CN201269949Y - Apparatus for realizing tri-dimensional imaging directly on retina - Google Patents
Apparatus for realizing tri-dimensional imaging directly on retina Download PDFInfo
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- CN201269949Y CN201269949Y CNU2008201857712U CN200820185771U CN201269949Y CN 201269949 Y CN201269949 Y CN 201269949Y CN U2008201857712 U CNU2008201857712 U CN U2008201857712U CN 200820185771 U CN200820185771 U CN 200820185771U CN 201269949 Y CN201269949 Y CN 201269949Y
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Abstract
一种直接在视网膜上实现三维立体成像的装置，它采用相干光源1照射全相位空间光调制器2，全相位空间光调制器2的出射相干光经光学系统3传播，光学系统出射光瞳8位于角膜4前，相干光依次通过角膜4、虹膜5、水晶体6，最后到达视网膜7，在视网膜7前后多个成像平面上相干光场的振幅分布由全相位空间光调制器2调制。本实用新型将二维或三维图像直接成像在视网膜上，结构简单，可以应用于虚拟现实显示、增强现实显示和眼底医学诊断。
A device for realizing three-dimensional imaging directly on the retina, which uses a coherent light source 1 to illuminate an all-phase spatial light modulator 2, and the outgoing coherent light of the all-phase spatial light modulator 2 propagates through an optical system 3, and the exit pupil of the optical system is 8 Located in front of the cornea 4 , the coherent light passes through the cornea 4 , iris 5 , lens 6 in sequence, and finally reaches the retina 7 . The utility model directly images two-dimensional or three-dimensional images on the retina, has a simple structure, and can be applied to virtual reality display, augmented reality display and fundus medical diagnosis.
Description
Technical field
The utility model relates to a kind of imaging device, especially relates to a kind of optical imaging device that utilizes coherent light direct imaging on retina.
Background technology
Traditional imaging device adopts two-dimensional screen to show static or dynamic image (for example LCD, plasma scope, the projection display etc.), the lens combination that the human visual system forms by cornea and crystalline, be imaged on the image on the two-dimensional screen on the retina once more, by further the image signal transmission on the retina being arrived brain, the human visual system can perceive the image of demonstration.
The image direct imaging then can be omitted two-dimensional screen on retina, realize that virtual reality (virtualreality) shows, augmented reality (augmented reality) shows and eyeground medical diagnosis (opticalcoherence tomography).The researchist of Washington, DC university has proposed a kind of retinal images scanister (list of references 1:Brian T.Schowengerdt, Eric J.Seibel, ' Scannedvoxel displays ', Information Display, Vol.24, No.7,2008, pp26-36), this device directly focuses on the human eye retina by the light signal of micromechanics scan mode with modulation.Because the lagging characteristics of human eye, when the row, column sweep velocity was enough high, the human visual system is complete picture of perception just.But this device needs complicated and expensive micromechanics scanister and complicated optical system, and for realizing the scanning of 3-D view, needs the row, column scanister of more speed.
Summary of the invention
Technical matters: the purpose of this utility model provides a kind of device of directly realizing three-dimensional imaging on retina, utilize the device of coherent light at retina image-forming, this device need not complicated and expensive micromechanics scanister and complicated optical system, directly imaging on retina, and can conveniently realize three-dimensional imaging.
Technical scheme: for fear of complicated and expensive micromechanics scanister and complicated optical system, the utility model provides a kind of device that utilizes coherent light directly to realize three-dimensional imaging on retina, and this device can be with two dimension or 3-D view direct imaging on retina.The technical solution adopted for the present invention to solve the technical problems is: adopt coherent source to shine full phase spatial light modulator, the outgoing coherent light of full phase spatial light modulator is propagated through optical system, before the optical system emergent pupil is positioned at cornea, coherent light is successively by cornea, iris, crystalline, arrive retina at last, the distribution of amplitudes of relevant light field is modulated by full phase spatial light modulator on a plurality of imaging planes before and after retina.
Coherent source can be plane light wave or spherical light wave.
Full phase spatial light modulator can produce virtual lens.
Optical system is the system that or a plurality of coaxial lens are formed, and can change light path by spectroscope.
Eyeball can be approximated to be one or two systems that coaxial lens are formed, and crystalline can be approximated to be the lens or the gradient-index lens of simple lens or multilayer variations in refractive index.
The light field distribution of amplitudes of a plurality of imaging planes forms the distribution of three-dimensional body spatial light field, the light field distribution of amplitudes of a plurality of imaging planes can fit to the distribution of retina curved surface light field, the light field distribution of amplitudes of a plurality of imaging planes is modulated by full phase spatial light modulator, and the PHASE DISTRIBUTION function of full phase spatial light modulator can pass through alternative manner or analytical method solving.
The coherent light of a plurality of wavelength adopts the mode of time-sharing multiplex to modulate by spatial light modulator, or the coherent light of a plurality of wavelength is realized coaxial demonstration simultaneously by spectroscope.
Spectroscope can be total-reflection type or semi-transparent semi-reflective, spectroscope can be the plane or curved surface, realize that by spectroscope virtual reality shows or augmented reality shows or the eyeground medical diagnosis.
Beneficial effect: the utility model beneficial effect is, can be on retina with two dimension or 3-D view direct imaging, and simple in structure, can realize that virtual reality shows, augmented reality shows and the eyeground medical diagnosis.This device need not complicated and expensive micromechanics scanister and complicated optical system, directly imaging on retina, and can conveniently realize three-dimensional imaging.
Description of drawings
Fig. 1 retinal imaging device synoptic diagram.
Fig. 2 retinal imaging device realizes that 3 D stereo shows synoptic diagram.
Fig. 3 retinal imaging device realizes that virtual reality shows, augmented reality shows and eyeground medical diagnosis synoptic diagram.
Have among the above figure: coherent source 1, full phase spatial light modulator 2, optical system 3, cornea 4, iris 5, crystalline 6, retina 7, optical system emergent pupil 8, first imaging plane 9, second imaging plane 10, the 3rd imaging plane 11, convex lens 12, spectroscope 13, cup hydratoid 14, chamber, back vitreum 15.
Embodiment
It shown in Fig. 1 the retinal imaging device synoptic diagram.This device mainly contains coherent source 1, full phase spatial light modulator 2 and optical system 3 and forms.For specifying the retina image-forming process, comprised simple eyeball sectional view among Fig. 1, cornea 4, iris 5, crystalline 6 and retina 7 are wherein arranged.Can list of references (list of references 1:Frank about the more detailed model of human eyes structure in the optical system
, ' Handbook of lasers and optics ', Springer, New York, 2007).Relevant source 1 can be the coherent light that gas, solid or semiconductor laser produce, and these coherent light scioptics can produce plane light wave or spherical light wave.The full phase spatial light modulator 2 of coherent source 1 direct irradiation, full phase spatial light modulator 2 can be the pure phase position modulator (phase only spatial light modulator) that transmissive type liquid crystal display, reflective LCoS display etc. have 0～2 π modulation range, can increase spectroscope when adopting reflective spatial light modulator.When adopting the plane light wave irradiation, the light field phase place of full phase spatial light modulator 2 exit planes is modulated to setting value, and distribution of amplitudes is constant, when adopting the spherical light wave irradiation, being equivalent to full phase spatial light modulator 2 carries out increasing a virtual lens again after the phase modulation (PM) (dispersing spherical light wave is concavees lens, the convergence spherical light wave is convex lens) (list of references 2:Joseph W.Goodman, ' Introduction to Fourier Optics, Third Edition ', the Electronic Industry Press, 2006), this virtual lens can be regarded the part as optical system 3 as.Coherent source 1 is gone into optics system 3 through full phase spatial light modulator 2 modulation are laggard, optical imaging system 3 can be made up of one or more coaxial lens, realize the functions such as convergent-divergent of optical imagery process, thereby make the emergent pupil size of optical system 3 consistent, avoid of the restriction of human eye pupil relevant Diffraction of Light with human eye pupil size.The propagation of coherent light in optical system 3 meets the scalar diffraction principle, propagator can adopt the operator method to calculate on the light ray propagation direction successively and try to achieve (list of references 2), for example, optical system 3 is made up of coaxial lens, and its communication process is expressed as with the operator method:
Wherein, U
0(x y) is the optical field distribution function of optical system 3 input planes, U
1(ξ η) is the optical field distribution function of output plane, and f is the focal length of lens, d
1, d
2Be the propagation distance of coherent light before and after lens.The researchist can derive the propagator of a plurality of lens combinations as required in this area.Before optical system emergent pupil 8 was positioned at cornea 4, coherent light by cornea 4, iris 5, crystalline 6, arrived retina 7 successively at last.The propagation of coherent light in eyeball meets the scalar diffraction principle, can be regarded as the optical system (list of references 1) that two coaxial lens are formed, and its communication process is expressed as with the operator method:
Wherein, U
1(ξ η) is the optical field distribution function of optical system emergent pupil 8, n
1, n
2Be respectively the refractive index of chamber vitreum 15 behind eyeball cup hydratoid 14 and the eyeball, f
1, f
2Be respectively the focal length of cornea 4 and crystalline 6, d
3Be the distance of cornea 4 to crystalline 6, d
4Be the distance of crystalline 6 to retina 7, U
2(u v) is the optical field distribution function on the plane, retina 7 position.The diopter of cornea 4 (diopter) is metastable among the human visual system, and normal person's diopter is
And the diopter of crystalline 6 is variable, and the dioptric variation range of young man can reach 14, and the dioptric variation range of the elderly is 0 (list of references 1).When crystalline 6 diopters change, the phase term in the formula (2)
Also will change.Can draw by the operator methods analyst, when crystalline 6 diopters changed, the three dimensions light field distribution of amplitudes before the retina 7 had been made convergent-divergent accordingly one time.
Formula (1) and formula (2) have provided from coherent source 1 to retina the propagator of 7 relevant light fields, preestablish light field distribution of amplitudes function F on the plane, retina 7 position (u, v)=| U
2(u, v) under | the prerequisite, can pass through alternative manner (list of references 3:J.R.Fienup, ' Phase retrievalalgorithms:a comparison ', APPLIED OPTICS, Vol.21, No.15,1982:2758-2769) or analytic method (list of references 4:T.E.Gureyev, A.Pogany, D.M.Paganin, S.W.Wilkins, ' Linear algorithms for phase retrieval in the Fresnelregion ', Optics Communications 231 (2004) 53-70) try to achieve corresponding full phase spatial light modulator 2 PHASE DISTRIBUTION function P (x, y), by full phase spatial light modulator 2 this PHASE DISTRIBUTION function of modulation P (x, y), become the predefined light field distribution of amplitudes of acquisition on retina 7, this moment, the human visual system perceived a width of cloth two dimensional image, and its each point intensity distributions is:
I(u，v)＝|U
2(u，v)|
2 (3)，
Periodic variation PHASE DISTRIBUTION function P on full phase spatial light modulator 2 (x, y), for example changing frequency is 60Hz, human eye just can perceive continuous moving image.When the diopter of crystalline 6 changes, for guarantee on retina clearly as, need correspondingly adjust the PHASE DISTRIBUTION function of full phase spatial light modulator 2 according to formula (2).
Crystalline 6 in the eyeball is optical systems of a relative complex, formula (2) adopts simple lens to be similar to, can also use the lens or gradient-index lens (the list of references 5:A.V.Goncharov and C.Dainty of multilayer variations in refractive index, ' Wide-field schematic eye models withgradient-index lens ', J.Opt.Soc.Am.A, Vol.24, No.8, August 2007) accurately be similar to, in addition, the coaxial lens combination of cornea 4 and crystalline 6 compositions can also be approximately a simple simple lens, the researcher in this field can adopt multiple approximation method to set up the coherent light propagator of eyeball.
Figure 2 shows that retinal imaging device realization 3 D stereo shows synoptic diagram, discuss, provided the optical system 3 that constitutes by simple lens 12 among the figure simultaneously for convenient.Coherent source 1 is modulated by full phase spatial light modulator 2 back each point phase places, and amplitude remains unchanged.Simple lens 12 makes the optical field distribution of full phase spatial light modulator 2 exit planes be a picture that dwindles before cornea 4.Comprise a secondary phase factor in the imaging for avoiding, can increase the convex lens (list of references 2) that a focal length equals full phase spatial light modulator 2 and simple lens 12 distances in full phase spatial light modulator 2 backs, or employing virtual lens, the quadratic phase distribution function that is about to required lens directly is added on the PHASE DISTRIBUTION function of full phase spatial light modulator 2, or adopts the relevant spherical light wave of convergent point on plane, simple lens 12 place.The researchist can also design various optical systems 3 with zoom function in this area, for example adopt a plurality of coaxial lens to increase the refractive power of optical system, can also make image position that optical system 3 becomes to dwindle in the left side or the right on plane, cornea 4 place, it is consistent with human eye pupil size in the distribution on plane, cornea 4 place only to need to satisfy relevant light field.For realizing that 3 D stereo shows, technical scheme of the present invention is, (first imaging plane 9, second imaging plane 10, the 3rd imaging plane 11 among Fig. 2 for example before and after the retina on a plurality of imaging planes, wherein the 3rd imaging plane 11 can be considered as virtual plane after being positioned at retina, when the human eye diopter changes, thereby virtual plane reach becoming true imaging plane) in the zone of setting separately, the distribution of amplitudes of light field satisfies setting value separately, is about to the discrete distribution of amplitudes for light field on a plurality of two dimensional surfaces of distribution of amplitudes of three dimensions light field; Coherent source 1 on a plurality of imaging planes realizes simultaneously that through the modulation of full phase spatial light modulator 2 distribution of amplitudes is near setting value; Carrying out the amplitude-modulated method of coherent light on a plurality of imaging planes simultaneously is, by formula (1) and the definite coherent light propagator of formula (2) from full phase spatial light modulator 2 to a plurality of imaging planes, set Modulation and Amplitude Modulation zone and distribution of amplitudes function on each imaging plane, by the PHASE DISTRIBUTION function on iteration or the full phase spatial light modulator 2 of analytical method solving, the preferred alternative manner of the present invention the steps include:
1) determines the iteration starting condition, promptly according to the 3-D view of required demonstration, the distribution of amplitudes of discretize retina 7 front and back three dimensions light fields, determine the number of retina 7 front and back imaging planes, determine the setting regions of each imaging plane, and the distribution of amplitudes function in the setting regions, determine the coherent light propagator of optical system 3 and human eye, because the diopter of people's crystallization 6 is variable, usually need to determine a virtual viewing distance according to concrete the application, the diopter of crystalline 6 is determined by this observed range, determines the initial phase of full phase spatial light modulator 2;
2) utilize the coherent light propagator, thereby calculate the light field distribution of amplitudes that the full phase spatial light modulator 2 of relevant light field propagates into first imaging plane 9, apply first imaging plane, 9 amplitude conditions, promptly in setting regions, the light field distribution of amplitudes of being calculated is revised as setting value, and other zones remain unchanged, and light field PHASE DISTRIBUTION function remains unchanged;
3) relevant light field is propagated between a plurality of imaging planes such as second imaging plane 10, the 3rd imaging plane 11 successively, and applies light field amplitude condition successively, and light field PHASE DISTRIBUTION function remains unchanged;
4) relevant light field to full phase spatial light modulator 2, and applies light field amplitude condition from last imaging plane (for example the 3rd imaging plane 11) backpropagation, and promptly the light field distribution of amplitudes is revised as even distribution, and light field PHASE DISTRIBUTION function remains unchanged;
5) loop iteration step 2)～4), until the error of the light field distribution of amplitudes of each imaging plane and setting value less than the threshold value σ that sets in advance.
In the above-mentioned iterative step, the iteration initial plane can be the exit plane of full phase spatial light modulator 2, or other imaging planes, for example first imaging plane 9, second imaging plane 10, the 3rd imaging plane 11 etc., and the order of iteration also can change, or increasing the loop iteration process to improve the speed of convergence of calculating, this area researchist can be optimized iterative process as required.
Above-mentioned iterative step is the coherent light at single wavelength, monochromatic light for a plurality of wavelength, can adopt the mode of time-sharing multiplex, it is the independent interative computation of coherent light of each wavelength, and modulate by full phase spatial light modulator 2 successively by the mode of time-sharing multiplex, adopt this method can realize the demonstration of full-color image, can also realize coaxial demonstration simultaneously by spectroscope 13 by a plurality of wavelength coherent lights, promptly be similar to colour projection system (dotted line among Fig. 3 represents that monochromatic light passes through spectroscope 13 and realizes the coaxial of the optical system formed with cornea 4 and crystalline 6), the monochromatic light of each wavelength adopts a full phase spatial light modulator 2 to modulate separately, and it is coaxial with the optical system of cornea 4 and crystalline 6 compositions to change the light path realization successively by spectroscope 13.
In the above-mentioned iterative step, the number of imaging plane, and on each imaging plane the distribution of amplitudes of light field by the decision of the three-dimensional image of required demonstration.In addition, because human eye retina 7 is curved surfaces, so the light field distribution of amplitudes that can adopt a plurality of planar imagings fits to the light field distribution of amplitudes on retina 7 curved surfaces, promptly set the required distribution of amplitudes of picture for, thereby realize the blur-free imaging on retina 7 curved surfaces in the intersection of each plane and retina 7 curved surfaces.
The human visual system only can clearly perceive the two-dimentional distribution of light intensity information on the imaging plane that overlaps with retina 7 positions, before retina 7, optical field distribution on the back imaging plane is perceived as fuzzy image, when the diopter of crystalline 6 changes, be that human eye focus point position is when changing, the three dimensions complex light field of retina 7 front and back will produce convergent-divergent thereupon, when for example focus point tends to a distant place, the optical field distribution in original retina 7 the place aheads will move to retina 7 positions, thereby be perceived as clearly as, during focus point trend near point, the optical field distribution at original retina 7 rears will move to retina 7 positions, thus be perceived as clearly as.Therefore, crystalline 6 dioptric variations cause distribution of light intensity change in information in space on the retina 7, and the image of real-world object is similar in this process and the eye-observation three dimensions, thereby makes the human visual system perceive the picture of 3 D stereo.
Realize that for retinal imaging device virtual reality shows, augmented reality shows and the synoptic diagram of eyeground medical diagnosis shown in Fig. 3.Comparing among this technical scheme and Fig. 1 has increased a spectroscope 13, and the main effect of this spectroscope 13 is the directions of propagation that change light.For realizing that virtual reality shows that spectroscope 13 can be a total-reflection type, by changing light path, can be fixed on optical system 3 on the various helmets easily; For realizing that augmented reality shows that spectroscope 13 can be a semi-transparent semi-reflective, promptly human eye can see through spectroscope 13 and watch outside real scene, can perceive virtual image by reflection again simultaneously, and two kinds of images overlap each other; For realizing the eyeground medical diagnosis, spectroscope 13 can be a semi-transparent semi-reflective, the coherent light that is full phase spatial light modulator 2 modulation is propagated and spectroscope 13 reflections through optical system 3, imaging on retina, coherent light again behind retinal reflex reverse transfer and part transmit light microscopic 13, adopt CCD or films can photograph the interference fringe of coherent light behind retinal reflex in spectroscope 13 backs.The researcher in this field can also increase a plurality of spectroscopes as required in optical system 3, spectroscope 13 can be the plane, also can be curved surface, for example spectroscope 13 can be the concave mirror that is similar to glasses, increases convex lens again thereby be equivalent to when changing light path.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2416382C1 (en) * | 2009-11-13 | 2011-04-20 | Общество с ограниченной ответственностью "АВТЭКС" | Method and apparatus for creating of stabilised images on retina |
| CN104812342A (en) * | 2012-08-24 | 2015-07-29 | Ic英赛德有限公司 | Visual aid projector |
| CN105662334A (en) * | 2016-01-18 | 2016-06-15 | 北京国承万通信息科技有限公司 | Eye optical parameter detection equipment and head-mounted display |
| CN106842572A (en) * | 2017-01-17 | 2017-06-13 | 北京铅笔视界科技有限公司 | Nearly eye holographic display system and method |
| CN106940483A (en) * | 2017-04-20 | 2017-07-11 | 杭州光粒科技有限公司 | A kind of light field display device and display methods |
| CN107293201A (en) * | 2016-04-12 | 2017-10-24 | 英济股份有限公司 | Double-image projection device |
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2008
- 2008-09-09 CN CNU2008201857712U patent/CN201269949Y/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2416382C1 (en) * | 2009-11-13 | 2011-04-20 | Общество с ограниченной ответственностью "АВТЭКС" | Method and apparatus for creating of stabilised images on retina |
| CN104812342A (en) * | 2012-08-24 | 2015-07-29 | Ic英赛德有限公司 | Visual aid projector |
| CN104812342B (en) * | 2012-08-24 | 2018-05-11 | Ic英赛德有限公司 | Vision helps projecting apparatus |
| CN105662334A (en) * | 2016-01-18 | 2016-06-15 | 北京国承万通信息科技有限公司 | Eye optical parameter detection equipment and head-mounted display |
| CN105662334B (en) * | 2016-01-18 | 2017-07-11 | 北京国承万通信息科技有限公司 | Eye optical parameter detection equipment and head mounted display |
| CN107293201A (en) * | 2016-04-12 | 2017-10-24 | 英济股份有限公司 | Double-image projection device |
| CN107293201B (en) * | 2016-04-12 | 2019-09-06 | 英济股份有限公司 | Double-image projection device |
| CN106842572A (en) * | 2017-01-17 | 2017-06-13 | 北京铅笔视界科技有限公司 | Nearly eye holographic display system and method |
| CN106940483A (en) * | 2017-04-20 | 2017-07-11 | 杭州光粒科技有限公司 | A kind of light field display device and display methods |
| CN106940483B (en) * | 2017-04-20 | 2019-08-13 | 杭州光粒科技有限公司 | A kind of light field display device and display methods |
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