Method for manufacturing a vibrating member

Abstract

One aspect of the present invention relates to a method for manufacturing a vibrating member having structural characteristics of predetermined values. [Solution] This method includes a calculation step (31) in which the values ​​of the structural characteristics of the vibrating member (2) formed on the plates (1a, 1b) are calculated from a generation sub-step (39), in which the generation sub-step generates these values ​​based on a prediction algorithm used by a computer (8), and processes at least one characteristic of the identified resonant frequency of the vibrating member (2) when exposed to vibration excitation in an optical measurement sub-step (38), and a modification step (42) in which the dimensions of the vibrating member (2) are corrected based on a dimensional correction calculated based on the calculated structural characteristics.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing parts for the watch industry. More particularly, the present invention relates to a method for manufacturing a vibrating member having structural characteristics such as rigidity, which is a predetermined value.

Background Art

[0002] In the prior art, it is common to use a method of manufacturing a vibrating member on a plate. In this method, etching techniques such as laser engraving, plasma engraving, deep reactive ion etching (DRIE), or wet etching are used.

[0003] However, it has been found that when such a method is used, geometric dissipation usually occurs between vibrating members formed in the same pattern on the same plate.

[0004] In order to improve these drawbacks, solutions have been proposed in the prior art, particularly in European Patent Publication Nos. 3181938 (Patent Document 1) and 3181939 (Patent Document 2), which describe a method for manufacturing a hairspring.

[0005] In European Patent Publication No. 3181938 (Patent Document 1), the manufacturing method includes: a) forming a hairspring with dimensions larger than those required to obtain a hairspring having a predetermined rigidity; b) determining the rigidity of the hairspring formed in step a) by measuring the frequency of the hairspring combined with a template having a predetermined inertia; c) calculating the thickness of the material to be removed to obtain a hairspring having a predetermined rigidity; and d) removing the calculated thickness of the material from the hairspring formed in step a). Steps b), c), and d) can be repeated to further improve dimensional quality.

[0006] European Patent Publication No. 3181939 (Patent Document 2) describes a manufacturing method comprising: a) forming a hairspring with dimensions smaller than those required to obtain a hairspring with predetermined rigidity; b) determining the rigidity of the hairspring formed in step a) by measuring the frequency of the hairspring coupled to a balance wheel having predetermined inertia; c) calculating the thickness that is lacking to obtain a hairspring with predetermined rigidity; and d) modifying the hairspring formed in step a) to compensate for the lack of material thickness, wherein steps b), c), and d) can be repeated to further improve dimensional quality.

[0007] This method can be improved, especially to reduce plate contamination that may occur during measurement.

[0008] In this situation, it is clear that we need to find solutions that will lead to such improvements. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] European Patent Publication No. 3181938 [Patent Document 2] European Patent Publication No. 3181939 [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention aims to provide a method for manufacturing a vibrating member that satisfies the above-mentioned needs. [Means for solving the problem]

[0011] The present invention is a method for manufacturing a vibrating member having structural characteristics of predetermined values, wherein the method is a) A step of forming the vibrating member on a plate according to dimensions different from the dimensions necessary to obtain the vibrating member having structural characteristics of a predetermined value, b) A step of calculating the structural characteristics of the vibrating member of the plate from the generation sub-step, wherein the generation sub-step generates this value based on a prediction algorithm used by a computer, and processes at least one characteristic of the resonant frequency identified for the vibrating member when exposed to vibration excitation in the optical measurement sub-step, d) A step of calculating the dimensional correction applied to the formed vibrating member based on the calculated structural characteristic values, e) A step of modifying the dimensions of the formed vibrating member based on a calculated dimensional correction in order to obtain a vibrating member with dimensions smaller than the dimensions required to obtain the vibrating member having structural characteristics of a predetermined value. Regarding methods including

[0012] In other embodiments, - The calculation process includes a placement sub-process in which the vibrating members included in the plate are placed in a device that calculates the structural characteristics of the vibrating members. - The arrangement sub-step includes a determination step of determining a measurement portion of the vibrating member that can exhibit a significant vibration response when the vibrating member is exposed to vibration excitation, - The placement sub-step includes a positioning step of positioning the vibrating member in the optical measurement module, particularly between the laser source and the photodiode optical sensor. - The placement sub-step includes a positioning step of positioning the vibrating member relative to the generating module, - The calculation process includes a configuration sub-process that involves focusing a circular ray that can be emitted from a laser source onto the edge of a vibrating member. - The calculation process includes an application sub-process in which time-varying vibration excitation is applied to the vibrating member. -This sub-step involves inducing this vibration excitation and applying an excitation signal with sufficient amplitude to the vibrating member for accurate detection and measurement by the optical measurement module. -In the optical measurement sub-process, a computer connected to the optical measurement module calculates at least one characteristic of the resonant frequency based on data including the amplitude and vibration phase spectrum relating to the displacement of the blade of the vibrating member according to the excitation frequency. - The calculation step includes a calculation sub-step that, based on this value of the calculated structural properties, calculates the thickness of material to be added to or removed from at least one dimension of the vibrating member formed in the forming step, thereby obtaining a vibrating member having a predetermined value of structural properties.

[0013] Other features and advantages of the present invention will become even clearer by reading the following description of specific embodiments of the invention, which are presented as illustrative and non-limiting examples, and by referring to the accompanying drawings. [Brief explanation of the drawing]

[0014] [Figure 1] This is a flowchart relating to a method for manufacturing a vibrating member having predetermined structural characteristics according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of a plate according to an embodiment of the present invention, and in particular, a diagram that includes a set of vibrating members, all of which are simultaneously formed within the plate by engraving. [Figure 3] This is a schematic diagram of another plate according to an embodiment of the present invention, and in particular, a diagram that includes a set of vibrating members, all of which are simultaneously formed within this plate by engraving. [Figure 4] An embodiment of the present invention is a schematic diagram of a first modified example of an apparatus for calculating the structural characteristics of a vibrating member, the apparatus comprising an element that generates vibration excitation in the body of the element, which is in mechanical contact with a portion of a plate having the mounting end of the vibrating member, and a module for optically measuring at least one characteristic of the specified resonant frequency of the vibrating member. [Figure 5] This is a schematic diagram of a second modified example of an apparatus for calculating the structural characteristics of a vibrating member according to an embodiment of the present invention, the apparatus comprising an element that generates vibration excitation in the body of the element, which is in mechanical contact with a portion of a plate having the mounting end of the vibrating member, and a module for optically measuring at least one characteristic of the identified resonant frequency of the vibrating member. [Figure 6] This is a schematic diagram of an enlarged view of portion A of the plate shown in Figure 3, which includes a vibrating member according to an embodiment of the present invention. [Figure 7] A schematic diagram of a third modification of a calculation device including an element that generates this vibration excitation in a main body of a vibration member that is not in mechanical contact with a plate portion having an attachment end of the vibration member according to an embodiment of the present invention, and a module that optically measures at least one characteristic of a specific resonance frequency of the vibration member. [Figure 8] A schematic diagram of a module that optically measures at least one specification of a specific resonance frequency of a vibration member according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0015] FIG. 1 is a schematic diagram of a method for manufacturing a vibration member 2 having structural characteristics of a predetermined value. This method aims to maintain extremely high dimensional accuracy of the manufactured vibration member 2 and, as a result, to ensure more accurately the structural characteristics of this vibration member 2.

[0016] In this method, the vibration member 2 is configured to vibrate at a stable frequency even when specific parameters related particularly to the setting process and the manufacturing process change. This stable frequency changes according to at least one structural characteristic. Such structural characteristics are determined particularly by inherent vibration characteristics such as resonance frequencies. Each resonance frequency of the vibration member 2 exposed to an excitation force is a frequency at which the maximum value of the displacement amplitude in the plane of the plates 1a, 1b at a specific portion of this vibration member 2 can be measured. In other words, when the vibration member 2 is excited by an excitation source with a time-varying frequency, the displacement amplitude at this portion follows an ascending gradient before this resonance frequency and then follows a descending gradient. Typically, in such a test, when the displacement amplitude is recorded in relation to the excitation frequency, a displacement amplitude peak or resonance peak related to or characteristic of the resonance frequency is shown.

[0017] In this regard, such structural characteristics may be rigidity, blade thickness, or even elastic couple force.

[0018] It should be noted that in one embodiment, the vibrating member 2 may be a beam, a measuring structure, a test piece, or even a silicon hairspring designed to be fitted to the balance wheel of a mechanical watch movement, or a mechanical resonator specifically designed to be fitted to a watch adjustment mechanism.

[0019] In Figures 2 and 3, a set of vibrating members 2 is contained within plates 1a and 1b, and each of these vibrating members 2 is generally beam-shaped. In this set, each vibrating member 2 includes an elastically flexible portion. As previously mentioned, this member may be a hairspring of a watch, in which case the hairspring includes an elastically flexible strand, one end of which is connected to a hairspring ball, and which is wound spirally to form a series of continuous windings, and the end of the hairspring ball has a mounting portion designed to be attached to a balance bridge, for example, fixed by a hairspring holder.

[0020] Referring to Figure 1, such a method includes a forming step 30 in which a set of vibrating members is formed on plates 1a and 1b. In this set, each vibrating member 2 has dimensions different from the dimensions of the vibrating member 2 to be manufactured and has structural characteristics of predetermined values. Referring to Figure 3, plate 1b has through holes 20 formed in a portion 16 of plate 1b, and this portion 16 has mounting ends 5a for attaching the vibrating members 2 to plate 1b.

[0021] In this step 30, the vibrating members 2 are preferably formed simultaneously on the material plates 1a and 1b. Each vibrating member 2 can be formed on plates 1a and 1b by engraving, for example, deep reactive ion etching, laser engraving, chemical engraving, or engraving using a focused ion beam. It should be noted that it is preferable that the vibrating members 2 in the set have similar shapes on plates 1a and 1b.

[0022] The vibrating member 2 formed on plates 1a and 1b has at least one blade 3. Referring to Figure 8, this blade 3 has a cross-section 4 with dimensions E and H, and if such a blade 3 is polygonal, the features of this cross-section 4 are that the height is H and the thickness is E. These dimensions are different from the corresponding dimensions of the vibrating member 2 to be acquired, which has predetermined structural characteristics. In other words, the cross-section 4 of the blade 3 of this vibrating member 2 may have dimensions E and H that are larger or smaller than the corresponding dimensions of the cross-section 4 of the blade 3 of the vibrating member 2 to be acquired, which has predetermined structural characteristics.

[0023] Plates 1a, 1b, and blade 3. The vibrating member 2 has a mounting end 5a and at least one free end 5b. Each vibrating member 2 is housed in a through-opening 6 provided in plates 1a, 1b. This opening 6 forms a space in which the vibrating member 2 can freely perform controlled mechanical vibration motion within the plane of plates 1a, 1b.

[0024] In the context of this method, plates 1a and 1b are preferably made of doped silicon or undoped silicon. This silicon may be single-crystal silicon, polycrystalline silicon, or amorphous silicon. Furthermore, this silicon may have {1,1,1}, {-1,1,1}, {1,-1,1}, or {-1,-1,1} orientations. Alternatively, plates 1a and 1b may be made from glass, ceramic, carbon nanotubes, quartz, metal, or alloy.

[0025] Next, this method includes a calculation step 31 for calculating the structural characteristics of the vibrating members 2 formed on plates 1a and 1b. In this step 31, this method uses a device 7 for calculating these values.

[0026] This calculation device 7 is non-limiting and non-exclusive, - Computer 8, - Modules 9a, 9b, and 9c that generate time-varying vibration excitations in the main body of the vibrating member 2. - An optical measurement module for measuring at least one characteristic of the resonant frequency of an identified vibrating member 2, comprising a laser source 12 and a photodiode light sensor 13, It is equipped with.

[0027] The computer 8 within this calculation device is connected to the generation modules 9a, 9b, 9c and the optical measurement module. The computer 8 comprises at least one processor and memory element. The computer 8 can execute computer programs 8 designed, for example, to drive / test the drive module and the measurement module, and can also execute instructions to perform computational / processing operations that execute at least one prediction algorithm stored in the memory element. This algorithm may include machine learning algorithms and / or mathematical formulas. This algorithm can execute a prediction model or simulation model that enables the calculation of structural property values ​​of the vibrating members 2 contained in plates 1a, 1b based on measurements of at least one characteristic of the identified resonant frequency of the vibrating member 2 exposed to vibration excitation.

[0028] It should also be noted that, as a general principle, the predictive model executed by this algorithm is configured to take resonant frequency characteristics as input and provide structural characteristics as output.

[0029] In this device 7, the generating modules 9a, 9b, and 9c can transmit vibration excitation to the main body of the vibrating member 2 when they are in mechanical contact with the portion 16 of the plates 1a and 1b having the mounting end 5a of the vibrating member 2, or ideally when they are not in contact with this portion 16.

[0030] When the generating modules 9a and 9b are in mechanical contact with the plates 1a and 1b to generate vibration excitations in the body of the vibrating member 2, the generating modules are equipped with a mechanism 15 for transmitting these vibration excitations, which may be a needle-shaped mechanical contact end 11 in the first modification shown in Figure 4, or a hemispherical or conical contact end 11 in the second modification shown in Figures 3, 5, and 6. Such ends are preferably made of a material such as ceramic to minimize potential damage to the plates 1a and 1b. The transmission mechanism 15 is configured to generate vibration excitations in the vibrating member 2, causing the body of the vibrating member to vibrate mechanically around its stable equilibrium position. Note that the transmission mechanism 15 can generate such vibration excitations using piezoelectric technology.

[0031] If the generating module 9c is not in mechanical contact with plates 1a and 1b, the generating module is configured to generate airflow 17 toward the vibrating member 2, causing the body of the vibrating member 2 to vibrate mechanically around its stable equilibrium position.

[0032] This calculation step 31 includes a placement sub-step 32 in which the blades 3 of the vibrating members 2 contained in plates 1a and 1b are placed in the calculation device 7. In this sub-step 32, the blades 3 of the vibrating members 2 are placed for both the optical measurement module 10 and the generation modules 9a, 9b, and 9c.

[0033] This arrangement sub-step 32 includes a determination step 33 to determine the measurement portion 20 of the blade 3 of the vibrating member 2. In this step 33, the displacement of the vibration wave occurring in the body of the blade 3 is measured several times at various parts of the blade 3 to identify the measurement portion 20 that is likely to show a significant vibration response when the body of the blade 3 is exposed to vibration excitation. In fact, the reason such a step 33 is necessary is that when the blade 3 is exposed to vibration excitation, especially when the frequency changes over time, the blade may contain portions where the amplitude of vibration displacement is low or zero. In this embodiment, this measurement portion 20 is located at one-third of the body of the blade 3, including the free end 5b of the blade 3. When measuring a non-linear adjustment mechanism, it is important to avoid measurements at vibration nodes within the structure.

[0034] Subsequently, this placement sub-step 32 includes a positioning step 34 in which the measuring portion 20 of the blade 3 is positioned in the optical measuring module 10, specifically between the laser source 12 and the photodiode optical sensor 13. Referring here to Figures 4, 5, 7, and 8, the laser source 12 is positioned facing the upper surface 18a of the blade 3, and the photodiode optical sensor 13 is positioned facing the lower surface 18b of the blade 3. In this configuration, the laser source 12 is collinear with the photodiode optical sensor 13.

[0035] This sub-step 32 includes a positioning step 35 in which the blades 3 of the vibrating member 2 are positioned relative to the generating modules 9a, 9b, and 9c. In fact, when the transmission mechanism 15 within these generating modules 9a and 9b is in mechanical contact with the plates 1a and 1b, its contact end 11 is positioned so as to be in mechanical contact with the portion of these plates 1a and 1b that includes the mounting end 5a of the vibrating member 2.

[0036] In this case, the tip of the first modified form of the transmission mechanism 15 is positioned in one of the sub-regions 16 defined on both sides of the longitudinal axis of the blade 3, so that the boundary contact between the surface of this region and the surface of the tip is not located on or very close to this axis.

[0037] In this second modification of the transmission mechanism 15, the transmission mechanism is positioned in a through hole 19 located in a portion 16 including the mounting end 5a of the vibrating member 2. In this position, the end of the generating mechanism 9b is in contact with the surface of the peripheral wall of the through hole 19.

[0038] In these first and second modifications, the mechanism 15 is oriented toward the through-opening 6 containing the vibrating member 2, and this orientation forms an acute angle α with the longitudinal axis B of the blade 3 on both sides of this axis B. Such an angle α is 30 degrees or more, preferably 30 to 50 degrees, and preferably 45 degrees.

[0039] As mentioned above, the transmission mechanism 15 within the generation module 9c may be non-contact. In this configuration, the transmission mechanism 15 is positioned relative to the blade 3 to diffuse the airflow 17 toward the measurement portion of the blade 3 that is exposed to the light beam 14 emitted from the laser source 12 of the optical measurement module 10.

[0040] This step 31 includes a configuration sub-step 36 that constructs the circular ray 14 emitted from the laser source 12. More specifically, in this sub-step 36, as shown in Figure 8, the ray 14 is focused on the edge 21 of the blade 3, particularly the angular edge located on the measuring portion 20. Under these conditions, the diameter of the ray 14 is configured to take into account the dimensions of the measuring portion 20 of the blade 3. Thus, this sub-step 36 helps to improve the modulation of the optical output of this laser ray 14 that the photodiode optical sensor 13 is expected to receive due to the amplitude of the vibration of the blade 3. In other words, the focus of the circular ray is adjusted so that the amplitude of the vibration of the blade 3 on the planes of plates 1a and 1b does not exceed the radius of this ray.

[0041] Next, this calculation step 31 includes an application sub-step in which time-varying vibration excitation 37 is applied to the vibrating member 2. In this sub-step 37, the generation modules 9a, 9b, and 9c apply an excitation signal with an amplitude sufficient to induce this vibration excitation and to be accurately detected and measured by the optical measurement module 10 to the blade 3 of the vibrating member 2. These generation modules 9a, 9b, and 9c - A first mode that maintains the vibrational excitation at a single specific frequency, or - A second mode in which vibration excitation is applied to the body of blade 3 at a time-varying frequency that covers a predetermined frequency range (the entire frequency range can be scanned or covered at specific time intervals), - A third mode that alternates between this first mode and the second mode, or combines them in a continuous sequence. It is triggered by this.

[0042] Step 31 includes an optical measurement sub-step 38 for measuring at least one characteristic of the identified resonant frequency of the vibrating member 2 (such as the value of this resonant frequency). In this sub-step 38, the output of light received by the photodiode light sensor 13 is measured in order to estimate the vibration amplitude at the measurement portion 20 of the blade 3. Note that the output received by the light sensor 13 is maximum at the resonant frequency, as this amplitude is maximum at that frequency.

[0043] In this sub-step 38, a computer 8 connected to the laser source 12 and the photodiode optical sensor 13 calculates at least one characteristic of the resonant frequency based on data including the amplitude of the displacement of the blade 3 and the vibration phase spectrum depending on the excitation frequency. This data is generated by the computer 8 from a time-based recording of the vibration amplitude and phase resulting from the light ray 14 received by the optical sensor 13.

[0044] Once the aforementioned characteristics of the resonant frequency have been calculated, the calculation step 31 includes a generation sub-step 39 that generates values ​​for the structural characteristics of the vibrating member 2 contained in plates 1a and 1b. In this sub-step 39, the computer 8 calculates these structural characteristics based on the resonant frequency characteristics by executing a prediction algorithm.

[0045] Next, this method includes a calculation step 40 in which the dimensional correction to be applied to the vibrating member 2 is calculated based on the structural characteristic values ​​calculated for this vibrating member 2 included in plates 1a and 1b. In this step 40, the amount of dimensional correction to be applied to the vibrating member 2 is estimated.

[0046] To do this, the calculation step 40 includes a calculation sub-step 41 for obtaining a vibrating member 2 having a predetermined value of structural properties by calculating the thickness of material to add to or remove from at least one dimension of the vibrating member 2 formed in the forming step 30, based on this value of the calculated structural properties.

[0047] This dimensional correction is applied to at least one of the dimensions E and H of the vibrating member, i.e., -Blade 3 height H only, or -Only the thickness E of that blade 3, or -Both this height H and this thickness E This substantially corresponds to the thickness of the material removed or added to the vibrating member 2 in order to change the result.

[0048] This dimensional correction can be performed over one or more separate lengths of the blade 3 of the vibrating member 2 or over the entire length of the blade 3.

[0049] By calculating dimensional corrections, such sub-process 41 helps to shape the vibrating member 2, thereby giving the vibrating member 2 structural properties that are substantially similar to or similar to those of a predetermined value.

[0050] Next, this method includes a modification step 42 in which, in order to obtain a vibrating member 2 having structural characteristics of predetermined values, the dimensions E and H of the vibrating member 2 are modified based on dimensional corrections calculated.

[0051] In this case, if the dimensions E and H of the formed vibrating member 2 are larger than the dimensions required to obtain the vibrating member 2 to be manufactured, the step 42 includes a removal sub-step 43 in which material is removed based on a calculated thickness of material to be removed. This removal can be carried out using a process that oxidizes the vibrating member 2 and then deoxygenates it, a process known in the prior art. Such a sub-step 43 aims to reduce the dimensions of the cross-section 4 of the blade 3 of the vibrating member 2 over a specific length or the entire length of the blade 3.

[0052] If the dimensions E, H of the vibrating member 2 are smaller than the dimensions required to obtain the vibrating member 2 to be manufactured, the process 40 includes an additional sub-process 44 to add material according to the calculated thickness of the additional material to be added. This material can be added using methods known in the prior art, such as thermal oxidation, galvanic growth, physical vapor deposition, chemical vapor deposition, atomic layer deposition, or other additional processes. Such a sub-process 44 is intended to increase the dimensions E, H of the cross-section 4 of the blade 3 of the vibrating member 2 over a specific length or the entire length of the blade 3.

[0053] Therefore, this method makes it possible to correct dimensional errors in vibrating members manufactured using such methods that require photolithography and / or DRIE technology with high precision. [Explanation of symbols]

[0054] 1a, 1b Plates including at least one vibrating member 2. Vibrating Member 3. Blades of the vibrating member 4. The cross-section of the vibrating element blade has dimensions different from those corresponding to the cross-section of the hairspring to be manufactured. 5a Mounting end of the blade of the vibrating member 5b Free end of the blade of the vibrating member 6. Through-opening of the plate on which the vibrating member is located. 7. Apparatus for calculating the structural characteristics of a vibrating member. 8 Computers 9a, 9b, 9c Modules that generate time-varying vibration excitations in the main body of the vibrating member. 10. Module for optically measuring at least one characteristic of the identified resonant frequency of a vibrating member. 11 Mechanical contact ends of the generation module 12 Laser sources 13 Photodiode light sensor 14. Light beam from a laser source 15. Transmission mechanism of vibrational excitation 16 Plate portion having mounting end 17. Airflow from the generation module 18a Top surface of the blade 18b Underside of the blade 19 Through holes formed in the plate portion 20 Blade measuring section 21 Edge of the blade measuring section

Claims

1. A method for manufacturing a vibrating member (2) having structural characteristics of a predetermined value, wherein the method is: a) A step (30) of forming the vibrating member (2) on the plate (1a, 1b) in dimensions different from the dimensions required to obtain the vibrating member (2) having the structural characteristics of the predetermined value, b) A step (31) of calculating the structural characteristics of the vibrating members (2) of the plates (1a, 1b) from the generation sub-step (39), wherein the generation sub-step generates the values ​​based on a prediction algorithm used by a computer (8), and processes at least one characteristic of the resonant frequency identified for the vibrating members (2) when exposed to vibration excitation in the optical measurement sub-step (38), d) A step (40) of calculating the dimensional correction applied to the formed vibrating member (2) based on the calculated structural characteristic values, e) A step (42) to modify the dimensions of the formed vibrating member (2) based on the calculated dimensional correction in order to obtain the vibrating member (2) having dimensions smaller than the dimensions required to obtain the vibrating member (2) having the structural characteristics of the predetermined value; A method that includes this.

2. The method according to claim 1, wherein the calculation step (31) includes a placement sub-step (32) of placing the vibrating members (2) included in the plates (1a, 1b) into an apparatus (7) for calculating the structural characteristics of the vibrating members (2).

3. The method according to claim 2, wherein the arrangement sub-step (32) includes a determination step (33) for determining a measurement portion (20) of the vibrating member (2) that can exhibit a significant vibration response when the vibrating member (2) is exposed to vibration excitation.

4. The method according to claim 1, wherein the calculation step (31) includes a placement sub-step (32) in which the vibrating member (2) included in the plate (1a, 1b) is placed in an apparatus (7) for calculating the structural characteristics of the vibrating member (2), and the placement sub-step (32) includes a positioning step (34) in which the vibrating member (2) is positioned in an optical measurement module (10), particularly between the laser source (12) and the photodiode light sensor (13).

5. The method according to claim 1, wherein the calculation step (31) includes a placement sub-step (32) in which the vibrating members (2) included in the plates (1a, 1b) are placed in a device (7) for calculating the structural characteristics of the vibrating members (2), and the placement sub-step (32) includes a positioning step (35) in which the vibrating members (2) are positioned relative to the generating modules (9a, 9b, 9c).

6. The method according to claim 1, wherein the calculation step (31) includes a placement sub-step (32) of placing the vibrating member (2) included in the plates (1a, 1b) in an apparatus (7) for calculating the structural characteristics of the vibrating member (2), the placement sub-step (32) includes a positioning step (34) of positioning the vibrating member (2) in an optical measurement module (10), particularly between the laser source (12) and the photodiode light sensor (13), and the calculation step (31) includes a configuration sub-step (36) of forming a circular ray (14) that can be emitted from the laser source (12) by focusing it on the edge (21) of the vibrating member (2).

7. The method according to claim 1, wherein the calculation step (31) includes an application sub-step (37) in which time-varying vibration excitation is applied to the vibrating member (2).

8. The method according to claim 7, wherein the sub-step (37) involves applying an excitation signal to the vibrating member (2) with an amplitude sufficient to induce the vibration excitation and to be accurately detected and measured by the optical measurement module (10).

9. The method according to claim 1, wherein in the optical measurement sub-step (38), the computer (8) connected to the optical measurement module (10) calculates at least one characteristic of the resonant frequency based on data including amplitude and vibration phase spectra relating to the displacement of the blade (3) of the vibrating member (2) according to the excitation frequency.

10. The method according to claim 1, wherein the calculation step (40) includes a calculation sub-step (41) which calculates the thickness of material to be added to or removed from at least one dimension of the vibrating member (2) formed in the forming step (30) based on the calculated value of the structural characteristics, in order to obtain the vibrating member (2) having a predetermined value of structural characteristics.

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