Patents by Inventor Kenneth A. Epstein

Kenneth A. Epstein 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).

  • BRIGHTNESS ENHANCING FILM AND FILM BASED DIFFUSER FOR IMPROVED ILLUMINATION UNIFORMITY OF DISPLAYS
    Publication number: 20110037736
    Abstract: An optical device has a first film (200) that has a first side and a second side. When illuminated by light (204) at the first side, the first film is characterized by a first fraction of broadly diffused transmitted light (206) and a second fraction of narrowly diffused transmitted light (208). A second film (202) is disposed to the second side of the first film. The second film has at least one free surface that diverts light. In some embodiments, the first film has a diffuse scattering optical density between 0.5 and 3. The device finds use in spreading and making light uniform in a backlight in a display such as a liquid crystal display.
    Type: Application
    Filed: February 13, 2009
    Publication date: February 17, 2011
    Inventors: Kenneth A. Epstein, Stephan J. Etzkorn, Eric W. Nelson, Mark D. Gehlsen, Brian G. Koethe
  • Backlight with structured surfaces
    Patent number: 7873256
    Abstract: A backlight includes a lightguide, a light source disposed with respect to the lightguide to introduce light into the lightguide and a turning film. Optical structures are formed in one of an output surface and a back surface of the lightguide. The optical structures are arranged to extract light from the lightguide. A back reflector is disposed adjacent the back surface. The optical structures are formed to include a varying pattern arranged to mask non-uniformities in the output of the lightguide.
    Type: Grant
    Filed: September 14, 2005
    Date of Patent: January 18, 2011
    Assignee: 3M Innovative Properties Company
    Inventors: Mark E. Gardiner, Sanford Cobb, Jr., Kenneth A. Epstein, Wade D. Kretman
  • Back-lit displays with high illumination uniformity
    Patent number: 7789538
    Abstract: A directly illuminated display unit has a display panel and one or more light sources disposed behind the display panel. A diffuser is disposed between the one or more light sources and the display panel, and a light diverting layer is disposed between the one or more light sources and the diffuser. The light diverting layer has a first light-diverting surface facing the one or more light sources and a second light diverting surface facing the display panel. The light diverting layer diverts light passing from the one or more light sources to the diffuser, thus improving the uniformity of the light in the display unit.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: September 7, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: Kenneth A. Epstein, Kenneth J. Hanley
  • HIGHER TRANSMISSION LIGHT CONTROL FILM
    Publication number: 20100214506
    Abstract: A light control film, and light collimating assemblies and liquid crystal displays incorporating such light control films are described. The light control film includes alternating transmissive and absorptive regions, where the refractive index of each transmissive region is greater than the refractive index of each absorptive region. The absorptive regions form interfaces at angles that are close to the perpendicular to the light control film. A portion of the incident light intercepting the absorptive region undergoes Total Internal Reflection, and is transmitted through the film. The axial brightness of light passing through the film is increased, the brightness is more uniform within the viewing angle, and the viewing cutoff angle is sharpened.
    Type: Application
    Filed: October 13, 2008
    Publication date: August 26, 2010
    Inventors: Gary E. Gaides, Kenneth A. Epstein
  • Back-lit displays with high illumination uniformity
    Patent number: 7766528
    Abstract: A directly illuminated display unit has a display panel and one or more light sources disposed behind the display panel. A diffuser is disposed between the one or more light sources and the display panel, and a light diverting layer is disposed between the one or more light sources and the diffuser. The light diverting layer has a first light-diverting surface facing the one or more light sources and a second light diverting surface facing the display panel. The light diverting layer diverts light passing from the one or more light sources to the diffuser, thus improving the uniformity of the light in the display unit.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: August 3, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: Kenneth A. Epstein, Kenneth J. Hanley, Robert M. Emmons
  • LIQUID CRYSTAL DISPLAYS WITH LAMINATED DIFFUSER PLATES
    Publication number: 20100188754
    Abstract: In a liquid crystal display (LCD), for example an LCD monitor or an LCD-TV, a number of light management films, including a diffuser layer, lie between the light source and the LCD panel to provide bright, uniform illumination. In some embodiments, the diffuser layer is attached to the lower side of the LCD panel. Some, or all, of the light management layers may be attached together as a laminated stack of films. In some embodiments, the diffuser layer is formed with a recessed region on one side and another optical film positioned within the recessed region.
    Type: Application
    Filed: March 15, 2010
    Publication date: July 29, 2010
    Inventors: Mark D. Gehlsen, Linda M. Rivard, Ryan T. Fabick, James W. Laumer, Kenneth A. Epstein, Byung-soo Ko, Ji-Hyung Kim, Sang-Dae Kim, Ji-Hwa Lee
  • BACK-LIT DISPLAYS WITH HIGH ILLUMINATION UNIFORMITY
    Publication number: 20100135004
    Abstract: A directly illuminated display unit includes a display panel and one or more light sources disposed behind the display panel. The light sources are capable of producing illumination light. A diffusive light diverting layer is disposed between the one or more light sources and the display panel. The light diverting layer comprises first light diverting elements disposed on one of a first side of the light diverting layer facing display panel and second light diverting elements disposed on a second side of the light diverting layer facing away from the display panel. The diffusive light diverting layer further comprises diffusing particles disposed within a polymeric matrix.
    Type: Application
    Filed: November 14, 2007
    Publication date: June 3, 2010
    Inventors: Kenneth A. Epstein, Kenneth J. Hanley, Gary T. Boyd
  • CURVED SIDED CONE STRUCTURES FOR CONTROLLING GAIN AND VIEWING ANGLE IN AN OPTICAL FILM
    Publication number: 20100128351
    Abstract: A method of making an optical film includes the steps of making a substrate having a first major surface and a second major surface opposite the first surface and forming a plurality of curved sided cone structures on the first surface. Each of the curved sided cone structures include a base located on the first surface, a vertex, and a curved side formed from an arc extending between the base and the vertex. The optical gain and viewing angle for the film can be controlled by adjusting angles representing a shape of each curved sided cone structure at its vertex and base.
    Type: Application
    Filed: November 21, 2008
    Publication date: May 27, 2010
    Inventors: Kenneth A. Epstein, Timothy J. Hebrink, Charles D. Hoyle, Dale L. Ehnes, Michael P. Keyes, Thomas R. Corrigan, Randy S. Bay, Thomas R. Hoffend, JR.
  • Liquid crystal displays with laminated diffuser plates
    Patent number: 7710511
    Abstract: In a liquid crystal display (LCD), for example an LCD monitor or an LCD-TV, a number of light management films, including a diffuser layer, lie between the light source and the LCD panel to provide bright, uniform illumination. In some embodiments, the diffuser layer is attached to the lower side of the LCD panel. Some, or all, of the light management layers may be attached together as a laminated stack of films. In some embodiments, the diffuser layer is formed with a recessed region on one side and another optical film positioned within the recessed region.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: May 4, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: Mark D. Gehlsen, Linda M. Rivard, Ryan T. Fabick, James W. Laumer, Kenneth A. Epstein, Byung-soo Ko, Ji-Hyung Kim, Sang-Dae Kim, Ji-Hwa Lee
  • Illumination assembly and system
    Patent number: 7695180
    Abstract: Illumination assemblies and systems using same are disclosed. The illumination assembly can include a reflective substrate, and a light source unit including one or more light sources capable of producing illumination light. The assembly can further include a first light extraction surface including an azimuthal beam widening topography, where the first light extraction surface is positioned such that the light source unit is between the first light extraction surface and the reflective substrate. The first light extraction surface can face the light source unit.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: April 13, 2010
    Assignee: 3M Innovative Properties Company
    Inventors: Craig R. Schardt, D. Scott Thompson, Kenneth A. Epstein, Brian W. Ostlie, Richard F. Griffith, Kenneth L. Smith
  • LED emitter with radial prismatic light diverter
    Patent number: 7637639
    Abstract: An optical assembly includes a light emitting diode (LED) and a structured surface. The structured surface has a plurality of prismatic structures arranged radially with respect to a reference point, and is disposed relative to the LED such that the reference point is substantially aligned with a light emission axis of the LED. Arrays of such assemblies and backlights and displays including same are also disclosed.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: December 29, 2009
    Assignee: 3M Innovative Properties Company
    Inventor: Kenneth A. Epstein
  • DIRECT-LIT LIQUID CRYSTAL DISPLAYS WITH LAMINATED DIFFUSER PLATES
    Publication number: 20090122228
    Abstract: In a directly-illuminated liquid crystal display (LCD), for example an LCD monitor or an LCD-TV, a number of light management films, including a diffuser layer, lie between the light source and the LCD panel to provide bright, uniform illumination. The diffuser layer is attached to a substrate which is separate from the light source and the LCD panel, or may be attached to either the LCD panel or, when using a two dimensional light source, to the light source. The other light management layers may also be attached to the separate substrate or to the LCD panel or two-dimensional light source. High levels of illumination uniformity at the LCD may be achieved with a uniform (non-patterned) diffuser, even with relatively low levels of diffusion, when the diffuser is used with a brightness enhancing layer.
    Type: Application
    Filed: October 31, 2008
    Publication date: May 14, 2009
    Inventors: Byungsoo Ko, Mark D. Gehlsen, Chingwen Chen, Robert M. Emmons, James W. Laumer, Ji-Hyung Kim, Ji-Hwa Lee, Kang-il Seo, Ryan T. Fabick, Linda M. Rivard, Kenneth A. Epstein, Chideuk Kim, Youngsoo Park
  • STRUCTURED ORIENTED FILMS FOR USE IN DISPLAYS
    Publication number: 20090067048
    Abstract: Films having a structured surface with an engineered feature, such as prism grooves, to be used in displays having a backlight. The films can be arranged in a stack having one or more of the following: birefringent brightness enhancement films, non-birefringent brightness enhancement films, polarizers, diffusers, birefringent turning films, and non-birefringent turning films. Those films can be arranged in any order from the backlight to a viewer.
    Type: Application
    Filed: November 10, 2008
    Publication date: March 12, 2009
    Inventors: James M. Battiato, William W. Merrill, Leland R. Whitney, Kenneth A. Epstein, Robert L. Brott, Rolf W. Biernath, Mitsuko T. O'Neill, Stephen A. Johnson, Matthew B. Johnson, Daniel W. Hennen, William B. Black, Mark B. O'Neill, William J. Bryan, Dennis W. Wilson, Martin E. Denker, David A. Kowitz
  • Phosphor based illumination system having a long pass reflector and method of making same
    Patent number: 7497608
    Abstract: An illumination system including a light source, a light guide including an output surface, emissive material positioned between the light source and the output surface of the light guide, and an interference reflector positioned between the emissive material and the output surface of the light guide is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The interference reflector substantially transmits light having the second optical characteristic and substantially reflects light having the first optical characteristic.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: March 3, 2009
    Assignee: 3M Innovative Properties Company
    Inventors: John A. Wheatley, Andrew J. Ouderkirk, Michael F. Weber, Kenneth A. Epstein, James E. Watson
  • Back-lit displays with high illumination uniformity
    Patent number: 7478913
    Abstract: A directly illuminated display unit has a display panel and one or more light sources disposed behind the display panel. A diffuser is disposed between the light source unit and the display panel and a light diverting layer is disposed between the one or more light sources and the diffuser. The light diverting layer has light diverting members on a first side of the light diverting layer facing the diffuser. Surfaces of the light diverting members are disposed at more than one angle relative to a normal to the light diverting layer and also include one or more sharp changes of surface slope. The light diverting members spread the illumination light so as to be more uniform. Different light diverting members can have different apex angles. Also, different sides of a light diverting member can have best fit centers of curvature that are non-coincident.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: January 20, 2009
    Assignee: 3M Innovative Properties
    Inventors: Kenneth A. Epstein, Kenneth J. Hanley, James A. Stevenson, Robert M. Emmons
  • Direct-lit liquid crystal displays with laminated diffuser plates
    Patent number: 7446827
    Abstract: In a directly-illuminated liquid crystal display (LCD), for example an LCD monitor or an LCD-TV, a number of light management films, including a diffuser layer, lie between the light source and the LCD panel to provide bright, uniform illumination. The diffuser layer is attached to a substrate which is separate from the light source and the LCD panel, or may be attached to either the LCD panel or, when using a two dimensional light source, to the light source. The other light management layers may also be attached to the separate substrate or to the LCD panel or two-dimensional light source. High levels of illumination uniformity at the LCD may be achieved with a uniform (non-patterned) diffuser, even with relatively low levels of diffusion, when the diffuser is used with a brightness enhancing layer.
    Type: Grant
    Filed: October 15, 2004
    Date of Patent: November 4, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: Byungsoo Ko, Mark D. Gehlsen, Chingwen Chen, Robert M. Emmons, James W. Laumer, Ji-Hyung Kim, Ji-Hwa Lee, Kang-il Seo, Ryan T. Fabick, Linda M. Rivard, Kenneth A. Epstein, Chideuk Kim, Youngsoo Park
  • LED LIGHT EXTRACTION BAR AND INJECTION OPTIC FOR THIN LIGHTGUIDE
    Publication number: 20080260328
    Abstract: An optical system for back-illuminating a display has a lightguide having a confinement direction and a first plurality of light sources disposed proximate a first edge of the lightguide. Light from at least one of the light sources defines an emission axis which is approximately parallel to the confinement direction. A solid light injector is disposed to couple light from the light sources into the lightguide. A surface of the light injector may be shaped as a confinement curve for confining light from the first plurality of light sources in the confinement direction by total internal reflection. In some embodiments a portion of the illumination light from the one or more light sources enters the first light injector along a direction having a component directed away from the lightguide and is totally internally reflected within the injector.
    Type: Application
    Filed: April 20, 2007
    Publication date: October 23, 2008
    Inventor: Kenneth A. Epstein
  • LIGHTGUIDES HAVING CURVED LIGHT INJECTORS
    Publication number: 20080260329
    Abstract: An optical system has a lightguide having a confinement direction and a first light source disposed proximate a periphery of the lightguide. A light injector is disposed to couple light from the first light source into the lightguide. The light injector has a surface formed with a confinement curve for confining light in the confinement direction. The light injector may be disposed at either a recess on the periphery of the lightguide or at a cut corner of the lightguide. A refractive structure, having at least one surface non-perpendicular to an emission axis of the light source may be disposed between the injector and the lightguide. At least a portion of the injector may have a shape corresponding to a confinement curve that is rotated about an axis parallel to the confinement direction.
    Type: Application
    Filed: April 20, 2007
    Publication date: October 23, 2008
    Inventor: Kenneth A. Epstein
  • Composite diffuser plates and direct-lit liquid crystal displays using same
    Patent number: 7436469
    Abstract: In a directly-illuminated liquid crystal display (LCD), for example an LCD monitor or an LCD-TV, a number of light management layers lie between the light source and the LCD panel to provide bright, uniform illumination. The light management layers, including, for example, a diffuser, a reflective polarizer and a brightness enhancing layer, are contained in a light management unit that is formed from two subassemblies. The two subassemblies each contain a substrate and are attached together so as to leave a gap between the two subassemblies. The diffuser is located in one of the subassemblies, and the other light management layers may be in either of the subassemblies, or may be disposed in the gap between the subassemblies.
    Type: Grant
    Filed: October 15, 2004
    Date of Patent: October 14, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: Mark D. Gehlsen, Chingwen Chen, Byungsoo Ko, Robert M. Emmons, James W. Laumer, Ryan T. Fabick, Linda M. Rivard, Kenneth A. Epstein, Youngsoo Park, Chideuk Kim, James A. Stevenson
  • Phosphor based illumination system having a plurality of light guides and a display using same
    Patent number: 7407313
    Abstract: An illumination system including a light source, light guides coupled to the light source, each including an input surface and an output surface, emissive material positioned to receive light from at least one light guide, and a first interference reflector positioned between the emissive material and the output surfaces of the light guides is disclosed. The light source emits light having a first optical characteristic. The emissive material emits light having a second optical characteristic when illuminated with light having the first optical characteristic. The first interference reflector substantially transmits light having the first optical characteristic and substantially reflects light having the second optical characteristic.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: August 5, 2008
    Assignee: 3M Innovative Properties Company
    Inventors: Craig R. Schardt, John C. Schultz, Andrew J. Ouderkirk, John A. Wheatley, Michael F. Weber, Kenneth A. Epstein, James E. Watson