1138 results about "Light attenuation" patented technology

An apparatus and method for determining tissue oxygenation such as arterial and venous oxygenation and cerebral oxygenation. In one embodiment the optical properties of tissue are determined using measured light attenuations at a set of wavelengths. By choosing distinct wavelengths and using light attenuation information, the influence of variables such as light scattering, absorption and other optical tissue properties can be minimized.

An oxygen concentration measurement system for blood hemoglobin comprises a multiple-wavelength low-coherence optical light source that is coupled by single mode fibers through a splitter and combiner and focused on both a target tissue sample and a reference mirror. Reflections from both the reference mirror and from the depths of the target tissue sample are carried back and mixed to produce interference fringes in the splitter and combiner. The reference mirror is set such that the distance traversed in the reference path is the same as the distance traversed into and back from the target tissue sample at some depth in the sample that will provide light attenuation information that is dependent on the oxygen in blood hemoglobin in the target tissue sample. Two wavelengths of light are used to obtain concentrations. The method can be used to measure total hemoglobin concentration [Hb.sub.deoxy +Hb.sub.oxy ] or total blood volume in tissue and in conjunction with oxygen saturation measurements from pulse oximetry can be used to absolutely quantify oxyhemoglobin [HbO.sub.2 ] in tissue. The apparatus and method provide a general means for absolute quantitation of an absorber dispersed in a highly scattering medium.

A method of improving the lighting conditions of a real scene or video sequence. Digitally generated light is added to a scene for video conferencing over telecommunication networks. A virtual illumination equation takes into account light attenuation, lambertian and specular reflection. An image of an object is captured, a virtual light source illuminates the object within the image. In addition, the object can be the head of the user. The position of the head of the user is dynamically tracked so that an three-dimensional model is generated which is representative of the head of the user. Synthetic light is applied to a position on the model to form an illuminated model.

The invention provides an LED (Light Emitting Diode) lamp filament and a manufacturing method thereof. An LED chip is encapsulated on the edge top surface of a thin and long sheet metal support of the LED filament innovatively, meanwhile the sheet metal is inserted into a preformed transparent plastic model frame to produce a light source, and accordingly the automated continuous production of the LED lamp filament is implemented and the problem of the facing direction strength caused by the too thin and too long metal support is solved due to the transparent plastic model frame; meanwhile the lateral direction strength of the metal support is effectively utilized and accordingly the integral mechanical strength of the LED lamp filament is ensured; the heat dissipation characteristics of the metal is directly utilized, meanwhile the heat dissipation efficiency of the LED chip is maximized through the innovative encapsulation of thermal conductive coatings, and accordingly the problem of a heat dissipation bottleneck of the LED lamp filament is effectively solved, the LED lamp filament can work at the rated power for a long time, and the cost is reduced; the LED light extraction efficiency is improved, the light attenuation is reduced, the high lighting effect and ambient light of lamp filament light emission is implemented, and the market vacancy of the existing LED lamp filament is filled through innovative fluorescence encapsulation materials.

Shadows from physical lights have a penumbra region, in which the light is only partially hidden from the shadow acceptor. The intensity of light in this region may be calculated using an approximation of the amount of light visible. For example a fragment or pixel shader program execution on a GPU may generate a shadow from a light source using the light intensities for each pixel being rendered. Per-pixel shadow density information may be projected from the shadow caster onto the shadow acceptor. A penumbra map may contain both depth information and light attenuation information for the shadow acceptor. This information may be blurred using a fragment or pixel shader on a GPU to determine an average shadow density for a pixel being rendered.

A system for selectively attenuating light from a source of light, such as the sun, to a person's eyes in a vehicle. The system includes an electro-optical element (10) interposed between the source of light (16) and the person's eyes (14). The element (10) has pixels (18) that are operable to individually attenuate (38) light passing therethrough. A navigation system (28) determines a location and direction of travel of the vehicle. A memory (24) contains a general location for the person's eyes within the vehicle. Information (32) is made available for determining a position of the source of light. A controller (24) operates to determine those pixels of the elements that are calculated (38) to be between the person's eyes and the source of light, and to reduce the light transmittivity of those pixels (38) to attenuate the light from the source (16) to the person's eyes (14).

When a video signal is inputted to a projector (10) through a video input terminal, a luminance peak value of an image of the video signal is detected by an image-analyzing circuit (61) to be outputted to a CPU (71). A gain-adjusting circuit (63) adjusts a luminance signal in the video signal based on a command from the CPU (71). The CPU (71) determines a gain adjustment amount based on the luminance peak value of the image obtained by the image-analyzing circuit (61) and outputs the result to the gain-adjusting circuit (63). For instance, when the luminance peak value (lp) of the image is 50% of the upper limit (Imax) thereof, a gain-adjusting amount AG is doubled In this case, an illuminating light volume of a light valve (44a) has to be reduced to 50%, which is achieved by light-attenuation by a light-source lamp (21) and an open/close light shield (23).

An organic EL element of one pixel is selectively irradiated with laser light. With the laser irradiation, the functionality of the organic layer of the organic EL element is selectively degraded and the light emission capability is removed without damaging the cathode.

A vehicle imaging system includes an imaging device that images at least a part of an area around a vehicle; and a visible light attenuation device that attenuates part of visible light that enters the imaging device. The imaging device includes an imaging element that converts both of the infrared light and an infrared ray to electric signals. The imaging device outputs both of image data produced based on the electric signal to which the visible light, which has entered the imaging device without passing through the visible light attenuation device, has been converted, and image data produced based on the electric signal to which the infrared ray, which has passed through the visible light attenuation device, has been converted.

The invention discloses a solar cell with a composite dielectric passivation layer structure and a preparation process thereof. A silicon oxide film, an alumina film and a silicon nitride or silicon oxynitride film are deposited in turn on the front, back and sides of a p-type silicon substrate to form a composite dielectric film on the whole surface, and windows are opened locally to lead electrodes out. Through aluminum oxide, silicon dioxide, silicon oxynitride, silicon nitride with different refractive indexes and a back surface passivation layer with a laminated structure of the materials, the back surface recombination rate is greatly reduced, the back reflectivity is improved, the CTM of a module is reduced, and the light attenuation and heat-assisted light attenuation and the anti-PID performance of the cell are improved. The structure can be made on a boron/gallium-doped p-type monocrystalline silicon, p-type polycrystalline silicon or p-type monocrystalline-silicon-like substrate, and a passivation method based on the composite dielectric film passivation structure can be used to manufacture PERC cells, double-sided PERC+ cells and imbricate PERC cells. Based on the preparation process steps and sequence, the corresponding preparation mode and the process parameter range of the laminated structure, the making of the cell can be well completed.

A compound optical and electrical conductor includes a fiberoptic light transmitting element (multiple fibers or single solid rod) with at least one solar cell with LED therewith. The electrical conductor or conductors may be imbedded or otherwise secured within the optically conducting element or its surrounding jacket or sheath, or may be contained in a separate elongate retainer which may be provided to hold the optically conducting element in place as desired. The conductors may include a jacket or retainer which is optically open along one side thereof, allowing the optical conductor to emit light laterally therefrom subtending an angle defined by the optical gap in the jacket or retainer. One or more compound connectors may be provided, for linking two or more such compound conductors together as desired. The connectors provide for both the concentric alignment of the optical conductors, and also the electrical connection of the electrical conductors of the compound devices. The connectors preferably each include one or more lighting elements (halogen, high output LED, etc.) to compensate for light attenuation along the lengths of the attached optical conductors. The electrically conducting elements of the compound conductors provide electrical power to the lighting elements enclosed within the connectors, to provide an increase in light power at points along the length of an assembly. Different colors of lights may be provided, with the electrical conductors providing for the selective illumination of each as desired.

The invention discloses a gallium and indium doped single crystal silicon material for a solar battery, which consists of the following components according to atom number per cubic centimeter of the single crystal silicon material: 1.0X10<14> to 1.0X10<18> gallium, 5.0X10<12> to 5.0x10<16> indium and the balance of single crystal silicon. The invention also discloses a method for preparing the gallium and indium doped single crystal silicon material for the solar battery, which is implemented by the following steps of: dismantling a furnace by using a regular method, cleaning a hearth and assembling the furnace; vacuumizing the inside of a single crystal furnace and detecting the leakage of the single crystal furnace by using a regular method; pressuring materials and smelting the materials; stabilizing the melt; seeding crystals; performing shouldering; performing shoulder rotation; performing isodiametric growth; performing ending and cooling the obtained product; and stopping the furnace. The gallium and indium doped single crystal silicon material for the solar battery has the advantages of high conversion efficiency, low light attenuation, low oxide content in the single crystal silicon and uniform radial distribution in a single crystal silicon rod; and the preparation method of the invention effectively controls the thermal conversion of silicon melt and grows the high-quality gallium and indium doped single crystal silicon material for the solar battery.

A liquid crystal shutter glasses comprises a liquid crystal shutter placed within the view angle of the observer of a display apparatus wherein the liquid crystal shutter has an effective shutter region in which the transmission or shielding of incident light is controllable and a light attenuation region positioned outside the effective shutter region for attenuating incident light.

A method of fabricating a LED module by: bonding one or multiple LED chips and multiple conducting terminals to a circuit substrate, and then molding a packing cup on the circuit substrate over by over molding for enabling the LED chip(s) and the conducting terminals to be exposed to the outside of the packing cup, and then molding a lens on the packing cup and the LED chip(s) by over-molding. By means of directly molding the lens on the packing cup and the LED chip(s), no any gap is left in the lens, avoiding deflection, total reflection or light attenuation and enhancing luminous brightness and assuring uniform distribution of output light.

An extreme low resistivity light attenuation anti-reflection coating structure in order to increase transmittance of blue light, includes a substrate and a coating module. The coating module is formed on a front surface of the substrate and composed of a plurality of silicon carbide compound coating layers, a plurality of Al-based oxide coating layers and a plurality of metal coating layers that are alternately stacked onto each other.

Projection of a light field on a semiconductor wafer, the light field having uniform intensity and a predefined area. An aperture is placed within a light beam path, with a specifically designed three-dimensional profile, so as to shape the light beam in a specific manner. When this light beam is transmitted through the appropriate optics, its shape is altered so as to be projected onto the wafer as a circle (or any other desired shape). An optical mask is also employed, with a varying light attenuation to impart a varying intensity to the light path. The aperture shapes the light path, and the optical mask selectively attenuates it, in so that the end result is a uniformly-intense light field that illuminates only a specific predefined area of the wafer. Wafers can thus be illuminated while avoiding undesirable areas such as wafer edges, thus preventing over- or under-illumination.

It is an object of this invention to independently control the F-number and the number of light attenuation steps of a multi-density ND filter by using a light amount control apparatus using an iris stop and the ND filter. The iris stop mechanism made up of a plurality of aperture blades and the ND filter having a multi-density pattern are stacked in a single unit. This simultaneously realizes continuous control of the F-number, multi-step control of the light attenuation ratio of the ND filter, a substantially circular stop aperture, and a uniform transmittance distribution in the stop aperture. In the first embodiment, the driving region of an actuator is divided into an ND control region and aperture control region. This makes it possible to independently control the F-number and the number of ND steps by the single actuator.

The invention discloses a white light LED packaging structure comprising a bracket and a plurality of LED chips arranged on the bracket, wherein a heat-insulation transparent material layer is coatedon the LED chips, a fluorescent powder layer is also coated on the heat-insulation transparent material layer, and a light outlet face of the heat-insulation transparent material layer and the fluorescent powder layer directly form a lens structure, or a lens structure is arranged on the fluorescent powder layer. The number of the LED chip is multiple, the heat-insulation transparent material layer and the fluorescent powder layer are sequentially and independently coated on each LED chip, or the heat-insulation transparent material layer and the fluorescent powder layer are integrally coatedon each LED chip. The invention has low manufacturing cost, improves the problem of heat radiation of a high-power white light LED, reduces light attenuation and enables the light color to be more stable.