124 results about "Polarizing filter" patented technology

An endoscope includes an imaging device, a first polarizing filter disposed in front of the imaging device, a light source, and a second polarizing filter disposed in front of the light source. The planes of polarization of the first and second polarizing filters are at a substantially 90° angle.

A wavelength discriminating optical filter has birefringent retarders stacked between polarizing filters, in relative rotational orientations causing passband wavelengths to emerge in a polarization state aligned to a second such polarizing filter, for transmission, whereas wavelengths at orthogonal polarization states are blocked. The second polarizing filter can be a wiregrid type that reflects the blocked orthogonal component backwards along the light signal propagation path. Internal reflections are minimized while obtaining a high transmission ratio and high discrimination for the passband wavelengths, by pairing a zero-degree reflective polarizer as the second or selection polarizer, with a preceding non-zero-degree reflective polarizer. The non-zero-degree reflective polarizer can absorb the blocked orthogonal polarization components, for example using an oriented dichroic material, or a polarizing cube or the like can be provided to divert the blocked polarization component.

Reflective color filters using layers of cholesteric liquid crystals with two different center wavelengths and bandwidths per layer are stacked in two layers to provide colored light for displays. With a two layer stack circularly polarized light of one handedness can be provided. With a four layer stack unpolarized colored light can be provided. With a broadband polarizing filter overlapping other filters in the stack a black matrix can be provided by reflecting all colors and transmitting no light in the overlapping areas. When broadband reflective cholesteric liquid crystals are used two primary colors can be reflected in the same pixel of a display making reflective layers with two reflective portions per layer possible. Color displays having three linear sub-pixels with three primary colors or with four sub-pixels of white, blue, green, and red in a pixel with two colors in a top row and two colors on a bottom row can are made with two colors per layer in two layer stacks. The pixels in the display are arranged such that multiple adjacent sub-pixels in a layer, or row in a layer, with the same color makes the color filters easier to manufacture. Displays using these reflective color filters may have a reflective polarizer for viewing the display at wide angles without color distortion. A method of producing cholesteric liquid crystal color filters by polymerizing different portions of cholesteric liquid crystal mixtures at different temperatures and radiations to obtain different central wavelengths and bandwidths of reflection. By masking parts of a layer several portions with different colors are polymerized in a single layer. Further, with radiation which is attenuated in the cholesteric liquid crystal material stacks of different portions reflecting different colors in the same layer are made. Further the cholesteric liquid crystals are polymerized to have other optical properties in the stack such as quarter wave plates and broad band polarizers such that entire optical devices can be made in one layer of cholesteric liquid crystal material making the devices smaller, lighter, more robust, reliable, and easier to make by eliminating gluing and alignment problems. With overlapping reflective cholesteric liquid crystal which together reflect all light stacks with automatic black matrixes built into the layer are made saving light from being blocked by conventional black matrix light absorbing layers in display devices.

The present invention discloses a stereoscopic display employing polarized eyewear. The basic component of the present invention stereoscopic display is a stereopolarizer, which is a polarized screen comprising microscopic sections of mutually extinguishing polarizing filters dispersed throughout the screen. To achieve the proper resolution, the size of the microscopic polarizing filter needs to be in order of micrometer, from a few microns to a few hundred of microns. The arrangement of the microscopic polarizing filters can be alternating stripes in horizontal, vertical, or any arbitrarily direction. The microscopic polarizing filters can be arranged in alternating pattern, such as alternating square or circle. The polarizer screen can be one sheet or can be a composite sheet, comprising two distinct polarizer filter sheet laminated together. Laser drilling is used to fabricate the microscopic polarizing filters, primarily due to ease of operation and appropriate microscopic sizes. Further, laser drilling and cutting can form angle holes in the stereopolarizer, which provides optimum focus viewing for horizontal perspective display.

Adjacent pixels of an infrared focal plane array (IR FPA) can be configured to have different spectral or polarization responses by adjustment of the lengths or orientations of the antenna arms which couple radiation into the sensors. The manufacturing costs of such an antenna-coupled IR FPA would be much less than integration of spectral or polarization filters onto each pixel, or fabrication of adjacent pixels with materials of different bandgaps. The antenna-coupled pixels can be made smaller than usual pixels, allowing this diversity of spectral or polarization information on the FPA without losing spatial resolution. The infrared (IR) sensors can be tunnel diodes, schottky diodes, photovoltaics, photoconductors, bolometers, and pyroelectrics. Application areas can include military and civilian remote sensing, automotive driving aids, industrial sensing, medical imaging, and general surveillance.

In a hybrid-type polarizer having a reflective-type polarizing filter and a color filter, a method of manufacturing the hybrid-type polarizer and a display device having the hybrid-type polarizer, the hybrid-type polarizer includes a base member and a polarizing color filter member. The polarizing color filter member includes a plurality of metal gratings in a plurality of regions of the base member. The metal gratings in the regions have different sizes from each other. Each of the metal gratings transmits a first portion of an incident light and reflects a second portion of the incident light. The invention improves image display quality and lowers the manufacturing cost.

A polarimetric imaging system employs a pixel pitch matched filter for use within, for example, a 2 by 2 pixel neighborhood, in which one pixel samples the scene via a 0 degree polarization filter and a second pixel samples the scene via a 45 degree polarization filter. The remaining two pixels record the intensity of the light within the 2 by 2 neighborhoods. The polarization filters employ organic materials such as polymers or metallic materials that are patterned and etched using reactive ion etching (RIE) or other appropriate etching technique in order to create 14 micron or smaller circular (or square) periodic structures that are patterned into polarization thin films that are deposited on an imaging sensor that includes a processor that computes from the polarization-filtered inputs the first three Stokes parameters in real-time.

The present invention discloses a stereoscopic display employing polarized eyewear. The basic component of the present invention stereoscopic display is a stereopolarizer, which is a polarized screen comprising microscopic sections of mutually extinguishing polarizing filters dispersed throughout the screen. To achieve the proper resolution, the size of the microscopic polarizing filter needs to be in order of micrometer, from a few microns to a few hundred of microns. The arrangement of the microscopic polarizing filters can be alternating stripes in horizontal, vertical, or any arbitrarily direction. The microscopic polarizing filters can be arranged in alternating pattern, such as alternating square or circle. The polarizer screen can be one sheet or can be a composite sheet, comprising two distinct polarizer filter sheet laminated together. Laser drilling is used to fabricate the microscopic polarizing filters, primarily due to ease of operation and appropriate microscopic sizes. Further, laser drilling and cutting can form angle holes in the stereopolarizer, which provides optimum focus viewing for horizontal perspective display.

A detector (110) for determining a position of at least one object is proposed. The detector (110) comprises: —at least one angle dependent optical element (130) adapted to generate at least one light beam (131) having at least one beam profile depending on an angle of incidence of an incident light beam (116) propagating from the object (112) towards the detector (110) and illuminating the angle dependent optical element (130), wherein the angle dependent optical element (130) comprises at least one optical element selected from the group consisting of: at least one optical fiber, in particular at least one multifurcated optical fiber, in particular at least one bifurcated optical fiber; at least one diffractive optical element; at least one angle dependent reflective element, at least one diffractive grating element, in particular a blaze grating element; at least one aperture stop; at least one prism; at least one lens; at least one lens array, in particular at least one microlens array; at least one optical filter; at least one polarization filter; at least one bandpass filter; at least one liquid crystal filter, in particular a liquid crystal tunable filter; at least one short-pass filter; at least one long-pass filter; at least one notch filter; at least one interference filter; at least one transmission grating; at least one nonlinear optical element, in particular one birfringent optical element; —at least two optical sensors (113), wherein each optical sensor (113) has at least one light sensitive area (121), wherein each optical sensor (113) is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area by the light beam (131) generated by the angle dependent optical element (130); at least one evaluation device (133) being configured for determining at least one longitudinal coordinate z of the object (112) by evaluating a combined signal Q from the sensor signals.

The invention relates to a method, in which from two images of a security element, which are recorded with right-handed and left-handed circularly polarizing filters, a differential image is produced, on the basis of which the authenticity of the security element is tested, and an apparatus for carrying out the method.

A stereoscopic display and record component, more specifically a dual polarizing light filter, and the methods of applying the component for stereoscopic image displaying and stereoscopic image recording, are disclosed. A dual polarizing light filter may be statically or dynamically controlled to deliver or accept polarizing light of different orientations at different micro regions on the filter at different times. The invention may be used to create a new type display device and a new type of recording method for both 2-D and 3-D images. The component may be added to existing displays as well as integrated into the display fabrication process.

A four-panel liquid-crystal-on-silicon (LCOS) projection display system utilizes four available ports of a beam splitter and polarization filter architecture to provide a four-color component image with an increased brightness and color gamut compared with typical three-color component images. The projection display system includes a light source, four light modulating panels, a light directing subsystem, and a projection lens. The light source is operable to generate light having four color components. Each of the four light modulators is operable to generate a respective image associated with the respective one of the four color components. The light directing subsystem is operable to split the four color components before modulation and recombine them after modulation, and each light modulator is located at a separate port of the light directing subsystem. The projection lens is operable to project an image of the modulated combined color components.

According to the present invention, there are provided a polarization filter and a sensor system. The polarization filter includes a circularly polarized light-separating layer having a cholesteric liquid crystalline phase fixed therein, in which the circularly polarized light-separating layer is a layer which selectively transmits one of the left-hand circularly polarized light and the right-hand circularly polarized light in the specific wavelength band, a λ/4 phase difference layer for light in the specific wavelength band is disposed on one of the surfaces of the circularly polarized light-separating layer, and the λ/4 phase difference layer includes a first phase difference region and a second phase difference region of which slow axis directions are orthogonal to each other. The sensor system includes the polarization filter, a light source which emits light having a wavelength in the specific wavelength band, and a light-receiving element which can detect light having a wavelength in the specific wavelength band. The polarization filter of the present invention can improve the sensitivity of a sensor system using polarized light, and the sensor system of the present invention has high sensitivity and is extremely cost effective.

An encoder having a code scale and an emitter detector module is disclosed. The code scale includes alternating reflective and opaque stripes. The emitter-detector module includes a light source that generates light and directs a portion of the generated light to the imaging element and a photodetector that generates a signal representing an intensity of light having a linear polarization in a predetermined direction received by the photodetector, the light source and the photodetector are encapsulated in a transparent medium, wherein there is a gap between the transparent medium and the code scale. The predetermined direction is chosen to reduce the intensity of light received by the photodetector that is reflected from an interface between the transparent medium and the gap. A polarization filter can also be included in the light source to further improve the rejection of the light reflected from the interface of the transparent medium and the gap.

The invention relates to an organic compound taking triazine and benzimidazole as cores and application thereof to an OLED (Organic Light Emitting Diode) device. The compound provided by the invention has relatively high glass transition temperature and molecule thermal stability; the compound has low absorption and high refractive index in the field of visible light; after the compound is applied to a CPL (Circular Polarizing Filter) layer of an OLED device, the light extraction efficiency of the OLED device can be effectively improved; the compound also has a deep HOMO energy level and high electron mobility and can be used as a hole-blocking/electron transferring layer material of the OLED device; and the compound can be used for effectively stopping a hole or energy from being transmitted to one side of an electron layer from a light emitting layer, so that the compounding efficiency of the hole and electrons on the light emitting layer is improved, and furthermore, the luminous efficiency of the OLED device is improved and the service life of the OLED device is prolonged.

A method for demonstrating pre-emergent pimples is disclosed. The method includes providing a camera having a 25 mm macro lens and a linear polarizing filter including from 10 to 50 narrow band filters in the spectral range of 400-970 nm, and a light source having a linear polarizer oriented vertical to a polarization plane of the camera polarizer; taking a sequence of images of the face of a subject with the camera; creating an erythema map of the imaged area using oxy-hemoglobin values at each corresponding pixel; taking a visible-light image of the face of the subject; and comparing the images to see pre-emergent pimples. The method enables consumers to see pre-emergent pimples and treat them, which results in preventing the pimples from emerging or reducing the emergence of the pimples.

Image measurement values of a measurement object, in particular a printed sheet, measured by means of a photoelectric image measuring unit operating on the basis of pixels are corrected with respect to at least one influencing variable which influences the measurement result with a view to at least partially eliminating the effect of this influencing variable on the measuring process. The image measurement values measured by the image measuring unit are converted by correction parameters of a parameter-based correction model into corrected image measurement values which no longer contain the influencing variable affecting the measuring process. The correction parameters used for the parameter-based correction model are automatically calculated using reference measurement values measured at reference measurements points on preferably the same measurement object by means of a reference measuring unit and the image measuring unit. In particular, image measurement values measured without polarization filters are converted into polarization filter image measurement values by means of this method. Influences induced by print medium, fluorescence effects and the influences of non-standard measuring geometries are also corrected.

A polishing end point detection method is to detect a polishing end point of a workpiece having a multilayer structure. The method is performed by emitting a first light and a second light to a surface of the workpiece at a first angle of incidence and a second angle of incidence, respectively, receiving the first light and the second light reflected from the surface through a polarizing filter, performing a first analyzing process of analyzing a brightness and a saturation of the surface from the first light received, performing a second analyzing process of analyzing a brightness and a saturation of the surface from the second light received, and determining removal of the upper layer based on changes in the brightness and the saturation of the surface.

The invention relates to a device (20) and a method for making visible security elements present in an object (4) and comprising at least one photoluminescent segment which is characterized by linearly polarized photoluminescence and/or linearly polarized absorption. According to the invention, a good contrast is achieved with few interfering signals, by arranging at least one light source (1) and at least one polarization filter (2) in such a way that the light (24) from the light source (1) is linearly polarized (23) by means of the polarization filter (2) and hits the object (4) or the photoluminescent segments in said object, and photoluminescent light (25) from the segments can be observed through another and/or the same polarization filter (2).

This invention relates to the non-invasive determination of the degree of vasoactivity in the microcirculation in a tissue caused by a drug, disease, injury normal or pathological regulation. More specifically, the invention relates to a method of determining the influence on microcirculation in living tissue from an irritative agent, drugs, disease, injuries normal or pathological regulation including, illuminating a tissue surface with polarized light, collecting the backscattered light through a polarizing filter, detecting the backscattered and polarized light by a photo-sensitive array, transferring the collected information in digital form to a computing device, separating the collected information into at least two data matrixes, each representing a specific wavelength range and generating an output data matrix by processing corresponding values in at least two data matrixes by an algorithm, wherein each value in said output data matrix represents the amount of influence on the microcirculation in a source point of the tissue. Thereby a representation of the tissue microcirculation is obtained.

According to the invention, there is provided a circular polarizing filter for selectively transmitting circularly polarized light of any one sense of either right-handed circularly polarized light or left-handed circularly polarized light at a specific wavelength in which scattering transmittance/vertical transmittance when circularly polarized light of the sense of the specific wavelength enters from any one surface is less than scattering reflectance/regular reflectance when circularly polarized light of the other sense enters from the surface. The circular polarizing filter includes a circularly-polarized light separating layer, the circularly-polarized light separating layer includes a reflected light-scattering circularly-polarized light separating layer, and may further include a reflected light-non-scattering circularly-polarized light separating layer, the reflected light-scattering circularly-polarized light separating layer is composed of a layer having a cholesteric liquid crystalline phase fixed therein, and the reflected light-non-scattering circularly-polarized light separating layer is composed of a layer having a cholesteric liquid crystalline phase fixed therein, or a laminate including a linearly-polarized light separating layer and a λ/4 phase difference layer. The circular polarizing filter of the invention has a high circular polarizance, and a high-sensitivity sensor system can be provided using the circular polarizing filter of the invention.

An image sensor includes a pixel array, a micro lens array and polarizing filters. The pixel array includes a plurality of pixels. The micro lens array is disposed on the pixel array and includes a plurality of micro lenses. The micro lens overlaps a pixel group of the pixel array. The polarizing filter is disposed on the micro lens and includes a plurality of polarizing filters having at least two different polarizing phases. Accordingly, the accuracy and the reliability of the local auto white balancing may be improved.