Patents by Inventor David M. Walba
David M. Walba has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9187500Abstract: A novel approach for generating FLC electro-optics with gray-scale resolution includes using FLC material that is: (i.) capable of electrostatic V-shape switching, (ii.) capable of optical latching, and (iii.) not requiring DC balance.Type: GrantFiled: July 13, 2012Date of Patent: November 17, 2015Assignee: The Regents of the University of Colorado, a body corporateInventor: David M Walba
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Patent number: 8963140Abstract: The present disclosure is for improved organic semiconductors and improved organic photovoltaics. Liquid crystalline bent-core molecules in the B4 subphase of the present disclosure may be incorporated into improved organic semiconductors. Liquid crystalline bent-core molecules in the B4 subphase of the present disclosure may be incorporated into improved organic photovoltaics that may have improved quantum efficiencies over pre-existing organic photovoltaics.Type: GrantFiled: February 11, 2013Date of Patent: February 24, 2015Assignee: The Regents of the University of ColoradoInventor: David M. Walba
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Publication number: 20130016295Abstract: A novel approach for generating FLC electro-optics with gray-scale resolution includes using FLC material that is: (i.) capable of electrostatic V-shape switching, (ii.) capable of optical latching, and (iii.) not requiring DC balance.Type: ApplicationFiled: July 13, 2012Publication date: January 17, 2013Inventor: David M. Walba
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Patent number: 7682521Abstract: The present disclosure includes a method that allows one to obtain high quality alignment of nematic or smectic liquid crystal (LC) polymer glasses in thin films. The present disclosure also includes thin films of aligned smectic or nematic LC main-chain polymer glasses, including aligned chiral smectic C* ferroelectric LC main-chain polymer glasses. The disclosure also includes electro-optical devices, including electro-optical devices comprising aligned chiral smectic C* ferroelectric LC main-chain polymer glasses.Type: GrantFiled: August 23, 2004Date of Patent: March 23, 2010Assignee: The Regents of the University of ColoradoInventor: David M. Walba
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Patent number: 7374948Abstract: The disclosure provides methods for the determination of the enantiomeric excess of chiral compounds. The methods involve doping a chiral analyte into an achiral liquid crystal host to form a chiral dopant/host liquid crystal mixture. An electro-optic signature of the mixture is then determined and is used to calculate the enantiomeric excess of the chiral analyte. The disclosure also provides systems for performing the disclosed methods of determining enantiomeric excess.Type: GrantFiled: May 31, 2005Date of Patent: May 20, 2008Assignee: The Regents of the University of ColoradoInventors: David M Walba, Noel A. Clark
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Patent number: 6870163Abstract: Bistable and analog FLC devices employing chiral nonracemic liquid crystal materials exhibiting de Vries smectic A phases. The invention provides certain liquid crystal material that can be employed in both bistable and analog device configurations. The invention also provides a method for identifying liquid crystal materials that will exhibit both bookshelf structure in SSFLC cells and provide V-shaped switching in an analog device configuration.Type: GrantFiled: September 1, 2000Date of Patent: March 22, 2005Assignee: Displaytech, Inc.Inventors: Jiuzhi Xue, David M. Walba
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Patent number: 6569504Abstract: This invention provides LC compositions useful as birefringent materials in electrooptic devices which exhibit zero or low negatively sloped birefringence dispersioon (e.g., exhibiting positive birefringence dispersion significantly lower than that of currently available LC compositions) or more preferably positively sloped birefringence dispersion in which birefringence of the material increases with wavelength. The invention provides compounds useful as components of LC compositions which exhibit negative birefringence where n0 is higher than ne. The compounds of this invention are dimers of LC-like compounds in which the monomers are linked to each other through a high birefringence moiety (dimerization linker). The LC monomers consist of an LC core and one or two tail groups. Preferred monomers for this invention have low birefringence in comparison to the birefringence of the monomer linking moiety.Type: GrantFiled: August 11, 2000Date of Patent: May 27, 2003Assignee: Displaytech, Inc.Inventors: David M. Walba, Daniel J. Dyer, Uwe Muller, Peter Cobben, Xin Hua Chen, William Thurmes, Michael Wand
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Patent number: 6139771Abstract: This invention provides LC compositions useful as birefringent materials in electrooptic devices which exhibit zero or low negatively sloped birefringence dispersion (e.g., exhibiting positive birefringence dispersion significantly lower than that of currently available LC compositions) or more preferably positively sloped birefringence dispersion in which birefringence of the material increases with wavelength. The invention provides compounds useful as components of LC compositions which exhibit negative birefringence where n.sub.o is higher than n.sub.e. The compounds of this invention are dimers of LC-like compounds in which the monomers are linked to each other through a high birefringence moiety (dimerization linker). The LC monomers consist of an LC core and one or two tail groups. Preferred monomers for this invention have low birefringence in comparison to the birefrigence of the monomer linking moiety.Type: GrantFiled: April 4, 1997Date of Patent: October 31, 2000Assignee: Displaytech, Inc.Inventors: David M. Walba, Daniel J. Dyer, Uwe Muller, Peter Cobben, Xin Hua Chen, William Thurmes, Michael Wand
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Patent number: 5866036Abstract: Chiral nonracemic molecules which are useful as high tilt, high polarization and/or high birefringence FLC materials or are useful as components of such FLC materials and which have the following general structure are provided:RO--(Ph.sub.1).sub.m --(A).sub.a --(Ph.sub.2).sub.n --(B).sub.b --(Ph.sub.3).sub.p --Twhere Ph.sub.1, Ph.sub.2 and Ph.sub.Type: GrantFiled: February 2, 1994Date of Patent: February 2, 1999Assignee: Displaytech, Inc.Inventors: Michael D. Wand, Rohini T. Vohra, David M. Walba, Sean D. Monahan
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Patent number: 5658493Abstract: This invention provides chiral, non-racemic compounds and liquid crystal compositions comprising such compounds. The compounds of this invention include those having the formula: ##STR1## wherein k=0 or 1 and when k=1, B=COO, OOC, --C.tbd.C--, or --C.tbd.C--C.tbd.C--; X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are either H, an electron donor or an electron acceptor where at least one of the groups X.sub.1, X.sub.2, X.sub.3 or X.sub.4 is an electron acceptor and at least one of these groups is an electron donor or H and when one of X.sub.1 or X.sub.3 is an electron donor or H, the other is an electron acceptor and when one of X.sub.2 or X.sub.4 is an electron donor or H, the other is an electron acceptor; and R.sub.1 and R.sub.2 can be various substituted and unsubstituted alkanes and monoalkenes. Compounds provided include those where one of R.sub.1 or R.sub.2 is a chiral non-racemic tail group, particularly a group selected from --O--C*H(CH.sub.3)R.sub.c, --O--C*H(CH.sub.3)COOR.sub.d, and --O--CH.sub.Type: GrantFiled: May 26, 1995Date of Patent: August 19, 1997Assignee: University Research CorporationInventors: David M. Walba, Maria Blanca Ros, James A. Rego, Teresa Sierra
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Patent number: 5637256Abstract: This invention provides chiral nonracemic compound of formula: ##STR1## wherein n and m are 0 or 1, but one of n or m must be 1; k=0 or 1; B=COO or OOC; X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are either H, an electron donor or an electron acceptor where at least one of the groups X.sub.1, X.sub.2, X.sub.3 or X.sub.4 is an electron acceptor and at least one of these groups is an electron donor and when one of X.sub.1 or X.sub.3 is an electron donor, the other is an electro a acceptor and when one of X.sub.2 or X.sub.4 is an electron donor, the other is an electron acceptor; and R.sub.1 and R.sub.2 can be various substituted and unsubstituted alkanes and monoalkenes. Compounds provided include those where one of R.sub.1 or R.sub.2 is a chiral non-racemic tail group, particularly a group selected from --O--C.sup.* H(CH.sub.3)R.sub.c, --O--C.sup.* H(CH.sub.3)COOR.sub.d, and --O--CH.sub.2 C.sup.* HF--C.sup.* HF--R.sub.2 in which the .sup.* indicates an asymmetric carbon enriched in one stereoconfiguration where R.Type: GrantFiled: May 26, 1995Date of Patent: June 10, 1997Assignee: University Research CorporationInventors: David M. Walba, Maria B. Ros, James A. Rego, Teresa Sierra
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Patent number: 5596434Abstract: A method of aligning liquid crystals in the construction of liquid crystal cell for use in optical devices is provided. The method involves formation of a self-assembled monolayer on substrates used to form the cells. The substrate having the monolayer are then rubbed in one direction. Two substrates are combined with rubbing directions anti-parallel and spaced to form a cell. A liquid crystal is then inserted and aligned between the substrates. High quality alignment is achieved with this method.Type: GrantFiled: September 24, 1993Date of Patent: January 21, 1997Assignee: University Research CorporationInventors: David M. Walba, Charles A. Liberko
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Patent number: 5543078Abstract: The present invention provides ferroelectric liquid crystal and liquid crystal compounds, among which are compounds which possess large X.sup.(2), i.e. second order nonlinear susceptibility and thus make them useful in optical and nonlinear optical applications. The invention includes chiral nonracemic compounds of formula ##STR1## where one of n or m is 1; k is 1 and B is COO or OOC; R' is a straight-chain or branched alkyl or monoalkene group having from 1 to 20 carbon atoms where one or more of the non-neighboring carbon atoms in R', except any unsaturated carbon atoms, can be replaced with O, S or a Si(CH.sub.3).sub.2 group; and R' is a chiral nonracemic tail group selected from the group consisting of --O--C*H(CH.sub.3)R.sub.c, --O--C*H(CH.sub.3)COOR.sub.d and --O--CH.sub.2 C*HF--C*HF--R.sub.6 in which the * indicates an asymmetric carbon enriched in one stereoconfiguration which for --O--CH.sub.2 C*HF--C*HF--R.sub.e is either the (S,S) or (R,R) stereoconfiguration wherein: R.sub.Type: GrantFiled: November 19, 1993Date of Patent: August 6, 1996Assignee: University Research CorporationInventors: David M. Walba, Maria B. Ros, James A. Rego, Teresa Sierra
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Patent number: 5380460Abstract: Chiral, nonracemic compounds of the general formula: ##STR1## wherein m and n are either both zero, both equal one or n is equal to one and m is equal to zero, X and Y and Z are halogens, R' is an alkyl, alkoxyl, alkenyl, thioalkyl, thioether, ether, or alkylsilyl group containing three to fifteen carbon atoms, and R is an alkyl group having one to fifteen carbon atoms and where Ar is:--A.sub.a --(E).sub.e --B.sub.b --(F).sub.f --D.sub.d --where A, B and D independently of one another are aromatic rings which are selected from the group consisting of a phenyl, a pyridine ring, a pyrimidine ring, a pyridizine ring, a pyrazine ring and a thiadiazole ring, wherein a, b and d are integers from 0-3 such that a+b+d=2-3, where E and F independently of one another are linking groups selected from the group consisting of a --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --O--, --CH.sub.2 --S--, --O--CH.sub.2 --, --S--CH.sub.Type: GrantFiled: September 20, 1991Date of Patent: January 10, 1995Assignee: Displaytech, Inc.Inventors: Michael D. Wand, William N. Thurmes, David M. Walba
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Patent number: 5178793Abstract: Chiral, nonracemic compounds of the general formula: ##STR1## in which the chiral tail group containing three asymmetric carbons (as indicated by *) is incorporated into a suitable FLC core moiety R--Ar.sub.2 are provided. The Ar.sub.2 core can include phenylbenzoate, biphenyl, phenylpyridine or phenylpyrimidine. R is an alkyl or alkoxy group having three to fifteen carbon atoms and R' is an alkyl group having from three to twelve carbon atoms. The compounds are useful as ferroelectric liquid crystal components having high polarization density. Compounds in which the chiral epoxide tail is the 1R-methyl-2S,3S-epoxy or 1S-methyl-2R,3R-epoxy enantiomer having higher polarization density.Type: GrantFiled: June 1, 1989Date of Patent: January 12, 1993Assignee: University Research CorporationInventors: Rohini T. Vohra, David M. Walba, Michael D. Wand
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Patent number: 5168381Abstract: Fast switching, high-contrast light valves and light valves which function for multi-level, gray-scale production are provided. Light valves of this invention employ two or more low-tilt, chiral smectic liquid crystal cells which are half-wave plates. Bistable FLC cells or FLC cells having smectic A* materials which display a field dependent tilt angle can be used. The FLC cells of exemplary device configurations are positioned sequentially along a light path through the device with the optic axes of the sequential FLC cells rotating in opposite directions upon application of a driving electric field thereacross. Light valves employing smectic C* and smectic A* liquid crystal cells are provided.Type: GrantFiled: December 27, 1990Date of Patent: December 1, 1992Assignee: University Research CorporationInventor: David M. Walba
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Patent number: 5145601Abstract: Liquid crystal and ferroelectric liquid crystal compounds having core moieties based on nicotinic acid and having the general formula: ##STR1## where A is N or N--O and where R.sub.1 and R.sub.2, independently of one another, are straight chain or branched alkyl groups having from 1 to 20 carbons are provided. Ferroelectric liquid crystals of the present invention include those compounds in which one of R.sub.1 or R.sub.2 are chiral nonracemic groups. The pyridines and pyridine n-oxides or the present invention are useful as components of liquid crystal materials and certain of these compounds are useful as components of ferroelectric liquid crystal materials.Type: GrantFiled: June 25, 1990Date of Patent: September 8, 1992Assignee: The University of Colorado Foundation Inc.Inventors: Bengt Otterholm, David M. Walba
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Patent number: 5138010Abstract: New ferroelectric liquid crystal (FLC) materials comprising linear and cyclic polysiloxanes are described. The FLCs exhibit high polarization and fast switching speeds. The disclosed polysiloxanes are derivitized with mesogenic groups which induce high polarization, specifically chiral nonracemic epoxide mesogens, having phenylbenzoate, reverse phenylbenzoate and biphenyl cores. These epoxy polysiloxanes are chemically stable over extended periods. Further, the epoxides can be crosslinked to produce FLC elastomers and like materials having optoelectronic applications. It was found that in the pure polysiloxanes, the smectic layers align along the rubbing direction of an anisotropic surface on contact with that surface.Type: GrantFiled: June 25, 1990Date of Patent: August 11, 1992Assignee: University of Colorado Foundation, Inc.Inventors: Patrick J. Keller, David M. Walba
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Patent number: 5061814Abstract: Chiral nonracemic molecules which are useful in the preparation of high polarization density FLC compositions and which have the following structure are provided: ##STR1## wherein Ph is a 1,4 substituted phenyl group, m=2 and n=1 or m=1 and n=2, asymmetric carbons are indicated by *. R is an alkyl group having three to fifteen carbon atoms, and R' is an alkyl group having one to seven carbons. The invention in particular provides compounds having the R,R or S,S configuration in the epoxide tail. The epoxy phenylbenzoates of this invention display a property of inducing a tilt angle greater than expected in FLC compositions in which they are combined.Type: GrantFiled: June 1, 1989Date of Patent: October 29, 1991Assignee: Displaytech, Inc.Inventors: Michael D. Wand, Rohini T. Vohra, David M. Walba
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Patent number: 5051506Abstract: Chiral, nonracemic compounds of the general formula: ##STR1## wherein m and n are either both zero, both equal one or n is equal to one and m is equal to zero, X and Y and Z are halogens, R' is an alkyl or alkoxy group having three to fifteen carbons, R is an alkyl group having one to fifteen carbons, and Ar is a 4,4'-substituted phenylvenzoate, 4,4'-substituted biphenylbenzoate, 5,4-substituted 2-phenylpyrimidine or 4,4'-substituted biphenyl core, and wherein * indicates a chiral center, which are useful as ferroelectric liquid crystal components having high polarization are described.Type: GrantFiled: March 4, 1988Date of Patent: September 24, 1991Assignee: Displaytech, Inc.Inventors: Michael D. Wand, David M. Walba