Spectral black hole confocal measuring device and measuring method

Abstract

The application discloses a kind of spectral confocal measuring device and measuring method, by scientific and reasonable design by wide-spectrum light source, multiple-core optical fiber, confocal dispersion component and optical signal processing component constitute optical system, can obtain the part defocus light around confocal focus in optical system, further make optical signal processing component obtain the optical spectrum signal with certain width wave crest and middle with a sharp trough, according to the trough in the obtained optical spectrum signal and the wave crest value data on both sides processing and multiple calculation, according to the displacement relationship of the calculated value and the measured panel in unit time, then high efficiency accurate can be realized without contact to calculate the surface type or thickness of measured panel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of front optical detection, in particular to a spectral confocal measuring device and a measuring method. BACKGROUND

[0002] With the development of industry, the progress of technology and the improvement of process level, many similar mobile phone transparent panel production manufacturers have more and more demand for panel surface shape and thickness measurement, and the requirement for precision is higher and higher. For example, the production of mobile phone panel, the design is thinner and thinner, the straight screen transparent panel should meet the flatness requirement, and part of the curved transparent panel should meet the curved surface requirement, and at the same time, high measurement efficiency should be ensured. The demand for precision measurement is also huge in other industries with transparent panel demand, and the requirement is more complex. For this situation, the optical measurement sensor which can realize non-contact, fast measurement, high precision and low cost has become a popular choice.

[0003] At present, the most widely used measurement method in China is contact measurement, which is slow and easy to scratch the measured panel or leave fingerprints or foreign matter. For domestic non-contact optical measurement sensor, there are few types, the application is not wide, the cost is high and the precision is insufficient, and high-end non-contact optical measurement sensor is mainly designed and produced by foreign countries, and the introduction and purchase cost is high.

[0004] For the common confocal spectral detection method, sharp peak signal is obtained on the spectrum for analysis. In order to improve the measurement accuracy, the smaller the light spot is required in the existing confocal spectral system. Because a wide spectrum light source is needed, the size of the pinhole or optical fiber is usually as small as possible. After the size is reduced, the light spot effect is better, the spectral peak signal is sharper, the measurement signal is close to the single measured confocal focal length, so that the measurement value with higher precision is obtained. However, this will make it more difficult to couple light into the optical fiber or the light energy will be much weaker after the light source passes through the small hole, so that the reflected light signal of the measured panel surface is weaker. If the resolution is to be improved by using this detection method, the difficulty will increase, and the design and production cost will also increase. Moreover, after obtaining sharp peak signal, the peak width is smaller than the resolution sampling interval, and the measurement accuracy will also decrease.

[0005] Therefore, the present application is proposed to solve the above problems. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art, provide a spectral confocal measuring device and a measuring method, which can improve the problems of the prior art, increase the stability and precision of measurement, and have the characteristics of low cost.

[0007] The present application is realized by the following technical solutions:

[0008] A spectral black hole confocal measuring device, sequentially provided along an optical axis are:

[0009] a wide spectrum light source, a multi-core optical fiber 4 and a confocal dispersion assembly;

[0010] The wide spectrum light source is configured to provide and emit light beams of at least two different wavebands;

[0011] The multi-core optical fiber 4 has an incident end, a receiving end and a merging end, the incident end of the multi-core optical fiber 4 comprises a plurality of emitting cores, the receiving end of the multi-core optical fiber 4 comprises a receiving core, and the merging end 40 of the multi-core optical fiber 4 comprises the emitting cores of the incident end and the receiving core of the receiving end;

[0012] The emitting cores of the incident end of the multi-core optical fiber 4 are coupled to the wide spectrum light source, the merging end 40 of the multi-core optical fiber 4 is directed towards the confocal dispersion assembly, and the receiving end 44 of the multi-core optical fiber 4 is connected to an optical signal processing assembly 7;

[0013] The confocal dispersion assembly is configured to axially disperse and focus the light beams emitted by the merging end 40 of the multi-core optical fiber 4, and to collect and focus the reflected light from the corresponding surface of a measured panel 8 on the merging end 40 of the multi-core optical fiber 4;

[0014] The optical signal processing assembly 7 is configured to receive and process the optical signals transmitted by the receiving end 44 of the multi-core optical fiber 4.

[0015] The spectral black hole confocal measuring device as described above, the wide spectrum light source comprises a first light source 1 configured to provide and emit ultraviolet light, a second light source 2 configured to provide and emit visible light, and a third light source 3 configured to provide and emit infrared light; the incident end of the multi-core optical fiber 4 comprises a first branch end 41, a second branch end 42 and a third branch end 43 coupled to the first light source 1, the second light source 2 and the third light source 3, respectively.

[0016] The spectral black hole confocal measuring device as described above, the incident end of the multi-core optical fiber 4 has a core II, a core III, a core IV, a core V, a core VI and a core VII, the first branch end 41 has the core II and the core V, the second branch end 42 has the core III and the core VI, and the third branch end 43 has the core IV and the core VII; the receiving end 44 of the multi-core optical fiber 4 has a core I; the merging end 40 of the multi-core optical fiber 4 has the core I, the core II, the core III, the core IV, the core V, the core VI and the core VII, and the core II, the core III, the core IV, the core V, the core VI and the core VII tightly surround the core I.

[0017] A spectral black hole confocal measurement device as described above, the confocal dispersion assembly comprises a collimating lens group 5 and a dispersion focusing lens group 6, the merging end 40 of the multi-core optical fiber 4 is directed towards the collimating lens group 5; when the light beam of the merging end 40 of the multi-core optical fiber 4 is directed onto the collimating lens group 5, the collimating lens group 5 collimates the light beam into parallel light beams and directs them towards the dispersion focusing lens group 6, the dispersion focusing lens group 6 focuses the collimated parallel light beams onto the corresponding surface of the measured panel 8, the reflected light generated by the measured panel 8 is collected by the dispersion focusing lens group 6 and collimated into parallel light beams and then directed onto the collimating lens group 5, the collimating lens group 5 focuses the collimated parallel light beams from the dispersion focusing lens group 6 and directs them onto the merging end 40 of the multi-core optical fiber 4, and then the reflected light beams are transmitted to the light signal processing assembly 7 through the receiving fiber core of the receiving end 44.

[0018] A spectral black hole confocal measurement device as described above, a light blocking sheet is arranged between the merging end 40 of the multi-core optical fiber 4 and the collimating lens group 5, and / or a light blocking sheet is arranged between the collimating lens group 5 and the dispersion focusing lens group 6, and / or a light blocking sheet is arranged between the dispersion focusing lens group 6 and the measured panel 8.

[0019] A spectral black hole confocal measurement device as described above, the light signal processing assembly 7 is a spectrometer or a color sensor.

[0020] A spectral black hole confocal measurement device as described above, further comprising an XY displacement platform 9 for placing the measured panel 8, when measuring, the merging end 40 of the multi-core optical fiber 4 and the confocal dispersion assembly are coaxial, the measured panel 8 is placed on the XY displacement platform 9, by adjusting the axial movement of the XY displacement platform 9, the corresponding surface of the measured panel 8 can be made to coincide with the focal plane of the confocal dispersion assembly.

[0021] A spectral black hole confocal measurement method, using a spectral black hole confocal measurement device as described above, comprising the following steps:

[0022] S1, turn on the wide spectrum light source, the light emitted by the wide spectrum light source is transmitted to the merging end 40 of the multi-core optical fiber 4 through the emitting fiber core of the incident end of the multi-core optical fiber 4 and is directed onto the confocal dispersion assembly;

[0023] S2, the light beam emitted by the merging end 40 of the multi-core optical fiber 4 is axially dispersed and focused on the corresponding surface of the measured panel 8 by the confocal dispersion assembly, and is reflected by the surface of the measured panel 8, the confocal dispersion assembly collects the reflected light from the surface of the measured panel 8 and focuses it on the merging end 40 of the multi-core optical fiber 4;

[0024] S3, when the reflected light is focused, the light focused on the surface of the measured panel 8 will be focused on the emitting fiber core of the multi-core optical fiber 4 merging end 40, and the light corresponding to the wavelength in the spectrum will be defocused on the emitting fiber core of the merging end 40, received by the receiving fiber core of the multi-core optical fiber 4 merging end 40, and transmitted to the optical signal processing assembly 7 through the receiving fiber core of the receiving end of the multi-core optical fiber 4;

[0025] S4, the optical signal processing assembly 7 collects and processes the optical signal, and detects two peak signals and no or low signal values between them, and obtains the measured distance according to the wavelength corresponding to the signal value in the axial dispersion relationship.

[0026] As described above, in the step S4, when the optical signal processing assembly 7 detects two sets of two peak signals and no or low signal values between them, two sets of measured distances are obtained according to the wavelength corresponding to the signal value in the axial dispersion relationship, and the difference between the two sets of measured distances is the thickness of the measured panel 8.

[0027] As described above, in the step S4, the measured panel 8 is placed on the XY displacement platform 9 to move the measured panel 8 in the XY plane, and the surface type of the measured panel 8 can be calculated according to the relationship between the measured distance or thickness and the movement of the measured panel 8 in the XY plane.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] 1. Compared with the existing spectral confocal detection technology, the present application can couple multiple light sources of different spectral ranges, effectively expand the detection spectral range at low cost, and further increase the detection distance.

[0030] 2. Compared with the existing spectral confocal detection technology, in the prior art, in order to realize a wider detection spectrum, a wide-spectrum light source is often used, which is expensive. Through the technical method of the present application, the cost of the equipment can be effectively reduced.

[0031] 3. Compared with the existing spectral confocal detection technology, multiple light sources are used in the present application, which can make the intensity of the detection light source uniform and stable in the entire spectral range, and sufficient for modulation, increase the stability and accuracy of measurement.

[0032] 4. Compared with the existing spectral confocal detection technology, the conjugate focus of the present application is not on the fiber core I receiving the detection signal, so a large amount of central near-axis background light will not be transmitted to the detection fiber core I, which can effectively remove the background signal and improve the detection signal quality.

DRAWINGS

[0033] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram of the structure of the present invention.

[0035] Figure 2 This is a schematic diagram of the incident end cross-section of the multi-core optical fiber of the present invention.

[0036] Figure 3 This is a schematic diagram of the receiving end cross-section of the multi-core optical fiber of the present invention.

[0037] Figure 4 This is a schematic diagram of the combined end cross-section of the multi-core optical fiber of the present invention.

[0038] Figure 5 This is a cross-sectional structural diagram of a portion of the optical path at the multi-core fiber merging end of the present invention.

[0039] Figure 6 This is one of the schematic diagrams showing the image plane distribution near the surface of the panel being tested, with the multi-core fiber merging end face as the object plane according to the present invention.

[0040] Figure 7 This is the second schematic diagram of the image plane distribution near the surface of the panel being tested, where the multi-core fiber merging end face is used as the object plane according to the present invention.

[0041] Figure 8 This is a schematic diagram of the spectral distribution received by the optical signal processing component of the present invention.

Detailed Implementation Methods

[0042] The following is in conjunction with the appendix Figures 1-8 The embodiments of the present invention will be described in detail.

[0043] like Figures 1-8 As shown, the present invention provides a spectroscopic black hole confocal measurement device, which includes the following components arranged sequentially along the optical axis:

[0044] Broadband light source, multi-core fiber 4, and confocal dispersion assembly;

[0045] The broadband light source is used to provide and emit light beams of at least two different wavelengths;

[0046] The multi-core optical fiber 4 has an incident end, a receiving end and a merging end, and the incident end of the multi-core optical fiber 4 includes multiple transmitting cores, the receiving end of the multi-core optical fiber 4 includes a receiving core, and the merging end 40 of the multi-core optical fiber 4 includes the transmitting core of the incident end and the receiving core of the receiving end.

[0047] The emitting core of the incident end of the multi-core optical fiber 4 is coupled to a broadband light source, the merging end 40 of the multi-core optical fiber 4 faces the confocal dispersion component, and the receiving end 44 of the multi-core optical fiber 4 is connected to an optical signal processing component 7.

[0048] The confocal dispersion assembly is used to focus the light beams emitted by the merging end 40 of the multi-core optical fiber 4 in axial dispersion, and collect the reflected light of the corresponding surface of the measured panel 8 and focus on the merging end 40 of the multi-core optical fiber 4.

[0049] The optical signal processing assembly 7 is used to receive and process the optical signals transmitted by the receiving end 44 of the multi-core optical fiber 4. The present application can couple multiple light sources of different spectral ranges, effectively expand the detection spectral range at low cost, and further increase the detection distance.

[0050] The wide-spectrum light source includes a first light source 1 for providing and emitting ultraviolet light, a second light source 2 for providing and emitting visible light, and a third light source 3 for providing and emitting infrared light; the incident end of the multi-core optical fiber 4 includes a first branch end 41, a second branch end 42 and a third branch end 43 corresponding to the coupling connection of the first light source 1, the second light source 2 and the third light source 3. The above combination can expand the spectral range at low cost and increase the light intensity of each spectral segment.

[0051] The incident end of the multi-core optical fiber 4 has a core II, a core III, a core IV, a core V, a core VI and a core VII, the first branch end 41 has a core II and a core V, the second branch end 42 has a core III and a core VI, and the third branch end 43 has a core IV and a core VII; the receiving end 44 of the multi-core optical fiber 4 has a core I; the merging end 40 of the multi-core optical fiber 4 has a core I, a core II, a core III, a core IV, a core V, a core VI and a core VII, and the core II, the core III, the core IV, the core V, the core VI and the core VII closely surround the core I. This distribution of cores can make the obtained black hole spectral peak stronger, the trough more sharp, and more conducive to detection.

[0052] In order to improve the dispersion effect, the confocal dispersion assembly includes a collimating lens group 5 and a dispersion focusing lens group 6, and the merging end 40 of the multi-core optical fiber 4 is directed towards the collimating lens group 5; when the light beams of the merging end 40 of the multi-core optical fiber 4 are shot on the collimating lens group 5, the collimating lens group 5 collimates the light beams into parallel light beams and shoots them on the dispersion focusing lens group 6, the dispersion focusing lens group 6 focuses the collimated parallel light beams on the corresponding surface of the measured panel 8, the reflected light generated by the measured panel 8 is collected by the dispersion focusing lens group 6, collimated into parallel light beams and then shot on the collimating lens group 5, the collimating lens group 5 focuses the collimated parallel light beams shot by the dispersion focusing lens group 6 on the merging end 40 of the multi-core optical fiber 4, and then the reflected light beams are transmitted to the optical signal processing assembly 7 through the receiving core of the receiving end 44.

[0053] For the convenience of detection, an XY displacement platform 9 for placing the measured panel 8 is further included, and when measurement is performed, the merging end 40 of the multi-core optical fiber 4 and the confocal dispersion assembly are coaxially adjusted, the measured panel 8 is placed on the XY displacement platform 9, and by adjusting the axial movement of the XY displacement platform 9, the corresponding surface of the measured panel 8 can be made to coincide with the focal plane of the confocal dispersion assembly.

[0054] A spectral black hole confocal measurement method, using a spectral black hole confocal measurement device as described above, comprises the following steps:

[0055] S1, turn on the wide-spectrum light source, and the light emitted by the wide-spectrum light source is transmitted to the merging end 40 of the multi-core optical fiber 4 from the emitting core of the incident end of the multi-core optical fiber 4 and is shot onto the confocal dispersion assembly;

[0056] S2, the light beam shot from the merging end 40 of the multi-core optical fiber 4 is axially dispersed and focused on the corresponding surface of the measured panel 8 by the confocal dispersion assembly, is reflected by the surface of the measured panel 8, and the confocal dispersion assembly collects the reflected light of the surface of the measured panel 8 and focuses it on the merging end 40 of the multi-core optical fiber 4;

[0057] S3, when the reflected light is focused, the light converging at the focal point on the surface of the measured panel 8 is focused on the emitting core of the merging end 40 of the multi-core optical fiber 4, the light corresponding to the wavelength in the spectrum is out of focus on the emitting core of the merging end 40, is received by the receiving core of the merging end 40 of the multi-core optical fiber 4, and is transmitted to the optical signal processing assembly 7 through the receiving core of the receiving end of the multi-core optical fiber 4;

[0058] S4, the optical signal processing assembly 7 collects the optical signal and processes the optical signal, detects two peak signals and no or low signal values between the two peak signals, and obtains the measured distance according to the axial dispersion relationship of the signal values corresponding to the wavelengths.

[0059] In the step S4, when the optical signal processing assembly 7 detects two sets of two peak signals and no or low signal values between the two peak signals, two sets of measured distances are obtained according to the axial dispersion relationship of the signal values corresponding to the wavelengths, and the difference between the two sets of measured distances is the thickness of the measured panel 8.

[0060] In the step S4, the measured panel 8 is placed on the XY displacement platform 9 to move the measured panel 8 in the XY plane, and the surface type of the measured panel 8 can be calculated according to the relationship between the measured distance or thickness and the movement of the measured panel 8 in the XY plane.

[0061] As shown in Figures 1-8 A spectral black hole confocal measurement device of the present application is provided in sequence along an optical axis:

[0062] a wide-spectrum light source, a multi-core optical fiber 4, a collimating lens group 5, a dispersion focusing lens group 6, and an XY displacement platform 9.

[0063] The wide spectrum light source is used for providing and emitting light beams of at least two different wave bands, and comprises a first light source 1, a second light source 2 and a third light source 3.

[0064] The multi-core optical fiber 4 has an incident end, a merging end and a receiving end, the incident end of the multi-core optical fiber 4 comprises a first branch end 41, a second branch end 42 and a third branch end 43 which are respectively coupled with the first light source 1, the second light source 2 and the third light source 3, the merging end 40 of the multi-core optical fiber 4 is directed to the collimating lens group 5, and the receiving end 44 of the multi-core optical fiber 4 is connected with the optical signal processing assembly 7; the merging end 40 of the multi-core optical fiber 4 has a core I, a core II, a core III, a core IV, a core V, a core VI and a core VII, and the core I is surrounded by the core II, the core III, the core IV, the core V, the core VI and the core VII; the incident end of the multi-core optical fiber 4 has the core II, the core III, the core IV, the core V, the core VI and the core VII, the first branch end 41 has the core II and the core V, the second branch end 42 has the core III and the core VI, and the third branch end 43 has the core IV and the core VII; the receiving end 44 of the multi-core optical fiber 4 has the core I.

[0065] The optical signal processing assembly 7 is used for receiving and processing signals.

[0066] The collimating lens group 5 and the dispersion focusing lens group 6 are used for collimation and focusing; when the light beams of the merging end 40 of the multi-core optical fiber 4 are shot on the collimating lens group 5, the collimating lens group 5 collimates the light beams into parallel light beams and shoots them on the dispersion focusing lens group 6, the dispersion focusing lens group 6 focuses the collimated parallel light beams on the corresponding surface of the measured panel 8, the reflected light generated by the measured panel 8 is collected by the dispersion focusing lens group 6 and collimated into parallel light beams and then shot on the collimating lens group 5, the collimating lens group 5 focuses the parallel light beams collimated by the dispersion focusing lens group 6 and shoots them on the cores of the merging end 40 of the multi-core optical fiber 4, and then the reflected light beams are transmitted to the optical signal processing assembly 7 through the core I of the receiving end 44.

[0067] During measurement, the merging end 40 of the multi-core optical fiber 4, the collimating lens group 5 and the dispersion focusing lens group 6 are coaxial, the measured panel 8 is placed on the XY displacement platform 9, and the corresponding surface of the measured panel 8 can be made to coincide with the focal plane of the dispersion focusing lens group 6 by adjusting the axial movement of the XY displacement platform 9. The present application can effectively reduce the cost of equipment, and the conjugate focal point of the present application is not on the core I for receiving and detecting signals, so a large amount of central near-axis background light cannot be transmitted to the detection core I, the background signal can be effectively removed, and the quality of the detection signal is improved.

[0068] The spectral confocal measuring device is scientifically and reasonably designed by a wide-spectrum light source, a multi-core optical fiber, a collimating lens group, a dispersion focusing lens group, an XY displacement platform and a light signal processing assembly, so that part of defocused light around the confocal focus in the optical system can be obtained, and then the light signal processing assembly obtains a spectral signal with a certain width wave peak and a sharp wave trough in the middle, according to the wave trough in the obtained spectral signal and the wave peak value data on both sides, processing and multiple calculation are performed, and according to the displacement relationship between the calculated value and the measured panel in unit time, the surface type or thickness of the measured panel can be efficiently and accurately calculated without contact.

[0069] Preferably, the multi-core optical fiber is a 6+1 multi-core optical fiber.

[0070] In order to detect more conveniently, the light signal processing assembly 7 is a spectrometer or a color sensor.

[0071] The first light source 1 is used for providing and emitting ultraviolet light, the second light source 2 is used for providing and emitting visible light, and the third light source 3 is used for providing and emitting infrared light, wherein different waveband light sources can also be structured, more light sources are used to expand the spectral range of detection; in addition, multiple light sources are used in the present application, so that the intensity of the detection light source in the entire spectral range is uniform, stable and sufficient, which is convenient for modulation, increases the stability and measurement accuracy of measurement.

[0072] A light blocking sheet is arranged between the merging end 40 of the multi-core optical fiber 4 and the collimating lens group 5, and / or a light blocking sheet is arranged between the collimating lens group 5 and the dispersion focusing lens group 6, and / or a light blocking sheet is arranged between the dispersion focusing lens group 6 and the measured panel 8, and the light blocking sheet is used to block the central light of the light path to form a ring-shaped light beam and improve the measurement accuracy.

[0073] The spectral black hole confocal measuring method of the present application uses a spectral black hole confocal measuring device as described above, and includes the following steps:

[0074] S1, the first branch end 41, the second branch end 42 and the third branch end 43 are respectively connected to the first light source 1, the second light source 2 and the third light source 3, and the merging end 40 of the multi-core optical fiber 4, the collimating lens group 5, the dispersion focusing lens group 6 and the XY displacement platform 9 are coaxial;

[0075] S2, the wide-spectrum light source is turned on, and the light beams emitted by the first light source 1, the second light source 2 and the third light source 3 are respectively incident on the first branch end 41, the second branch end 42 and the third branch end 43, and then pass through the fiber core II, the fiber core III, the fiber core IV, the fiber core V, the fiber core VI and the fiber core VII to be incident on the collimating lens group 5 through the merging end 40 of the multi-core optical fiber 4;

[0076] S3, the collimating lens group 5 collimates the light beam emitted from the merging end 40 of the multi-core optical fiber 4 into parallel light beams and then emits the parallel light beams to the dispersion focusing lens group 6;

[0077] S4, the dispersion focusing lens group 6 focuses the parallel light beams collimated by the collimating lens group 5 to the corresponding surface of the measured panel 8, reflects the light beams on the surface of the measured panel 8, collects the reflected light beams of the surface of the measured panel 8, collimates the light beams into parallel light beams and emits the parallel light beams to the collimating lens group 5, and the collimating lens group 5 focuses the parallel light beams collimated by the dispersion focusing lens group 6 to the core of the merging end 40 of the multi-core optical fiber 4;

[0078] S5, the core of the merging end 40 of the multi-core optical fiber 4 transmits the reflected light beams of the measured panel 8 to the core I of the receiving end 44 of the multi-core optical fiber 4, so that the light signal processing assembly 7 receives the light signal, and the light spectrum signal received by the light signal processing assembly 7 should be a light spectrum signal with two wave peaks with a certain width and a sharp wave valley between the two wave peaks;

[0079] S6, when the XY displacement platform 9 on which the measured panel 8 is placed is moved along the axial direction, the upper surface or the lower surface of the measured panel 8 is coincided with the focal plane of the dispersion focusing lens group 6 during the movement, the light signal processing assembly 7 can receive the light signal reflected by the corresponding surface of the measured panel 8, and the computer connected with the light signal processing assembly 7 processes the corresponding light spectrum signal, processes and calculates the data of the two wave valleys and the wave peaks on both sides in the obtained light spectrum, since the wave peak has a certain width, a plurality of groups of data are obtained for multiple calculations, according to the displacement relationship between the calculated values and the measured panel 8 in unit time, the surface shape of the measured panel 8 can be calculated.

[0080] When the XY displacement platform 9 on which the measured panel 8 is placed is moved along the axial direction, the upper surface or the lower surface of the measured panel 8 is coincided with the focal plane of the dispersion focusing lens group 6 during the movement, the light signal processing assembly 7 can receive the light signal reflected by the corresponding surface of the measured panel 8, and the computer connected with the light signal processing assembly 7 processes the corresponding light spectrum signal, processes and calculates the data of the two wave valleys and the wave peaks on both sides in the obtained light spectrum, since the wave peak has a certain width, a plurality of groups of data are obtained for multiple calculations, according to the displacement relationship between the calculated values and the measured panel 8 in unit time, the surface shape of the measured panel 8 can be calculated.

[0081] In the present application, when the measured panel 8 is opaque, the surface shape of the measured panel 8 can be measured, and when the measured panel 8 is transparent, the surface shape and the thickness of the measured panel 8 can be measured.

[0082] As Figure 5 shown, where a longitudinal cross-section of the merging end 40 of the multi-core optical fiber 4 is taken as an example. Figure 5 The light beams 20, 21 and 22 are the light emitted by the fiber core III, after passing through the confocal system, reflected by the corresponding surface of the measured panel 8, and after passing through the dispersion lens group 6 and the collimation lens group 5, converged on the light path on the merging end 40 of the multi-core optical fiber 4. Among them, the light beam 21 is a confocal light beam, according to the confocal principle, the two conjugate focal points of the light beam 21 are on the corresponding surface of the measured panel 8 and on the fiber core III, respectively, and the light beams 20 and 22 are part of the defocused light around the confocal light. The light beam 21 converges on the fiber core III and is not received by the fiber core I, while part of the light beams 20 and 22 will irradiate on the fiber core I, and the light will be received by the fiber core I in order to facilitate the light signal processing assembly 7 to receive the light signal. Therefore, the light signal processing assembly 7 will receive a spectrum signal with a sharp trough as the confocal point and a certain width peak on both sides, as shown in Figure 8 .

[0083] As Figure 6 , 7 shown, the image planes 30, 31, 32, 33 and 34 are the spectral expansion on the axis of the different central position wavelengths of the end surface of the merging end 40 of the multi-core optical fiber 4, among which the shorter wavelength near the lens is ultraviolet light, and the light spot image area represented by the shadow indicated by 37; the middle part is the spectral expansion plane of visible light, and the light spot image area represented by the shadow indicated by 38; the area near the measured panel 8 is usually infrared light, and the light spot image area represented by the shadow indicated by 39. The central position wavelength light reflected by the corresponding surface of the measured panel is transmitted to the conjugate point of the emitting fiber core through the confocal system, and will not be transmitted to the receiving fiber core I, while the light near the conjugate wavelength will be partially transmitted into the detection fiber core I, which is detected by the light signal processing assembly 7, and appears as a black hole of the spectrum with a peak value depression. Among them, the light beam 35 is the shortest wavelength light, and the light beam 36 is the longest wavelength light, and the wavelength interval corresponds to the detectable range.

[0084] In an embodiment of the spectrum black hole confocal measurement method, ultraviolet, visible and infrared light sources of three wave bands are used, or a plurality of light sources of different wave bands can be combined to obtain a wide spectrum output light source with continuous, stable and high intensity. In the entire optical system of the present application, it is required that the light beams emitted by the illumination light source have high collimation degree, sufficient spectral width, stable output and sufficient energy efficiency.

[0085] In an embodiment of the spectral black hole confocal measurement method, a spectrometer is used to receive and process the light signal, the correspondence between distance and wavelength is established by axial tomographic characteristics and optical dispersion principle, and the trough signal obtained by the spectrometer and the peak signals on both sides of the trough are analyzed. The peak signals on both sides correspond to each other, and because the peak has a certain width, a plurality of sets of effective sampling data can be obtained. Through sampling and processing of the plurality of sets of trough and peak data, the corresponding wavelength can be obtained accurately, so as to obtain the position information and further measure the thickness or surface shape of the measured panel.

Claims

1. A spectroscopic black hole confocal measurement device, characterized in that... Along the optical axis are arranged in sequence as follows: Broad-spectrum light source, multi-core optical fiber (4) and confocal dispersion assembly; The broadband light source is used to provide and emit light beams of at least two different wavelengths; The multi-core optical fiber (4) has an incident end, a receiving end and a merging end, and the incident end of the multi-core optical fiber (4) contains multiple transmitting cores, the receiving end of the multi-core optical fiber (4) contains a receiving core, and the merging end (40) of the multi-core optical fiber (4) contains the transmitting core of the incident end and the receiving core of the receiving end. The emitter core of the multi-core optical fiber (4) is coupled to a broadband light source at the incident end. The merging end (40) of the multi-core optical fiber (4) faces the confocal dispersion component. The receiving end (44) of the multi-core optical fiber (4) is connected to an optical signal processing component (7). The confocal dispersion component is used to axially disperse and focus the beam emitted from the merging end (40) of the multi-core fiber (4), and collect the reflected light from the corresponding surface of the panel under test (8) and focus it onto the merging end (40) of the multi-core fiber (4). The optical signal processing component (7) is used to receive and process the optical signal transmitted from the receiving end (44) of the multi-core optical fiber (4); The broadband light source includes a first light source (1) for providing and emitting ultraviolet light, a second light source (2) for providing and emitting visible light, and a third light source (3) for providing and emitting infrared light; the incident end of the multi-core optical fiber (4) includes a first branch end (41), a second branch end (42), and a third branch end (43) corresponding to the first light source (1), the second light source (2), and the third light source (3). The multi-core optical fiber (4) has cores II, III, IV, V, VI and VII at its incident end; the first branch end (41) has cores II and V; the second branch end (42) has cores III and VI; and the third branch end (43) has cores IV and VII. The multi-core optical fiber (4) has core I at its receiving end (44); and the multi-core optical fiber (4) has cores I, II, III, IV, V, VI and VII at its merging end (40), with cores II, III, IV, V, VI and VII closely surrounding core I. Since the conjugate focus is not on fiber core I, which receives the detection signal, a large amount of central paraxial background light will not be transmitted to the detection fiber core I.

2. The spectroscopic black hole confocal measurement device according to claim 1, characterized in that... The confocal dispersion assembly includes a collimating lens group (5) and a dispersion focusing lens group (6). The merging end (40) of the multi-core fiber (4) faces the collimating lens group (5). When the beam from the merging end (40) of the multi-core fiber (4) is directed toward the collimating lens group (5), the collimating lens group (5) collimates the beam into a parallel beam and directs it toward the dispersion focusing lens group (6). The dispersion focusing lens group (6) then focuses the collimated parallel beam onto the corresponding surface of the panel under test (8). The reflected light generated by the panel under test (8) is collected by the dispersion focusing lens group (6) and collimated into a parallel beam before being directed toward the collimating lens group (5). The collimating lens group (5) then focuses the parallel beam collimated by the dispersion focusing lens group (6) toward the merging end (40) of the multi-core fiber (4). The reflected beam is then transmitted to the optical signal processing assembly (7) through the receiving fiber core of the receiving end (44).

3. The spectroscopic black hole confocal measurement device according to claim 2, characterized in that... A light-blocking plate is provided between the merging end (40) of the multi-core optical fiber (4) and the collimating lens group (5), and / or a light-blocking plate is provided between the collimating lens group (5) and the dispersive focusing lens group (6), and / or a light-blocking plate is provided between the dispersive focusing lens group (6) and the panel under test (8).

4. A spectroscopic black hole confocal measurement device according to any one of claims 1-3, characterized in that... The optical signal processing component (7) is a spectrometer or a color sensor.

5. A spectroscopic black hole confocal measurement device according to any one of claims 1-3, characterized in that... It also includes an XY displacement platform (9) for placing the panel under test (8). When measuring, the merging end (40) of the multi-core fiber (4) and the confocal dispersion component are adjusted to be coaxial, and the panel under test (8) is placed on the XY displacement platform (9). By adjusting the axial movement of the XY displacement platform (9), the corresponding surface of the panel under test (8) can be made to coincide with the focal plane of the confocal dispersion component.

6. A method for measuring the confocal spectrum of black holes, characterized in that... Using the spectral black hole confocal measurement device according to any one of claims 1-5, the following steps are included: S1. Turn on the broadband light source. The light emitted by the broadband light source is transmitted through the emitting core of the incident end of the multi-core optical fiber (4) to the merging end (40) of the multi-core optical fiber (4) and is directed onto the confocal dispersion component. S2. The beam emitted from the merging end (40) of the multi-core fiber (4) is axially dispersed and focused onto the corresponding surface of the panel under test (8) by the confocal dispersion component. The beam is reflected by the surface of the panel under test (8), and the confocal dispersion component collects the reflected light from the surface of the panel under test (8) and focuses it onto the merging end (40) of the multi-core fiber (4). S3. When the reflected light is focused, the light focused on the surface of the panel under test (8) will be focused on the emitting core of the merging end (40) of the multi-core fiber (4). The light near the corresponding wavelength in the spectrum of the reflected light will be defocused on the emitting core of the merging end (40), received by the receiving core of the merging end (40) of the multi-core fiber (4), and transmitted to the optical signal processing component (7) through the receiving core of the receiving end of the multi-core fiber (4). S4. The optical signal processing component (7) collects and processes the optical signal. The optical signal processing component (7) will detect two peak signals and the no or low signal value in between. Based on the axial dispersion relationship of the corresponding wavelength of the signal value, the measured distance is obtained.

7. The method for measuring confocal spectroscopic black holes according to claim 6, characterized in that... In step S4, when the optical signal processing component (7) detects two sets of peak signals and no or low signal values ​​in between, it obtains two sets of measured distances based on the axial dispersion relationship of the wavelengths corresponding to the signal values. The difference between the two sets of measured distances is the thickness of the panel (8) being measured.

8. The method for measuring confocal spectroscopic black holes according to claim 6, characterized in that... In step S4, the panel to be tested (8) is placed on the XY displacement platform (9) so that the panel to be tested (8) moves in the XY plane. Based on the relationship between the change of the measured distance or thickness and the movement of the panel to be tested (8) in the XY plane, the surface shape of the panel to be tested (8) can be calculated.

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