CN203688946U - Electronic control liquid crystal tunable optical filter - Google Patents
Electronic control liquid crystal tunable optical filter Download PDFInfo
- Publication number
- CN203688946U CN203688946U CN201420055592.2U CN201420055592U CN203688946U CN 203688946 U CN203688946 U CN 203688946U CN 201420055592 U CN201420055592 U CN 201420055592U CN 203688946 U CN203688946 U CN 203688946U
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- optical filter
- controlled
- wave plate
- crystal wave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The utility model provides an electronic control liquid crystal tunable optical filter. The electronic control liquid crystal tunable optical filter comprises a liquid crystal tunable optical filter body and a driving controller. The liquid crystal tunable optical filter body is of a multi-stage cascading structure. Polarizing sheets, electronic control liquid crystal wave plates and fixed phase retardance sheets are sequentially arranged in a parallel mode and stacked in an alternating mode, so that multiple stages are formed, and the fixed phase retardance sheets can be arranged in the first stage or not. The transmitting polarized light directions of all the polarizing sheets are parallel, and an angle formed between the fast axis directions of the electronic control liquid crystal wave plates and the transmitting polarized light directions of all the polarizing sheets is 45 degrees. The electronic control liquid crystal wave plates of each stage structure are controlled by the driving controller, and alternating current overvoltage drive signals of different amplitudes are loaded. The electronic control liquid crystal tunable optical filter has the advantages of fast spectrum scanning and imaging and can effectively increase the spectrum scanning speed and the spectrum imaging frame frequency. The application range of the electronic control liquid crystal tunable optical filter in the fields of remote sensing, medical diagnosis, environmental protection monitoring, general survey of agriculture and forestry and the like can be greatly expanded.
Description
Technical field
The utility model belongs to light spectrum image-forming technical field, is specifically related to the LCD electric-controlled adjustable optical filter for spectral scan.
Background technology
The spectrum imaging device of comparing optical filter wheel type, interfere type, color dispersion-type and acousto-optic tunable type, the spectrum imaging device based on LCD electric-controlled adjustable optical filter has the advantages such as volume is little, lightweight, low in energy consumption.But be limited to the impact of the factor such as type of drive and liquid crystal material, its spectral scan speed is slower, and light spectrum image-forming frame frequency is generally 10-20 frame/second, in the time that the clear aperture of liquid crystal adjustable optical filter is larger, adopt conventional type of drive, the response time generally can reach hundreds of millisecond.For dynamic spectrum imaging, restrict to a great extent the time that spectrum imaging system obtains spectral information, to successive image, processing brings very large difficulty, for example need to carry out the support of a series of related algorithms such as image registration, geometry correction, also the resolution to spectrum picture and withdrawing spectral information and identification are brought greater impact.Therefore, the spectral scan speed of raising liquid crystal adjustable optical filter is significant for the application of light spectrum image-forming technology.
At present, the spectrum imaging device response time that CRI company of the U.S. provides is generally at 50ms-150ms, imaging frame frequency is in 7-20 frame/second, to moving object or need that the target long period, (~ 100s) kept static in the situation that, while carrying out spectral scan imaging, spectral scan speed can cause spectrum picture fuzzy inaccurate with spectroscopic data extraction slowly, affect the result of spectrum identification, had a strong impact on the application in fields such as remote sensing, medical diagnosis, environment monitoring, agricultural generaI investigations of spectrum imaging device based on LCD electric-controlled adjustable optical filter.
Summary of the invention
The utility model provides a kind of LCD electric-controlled adjustable optical filter, adopt overvoltage drive mode, realize the rapid spectrum scanning of liquid crystal adjustable optical filter, its response time can be brought up to and be less than 20ms, corresponding light spectrum image-forming frame frequency reaches 50 frames/more than second, greatly expand the application of liquid crystal adjustable optical filter.
The technical solution of the utility model is as follows:
A kind of LCD electric-controlled adjustable optical filter, it comprises liquid crystal adjustable optical filter and driving governor.Described liquid crystal adjustable optical filter is multi-stage cascade structure, comprising: one group of electrically-controlled liquid crystal wave plate, one group of fixed bit phase retardation sheet and one group of polaroid; Described polaroid and electrically-controlled liquid crystal wave plate and fixed bit phase retardation sheet are arranged parallel to each other, interval stacks, and form multistagely, but in the first order, can arrange or not arrange fixed bit phase retardation sheet.Wherein the transmission-polarizing light direction of all polaroids is parallel to each other, the quick shaft direction of all electrically-controlled liquid crystal wave plates and all polaroid transmission-polarizing light directions angle at 45 °.Liquid crystal wave plate in every level structure is by driving governor control, and described driving governor is overvoltage drive controller, loads the interchange overvoltage drive signal of different amplitudes, V
2for the driving voltage that liquid crystal wave plate needs, V
3the overvoltage drive signal first applying, V
3>V
2., V
3amplitude range between 10-50V, V
2voltage magnitude between 0-10V.
Described electrically-controlled liquid crystal wave plate can adopt single-stage sheet or multistage, nematic liquid crystal layer and both sides symmetrically arranged alignment films, nesa coating and transparency carrier successively in the middle of single-stage sheet comprises, the alignment film rubbing direction of described nematic liquid crystal layer both sides is antiparallel, and the liquid crystal molecule in liquid crystal layer is arranged along face.Multistage is to adopt the electrically-controlled liquid crystal wave plate single-stage sheet that quantity is even number and the index-matching fluid of filling between described liquid crystal wave plate or coupling glue; Wherein said liquid crystal wave plate is fitted in adjacent mutual antiparallel mode between two, adjacent two liquid crystal wave plates taking the direction perpendicular to logical light face as axle Rotate 180 ° after laminating.
Described from above technical scheme, LCD electric-controlled adjustable optical filter of the present utility model has special voltage drives structure, if required voltage is V when in liquid crystal adjustable optical filter, each liquid crystal wave plate is normally worked
2, when it is driven, first apply a burst pulse that duration t is very short, its amplitude V
3>V
2, and then apply V
2voltage, like this, compare and directly apply V
2compare, the rising edge of liquid crystal wave plate response time is wanted much shorter, roughly suitable with the duration of burst pulse.Therefore, each liquid crystal wave plate in composition liquid crystal adjustable optical filter is adopted under the effect of driving governor to the mode of overvoltage drive, its type of drive as shown in Figure 1, adopt overvoltage drive, can realize the rapid spectrum scanning of liquid crystal adjustable optical filter, its response time can be brought up to and be less than 20ms, corresponding light spectrum image-forming frame frequency reaches 50 frames/more than second, can effectively improve spectral scan speed and the light spectrum image-forming frame frequency of liquid crystal adjustable optical filter, liquid crystal adjustable optical filter selects to see through specific spectral band-width, and suppress the light of outer other wavelength of passband, can realize spectral scan fast.
The electrically-controlled liquid crystal wave plate that the utility model adopts is simultaneously insensitive to the incident angle of light, receives effective angle can reach ± 20 °, receives effective angle large.Because two liquid crystal cells stack in the contrary mode of tilt angle, can realize the light of different angles incident is carried out to automated optical delay compensation, while being this structure of light process, off-axis effect in first liquid crystal cell is (when Off-axis-light process wave plate, the relative normal incidence of optical delay amount changes to some extent, amount of delay is larger, effective acceptance angle of wave plate is just less) substantially come by second liquid crystal cell compensation, this auto-compensation mechanism has reduced the susceptibility of liquid crystal wave plate to light off-axis angle, thereby can make its effective receiving angle enlarge markedly.The bit phase delay amount of wave plate can accurately be controlled by automatically controlled mode in addition.
LCD electric-controlled adjustable optical filter of the present utility model is compared with current liquid crystal adjustable optical filter, can realize spectral scan fast, effectively improve spectral scan speed and light spectrum image-forming frame frequency, greatly expand LCD electric-controlled adjustable optical filter in fields such as remote sensing, medical diagnosis, environment monitoring, agricultural generaI investigations.
Brief description of the drawings
Fig. 1 is overvoltage drive mode schematic diagram.
Fig. 2 is the structure of liquid crystal adjustable optical filter and drives schematic diagram.
Fig. 3 is the structural representation of single-stage liquid crystal wave plate.
Fig. 4 is the structural representation of multistage liquid crystal wave plate.
Fig. 5 is the optical system for testing figure of multistage liquid crystal wave plate.
Fig. 6 is one-level liquid crystal adjustable optical filter response time optical path schematic diagram.
Fig. 7 A is that thickness is the liquid crystal wave plate of the 4.8 mm photoelectric response time measurement result under overvoltage drive.
Fig. 7 B is that thickness is the liquid crystal wave plate of the 8.0mm photoelectric response time measurement result under overvoltage drive.
Embodiment
Below in conjunction with accompanying drawing, the utility model is done further and is described in detail.
Fig. 2 be rapid spectrum scanning liquid crystal adjustable optical filter structure of the present utility model and drive schematic diagram, demonstration be the liquid crystal adjustable optical filter of Pyatyi cascade structure, it comprises six polaroids (1,2,3,4,5,6), 5 electrically-controlled liquid crystal wave plates (7,8,9,10,11) and four fixed bit phase retardation sheets (12,13,14,15), polaroid, electrically-controlled liquid crystal wave plate and fixed bit phase retardation sheet are arranged parallel to each other successively, interval stacks, and form altogether Pyatyi, and the first order is not fixed bit phase delay sheet.Wherein the transmission-polarizing light direction of all polaroids (1,2,3,4,5,6) is parallel to each other, the quick shaft direction of all electrically-controlled liquid crystal wave plates (7,8,9,10,11) and polaroid (1,2,3,4,5,6) transmission-polarizing light direction angle at 45 °.
In every level structure, liquid crystal wave plate is by driving governor control.Fig. 2 right side is the schematic diagram that is carried in the voltage drive signals on electrically-controlled liquid crystal wave plate in the every level structure of liquid crystal adjustable optical filter, and this signal is for exchanging overvoltage drive signal, and voltage magnitude is between 0-20V, and alternative frequency is at 0.5-5KHz.Type of drive is: if the driving voltage that liquid crystal wave plate needs is V
2, when driving, first apply a burst pulse that duration t is very short, t=0-50ms, its amplitude V
3>V
2, and then apply V
2driving voltage, V
3voltage magnitude between 10-50V, V
2voltage magnitude is between 0-10V, and under the control of driving governor, every grade of liquid crystal wave plate loads the interchange overvoltage drive signal of different amplitudes, can realize the rapid spectrum scanning of liquid crystal adjustable optical filter.
Fig. 3 is electrically-controlled liquid crystal wave plate (7,8,9,10,11) structural representation, comprises glass substrate (16,17), the ITO nesa coating (18 on both sides from outside to inside, 19), transparent dottle pin (22,23) and the intermediate liquid crystal layer 24 of PI alignment films (20,21), control thickness.Wherein ITO nesa coating (18, 19) be connected with driving governor (being hyperchannel drive source) by electrode, for liquid crystal layer 24 provides electric field, the sensing of liquid crystal molecule is rotated, change electrically-controlled liquid crystal wave plate (7, 8, 9, 10, 11) phase delay, thereby control the polarization state of incident light, PI alignment films (20, 21) be coated in glass substrate (16, 17) on inside surface, through overbaking, after the PROCESS FOR TREATMENT such as friction, liquid crystal molecule in can induced liquid crystal layer 24 is arranged according to specific direction, make electrically-controlled liquid crystal wave plate there is the birefringence optics characteristic of crystal, liquid crystal layer 24 is that the perfusion nematic liquid crystal material between glass substrate forms, and the thickness of liquid crystal layer 24 is controlled by THICKNESS CONTROL dottle pin (22,23), and refractive indices n is between 0.05 ~ 0.30.The transparent dottle pin of THICKNESS CONTROL (22,23) can adopt glass fibre, glass microballoon or plastics microballon or photo spacer etc.
In the utility model, electrically-controlled liquid crystal wave plate can adopt single-stage sheet as shown in Figure 3, also can adopt multistage of multiple single-stage sheets composition, as shown in Figure 4, it adopts quantity is the electrically-controlled liquid crystal wave plate single-stage sheet of even number, it comprises 4 liquid crystal wave plates (104, 105, 106, 107), and the index-matching fluid of filling between adjacent interfaces or coupling glue (101, 102, 103), wherein second and the 4th block of fixing liquid crystal wave plate (105, 107) relative first and the 3rd block of fixing liquid crystal wave plate (104, 106) with perpendicular to logical light face (108, 109) direction is that axle has rotated 180 °, be that liquid crystal wave plate is fitted in adjacent mutual antiparallel mode between two.The multistage wave plate in wide visual field forming like this, its optical phase put-off can regulate meticulously and accurately control.
Adopt multistage, in the time of 25 DEG C of environment temperatures, using wavelength is that the continuous wave laser of 532 nm is measured bit phase delay under different angles, and measurement result shows, this multistage wave plate is within the scope of-5 ° ~+5 ° time in incident angle, and the variation of retardation can be ignored.
In addition, experimental results show that the susceptibility that the optical delay amount of multistage of the present utility model changes the angle of incident light: while using optical system for testing test light as shown in Figure 5 to change incident angle between-20 °～+ 20 °, liquid crystal wave plate retardation is with the variation of incident angle.Light source passes through successively by the polarizer, liquid crystal wave plate and analyzer after collimation lens accurate 1 is straight, then be collimated lens 2 receptions and enter spectrometer system, can accurately control by turntable the incident angle of the relative liquid crystal wave plate of incident light, here taking 4 ° as step-length, between-20 °～+ 20 °, change incident angle, obtain the transmitted spectrum under different angles, as shown in Figure 7.Can find out, change incident angle between-20 °～+ 20 ° time, transmitted spectrum changes hardly.Taking the transmission peaks at 532nm place as example, change incident angle between-20 °～+ 20 ° time, wavelength maximum offset corresponding to transmission peaks is only about 1nm, and it is very insensitive that the optical delay amount of visible liquid crystal wave plate group changes the angle of incident light.
In order to verify the validity of overvoltage drive mode of the present utility model, overvoltage drive signal loading, on single-stage liquid crystal wave plate, is measured to its response time.Its time response characteristic measurement light path as shown in Figure 6, liquid crystal wave plate provides overvoltage drive signal by driving governor, and be placed between two parallel polarizer, the wavelength of laser instrument is 632.8 nm, photodetector adopts visible light sensor part, have submicrosecond level photoelectric response speed, the photosignal of detector is sent into oscillograph recording.
Shown in Fig. 7 A and Fig. 7 B, be the photoelectric response measurement result of liquid crystal wave plate under overvoltage drive that thickness is respectively 4.8 mm and 8.0mm, perfusion SLC-9023 liquid crystal material.Can be found out by Fig. 7 A, thickness is the liquid crystal wave plate of 4.8 mm, under the routine of 5V voltage drives, the time that arrives stable state is 25 ms, adopt at 10 V, under the overvoltage drive of 3ms, the time that arrives stable state is only that 3 ~ 5 ms(voltages are comparatively suitable between 10-50V); Same, thickness is the liquid crystal wave plate of 8.0 mm, and under the routine of 2V voltage drives, the time that arrives stable state is 450 ms, adopts at 9.6 V, and under the impact of 7ms drives, the time that arrives stable state is only 7 ms.The experimental result being provided by Fig. 7 B can find out, overvoltage drive method can effectively improve the photoelectric response time of liquid crystal wave plate, thereby realizes rapid spectrum scanning and the imaging of liquid crystal adjustable optical filter.
Those skilled in the art are to be understood that; above embodiment is only non-limiting in order to the technical solution of the utility model to be described; under the aim and scope prerequisite that do not depart from the technical solution of the utility model; amendment to the technical solution of the utility model and be equal to replacement, within also all should being encompassed in the protection domain of claim of the present utility model.
Claims (4)
1. a LCD electric-controlled adjustable optical filter, comprises liquid crystal adjustable optical filter and driving governor, it is characterized in that: described liquid crystal adjustable optical filter is multi-stage cascade structure, comprising: one group of electrically-controlled liquid crystal wave plate, one group of fixed bit phase retardation sheet and one group of polaroid; Described polaroid and electrically-controlled liquid crystal wave plate and fixed bit phase retardation sheet are arranged parallel to each other successively, interval stacks, and form multistagely, but in the first order, arrange or fixed bit phase retardation sheet is not set; Wherein the transmission-polarizing light direction of all polaroids is parallel to each other, the quick shaft direction of all electrically-controlled liquid crystal wave plates and all polaroid transmission-polarizing light directions angle at 45 °; In every level structure, electrically-controlled liquid crystal wave plate is by driving governor control, and described driving governor is overvoltage drive controller, loads the interchange overvoltage drive signal of different amplitudes, V
2for the driving voltage that liquid crystal wave plate needs, V
3the overvoltage drive signal first applying, V
3>V
2., V
3amplitude range between 10-50V, V
2voltage magnitude between 0-10V.
2. LCD electric-controlled adjustable optical filter according to claim 1, it is characterized in that: the electrically-controlled liquid crystal wave plate in described LCD electric-controlled adjustable optical filter is single-stage sheet, nematic liquid crystal layer and both sides symmetrically arranged alignment films, nesa coating and transparency carrier successively in the middle of comprising, the alignment film rubbing direction of described nematic liquid crystal layer both sides is antiparallel, and the liquid crystal molecule in liquid crystal layer is arranged along face.
3. LCD electric-controlled adjustable optical filter according to claim 1, it is characterized in that: the electrically-controlled liquid crystal wave plate in described LCD electric-controlled adjustable optical filter is multistage, comprising: the electrically-controlled liquid crystal wave plate single-stage sheet that quantity is even number and the index-matching fluid of filling between described liquid crystal wave plate or coupling glue; Wherein said liquid crystal wave plate is fitted in adjacent mutual antiparallel mode between two, adjacent two liquid crystal wave plates taking the direction perpendicular to logical light face as axle Rotate 180 ° after laminating; Nematic liquid crystal layer and both sides symmetrically arranged alignment films, nesa coating and transparency carrier successively in the middle of described electrically-controlled liquid crystal wave plate single-stage sheet comprises, the alignment film rubbing direction of described nematic liquid crystal layer both sides is antiparallel, and the liquid crystal molecule in liquid crystal layer is arranged along face.
4. according to the LCD electric-controlled adjustable optical filter described in claim 2 or 3, it is characterized in that: the thickness of described liquid crystal layer is controlled by transparent dottle pin is set therein, its refractive indices
nbetween 0.05 ~ 0.30.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420055592.2U CN203688946U (en) | 2013-10-28 | 2014-01-28 | Electronic control liquid crystal tunable optical filter |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310516376 | 2013-10-28 | ||
| CN201310516376.3 | 2013-10-28 | ||
| CN201420055592.2U CN203688946U (en) | 2013-10-28 | 2014-01-28 | Electronic control liquid crystal tunable optical filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203688946U true CN203688946U (en) | 2014-07-02 |
Family
ID=50668558
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420055592.2U Expired - Fee Related CN203688946U (en) | 2013-10-28 | 2014-01-28 | Electronic control liquid crystal tunable optical filter |
| CN201410041914.2A Expired - Fee Related CN103792730B (en) | 2013-10-28 | 2014-01-28 | A kind of LCD electric-controlled adjustable optical filter of rapid spectrum scanning |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410041914.2A Expired - Fee Related CN103792730B (en) | 2013-10-28 | 2014-01-28 | A kind of LCD electric-controlled adjustable optical filter of rapid spectrum scanning |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN203688946U (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105739213A (en) * | 2016-05-10 | 2016-07-06 | 中国工程物理研究院流体物理研究所 | Liquid crystal optical phased-array angular amplifier |
| CN106483669A (en) * | 2016-12-13 | 2017-03-08 | 中国工程物理研究院流体物理研究所 | A kind of 3D of wide colour gamut shows glasses and imaging system |
| CN109324560B (en) * | 2018-12-06 | 2020-06-19 | 中国科学院国家天文台 | Liquid crystal driver, scanning control system and control method of system |
| CN113325648A (en) * | 2021-07-07 | 2021-08-31 | 台州安奇灵智能科技有限公司 | Spectral imaging system based on guest-host liquid crystal tunable filter |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6992809B1 (en) * | 2005-02-02 | 2006-01-31 | Chemimage Corporation | Multi-conjugate liquid crystal tunable filter |
| CN102135450A (en) * | 2010-01-21 | 2011-07-27 | 中国科学院西安光学精密机械研究所 | Liquid crystal tunable filter based static full stokes imaging spectropolarimeter |
| US8400574B2 (en) * | 2010-04-16 | 2013-03-19 | Chemimage Corporation | Short wave infrared multi-conjugate liquid crystal tunable filter |
| JP2013186429A (en) * | 2012-03-09 | 2013-09-19 | Sharp Corp | Display panel, and display device |
-
2014
- 2014-01-28 CN CN201420055592.2U patent/CN203688946U/en not_active Expired - Fee Related
- 2014-01-28 CN CN201410041914.2A patent/CN103792730B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN103792730A (en) | 2014-05-14 |
| CN103792730B (en) | 2016-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203688946U (en) | Electronic control liquid crystal tunable optical filter | |
| CN106525242B (en) | A kind of device can be used for sun polarization Stokes vector real-time measurement | |
| CN107131902B (en) | Calibration method for photoelastic modulator peak delay amount | |
| KR20160052592A (en) | Method and apparatus for measuring parameters of optical anisotropy | |
| CN201903325U (en) | Goos-Hanchen shift real-time measurement system | |
| US5966195A (en) | Method of determining cell thickness and twist angle parameters of liquid crystal cell | |
| CN103185665B (en) | The measuring method of birefringence element optical axis | |
| CN102607819B (en) | Full-light-field polarization aberration detection device and detection method | |
| CN102538971A (en) | Full-optical-field full-stokes parameter detection device and detection method | |
| US5434671A (en) | Birefringent member cell gap measurement method and instrument | |
| CN102566092B (en) | Method and device for measuring liquid crystal parameters | |
| CN202420680U (en) | Full-light-field all-Stokes parameter detecting device | |
| CN111220274A (en) | Light polarization state testing device and testing method thereof | |
| CN203688947U (en) | Multi-level wave plate | |
| CN107144550A (en) | A kind of utilization optical second harmonic determines the system and method for ferroelectric thin film farmland orientation | |
| CN112432904B (en) | Novel liquid crystal polarization modulator and detection method thereof | |
| Hsu et al. | Measuring the refractive index of transparent materials using high precision circular heterodyne interferometry | |
| CN112525493B (en) | Method and device for detecting optical characteristics of ferroelectric liquid crystal delayer | |
| CN105353088B (en) | Automatically controlled light-scattering material and device time domain response characteristic test method | |
| CN110595620B (en) | Light wave polarization rapid modulation imaging device and method | |
| CN202693266U (en) | Full-light-field polarization aberration detection device | |
| JP3142805B2 (en) | Liquid crystal cell parameter detection method and apparatus | |
| JP2576781B2 (en) | Method and apparatus for measuring cell gap of birefringent body | |
| CN109031737A (en) | A kind of fast-response phase delay device based on the double-deck nematic liquid crystal | |
| JP2778935B2 (en) | Method for measuring azimuthal anchoring energy of nematic liquid crystal device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140702 Termination date: 20190128 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |