CN102053398B - Liquid crystal pretilt angle measurement system and method - Google Patents

Abstract

The invention provides a liquid crystal pretilt angle measurement system and a liquid crystal pretilt angle measurement method. The method comprises the following steps of: projecting linear polarized beams to a sample to be measured, and separating penetrating light passing through the sample to be measured by using a polarized light receiving module to form light beams with vertical and horizontal polarization states; calculating normalized penetrating spectral intensity; and measuring the normalized penetrating spectral intensities of polarized beams with different incident angles, and fitting a liquid crystal physical model through mathematical operation to solve the liquid crystal pretilt angle.

Description

Liquid crystal pretilt angle measurement system and method

Technical field

The present invention is relevant a kind of optical measurement technology, refers in particular to a kind of measurement system and method that measures liquid crystal pretilt angle.

Background technology

Along with flat-panel screens (flat panel display; FPD) industry is flourish day by day, and the state big factory of wainscot manufacturing constantly progresses greatly technically, in the hope of high-quality more; The technology of rapid reaction and wide viewing angle strides forward; And LCD is to utilize the optical modulation property of liquid crystal to reach the function of demonstration, so liquid crystal characteristic directly can influence the characteristic and the quality of display, like critical voltage, penetrance, contrast etc.If only liquid crystal is injected simple glass substrate, can't observe tangible optical modulation phenomenon behind the extra electric field.Therefore need on substrate, do the processing of orientation, both alignment layers is understood the Liquid Crystal Molecules Alignment (Easy Axis) on same direction of guidance surface, and then drives the motion of whole liquid crystal layer molecule, just can obtain effective optical modulation effect.Therefore, both alignment layers has influenced the quality of LCD, and one of key factor that wherein determines the both alignment layers function is the tilt angle of liquid crystal.

As shown in Figure 1, this figure is the liquid crystal pretilt angle synoptic diagram, and so-called tilt angle is the angle theta on liquid crystal molecule 10 and plane 11.Owing to fully perpendicular to panel ability directing light, therefore,, then can increase the liquid crystal needed time of angle that changes when not switching on during the liquid crystal energising if liquid crystal is to be parallel to face glass.So,,, then can accelerate the time of liquid crystal reaction if liquid crystal has a tilt angle when configuration in order to let the reaction of initial rotation accelerate.

As shown in Figure 2; Known polarisation measures the method for tilt angle; Be homogeneous (homogeneous) simple structure that liquid crystal panel 12 is regarded as not having windup-degree; Inclination measured panel 12 or polarized light luminescence unit 13 and receiving element 14 are done direct match and are found the solution to measure its penetrance corresponding tilt angle, or phase differential (Retardation) corresponding tilt angle is done direct match and found the solution.For known stable twisted nematic (Twist Nematic; TN) the polarisation method for measurement of liquid crystal pretilt angle is like United States Patent (USP) notification number US.Pat.No.6,822; Disclose them in 737 and be the basis with broad sense Jones matrix (Extended Jone ' sMatrix); Use polarization components-testing sample-phase compensator-analyzing assembly (Polarizer-Sample-Compensator-Analyzer, under framework PSCA), the inclination testing sample; And find out the relation of TN liquid crystal panel broad sense Jones matrix at incident polarization light direction and liquid crystal windup-degree, can under small angle inclination, use match to find the solution the phase differential of the liquid crystal panel that is measured.

In addition, like U.S. Pat .Pat.No.5,394,245 disclose a kind of technology that measures tilt angle, are to utilize the ratio of polarized light reflectivity logarithm in sample to find the solution liquid crystal pretilt angle.And U.S. Pat .Pat.No.a5,172,187 disclose a kind of amount of polarization photometry bundle and polarization reference light beam of utilizing, and the absorption value under the analysis different inclination angle is in the hope of tilt angle.

Summary of the invention

The object of the present invention is to provide a kind of liquid crystal pretilt angle measurement system and method.

For realizing above-mentioned purpose, in one embodiment, the present invention provides a kind of liquid crystal pretilt angle measurement system, comprising: an optical module, a rotation control unit and a signal processing unit.This optical module includes a polarized light emission module and a polarized light receiver module; Wherein this polarized light emission module can provide at least one detected light to a testing sample and penetrate light to form one, and this polarized light receiver module receives this and penetrates light and penetrate spectrum to obtain one.This rotation control unit can provide the incident angle of this object of incident that changes this detected light.This signal processing unit is connected with this Optical Receivers telecommunication, this signal processing unit be with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had.

In another embodiment, the present invention also provides a kind of liquid crystal pretilt angle measurement system, comprising: an optical module and a signal processing unit.This optical module has at least one polarized light emission module and at least one polarized light receiver module.Penetrate light to form corresponding complex trace on detected light to a testing sample that each polarized light emission module can provide complex trace to have different incidence angles; Each polarized light receiver module is corresponding with a polarized light emission module respectively, and each polarized light receiver module receives this complex trace and penetrates light to obtain penetrating about this complex trace the spectrum that penetrates of light.This signal processing unit is connected with this Optical Receivers telecommunication, this signal processing unit be with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had.

In another embodiment; The present invention also provides a kind of liquid crystal pretilt angle method for measurement; Include the following step: set up one and penetrate the spectrum simulation function; This penetrates the spectrum simulation function for the penetrating shaft angle that had about the polarization optics assembly and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal, and this mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle; One testing sample is placed between one first polarization optics assembly and the one second polarization optics assembly; Measurement is penetrated spectrum about what this liquid crystal had under different incidence angles; Penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had with what this penetrated that the match of spectrum simulation function had under should the correspondence different incidence angles.

Description of drawings

Fig. 1 is the liquid crystal pretilt angle synoptic diagram.

Fig. 2 is that known polarisation measures the tilt angle system schematic.

Fig. 3 is the liquid crystal pretilt angle measurement system first embodiment synoptic diagram of the present invention.

Fig. 4 is the liquid crystal pretilt angle measurement system second embodiment synoptic diagram of the present invention.

Fig. 5 is liquid crystal pretilt angle measurement system the 3rd an embodiment synoptic diagram of the present invention.

Fig. 6 measures the tilt angle schematic flow sheet for the present invention.

Fig. 7 A is the liquid crystal distribution schematic diagram.

Fig. 7 B is a liquid crystal sublayer optical model synoptic diagram.

Fig. 8 A penetrates the spectrum schematic flow sheet for measuring.

Fig. 8 B penetrates another embodiment schematic flow sheet of spectrum for measuring.

Fig. 9 and Figure 10 are for penetrating spectral intensity and incident angle graph of relation.

Main mark symbol in the accompanying drawing

The 10-liquid crystal molecule; The 11-plane; The 12-liquid crystal panel; 13-polarized light luminescence unit; The 14-receiving element; 2-liquid crystal pretilt angle measurement system; The 20-optical module; 21-polarized light emission module; The 210-light source; The 211-leaded light component; 212-optical fiber; 213-polarization light projector unit; 2130-optical alignment lens; The 2131-polarization components; The 214-sloping platform; 22-polarized light receiver module; 220-image spectrometer; The 221-leaded light component; 222-optical fiber; The 223-polarization is received the light unit; The 2230-condenser lens; 2231-analyzing assembly; The 23-rotation control unit; The 24-signal processing unit; 3-liquid crystal pretilt angle measurement system; The 30-optical module; 31-polarized light emission module; The 310-light source; The 311-leaded light component; 313-multi-angle light projector module; 314-polarization light projector unit; 3140-optical alignment lens; The 3141-polarization components; 32-polarized light receiver module; 320-image spectrometer; The 321-leaded light component; The 322-multi-angle is received optical module; The 323-polarization is received the light unit; The 3230-condenser lens; 3231-analyzing assembly; The 33-signal processing unit; 4-liquid crystal pretilt angle method for measurement; 40～43-step; 420～424-step; 420a～423a-step; 50,51-substrate; The 52-liquid crystal layer; 520-liquid crystal sublayer; 53,54-polarization components; The 90-testing sample; 91,93-polarization detected light; 92,94-penetrates light.

Embodiment

For further cognition and understanding being arranged to feature of the present invention, purpose and function; Following spy describes the relevant thin portion structure of device of the present invention and the theory reason of design; So that those skilled in the art can understand characteristics of the present invention, detailed description is presented below:

The invention relates to a kind of liquid crystal pretilt angle measurement system and method, can provide and measure a plurality of angles of inclination and a plurality of sample spot simultaneously.Be to utilize polarization components-testing sample-analyzing assembly (Polarizer-Sample-Analyzer on the measurement system; PSA) system architecture; After trying to achieve sample optical axis azimuth information through synchronous rotatory polarization assembly and analyzing assembly, measure vertical and horizontal polarization attitude light beam, calculate the normalization spectral intensity with vertical and horizontal polarization attitude light beam; Utilize the spectral information of sample under the different incidence angles degree, match draws the tilt angle parameter of liquid crystal.Method and system of the present invention is applicable to that wide-angle tilt measures and various liquid crystal panels.

The invention relates to a kind of liquid crystal pretilt angle measurement system and method; Be to set up state equivalence matrix, utilize this state equivalence matrix and the penetrating shaft angle of polarization components and analyzing assembly to set up about the optical model of penetrance and tilt angle with as the foundation that measures and match is found the solution about liquid crystal according to the characteristic that liquid crystal is cut apart the sublayer.

See also shown in Figure 3ly, this figure is the liquid crystal pretilt angle measurement system first embodiment synoptic diagram of the present invention.This liquid crystal pretilt angle measurement system 2 includes an optical module 20, a rotation control unit 23 and a signal processing unit 24.This optical module 20 has a polarized light emission module 21 and a polarized light receiver module 22.This polarized light emission module 21 also has a light source 210, a leaded light component 211 and a plurality of polarization light projectors unit 213.In the present embodiment, this light source 210 is a wideband white light source, but not as limit.This leaded light component 211 is a fibre bundle, and it has a plurality of optical fiber 212.These a plurality of optical fiber 212 connect with a plurality of polarization light projectors unit 213 is even mutually respectively.Because it is a plurality of that the polarization light projector unit 213 of present embodiment has, so optical fiber 212 needs a plurality of photoconduction is caused in the corresponding polarization light projector unit 213; Otherwise,, then only need an optical fiber 212 if polarization light projector unit 213 has only one.Decide according to the detection needs as for 213 of one or a plurality of polarization light projectors unit, as: single-point detecting or multiple spot detecting do not have certain restriction.

The broadband light that these leaded light component 211 optical fiber 212 capable of using are produced light source 210 is directed to corresponding polarization light projector unit 213.Each polarization light projector unit 213 is set up on the sloping platform 214.This sloping platform 214 is to be connected with rotation control unit 23 telecommunications, changes the platform inclination angle with the controlling signal that receives rotation control unit 23, and then changes the incident angle of the polarization detected light that this polarization light projector unit 213 projected.Polarization light projector unit 213 is by optical alignment lens (Collimation Lens) 2130 or collimation lens set and 2131 formations of polarization components; Broadband light collimation and polarization that polarization light projector unit 213 purposes are mainly guided optical fiber; Make projecting beam form the parallel detected light 91 of a tool linear polarization and be projected on the testing sample 90, the testing sample 90 of present embodiment is a liquid crystal material.This polarization detected light 91 is passed 90 formation one of this testing sample and is penetrated light 92.

This polarized light receiver module 22 also has an image spectrometer 220, a leaded light component 221 and a plurality of polarization and receives light unit 223.This image spectrometer 220 can be a multichannel image spectrometer, but not as limit, is to be connected with these signal processing unit 24 telecommunications.This leaded light component 221 is to connect with these image spectrometer 220 idols.In the present embodiment, this leaded light component 221 is a fibre bundle, and it has a plurality of optical fiber 222, and light unit 223 is even mutually to be connect to receive with these a plurality of polarizations respectively.The quantity of this optical fiber 222 can be more than one or two, and its quantity is to decide according to the quantity of this polarization receipts light unit 223, and the embodiment with Fig. 3 of the present invention is not restriction.This polarization is received light unit 223 and is set up on the sloping platform 224, and this sloping platform 224 can be changed the angle that this polarization is received light unit 223 by the control of rotation control unit 23.

Polarization is received light unit 224 and is made up of with 2230 of condenser lenses (FocusingLens) an analyzing assembly (analyzer) 2231.This analyzing assembly 2231 is a linear polarization assembly.The light that penetrates through analyzing assembly 2231 focuses on the corresponding optical fiber 222 through condenser lens 2230.222 of each optical fiber are linked this image spectrometer 220.This image spectrometer 220 is transferred to this data analysis unit 24 with spectral information again.This signal processing unit 24; Be to be connected with these Optical Receivers 22 telecommunications; This signal processing unit 24 is with the multi channel spectral intensity information that penetrates of Synchronization Analysis, and with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample 90 is had.In addition; Though being the angle that polarized luminescence module 21 and the polarization of control in the light emitting module 20 received light unit 22, the spinning movement of the embodiment of Fig. 3 changes; But; In another embodiment, can rotate to change the angle of incident detected light by the platform of rotation control unit 23 control carrying testing samples 90.

As shown in Figure 4, this figure system is the liquid crystal pretilt angle measurement system second embodiment synoptic diagram of the present invention.In the present embodiment, this system 3 includes an optical module 30 and a signal processing unit 33.This optical module 30 includes a polarized light emission module 31 and a polarized light receiver module 32.Penetrate light 94 to form corresponding complex trace on detected light 93 to the testing sample 90 that this polarized light emission module 31 can provide complex trace to have different incidence angles.This polarized light emission module 31 has a light source 310, a leaded light component 311 and a multi-angle light projector module 313.In the present embodiment, this light source 310 and this leaded light component 311 are said with leaded light component 211 like the light source 210 of Fig. 3, do not give unnecessary details at this.The multi-angle light projector module 313 of present embodiment has a plurality of polarization light projectors unit 314, and each polarization light projector unit 314 has an angle theta with the optical axis of adjacent polarization light projector unit 314 _pMake this polarized light emission module 31 that the polarization detected light 93 of different incidence angles degree can be provided simultaneously.The angular range that this polarization light projector unit 314 is distributed can be between 90 degree to-90 degree, but not as limit.And the angle theta that adjacent polarization light projector unit 314 is had _pThen can decide as required.Under identical angular range, if θ _pMore little, then polarization light projector unit 314 numbers of representative configuration are many more.Have optical alignment lens 3140 and polarization components 3141 too as for each polarization light projector unit 314.The polarization detected light 93 that the complex trace that this polarized light emission module 31 projects has a different incidence angles penetrates light 94 through this testing sample 90 with what form the different emergence angle of complex trace.

This polarized light receiver module 32 has an image spectrometer 320, a leaded light component 321 and a multi-angle and receives optical module 322.The effect of this image spectrometer 320 and this leaded light component 321 is not given unnecessary details at this with of image spectrometer 220 and the leaded light component 221 of Fig. 3.It is to have a plurality of polarizations to receive light unit 323 that this multi-angle is received optical module 322, and it is corresponding with this a plurality of polarization light projectors unit 314 respectively, and each polarization is received light unit 323 and had an analyzing assembly 3231 and a condenser lens 3230.And adjacent polarization is received the optical axis of 323 of light unit and is had an angle.In the present embodiment, to receive light unit 323 be to receive the polarization detected light of being launched via the polarization light projector unit 314 of correspondence through the formed light 94 that penetrates of testing sample, this image spectrometer 320 that transmits via leaded light component 321 again for each polarization.This signal processing unit 33 is connected with these polarized light receiver module 32 telecommunications, this signal processing unit 33 be with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample 90 is had.See also shown in Figure 5ly, this figure is liquid crystal pretilt angle measurement system the 3rd an embodiment synoptic diagram of the present invention.The framework of present embodiment is similar with Fig. 4 basically; Difference be polarized light emission module 31 and a polarized light receiver module 32 of present embodiment be utilize respectively a plurality of a plurality of multi-angle light projector modules 313 and multi-angles like figure four receive optical module 322 respectively correspondence be laid on the different detection position, with simultaneously to a plurality of positions and carry out multi-angle penetrate the spectrum detecting.

Next explanation utilizes first three tilt angle measurement system of the present invention to measure the liquid crystal pretilt angle method of testing sample.See also shown in Figure 6ly, this figure is that the present invention measures the tilt angle schematic flow sheet.This method 4 is at first set up one with step 40 and is penetrated the spectrum simulation function; This penetrates spectrum simulation function system for the penetrating shaft angle that had about the polarization optics assembly and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal, and this mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle.

Below the mode that this penetrates the spectrum simulation function is set up in explanation, and shown in Fig. 7 A and Fig. 7 B, wherein Fig. 7 A is the liquid crystal distribution schematic diagram; Fig. 7 B is a liquid crystal sublayer optical model synoptic diagram.Be distributed with a liquid crystal layer 52 substrate 50 and 51, its thickness is Z.With this liquid crystal layer 52 layerings plural number liquid crystal layer 520, and set up the model of describing this liquid crystal layer, shown in (1), for liquid crystal layer 52 being divided into the equivalent matrix representation formula behind N the liquid crystal sublayer 520 with this plural number liquid crystal layer.

Wherein, N represents the quantity of liquid crystal sublayer, and

represents the torsion angle of liquid crystal.And R is the rotation of coordinate matrix, and it can be expressed as suc as formula shown in (2).

W _jShown in (3), on behalf of the Jones matrix (Jones Matrix) of the liquid crystal phase potential difference of each liquid crystal sublayer 520, it represent.At W _jIn, δ _{O, j}And δ _{E, j}Can also be expressed as suc as formula shown in (4), wherein Δ z represents the thickness of each liquid crystal sublayer 520, and the λ in the formula (4) is the detecting light wavelength, and n ' _{O, j}And n ' _{E, j}Be respectively in the detected light 91 ordinary light (ordinary ray) composition and and extraordinary ray (extraordinary ray) composition, the equivalent refractive index in the liquid crystal sublayer respectively, it can be expressed as respectively suc as formula shown in (5).

$W_j=\left(\begin{array}{cc}{e}^{{\mathrm{i\&delta;}}_{e,\mathrm{<figure-callout\; id="0"\; label="j"\; filenames="H2009102210569E00111.png,H2009102210569E00121.png"\; state="\{\{state\}\}">j</figure-callout>}}}& 0\\ 0& e^{{\mathrm{i\&delta;}}_{o,j}}\end{array}\right)...\left(3\right)$

${\mathrm{\&delta;}}_{o,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{o,j}\mathrm{\&Delta;z}$ ${\mathrm{\&delta;}}_{e,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{e,j}\mathrm{\&Delta;z}...\left(4\right)$

${n^{\&prime;}}_{o,j}=\sqrt{n_o^2-X^2}$

${n^{\&prime;}}_{e,j}=-\frac{{\mathrm{\&epsiv;}}_{\mathrm{xz},j}}{{\mathrm{\&epsiv;}}_{\mathrm{zz},j}}X+\sqrt{\frac{{n_e}^2{n_o}^2}{{\mathrm{\&epsiv;}}_{\mathrm{zz},j}}-\frac{{\mathrm{\&epsiv;}}_{\mathrm{xx},j}{\mathrm{\&epsiv;}}_{\mathrm{zz},j}-{\mathrm{\&epsiv;}}_{\mathrm{xz},\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2009102210569E00031.png"\; state="\{\{state\}\}">j</figure-callout>}}^2}{{\mathrm{\&epsiv;}}_{\mathrm{zz},j}^2}{X}^2}...\left(5\right)$

In formula (5), X=sin θ _k, θ wherein _kRepresent the incident angle of the polarization detected light of incident.And the ε in the formula (5) _Xx, ε _ZzWith ε _XzThen be expressed as respectively suc as formula shown in (6).

${\mathrm{\&epsiv;}}_{\mathrm{zz},j}=n_o^2+(n_e^2-n_o^2){\sin }^2{\mathrm{\&theta;}}_{\mathrm{LC},j}$

${\mathrm{\&epsiv;}}_{\mathrm{xx},j}={\mathrm{<figure-callout\; id="2"\; label="n\; o"\; filenames="H2009102210569E00031.png"\; state="\{\{state\}\}">n</figure-callout>}}_o^{}+(n_e^2-n_o^2){\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="H2009102210569E00031.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2{\mathrm{\&theta;}}_{\mathrm{LC},\mathrm{<figure-callout\; id="2"\; label="j\; cos"\; filenames="H2009102210569E00031.png"\; state="\{\{state\}\}">j</figure-callout>}}{\cos }^{}{}^2{\mathrm{\&phi;}}_{\mathrm{LC},j}...\left(6\right)$

${\mathrm{\&epsiv;}}_{\mathrm{xz},j}=(n_e^2-n_o^2)\sin {\mathrm{\&theta;}}_{\mathrm{LC},j}\cos {\mathrm{\&theta;}}_{\mathrm{LC},j}\cos {\mathrm{\&phi;}}_{\mathrm{LC},j}$

In formula (6), θ _{LC, j}Be the tilt angle of liquid crystal sublayer 520, and φ _{LC, j}Position angle for liquid crystal sublayer 52.n _oAnd n _eBe respectively ordinary light (ordinary ray) composition and and extraordinary ray (extraordinary ray) composition, the refractive index in liquid crystal sublayer 520 respectively in the detected light 91.

Under the framework of the PSA of Fig. 7 A; Because liquid crystal layer 52 is to be arranged between two linear polarization assemblies 53 and 54; Wherein linear polarization assembly 53 has the penetrating shaft angle [alpha] that allows light to pass through, and its penetrating shaft angle of linear polarization assembly 54 (for analyzing assembly (analyzer)) is γ.Therefore, the normalized spectrum simulation function that penetrates can be expressed as suc as formula shown in (7).

$T={\left|\begin{array}{c}\left(\begin{array}{cc}\cos \mathrm{\&gamma;}& \sin \mathrm{\&gamma;}\end{array}\right)W_{\mathrm{cell}}\left(\begin{array}{c}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\end{array}\right)\end{array}\right|}^2...\left(7\right)$

According to the expression of formula (1)～(6), that can learn formula (7) penetrates the spectrum simulation function for the penetrating shaft angle that had about linear polarization assembly 53 and 54 and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal.This mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle.

Set up this and penetrate after the spectrum simulation function, return shown in Figure 6ly, then carry out step 41 testing sample (also being liquid crystal to be measured) is arranged between one first polarization optics assembly and the one second polarization optics assembly.With Fig. 3 is example, and this testing sample 90 is arranged at the polarization components 2131 and the polarization of polarization light projector unit 214 and receives between the polarization components 2231 of light unit 223.Then carry out step 42, measure about what testing sample was had under different incidence angles and penetrate spectrum.See also shown in Fig. 8 A, this figure measures to penetrate the spectrum schematic flow sheet.The flow process of Fig. 8 A is to explain with the measurement system of Fig. 3, and this penetrates the spectrum measuring method and includes the following step: provide the detected light with an incident angle through this polarization components 2131, this testing sample 90 and this analyzing assembly 2231 with step 420 earlier.As shown in Figure 3, in this step, mainly be that the polarization detected light 91 of utilizing polarization light projector unit 213 to produce penetrates this testing sample 90 and received light unit 223 by polarization and receives.Get back to shown in Fig. 8 A, then make this polarization components 2131 and one first angle and one second angle that this analyzing assembly 2231 has with respect to this testing sample optical axis penetrate spectrum respectively to obtain one first with step 421.In this step 421; Mainly be with the optical axis of the testing sample 214 reference zero angle of coordinate as a reference; And the penetrating shaft angle of the penetrating shaft angle of while rotatory polarization assembly 2131 and analyzing assembly 2231 is with respect to the angle of sample 90 optical axises; It is respectively α angle and γ angle, and the spectral intensity that penetrates that this moment, image spectrometer 220 measured is distributed as S _p

Then, carry out step 422, make this polarization components 2131 and an angular and one the 4th angle that this analyzing assembly 2231 has with respect to this testing sample 90 optical axises penetrate spectrum respectively to obtain one second.In this step, mainly be to utilize the penetrating shaft angle of penetrating shaft angle and the analyzing assembly 2231 of rotatory polarization assembly 2131 to be respectively α angle and (γ+90) angle with respect to the sample optical axis, the spectral intensity that penetrates that this moment, image spectrometer 220 measured is distributed as S _sThen with step 423 this first is penetrated spectrum and this second and penetrate spectrum and carry out the normalization calculation and penetrate spectrum to obtain normalization again.In this step, mainly be with the testing sample signal S that measures _pAnd S _sBring equation (8) into, penetrate spectral intensity T with calculating normalization _p(λ) and T _s(λ).Can select T as for the normalized spectral intensity that penetrates _p(λ) or T _s(λ) as representative, present embodiment is with T _s(λ) as the representative of normalization spectral intensity.

$T_p\left(\mathrm{\&lambda;}\right)=\frac{S_p}{S_p+S_s},$ $T_s\left(\mathrm{\&lambda;}\right)=\frac{S_s}{S_s+S_p}...\left(8\right)$

Because abovementioned steps 420 to step 423 is to single incident detected light, therefore also must be by the angle of rotatory polarization light projector unit 213, to change the incident angle of polarization detected light.So, after step 423, can carry out step 424, change the angle of this incident angle and repeat preceding four steps to obtain being penetrated spectrum under different incidence angles, to form result as shown in Figure 9 about what this liquid crystal had.In Fig. 9, transverse axis is represented the different incidence angles degree, and the longitudinal axis is measured when then representing corresponding different incidence angles to spend penetrates spectral intensity.

Aforesaid mode is for the system measurements of utilizing Fig. 3 penetrates spectrum, and then explanation utilizes the mode of Fig. 4 or Fig. 5 to measure and penetrates spectrum.See also shown in Fig. 8 B, in the measurement step of present embodiment, the detected light that at first provides complex trace to have different incidence angles respectively with step 420a is passed through this polarization components 3141, this testing sample 90 and this analyzing assembly 3231.Make this polarization components 3141 and one first angle and one second angle that this analyzing assembly 3231 has with respect to this testing sample 90 optical axises penetrate spectrum respectively with step 421a then to obtain a plurality of first.Because in the embodiment of Fig. 4 or Fig. 5; Be to have a plurality of polarization light projector unit 213 that different incidence angles can be provided; Therefore can produce the polarization detected light 93 of different incidence angles simultaneously; Penetrate light 94 through testing sample formation after 90s, received optical module by a plurality of polarizations simultaneously again and receive, therefore can be according to the spectral intensity that penetrates that light obtains a plurality of correspondences that penetrates that is received.And first angle and second angle are respectively the penetrating shaft angle of penetrating shaft angle and analyzing assembly 2231 of polarization components 2131 with respect to the angle of sample optical axis, and it is divided into α angle and γ angle, and the spectral intensity that penetrates that this moment, spectrometer measured is distributed as S _pThen carry out step 422a, make this polarization components 3141 and an angular and one the 4th angle that this analyzing assembly 3231 has with respect to this testing sample 90 optical axises penetrate spectrum respectively to obtain a plurality of second.This angular and the 4th angle are meant that the penetrating shaft angle of penetrating shaft angle and analyzing assembly 3231 of polarization components 3141 is with respect to the angle of sample optical axis; It is respectively α angle and (γ+90) angle, and the spectral intensity that penetrates that this moment, spectrometer measured is distributed as S _sAt last, with step 423a this a plurality of first is penetrated spectrum and this a plurality of second and penetrate spectrum and carry out the normalization calculation and penetrate spectrum with the normalization that obtains a plurality of corresponding different incidence angles again.

Return shown in Figure 6; After obtaining the relation information of spectral intensity and incident angle; Utilize step 43 at last again, penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had with what this penetrated that the match of spectrum simulation function had under should the correspondence different incidence angles.See also shown in the formula (7); The normalized spectral theory value that penetrates of T representative of formula (7); And according to can learning in formula (1), (3), (4), (5) and (6), the T value in the formula (7) is that the angle of penetration of α and analyzing assembly is under the situation of γ in the angle of penetration of polarization components, is θ _{LC, j}The function of (tilt angle).Therefore, can utilize the mode of formula (7), come the curve of fitted figure 9, can learn that according to the result of match formula (7) is at θ with the function match _{LC, j}When tilt angle=3.95 were spent, the curve of resulting curve and Fig. 9 was pressed close to most, and the tilt angle that therefore can obtain testing sample is 3.95 degree.In addition, shown in figure 10, this figure is that testing sample is parallel orientation (Homogeneous) liquid crystal panel measurement synoptic diagram.Based on the result of match, its tilt angle is 6.03 degree.

The above is merely embodiments of the invention, when not limiting the scope of the invention with this.The equalization of promptly doing according to claim of the present invention generally changes and modifies, and will not lose main idea of the present invention place, does not also break away from the spirit and scope of the present invention, and the former capital should be regarded as further enforcement situation of the present invention.

Claims (21)

1. liquid crystal pretilt angle measurement system comprises:

One optical module includes;

One polarized light emission module can provide at least one detected light to a testing sample and penetrate light to form one; And

One polarized light receiver module receives this and penetrates light and penetrate spectrum to obtain one;

One rotation control unit can provide the incident angle of this object of incident that changes this detected light; And

One signal processing unit; Be connected with this polarized light receiver module telecommunication; This signal processing unit be with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had; This penetrates the spectrum simulation function for the penetrating shaft angle that had about the polarization optics assembly and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal, and this mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle;

The said spectrum simulation function representation that penetrates is:

$T={\left|\left(\begin{array}{cc}\cos \mathrm{\&gamma;}& \sin \mathrm{\&gamma;}\end{array}\right)W_{\mathrm{cell}}\left(\begin{array}{c}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\end{array}\right)\right|}^2,$

Wherein, α, γ are the penetrating shaft angle that the polarization optics assembly is had, W _CellFor utilizing the mesomorphic state matrix of a plurality of liquid crystal sublayer institute match about the optical characteristics of liquid crystal:

Wherein, N represents the quantity of liquid crystal sublayer; represents the torsion angle of liquid crystal,

R be the rotation of coordinate matrix:

W _jJones's function for the liquid crystal phase potential difference of each liquid crystal sublayer is expressed as:

$W_j=\left(\begin{array}{cc}{e}^{i{\mathrm{\&delta;}}_{e,j}}& 0\\ 0& e^{i{\mathrm{\&delta;}}_{o,j}}\end{array}\right),$

Wherein, ${\mathrm{\&delta;}}_{o,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{o,j}\mathrm{\&Delta;\; z},$ ${\mathrm{\&delta;}}_{e,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{e,j}\mathrm{\&Delta;\; z},$ λ is this detecting light wavelength, and Δ z represents the thickness of each liquid crystal sublayer, n ' _{O, j}And n ' _{E, j}Be respectively ordinary light composition and extraordinary ray composition in this detected light, respectively the equivalent refractive index in the liquid crystal sublayer:

${n^{\&prime;}}_{e,j}=-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}X+\sqrt{\frac{{n_e}^2{n_o}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xx},j}{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}-{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}^2}{X}^2},$ X=sin θ _k, θ _kRepresent the incident angle of this detected light, ${\mathrm{\&epsiv;}}_{\mathrm{Zz},j}=n_o^2+(n_e^2-n_o^2){\mathrm{Sin}}^2{\mathrm{\&theta;}}_{\mathrm{LC},j},$

n _oAnd n _eBe respectively ordinary light composition and the extraordinary ray composition refractive index in the liquid crystal sublayer respectively in this detected light, θ _{LC, j}Be the tilt angle of liquid crystal sublayer,

Position angle for the liquid crystal sublayer.

2. liquid crystal pretilt angle measurement system as claimed in claim 1, wherein, this rotation control unit can provide the angle that changes this testing sample or this optical module.

3. liquid crystal pretilt angle measurement system as claimed in claim 1, wherein, this polarized light emission module has:

One light source;

One leaded light component connects with this light source mutually by chance; And

At least one polarization light projector unit connects with this leaded light component, so that the detected light that this light source was produced is projected on this testing sample mutually by chance.

4. liquid crystal pretilt angle measurement system as claimed in claim 3, wherein, this leaded light component is a fibre bundle, includes at least one optical fiber.

5. liquid crystal pretilt angle measurement system as claimed in claim 3, wherein, this polarization light projector unit is to be made up of collimation lens or collimation lens set and a polarization components.

6. liquid crystal pretilt angle measurement system as claimed in claim 1, wherein, this polarized light receiver module has:

One image spectrometer is connected with this signal processing unit telecommunication;

One leaded light component connects with this image spectrometer idol; And

At least one polarization is received the light unit, connects by chance mutually with this leaded light component, causes this leaded light component this is penetrated photoconduction.

7. liquid crystal pretilt angle measurement system as claimed in claim 6, wherein, this leaded light component is a fibre bundle, includes at least one optical fiber.

8. liquid crystal pretilt angle measurement system as claimed in claim 6, wherein, it is by collimation lens and a polarization components that this polarization is received light unit, or collimation lens set and a polarization components constitute.

9. liquid crystal pretilt angle measurement system comprises:

One optical module includes;

Penetrate light to form corresponding complex trace on detected light to a testing sample that at least one polarized light emission module, each polarized light emission module can provide complex trace to have different incidence angles; And

At least one polarized light receiver module, corresponding with this at least one polarized light emission module respectively, each polarized light receiver module receives this complex trace and penetrates light to obtain penetrating about this complex trace the spectrum that penetrates of light; And

One signal processing unit; Be connected with this at least one polarized light receiver module telecommunication; This signal processing unit be with one penetrate that the match of spectrum simulation function had under should the correspondence different incidence angles penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had; This penetrates the spectrum simulation function for the penetrating shaft angle that had about the polarization optics assembly and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal, and this mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle;

The said spectrum simulation function representation that penetrates is:

$T={\left|\left(\begin{array}{cc}\cos \mathrm{\&gamma;}& \sin \mathrm{\&gamma;}\end{array}\right)W_{\mathrm{cell}}\left(\begin{array}{c}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\end{array}\right)\right|}^2,$

Wherein, α, γ are the penetrating shaft angle that the polarization optics assembly is had, W _CellFor utilizing the mesomorphic state matrix of a plurality of liquid crystal sublayer institute match about the optical characteristics of liquid crystal:

Wherein, N represents the quantity of liquid crystal sublayer;

represents the torsion angle of liquid crystal,

R be the rotation of coordinate matrix:

W _jJones's function for the liquid crystal phase potential difference of each liquid crystal sublayer is expressed as:

$W_j=\left(\begin{array}{cc}{e}^{i{\mathrm{\&delta;}}_{e,j}}& 0\\ 0& e^{i{\mathrm{\&delta;}}_{o,j}}\end{array}\right),$

Wherein, ${\mathrm{\&delta;}}_{o,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{o,j}\mathrm{\&Delta;\; z},$ ${\mathrm{\&delta;}}_{e,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{e,j}\mathrm{\&Delta;\; z},$ λ is this detecting light wavelength, and Δ z represents the thickness of each liquid crystal sublayer, n ' _{O, j}And n ' _{O, j}Be respectively ordinary light composition and extraordinary ray composition in this detected light, respectively the equivalent refractive index in the liquid crystal sublayer:

${n^{\&prime;}}_{e,j}=-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}X+\sqrt{\frac{{n_e}^2{n_o}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xx},j}{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}-{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}^2}{X}^2},$ X=sin θ _k, θ _kRepresent the incident angle of this detected light, ${\mathrm{\&epsiv;}}_{\mathrm{Zz},j}=n_o^2+(n_e^2-n_o^2){\mathrm{Sin}}^2{\mathrm{\&theta;}}_{\mathrm{LC},j},$

n _oAnd n _eBe respectively ordinary light composition and the extraordinary ray composition refractive index in the liquid crystal sublayer respectively in this detected light, θ _{LC, j}Be the tilt angle of liquid crystal sublayer, Position angle for the liquid crystal sublayer.

10. liquid crystal pretilt angle measurement system as claimed in claim 9, wherein, each polarized light emission module has:

One light source;

One leaded light component connects with this light source mutually by chance; And

A plurality of polarization light projectors unit connects with this leaded light component respectively mutually by chance, and the detected light that has different incidence angles with projection is to this testing sample, and the optical axis of each polarization light projector unit and adjacent polarization light projector unit has an angle.

11. liquid crystal pretilt angle measurement system as claimed in claim 10, wherein, this leaded light component is a fibre bundle.

12. liquid crystal pretilt angle measurement system as claimed in claim 10, wherein, each polarization light projector unit is to be made up of collimation lens and a polarization components.

13. liquid crystal pretilt angle measurement system as claimed in claim 9, wherein, each polarized light receiver module has:

One image spectrometer is connected with this signal processing unit telecommunication;

A plurality of polarizations are received the light unit, receive this complex trace and penetrate light, and the optical axis that each polarization receipts light unit and adjacent polarization are received the light unit has an angle; And

One leaded light component is received the light unit with this image spectrometer and this a plurality of polarizations respectively and is connect by chance mutually, and this leaded light component penetrates photoconduction with this complex trace and causes this image spectrometer.

14. liquid crystal pretilt angle measurement system as claimed in claim 13, wherein, this leaded light component is a fibre bundle.

15. liquid crystal pretilt angle measurement system as claimed in claim 13, wherein, it is by collimation lens and a polarization components that each polarization is received light unit, or collimation lens set and a polarization components constitute.

16. a liquid crystal pretilt angle method for measurement includes the following step:

Set up one and penetrate the spectrum simulation function; This penetrates the spectrum simulation function for the penetrating shaft angle that had about the polarization optics assembly and utilize the relation function of a plurality of liquid crystal sublayer institute match about a mesomorphic state matrix of the optical characteristics of liquid crystal, and this mesomorphic state matrix is the relational matrix about liquid crystal pretilt angle;

One testing sample is placed between the first polarization optics assembly and the one second polarization optics assembly;

Measurement is penetrated spectrum about what this liquid crystal had under different incidence angles; And

Penetrate spectrum to obtain the liquid crystal pretilt angle that this testing sample is had with what this penetrated that the match of spectrum simulation function had under should the correspondence different incidence angles;

The said spectrum simulation function representation that penetrates is:

$T={\left|\left(\begin{array}{cc}\cos \mathrm{\&gamma;}& \sin \mathrm{\&gamma;}\end{array}\right)W_{\mathrm{cell}}\left(\begin{array}{c}\cos \mathrm{\&alpha;}\\ \sin \mathrm{\&alpha;}\end{array}\right)\right|}^2,$

Wherein, α, γ are the penetrating shaft angle that the polarization optics assembly is had, W _CellFor utilizing the mesomorphic state matrix of a plurality of liquid crystal sublayer institute match about the optical characteristics of liquid crystal:

Wherein, N represents the quantity of liquid crystal sublayer;

represents the torsion angle of liquid crystal,

R be the rotation of coordinate matrix:

W _jJones's function for the liquid crystal phase potential difference of each liquid crystal sublayer is expressed as:

$W_j=\left(\begin{array}{cc}{e}^{i{\mathrm{\&delta;}}_{e,j}}& 0\\ 0& e^{i{\mathrm{\&delta;}}_{o,j}}\end{array}\right),$

Wherein, ${\mathrm{\&delta;}}_{o,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{o,j}\mathrm{\&Delta;\; z},$ ${\mathrm{\&delta;}}_{e,j}=\frac{2\mathrm{\&pi;}}{\mathrm{\&lambda;}}{n^{\&prime;}}_{e,j}\mathrm{\&Delta;\; z},$ λ is this detecting light wavelength, and Δ z represents the thickness of each liquid crystal sublayer, n ' _{O, j}And n ' _{E, j}Be respectively ordinary light composition and extraordinary ray composition in this detected light, respectively the equivalent refractive index in the liquid crystal sublayer:

${n^{\&prime;}}_{e,j}=-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}X+\sqrt{\frac{{n_e}^2{n_o}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}}-\frac{{\mathrm{\&epsiv;}}_{\mathrm{Xx},j}{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}-{\mathrm{\&epsiv;}}_{\mathrm{Xz},j}^2}{{\mathrm{\&epsiv;}}_{\mathrm{Zz},j}^2}{X}^2},$ X=sin θ _k, θ _kRepresent the incident angle of this detected light, ${\mathrm{\&epsiv;}}_{\mathrm{Zz},j}=n_o^2+(n_e^2-n_o^2){\mathrm{Sin}}^2{\mathrm{\&theta;}}_{\mathrm{LC},j},$

n _oAnd n _eBe respectively ordinary light composition and the extraordinary ray composition refractive index in the liquid crystal sublayer respectively in this detected light, θ _{LC, j}Be the tilt angle of liquid crystal sublayer,

Position angle for the liquid crystal sublayer.

17. liquid crystal pretilt angle method for measurement as claimed in claim 16 wherein, measures this and penetrates spectrum and include the following step:

Provide detected light through this polarization components, this testing sample and this analyzing assembly with an incident angle;

One first angle and one second angle that this polarization components and this analyzing assembly are had with respect to this testing sample optical axis penetrate spectrum to obtain one first;

An angular and one the 4th angle that this polarization components and this analyzing assembly are had with respect to this testing sample optical axis penetrate spectrum to obtain one second;

This first is penetrated spectrum and this second and penetrate spectrum and carry out the normalization calculation and penetrate spectrum to obtain a normalization; And

Change the angle of this incident angle and repeat preceding four steps to obtain being penetrated spectrum under different incidence angles about what this liquid crystal had.

18. liquid crystal pretilt angle method for measurement as claimed in claim 17, wherein, first angle is identical angle with angular, and second angle and the 4th angle differ 90 degree.

19. liquid crystal pretilt angle method for measurement as claimed in claim 16 wherein, measures this and penetrates spectrum and include the following step:

The detected light that provides complex trace to have different incidence angles is respectively passed through this polarization components, this testing sample and this analyzing assembly;

One first angle and one second angle that this polarization components and this analyzing assembly are had with respect to this testing sample optical axis penetrate spectrum to obtain a plurality of first;

An angular and one the 4th angle that this polarization components and this analyzing assembly are had with respect to this testing sample optical axis penetrate spectrum to obtain a plurality of second; And

This a plurality of first is penetrated spectrum and this a plurality of second and penetrate spectrum and carry out the normalization calculation and penetrate spectrum with the normalization that obtains a plurality of corresponding different incidence angles.

20. liquid crystal pretilt angle method for measurement as claimed in claim 19, wherein, first angle is identical angle with angular, and second angle and the 4th angle differ 90 degree.

21. liquid crystal pretilt angle method for measurement as claimed in claim 16, wherein, including provides pre-dumping angular range, liquid crystal windup-degree and about one of a fast and slow axis refractive index that this testing sample had step.

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