6557 results about "Scattered light" patented technology

The invention features a reflective display device and a method of making a reflective display device that has reduced light loss and / or pixel cross talk due to internal reflection. The device includes a window layer, a plurality of reflective particles, a material portion disposed between the window layer and the plurality of reflective particles, and a refractive layer disposed between the window and the material portion. The plurality of reflective particles scatters light received from the ambient environment. The window layer has an index of refraction that is greater than an index of refraction of the ambient environment. The refractive layer has an index of refraction that is less than the index of refraction of the window layer and less than an index of refraction of the material portion.

Light emitted from a white LED 15 is converted by a lens 11 into light having an excellent directionality. The light illuminates a display panel 863 from the direction of an angle θk. The display panel 863 is a polymer dispersed liquid crystal display panel in a normally white mode. The display panel 863 modulates incident light by scattering it, the scattered light is incident on a magnification lens 866, and light from the magnification lens reaches an eye 21 of the observer. Light which passes straight through a liquid crystal layer in the display panel 863 is absorbed by an optical absorbing film 12. The observer fixedly positions his / her eye 21 to an eyepiece cover 852 and observes the displayed image.

A scanning endoscope, amenable to both rigid and flexible forms, scans a beam of light across a field-of-view, collects light scattered from the scanned beam, detects the scattered light, and produces an image. The endoscope may comprise one or more bodies housing a controller, light sources, and detectors; and a separable tip housing the scanning mechanism. The light sources may include laser emitters that combine their outputs into a polychromatic beam. Light may be emitted in ultraviolet or infrared wavelengths to produce a hyperspectral image. The detectors may be housed distally or at a proximal location with gathered light being transmitted thereto via optical fibers. A plurality of scanning elements may be combined to produce a stereoscopic image or other imaging modalities. The endoscope may include a lubricant delivery system to ease passage through body cavities and reduce trauma to the patient. The imaging components are especially compact, being comprised in some embodiments of a MEMS scanner and optical fibers, lending themselves to interstitial placement between other tip features such as working channels, irrigation ports, etc.

In one embodiment of this invention, a lightguide comprises a low refractive index region disposed between light extracting region and a non-scattering region. In further embodiment of this invention, volumetric scattering lightguide comprises a low refractive index region disposed between a volumetric scattering region and a non-scattering region. In some embodiments, a light emitting device comprising a volumetric scattering lightguide can angularly filter light input into the edge of a volumetric scattering lightguide by controlling the refractive index of the low refractive index region relative to the refractive index of the non-scattering region to prevent direct illumination of the volumetric scattering region, provide a luminance uniformity greater than 70%, or improve the angular luminous intensity of the light emitting device. The volumetric scattering lightguide may be curved, tapered, and a light emitting device comprising the same may further comprise at least one light source and a light redirecting element.

A method and apparatus are provided for the determination of levels of carotenoids and similar chemical compounds in biological tissue such as living skin. The method and apparatus provide a noninvasive, rapid, accurate, and safe determination of carotenoid levels which in turn can provide diagnostic information regarding cancer risk, or can be a marker for conditions where carotenoids or other antioxidant compounds may provide diagnostic information. Such early diagnostic information allows for the possibility of preventative intervention. The method and apparatus utilize the technique of resonance Raman spectroscopy to measure the levels of carotenoids and similar substances in tissue. In this technique, laser light is directed upon the area of tissue which is of interest. A small fraction of the scattered light is scattered inelastically, producing the carotenoid Raman signal which is at a different frequency than the incident laser light, and the Raman signal is collected, filtered, and measured. The resulting Raman signal can be analyzed such that the background fluorescence signal is subtracted and the results displayed and compared with known calibration standards.

An Optical Coherence Tomography (OCT) device irradiates a biological tissue with low coherence light, obtains a high resolution tomogram of the inside of the tissue by low-coherent interference with scattered light from the tissue, and is provided with an optical probe which includes an optical fiber having a flexible and thin insertion part for introducing the low coherent light. When the optical probe is inserted into a blood vessel or a patient's body cavity, the OCT enables the doctor to observe a high resolution tomogram. In a optical probe, generally, a fluctuation of a birefringence occurs depending on a bend of the optical fiber, and this an interference contrast varies depending on the condition of the insertion. The OCT of the present invention is provided with polarization compensation means such as a Faraday rotator on the side of the light emission of the optical probe, so that the OCT can obtain the stabilized interference output regardless of the state of the bend.

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.

Methods and apparatus for rendering quantitative phase maps across and through transparent samples. A broadband source is employed in conjunction with an objective, Fourier optics, and a programmable two-dimensional phase modulator to obtain amplitude and phase information in an image plane. Methods, referred to as Fourier transform light scattering (FTLS), measure the angular scattering spectrum of the sample. FTLS combines optical microscopy and light scattering for studying inhomogeneous and dynamic media. FTLS relies on quantifying the optical phase and amplitude associated with a coherent image field and propagating it numerically to the scattering plane. Full angular information, limited only by the microscope objective, is obtained from extremely weak scatterers, such as a single micron-sized particle. A flow cytometer may employ FTLS sorting.

A method for inspecting semiconductor wafers is provided in which a plurality of independent, low-cost, optical-inspection subsystems are packaged and integrated to simultaneously perform parallel inspections of portions of the wafer, the wafer location relative to the inspection being controlled so that the entire wafer is imaged by the system of optical subsystems in a raster-scan mode. A monochromatic coherent-light source illuminates the wafer surface. A darkfield-optical system collects scattered light and filters patterns produced by valid periodic wafer structures using Fourier filtering. The filtered light is processed by general purpose digital-signal processors. Image subtraction methods are used to detect wafer defects, which are reported to a main computer to aid in statistical process control, particularly for manufacturing equipment.

A fingerprint input apparatus includes an image sensor which responds to scattered light emanating from a finger. The scattered light is generated inside a finger having a fingerprint pattern in accordance with external light. The sensor may be a two-dimensional image sensor made of a large number of light-receiving elements arranged in a two-dimensional array or a one-dimensional sensor made of a large number of light-receiving elements arranged in a line-type array. In the latter case, the fingerprint is input by swiping the finger across the image sensor and reconstructing the fingerprint image. The fingerprint input apparatus is used to control use of a variety of devices, including electronic devices such as cellular telephones and personal computers, and access to buildings, rooms, safes and the like. The fingerprint input apparatus makes possible the elimination of personal identification numbers (PINs) and signatures in a variety of transactions.

Method and system are disclosed for de-embedding optical component characteristics from optical device measurements. In particular, the invention uses frequency domain averaging of the RBS on both sides of an optical component to determine one or more of its optical characteristics. Where the RBS has a slope (e.g., as in the case of a lossy fiber), a frequency domain least square fit can be used to determine the optical component characteristics. In addition, the invention uses a reference DUT to correct for variations in the frequency response of the photoreceiver. A reference interferometer is used in the invention to correct for sweep non-linearity of the TLS. The optical component characteristics are then de-embedded from optical device measurements to provide a more precise analysis of the optical device.

A light source injects light into a translucent light guide, particularly using high-power LEDs. A core to the light guide contains a homogenous mixture of fluid and a light dispersing agent to effect scattering. Scattered light passes though the light guide and may be used for illumination. A high power LED is provided with a reflector and heat sink to disperse waste heat, increasing the efficiency and life of the LED.

A system for treating a selected dermatologic problem and a head for use with such system are provided. The head may include an optical waveguide having a first end to which EM radiation appropriate for treating the condition is applied. The waveguide also has a skin-contacting second end opposite the first end, a temperature sensor being located within a few millimeters, and preferably within 1 to 2 millimeters, of the second end of the waveguide. A temperature sensor may be similarly located in other skin contacting portions of the head. A mechanism is preferably also provided for removing heat from the waveguide and, for preferred embodiments, the second end of the head which is in contact with the skin has a reflection aperture which is substantially as great as the radiation back-scatter aperture from the patient's skin. Such aperture may be the aperture at the second end of the waveguide or a reflection plate or surface of appropriate size may surround the waveguide or other light path at its second end. The portion of the back-scattered radiation entering the waveguide is substantially internally reflected therein, with a reflector being provided, preferably at the first end of the waveguide, for returning back-scattered light to the patient's skin. The reflector may be angle dependent so as to more strongly reflect back scattered light more perpendicular to the skin surface than back scattered radiation more parallel to the skin surface. Controls are also provided responsive to the temperature sensing for determining temperature at a predetermined depth in the patient's skin, for example at the DE junction, and for utilizing this information to detect good thermal contact between the head and the patient's skin and to otherwise control treatment. The head may also have a mechanism for forming a reflecting chamber under the waveguide and drawing a fold of skin therein, or for providing a second enlarged waveguide to expand the optical aperture of the radiation.

A method and apparatus are disclosed for evaluating relatively small periodic structures formed on semiconductor samples. In this approach, a light source generates a probe beam which is directed to the sample. In one preferred embodiment, an incoherent light source is used. A lens is used to focus the probe beam on the sample in a manner so that rays within the probe beam create a spread of angles of incidence. The size of the probe beam spot on the sample is larger than the spacing between the features of the periodic structure so some of the light is scattered from the structure. A detector is provided for monitoring the reflected and scattered light. The detector includes multiple detector elements arranged so that multiple output signals are generated simultaneously and correspond to multiple angles of incidence. The output signals are supplied to a processor which analyzes the signals according to a scattering model which permits evaluation of the geometry of the periodic structure. In one embodiment, the sample is scanned with respect to the probe beam and output signals are generated as a function of position of the probe beam spot.

A method of and apparatus for measuring line profile asymmetries in microelectronic devices comprising directing light at an array of microelectronic features of a microelectronic device, detecting light scattered back from the array comprising either or both of one or more angles of reflection and one or more wavelengths, and comparing one or more characteristics of the back-scattered light by examining data from complementary angles of reflection or performing a model comparison.

A light guide plate includes (i) a first light guide layer made of a material having a refractive index n1, and (ii) a scattering light guide layer having a function of scattering light. A reflection means for irradiating the scattering light guide layer with the light having propagated in the first light guide layer is provided on a surface opposite to a light guide surface of the first light guide layer, the light guide surface on which the light is incident. The scattering light guide layer includes at least (i) a second light guide layer made of a material having a refractive index n2 (n2<n1), and (ii) a scattering layer for scattering the light propagating in the second light guide layer.

A speckle readhead includes a light source that outputs light towards an optically rough surface. Light scattered from this surface contains speckles. The scattered light is imaged onto an image detector, captured and stored. Subsequently, a second image is captured and stored. The two images are repeatedly compared at different offsets in a displacement direction. The comparison having the highest value indicates the amount of displacement between the readhead and the surface that occurred between taking the two images. An optical system of the readhead includes a lens and an aperture. The aperture can be round, with a diameter chosen so that the average size of the speckles is approximately equal to, or larger than, the dimensions of the elements of the image detector. The dimension of the aperture in a direction perpendicular to the direction of displacement can be reduced. Thus, the imaged speckles in that direction will be greater than the dimension of the image detector elements in that direction. Such a readhead is relatively insensitive to lateral offsets. The lens can be a cylindrical lens that magnifies the relative motion along the direction of displacement but does not magnify relative motions in the direction perpendicular to the direction of displacement. The optical system can also be telecentric. Thus, the readhead is relatively insensitive to both separation and relative motions between the readhead and the surface. The light source can be modulated to prevent smearing the speckles across the image detector. The light source can be strobed to freeze the image.

The invention relates generally to methods of monitoring and controlling the processing of blood and blood samples, particularly the separation of blood and blood samples into its components. In one aspect, the invention relates to optical methods, devices and device components for measuring two-dimensional distributions of transmitted light intensities, scattered light intensities or both from a separation chamber of a density centrifuge. In embodiment, two-dimensional distributions of transmitted light intensities, scattered light intensities or both measured by the methods of the present invention comprise images of a separation chamber or component thereof, such as an optical cell of a separation chamber. In another aspect, the present invention relates to multifunctional monitoring and control systems for blood processing, particularly blood processing via density centrifugation. Feedback control systems are provided wherein two-dimensional distributions of transmitted light intensities, scattered light intensities or both are measured, processed in real time and are used as the basis of output signals for controlling blood processing. In another aspect, optical cells and methods of using optical cells for monitoring and control blood processing are provided.

An in vivo imaging device having an illumination system that creates a virtual source within a tissue region of a subject in a non-invasive manner. The illumination system transforms a maximum amount of illumination energy from a light source into a high contrast illumination pattern. The illumination pattern is projected onto the object plane in a manner that maximizes the depth to which clear images of sub-surface features can be obtained. The high intensity portion of the illumination pattern is directed onto the object plane outside the field of view of an image capturing device that detects the image. In this configuration, scattered light from within the tissue region interacts with the object being imaged. This illumination technique provides for a high contrast image of sub-surface phenomena such as vein structure, blood flow within veins, gland structure, etc.

An LED light-mixing package providing white light has at least a red LED chip, at least a blue LED chip, at least a green LED chip, and pluralities of diffuser particles distributed in a sealing member that covers the LED chips, or integrate a lens. The diffuser particles scatter light emitted from the LED chips in the sealing member so that light is mixed and the LED light-mixing package produces white light.

Blood sugar levels are measured non-invasively based on temperature measurement. Values of blood sugar levels non-invasively measured by a temperature measuring system are corrected using blood oxygen saturation and blood flow volume. Optical sensors are provided for detecting scattered light, reflected light, and light that enters into the skin which travels out of the body surface. The measurement data is stabilized by taking into consideration the influence of the thickness of skin on blood oxygen saturation.

A backlight apparatus has a collimating waveguide with a light input end, a top surface, a bottom surface, opposing sides, a far end opposite the light input end, and a total internal reflection critical angle for the material of the waveguide. A plurality of first facets are formed in the bottom surface distributed along the waveguide between the light input end and the far end. Each of the first facets has a first facet bottom surface which converges toward the top surface in a direction away from the far end relative to the top surface. A light scattering and reflective surface is disposed adjacent the far end of the collimating waveguide. The first facet bottom surfaces cause light rays entering the light input end to be totally internally reflected to the far end of the collimating waveguide wherein the scattering and reflective surface at the far end reflects and scatters light rays incident thereon back toward the light input end. The first facet bottom surfaces then cause the light rays reflected from the far end to exit the top surface. The first facet bottom surfaces may be formed either as straight facets or as curved surface facets and may also be alternatively formed having a reflective material layer thereon.

Methods and apparatus for in vitro detection of an analyte in a blood sample using low resolution Raman spectroscopy are disclosed. The blood analyzer includes a disposable strip for receiving a sample of blood on a target region, the target region including gold sol-gel to provide surface enhanced Raman scattering. A light source irradiates the target region to produce a Raman spectrum consisting of scattered electromagnetic radiation that is separated into different wavelength components by a dispersion element. A detection array detects a least some of the wavelength components of the scattered light and provides data to a processor for processing the data. The results of the processed data are displayed on a screen to inform a user about an analyte within the blood sample.

The present invention provides an down hole apparatus and method for ultrahigh resolution spectroscopy using a tunable diode laser (TDL) for analyzing a formation fluid sample downhole or at the surface to determine formation fluid parameters. In addition to absorption spectroscopy, the present invention can perform Raman spectroscopy on the fluid, by sweeping the wavelength of the TDL and detecting the Raman-scattered light using a narrow-band detector at a fixed wavelength. The spectrometer analyzes a pressurized well bore fluid sample that is collected downhole. The analysis is performed either downhole or at the surface onsite. Near infrared, mid-infrared and visible light analysis is also performed on the sample to provide an onsite surface or downhole analysis of sample properties and contamination level. The onsite and downhole analysis comprises determination of aromatics, olefins, saturates, gas oil ratio, API gravity and various other parameters which can be estimated by correlation, a trained neural network or a chemometric equation.

A method for obtaining an image of tooth tissue directs incident light toward a tooth (20), wherein the incident light excites a fluorescent emission from the tooth tissue. Specular reflection of incident light from the tooth tissue is reduced. Fluorescence image data (50) is obtained from the fluorescent emission. Back-scattered reflectance image data (52) is obtained from back-scattered light from the tooth tissue. The fluorescence and back-scattered reflectance image data are combined to form an enhanced image (64) of the tooth tissue for caries detection.

Transillumination imaging instrumentation is improved by eliminating the detection of stray light beams, and facilitating the detection of light beams which pass straight through an illuminated object. Three dimensional images can be constructed using either curved emitter and detector arrays or by using emitter and detector elements that rotate about a common axis.

An in vivo imaging device having an illumination system that creates a virtual source within a tissue region of a subject in a non-invasive manner. The illumination system transforms a maximum amount of illumination energy from a light source into a high contrast illumination pattern. The illumination pattern is projected onto the object plane in a manner that maximizes the depth to which clear images of sub-surface features can be obtained. The high intensity portion of the illumination pattern is directed onto the object plane outside the field of view of an image capturing device that detects the image. In this configuration, scattered light from within the tissue region interacts with the object being imaged. This illumination technique provides for a high contrast image of sub-surface phenomena such as vein structure, blood flow within veins, gland structure, etc.

Methods for enhancing the dynamic range for specific detection of one or more analytes in assays using scattered-light detectable particle labels. The methods involve utilizing variations in detection technique and / or signal processing to extend the dynamic range to either or both of lower and higher concentrations.