OPTICAL SYSTEM AND ITS DISPLAY SYSTEM
An optical system for aberration compensation comprising an optical module and an asymmetric refractive index distribution film is disclosed. The asymmetric refractive index distribution film comprises a liquid crystal and a liquid crystalline polymer, wherein the asymmetric refractive index distribution film set on an out-light surface or an in-light surface of the optical module. A display system comprising the above-mentioned optical system and an image panel are also disclosed herein. The asymmetric refractive index distribution film of the present invention has non-uniform refractive index distribution so as to effectively compensate the aberration formed by the optical module.
This is a continuation-in-part of application Ser. No. 13/828,723, filed in Mar. 14, 2013.
FIELD OF THE INVENTIONThe present invention relates to an optical system, and more particularly to an optical system and a display system having a refractive index distribution film with non-uniform refractive index distribution.
BACKGROUND OF THE INVENTIONIn general, the principle of designing a lens is to let a traveling light produce an optical path difference (thickness*refractive-index). Since the conventional spherical lens has a thickness increases with the optical power, therefore an improved method uses a Fresnel lens to divide the thickness into a smaller periodical structure was proposed. But the manufacture of the mold for the Fresnel lens is very complicated and relatively difficult, and the optical performance has the issues of a high chromatic dispersion and low diffraction efficiency. Therefore, conventional flat lenses such as glasses lenses achieve a change of the optical path difference by changing the refractive index distribution.
Wherein, the liquid crystalline polymer has the unique birefringence feature, and thus it can be used for the design of a flat lens. Since the liquid crystalline polymer also has the properties of dielectric anisotropy, therefore the electric field distribution can be applied to manufacture an electrically tunable liquid crystal lens. However, the present liquid crystalline polymer film only has the same refractive index distribution. In other words, each position of the liquid crystalline polymer film has the same focal length. Therefore, the present liquid crystalline polymer film with the design of a single focal length cannot be used freely with other lens. Due to the liquid crystalline polymer film having the design of a single focal length, additional components are required to change the refractive index distribution of the liquid crystal lens for manufacturing the electrically controlled liquid crystal lens.
SUMMARY OF THE INVENTIONThe present invention is directed to an optical system and its display system, the asymmetric refractive index distribution film having multi-segment or gradual variation of optical power is utilized to effectively compensate the aberration formed by the optical module.
To achieve the aforementioned objective, the present invention provides an optical system with an aberration compensation function comprises an optical module and a refractive index distribution film. The optical module has a curved surface. The refractive index distribution film comprises a liquid crystal and a liquid crystalline polymer, wherein a refractive index distribution of the refractive index distribution film is asymmetric and the tilt angle of the liquid crystal of the refractive index distribution film is fixed; the refractive index distribution film is arranged on a first side or a second side of the optical module; and the refractive index distribution film is utilized to compensate the aberration generated by the optical module.
To achieve another objective, the present invention further provides a display system with an aberration compensation function comprises an optical system and an image panel. The optical system comprises a refractive index distribution film and an optical module. The refractive index distribution film comprises a liquid crystal and a liquid crystalline polymer, wherein a refractive index distribution of the refractive index distribution film is asymmetric and the tilt angle of the liquid crystal of the refractive index distribution film is fixed; the refractive index distribution film is arranged on a first side or a second side of the optical module; and the refractive index distribution film is utilized to compensate the aberration generated by the optical module. The image panel is utilized for displaying an image, wherein the image panel set on a light entrance side of the optical system, and the image light projected from the image panel passes through the optical system to a viewer's eyes.
In summation, the liquid crystalline polymer lens structure of the present invention has one or more of the following advantages:
(1) The liquid crystalline polymer film of the present invention is flexible, so that it can be used together with the lens as a simple lens sticker.
(2) The liquid crystalline polymer film of the present invention with a non-uniform refractive index distribution has the effect of correcting nearsightedness, farsightedness, presbyopia, parallax and compensating the aberration.
(3) The liquid crystalline polymer film of the present invention has a non-uniform refractive index distribution and after finishing the production, the tilt angle of the liquid crystal of the refractive index distribution film is fixed. Due to no additional electrically-controlled component is needed, the cost can be reduced substantially.
The technical characteristics, contents, advantages and effects of the present invention will be apparent with the detailed description of a preferred embodiment accompanied with related drawings as follows. The drawings are provided for the illustration, and same numerals are used to represent respective elements in the preferred embodiments. It is intended that the embodiments and drawings disclosed herein are to be considered illustrative rather than restrictive. Same numerals are used for representing same respective elements in the drawings.
With reference to
It is noteworthy that the refractive index distribution film 1 of present embodiment has a symmetric refractive index distribution in the XY-direction, and the refractive index distribution film 1 in other embodiments of the present embodiment may have an asymmetric refractive index distribution. For better understanding, the manufacturing method of a refractive index distribution film in accordance with embodiments of the present invention is described below.
With reference to
More specifically, components used for manufacturing a refractive index distribution film include a glass substrate 12, 20, a transparent electrode 14, 18, 26, alignment layer 22, 24 and an insulating layer 16. Wherein, the components used for manufacturing the refractive index distribution film are disposed on the glass substrate 12, the transparent electrode 14, the insulating layer 16, the transparent electrode 18, the glass substrate 20, the alignment layer 22, the alignment layer 24, the transparent electrode 26 and the glass substrate 28 along the Z-direction. The mixture of a liquid crystal and a liquid crystalline polymer used for forming the refractive index distribution film 1 is disposed between the alignment layer 22 and the alignment layer 24. Wherein, the transparent electrode 18 is designed as a circular electrode layer; the transparent electrode 14, 20 is designed as a planar electrode structure; a first voltage V1 is applied between the transparent electrodes 18 and 26, and a second voltage V2 is applied between the transparent electrodes 14 and 26 to form a circular symmetric voltage distribution.
By controlling the magnitude of the first voltage V1 and the second voltage V2, the mixture of the liquid crystal and the liquid crystalline polymer in the refractive index distribution film 1 can be adjusted to form a circular symmetric refractive index distribution. Wherein, the glass substrate 12, 20, 28 of this preferred embodiment can be substituted by a material with high dielectric constant or high impedance.
With reference to
With reference to
More specifically, components used for manufacturing a refractive index distribution film include a glass substrate 30, 32, a transparent electrode 34, 36, and an alignment layer 38, 40. Wherein, the components used for manufacturing the refractive index distribution film are disposed along the Z-direction include a transparent electrode 34, a glass substrate 30, an alignment layer 38, an alignment layer 40, a transparent electrode 36 and a glass substrate 32, and a mixture of a liquid crystal and a liquid crystalline polymer used for forming the refractive index distribution film 1 is disposed between the alignment layer 38 and the alignment layer 40. In the present embodiment, a voltage V3 is applied between the transparent electrode 34 and the transparent electrode 36, and the glass substrate 30 is designed thicker on a side and thinner on the other opposite side to achieve a non-uniform electric field distribution. In other words, the electric field at a position on the thicker side is smaller, and the electric field at a position on the thinner side is greater, so that a refractive index distribution film with a gradual refractive index distribution can be manufactured.
In addition to the aforementioned manufacturing method, another method of using a pixel electrode to drive a liquid crystal and a liquid crystalline polymer mixture at different positions in the refractive index distribution film 1 to manufacture a refractive index distribution film with a non-uniform refractive index distribution, such as the aforementioned refractive index distribution film with a gradual and symmetric refractive index distribution or the refractive index distribution film with any refractive index distribution.
With reference to
The first refractive index distribution film 120 composed of a liquid crystal and a liquid crystalline polymer having the feature of birefringence is manufactured by the aforementioned method and encapsulated inside a flexible substrate 100. The first refractive index distribution film 120 has a first refractive index in the X-direction and a second refractive index in the Y-direction.
The flexible substrate 100 is a laminating film or a flexible plastic substrate used for packaging the first refractive index distribution film 120. In the present embodiment, after the first refractive index distribution film is packaged inside the flexible substrate 100, and an adhesive 121 can be coated onto a side of the flexible substrate 100 and adhered with a first side 111 of the first lens 110, so that the focal length of the first lens 110 can be adjusted. In industrial applications, the flexible substrate 100 encapsulated with the first refractive index distribution film 120 can be laminated onto a glasses lens for adjusting the power of the glasses.
With reference to
In the present embodiment, the second refractive index distribution film 130 is encapsulated inside the flexible substrate 100, and the first refractive index distribution film 120 has an optical axis in the X-direction, and the second refractive index distribution film 130 has an optical axis in the Y-direction. Wherein, the flexible substrate 100 can be a laminating film or a flexible plastic film for encapsulating the first refractive index distribution film 120 and the second refractive index distribution film 130. With the two refractive index distribution films 120, 130 with their optical axes perpendicular to each other, the liquid crystalline polymer lens structure 3 of the present embodiment can achieve the expected effect without requiring the polarizer.
With reference to
It is noteworthy that each liquid crystalline polymer lens structure 2, 3, 4 of the first embodiment, the second embodiment and the third embodiment has the first refractive index and the second refractive index of the first refractive index distribution film 120 and the third refractive index and the fourth refractive index of the second refractive index distribution film 130 in the X- and Y-directions, and also has a circular symmetric optical power, a gradual optical power or any refractive index distribution. By adjusting the refractive index distribution of the refractive index distribution film in the X- and Y-directions, the focal length of the lens or the power of glasses can be adjusted.
With reference to
With reference to
With reference to
Wherein, the first alignment layer 280 is disposed on the first electrode layer 250, and the first liquid crystal layer 290 is disposed on the first alignment layer 280, and the first refractive index distribution film 120 is disposed on the first liquid crystal layer 290. Wherein, the first refractive index distribution film is the refractive index distribution film 120 manufactured by the aforementioned method and composed of a liquid crystal and a macromolecular polymer, and the first refractive index distribution film has the feature of birefringence.
With the first liquid crystal layer 290 in the composite layer 270 as shown in the figure, if a voltage V is applied between the first electrode layer 250 and the second electrode layer 260, the arrangement of the liquid crystals in the first liquid crystal layer will be affected and rotated, so that the polarization direction of the incident light can be changed, and the focal length of the liquid crystalline polymer lens structure 5 can be changed. If an additional polarizer 300 is added at a position opposite to the first side 211 of the first lens 200, the liquid crystalline polymer lens structure 5 can be used as a signal switch of the optical signal or applied in 3D display technologies.
With reference to
The second liquid crystal layer 310 is disposed on the second refractive index distribution film 130, and the second alignment layer 320 is disposed on the second liquid crystal layer 310. Wherein, the alignment direction of the first liquid crystal layer 290 is different from the alignment direction of the second liquid crystal layer 310, and the alignment direction of the first refractive index distribution film 120 is different from the alignment direction of the second refractive index distribution film 130. Since the liquid crystalline polymer distribution film has a dielectric constant distribution and an ability of aligning liquid crystals, therefore this present embodiment with the design of the liquid crystal and the electrode layer can achieve the effect of a dynamic lens. For example, if no voltage is applied between the electrode layers in the present embodiment, the liquid crystalline polymer lens structure 6 will have a constant optical power. On the other hand, if a voltage is applied between the electrode layers, the liquid crystalline polymer lens structure 6 will have a continuous optical power distribution.
It is noteworthy that by adjusting the alignment directions of the first alignment layer 280 and the second alignment layer 320, the first liquid crystal layer 290 or the second liquid crystal layer 310 of the present embodiment can be aligned as an anti-parallel alignment, a vertical alignment, a hybrid alignment or a twisted nematic alignment.
With reference to
The polarizer 400 is installed on a side of the refractive index distribution film 10, and the polarization controller 410 is installed between the polarizer 400 and the refractive index distribution film 10. Wherein, the polarization controller 410 is used for changing the polarization direction of a polarized light passing through the polarizer 400 in order to change the focal length of the liquid crystalline polymer lens structure 7. For example, if the polarization controller 410 changes the polarization direction of the polarized light passing through the polarizer 400 from the X-direction to the Y-direction or vice versa, the liquid crystalline polymer lens structure 7 will have two different optical power distributions.
In one embodiment, the refractive index distribution film may be utilized to compensate the aberration generated by an optical module. Referring to
Continuing the above description, in one embodiment, the optical module comprises a free form lens. As shown in
In another embodiment, the optical module of the optical system comprises a curved reflector. Referring to
In yet another embodiment, the optical module of the optical system comprises a lens and a beam splitter. Referring to
In yet another embodiment, the optical module of the optical system comprises a lens and a reflector. Referring to
In yet another embodiment, the optical module of the optical system comprises a curved mirror. As shown in
In one embodiment, the display system comprises an optical system and an image panel, in one embodiment, the display system comprises but not limited to a head-mount display. The optical system comprises an optical module and a refractive index distribution film, wherein the optical module comprises a curved surface, such as a lens or a curved reflector. The refractive index distribution film comprises a liquid crystal and a liquid crystalline polymer, wherein a refractive index distribution of the refractive index distribution film is asymmetric; the refractive index distribution film is arranged on a first side or a second side of the optical module; and the refractive index distribution film is utilized to compensate the aberration generated by the optical module. The image panel for displaying an image, wherein the image panel set on a light entrance side of the optical system, and the image light projected from the image panel passes through the optical system to a viewer's eyes. In one embodiment, the refractive index distribution film is attached on a first side (light entrance surface) or a second side (light exit surface) of the optical module.
Continuing the above description, in one embodiment, the lens comprises a free form lens. As shown in
In another embodiment, the optical module of the display system comprises a curved reflector. Referring to
In yet another embodiment, the optical module of the display system comprises a lens and a beam splitter. Referring to
In yet another embodiment, the optical module of the display system comprises a lens and a reflector. Referring to
In yet another embodiment, the optical module of the display system comprises a curved mirror. As shown in
In summation of the description above, the refractive index distribution film has a plurality of the refractive index distribution and the tilt angle of the liquid crystal of the refractive index distribution film is fixed and cannot be changed by an external electronic device. Due to no additional electrically-controlled component is needed to change the refractive index distribution, the production cost can be reduced substantially. Besides, the refractive index distribution film can be encapsulated by a flexible substrate and laminated onto a glasses lens for changing the power of glasses, providing additional optical power for a presbyopia's reading ability. Moreover, the refractive index distribution film can be adhered onto or attached on an optical module to compensate the aberration generated by the optical module which has an off-axis incident light or has a large incident angle. Therefore, the refractive index distribution film of the present invention can be applied onto various kinds of lenses or curved reflector easily or laminated onto an optical module to act as a simple and convenient lens sticker.
While the means of specific embodiments in present invention has been described by reference drawings, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims.
Claims
1. An optical system with an aberration compensation function, comprising:
- an optical module, comprising a curved surface; and
- a refractive index distribution film comprising a liquid crystal and a liquid crystalline polymer, wherein a refractive index distribution of the refractive index distribution film is asymmetric and the tilt angle of the liquid crystal of the refractive index distribution film is fixed; the refractive index distribution film is arranged on a first side or a second side of the optical module; and the refractive index distribution film is utilized to compensate the aberration generated by the optical module.
2. The optical system according to claim 1, wherein the optical module comprises a lens or a curved reflector.
3. The optical system according to claim 1, wherein the optical module comprises a free form lens.
4. The optical system according to claim 1, wherein the optical module comprises a free form lens and a see-through corrector; the first side is a light entrance surface of the free form lens; the second side is a light exit surface of the free form lens; the see-through corrector is attached on a third side of the free form lens; and an incident light passes through the free form lens from the first side, and the incident light is reflected by the second side and the third side to pass through the second side of the free form lens.
5. The optical system according to claim 1, wherein the optical module comprises a lens and a beam splitter; the lens is set on a light entrance side of the beam splitter; and the first side is a light entrance surface or a light exit surface of the lens; and the second side is a light entrance surface or a light exit surface of the beam splitter.
6. The optical system according to claim 1, wherein the optical module comprises a lens and a reflector; the lens is set on a light entrance side of the reflector; the first side is a light entrance surface or a light exit surface of the lens; the second side is a light entrance surface or a light exit surface of the reflector.
7. The optical system according to claim 1, wherein the optical module comprises a curved reflector array; and the refractive index distribution film is set on a light entrance side or a light exit side of the curved reflector array.
8. The optical system according to claim 1, wherein the refractive index distribution film is flexible.
9. The optical system according to claim 1, wherein the refractive index distribution film is directly adhered on the first side or the second side of the optical module.
10. A display system with an aberration compensation function, comprising:
- an optical system, comprising: an optical module, comprising a curved surface; and a refractive index distribution film comprising a liquid crystal and a liquid crystalline polymer, wherein a refractive index distribution of the refractive index distribution film is asymmetric and the tilt angle of the liquid crystal of the refractive index distribution film is fixed; the refractive index distribution film is arranged on a first side or a second side of the optical module; and the refractive index distribution film is utilized to compensate the aberration generated by the optical module;
- an image panel for displaying an image, wherein the image panel set on a light entrance side of the optical system, and the image light projected from the image panel passes through the optical system to a viewer's eyes.
11. The display system according to claim 10, wherein the optical module comprises a lens or a curved reflector.
12. The display system according to claim 10, wherein the optical module comprises a free form lens.
13. The display system according to claim 10, wherein the optical module comprises a free form lens and a see-through corrector; the first side is a light entrance surface of the free form lens; the second side is a light exit surface of the free form lens; the see-through corrector is attached on a third side of the free form lens; and the image light projected from the image panel passes through the free form lens from the first side, and the image light is reflected by the second side and the third side to pass through the second side of the free form lens into the viewer's eyes.
14. The display system according to claim 10, wherein the optical module comprises a lens and a beam splitter; the lens is set on a light entrance side of the beam splitter; the first side is a light entrance surface or a light exit surface of the lens; and the second side is a light entrance surface or a light exit surface of the beam splitter; and the image light projected from the image panel passes through the refractive index distribution film, the lens, and the beam splitter to reflect into the viewer's eyes.
15. The display system according to claim 10, wherein the optical module comprises a lens and a reflector; the lens is set on a light entrance side of the reflector; and the first side is a light entrance surface or a light exit surface of the lens; the second side is a light entrance surface or a light exit surface of the reflector; and the image light projected from the image panel passes through the refractive index distribution film, the lens, and the reflector to reflect into the viewer's eyes.
16. The display system according to claim 10, wherein the optical module comprises a curved reflector array; and the refractive index distribution film is attached on the first side or the second side of the lens; and the image light projected from the image panel passes through the refractive index distribution film, the curved reflector array to reflect into the viewer's eyes.
17. The display system according to claim 10, wherein the refractive index distribution film is flexible.
18. The display system according to claim 10, wherein the refractive index distribution film is directly adhered on the first side or the second side of the optical module.
Type: Application
Filed: Apr 17, 2015
Publication Date: Aug 6, 2015
Inventors: Hung-Shan CHEN (Taichung City), Yi-Hsin LIN (Zhubei City)
Application Number: 14/689,919