Patents by Inventor Janez Pirs
Janez Pirs 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: 8542334Abstract: A new concept of the LCD light-switching optical filter allowing for very high, electrically controlled, continuously variable light attenuation (up to ?100,000) optimized/symmetrized for the light incidence along the normal to the LCD plane is proposed. The new LCD light-switching optical filter also exhibits very low light attenuation dependence for the oblique incidence of light within a limited cone of angles off the normal incidence direction in compliance with the international safety and quality regulation EN 379 for personal protection equipment. According to the invention the problem is solved by specific, novel modification of the general principle of highly twisted nematic LCDs, allowing for the adaptation of the light transmission/driving voltage characteristics to specific requirements of the driving electronics as well as “symmetrizing” the overall optical birefringent properties, which in turn results in a high degree of their angular compensation.Type: GrantFiled: August 12, 2011Date of Patent: September 24, 2013Assignee: Institut Jozef StefanInventors: Janez Pirs, Matej Bazec, Silvija Pirs, Bojan Marin, Bernarda Urankar, Dusan Ponikvar
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Publication number: 20120002121Abstract: A new concept of the LCD light-switching optical filter allowing for very high, electrically controlled, continuously variable light attenuation (up to ?100,000) optimized/symmetrized for the light incidence along the normal to the LCD plane is proposed. The new LCD light-switching optical filter also exhibits very low light attenuation dependence for the oblique incidence of light within a limited cone of angles off the normal incidence direction in compliance with the international safety and quality regulation EN 379 for personal protection equipment. According to the invention the problem is solved by specific, novel modification of the general principle of highly twisted nematic LCDs, allowing for the adaptation of the light transmission/driving voltage characteristics to specific requirements of the driving electronics as well as “symmetrizing” the overall optical birefringent properties, which in turn results in a high degree of their angular compensation.Type: ApplicationFiled: August 12, 2011Publication date: January 5, 2012Inventors: Janez PIRS, Matej Bazec, Silvija Pirs, Bojan Marin, Bernarda Urankar, Dusan Ponikvar
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Patent number: 8026998Abstract: A new concept of the LCD light-switching optical filter allowing for very high, electrically controlled, continuously variable light attenuation (up to ?100.000) optimized/symmetrized for the light incidence along the normal to the LCD plane is proposed. The new LCD light-switching optical filter also exhibits very low light attenuation dependence for the oblique incidence of light within a limited cone of angles off the normal incidence direction in compliance with the international safety and quality regulation EN 379 for personal protection equipment. According to the invention the problem is solved by specific, novel modification of the general principle of highly twisted nematic LCDs, allowing for the adaptation of the light transmission/driving voltage characteristics to specific requirements of the driving electronics as well as “symmetrizing” the overall optical birefringent properties, which in turn results in a high degree of their angular compensation.Type: GrantFiled: May 9, 2006Date of Patent: September 27, 2011Assignee: Institut Josef StefanInventors: Janez Pirs, Silvija Pirs, Bojan Marin, Andrej Vrecko
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Publication number: 20090066882Abstract: A new concept of the LCD light-switching optical filter allowing for very high, electrically controlled, continuously variable light attenuation (up to ?100,000) optimized/symmetrized for the light incidence along the normal to the LCD plane is proposed. The new LCD light-switching optical filter also exhibits very low light attenuation dependence for the oblique incidence of light within a limited cone of angles off the normal incidence direction in compliance with the international safety and quality regulation EN 379 for personal protection equipment. According to the invention the problem is solved by specific, novel modification of the general principle of highly twisted nematic LCDs, allowing for the adaptation of the light transmission/driving voltage characteristics to specific requirements of the driving electronics as well as “symmetrizing” the overall optical birefringent properties, which in turn results in a high degree of their angular compensation.Type: ApplicationFiled: May 9, 2006Publication date: March 12, 2009Inventors: Janez Pirs, Silvija Pirs, Bojan Marin, Andrej Vrecko
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Patent number: 7420631Abstract: A new concept of the normally open LCD light switching element is proposed, which allows for the superior angular compensation for the light attenuation by using a single simple negative bireffingent c-plate compensation layer. The concept is based on the simultaneous use of highly angularly symmetric STN LC-configuration (preferably 180° twist) and maximal use of the single (preferably ordinary ray) light propagation mode. The solution is best suitable for various light switching applications like LCD automatic protective welding light filters, as well as for multi-segment large display panels, where it provides for excellent uniformity of the light-attenuation in the “dark” state.Type: GrantFiled: April 14, 2004Date of Patent: September 2, 2008Assignee: Institut Jozef StefanInventors: Janez Pirs, Matej Bazec, Silvija Pirs, Bojan Marin, Andrej Vrecko
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Publication number: 20070273811Abstract: A new concept of the normally open LCD light switching element is proposed, which allows for the superior attenuation by using a single simple negative bireffingent c-plate compensation layer. The concept is based on the simultaneous use of highly angularly symmetric S LC-configuration (preferably 180° twist) and maximal use of the single (preferably ordinary ray) light propagation mode. The solution is best suitable for various light switching applications like LCD automatic protective welding light filters, as well as for multi-segment large display panels, where it provides for excellent uniformity of the light-attenuation in the “dark” state.Type: ApplicationFiled: April 14, 2004Publication date: November 29, 2007Inventors: Janez Pirs, Matej Bazec, Silvija Pirs, Bojan Marin, Andrej Vrecko
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Patent number: 7132133Abstract: This invention solves the technical problem of compensating for the angular dependence of the contrast in optical devices comprising liquid crystal displays (LC optical light shutters, which operate on the principle of electrically controlled optical birefringence), with the aid of a compensation layer exhibiting optically negative birefringence, which enables the angular compensation of the LC layer birefringence in the state in which the LC molecules are homeotropically aligned (typical optically positive birefringence). The process for the manufacture of the optically negatively birefringent compensation layer is devised on the controlled spontaneous deformation of the polymer molecules during the polymerization procedure. The manufacturing process is feasible by the employment of known and well-controllable technical procedures, and enables the mass production of compensation layers.Type: GrantFiled: June 12, 2000Date of Patent: November 7, 2006Assignee: Institut Jozef StefanInventors: Janez Pir{hacek over (s)}, Silva Pir{hacek over (s)}, Bojan Marin, Robert Blinc, Martin Copic, Rok Petkov{hacek over (s)}ek
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Patent number: 7061462Abstract: The invention relates to the problem of the driving of the LCD electrooptic-switching element (1) with alternating, square-wave electric signals, the amplitude of witch can vary between different voltage levels in correspondence with the actual functioning state of the LCD electrooptic-switching element. The polarity changes of the electric driving signals is controlled by the integrator (9), integrating the difference of the electric potentials on the driving electrodes (2, 3) of the LCD electrooptic-switching element, in such a way that the value of time integral of the driving electric field is always kept within a selected interval. Besides this the time dependence of the electric driving signals can be optionally modified so that with every change of the polarity of the electric driving signals, the potentials on both driving electrodes get the same value for a time, which is significantly shorter than the switching time of the LCD electrooptic switching element.Type: GrantFiled: October 25, 1999Date of Patent: June 13, 2006Inventors: Janez Pir{hacek over (s)}, Bojan Marin, Sivija Pir{hacek over (s)}, Du{hacek over (s)}an Ponikvar
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Patent number: 5504600Abstract: An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal. The polymer which stabilizes the liquid crystal is formed by a method which includes introducing a mixture of a monomer and a ferroelectric liquid crystal between cell walls when the liquid crystal is in the isotropic phase, cooling the liquid crystal to a chiral nematic or smectic phase, and polymerizing the monomer. The cooling of the mixture can be done in the presence of a magnetic or electric field.Type: GrantFiled: April 11, 1995Date of Patent: April 2, 1996Assignee: Kent State UniversityInventors: Janez Pirs, Robert Blinc, Slobodan Zumer, Igor Musevic, Bojan Marin, Silva Pirs, Joseph W. Doane
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Patent number: 5434685Abstract: An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal.Type: GrantFiled: December 22, 1993Date of Patent: July 18, 1995Assignee: Kent State UniversityInventors: Janez Pirs, Robert Blinc, Slobodan Zumer, Igor Musevic, Bojan Marin, Silva Pirs, Joseph W. Doane
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Patent number: 5040877Abstract: The invention provides a low loss liquid crystal modulator for coloring and shaping a light beam wherein liquid crystal light modulators provide continuous variation in color and intensity output by controlled scattering; the liquid crystal light modulators comprise addressable sheets of light-wave-length size liquid crystal occlusious in a transparent matrix; the modulators employ nematic liquid crystal exhibiting positive dielectric anisotropy; the modulator is employed in varying and coloring output beams to allow for colored data or video transmission; images produced may vary in time as is required for, e.g., color television; the modulator is employed in color projectors for both data and video projection, for color printing, and for colored stage illumination. Low loss transmission of the modulators provides for bright images which can be viewed under high ambient illumination.Type: GrantFiled: December 4, 1987Date of Patent: August 20, 1991Assignee: Kent State UniversityInventors: Robert Blinc, J. William Doane, Bojan Marin, Igor Musevic, Janez Pirs, Silva Pirs, Slobodan Zumer, Samo Kopac
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Patent number: 4741600Abstract: In a LC matrix display with an internal reflector and an internal measuring reticle metal electrodes made of chromium, nickel, aluminum or some other metal are used as the internal reflector. By a special configuration of electrodes it is achieved that the measuring reticle is formed in the LC layer itself as a consequence of the optical effects in the liquid crystal. By building in an internal reflector and an internal measuring reticle any parallax is removed when observing the signal curve as well as the measuring reticle and, additionally, a maximum viewing angle is assured.Type: GrantFiled: November 5, 1986Date of Patent: May 3, 1988Assignee: Iskra-Sozd Elektrokovinske Industrije n.sol.o.Inventors: Janez Pirs, Bojan Marin, Igor Musevic, Silva Pirs, Andrej Gartner