99 results about "Off-axis illumination" patented technology

A system and method for eye gaze tracking in human or animal subjects without calibration of cameras, specific measurements of eye geometries or the tracking of a cursor image on a screen by the subject through a known trajectory. The preferred embodiment includes one uncalibrated camera for acquiring video images of the subject's eye(s) and optionally having an on-axis illuminator, and a surface, object, or visual scene with embedded off-axis illuminator markers. The off-axis markers are reflected on the corneal surface of the subject's eyes as glints. The glints indicate the distance between the point of gaze in the surface, object, or visual scene and the corresponding marker on the surface, object, or visual scene. The marker that causes a glint to appear in the center of the subject's pupil is determined to be located on the line of regard of the subject's eye, and to intersect with the point of gaze. Point of gaze on the surface, object, or visual scene is calculated as follows. First, by determining which marker glints, as provided by the corneal reflections of the markers, are closest to the center of the pupil in either or both of the subject's eyes. This subset of glints forms a region of interest (ROI). Second, by determining the gaze vector (relative angular or Cartesian distance to the pupil center) for each of the glints in the ROI. Third, by relating each glint in the ROI to the location or identification (ID) of a corresponding marker on the surface, object, or visual scene observed by the eyes. Fourth, by interpolating the known locations of each these markers on the surface, object, or visual scene, according to the relative angular distance of their corresponding glints to the pupil center.

Certain embodiments include a head mounted display for displaying images that can be viewed by a wearer when the display is worn on the wearer's head. The display can include a spatial light modulator having an array of pixels selectively adjustable for producing spatial patterns. The array of pixels can define a substantially planar reflective surface on the spatial light modulator. The display can further include a light source. The display can also include illumination optics disposed to receive light from the light source and direct light onto the planar reflective surface of the spatial light modulator at an angle with respect to the surface normal of the planar reflective surface. The display can include imaging optics disposed with respect to the spatial light modulator to receive light from the spatial light modulator. The display can further include a curved reflector disposed to reflect light from the imaging optics so as to form a virtual image such that the image may be viewed by an eye of the wearer. The display can also include headgear for supporting the spatial light modulator, imaging optics, and reflector. In certain embodiments, only rays of light incident on the planar reflective surface of the spatial light modulator at an angle with respect to the surface normal of the planar reflective surface contribute to the virtual image viewable by the eye.

A system and method for fundus imaging wherein selective illumination of a sector of the field of view of the fundus, using off-axis illumination, provides images of acceptable clarity, resolution, and size, with significantly reduced reflections, in a compact system. By rotating illumination around the optical axis, sectors of the fundus may be selectively and sequentially illuminated. An image of the entire field of view of the fundus is obtained by combining images, e.g. two or more half images, obtained within a single shutter exposure or capture period. An illumination system using LED light sources and a rotatable occluder provides for a lightweight, handheld and portable fundus imaging system. It may take the form of a fundus camera, a fundus imaging lens module for regular camera, or an adapter which couples to the standard lens of a camera to create a low cost fundus camera.

An optical hyperspectral/multimodal imaging method and apparatus is utilized to provide high signal sensitivity for implementation of various optical imaging approaches. Such a system utilizes long working distance microscope objectives so as to enable off-axis illumination of predetermined tissue thereby allowing for excitation at any optical wavelength, simplifies design, reduces required optical elements , significantly reduces spectral noise from the optical elements and allows for fast image acquisition enabling high quality imaging in-vivo. Such a technology provides a means of detecting disease at the single cell level such as cancer, precancer, ischemic, traumatic or other type of injury, infection, or other diseases or conditions causing alterations in cells and tissue micro structures.

Improvements in the fabrication of integrated circuits are driven by the decrease of the size of the features printed on the wafers. Current lithography techniques limits have been extended through the use of phase-shifting masks, off-axis illumination, and proximity effect correction. More recently, liquid immersion lithography has been proposed as a way to extend even further the limits of optical lithography. This invention described a methodology based on contact or proximity printing using a projection lens to define the image of the mask onto the wafer. As the imaging is performed in a solid material, larger refractive indices can be obtained and the resolution of the imaging system can be increased.

A stencil printer is provided for depositing solder paste onto a surface of an electronic substrate. The stencil printer includes a frame and a stencil coupled to the frame. The stencil has a plurality of apertures formed therein. The stencil printer further includes a dispenser coupled to the frame. The stencil and the dispenser are adapted to deposit solder paste onto the electronic substrate. The stencil printer further includes an imaging system constructed and arranged to capture an image of the electronic substrate. The imaging system includes a camera assembly, an on-axis illumination assembly adapted to generate light substantially along a first axis generally perpendicular to the surface of the electronic substrate, and an off-axis illumination assembly adapted to generate rays of light substantially along a second axis extending at an angle with respect to the first axis. A controller is coupled to the imaging system to control movement of the imaging system to capture an image.

A method for fabricating a a semiconductor device that includes: providing a substrate prepared with a photoresist layer; providing a photomask comprising a first and a second pattern having a respective first and second pitch range; providing a composite aperture comprising a first and a second off-axis illumination aperture pattern, the first off-axis aperture pattern having a configuration that improves the process window of the first pitch range and the second off-axis aperture pattern having a configuration that improves the process window for a second pitch range; exposing the photoresist layer on the substrate with radiation from an exposure source through the composite aperture and the photomask; and developing the photoresist layer to pattern the photoresist layer.

The invention discloses a high-magnification three-dimensional imaging microscope based on double-light source off-axis illumination and an imaging method and relates to a device for acquiring a left path of image and a right path of image by a CCD (Charge Coupled Device), a method for changing focus depth, a method for acquiring and separating two paths of images, a system calibrating method and a three-dimensional coordinate calculating method of a target. The three-dimensional imaging microscope mainly comprises a left off-axis light source, a right off-axis light source, a concentrated projecting assembly, a microobjective and a CCD, wherein the left off-axis light source and the right off-axis light source are symmetrical. The imaging method comprises the following steps of: calibrating the relation of microscope defocusing amount and double-image distance; acquiring an image; processing the image; recognizing a target; calculating a two-dimensional coordinate; and converting the two-dimensional coordinate into a three-dimensional coordinate. A left and right image synchronous acquiring method comprises a two-color method and a polarization method, and an asynchronous acquiring method comprises an LED switching illumination method. The three-dimensional coordinate of an object can be rapidly calculated. An illuminating light beam is converged on entrance pupils of the microobjective, the diameter of the light beam is limited by a variable diaphragm, and the focus depth is changed, thereby maintaining the illumination of the image surface to be basic invariant.

Systems and methods are described for content-based fused off-axis illumination direct-to-digital holography. A method includes calculating an illumination angle with respect to an optical axis defined by a focusing lens as a function of data representing a Fourier analyzed spatially heterodyne hologram; recording a content based spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; Fourier analyzing the recorded content based spatially heterodyne hologram including spatially heterodyne fringes by transforming axes of the recorded content based spatially heterodyne hologram including spatially heterodyne fringes in Fourier space to sit on top of a heterodyne carrier frequency defined as an angle between the reference beam and the object beam; applying a digital filter to cut off signals around an original origin; and then performing an inverse Fourier transform.

The invention discloses a photolithography exposure device for implementing off-axis illumination by using a free-form surface lens. The photolithography exposure device comprises a laser source, a beam expander, a free-form surface lens beam shaper, a filtering diaphragm, a varifocal optical system, an optical integrator, a collimation optical system, a field diaphragm, a relay optical system, a mask, a photolithography projection objective and photoresist, wherein the relay optical system comprises a front lens group, a middle reflection lens and a rear lens group; the position of the filtering diaphragm and the position of the front surface of the optical integrator form a pair of conjugate positions of the varifocal optical system; the position of the rear surface of the optical integrator and the position of the field diaphragm form a pair of conjugate positions of the collimation optical system; the position of the field diaphragm and the position of the mask form a pair of conjugate positions of the relay optical system; and the position of the mask and the position of the photoresist form a pair of conjugate positions of the photolithography projection objective. The photolithography exposure device has the advantages of good shaping effect and high energy utilization rate.

Systems and methods are described for rapid acquisition of fused off-axis illumination direct-to-digital holography. A method of recording a plurality of off-axis illuminated spatially heterodyne holograms, each of the off-axis illuminated spatially heterodyne holograms including spatially heterodyne fringes for Fourier analysis, includes digitally recording, with a first illumination source of an interferometer, a first off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; and digitally recording, with a second illumination source of the interferometer, a second off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis.

The present invention provides a halftone mask comprising an assist pattern and a manufacturing method of the halftone mask, which uses an ArF excimer laser as an exposing source, is used for a projection exposure by an off axis illumination, does not resolve the assist pattern while keeping the focal depth magnification effect as the assist pattern, and may form a transferred image having high contrast of a main pattern. A photomask is a photomask comprising the main pattern which is transferred to a transfer-target surface by the projection exposure and the assist pattern which is formed nearby the main pattern and not transferred, characterized in that the main pattern and the assist pattern are each constituted from a semi-transparent film made of the same material, a retardation of 180° is generated between the light transmitting through the main pattern and the light transmitting through a transparent region of a transparent substrate, and a predetermined retardation within the scope of 70° to 115° is generated between the light transmitting through the assist pattern and the light transmitting through the transparent region of the transparent substrate.

The present invention relates to a fixing apparatus for ball lens used for facilitating installation of concentrator solar cell receiver module. The present invention can finish installing the fixing base for ball lens at a time and positioning the ball lens rapidly and accurately. It can also control the distance between the ball lens and the solar cell excellently. In addition, the present invention further has the function of sheltering the circuit of concentrator solar cell receiver module. When off-axis illumination of sunlight occurs, direct illumination of sunlight on, and consequently high-temperature burnout of, the circuit can be avoided. Thereby, the lifetime of the circuit can be extended effectively and the probability of failure can be reduced as well.

The present invention describes an aperture comprising an opaque plate with a central opening and at least one peripheral opening and a method for combining an on-axis component and at least one off-axis component of illumination light.

A photomask that is capable of implementing off-axis illumination (OAI), and a method of fabricating the same, are provided. The photomask includes a transparent substrate, a plurality of opaque patterns formed on the front surface of the transparent substrate, for defining a floodlighting portion for forming patterns, and a plurality of phase gratings formed on the back surface of the transparent substrate, allowing off-axis illumination (OAI) of an incident light source beyond the OAI limit of exposure equipment, allowing use in the outmost region of an aperture, and allowing modified illumination having a shape suitable for the layout of the opaque patterns.

Inspection of partially drilled microvias by fluorescence based optical imaging techniques, selective coaxial illumination and multivariable off-axis illumination and the use of comparative image analysis and the transformation of back reflected radiation by means of an integrated fluorescing plate mounted to the surface of a CCD or EMCCD array.