the input device 54, the controller 52 starts a three-dimensional measurement process in step S10. Next, in step S11, the controller 52 initializes a measurement point number n representing the number of each measurement point to “0”. Next, in step S12, the controller 52 instructs the mirror drive circuit 40 and the case drive circuit 44 to set the rotation angle of the mirror 14a of the first mirror 14 and the case 30 to the initial rotation angle. In response to the instruction, the mirror driving circuit 40 and the housing driving circuit 44 rotate the mirror 14a and the housing 30 of the first mirror 14, and set the respective angles to the initial rotation angles.

  In step S13, the mirror angle detection laser drive circuit 38 and the shape measurement laser drive circuit 48 are instructed to start laser irradiation. In response to an instruction to start laser irradiation, the mirror angle detection laser drive circuit 38 and the shape measurement laser drive circuit 48 supply drive signals to the laser light source 22 and the laser light source 10, respectively, to emit laser light. Next, in step S14, the controller 52 instructs the mirror drive circuit 40 to start driving the mirror 14a. The mirror drive circuit 40 supplies a drive signal for the mirror 14 a to the first mirror 14 in response to an instruction to start driving. Thereby, the first mirror 14 starts to rotate around the X axis. Next, the controller 52 instructs the housing driving circuit 44 to start driving the housing 30 in step S15. As a result, the housing 30 starts to rotate around the Y axis. Next, the controller 52 starts time measurement in step S16.

  Next, in step S17, the controller 52 determines whether or not the current time has passed the time calculated by multiplying the measurement point number n and the predetermined time interval T. Initially, since the measurement point number n is initialized to “0”, “Yes” is determined in step S17, and the process proceeds to step S18. Next, in step S18, the controller 52 instructs the mirror angle detection circuit 42 to calculate the rotation angle θx of the mirror 14a. Then, the controller 52 takes in digital data representing the rotation angle θx of the mirror 14 a output from the mirror angle detection circuit 42.

  Next, the controller 52 instructs the housing angle detection circuit 46 to calculate the rotation angle θy of the housing 30 in step S19. Then, the controller 52 takes in digital data representing the rotation angle θy of the housing 30 output from the housing angle detection circuit 46. Next, the controller 52 instructs the sensor signal capturing circuit 50 to capture the output signal of the light receiving sensor 20 in step S20. Then, the controller 52 captures digital data that is output from the sensor signal capturing circuit 50 and represents the intensity of the signal output by each light receiving element of the light receiving sensor 20.

  Next, in step S21, the controller 52 determines whether or not the rotation angle θy acquired in step S19 is larger than a preset limit angle. The limit angle is an angle slightly smaller than the maximum angle at which the housing 30 can rotate. When the rotation angle θy is equal to or smaller than the limit angle, the process proceeds to step S22, the measurement point number n is incremented, and the process returns to step S17. Since the measurement point number n is “1” by the process of step S22, it is determined in step S17 whether the current time has passed T (ie, 1 × T). If the determination result is “No”, Step S17 is executed again. That is, step S17 is repeatedly executed until the determination result is “Yes”. Then, when the determination result in step S17 is “Yes”, the above steps S18 to S21 are executed. As described above, the controller 52 repeatedly executes Step S17 to Step S22 until the rotation angle θy reaches the limit angle. As described above, the rotation speed of the housing 30 is slower than the rotation speed of the mirror 14a, and the rotation angle θx of the mirror 14a changes substantially in a triangular wave shape or a sine wave shape depending on the input drive waveform. Therefore, the rotation direction of the mirror 14a is reversed many times while the steps S17 to S22 are repeated until the rotation angle θy of the housing 30 reaches the limit angle. As described above, the controller 52 irradiates the measurement object OB while scanning with the laser beam, repeatedly executes the processing including Step S17 to Step S22, and represents the rotation angle θx of the mirror 14a at a constant time interval T. Digital data, digital data representing the rotation angle θy of the housing 30, and digital data representing the intensity of the signal output from each light receiving element of the light receiving sensor 20 are captured. And the various digital data taken in are memorize | stored in RAM with which the controller 52 is provided for every measurement point number n.

  When the rotation angle θy of the housing 30 reaches the limit angle, the controller 52 instructs the mirror angle detection laser drive circuit 38 and the shape measurement laser drive circuit 48 to stop laser irradiation in step S23. In response to the laser irradiation stop instruction, the mirror angle detection laser drive circuit 38 and the shape measurement laser drive circuit 48 stop supplying the drive signals to the laser light source 10 and the laser light source 22, respectively. Stop irradiation. Next, the controller 52 instructs the mirror drive circuit 40 to stop driving the mirror 14a in step S24. The mirror drive circuit 40 stops the supply of the drive signal to the first mirror 14 in response to the drive stop instruction. Thereby, the rotation of the first mirror 14 is stopped. Next, the controller 52 instructs the housing drive circuit 44 to stop driving the housing 30 in step S25. The housing drive circuit 44 stops the supply of the drive signal to the motor 32 in response to the drive stop instruction. Thereby, the rotation of the housing 30 stops.

  Next, in step S26, the controller 52 uses the digital data representing the intensity of the signal output from each light receiving element of the light receiving sensor 20 stored in the RAM for each measurement point, and the principle of the triangulation method. Based on the above, distance data L representing the distance from the three-dimensional camera CA to the measurement object OB for each measurement point is calculated. Then, a coordinate data (x, y, z) group representing the surface shape of the measurement object OB is calculated using the distance data L, the rotation angle θx, and the rotation angle θy for each measurement point. Since the controller 52 captures various data at a constant time interval T, the x coordinate and y coordinate of each coordinate data calculated for each measurement point may not be equally spaced. In this case, the controller 52 performs an interpolation operation using the calculated coordinate data so that the x coordinate and the y coordinate are equally spaced. Then, three-dimensional image data for displaying a three-dimensional image of the measurement object OB on the display device 56 is created from the calculated coordinate data group. The created three-dimensional image data is supplied to the display device 56, and a three-dimensional image of the measurement object OB is displayed on the display device 56. And the controller 52 complete | finishes three-dimensional measurement in step S27.

  In the three-dimensional shape measuring apparatus configured as described above, the rotation angle θx of the mirror 14a is not calculated from the signal intensity supplied to the first mirror 14, but the back surface of the mirror 14a is irradiated with laser light. The reflected light is received by the light receiving sensor 26, and the rotation angle θx of the mirror 14a is detected from the light receiving position of the reflected light at the light receiving sensor 26. Therefore, even if a long period of time elapses from the start of use, even if the relationship between the strength of the electrical signal supplied to the first mirror 14 and the rotation angle of the mirror 14a changes, the accuracy of the acquired rotation angle does not change and the three-dimensional The accuracy of shape measurement can be maintained.

b. Second Embodiment A three-dimensional shape measuring apparatus according to a second embodiment includes a light receiving sensor 26A in place of the light receiving sensor 26 of the first embodiment. As shown in FIG. 7, the light receiving sensor 26 </ b> A is formed by arranging a plurality of photodetectors 26 </ b> A <b> 1 to 26 </ b> A <b> 9 that output electrical signals having an intensity corresponding to the amount of received light. However, the number of photodetectors constituting the light receiving sensor 26A is not limited to nine, and the light receiving sensor 26A may be configured by a larger number of photodetectors. Unlike the light receiving element constituting the light receiving sensor 26 of the first embodiment, the area of the light receiving part of each of the photodetectors 26A1 to 26A9 is larger than the area of the spot of the reflected light. In the second embodiment, a mirror angle detection circuit 42A is provided instead of the mirror angle detection circuit 42 of the first embodiment. The mirror angle detection circuit 42A includes amplification circuits 42c1 to 42c9, an adder 42d, an A / D converter 42e, and a rotation angle calculation circuit 42f. The signals output from the photodetectors 26A1 to 26A9 were amplified by the amplifier circuits 42cn (n = 1, 2,... 9) provided corresponding to the photodetectors 26An (n = 1, 2,... 9). Then, it is added by the adder 42d. The amplification factors of the amplifier circuits 42c1 to 42c9 are set so as to increase (or decrease) in this order, and the output levels of the amplifier circuits 42c1 to 42c9 are represented by output levels LV1 to LV9, respectively. Thereby, the photodetector that has received the reflected light can be identified from the output level of the adder 42d. When the spot of the reflected light from the back surface of the mirror 14a moves from the photo detector 26A1 toward the photo detector 26A9 by the rotation of the mirror 14a, the signal output from the adder 42d changes stepwise as shown in FIG. 8A. To do.

  The A / D converter 42e repeatedly converts the instantaneous value of the signal output from the adder 42d into digital data at a time interval DT and outputs the digital data to the rotation angle calculation circuit 42f. This time interval DT is shorter than the time interval T in which the controller 52 instructs the rotation angle calculation circuit 42f to calculate the rotation angle θx. The rotation angle calculation circuit 42f stores the digital data output from the A / D converter 42e in a memory 42f1 provided in the rotation angle calculation circuit 42f. The storage area of the memory 42f1 is divided into a plurality of storage areas (first area, second area... M-th area), and the rotation angle calculation circuit 42f calculates the rotation angle θx of the mirror 14a from the controller 52. Each time an instruction is input, the storage area for storing the digital data output from the A / D converter 42e is changed to the adjacent storage area. The digital data stored in each storage area is used for calculating the light receiving position of the reflected light, as will be described in detail later. Therefore, when the calculation of the light receiving position is completed, the storage area storing the digital data is released and new data can be stored.

  The rotation angle calculation circuit 42f specifies a photodetector that has received reflected light immediately after inputting an instruction to calculate the rotation angle θx, and calculates a light receiving position of the reflected light at the photodetector. Since the value of the digital data recorded in the memory 42f1 corresponds to one of the photodetectors 26A1 to 26A9, it is possible to specify which of the photodetectors 26A1 to 26A9 has received the reflected light. . As described above, the A / D converter 42e converts the output from the adder 42d into digital data at each time interval DT and supplies the digital data to the rotation angle calculation circuit 42f. Therefore, when a triangular wave or a sine wave is input as a driving signal for the first mirror 14, the light receiving position of the reflected light from the mirror 14a is assumed to move at a constant speed on one photo detector. Using the number of digital data representing that light is received, the moving speed at which the light receiving position moves (that is, during a predetermined time interval DT in which the A / D converter 42e converts the output of the adder 42d into digital data). The amount of movement of the reflected light can be calculated. Then, by multiplying the number of data from when the light is received by the specified photodetector until the instruction is input, the calculated moving speed, the light receiving position of the specified photodetector can be calculated.

  The method for calculating the light receiving position will be specifically described with reference to FIGS. 8B and 9. In this specific example, a calculation method of the light receiving position of the reflected light related to the data A recorded at the beginning of the eighth area of the memory 42f1 will be described. FIG. 8B is a graph showing the content of data stored in each storage area of the memory 42f1 when a sinusoidal drive signal is input as the drive signal for the first mirror 14. In FIG. 9, the light receiving position of the reflected light related to each data stored in the memory 42f1 is indicated by black dots, and the inside of the frame indicated by the broken lines of the photodetector 26A8 and the photodetector 26A9 is a light receiving portion capable of receiving laser light. is there. In this example, it is assumed that the light receiving position of the reflected light is moved from the left side to the right side in FIG. 9 (that is, from the photo detector 26A7 side to the photo detector 26A9 side). First, since the value of data A (that is, the output level of the adder 42d) is the output level LV8, the rotation angle calculation circuit 42f determines that the reflected light related to the data A is received by the photodetector 26A8. Next, the rotation angle calculation circuit 42f counts the number of the same value (that is, the output level LV8) stored in the data A before and after the data A is continuously stored. In this example, there are five data before the data A, and two data after the data A. Therefore, when data A is included, there are eight data indicating that light is received by the photodetector 26A8. Here, it is assumed that the light receiving positions related to the first data and the last data among the eight data are the left end and the right end of the light receiving portion of the photodetector 26A8, and the speed at which the reflected light moves on the photodetector 26A8 is constant. Consider it. When the width of the light receiving portion of one photodetector is L, the moving speed of the light receiving position is calculated as L / 7. Next, the rotation angle calculation circuit 42f multiplies the number of data recorded before the data A among the counted number of data by the calculated moving speed to obtain data from the left end of the light receiving unit of the photodetector 26A8. The distance to the light receiving position of the reflected light according to A is calculated. In this example, the number of data recorded before data A out of the counted number of data is 5, and the moving speed is L / 7. Therefore, when these are multiplied, 5L / 7 (= 5 × L / 7). Accordingly, the rotation angle calculation circuit 42f calculates that the light receiving position of the reflected light related to the data A is at a position that has entered the photodetector 26A8 side by 5L / 7 from the left end of the light receiving portion of the photodetector 26A8.

  However, when the specified photodetector is a photodetector located at both ends of the light receiving sensor 26A (that is, the photodetector 26A1 or the photodetector 26A9), the rotation direction of the mirror 14a is switched and the moving direction of the light receiving position of the reflected light is reversed. The moving speed of the light receiving position of the reflected light cannot be calculated depending on the number of digital data indicating that the light has been received by the specified photodetector. In this case, before or after the input of the instruction, the moving speed is calculated using the number of digital data indicating that the light is received by the photodetector adjacent to the specified photodetector (that is, the photodetector 26A2 or the photodetector 26A8). Then, by multiplying the calculated moving speed by the number of digital data indicating that light is received by the specified photo detector before or after the input of the instruction, the light receiving position in the specified photo detector can be calculated. it can.

  Next, a method for calculating the light receiving position when the moving direction is reversed will be specifically described with reference to FIGS. 8B and 9. In this specific example, a method of calculating the light receiving position of reflected light related to data B recorded at the beginning of the ninth area will be described. In this specific example, the light receiving position of the reflected light first moves from the left side of FIG. 9 to the right side (that is, from the photo detector 26A7 side to the photo detector 26A9 side), and then the moving direction is reversed on the photo detector 26A9. It is assumed that the right side of FIG. First, since the value of the data B is the output level LV9, the rotation angle calculation circuit 42f determines that the reflected light related to the data B is received by the photodetector 26A9. Next, the moving speed of the reflected light is calculated. Before the data B is recorded, the number of digital data indicating that light is received by the photodetector 26A8 located next to the photodetector 26A9 is counted. That is, it counts how many data whose value is the output level LV8 is continuously recorded. Then, there are 8 data that meet this condition. Here, assuming that the speed at which the reflected light moves on the photodetectors 26A8 and 26A9 is constant, and the width of the light receiving portion of one photodetector is L, the moving speed is L / 7.

  Next, the rotation angle calculation circuit 42f determines whether or not the moving direction of the reflected light has already been reversed. Specifically, the number of the same value (that is, the output level LV9) stored in the data B before and after the data B is continuously counted. Of the counted data numbers, the number of data stored before data B is compared with the number of data stored after data B. If the former is larger, the moving direction is If the latter is determined to be more, it is determined that the moving direction has not been reversed yet. When the moving direction of the light receiving position of the reflected light is reversed, a value obtained by multiplying the number of data recorded after the data B and the calculated moving speed is the data B from the left end of the light receiving unit of the photodetector 26A9. It is the distance to the light receiving position of the reflected light concerning. On the other hand, when the moving direction of the light receiving position of the reflected light is not yet reversed, the number of data stored before data B out of the counted number of data is multiplied by the calculated moving speed. The obtained value is the distance from the boundary between the photo detector 26A8 and the photo detector 26A9 to the light receiving position of the reflected light related to the data B. In this example, since the former is four and the latter is one, it is determined that the moving direction of the reflected light is reversed. Further, as described above, after the data B, one piece of data whose value is the output level LV9 is recorded and the moving speed is L / 7. Therefore, when these are multiplied, L / 7 (= 1 × L / 7). Therefore, it is possible to calculate that the light receiving position of the reflected light related to the data B is a position that has entered the photo detector 26A9 side by L / 7 from the left end of the light receiving unit of the photo detector 26A9.

  Then, the rotation angle calculation circuit 42f calculates the rotation angle θx of the mirror 14a by using a table showing the relationship between the light receiving position of the reflected light and the rotation angle θx in the light receiving sensor 26A, and represents the rotation angle θx of the mirror 14a. The digital data is output to the controller 52. The configuration of the second embodiment is the same as that of the first embodiment except for the light receiving sensor 26A and the mirror angle detection circuit 42A, and this second embodiment also provides the same effects as the first embodiment. . In the above description, in order to simplify the description and make it easy to understand, the number of data stored when there is a light receiving position of the reflected light on one photo detector is about eight. However, it is actually preferable to store more data. According to this, the accuracy of the light receiving position to be detected can be increased, and the accuracy of the calculated rotation angle θx can be increased.

c. Third Embodiment In the third embodiment, as shown in FIG. 10, a cylindrical lens 58 is provided between the collimating lens 24 of the first embodiment and the first mirror 14. The laser light emitted from the laser light source 22 and transmitted through the collimator lens 24 to become parallel light is transmitted through the cylindrical lens 58 to become line light. Further, a light receiving sensor 26B is provided instead of the light receiving sensor 26 of the first embodiment. The light receiving sensor 26B is formed by arranging two photodetectors that output an electric signal having an intensity corresponding to the amount of light received. The laser light that has passed through the cylindrical lens 58 and became line light is reflected by the back surface of the mirror 14a, and is received across the boundary between the two photodetectors 26B1 and 26B2, as shown in FIGS. 11A to 11C. Even when the moving direction of the light receiving position in the light receiving sensor 26B changes in the opposite direction, the reflected light is received across the boundary between the two photodetectors 26B1 and 26B2. Further, a mirror angle detection circuit 42B is provided instead of the mirror angle detection circuit 42. The mirror angle detection circuit 42B includes a differential amplifier circuit 42g, an A / D converter 42h, and a rotation angle calculation circuit 42i. The differential amplifier circuit 42g amplifies the difference in intensity between the signals output from the two photodetectors 26B1 and 26B2, and outputs the amplified difference to the A / D converter 42h. The A / D converter 42h converts the instantaneous value of the signal output from the differential amplifier circuit 42g into digital data at the time interval DT and outputs the digital data to the rotation angle calculation circuit 42i. The rotation angle calculation circuit 42i stores a table representing the relationship between the value obtained by amplifying the difference in the intensity of the signal output from the two photodetectors 26B1 and 26B2 and the rotation angle of the mirror 14a, and using this table, the mirror 14a is stored. The rotation angle θx is calculated, and digital data representing the rotation angle θx is output to the controller 52. The configuration of the third embodiment is the same as that of the first embodiment except for the cylindrical lens 58, the light receiving sensor 26B, and the mirror angle detection circuit 42B.

  According to the third embodiment configured as described above, it is not necessary to obtain the peak position as in the first embodiment. Further, unlike the second embodiment, it is not necessary to calculate the light receiving position by counting the number of data. Therefore, the rotation angle θx can be calculated at a higher speed than in the first and second embodiments. Note that the differential amplifier circuit 42g may output a signal obtained by dividing the difference in intensity of the signals output from the photodetectors 26B1 and 26B2 by the added value of the intensity of the signals output from the photodetectors 26B1 and 26B2. In this case, the rotation angle calculation circuit 42i may store a table representing the relationship between the intensity ratio of the signals output from the photodetectors 26B1 and 26B2 and the rotation angle θx. According to this, the rotation angle calculation circuit 42i can obtain the rotation angle θx of the mirror 14a using the intensity ratio of the signals output from the photodetectors 26B1 and 26B2, and therefore the intensity of the laser light emitted from the laser light source 22 Need not be kept constant. Therefore, the circuit configuration of the laser light source 22 can be simplified.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  In the above-described embodiment, the controller 52 has the digital data corresponding to the intensity of the signal output from each light receiving element of the light receiving sensor 20 at a certain time interval T, the digital data representing the rotation angle θx of the first mirror 14 and the housing. Digital data representing the rotation angle θy of the body 30 was taken in. However, every time the rotation angle of the first mirror 14 reaches a preset angle θx (n), various digital data may be captured. However, the parameter n is a variable that sequentially increases by “1” from “1” to “N”. Further, the value of the set angle θx (n) is sequentially increased as the value of the parameter n is increased.

  In this case, the controller 52 continues to sequentially input digital data representing the rotation angle θx of the mirror 14a output from the mirror angle detection circuit 42, and the input rotation angle θx becomes a preset set angle θx (n). At this time, the digital data corresponding to the intensity of the signal output from each light receiving element of the light receiving sensor 20 and the rotation angle θy of the housing 30 output from the housing angle detection circuit 46 may be captured. In this case, it may be configured as in the third embodiment in which digital data of the rotation angle θx can be obtained at high speed.

  The operation of the three-dimensional shape measuring apparatus configured as described above will be described with reference to FIG. When the operator instructs to start measurement using the input device 54, the controller 52 starts the three-dimensional measurement process in step S100. Next, the controller 52 initializes the parameter n to “1” in step S101. Next, the controller 52 instructs the casing drive circuit 44 to set the rotation angle θy of the casing 30 to the initial rotation angle in step S102. Next, in step S103, the controller 52 instructs the mirror angle detection laser drive circuit 38 and the shape measurement laser drive circuit 48 to start laser irradiation. Next, in step S104, the controller 52 instructs the mirror drive circuit 40 to start driving the mirror 14a. Thereby, the mirror 14a starts to rotate around the X axis. Next, in Step S105, the controller 52 instructs the mirror angle detection circuit 42B to calculate the rotation angle θx of the mirror 14a. Then, the controller 52 takes in digital data representing the rotation angle θx of the mirror 14a output from the rotation angle calculation circuit 42i. In step S106, the controller 52 determines whether or not the rotation angle θx is smaller than the set angle θx (1). When it is determined that the rotation angle θx is larger than the set angle θx (1), the process returns to step S105, and the rotation angle θx of the mirror 14a is captured again. In this manner, Step S105 and Step S106 are repeated until the rotation angle θx of the mirror 14a becomes smaller than the predetermined set angle θx (1).

  When the rotation angle θx of the mirror 14a becomes smaller than the set angle θx (1), the controller 52 instructs the housing drive circuit 44 to start driving the housing 30 in step S107. As a result, the housing 30 starts to rotate around the Y axis. Next, in step S108, digital data representing the rotation angle θx of the mirror 14a is captured in the same manner as in step S105. Next, in step S109, the controller 52 determines whether or not the rotation angle θx captured in step S108 is larger than the set angle θx (n). Initially, since the value of the parameter n is “1”, it is determined whether or not the rotation angle θx is larger than the set angle θx (1). When it is determined that the rotation angle θx captured in step S108 is smaller than the set angle θx (1), the controller 52 returns to step S108 and captures the rotation angle θx of the mirror 14a again. Thus, the controller 52 repeats steps S108 and S109 until the rotation angle θx of the mirror 14a becomes larger than the set angle θx (1).

  When the rotation angle θx of the first mirror 14 becomes larger than the set angle θx (1), the controller 52 instructs the case angle detection circuit 46 to calculate the rotation angle θy of the case 30 in step S110. To do. Then, the controller 52 captures digital data representing the rotation angle θy of the housing 30 output from the housing angle detection circuit 46. Next, the controller 52 instructs the sensor signal capturing circuit 50 to capture the output signal of the light receiving sensor 20 in step S111. The controller 52 captures digital data corresponding to the intensity of the signal output from each sensor element of the light receiving sensor 20 output from the sensor signal capturing circuit 50. Next, in step S112, the controller 52 determines whether or not the value of the parameter n is “N”. Initially, since the value of the parameter n is “1”, it is determined as “No” in step S112, the process proceeds to step S113, and the parameter n is incremented. As a result, the value of the parameter n becomes “2”. Next, the controller 52 determines in step S114 whether or not the rotation angle θy of the housing 30 has reached the limit angle. When the rotation angle θy of the housing 30 has not reached the limit angle, “No” is determined in step S114, and the process returns to step S108. Since the rotation speed of the housing 30 is slower than the rotation speed of the first mirror 14, the controller 52 repeatedly executes the processing from step S108 to step S114 while increasing the parameter n by “1”. Then, the value of the parameter n reaches “N” before the rotation angle θy of the housing 30 reaches the limit angle. At this time, the controller 52 determines “Yes” in step S112 and proceeds to step S115.

  Next, the controller 52 determines whether or not the rotation angle θy of the housing 30 has reached the limit angle in step S115. In step S115, if the rotation angle θy of the housing 30 has not reached the limit angle and it is determined “No”, the controller 52 in step S116, as in step S105, the current rotation angle of the mirror 14a. Capture θx. In step S117, the controller 52 determines whether or not the rotation angle θx captured in step S116 is equal to or less than the set angle θx (N). As described above, the rotation direction of the mirror 14a is reversed according to the drive waveform. That is, the rotation angle θx of the mirror 14a becomes slightly larger than the set angle θx (N) and then decreases again. Therefore, the controller 52 repeats the processing consisting of step S116 and step S117, and waits until the rotation angle θx of the mirror 14a becomes equal to or less than the set angle θx (N).

  When the rotation angle θx of the mirror 14a becomes equal to or less than the set angle θx (N), the controller 52 determines the rotation angle θy of the housing 30 from the housing angle detection circuit 46 in step S118, as in step S110. Capture digital data to represent. Next, in step S119, the controller 52 captures digital data corresponding to the intensity of the signal output from each light receiving element of the light receiving sensor 20 from the sensor signal capturing circuit 50 in the same manner as in step S111. Next, in step S120, the controller 52 determines whether or not the value of the parameter n is “1”. Since the current value of the parameter n is “N”, the controller 52 determines “No” in step S120, proceeds to step S121, and decrements the value of the parameter n. As a result, the value of the parameter n becomes “N−1”.

  Next, in step S115, the controller 52 determines whether or not the rotation angle θy of the housing 30 has reached the limit angle. If the limit angle has not been reached, the controller 52 proceeds to step S116 again. As described above, while the rotation angle θx of the mirror 14a is increasing, the process consisting of steps S108 to S113 is repeatedly executed to acquire various data, and while the rotation angle θx of the mirror 14a is decreasing. The process consisting of steps S116 to S121 is repeatedly executed to capture various data.

  When the rotation angle θy of the casing 30 reaches the limit angle and it is determined “Yes” in step S114 or step S115, the controller 52 performs the same processing as in steps S21 to S27 of the first embodiment. To do. That is, the controller 52 stops the laser irradiation from the laser light source 10 and the laser light source 22 in step S122. Next, in step S123, the drive of the first mirror 14 is stopped. In step S124, the driving of the housing 30 is stopped. Next, in step S125, the controller 52 uses the digital data corresponding to the intensity of the signal output from each light receiving element of the light receiving sensor 20 at each measurement point captured in step S111 and step S119, to obtain a three-dimensional camera. Distance data L representing the distance from the CA to the measurement object OB is calculated, and coordinate data representing the shape of the measurement object OB is calculated from the distance data L, the rotation angle θx, and the rotation angle θy. Further, three-dimensional image data for displaying a three-dimensional image of the measurement object OB on the display device 56 is created from the calculated coordinate data. And a measurement is complete | finished in step S126.

  According to the three-dimensional shape measuring apparatus configured as described above, every time the rotation angle θx of the mirror 14a becomes a preset set angle θx (n) (where n = 1, 2,... N). The data for calculating the rotation angle θy of the housing 30 and the distance data L from the three-dimensional camera CA to the measurement object can be taken in, and coordinate data can be calculated using these. Therefore, the measurement accuracy can be changed depending on the measurement range of the measurement object OB. That is, in the range where the change in shape is large and the measurement accuracy is desired to be high, the interval of the set angle θx (n) is set finely. Conversely, in the range where the measurement accuracy may be low without much change in shape, The interval of the set angle θx (n) may be set coarsely. Thereby, since the data amount of measurement data can be suppressed to the minimum necessary, coordinate data can be calculated at high speed compared with the case where the entire measurement range is measured with high accuracy.

  In the above-described embodiment and its modification, the mirror drive circuit 40 supplies the first mirror 14 with a triangular wave or sine wave drive signal. However, by correcting the drive signal using the current rotation angle θx of the mirror 14a acquired by the light receiving sensor, the rotation angle θx of the mirror 14a is changed into an ideal state waveform (for example, a triangular wave or It may be changed by a sine wave), and various digital data may be captured at a predetermined time interval.

  In this case, for example, as shown in FIG. 14, the laser light source 22, the collimating lens 24, the cylindrical lens 58, the light receiving sensor 26B, the mirror angle detection laser driving circuit 38, the mirror driving circuit 40, and the like as in the third embodiment. A differential amplifier circuit 42g is provided. Further, the mirror drive circuit 40 is a mirror drive circuit 40A including a mirror drive signal generation circuit 40a, a deviation correction signal generation circuit 40b, an adder 40c, and a drive circuit 40d. The mirror drive signal generation circuit 40a generates and outputs a signal corresponding to a signal for driving the mirror 14a. The deviation correction signal generation circuit 40b converts the signal output from the differential amplifier circuit 42g into a signal corresponding to the drive signal corresponding to the current rotation angle θx of the mirror 14a, and the converted signal and mirror drive signal generation circuit. A correction signal is generated and output such that the difference from the signal output by 40a is "0". The adder 40c adds the signal from the mirror drive signal generation circuit 40a and the signal from the shift correction signal generation circuit 40b and outputs the result. The drive circuit 40d generates a drive signal for driving the mirror 14a based on the signal from the adder 40c and supplies the drive signal to the first mirror 14. The signal supplied to the deviation correction signal generation circuit 40b as the current rotation angle θx of the mirror 14a is the rotation angle θx output by the mirror angle detection circuits 42 and 42A in the configuration of the first embodiment or the second embodiment. The digital data may be a signal converted into an analog signal. However, in this case, it is necessary to acquire the rotation angle θx and convert it to an analog signal at high speed.

  According to this, since the waveform of the change in the rotation angle θx of the mirror 14a is always in an ideal state, if the rotation angle θy of the housing 30 and the output of the sensor signal capturing circuit 50 are captured at a predetermined time interval, a predetermined rotation is obtained. Every time the angle θx is reached, the rotation angle θy of the housing 30 and the output of the sensor signal capturing circuit 50 are captured. Accordingly, step S18 in FIG. 6 can be omitted, and therefore, it is possible to eliminate a timing shift from taking in the rotation angle θx to taking in other data, which occurs when taking in the rotation angle θx of the mirror 14a. Thereby, the accuracy of the three-dimensional shape measurement can be further improved. Further, in order to calculate the rotation angle θy of the housing 30 and the distance data L from the three-dimensional camera CA to the measurement object OB according to the intensity of the signal output from the mirror drive signal generation circuit 40a, that is, the rotation angle of the mirror 14a. If the time interval for capturing the data is changed, the measurement accuracy can be changed depending on the measurement range of the measurement object OB, as in the case described above.

  In the above embodiment and its modification, the back surface of the mirror 14a is irradiated with laser light, and the reflected light is received by the light receiving sensors 26, 26A, and 26B. May be used as a minute spot or line light, reflected on the back surface of the mirror 14a, and the reflected light may be received by a light receiving sensor.

DESCRIPTION OF SYMBOLS 10 ... Laser light source, 12 ... Collimating lens, 14 ... 1st mirror, 20 ... Light receiving sensor, 22 ... Laser light source, 24 ... Collimating lens, 26, 26A, 26B ... Light receiving sensor, 30 ... Housing, 32 ... Motor, 32a DESCRIPTION OF SYMBOLS ... Encoder, 34 ... Deceleration device, 38 ... Laser drive circuit for mirror angle detection, 40 ... Mirror drive circuit, 42, 42A, 42B ... Mirror angle detection circuit, 44 ... Housing drive circuit, 46 ... Housing angle detection circuit, 48 ... shape measurement laser drive circuit, 52 ... controller, 58 ... cylindrical lens, OB ... measurement object

Claims (5)

A laser light source that emits laser light toward the measurement object;
Laser beam emission direction changing means for changing the emission direction of the laser beam emitted from the laser light source and causing the laser beam to scan the surface of the measurement object;
An emission direction detecting means for detecting an emission direction of the laser beam to the measurement object by the laser beam emission direction changing means;
A first light receiving sensor for receiving scattered light reflected by the surface of the measurement object;
First light receiving position detecting means for detecting a light receiving position of the scattered light in the first light receiving sensor;
Based on the principle of triangulation, the surface of the measurement object is measured using the emission direction of the laser beam detected by the emission direction detection unit and the light receiving position of the scattered light detected by the first light receiving sensor. In a three-dimensional shape measuring apparatus comprising coordinate data calculating means for calculating three-dimensional coordinate data representing a shape,
The laser beam emission direction changing means is
A first reflection surface that is rotatably supported around a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source, and a second reflection that reflects a light beam different from the laser light. A mirror unit having a surface, and a mirror integrally formed with a driving device that rotates and displaces the mirror unit around the rotation axis according to an electric signal supplied;
The emission direction detecting means includes
Light beam emitting means for emitting the light beam toward the second reflecting surface of the mirror;
A second light receiving sensor for receiving reflected light of the light beam from the second reflecting surface ;
A plurality of light receiving elements that output light receiving signals having an intensity corresponding to the amount of received light are arranged in a line, and reflected light from the second reflecting surface is any one of the plurality of light receiving elements. A second light receiving sensor for receiving light by two light receiving elements;
Mirror rotation angle detection means for detecting a rotation angle of the mirror unit based on a light receiving position of the reflected light in the second light receiving sensor ;
A plurality of amplifiers provided corresponding to the plurality of light receiving elements, respectively, for amplifying the received light signals output from the plurality of light receiving elements and converting them to signal levels of different magnitudes;
An adder that outputs an addition signal obtained by adding the received light signals converted by the plurality of amplifiers;
A light receiving element that receives the reflected light from the second reflecting surface from the value of the light reception data stored in the storage means is stored in a storage means that stores the value of the addition signal as light reception data at a constant time interval. And the number of received light data continuously stored before and after storing the received light data used for specifying the light receiving element. And a mirror having angle calculation means for calculating a light receiving position of reflected light from the second reflecting surface in the second light receiving sensor and calculating a rotation angle of the mirror unit based on the calculated light receiving position. A three-dimensional shape measuring apparatus comprising: a rotation angle detecting unit ; A laser light source that emits laser light toward the measurement object;
Laser beam emission direction changing means for changing the emission direction of the laser beam emitted from the laser light source and causing the laser beam to scan the surface of the measurement object;
An emission direction detecting means for detecting an emission direction of the laser beam to the measurement object by the laser beam emission direction changing means;
A first light receiving sensor for receiving scattered light reflected by the surface of the measurement object;
First light receiving position detecting means for detecting a light receiving position of the scattered light in the first light receiving sensor;
Based on the principle of triangulation, the surface of the measurement object is measured using the emission direction of the laser beam detected by the emission direction detection unit and the light receiving position of the scattered light detected by the first light receiving sensor. In a three-dimensional shape measuring apparatus comprising coordinate data calculating means for calculating three-dimensional coordinate data representing a shape,
The laser beam emission direction changing means is
A first reflection surface that is rotatably supported around a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source, and a second reflection that reflects a light beam different from the laser light. A mirror unit having a surface, and a mirror integrally formed with a driving device that rotates and displaces the mirror unit around the rotation axis according to an electric signal supplied;
The emission direction detecting means includes
A light source, and a light beam emitting means that emits the line light toward the second reflecting surface of the mirror, and a converter that converts light emitted from the light source into linear line light;
A second light receiving sensor for receiving the reflected light of the line light from the second reflecting surface, wherein two sensors for outputting a light receiving signal having an intensity corresponding to the amount of the received light are arranged side by side; A second light receiving sensor that receives the line light reflected by the two reflecting surfaces by the two sensors;
A three-dimensional shape measuring apparatus comprising: a mirror rotation angle detection unit having an angle calculation unit that calculates a rotation angle of the mirror unit using a difference in intensity between signals output from the two sensors . A laser light source that emits laser light toward the measurement object;
Laser beam emission direction changing means for changing the emission direction of the laser beam emitted from the laser light source and causing the laser beam to scan the surface of the measurement object;
An emission direction detecting means for detecting an emission direction of the laser beam to the measurement object by the laser beam emission direction changing means;
A first light receiving sensor for receiving scattered light reflected by the surface of the measurement object;
First light receiving position detecting means for detecting a light receiving position of the scattered light in the first light receiving sensor;
Based on the principle of triangulation, the surface of the measurement object is measured using the emission direction of the laser beam detected by the emission direction detection unit and the light receiving position of the scattered light detected by the first light receiving sensor. In a three-dimensional shape measuring apparatus comprising coordinate data calculating means for calculating three-dimensional coordinate data representing a shape,
The laser beam emission direction changing means is
A first reflection surface that is rotatably supported around a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source, and a second reflection that reflects a light beam different from the laser light. A mirror unit having a surface, and a mirror integrally formed with a driving device that rotates and displaces the mirror unit around the rotation axis according to an electric signal supplied;
The emission direction detecting means includes
Light beam emitting means for emitting the light beam toward the second reflecting surface of the mirror;
A second light receiving sensor for receiving reflected light of the light beam from the second reflecting surface;
Mirror rotation angle detecting means for detecting a rotation angle of the mirror unit based on a light receiving position of the reflected light in the second light receiving sensor ;
The first light receiving position detecting means detects the light receiving position of the scattered light in the first light receiving sensor when the rotation angle of the mirror portion detected by the mirror rotation angle detecting means is a predetermined angle. A characteristic three-dimensional shape measuring apparatus. A laser light source that emits laser light toward the measurement object;
Laser beam emission direction changing means for changing the emission direction of the laser beam emitted from the laser light source and causing the laser beam to scan the surface of the measurement object;
An emission direction detecting means for detecting an emission direction of the laser beam to the measurement object by the laser beam emission direction changing means;
A first light receiving sensor for receiving scattered light reflected by the surface of the measurement object;
First light receiving position detecting means for detecting a light receiving position of the scattered light in the first light receiving sensor;
Based on the principle of triangulation, the surface of the measurement object is measured using the emission direction of the laser beam detected by the emission direction detection unit and the light receiving position of the scattered light detected by the first light receiving sensor. In a three-dimensional shape measuring apparatus comprising coordinate data calculating means for calculating three-dimensional coordinate data representing a shape,
The laser beam emission direction changing means is
A first reflection surface that is rotatably supported around a rotation axis perpendicular to the optical axis of the laser light emitted from the laser light source, and a second reflection that reflects a light beam different from the laser light. A mirror unit having a surface, and a mirror integrally formed with a driving device that rotates and displaces the mirror unit around the rotation axis according to an electric signal supplied ;
The emission direction detecting means includes
Light beam emitting means for emitting the light beam toward the second reflecting surface of the mirror;
A second light receiving sensor for receiving reflected light of the light beam from the second reflecting surface;
Mirror rotation angle detecting means for detecting a rotation angle of the mirror unit based on a light receiving position of the reflected light in the second light receiving sensor ;
The laser beam emission direction changing unit changes the electric signal so that the rotation angle of the mirror portion detected by the mirror rotation angle detecting unit becomes a predetermined rotation angle corresponding to the electric signal supplied to the driving device. Further comprising an electric signal changing means
The three-dimensional shape measuring apparatus , wherein the first light receiving position detecting means detects a light receiving position of the scattered light in the first light receiving sensor at a predetermined time interval . In the three-dimensional shape measuring apparatus according to claim 3 or 4 ,
The second light receiving sensor is formed by arranging a plurality of light receiving elements that output a light receiving signal having an intensity corresponding to the amount of received light in a line, and receives reflected light from the second reflecting surface. Light is received by two or more light receiving elements adjacent to each other,
The mirror rotation angle detection unit identifies a light receiving element having the largest received light amount among the plurality of light receiving elements, and rotates the mirror unit based on a position of the identified light receiving element in the second light receiving sensor. A three-dimensional shape measuring apparatus comprising an angle calculating means for calculating.

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