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15179 results about "Light guide" patented technology

Enhanced LCD backlight

ActiveUS20060056166A1Improved backlight assemblyAvoid less flexibilityElectric discharge tubesDiffusing elementsCompression moldingEllipsoidal particle
The present invention provides an improved light guide with inherently more flexibility for display system designers and higher optical efficiency. By using a light guide containing substantially aligned non-spherical particles, more efficient control of the light scattering can be achieved. One or more regions containing ellipsoidal particles may be used and the particle sizes may vary between 2 and 100 microns in the smaller dimension. The light scattering regions may be substantially orthogonal in their axis of alignment. Alternatively, one or more asymmetrically scattering films can be used in combination with a backlight light guide and a reflector to produce an efficient backlight system. The light guides may be manufactured by embossing, stamping, or compression molding a light guide in a suitable light guide material containing asymmetric particles substantially aligned in one direction. The light scattering light guide or non-scattering light guide may be used with one or more light sources, collimating films or symmetric or asymmetric scattering films to produce an efficient backlight that can be combined with a liquid crystal display or other transmissive display. By maintaining more control over the scattering, the efficiency of the recycling of light by using reflective polarizers can also be increased.
Owner:MASSACHUSETTS DEV FINANCE AGENCY

Planar light source device having polarization separator formed of two sheets with mating triangular prisms and different indices of refraction

The purpose of the invention is to provide a light guide of a variety of forms having a uniform distribution of brightness in the plane and a planer light source device for a liquid crystal display device which uses such light guide. The light guide comprises a first surface which is a surface to which a natural polarization light is incident and a second surface other than the first surface which is an exit surface of a specific polarization light into which, said natural polarization light is modulated, wherein;said light guide has an interface of two materials of different indices of refraction oriented at an angle of thetaB+/-alpha degrees relative to the primary propagation direction of said incident light, said thetaB being an angle satisfying Brewster's condition, more than two orientations of said interface exist in a single light guide, and the difference between the indices of refraction of the two materials of different indices of refraction is between 0.001 and 1.0. thetaB is typically about 45 degrees. The light guide comprises a first transparent member having a plurality of upwardly convex right angle isosceles triangles on a first surface thereof and a first index of refraction and a second transparent member having a plurality of downwardly convex right angle isosceles triangles on a second surface thereof and a second index of refraction, and said first surface and said second surface contact each other.
Owner:SEKISUI CHEM CO LTD +1

Information system and method for providing information using a holographic element

In the following, the essential points are summarized again by means of groups of characteristics which each individually and in combination with one another characterize the invention specifically: 1. Information system for providing information in correlation with light incident on an eye, having a holographic element disposed in front of the eye, and an optical scanning device which detects light incident on the eye by way of the holographic element. 2. Information system according to Point 1, wherein the optical scanning device is at a fixed predetermined angular ratio with respect to the holographic element. 3. Information system according to Point 1 or 2, wherein the optical scanning device detects light which is refracted by the holographic element before it impinges on the eye and does not enter the eye. 4. Information system according to one of the preceding points, wherein the optical scanning device detects light which was first reflected back from the eye and was then refracted by the holographic element. 5. Information system according to one of the preceding points, wherein the holographic element refracts light originating from the field of vision of the eye only at several discrete wavelengths in the visible range before the light impinges on the eye for the detection by the optical scanning device, and refracts light reflected back from the eye only at one discrete wavelength in the infrared range for the detection by the optical scanning device. 6. Information system according to one of the preceding points, wherein the holographic element refracts light originating from the field of vision of the eye at fewer than 20, fewer than 10 or fewer than 5 discrete wavelengths in the visible range either before the light impinges on the eye or after its backscattering as a result of the eye for the detection by the optical scanning device. 7. Information system according to one of the preceding points, wherein the holographic element refracts light originating from the field of vision of the eye at a discrete wavelength in the infrared range either before the light impinges on the eye or after its backscattering as a result of the eye for the detection by the optical scanning device. 8. Information system according to one of the preceding points, wherein the holographic element refracts light reflected back by the eye only at a discrete wavelength in the infrared range for the detection by the optical scanning device. 9. Information system according to one of the preceding points, wherein the holographic element refracts light of one or several discrete wavelengths, at which the optical scanning device has a high sensitivity. 10. Information system according to one of the preceding points, wherein the holographic element refracts light a several discrete wavelengths such that the refracted light is guided to a common point, and the angle of incidence of the light on this point permits a clear optionally also wavelength-independent conclusion on the angle of incidence of the light upon the holographic element. 11. Information system according to one of the preceding points, having an optical projection device which projects light into the eye by way of the holographic element. 12. Information system according to Point 11, wherein the light detected by the optical detection device and the light projected in front of the optical projection device run in the opposite direction through a common light guiding lens system and can be focused such by the optical scanning device or projection device that their respective beams describe the same path from or into the eye. 13. Information system for providing information in correlation with information obtained from an eye, having a holographic element disposed in front of the eye, and an optical projection device which projects light into the eye by way of the holographic element. 14. Information system according to one of Points 11 to 13, wherein the optical projection device projects light only at one or several discrete wavelengths in the visible range and/or at a wavelength in the infrared range. 15. Information system according to one of Points 11 to 14, wherein the holographic element refracts the wavelengths of the projected light. 16. Information system according to one of Points 11-15, wherein the optical projection device is in a fixed predetermined angular ratio with respect to the holographic element. 17. Information system according to Point 16, wherein the holographic element comprises one or more optical flags, whose light reflection characteristics can be used by the information system by means of a photodetector for calibrating a projection angle of the optical projection device and/or a light guiding device. 18. Information system according to Point 17, including Point 12, wherein the information system uses the light reflection characteristics of the optical flags for calibrating a scanning angle of the optical scanning device and/or a light guiding device. 19. Information system according to Point 17, wherein the optical flags are generated in that reflecting elements are imaged during the creating of the holographic element such in the holographic element that they (something is missing) reflect light of one or several wavelengths which, corresponding to the predetermined angular ratio with respect to the optical projection device is incident on the holographic element, back along the path of incidence. 20. Information system according to Point 19, wherein the photodetector device has a splitter mirror which is arranged such in the light beam of the optical projection device that it guides a portion of the light, which impinges on the splitter mirror against the projection direction, in the direction of a photodetector which detects in at least two areas situated concentrically around one another. 21. Information system according to one of the preceding points, wherein the holographic element has light-refracting characteristics at one or several discrete wavelengths, which correspond to a reflection on the concave side of an area constructed according to the curvature of a rotationally symmetrical ellipsoid. 22. Information system according to one of the preceding points, wherein the holographic element has light refracting characteristics at one or several discrete wavelengths, which correspond to a refraction on the concave side of an area constructed according to the curvature of a rotationally symmetrical ellipsoid, which refraction corresponds to a reflection on a respective conical surface which is rotationally symmetrical about the axis of rotation of the ellipsoid and is perpendicular with respect to the ellipsoid at the site of the refraction. 23. Method of providing information in correlation with light incident on an eye, whereby a holographic element is disposed in front of the eye, and an optical scanning device detects the light incident on the eye by means of the holographic element. 24. Method according to Point 23, whereby the optical scanning device is at a fixed predetermined angular ratio with respect to the holographic element. 25. Method according to Point 23 or 24, whereby the optical scanning device detects light which is refracted by the holographic element before impinging on the eye and does not enter the eye. 26. Method according to one of Points 23 to 25, whereby the optical scanning device detects light which was first reflected back from the eye and was then refracted by the holographic element. 27. Method according to one of Points 23 to 26, whereby the holographic element refracts light originating from the field of vision of the eye only at several discrete wavelengths in the visible range before its impinging on the eye for the detection by the optical scanning device and refracts light reflected back from the eye only at a discrete wavelength in the infrared range for the detection by the optical scanning device. 28. Method according to one of Points 23 to 27, whereby the holographic element refracts light originating from the field of vision of the eye at fewer than 20, fewer than 10 or fewer than 5 discrete wavelengths in the visible range either before its impinging on the eye or after its backscattering as a result of the eye for the detection by the optical scanning device. 29. Method according to one of Points 23 to 28, whereby the holographic element refracts light originating from the visual field of the eye at a discrete wavelength in the infrared range either before its impinging on the eye or after its backscattering as a result of the eye for the detection by the optical scanning device. 30. Method according to one of Points 23 to 29, whereby the holographic element refracts light reflected back from the eye only at a discrete wavelength in the infrared range for the detection by the optical scanning device. 31. Method according to one of Points 23 to 30, whereby the holographic element refracts light of one or several discrete wavelengths, at which the optical scanning device has a high sensitivity. 32. Method according to one of Points 23 to 31, whereby the holographic element refracts light at several discrete wavelengths such that the refracted light is guided to a common point, an the angle of incidence of the light onto this point allows a clear, optionally also wavelength-independent conclusion on the angle of incidence of the light upon the holographic element. 33. Method according to one of Points 23 to 32, whereby an optical projection device projects light by way of the holographic element into the eye. 34. Method according to Point 33, whereby the light detected by the optical scanning device and the light projected in front of the optical projection device run in the opposite direction through a common light guiding lens system and can be focused such by the optical scanning device or projection device that their respective beams describe the same path from or into the eye. 35. Method of providing information in correlation with information obtained from an eye, whereby a holographic element is disposed in front of the eye, and an optical projection device projects light by way of the holographic element into the eye. 36. Method according to points 33 to 35, whereby the optical projection device projects light only at one or several discrete wavelengths in the visible range and/or at a wavelength in the infrared range. 37. Method according to one of Points 33 to 36, whereby the holographic element refracts the wavelengths of the projected light. 38. Method according to one of Points 33 to 37, whereby the optical projection device is in a fixed predetermined angular ratio with respect to the holographic element. 39. Method according to Point 38, whereby the holographic element is equipped with one or more optical flags, whose light reflection characteristics can be used by means of a photodetector device for calibrating a projection angle of the optical projection device and/or a light guiding device. 40. Method according to Point 39, including Point 34, whereby the light reflection characteristics of the optical flags are used for calibrating a scanning angle of the optical scanning device and/or a light guiding device. 41. Method according to Point 39, whereby the optical flags are generated in that reflecting elements are imaged during the creating of the holographic element such in the holographic element that they beam light of one or more wavelengths which, corresponding to the predetermined angular ratio with respect to the optical projection device is incident on the holographic element, back along the incidence path. 42. Method according to Point 41, whereby the photodetector device is equipped with a photodetector detecting in at least two areas situated concentrically around one another, and a splitter mirror which is arranged such in the light beam of the optical projection device that it directs a portion of the light impinging on the splitter mirror against the projecting direction, in the direction of the photodetector. 43. Method according to one of Points 23 to 42, whereby the holographic element has light-refracting characteristics at one or several discrete wavelengths which correspond to a reflection on the concave side of an area constructed according to a curvature of a rotationally symmetrical ellipsoid. 44. Method according to one of Points 23 to 43, whereby the holographic element has light-refracting characteristics at one or several discrete wavelengths, which correspond to a refraction on the concave side of an area constructed according to a curvature of a rotationally symmetrical ellipsoid, which refraction corresponds to a reflection on a respective conical surface rotationally symmetrical about the axis of rotation of the ellipsoid, which conical surface is perpendicular with respect to the ellipsoid at the site of the refraction. While the preceding description with respect to the title is limited to embodiments falling under the initially mentioned generic terms “scanning information system” and “projecting information system”, each individual discussed characteristic of their disclosure can also be used in an embodiment of the systems, devices and methods initially identified by reference to their full content. The applications by the same applicant and/or the same inventors mentioned in the present application should be considered to be a correlated invention complex.
Owner:APPLE INC

Device for concentrating optical radiation

A holographic planar concentrator (HPC) for collecting and concentrating optical radiation is provided. The holographic planar concentrator comprises a planar highly transparent plate and at least one multiplexed holographic optical film mounted on a surface thereof. The multiplexed holographic optical film has recorded therein a plurality of diffractive structures having one or more regions which are angularly and spectrally multiplexed. Two or more of the regions may be configured to provide spatial multiplexing. The HPC is fabricated by: (a) recording the plurality of diffractive structures in the multiplexed holographic optical film employing angular, spectral, and, optionally, spatial multiplexing techniques; and (b) mounting the multiplexed holographic optical film on one surface of the highly transparent plate. The recording of the plurality of diffractive structures is tailored to the intended orientation of the holographic planar concentrator to solar energy. The HPC is mounted in the intended orientation for collecting solar energy and at least one solar energy-collecting device is mounted along at least one edge of the holographic planar concentrator. Examples of suitable solar energy-collecting devices include photovoltaic cells and fiber optic light guides for transmitting collected light into an interior of a building for illumination purposes and for transmitting collected solar radiation into a hot water tank for heating. The HPC permits efficient collection of solar energy without expensive requirements, while minimizing energy losses.
Owner:ILLINOIS INSTITUTE OF TECHNOLOGY

Laser diode optical transducer assembly for non-invasive spectrophotometric blood oxygenation monitoring

InactiveUS7047054B2Easily and securely attachedLight couplingDiagnostic recording/measuringSensorsCapacitanceFiber
A non-invasive near infrared spectrophotometric monitoring transducer assembly includes a housing member, which is adhered directly on a patient's skin. The housing member contains a prism coupled to a flexible and lightweight single core optical light guide, which provides a means of transferring narrow spectral bandwidth light from multiple distant laser diodes of different wavelengths by use of a multi-fiber optic light combining assembly. Different wavelengths are needed to monitor the level of blood oxygenation in the patient. The assembly also contains a planar light guide mounted on the prism located in the housing member, which light guide contacts the patient's skin when the housing member is adhered to the patient's skin. The light guide controls the spacing between the prism and the patient's skin, and therefore controls the intensity of the area on the patient's skin which is illuminated by the laser light. The housing member contains a photodiode assembly, which detects the infrared light at a second location on the skin to determine light absorption. The photodiode assembly is preferably shielded from ambient electromagnetic interference (EMI) by an optically transparent EMI attenuating window. This rigid window placed over the photodiode also provides a planar interface between the assembly and the skin, improving optical coupling and stability as well as reducing the capacitive coupling between skin and the photodiode resulting in further EMI attenuation. The housing may be associated with a disposable sterile hydrogel coated adhesive envelope, or pad, which when applied to the patient's skin will adhere the housing to the patient's skin. The transducer assembly will thus be reusable, and skin-contacting part of the device, i.e., the envelope or pad can be discarded after a single use. The assembly also includes a laser safety interlock means, which is operable to turn off the laser light output in the event that the assembly accidentally becomes detached from the patient's skin.
Owner:CAS MEDICAL SYST
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