A single field scanning time grating angular displacement measurement device

Abstract

The present application relates to the technical field of measuring equipment, and especially relates to a single-field scanning time grating angular displacement measuring device. The device comprises a light source body, a moving disc, a mask plate and a photoelectric detector. The moving disc is provided with a first periodic sector light-transmitting surface in the circumferential direction. The mask plate is arranged in parallel with the moving disc and is provided with a second periodic double-cosine light-transmitting surface in the circumferential direction. The first periodic sector light-transmitting surface and the second periodic double-cosine light-transmitting surface are not equal to each other, and under the optical superposition, the two form a third periodic amplitude light-transmitting surface. In a single amplitude period, a plurality of groups of phase-shifted amplitude modulation regions are continuously formed in the circumferential direction. The single-field scanning time grating angular displacement measuring device provided by the present application adopts a ring-shaped large-area scanning design, covers the mask plate and continuously works in multiple scanning fields, and the pollution only causes slight changes in the signal amplitude, does not cause phase distortion or measurement failure, and is suitable for complex working conditions.

Description

Technical Field

[0001] This invention relates to the field of measuring equipment technology, and in particular to a grating angular displacement measuring device during single-field scanning. Background Technology

[0002] A time-grating displacement sensor is a sensor that uses the principle of "space-time conversion" to measure displacement with high precision over time. In an optical field time-grating sensor, the periodically changing spatial light intensity signal formed by the superposition of the light-transmitting surfaces of the mask and the moving disk, combined with the time-modulated light intensity signal, is received by the detector and output as a photoelectric signal, thereby realizing the measurement of angular displacement.

[0003] In the field of optical grating angular displacement measurement, traditional techniques often employ photoelectric scanning based on moiré fringes. This method uses equally spaced rectangular gratings on a moving disk and a mask plate, which are superimposed to form a periodically changing spatial light intensity signal. The photoelectric reading unit scans the light-transmitting area superimposed on the disk, and by sensing the alternating changes in brightness of the gratings in the local area, it converts them into electrical signal pulses. The angular displacement of the disk is then derived based on pulse counting and grating parameters. However, since the light intensity variation superimposed on the rectangular light-transmitting surface exhibits a non-sinusoidal variation law, the harmonic components of the measurement are complex, making measurement error compensation difficult and thus requiring high physical precision in the original manufacturing process.

[0004] To address the aforementioned issues, existing technologies, such as the optical positioning device disclosed in CN114543663A, have optimized traditional solutions by employing a single-field scanning structure. This improves signal uniformity through a large-area scanning field, simplifies the assembly process, and enhances anti-fouling performance. However, the light-transmitting units of this device still employ equidistant rectangular or discrete structures, and the non-sinusoidal distortion of the light intensity modulation signal after the superposition of two gratings has not been fundamentally resolved. The difficulty of subdivision error compensation and the requirements for manufacturing precision remain high.

[0005] To address this issue, a single-field scanning grating angular displacement measuring device is designed to provide a technical solution for the aforementioned technical problems. This device generates purer, more stable, and more orthogonal sine and cosine signals, thereby laying a solid foundation for high-magnification electronic subdivision and ultimately achieving higher precision and higher reliability angular displacement measurement. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A grid angle displacement measuring device for single-field scanning includes:

[0008] The light source is used as the light source output to enable the output beam to be incident on the moving disk;

[0009] A photomask is installed on the back of the moving disk. The photomask has double cosine light-transmitting surfaces that are evenly and closely arranged in a circle.

[0010] A photodetector, mounted on the back of the photomask, is used to receive the optical signal generated by the interlacing of the photomask and the moving disk, and convert it into an electrical signal for output.

[0011] In a preferred embodiment of the single-field scanning grating angle displacement measuring device provided by the present invention, the moving disk is engraved with a fan-shaped light-transmitting surface symmetrical about the axis l along the circumferential direction. The radial height H of the fan-shaped light-transmitting surface corresponds to the distribution period P along the circumferential direction. bs It is configured to limit the intensity of the incident beam by the moving disk.

[0012] Furthermore, the radial height h of the double cosine light-transmitting surface is related to the second period P. zs Used to generate a continuously changing light intensity control signal during the rotation of the moving plate.

[0013] Furthermore, the periodicity of the light-transmitting surface of the moving disk Periodicity with the light-transmitting surface of the mask plate The following conditions must be met:

[0014] ;

[0015] .

[0016] Furthermore, the moving disk and the mask plate are modulated to form a radial height h, and the third period is P. zf The amplitude of the light-transmitting surface, the period P zf The conditions are as follows:

[0017] .

[0018] Furthermore, the light-transmitting surface of the moving disk has at least a period equal to that of the light-transmitting surface of the mask plate within the scanning cycle, as expressed below:

[0019] .

[0020] Furthermore, in the period P of the amplitude-transmitting surface zf Within, n sets of continuous amplitude-transmitting surfaces are formed, and the period of each set of transmitting surfaces satisfies the following condition:

[0021] .

[0022] Furthermore, the mask plate overlaps and intersects with the moving disk, along the circumferential direction at a distance of 1 / nP. sdn sets of amplitude-transmitting surfaces are periodically formed, and n sets of corresponding photodetector elements are arranged above them. Each of the n sets of amplitude-transmitting surfaces simultaneously receives all the light flux, generating incremental signals with phases increasing by 360° / n in sequence.

[0023] Through the above technical solutions, the present invention has at least the following beneficial effects:

[0024] This invention provides a single-field scanning grating angle displacement measuring device, which proposes a cosine-modulated single-field scanning method and combines it with alternating light intensity modulation to obtain a spatially modulated electric traveling wave signal. While reducing the harmonic components of the single-field scanning, it achieves high-resolution and high-precision angle measurement by means of high-frequency and high-precision clock pulse interpolation.

[0025] This invention utilizes the first cycle of the light-transmitting surface of the moving disk. Not equal to the second cycle of the photomask's light-transmitting surface Combined with the double cosine structure of the mask plate to form a periodic amplitude light-transmitting surface, it has the core advantages of wide coverage and continuous scanning. Contamination will only cause slight changes in signal amplitude and will not cause phase distortion, significantly improving the anti-contamination capability. At the same time, the sinusoidal light transmission characteristics formed by the period difference can generate a uniform photoelectric signal close to an ideal sine wave, which greatly reduces the single-cycle angle error caused by signal asymmetry and waveform distortion in traditional scanning, providing a high-quality signal foundation for high-magnification electronic subdivision.

[0026] This invention employs a large-area ring scanning design, where contamination will only cause slight changes in signal amplitude and will not lead to phase distortion or measurement failure, making it suitable for complex working environments.

[0027] This invention offers superior signal quality, supports high-precision measurements, and generates a uniform signal close to an ideal sine wave by forming an amplitude-transmitting surface through a moving disk and a mask plate, thereby reducing waveform distortion and noise interference. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the angular displacement detection device according to Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the specific structure of the light-transmitting surface of the mask plate in Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram of the light-transmitting surface structure of the moving disk in Embodiment 1 of the present invention;

[0032] Figure 4 This is a schematic diagram of the phase of the amplitude-transmitting surface in Embodiment 1 of the present invention;

[0033] Figure 5 This is a schematic diagram of the distribution of the photodetector elements in Embodiment 1 of the present invention;

[0034] Figure 6 This is a schematic diagram of the signal processing principle of Embodiment 1 of the present invention;

[0035] Figure 7 This is a schematic diagram of the spectrum comparison of single-field scanning difference frequency traveling wave of the present invention;

[0036] Figure 8 This is a schematic diagram comparing the waveforms of a single-field scanning difference frequency traveling wave according to the present invention;

[0037] Figure 9 This is a schematic diagram of the angular displacement detection device according to Embodiment 2 of the present invention;

[0038] Figure 10 This is a schematic diagram of the cylindrical reflector structure according to Embodiment 2 of the present invention;

[0039] Figure 11 This is a schematic diagram of the cylindrical reflective grating and mask plate in Embodiment 2 of the present invention;

[0040] Figure 12 This is a schematic diagram of the phase of the amplitude-transmitting surface in Embodiment 2 of the present invention;

[0041] Figure 13 This is a schematic diagram of the distribution of the photodetector elements in Embodiment 2 of the present invention.

[0042] In the diagram: 1. Light source; 2. Mask; 3. Moving disk; 4. Photodetector;

[0043] 31. First group of amplitude-transmitting surfaces; 32. Second group of amplitude-transmitting surfaces; 33. Third group of amplitude-transmitting surfaces; 34. Fourth group of amplitude-transmitting surfaces;

[0044] 41. First photodetector element; 42. Second photodetector element; 43. Third photodetector element; 44. Fourth photodetector element. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0046] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0047] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0048] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0049] Example 1

[0050] A light source component, used as the output of a light source;

[0051] Beam adjustment component, used to modulate the light emitted by the light source component and input it into the double cosine structure component;

[0052] A double cosine structure is used to input the beam output from the beam adjustment component into the photoelectric detector.

[0053] The photoelectric detector is used to receive the light intensity modulation signal from the double cosine structure and convert it into an electrical signal output.

[0054] Example 2

[0055] Based on the above embodiment one, the following is disclosed:

[0056] Reference Figures 1-8 A grid angle displacement measuring device for single-field scanning, comprising:

[0057] The light source is a light source body 1, which is used as a light source output to realize that the output beam is incident on the moving disk 2, and a sinusoidal excitation alternating current is passed through it. The beam is incident perpendicularly to the moving disk 2 and covers the light-transmitting surface of the mask plate 3.

[0058] The beam adjustment component is a movable disk 2, mounted on top of the light source 1. The movable disk 2 is made of a material with high light transmittance and low thermal expansion coefficient, such as quartz glass. It is ring-shaped and rotates along axis A. On the inner side of the ring, there are fan-shaped light-transmitting surfaces evenly arranged in a circle. The movable disk 2 has fan-shaped light-transmitting surfaces symmetrically centered on axis l along the circumferential direction. The radial height H of the fan-shaped light-transmitting surfaces corresponds to the distribution period P along the circumferential direction. bs The light intensity of the two incident beams is configured to limit the movement disk;

[0059] The double cosine structure is a mask plate 3, which is mounted on the top of the moving disk 2. The mask plate 3 is engraved with double cosine light-transmitting surfaces arranged in a uniform and closely spaced circle. The radial height h of the double cosine light-transmitting surfaces is related to the second period P. zsIt is used to generate a continuously changing light intensity modulation signal during the rotation of the moving disk 2, and to form a corresponding relationship with the spatial modulation frequency of the light-transmitting surface of the moving disk 2;

[0060] First cycle of the translucent surface of the moving plate 2 With the second cycle of the light-transmitting surface of the mask plate 3 The following conditions must be met:

[0061] ;

[0062] ;

[0063] In the third period of the amplitude-transmitting surface P zf Within, n sets of continuous amplitude-transmitting surfaces are formed, and the period of each set of transmitting surfaces satisfies the following condition:

[0064] ;

[0065] like Figure 2 As shown, the light-transmitting surface of mask plate 3 adopts a double cosine structure design. This double cosine light-transmitting surface is mainly composed of two identical half-period cosine line segments and circular arcs l1 and l2. The circular arcs l1 and l2 are both centered on axis A. The central angle θ corresponding to the starting point to the ending point of the double cosine light-transmitting surface is... zs The angle is 3.2°, the radial height h is 1 mm, and the second period P zs (3.2°) arrangement;

[0066] Moving plate 2, as Figure 3 The diagram shows a composition consisting of fan-shaped light-transmitting surfaces, where each fan-shaped light-transmitting surface corresponds to an angle θ. bs (Value taken as 1.5° here), radial height H is 5mm, and the first cycle P bs (Value 3° here) Arranged along the circumference. The relationship between the light-transmitting surface of mask 3 and the moving disk 2 satisfies P. zs ≠P bs H > h, forming as follows Figure 4 The third period shown is P zf A transmissive surface with a radial height h (5mm).

[0067] The moving disk 2 and the mask plate 3 are modulated to form a radial height h, and the third period is P. zf The amplitude of the light-transmitting surface, the period P zf The conditions are as follows:

[0068]

[0069] This design allows for a single P zf It becomes possible to divide the period into multiple groups of amplitude-transmitting surfaces, and each group of signals naturally carries a fixed phase difference that increases sequentially. Here, P zf The value is 48°.

[0070] Furthermore, the amplitude-transmitting surface is divided into four closely connected groups of amplitude-transmitting surfaces 31, 32, 33, and 34, each with a phase difference of 90°. The period of each group of amplitude-transmitting surfaces is 1 / 4. .

[0071] The light-transmitting surface of the moving disk 2 has at least a period equal to that of the light-transmitting surface of the mask 3 within the scanning cycle, as expressed below:

[0072] ;

[0073] The photoelectric detection element is a photoelectric detector 4, and the mask plate 3 overlaps and intersects with the moving disk 2, along the circumferential direction at a distance of 1 / nP. sd n sets of amplitude light-transmitting surfaces are periodically formed, and corresponding n sets of photodetector 4 elements are arranged above them. The photodetector 4 is installed on the top of the mask plate 3 to receive the light signal formed by the mask plate 3 and the moving disk 2, and convert it into an electrical signal output. Then, it simultaneously receives all the light flux of the n sets of amplitude light-transmitting surfaces and generates an incremental signal with a phase increasing by 360° / n.

[0074] The photodetector 4 is equipped with four photodetector elements. The first photodetector element 41 corresponds to the first group of amplitude-transmitting surfaces 31. The second photodetector element 42 corresponds to the second group of amplitude-transmitting surfaces 32. The third photodetector element 43 corresponds to the third group of amplitude-transmitting surfaces 33. The fourth photodetector element 44 corresponds to the fourth group of amplitude-transmitting surfaces 34.

[0075] The sensing area of ​​the photoelectric detection element should meet the following requirements:

[0076] When an excitation alternating current is applied to the light source, without modulation by the moving disk 2, the four sets of photodetector elements (first photodetector element 41, second photodetector element 42, third photodetector element 43, and fourth photodetector element 44) sequentially generate incremental signals with a phase difference of 90°. After photoelectric conversion, the four sets of photocurrents can be expressed as:

[0077]

[0078] in, The peak value of the sinusoidal excitation current; frequency. Angular frequency . This represents the light-transmitting area of ​​the first amplitude-transmitting surface 31 at a certain moment. This represents the light-transmitting area of ​​the second amplitude transmission surface 32 at a certain moment; This represents the light-transmitting area of ​​the third amplitude transmission surface 33 at a certain moment; This represents the light-transmitting area of ​​the fourth amplitude light-transmitting surface 34 at a certain moment.

[0079] When the moving disk 2 rotates around axis A, the light-transmitting area of ​​the four sets of amplitude-transmitting surfaces changes periodically, resulting in a change in the total photocurrent I obtained on the photodetector. φ The same periodic changes also occur. Specifically, when the moving disk rotates clockwise, the light-transmitting area of ​​the first group of amplitude light-transmitting surfaces 31 increases, the light-transmitting area of ​​the second group of amplitude light-transmitting surfaces 32 first increases and then decreases, the light-transmitting area of ​​the third group of amplitude light-transmitting surfaces 33 decreases, and the light-transmitting area of ​​the fourth group of amplitude light-transmitting surfaces 34 first decreases and then increases. Among them, the changes in the light-transmitting area of ​​the first group of amplitude-transmitting surfaces 31 and the third group of amplitude-transmitting surfaces 33 are completely opposite; the changes in the light-transmitting area of ​​the second group of amplitude-transmitting surfaces 32 and the fourth group of amplitude-transmitting surfaces 34 are completely opposite; the maximum value of the light-transmitting area of ​​the second group of amplitude-transmitting surfaces 32 is 90° out of phase with the maximum value of the light-transmitting area of ​​the first group of amplitude-transmitting surfaces 31; the maximum value of the light-transmitting area of ​​the third group of amplitude-transmitting surfaces 33 is 90° out of phase with the maximum value of the light-transmitting area of ​​the second group of amplitude-transmitting surfaces 32; and the maximum value of the light-transmitting area of ​​the fourth group of light-transmitting surfaces 34 is 90° out of phase with the maximum value of the light-transmitting area of ​​the third group of amplitude-transmitting surfaces 33.

[0080] The first photocurrent signal I1 and the third photocurrent signal I3 are amplified and then input into the first differential amplifier module, which outputs the first voltage signal U differentially. 13 The second photocurrent signal I2 and the fourth photocurrent signal I4 are amplified and then input to the second differential amplifier module, which outputs a second voltage signal U. 24 The FPGA adjusts the digital potentiometer to achieve amplitude matching, thus controlling the U... 13 The third voltage signal U is obtained by phase shifting it by 90° using a differential amplifier. 13’ ;Change U 13’ with U 24 The input is to the third differential amplifier module, which ultimately outputs a traveling wave signal U. o Its fundamental expression is: ;

[0081] Where: K s K is the optical intensity coupling coefficient. f α is the photocurrent amplification factor, α is the relative angular displacement between the moving disk and the mask, and θ is the angle corresponding to the fan-shaped light-transmitting surface of the moving disk (taken as 1.5° here).

[0082] After filtering and signal conditioning, the electrical signal is converted into a phase-coded traveling wave signal U whose phase varies with angular displacement. o like Figure 6 As shown, the phase-coded traveling wave signal U o A reference signal U with the same frequency and fixed phaser The signal is synchronously fed into the waveform shaping circuit and converted into a standard square wave signal that retains phase information. Subsequently, the phase difference detection circuit, in conjunction with a high-precision clock signal, quantizes and counts the phase difference between the two square wave signals. The microprocessor performs a conversion based on the calibration relationship between the counting result and the angular displacement, thereby obtaining the measured angular displacement value of the moving disk 2 relative to the mask plate 3.

[0083] Simulation results show that, Figure 7 and Figure 8 As shown, under the same periodic mismatch conditions, the difference frequency traveling wave signal formed by the traditional fan-shaped light-transmitting structure still contains obvious second and higher order harmonic components in addition to the fundamental wave. However, after adopting the double cosine continuous light-transmitting structure, the spectrum of the difference frequency traveling wave is mainly concentrated at the fundamental frequency, the amplitude of higher order harmonics is significantly reduced, and the signal waveform is closer to the ideal sine form. This effectively improves the purity and phase stability of the traveling wave, providing a more stable and reliable signal foundation for high-precision angular displacement measurement.

[0084] Example 3

[0085] Based on the above embodiment one, another solution different from embodiment two is disclosed:

[0086] Reference Figures 9-13 A single-field scanning grating angle displacement measuring device and a cylindrical reflective grating angle displacement sensor, the principle of which is the same as that in Embodiment 1:

[0087] It includes a light source 1 as a light source component, a cylindrical reflector as a beam adjustment component, a mask 3 as a double cosine structure component, and a photodetector 4 as a photoelectric detection component;

[0088] An excitation alternating current is passed through the light source 1, and after modulation, the output beam illuminates the surface of the cylindrical reflector at a preset incident angle. The modulated beam from the cylindrical reflector continues to be incident on a mask plate 3 at a fixed position. Under the action of the spatial periodic structure of the cylindrical reflector, the change in the light field is converted into a light intensity modulation signal with periodic characteristics that varies with angular displacement. Finally, it is received by the photodetector 4 and converted into an electrical signal for output. The cylindrical reflector rotates along the axial direction A, and its outer surface is provided with a periodically distributed stripe structure. The radius structure of the cylindrical reflector is as follows: Figure 10 As shown, R is 3.82 mm, the axis height H is 6 mm, and the grid line pitch angle θ is... bs The angle is 1.5°, corresponding to a grating line arc length pitch l of 0.1 mm. The stripe structure extends continuously in the circumferential direction, forming a cylindrical periodic optical modulation structure.

[0089] The phase relationship between the light reflected from the cylindrical surface and the mask 3 is shown in the figure below. Figure 11 As shown, light is reflected by the cylindrical surface, forming a radial height H of 6 mm and a width D of 0.1 mm, with a period P.bs (The value here is 0.2mm) The grid stripes are distributed, and the mask plate 3 adopts a double cosine structure design. This double cosine light-transmitting surface is mainly composed of two identical half-period cosine line segments and straight lines l1 and l2. The width d corresponding to the starting point to the ending point is 0.212mm, the radial height h is 0.4mm, and it is arranged with a period P. zs (The value here is 0.212mm) Arranged, the two grid lines satisfy P zs ≠P bs H > h. When the incident beam passes through the reflected perpendicular incident mask 3, it is constructed according to the following relationship: Figure 12 The period shown is P zf (3.533mm), with a radial height of h (0.4mm) and an amplitude of light transmission surface;

[0090] Furthermore, in the period P of the amplitude-transmitting surface zf The inner part is further divided into a first group of amplitude-transmitting surfaces 31, a second group of amplitude-transmitting surfaces 32, a third group of amplitude-transmitting surfaces 33, and a fourth group of amplitude-transmitting surfaces 34; corresponding to 0°, 90°, 180°, and 270° phases, respectively. The photodetector 4 is equipped with photodetector elements corresponding to the above four groups of amplitude-transmitting surfaces, and their structural distribution is as follows. Figure 13 As shown, the first photodetector element 41 corresponds to the first group of amplitude-transmitting surfaces 31; the second photodetector element 42 corresponds to the second group of amplitude-transmitting surfaces 32; the third photodetector element 43 corresponds to the third group of amplitude-transmitting surfaces 33; and the fourth photodetector element 44 corresponds to the fourth group of amplitude-transmitting surfaces 34.

[0091] When an excitation alternating current is applied to the light source 1, without modulation by a moving disk, the four sets of photoelectric detection elements (first photoelectric detector element 41, second photoelectric detector element 42, third photoelectric detector element 43, and fourth photoelectric detector element 44) sequentially generate incremental signals with a phase difference of 90°, which are then converted into electrical signals for output after photoelectric conversion. The expression of its parameters is completely consistent with that in Example 1.

[0092] When the cylindrical reflector rotates about axis A, the light-transmitting areas of the four sets of amplitude-transmitting surfaces change periodically, consistent with Example 1, resulting in a change in the total photocurrent I obtained on photodetector 4. φ The same periodic change also occurs. After conversion by a current-to-voltage amplifier circuit and capacitor isolation, the desired traveling wave signal is obtained, and its fundamental expression is: ;

[0093] In the formula: α is the angular displacement of the cylindrical reflector relative to the mask plate 3; θ is the angle corresponding to the fan-shaped light-transmitting surface of the moving disk (taken as 1.5° here). The definitions of the other parameters are the same as in Example 1.

[0094] After filtering and conditioning, the electrical signal is converted into a phase-coded traveling wave signal U.o , and reference signal U r The waveform is synchronously fed into a waveform shaping circuit and converted into a standard square wave. Subsequently, the phase difference detection circuit quantizes and counts the waveform, and the microprocessor performs calculations to finally obtain the angular displacement measurement value of the cylindrical reflector relative to the mask plate 3.

[0095] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A grating angle displacement measuring device for single-field scanning, characterized in that, include: The light source (1) is used as a light source output to realize the output beam incident on the moving disk (2). The mask plate (3) is fixedly installed on the back of the moving disk (2). The mask plate (3) has double cosine light-transmitting surfaces arranged in a uniform and dense circle. The photodetector (4) is installed on the back of the mask plate (3) to receive the light signal formed by the mask plate (3) and the moving disk (2) and convert it into an electrical signal output.

2. The grating angle displacement measuring device for single-field scanning according to claim 1, characterized in that, The moving disk (2) is engraved with a fan-shaped light-transmitting surface along the circumferential direction with the axis l as the center of symmetry. The radial height H of the fan-shaped light-transmitting surface is related to the first period P of the distribution along the circumferential direction. bs The light intensity of the incident beam is controlled by the limiting disk (2).

3. The grating angle displacement measuring device for single-field scanning according to claim 2, characterized in that, The radial height h of the bicosine light-transmitting surface and the second period P zs Used to generate a continuously changing light intensity control signal during the rotation of the moving disk (2).

4. The grating angle displacement measuring device for single-field scanning according to claim 3, characterized in that, The first cycle of the light-transmitting surface of the moving disk (2) The second period of the light-transmitting surface of the mask plate (3) The following conditions must be met: ； 。 5. The grating angle displacement measuring device for single-field scanning according to claim 4, characterized in that, The moving disk (2) and the mask plate (3) are modulated to form a radial height h, and the third period is P. zf The amplitude of the light-transmitting surface, the third period P zf The conditions are as follows: 。 6. The grating angle displacement measuring device for single-field scanning according to claim 5, characterized in that, The light-transmitting surface of the moving disk (2) has at least a period equal to that of the light-transmitting surface of the mask plate (3) within the scanning cycle, as expressed below: 。 7. The grating angle displacement measuring device for single-field scanning according to claim 5, characterized in that, In the third period of the amplitude-transmitting surface P zf Within, n sets of continuous amplitude-transmitting surfaces are formed, and the period of each set of transmitting surfaces satisfies the following condition: 。 8. A grating angle displacement measuring device for single-field scanning according to any one of claims 1-7, characterized in that, The mask plate (3) overlaps and intersects with the moving disk (2) along the circumferential direction at a distance of 1 / nP. sd n sets of amplitude-transmitting surfaces are periodically formed, and corresponding n sets of photodetector (4) elements are arranged above them. They simultaneously receive all the light flux of the n sets of amplitude-transmitting surfaces and generate incremental signals with phases increasing by 360° / n.

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