JP6388384B2 - Measuring device and processing device - Google Patents

Description

The present invention, the measuring device, about your and processing equipment.

  A multi-axis non-contact three-dimensional measurement device (processing device) in which a probe head having a non-contact probe (first measurement device) is mounted on a spatially movable mechanism such as a three-axis drive stage or a rotary head is Since the object can be measured in a non-contact state, it is suitable for high-speed measurement. In such a processing apparatus, for example, a high-speed rotating mirror such as a galvanometer mirror is often employed as a mechanism for realizing high-speed scanning of length measuring light. A general galvanometer mirror has an encoder (second measuring device) that acquires position information of a mirror attached to a rotating shaft, and the encoder responds to a data acquisition trigger signal input from a control unit in the processing device. Position information. The control unit acquires the position information (measurement information) of each axis from an encoder attached to a mechanism such as a three-axis drive stage and a rotary head in synchronization with the length measurement information (measurement information) from a non-contact probe. From these data, the shape data of the test object is generated.

  However, the encoder and the non-contact probe have a processing circuit including a sensor such as a phototransistor, an analog circuit such as an amplification stage or a digital converter, and analog signal processing such as signal amplification is executed. Therefore, a delay time may occur between them. Such a delay time varies depending on changes over time such as a difference in circuit configuration for each encoder and non-contact probe and a temperature change. Therefore, a relative shift occurs in the timing of each axis for acquiring the position information of the encoder and the timing of acquiring the length measurement information of the non-contact probe, and an error may occur in measurement accuracy due to this shift.

  Therefore, Patent Document 1 discloses an encoder that estimates an error corresponding to a timing delay from acquired position data and adds the estimated error to the acquired position information to remove the influence of the delay. Patent Document 2 discloses a system that corrects a delay time by transmitting a signal related to the sampling operation timing in the encoder to a control unit and measuring the time of this signal. Patent Document 3 discloses a laser length measuring device that adjusts a delay of a filter circuit caused by a frequency change of an interference signal.

JP-A-8-261794 JP 2003-329485 A JP 2000-146513 A

  Here, in the techniques disclosed in Patent Documents 1 and 2, the deviation of the sampling operation timing in the encoder with respect to the information request pulse from the control unit is calibrated. However, it is difficult to strictly adjust the delay time of the analog portion such as the characteristic variation of the phototransistor and the amplification stage. On the other hand, with the technique disclosed in Patent Document 3, it is possible to adjust the delay of the filter circuit that causes a difference in frequency of interference signals. However, since the difference between the trigger signal and the actual digital conversion timing is measured internally and the relative deviation of the trigger signal and clock signal is not adjusted in consideration of the difference, there is room for improvement in terms of accuracy. is there.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a measurement device that is advantageous in terms of measurement accuracy, for example.

  In order to solve the above-described problems, the present invention provides a measuring device that measures the position of a test object based on the output of a sensor, and converts an analog signal that is the output of the sensor into a digital signal in response to a trigger signal. A first signal processing unit that outputs a digital signal and a trigger signal that is output to the first signal processing unit based on the measurement request signal and a digital signal that is output from the first signal processing unit in response to the trigger signal. The second signal processing unit includes a difference between the timing of the trigger signal and the timing of the digital signal converted from the analog signal according to the trigger signal by the first signal processing unit and output. Therefore, the trigger signal is output to the first signal processing unit before the measurement request signal.

  According to the present invention, for example, it is possible to provide a measurement device that is advantageous in terms of measurement accuracy.

It is a figure which shows the structure of the processing apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the control part in a processing apparatus. It is a figure explaining a structure and operation | movement of the probe head in a processing apparatus. It is a figure which shows the structure of the length measurement unit (measurement apparatus) which concerns on 1st Embodiment. It is a figure which shows the structure of the encoder (measurement apparatus) which concerns on 1st Embodiment. It is a flowchart which shows the flow of operation | movement of the processing apparatus which concerns on 1st Embodiment. It is a flowchart which shows the flow of the apparatus calibration process in FIG. It is a flowchart which shows the flow of the delay time adjustment process in FIG. It is a timing chart regarding the encoder which concerns on 1st Embodiment. It is a figure which shows structures, such as a sensor signal processing part of 2nd Embodiment. It is a flowchart which shows the flow of the delay time adjustment process of 2nd Embodiment. It is a timing chart regarding the encoder which concerns on 2nd Embodiment. It is a figure which shows structures, such as a sensor signal processing part of 3rd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, the measurement apparatus according to the first embodiment of the present invention and a processing apparatus including the measurement apparatus will be described. FIG. 1 is a schematic perspective view showing a configuration of a processing apparatus 1 that can include a plurality of measuring apparatuses according to the present embodiment. The processing apparatus 1 uses a component or a mold for manufacturing the component as a test object (measurement object) W, and measures the position of the test object W in a non-contact manner (measurement). Device. In each of the following drawings, an X axis and a Y axis perpendicular to each other are taken in a plane in a state where the object W is placed on the surface plate 2, and perpendicular to the XY plane (in this embodiment, the probe head). 11 and the test object W are facing each other). The processing apparatus 1 includes a drive stage and a control unit 12.

  The drive stage includes a surface plate 2, a Y carriage 3, an X slider 4, and a Z spindle 5 on which the probe head 11 is movable in the three axial directions of XYZ. The Y carriage 3 has a pair of leg portions extending in the Z-axis direction, and the upper ends (Z-axis direction plus side) of each other are connected by the X beam 6. The lower end of each leg of the Y carriage 3 (minus side in the Z-axis direction) is connected to air guides arranged on both sides of the surface plate 2, and the air guide can move the Y carriage 3 in the Y-axis direction. To support. The X beam 6 supports the X slider 4 movably in the X axis direction via an air guide. The X slider 4 supports the Z spindle 5 movably in the Z-axis direction via an air guide. The Z spindle 5 supports the probe head 11 via the rotary head 10 at the lower end thereof.

  The drive stage is a first measuring device according to the present embodiment for reading the XYZ position coordinates of the probe head 11, and a Y-coordinate measuring linear encoder 7; Each linear encoder for Z coordinate measurement is included. The linear encoder 7 for Y coordinate measurement is installed in the vicinity of one leg of the Y carriage 3. A linear encoder for X coordinate measurement is installed on the X beam 6. A linear encoder for measuring the Z coordinate is installed on the Z spindle 5.

  In addition, as a drive unit for moving the Y carriage 3 in the Y-axis direction, the drive stage has a Y shaft 13 installed on the surface plate 2 and a Y movable unit 8 installed on the Y carriage 3. As a drive unit for moving the X slider 4 in the X-axis direction, the drive stage has an X shaft 14 installed on the Y carriage 3 and an X movable unit 9 installed on the X slider 4. As a drive unit for moving the Z spindle 5 in the Z-axis direction, the drive stage has a Z shaft (not shown) installed on the X slider 4 and a Z movable unit (not shown) installed on the Z spindle 5. . Further, the drive stage has a rotary head 10 for changing the posture of the probe head 11 at the tip of the Z spindle 5. The rotary head 10 is capable of rotating around the Z axis (ωZ) and includes a rotary encoder as a second measuring device according to the present embodiment that measures the amount of rotation ωZ (not shown). A probe head 11 including a length measuring unit (non-contact probe) as a third measuring apparatus according to the present embodiment is installed at the tip of the rotary head 10. Each encoder and length measuring unit will be described in detail below. Further, the configuration of the above-described drive stage is an example, and for example, it may be configured by only some of the mechanisms.

  The control unit 12 transmits a drive command to each drive unit for each axial direction, the rotary head 10 and the probe head 11 to acquire and analyze the measurement information of each axis obtained along with the operation, and finally Thus, the shape of the test object W is obtained. FIG. 2 is a block diagram illustrating a configuration of the control unit 12. The control unit 12 includes a user interface (UI) 24, an environment measurement unit 39 that acquires environment information such as temperature and vibration, a main control unit 29, an arithmetic control unit 15, an X-axis control unit 16, and a Y-axis. A control unit 17, a Z-axis control unit 18, and a rotary head control unit (ωZ-axis control unit) 19 are included. The control unit 12 includes a ω1 axis control unit 20 and a ω2 axis control unit 21 that control a deflection mechanism in the probe head 11 and a length measurement unit control unit 22 that acquires a length measurement value.

  The main control unit 29 is electrically connected to each component (circuit) included in the control unit 12 and controls each process. In particular, in the present embodiment, the main control unit 29 transmits a measurement request start signal to each drive unit or the like in order to start acquisition of measurement information in the main measurement using each encoder and length measurement unit.

  Based on information input from the user interface 24, the arithmetic control unit 15 controls each control amount of the Y carriage 3, the X slider 4, the Z spindle 5, and the rotary head 10, the deflection mechanism in the probe head 11, and the length measurement value. The timing to acquire the is calculated. Here, the information input from the user interface 24 includes CAD information and measurement conditions. The arithmetic control unit 15 includes an X-axis control unit 16, a Y-axis control unit 17, a Z-axis control unit 18, a rotary head control unit 19, a ω1 axis control unit 20, a ω2 axis control unit 21, and a length measurement unit control unit 22. In addition, the calculated control amount and operation timing are transmitted as command values. The X-axis control unit 16, the Y-axis control unit 17, the Z-axis control unit 18, and the rotary head control unit 19 are based on the control amounts instructed from the calculation control unit 15, respectively. The Z-axis movable part and the rotary head 10 are driven. The ω1 axis control unit 20 and the ω2 axis control unit 21 drive the ω1 axis movable unit and the ω2 axis movable unit based on the control amounts instructed from the calculation control unit 15, respectively. The length measurement unit control unit 22 causes the length measurement unit to acquire length measurement information (length measurement value) based on the control signal instructed from the arithmetic control unit 15. The calculation control unit 15 calculates the position coordinates of the measurement points and the shape value of the test object W while correcting the reference values and the length measurement information of each axis with reference to the information acquired by the environment measurement unit 39. To do. The calculation control unit 15 can finally acquire the shape (surface shape) data of the test object W by repeating such an operation.

  Next, the probe head 11 including the length measuring unit will be described. FIG. 3 is a diagram for explaining the configuration and operation of the probe head 11. FIG. 3A is a schematic diagram showing the configuration of the probe head 11. The probe head 11 includes a length measuring unit 40 and a ω1-axis movable portion 25 and a ω2-axis movable portion 26 as deflection mechanisms that can rotate at high speeds. The length measuring unit 40 emits the light (beam) from the light source unit 41 as the length measuring light 23, and detects and calculates the light reflected on the object W, thereby calculating the object W. It is a non-contact probe that measures the position, more specifically, the distance to the test surface 28 on the test object W. The length measurement light 23 emitted from the length measurement unit 40 is reflected by the mirror surface 25A of the ω1-axis movable portion 25, and further reflected by the mirror surface 26A of the ω2-axis movable portion 26, and is irradiated on the test surface 28. The The light reflected by the test surface 28 follows the reverse optical path and returns to the length measuring unit 40. FIG. 3B is a timing chart for the rotation angles of the ω1-axis movable portion 25 and the ω2-axis movable portion 26. FIG. 3C is a diagram showing a scanning locus on the test surface 28 obtained by the operation based on the timing chart of FIG. When the rotation angle of the ω1 axis movable part 25 is rotated from ω1c to ω1d and the rotation angle of the ω2 axis movable part 26 is reciprocated between ω2a and ω2b according to FIG. 3B, FIG. Thus, two-dimensional scanning that proceeds in the Y-axis direction and repeats reciprocation in the X-axis direction is possible.

  FIG. 4 is a block diagram showing the configuration of the length measurement unit 40. Among these, FIG. 4A is a block diagram showing a configuration of the entire length measuring unit 40. As the length measuring unit 40, a probe having a contact type, optical type or capacitance type detection unit can be adopted. Here, an optical non-contact probe suitable for high-precision and high-speed measurement is used. And In addition, a heterodyne interferometer that can measure (measure) the distance to the object W with accuracy on the order of nanometers to micrometers by a measurement method using the principle of a laser interferometer shall be used. . The length measurement unit 40 includes a light source unit 41, a sensor signal processing unit 42, a digital signal processing unit 43, an input circuit 44, and an output circuit 45. The light source unit 41 emits an LED or a laser to generate desired light. The sensor signal processing unit (first signal processing unit) 42 includes a reference light generated by the light source unit 41 and modulated with the frequency fr, and a length measuring light that is modulated with the frequency fr and includes length measurement information of the test object W. Are converted into electrical signals. The digital signal processing unit (second signal processing unit) 43 performs arithmetic processing, division processing, correction processing, temporary storage, clock control, and the like on the digital signal obtained by the sensor signal processing unit 42. The input circuit 44 receives a signal from the digital signal processing unit 43. The output circuit 45 outputs a digital signal to the length measurement unit controller 22. Here, as the digital signal processing unit 43, an FPGA, an ASIC, a DSP, or the like that can process a digital signal at a high speed can be employed, and a microprocessor, a logic IC, or the like may be used in combination. Note that FPGA is an abbreviation for Field Programmable Gate Array. ASIC is an abbreviation for Application Specific Integrated Circuit. DSP is an abbreviation for Digital Signal Processor. The input circuit 44 and the output circuit 45 may be replaced by using a logic IC or by providing an equivalent function in the digital signal processing unit 43.

  FIG. 4B is a block diagram illustrating a configuration of the sensor signal processing unit 42. The sensor signal processing unit 42 includes a sensor 50, a signal control unit 51, a current / voltage conversion circuit 52, an amplification circuit 53, a low-pass filter 54, and an A / D conversion unit 55. The sensor 50 detects light, displacement, temperature, or the like and generates a current corresponding to the shape of the test object W. As the sensor 50, a photoelectric conversion element such as a photodiode or an avalanche photodiode that is advantageous for high-precision measurement can be employed. The signal control unit (third signal processing unit) 51 is installed on the output side of the sensor 50, and controls conduction of current generated by the sensor 50 with an external signal. The signal control unit 51 is preferably one that can be switched (switched) at a high speed based on an external signal. For example, a semiconductor element such as a transistor or a MOSFET is suitable. The current-voltage conversion circuit 52 converts the current output from the signal control unit 51 into an analog signal having a voltage value. The amplifier circuit 53 amplifies the analog signal transmitted from the current / voltage conversion circuit 52. The low-pass filter 54 removes noise included in the amplified analog signal transmitted from the amplifier circuit 53. The A / D converter 55 samples the analog signal that has passed through the low-pass filter 54 at a predetermined timing given from the outside, and converts it into a digital signal dig.

  Next, as a representative of an encoder that can be used for the Y movable portion 8, the X movable portion 9, the Z axis movable portion (not shown), the rotary head 10, the ω1 axis movable portion 25, or the ω2 axis movable portion 26, the ω2 axis movable portion. The encoder 30 for detecting the position 26 will be described.

  FIG. 5 is a block diagram showing the configuration of the encoder 30. Among these, FIG. 5A is a block diagram showing a configuration of the entire encoder 30. As the encoder 30, an encoder such as an optical type, a magnetic type, or a capacitance type can be used. Here, an optical that is highly accurate and responsive and is suitable for a movable part that is driven at high speed. An encoder of the type (rotary encoder). The encoder 30 includes a light source unit 31, a disk 32, a sensor signal processing unit 33, a digital signal processing unit 34, an input circuit 35, and an output circuit 36. The light source unit 31 emits light from a light emitting element 38 (see FIG. 5B) such as an LED or a laser to generate desired light. The disk 32 is rotatable around the central axis and has slits radially. The sensor signal processing unit (first signal processing unit) 33 receives light that has passed through the slit of the disk 32 and processes it into a desired signal according to the light receiving state. The encoder 30 calculates position information from two signal outputs of the A phase and the B phase that are 90 ° out of phase with each other. The digital signal processing unit (second signal processing unit) 34 performs arithmetic processing, division processing, correction processing, temporary storage, clock control, and the like on the digital signal obtained by the sensor signal processing unit 33. The input circuit 35 receives a signal from the ω2 axis control unit 21. The output circuit 36 outputs a digital signal to the ω2 axis control unit 21. The Y movable part 8, the X movable part 9 and the Z axis movable part adopt a linear encoder instead of a rotary encoder. In this case, a reflective or transmissive linear scale is used instead of the disk 32, respectively. A light emitting element and a light receiving element corresponding to this are arranged.

  FIG. 5B is a block diagram illustrating a configuration of the sensor signal processing unit 33. Since the basic configurations of the A-phase and B-phase sensor signal processing units 33 are the same, the following description will be made on behalf of the A-phase one. The sensor signal processing unit 33 includes a sensor 60, a signal control unit 61, a current / voltage conversion circuit 62, an amplification circuit 63, a low-pass filter 64, and an A / D conversion unit 65. The sensor 60 is a photoelectric conversion element that receives light from the light emitting element 38 in the light source unit 31 and generates a current corresponding to the amount of received light. The signal control unit (third signal processing unit) 61 controls conduction of current generated by the sensor 60 with an external signal. The signal control unit 61 is preferably one that can be switched at high speed based on an external signal. For example, a semiconductor element such as a transistor or a MOSFET is suitable. The current-voltage conversion circuit 62 converts the current output from the signal control unit 61 into an analog signal having a voltage value. The amplifier circuit 63 amplifies the analog signal transmitted from the current / voltage conversion circuit 62. The low pass filter 64 removes noise included in the amplified analog signal transmitted from the amplifier circuit 63. The A / D converter 65 samples the analog signal that has passed through the low-pass filter 64 at a predetermined timing given from the outside, and converts it into a digital signal dig.

  Next, the operation of the processing device 1 and each measuring device (the encoder 30 and the length measuring unit 40 as an example) will be described. FIG. 6 is a flowchart showing a flow of a series of operations of the processing apparatus 1. First, the control unit 12 executes a start-up sequence when a power source such as a power source or air is turned on (apparatus start-up step: step S100). Next, after the apparatus state is stabilized, the control unit 12 measures the reference device 100 (see FIG. 1) installed on the surface plate 2, for example. Then, the control unit 12 refers to the measurement value of the reference device 100 and executes device calibration such as calibration of each driving unit and adjustment of measurement information (position information or length measurement information) acquisition timing of the length measurement unit 40 ( Device calibration process: Step S200). Here, after the user installs the test object W on the surface plate 2, the control unit 12 then confirms the measurement conditions and the like for the test object W (test object installation process: step S300). Next, the control unit 12 performs main measurement (normal measurement) (main measurement step: step S400), and executes data processing such as calculation processing of the measurement result, display on a display, and storage of measurement information (data). Processing step: Step S500). After the measurement is completed, the control unit 12 next determines whether another measurement is to be continued (measurement end determination step: step S600). Here, when the control unit 12 determines that another measurement is to be performed (Yes), the test object W on the surface plate 2 is newly exchanged in Step S300, and the processes after Step S400 are repeated. . On the other hand, if the control unit 12 does not perform another measurement and determines that the measurement is ended here (No), after the removal of the test object W from the surface plate 2, the control unit 12 is turned off to shut off the power source. A sequence is executed (apparatus shutdown process: step S700), and a series of operations is terminated.

  Here, taking the encoder 30 as an example, the operation during the main measurement and the delay of the measurement data acquisition timing that may occur during the main measurement will be described with reference to FIG. First, in the main measurement of the encoder 30, the main control unit 29 transmits a measurement request start signal req_start to the ω2-axis control unit 21 in order to start acquisition of position information. Next, after receiving the measurement request start signal req_start, the ω2 axis control unit 21 transmits a position request pulse (first measurement request signal) req_w2 to the input circuit 35 of the encoder 30. The position request pulse req_w2e output from the input circuit 35 is input to the digital signal processing unit 34. Next, the digital signal processing unit 34 generates a sampling clock (sampling clock signal) sclk synchronized with the pulse req_w2e. The sampling clock sclk generated by the digital signal processing unit 34 is input to the A / D conversion unit 65. Then, the A / D conversion unit 65 samples the analog signal sg_sh that is a position information signal.

  However, in this measurement, the analog signal sg_sh is subjected to analog signal processing such as signal amplification until the output signal sg_pt of the sensor 60 reaches the A / D converter 65, and therefore the delay time td_e is Can occur. If no countermeasure is taken, such a delay time causes a relative shift in the timing of each axis for acquiring the position information of the encoder (or the timing for acquiring the length measurement information of the length measurement unit). An error may occur in measurement accuracy due to this deviation. Therefore, in this embodiment, in order to sample accurate position information when the position request pulse req_w2e is input, the pulse req_w2e and a delay time until sampling are measured in advance, and a value sampled prior to the pulse req_w2e. To get.

  FIG. 7 is a flowchart showing the flow of the apparatus calibration process in step S200 shown in FIG. In the stage of starting the apparatus calibration process, that is, in the main measurement process before adjusting the delay time described below, the signal circuit in the encoder 30 is in a closed state (step S210). In this state, the analog signal sg_sh corresponding to the amount of light received by the sensor 60 is digitally converted by the A / D converter 65 with a predetermined sampling clock sclk (see FIG. 5B). Specifically, the digital signal processing unit 34 outputs a trigger signal (first trigger signal) trig generated internally in accordance with the timing of the position request pulse req_w2e to the sensor signal processing unit 33. Then, the sensor signal processing unit 33 performs conversion into a digital signal at the rising edge of the sampling clock sclk when receiving the trigger signal (input timing). Upon receiving the converted digital signal dig, the digital signal processing unit 34 outputs the positional information acquired by the encoder 30 to the ω2 axis control unit 21.

  After step S210 is completed, the signal control unit 61 executes a delay time adjustment process (step S220). FIG. 8 is a flowchart showing the flow of the delay time adjustment process in the present embodiment. FIG. 9 is a timing chart of each signal related to the operation of the encoder 30. In the delay time adjustment step in the present embodiment, first, the A / D conversion unit 65 starts converting the analog signal sg_sh into the digital signal dig with the sampling clock sclk (step S221). However, if the A / D conversion unit 65 has already started digital conversion, it continues as it is. Next, the digital signal processing unit 34 transmits a trigger signal (second trigger signal) trig for opening the signal control unit 61 from the open state to the signal control unit 61 as shown in FIG. 9 (FIG. 5B). The analog signal is changed (see step S222). Specifically, the digital signal processing unit 34 obtains the position request pulse req_w2e from the outside (first step), and closes the signal control unit 61 with the trigger signal trig having the same rising edge as the obtained position request pulse req_w2e. (Second step). Next, the digital signal processing unit 34 counts the difference Δt between the timing (edge) at which the trigger signal trig is given and the timing at which the digital signal dig is detected in response to the change in the analog signal, and this difference is delayed. Let td_e. Then, the digital signal processing unit 34 generates a new position request pulse (second measurement request signal) req_w2m shifted by a delay time td_e before the position request pulse req_w2e given from the outside (third step: step) S223). Thus, unlike the first trigger signal, the trigger signal trig in the delay time adjustment step, that is, the second trigger signal is a unique signal used as a reference for obtaining a difference Δt from each timing. is there.

  After the end of step S220, the digital signal processing unit 34 generates a trigger signal (first trigger signal) trig according to the timing of the new position request pulse req_w2m as the main measurement process reflecting the adjustment of the delay time ( Update) and output to the sensor signal processing unit 33. Then, the sensor signal processing unit 33 performs conversion into a digital signal at the rising edge of the sampling clock sclk when receiving the trigger signal at this time. Receiving the converted digital signal, the digital signal processing unit 34 outputs the digital signal dig as position information of the encoder 30 (step S230). Next, when another calibration other than the delay time adjustment process executed in step S220 is required as another apparatus calibration process, the control unit 12 executes the calibration process (step S240). A series of steps is completed.

  In the example shown in FIG. 7, the delay time adjustment process is executed in the apparatus calibration process in step S200 shown in FIG. 6. For example, during the main measurement process in step S400 shown in FIG. It may be executed. Further, in the above description, the signal control unit 61 receives the trigger signal trig in step S222 and switches the circuit from open to closed. However, the signal control unit 61 may switch the circuit from closed to open.

  As described above, the measurement apparatus according to the present embodiment first dynamically varies the analog signal in the signal control unit using the trigger signal (second trigger signal) transmitted from the digital signal processing unit, and the variation. The timing difference is measured using a digital signal reflecting the above. Therefore, it is possible to suitably realize calibration of a measuring apparatus that corrects a deviation due to an electrical time delay of an analog signal such as a variation in characteristics of a phototransistor (sensor) and an amplification stage, which could not be achieved conventionally. The measuring device can measure or correct the circuit delay from the sensor to the digital conversion and the deviation amount of the sampling timing of the digital conversion, so that the measurement accuracy is high (the measurement error is small). Furthermore, the measurement apparatus can withstand temperature changes and long-time measurement by reflecting information from the environment measurement unit 39, for example.

  In the present embodiment, the processing apparatus 1 is a non-contact three-dimensional measurement apparatus that measures the position of the test object W in a non-contact manner, but is not limited thereto. For example, the processing apparatus 1 may be a three-dimensional processing apparatus that processes the test object W into a desired shape by laser light irradiation or the like. In this case, the probe head 11 is provided with, for example, a laser processing unit instead of the length measurement unit 40. In the present embodiment, the sensor is a photoelectric conversion element (light receiving element) that receives light from the light emitting element in the light source unit, but may be changed if the measurement method of each measuring device is different. . For example, the sensor may be an element that detects heat, magnetism, or the like, and the light source unit may be an element that emits heat, magnetism, or the like.

  As described above, according to the present embodiment, it is possible to provide a measurement device that is advantageous in terms of measurement accuracy. Moreover, according to the processing apparatus having the measuring apparatus according to the present embodiment, it is advantageous at least in terms of processing accuracy when processing (measurement, processing, etc.) the measurement target object and the processing target object.

(Second Embodiment)
Next, a measuring apparatus according to the second embodiment of the present invention will be described. In the measurement apparatus according to the first embodiment, referring to the encoder 30 of the ω2-axis movable unit 26, the trigger signal from the digital signal processing unit 34 (corresponding to the second trigger signal in the first embodiment) trig is a sensor signal. The signal is input to the signal control unit 61 in the processing unit 33. That is, the signal control unit that receives the trigger signal trig exists on the control circuit side. On the other hand, the measurement apparatus according to the present embodiment is characterized in that the signal control unit that receives the trigger signal trig is installed not on the control circuit side but on the light source unit 31, that is, the light irradiation side. This feature is also included in the encoder or probe head 11 that can be used for the Y movable part 8, the X movable part 9, the Z axis movable part, the rotary head 10 or the ω1 axis movable part 25 shown as the measuring device in the first embodiment. It can also be applied to length measuring units that can be used. Hereinafter, as in the first embodiment, as an example, a case where the features of this embodiment are applied to the encoder 30 of the ω2-axis movable unit 26 will be described. Moreover, in the following description, the same code | symbol is attached | subjected about what corresponds to each component and each signal of the measuring device 1 which concerns on 1st Embodiment, and description is abbreviate | omitted.

  FIG. 10 is a block diagram showing the configuration of the sensor signal processing unit 66 and the light source unit 67 in the present embodiment corresponding to the sensor signal processing unit 33 and the light source unit 31 in the first embodiment shown in FIG. is there. In this figure, the A-phase and B-phase sensor signal processing units 66 will be described as representative. Unlike the first embodiment, the sensor signal processing unit 66 does not have a signal control unit therein. In contrast, the light source unit 31 includes a signal control unit (third signal processing unit) 68 that is connected to the light emitting element 38 and receives the trigger signal trig from the digital signal processing unit 34. As the signal control unit 68, similarly to the signal control unit 61 in the first embodiment, for example, a semiconductor element such as a transistor or a MOSFET is suitable. The signal control unit 68 performs opening / closing by a trigger signal input to the light source unit 31, and controls ON / OFF of the light emitting element 38.

  FIG. 11 is a flowchart showing a flow in the case of this embodiment applied to the delay time adjustment step (step S220) shown in FIG. 7 in the first embodiment. FIG. 12 is a timing chart of each signal related to the encoder 30 in the present embodiment. In the main measurement before entering the delay time adjustment process of the encoder 30, the signal control unit 68 is closed and the light emitting element 38 is in a state of emitting light.

  In the delay time adjustment step in the present embodiment, first, the A / D conversion unit 65 converts the analog signal sg_sh into the digital signal dig with the sampling clock sclk−1 in which the rising edge is synchronized with the position request pulse req_w2e. Furthermore, as shown in FIG. 12, the digital signal processing unit 34 transmits a trigger signal trig whose rising edge is the same as that of the position request pulse req_w2e to the signal control unit 68, and the signal control unit 68 is changed from open to closed (first). Step and second step: Step S224). Next, the digital signal processing unit 34 counts the reference time T from the time of the edge of the trigger signal trig to the time when the digital signal dig-1 changes using the reference clock (reference clock signal) refclk (step S225). ). The state at this time corresponds to “state 1 (trig-1, dig-1)” in FIG. Next, the digital signal processing unit 34 delays the sampling clock sclk by one clock of the reference clock refclk, and causes the A / D conversion unit 65 to start A / D conversion. Further, the digital signal processing unit 34 transmits a trigger signal trig to the signal control unit 68, and closes the signal control unit 68 from open (step S226). Next, the digital signal processing unit 34 counts the time Ts from the time of the edge of the trigger signal trig to the time when the digital signal dig changes using the reference clock refclk (step S227). Next, when the digital signal processing unit 34 counts in step S227, the digital signal dig has changed from the timing T1 to the reference time T (less than the reference time T), that is, the relationship of Ts <T is satisfied. It is determined whether or not it is satisfied (step S228). If the digital signal processing unit 34 determines that the digital signal dig does not change, that is, does not satisfy the relationship of Ts <T (No), the digital signal processing unit 34 returns to step S226 to delay the sampling clock sclk, The steps up to S228 are repeated. The state at this time corresponds to “state 2 (trig-2, dig-2)” to “state 4 (trig-4, dig-4)” in FIG. On the other hand, if the digital signal processing unit 34 determines that the digital signal dig has changed in step S228, that is, satisfies the relationship of Ts <T (Yes), the delay amount Δt until the time T2 is set as the delay time td_e. (Step S229). Next, the digital signal processing unit 34 generates a new position request pulse req_w2m obtained by delaying T-Δt (shifted forward by Δt) from the rising edge of the position request pulse req_w2e (sampling clock sclk-1) ( Third step: Step S229). The state at this time corresponds to “state 5 (trig-5, dig-5)” in FIG. In the main measurement after the delay time adjustment process of the encoder 30 is completed, the digital signal processing unit 34 outputs the position information of the encoder 30 according to the position request pulse req_w2m.

  Thus, according to the present embodiment, even if the arrangement of the signal control unit that receives the trigger signal from the digital signal processing unit in the measurement apparatus is different from that in the first embodiment, the same as in the first embodiment. There is an effect.

(Third embodiment)
Next, a measurement apparatus according to the third embodiment of the present invention will be described. A feature of the measurement apparatus according to the present embodiment is that a signal control unit that receives a trigger signal (corresponding to the second trigger signal in each of the above embodiments) trig is included in the sensor signal processing unit in the case of the first embodiment. The point is that they are placed at different positions. This feature is also an encoder that can be used for the Y movable part 8, the X movable part 9, the Z axis movable part, the rotary head 10, the ω1 axis movable part 25, or the ω2 axis movable part 26 shown as the measuring device in the first embodiment. Or, it can be applied to a length measuring unit that can be used for the probe head 11. Hereinafter, as in the first embodiment, as an example, a case where the features of this embodiment are applied to the encoder 30 of the ω2-axis movable unit 26 will be described. Moreover, in the following description, the same code | symbol is attached | subjected about what corresponds to each component and each signal of the measuring device 1 which concerns on 1st Embodiment, and description is abbreviate | omitted.

  FIG. 13 is a block diagram showing a configuration of a sensor signal processing unit 69 in the present embodiment corresponding to the sensor signal processing unit 33 in the first embodiment shown in FIG. In this figure, the A-phase and B-phase sensor signal processing units 66 will be described as representative. Unlike the signal control unit 61 in the first embodiment that controls the conduction of the current generated by the sensor 60 by an external signal, the sensor signal processing unit 69 is installed on the input side of the sensor 60, and the bias current to the sensor 60 is A signal control unit 70 that controls conduction by an external signal is provided. As the signal control unit 70, for example, a semiconductor element such as a transistor or a MOSFET is suitable, like the signal control unit 61 in the first embodiment.

  In this case, referring to the flow of the delay time adjustment process in the second embodiment shown in FIG. 11, first, in the main measurement before entering the delay time adjustment process of the encoder 30, the signal control unit 70 is opened. Yes, the bias current does not flow. At this time, the A / D conversion unit 65 digitizes the analog signal sg_sh corresponding to the amount of light received from the sensor 60 with the sampling clock sclk-1 synchronized with the timing of the position request pulse req_w2e. Then, the digital signal processing unit 34 processes the input digital signal and outputs it as position information of the encoder 30. In the delay time adjustment step in the present embodiment, first, the digital signal processing unit 34 transmits a trigger signal trig for opening the signal control unit 70 from closed to the signal control unit 70. Then, the signal control unit 70 applies a bias current to the sensor 60, changes the analog signal from the sensor 60 by a trigger signal, and measures the delay amount td_e as in the case of the first embodiment. The bias current may be a forward bias current or a reverse bias current, and is given so as not to destroy the sensor 60 as the light receiving element and to change the analog signal. For example, the digital signal processing unit 34 or the main control unit 29 performs control such that a reverse bias current is applied to the sensor 60 in a state where the sensor 60 is not in a light receiving state. In the main measurement after the delay time adjustment process of the encoder 30 is completed, the digital signal processing unit 34 first stores the digital data sampled by the A / D conversion unit 65 for several clocks. Next, the digital signal processing unit 34 outputs, as position information of the encoder 30, data acquired by the delay time td_e before the position request pulse req_w2e given from the outside.

  Thus, according to this embodiment, even if the arrangement of the signal control unit that receives the trigger signal from the digital signal processing unit in the sensor signal processing unit in the measurement device is different from that in the first embodiment, The same effect as the first embodiment is achieved.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

30 Encoder 33 Sensor signal processing unit 34 Digital signal processing unit 40 Measuring unit 42 Sensor signal processing unit 43 Digital signal processing unit

Claims (11)

A measuring device that measures the position of an object based on the output of a sensor,
A first signal processing unit that converts an analog signal output from the sensor into a digital signal in response to a trigger signal and outputs the digital signal;
A second signal processing unit that outputs the trigger signal to the first signal processing unit based on a measurement request signal and receives the digital signal output from the first signal processing unit in response to the trigger signal. And
The second signal processing unit is equivalent to the difference between the timing of the trigger signal and the timing of the digital signal that is converted from the analog signal according to the trigger signal by the first signal processing unit and output. Outputting the trigger signal to the first signal processing unit before the measurement request signal;
A measuring device characterized by that.   The second signal processing unit receives the digital signal from the first signal processing unit according to the input timing of the trigger signal to the first signal processing unit and the input of the trigger signal. The measuring apparatus according to claim 1, wherein a difference from the receiving timing is obtained.   The first signal processing unit is provided on the output side of the sensor, and has a third signal processing unit that can switch conduction of current generated by the sensor by receiving the trigger signal. The measuring device according to claim 1 or 2.   The first signal processing unit includes a third signal processing unit which is installed on a bias current input side to the sensor and which can switch the conduction of the bias current by receiving the trigger signal. The measuring device according to claim 1 or 2.   The said 2nd signal processing part calculates | requires the timing which receives the said digital signal, counting using the sampling clock signal on the basis of the said trigger signal, The any one of Claim 2 thru | or 4 characterized by the above-mentioned. Measuring device.   The first signal processing unit includes a third signal processing unit that is connected to an element that emits an object to be detected by the sensor, and that can switch ON / OFF of the element by receiving the trigger signal. The measuring device according to claim 1, wherein:   The second signal processing unit obtains a timing at which a sampling clock signal is output while counting using a reference clock signal with the trigger signal as a reference, and based on the timing at which the sampling clock signal is output, The measuring apparatus according to claim 6, wherein a timing for receiving a signal is obtained.   The measurement apparatus according to claim 7, wherein the second signal processing unit outputs the reference clock signal.   The measuring apparatus according to claim 1, wherein the sensor is a light receiving element.   The measuring apparatus according to claim 3, wherein the third signal processing unit is a semiconductor element. A processing device for measuring or processing,
A measuring device according to any one of claims 1 to 10, comprising:
A processing apparatus that performs the measurement or the processing based on the position of the test object measured by the measurement apparatus.

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