TW201315987A - Device for deformation measurement and method thereof - Google Patents

Abstract

The present invention discloses a device for deformation measurement and a method thereof. The device comprises a light source module, an image capture module and a processing module. The light source module emits a light source, and the light source is split into an object light and a reference light. The image capture module captures an interference image that is interference by a reflected object light and a reflected reference light. The processing module calculates an optical path difference or a phase that the object light passes through a unit under test. The processing module calculates a deformation angle of the unit under test according to the optical path difference or the phase.

Description

Deformation measuring device and deformation measuring method thereof

The invention relates to a deformation measuring device and a deformation measuring method thereof, in particular to a deformation measuring device for measuring a transparent object and a deformation measuring method thereof.

At present, most of electronic products are designed with convenience, lightness, and impact resistance. Therefore, in order to manufacture a product that is convenient, light, and impact-resistant, a transparent polymer substrate structural material can be used to manufacture related electronic products. However, when a transparent polymer substrate is easily deformed due to high temperature at the time of manufacture, measurement and detection techniques are relatively important.

In general, optical measurement technology has the advantages of high precision, noncontact, nondestructive and global, and has been widely used in different fields of detection and research. In most optical measurement techniques, in order to measure the global deformation distribution of an object, the object is measured by light irradiation, and after reflection by the surface, the reflected light with the deformation information of the object interferes with the reference light, such as Chinese Republic of China Patent Publication No. I333059. However, the transparent polymer substrate structure itself has a highly transparent property, making the general optical measurement method difficult.

Therefore, in 2010, Xu and Liechti of the University of Texas at Austin published a technique for measuring the deformation of transparent ethylene terephthalate (PET) film by moiré phenomenon. Although this method can measure for transparent objects, if the film changes geometry or load conditions, and the deformed shape is different from the lens shape, it cannot be measured. Moreover, this method only measures the deformation radius of curvature of the test piece of the entire piece of the test piece, and cannot measure the local deformation of the film.

In other words, although many methods have been used to study the mechanical behavior of the above methods, it is feared that the bottleneck cannot be broken by the measurement technology, so that more detailed deformation characteristics cannot be obtained.

Therefore, in order to overcome the shortcomings of the technique of measuring the deformation of transparent objects, a deformation measuring device and a deformation measuring method thereof are designed to establish an optical measuring method capable of measuring the globality and large deformation of the transparent object.

In view of the above-mentioned problems of the prior art, the object of the present invention is to provide a deformation measuring device and a deformation measuring method thereof for measuring the global deformation of a transparent object.

According to the purpose of the present invention, a deformation measuring device is provided, which comprises a light source module, an image capturing module and a processing module. The light source module emits a light source, and the light source passes through the polarizing plate and the spatial filter to form a diffused light source, and the diffused light source passes through the collimating mirror to convert into parallel light, and the parallel light passes through the beam splitter to obtain the object light or the reference light. The image capturing module captures an interference image between the reflected light and the reflected reference light. The processing module is electrically connected to the image capturing module, and the processing module calculates the optical path difference or phase of the object light passing through the unit to be tested, and calculates the deformation angle of the transparent object according to the optical path difference or phase.

Wherein, the object light passes through the unit to be tested and is reflected by the first mirror to form reflector light.

Wherein, the reference light system passes through the air and is reflected by the second mirror to form a reflected reference light.

The interference image is reflected by the reflected light and the reflected reference light in the image capturing module to obtain an interference image including interference fringes.

The interference fringe is the contour distribution of the deformation angle of the unit to be tested, and the processing module calculates the global deformation distribution according to the deformation angle of the object, and satisfies the following relationship:
W _i+1 =W _i +θ _i+1 △X _i+1 ,
Where W _i+1 is the out-of-plane displacement of the i+1th pixel, Wi is the out-of-plane displacement of the ith pixel, θ _i+1 is the deformation angle of the i+1th pixel, and ΔX _i+1 is the i+th The distance between 1 pixel and the ith pixel.

The utility model further comprises a display module and an electrical connection processing module, which is used for displaying interference images and global deformation distribution.

According to the object of the present invention, a deformation measuring method is further applied to a deformation measuring device, which comprises the steps of: turning on a light source module to emit a light source; using a light source through a polarizing plate, a spatial filter, a collimating mirror, and The beam splitter is used to obtain the object light or the reference light; the image capturing module is opened to capture the interference image of the reflected object light and the reflected reference light; and the processing module calculates the optical path difference and phase of the object light passing through the unit to be tested; The group calculates the deformation angle of the unit to be tested based on the optical path difference or phase.

Wherein, the method further provides the object light passing through the unit to be tested; and reflects the object light with the first mirror to form the reflector light.

Wherein, the method further provides reference light to pass through the air; and the second mirror reflects the reference light to form the reflected reference light.

The method further provides that the reflector light and the reflected reference light interfere with the image capturing module; and the image capturing module is opened to capture the interference image including the interference fringes.

The interference fringe of the method is a contour distribution of the deformation angle of the unit to be tested, and the processing module is used to calculate the global distribution according to the deformation angle.

The method further provides a display module to display an interference image and a global deformation distribution.

In summary, the deformation measuring device and the deformation measuring method thereof of the present invention can overcome the deficiencies of the conventional techniques for measuring transparent objects, and establish an optical measuring method capable of measuring the globality and large deformation of a transparent object.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

The embodiments of the deformation measuring device and the deformation measuring method thereof according to the present invention will be described below with reference to the related drawings. For the sake of understanding, the same components in the following embodiments are denoted by the same reference numerals.

1 is a schematic diagram of a deformation measuring device of the present invention. As shown in the figure, the deformation measuring device of the present invention comprises a light source module 11, an image capturing module 16, a processing module 18, and a display. Module 19. It should be noted that the unit to be tested 1 measured by the deformation measuring device of the present invention may preferably be a transparent object, such as a transparent substrate, a flexible optical transparent substrate or a flexible optical transparent film substrate. At the same time, the unit to be tested 1 can be disposed on the carrying mechanism 2, and the size of the external force is controlled by the carrying mechanism 2, or the unit to be tested 1 can have residual deformation, and no external force is required. Further, the light source module 11 can emit a light source, and the light source can be He-Ne Laser, carbon dioxide laser, ultraviolet laser or visible light laser, etc., preferably 氦氖 laser light. The image capturing module 16 may include a photosensitive element such as a Complementary Metal-Oxide-Semiconductor (CMOS), a Charge-Coupled-Device (CCD) or a lens, a lens group, and the like.

The light source module 11 of the deformation measuring device of the present invention can emit a light source. The light source can pass through the polarizing plate 12 and the spatial filter 13, expand and filter the light source to form a diffused light source, and the polarizing plate 12 has a light intensity adjustable. The effect. The diffusing light source is converted into parallel light by the collimating mirror 14, and the flat light passes through the beam splitter 15, and the parallel light can be divided into object light and reference light. The reference light can travel in the air, and the object light can pass through the unit to be tested 1. The object light passing through the unit to be tested 1 and having the deformation information is reflected by the first mirror 171 to form the reflector light, and the reference light passing through the air is reflected by the second mirror 172 to form the reflected reference light. The reflected light and the reflected reference light pass through the beam splitter 15. The spectroscope 15 interferes with the reflected light and the reflected reference light, and the image capturing module 16 captures the interference image with the interference fringes.

As described above, the interference fringe is a contour distribution of the deformation angle of the unit 1 to be tested, and the processing module 18 can be used to calculate the optical path difference or phase of the light traveling through the unit to be tested 1 . Further, the second mirror 172 reflects the reference light passing through the air, generates a displacement on the second reflective lens, and calculates the interference fringe phase according to the displacement. The interference fringe phase is used to calculate the incident angle of the object light entering the unit to be tested 1, and the light incident on the object light is parallel light, so that the incident angle can be equal to the deformation angle of the bending deformation of the unit 1 to be tested.

In addition, the display module 19 can be a liquid crystal display (LCD) or a touch liquid crystal screen, and can display an interference image or a global deformation distribution.

Therefore, the deformation measuring device of the present invention can calculate the global deformation distribution for the transparent object, and at the same time has the functions of real time measurement and measurable deformation distribution under a large area. The light source module 11 , the polarizing plate 12 , the spatial filter 13 , the collimating mirror 14 , the beam splitting mirror 15 , the image capturing module 16 , the first reflecting mirror 171 , the processing module 18 , or the display module 19 can be used. It is set and fixed on the optical table 3 to increase the accuracy in measurement.

Incidentally, those having ordinary knowledge in the field to which the present invention pertains should be aware of the light source module 11, the polarizing plate 12, the spatial filter 13, the collimating mirror 14, the beam splitter 15, and the image capturing method described above. The implementation of the position of the module 16, the first mirror 171 or the second mirror 172 is merely an example and not a limitation; in addition, those skilled in the art can arbitrarily combine the above functional modules or optical components. The integrated module, or split into individual functional detail units, depends on the convenience of the design.

2 to 4 are first, second and third schematic views of the first embodiment of the deformation measuring device of the present invention. The unit to be tested is preferably a transparent object, such as a transparent substrate, a flexible optically transparent substrate or a flexible optically transparent film substrate. To facilitate a better understanding of the technical features of the present invention, an optically transparent substrate is used as an embodiment. But it is not limited to this. Please refer to FIG. 2, which is a traveling route of light passing through the air and an optical transparent substrate free from external force. As shown in the figure, the phase of the light traveling through the optical transparent substrate is:
;
Wherein, the phase generated by the optical path through the optically transparent substrate is the thickness of the optically transparent substrate, the wavelength of light, n ₁ is the refractive index of air, and n ₂ is the refractive index of the optically transparent substrate.

When the object light enters the optically transparent substrate, the optical path distance through which the object light passes can satisfy the following relationship:
;
Where d is the distance traveled by the light in the transparent substrate, t is the thickness of the optically transparent substrate, and θ ₂ is the angle of refraction (not shown).

Next, referring to FIG. 3 and FIG. 4 , when the optically transparent substrate is disposed on the supporting mechanism and subjected to the load force to bend and deform the optically transparent substrate, the light traveling path of the light passing through the optical transparent substrate is as shown in FIG. 3 and Figure 4 shows. Further, please refer to FIG. 1 together, when the light source module 11 emits the light source, the polarizing plate 12 and the spatial filter 13 are used to expand and filter the point light source to form a diffused light source, and the polarizing plate 12 has Convenient to adjust the light intensity. The diffused light source is then passed through a collimating mirror 14, which converts the diffused light source into parallel light, and then passes through the beam splitter 15 to split the parallel light into two lights. One of the light travels in the air as a reference light, and the other light passes through an optically transparent substrate that is deformed by a load, which is a matter light. The two lights are reflected back to the beam splitter 15 via the first mirror 171 or the second mirror 172, and the image capturing module 16 generates interference, and the image capturing module 16 extracts the reflected light and the reflected reference light. Interfere with the image. Since the object light can pass through the optically transparent substrate twice, the following relationship can be satisfied:
;
Where θ ₁ is the incident angle, which is the phase generated by the light passing through the optically transparent substrate, is the thickness of the optically transparent substrate, is the wavelength of light, and n ₂ is the refractive index of the optically transparent substrate.

Then, the processing module 18 can obtain the intensity of the interference fringes and can satisfy the following relationship:
;
Where φ is the phase, I ₁ is the intensity of the interference fringes, I _o is the light intensity of the object light, and _Ir is the light intensity of the reference light.

It is worth mentioning that the piezoelectric ceramic material (PZT) can be used to shift the reference light to the second mirror 172, and the phase can be changed. When the phase is changed to π/2, π, 3π/2, the light intensity can be changed. Meet the following relationship:
;
;
;
Where φ is the phase, I ₂ is the intensity of the interference fringe with a phase of π/2, I ₃ is the intensity of the interference fringe with a phase of π, and I ₄ is the intensity of the interference fringe with a phase of 3π/2, I _o is the light intensity of the object light, and _Ir is the light intensity of the reference light.

Therefore, the processing module 18 can obtain the phase of the interference fringe according to the light intensity after the phase change, and can satisfy the following relationship:
;
Where φ is the phase, I ₁ is the intensity of the interference fringe, I ₂ is the intensity of the interference fringe with a phase of π/2, I ₃ is the intensity of the interference fringe with a phase π, and I ₄ is the phase of 3π/ 2 The intensity of the interference fringes.

It can be seen from the above that the meaning of the interference fringes obtained by the present invention is the contour line of the deformation angle of the transparent object, and the global deformation angle distribution of the transparent object can be obtained through the above calculation, and the processing module 18 can be further determined according to the deformation angle. Calculate the global deformation distribution and satisfy the following relationships:
W _i+1 =W _i +θ _i+1 △X _i+1 ,
Where W _i+1 is the out-of-plane displacement of the i+1th pixel, Wi is the out-of-plane displacement of the ith pixel, θ _i+1 is the deformation angle of the i+1th pixel, and ΔX _i+1 is the i+th The distance between 1 pixel and the ith pixel.

Although the foregoing description of the deformation measuring method of the present invention has been described in the course of explaining the deformation measuring apparatus of the present invention, for the sake of clarity, the detailed description of the flowchart will be further described below.

Please refer to FIG. 5 , which is a flowchart of a deformation measuring method according to the present invention. As shown in the figure, the deformation measuring method of the present invention is applicable to a deformation measuring device, and the deformation measuring device comprises a light source. The module, an image capture module, a processing module and a display module. The deformation measurement method of the deformation measuring device comprises the following steps:

In step S101, the light source module is turned on to emit the light source.

In step S102, the light source is passed through a polarizing plate, a spatial filter, a collimating mirror, and a beam splitter to obtain object light or reference light.

In step S103, the object light or the reference light is reflected by the first mirror or the second mirror to form the reflector light or the reflected reference light.

In step S104, the image capturing module is turned on to capture an interference image between the reflected light and the reflected reference light.

In step S105, the optical path difference and phase of the object light passing through the unit to be tested are calculated by the processing module.

In step S106, the processing module calculates the light intensity of the plurality of interference fringes according to the light intensity of the object light and the light intensity of the reference light.

In step S107, the interference fringe phase is calculated by the processing module according to the displacement of the reference light on the second mirror.

In step S108, the transmission processing module calculates an incident angle or a deformation angle according to the interference fringe phase.

In step S109, the processing module is used to calculate the global deformation distribution according to the deformation angle.

In step S110, the interference image and the global deformation distribution are displayed using the display module.

The detailed description and the embodiment of the deformation measuring method of the deformation measuring device of the present invention have been described in the foregoing description of the deformation measuring device of the present invention, and will not be described here for the sake of brevity.

In summary, the deformation measuring device and the deformation measuring method thereof according to the present invention may have one or more of the following advantages:

(1) The deformation measuring device and the deformation measuring method thereof of the invention can overcome the deficiencies of the conventional transparent substrate structure measuring technology, and establish an optical measuring method capable of measuring the globality and large deformation of the transparent substrate structure.

(2) The deformation measuring device and the deformation measuring method thereof of the present invention can be applied to measuring deformation and residual stress generated in a transparent substrate structure due to manufacture.

The above is intended to be illustrative only and not limiting. Any person skilled in the art will be able to make some modifications and refinements without departing from the spirit and scope of the invention, and the scope of the invention is defined by the scope of the appended claims.

1. . . Unit to be tested

2. . . Carrying mechanism

3. . . Optical platform

11. . . Light source module

12. . . Polarizer

13. . . Spatial filter

14. . . Collimating mirror

15. . . Beam splitter

16. . . Image capture module

171. . . First mirror

172. . . Second mirror

18. . . Processing module

19. . . Display module

S101~S110. . . Step flow

θ ₁ . . . Incident angle

θ ₂ . . . Refraction angle

n ₁ . . . Air refractive index

n ₂ . . . Refractive index of optically transparent substrate

d. . . The distance traveled by a transparent object

t. . . Thickness of optically transparent substrate

△. . . Optical path difference

Φ. . . Phase

I ₁ . . . Light intensity of interference fringes

I ₂ . . . Light intensity of interference fringes with phase π/2

I ₃ . . . Light intensity of interference fringes with phase π

I ₄ . . . Light intensity of interference fringes with a phase of 3π/2

I _o . . . Light of matter

I _r . . . Reference light intensity

as well as

λ. . . Wavelength of the light source

Figure 1 is a schematic view of a deformation measuring device of the present invention;
2 is a first schematic view of a first embodiment of a deformation measuring device of the present invention;
Figure 3 is a second schematic view of the first embodiment of the deformation measuring device of the present invention;
4 is a third schematic view of the first embodiment of the deformation measuring device of the present invention; and FIG. 5 is a flow chart of the deformation measuring method of the present invention.

1. . . Unit to be tested

2. . . Carrying mechanism

3. . . Optical platform

11. . . Light source module

12. . . Polarizer

13. . . Spatial filter

14. . . Collimating mirror

15. . . Beam splitter

16. . . Image capture module

171. . . First mirror

172. . . Second mirror

18. . . Processing module

as well as

19. . . Display module

Claims (12)

A deformation measuring device comprising:
a light source module emits a light source, and the light source passes through a polarizing plate and a spatial filter to form a diffused light source, and the diffused light source is converted into a parallel light by a collimating mirror, and the flat light passes through a splitting light Mirror to obtain a light or a reference light;
An image capturing module is configured to capture an interference image between a reflective object and a reflective reference light; and a processing module electrically coupled to the image capturing module, wherein the processing module calculates the light passing through the image An optical path difference or a phase of one of the units to be tested, and calculating a deformation angle of the unit to be tested according to the optical path difference or the phase.
The deformation measuring device according to claim 1, wherein the object light passes through the unit to be tested and is reflected by a first mirror to form the reflector light.
The deformation measuring device of claim 1, wherein the reference light passes through the air and is reflected by a second mirror to form the reflected reference light.
The deformation measuring device according to claim 1, wherein the interference image is caused by the reflection of the reflector light and the reflection reference light to obtain an interference image including an interference fringe.
The deformation measuring device according to claim 1, wherein the interference fringe is a contour distribution of the deformation angle of the unit to be tested, and the processing module calculates a global deformation distribution according to the deformation angle, and satisfies The following relationship:
W _i+1 =W _i +θ _i+1 △X _i+1 ,
Where W _i+1 is the out-of-plane displacement of the i+1th pixel, Wi is the out-of-plane displacement of the ith pixel, θ _i+1 is the deformation angle of the i+1th pixel, and ΔX _i+1 is the i+th The distance between 1 pixel and the ith pixel.
The deformation measuring device according to claim 5, further comprising a display module electrically connected to the processing module for displaying the interference image or the global deformation distribution.
A deformation measuring method is applicable to a deformation measuring device, and the deformation measuring method comprises the following steps:
Opening a light source module to emit a light source;
Using the light source, a polarizing plate, a spatial filter, a collimating mirror and a beam splitter to obtain a light or a reference light;
Opening an image capturing module to capture an interference image between a reflector light and a reflected reference light;
Calculating, by a processing module, an optical path difference and a phase of the object passing through a unit to be tested; and calculating, by the processing module, a deformation angle of the unit to be tested according to the optical path difference or the phase.
The deformation measurement method described in claim 7 of the patent application further includes the following steps:
Providing the object light through the unit to be tested; and reflecting the object light with a first mirror to form the reflector light.
The deformation measurement method described in claim 7 of the patent application further includes the following steps:
Providing the reference light through the air; and reflecting the reference light with a second mirror to form the reflected reference light.
The deformation measurement method described in claim 7 of the patent application further includes the following steps:
Providing the reflector light and the reflected reference light to interfere with the image capturing module; and opening the image capturing module to capture the interference image including an interference fringe.
The deformation measurement method according to claim 7, wherein the interference fringe is a contour distribution of the deformation angle of the unit to be tested, and the processing module calculates a global deformation distribution according to the deformation angle.
For example, the deformation measurement method described in claim 11 further includes the following steps:
A display module is provided to display the interference image or the global deformation distribution.