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CN-115087918-B - Liquid crystal device

CN115087918BCN 115087918 BCN115087918 BCN 115087918BCN-115087918-B

Abstract

The invention relates to a liquid crystal device comprising at least two opposing transparent substrates, at least one liquid crystal switching layer sandwiched between said opposing substrates, the liquid crystal switching layer comprising one or more polymerized photoreactive mesogens of formula I ,R 11 -Sp 11 -X 11 [-A-Z] o -A 11 -CY 11 ＝CY 12 [-C＝O] x [-O] y -A[-Z-A] p -X 21 -Sp 21 -R 21 I wherein R 11 、R 21 、A 11 、A、Z、X 11 、X 21 、Y 11 、Y 12 、Sp 11 、Sp 21 、o、p、x and y have one of the meanings given herein, and one or more nematic compounds, electrode structures provided on one or both of the opposing substrates, wherein one or more of said substrates is additionally provided with a grating or lens structure adjacent to the LC switching layer. The invention further relates to a method of producing said liquid crystal device, to the use of said liquid crystal device in various types of optical and electro-optical devices, and to electro-optical devices comprising said liquid crystal device.

Inventors

  • SNOW BENJAMIN
  • S. Shimianowski
  • Qi Tengquan
  • K. SCHNEIDER

Assignees

  • 默克专利股份有限公司

Dates

Publication Date
20260505
Application Date
20210210
Priority Date
20200213

Claims (13)

  1. An LC device, which is an LC beam steering device, comprising At least two opposing transparent substrates, the transparent substrates, At least one LC switching layer sandwiched between said opposing substrates, said LC switching layer comprising a polymer obtainable from one or more photoreactive mesogens of formula I, Wherein the method comprises the steps of A 11 represents a group selected from the group consisting of: a) A group consisting of 1, 4-phenylene and 1, 3-phenylene, wherein, in addition, one or two CH groups are optionally replaced by N, and wherein in the groups of a), one or more H atoms are optionally replaced by L, B) A group selected from the group consisting of: Wherein in the radicals of b) one or more H atoms are optionally replaced by L and/or one or more double bonds are optionally replaced by single bonds and/or one or more CH groups are optionally replaced by N, Each of a, independently of the other, has one of the meanings of a 11 at each occurrence or represents a meaning selected from: a) A group consisting of trans-1, 4-cyclohexylene, 1, 4-cyclohexenylene, in which one or more non-adjacent CH 2 groups are optionally replaced by-O-and/or-S-and in which one or more H atoms are optionally replaced by F, or B) The group consisting of tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, tetrahydrofuran-2, 5-diyl, cyclobutane-1, 3-diyl, piperidine-1, 4-diyl, thiophene-2, 5-diyl and selenophene-2, 5-diyl, which may in each case also be monosubstituted or polysubstituted by L, L represents identically or differently on each occurrence -OH、-F、-Cl、-Br、-I、-CN、-NO 2 、SF 5 、-NCO、-NCS、-OCN、-SCN、-C(=O)N(R z ) 2 、-C(=O)R z 、-N(R z ) 2 、 an optionally substituted silyl group, an optionally substituted aryl group having 6 to 20C atoms or a linear or branched or cyclic alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 25C atoms, or X 21 -Sp 21 -R 21 , M represents-O-, -S-, -CH 2 -、-CHR z -or-CR y R z -, R y and R z each independently of one another represent H, CN, F or alkyl having 1 to 12C atoms, wherein one or more H atoms are optionally replaced by F, Y 11 and Y 12 each independently of one another represent H, F, phenyl or optionally fluorinated alkyl having 1 to 12C atoms, Z in each occurrence independently of one another represents a single bond 、-COO-、-OCO-、-O-CO-O-、-OCH 2 -、-CH 2 O-、-OCF 2 -、-CF 2 O-、-(CH 2 ) n -、-CF 2 CF 2 -、 -CH=CH-、-CF=CF-、-CH=CH-COO-、-OCO-CH=CH-、-CO-S-、-S-CO-、-CS-S-、-S-CS-、-S-CSS- or-C.ident.C-, N represents an integer between 2 and 8, O and p each independently represent 0,1 or 2, X and y each independently represent 0 or 1, however if x represents 0, y cannot represent 1, X 11 and X 21 independently of one another represent a single bond 、-CO-O-、-O-CO-、-O-COO-、-O-、-CH=CH-、 -C≡C-、-CF 2 -O-、-O-CF 2 -、-CF 2 -CF 2 -、-CH 2 -O-、-O-CH 2 -、-CO-S-、-S-CO-、-CS-S-、-S-CS-、-S-CSS- or-S-, Sp 11 and Sp 21 each and independently represent a single bond or a spacer group containing 1 to 20C atoms, wherein one or more non-adjacent and non-terminal CH 2 groups are optionally replaced by -O-、-S-、-NH-、-N(CH 3 )-、-CO-、-O-CO-、-S-CO-、-O-COO-、-CO-S-、 -CO-O-、-CF 2 -、-CF 2 O-、-OCF 2 -、-CH(OH)-、-CH( alkyl) -, -CH (alkenyl) -, -CH (alkoxy) -, -CH (oxaalkyl) -, -CH=CH-, or-C≡C-, but alternatively such that no two O atoms are adjacent to each other and no two groups selected from-O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-and-ch=ch-are adjacent to each other, R 11 is represented by the formula P, R 21 represents P, halogen, CN, optionally fluorinated alkyl or alkenyl having up to 15C atoms, wherein one or more non-adjacent CH 2 groups are optionally replaced by-O-, -S-, -CO-, -C (O) O-, -O-C (O) -, O-C (O) -O-substitution, P in each occurrence is independently of each other a polymerizable group, And one or more nematic compounds, which are selected from the group consisting of, Electrode structures provided on one or both of the opposing substrates, Characterized in that one or more of the substrates corresponds to a grating or lens structure or the substrate is additionally provided with a grating or lens structure adjacent to the LC switching layer, the one or more substrates corresponds to or is provided with a plano-concave lens structure, or a plano-convex lens structure, or a biconcave lens structure, or a refractive fresnel lens structure, or a diffractive fresnel lens structure, the one or more substrates corresponds to or is provided with a surface relief grating, or a blazed grating, or a volume grating, or a Pancharatnam-Berry grating, or a bragg polarization grating, the maximum thickness of the LC switching layer being in the range of 10 μm to 100 μm.
  2. 2. The device of claim 1, wherein the maximum thickness of the LC switching layer is in the range of 10 μιη to 75 μιη.
  3. 3. A device according to claim 1 or 2, characterized in that the electrode structure used is selected from the group consisting of interdigitated electrodes, IPS electrodes, FFS electrodes or comb electrodes.
  4. 4. The device of claim 1 or 2, wherein the one or more nematic compounds are selected from the following formulas: Wherein the method comprises the steps of A represents a group consisting of 1 and 2, B represents 0 or 1, and the number of the groups is, R 1 and R 2 each independently of one another represent alkyl having 1 to 12C atoms, wherein another one or more non-adjacent CH 2 groups are optionally represented by-O-, -ch=ch-, -CO-, -O-CO-or-CO-O-substitution, Z x represents -CH=CH-、-CH 2 O-、-OCH 2 -、-CF 2 O-、-OCF 2 -、-O-、-CH 2 -、-CH 2 CH 2 - or a single bond, Z y represents -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -、-CF=CF-、-CH=CH-CH 2 O- or a single bond, L 1-4 each independently of the other represents F, cl, OCF 3 、CF 3 、CH 3 、CH 2 F、CHF 2 .
  5. 5. The device of claim 1 or 2, wherein the one or more nematic compounds are selected from the following formulas: Wherein the method comprises the steps of R 20 each identical or different represents a halogenated or unsubstituted alkyl or alkoxy radical having 1 to 15C atoms, wherein in addition one or more of these groups CH 2 groups are each, independently of one another, optionally substituted by-C.ident.C-, in such a way that the O atoms are not directly connected to one another-CF 2 O-, -ch=ch-, -O-, -CO-O-or-O-CO-substitution, X 20 each identically or differently represents F, cl, CN, SF 5 , SCN, NCS, alkyl halide, alkenyl halide, alkoxy halide or alkenyloxy halide, each having up to 6C atoms, and Y 20-24 each independently represents H or F, identically or differently; W represents H or a methyl group, and the R represents a methyl group, 。
  6. 6. A device according to claim 1 or 2, wherein the one or more nematic compounds are selected from the following formulae: Wherein R 20 、X 20 , W and Y 20-23 have the meanings indicated in formula III in claim 5, and And is also provided with 。
  7. 7. The device of claim 1 or 2, wherein the one or more nematic compounds are selected from the following formulas: Wherein the individual radicals have the following meanings: R 3 and R 4 each independently of one another represent alkyl having 1 to 12C atoms, wherein the other or two non-adjacent CH 2 groups are optionally represented by-O-, optionally in such a way that the O atoms are not directly linked to each other-ch=ch-, -CO-, -O-CO-or-CO-O-substitution, Z y represents -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -、-CF=CF-、-CH=CH-CH 2 O- or a single bond.
  8. 8. A device according to claim 1 or 2, characterized in that it is a beam focusing device.
  9. 9. A method of manufacturing a device according to any one of claims 1 to 8, comprising one or more of the following steps: providing electrode structures on one or more substrates, providing grating or lens structures on one or more substrates, assembling the liquid crystal cell, Filling the liquid crystal cell with an LC medium comprising one or more photoreactive mesogens of formula I and one or more nematic compounds, Illuminating the liquid crystal cell with linearly polarized light, -Curing the polymerizable compound of the LC medium by irradiation with ultraviolet light or visible light having a wavelength of 450 nm or less.
  10. 10. Use of a device according to any of claims 1 to 8 in an electro-optical device.
  11. 11. An electro-optical device comprising a device according to any one of claims 1 to 8.
  12. 12. An electro-optic device as claimed in claim 11, wherein the electro-optic device is selected from devices for augmented reality or virtual reality applications.
  13. 13. An electro-optic device as claimed in claim 11 or 12, which is a goggle or a contact lens.

Description

Liquid crystal device Technical Field The invention relates to a liquid crystal device comprising at least two opposing transparent substrates, at least one liquid crystal switching layer sandwiched between the opposing substrates, the liquid crystal switching layer comprising one or more polymerized photoreactive mesogens of formula I, R11-Sp11-X11[-A-Z]o-A11-CY11＝CY12[-C＝O]x[-O]y-A[-Z-A]p-X21-Sp21-R21 I Wherein R11、R21、A11、A、Z、X11、X21、Y11、Y12、Sp11、Sp21、o、p、x and y have one of the meanings given in the present invention, and one or more nematic compounds, provided on one or both of the opposing substrates, characterized in that one or more of the substrates corresponds to a grating or lens structure or the substrate is additionally provided with a grating or lens structure adjacent to the LC switching layer. The invention further relates to a method of manufacturing said liquid crystal device, to the use of said liquid crystal device in various types of optical and electro-optical devices, and to electro-optical devices comprising said liquid crystal device. Background and prior art Accurate positioning of the laser beam or light is critical for practical applications such as light detection and ranging (LiDAR), displays, microscopes, optical tweezers, and laser micromachining, for example. For example, as the most critical application to facilitate beam steering technology, liDAR may map landscapes in three-dimensional (3D) space and serve as space station navigation, telescope docking, and energizing technologies for autonomous cars, unmanned aerial vehicles, and underwater vehicles. So far, too many beam steering methods have been demonstrated. In general, they can be divided into two groups, mechanical and non-mechanical beam steering. Mechanical methods include scanning/rotating mirrors, rotating prisms, piezoelectric actuators, and microelectromechanical system (MEMS) mirrors. On the other hand, non-mechanical options include acousto-optic and electro-optic deflectors, electrowetting, and Liquid Crystal (LC) technology, to name a few. Although conventional mechanical beam steering devices are fairly robust, some technical problems remain to be overcome, such as relatively short service life, heavy weight, high power consumption, and high cost. In contrast, recently developed mechanical and non-mechanical beam diverters are expected to address these drawbacks. As a powerful candidate, LC-based beam diverters can be lightweight, compact, low power consumption, and inexpensive. LC is a self-assembled soft material, consisting of certain anisotropic molecules with an orientation order. They can respond to various external stimuli, including heat, electric and magnetic fields, and light. For example, in the presence of an electric field, the LC director may reorient due to both optical and dielectric anisotropy of the LC molecules, resulting in refractive index modulation (birefringence). Using this simple principle, an LC Spatial Light Modulator (SLM), also known as an LC Optical Phased Array (OPA), can be built by pixelating such refractive index modulators in a two-dimensional (2D) array. LC-based OPAs have been developed as early as thirty years ago, but they continue to evolve. Meanwhile, other LC-based beam diverters, such as composite prisms, resistive electrodes, LC cladding waveguides, panchatam-Berry phase deflectors, and LC volume gratings, have also emerged, exhibiting tremendous new application potential. Liquid crystal based beam steering or beam focusing devices are described, for example, in US 2002/003601A1, US 2007/0182915 A1 or US 2019/0318706 A1. In detail, US 2002/003601 A1 discloses a beam steering system using electrical operation, comprising a grating and a liquid crystal material. US 2007/0182915 A1 discloses a liquid crystal diffractive lens element and an optical head device, which can switch focal lengths of both outgoing light and return light by a single element. US 2019/0318706 A1 discloses a display device comprising an electronic display having an array of pixels configured to display a sequence of subframes, and an image shifting electro-optic device operable to shift at least a portion of an image of the array of display pixels in synchronism with the display of the sequence of subframes to form a sequence of offset subframes images for providing enhanced image resolution, pixel correction in a composite image. The image-shifting electro-optic device may include a polarization switch in series with the polarization grating for shifting image pixels between offset image positions in conjunction with displaying successive subframes. Either the beam steering or beam focusing devices described above require an alignment layer (e.g., polyimide) to first align the liquid crystal in the desired orientation. The effort to produce polyimide layers, process the layers, and improve with bumps or polymer layers is relatively large. Therefore, a simplified technique is desired which