92 results about "Ocular straylight" patented technology

The present invention provides an optical system for illuminating and viewing a target in which an illumination element and a receiving means are disposed behind a single optical window, and which obtains data essentially free of backscatter and stray light. The optical window of the optical system is configured such that it defines a shape having at least one focal curve, i.e., an ellipsoid shaped dome. The illumination element and the receiving means are geometrically positioned on the focal curve plane or in proximity of the focal curve plane, such that, when illuminating, rays from the illumination elements, that are internally reflected from the optical window, will not be incident on the receiving means.

A polarization beam splitter selectively decouples detection light onto a detector such that it has a polarization direction that differs from the emitted illumination light. This enables the detection of the light scattered back in the eye lens at a high level of accuracy, since stray light from reflections at optical components of the light path is suppressed. In the generating of photo disruptions or other incisions, the ray exposure of the retina may be reduced in that the incisions being furthest away from the laser are induced first such that laminar gas inclusions with an existence duration time of at least 5 seconds result. In this manner the laser radiation propagated in the direction of the retina in further incisions are scattered and partially reflected such that the influence impinging upon the retina is reduced.

The invention relates to a near-to-eye display type optical system based on a curved surface microlens array, wherein comprises a flexible OLED (organic light emitting diode) display element, and a microlens array manufactured on a curved surface, wherein the curved surface of the OLED and the curved surface of the microlens array are concentric spherical surfaces, the semi-diameter of the curved surface of the OLED is slightly greater, the positions of pixel units of the OLED on the spherical surface are corresponding to the positions of the microlens array one by one, the centers of the OLED and the microlens array are on the same semi-diameter after the assembling. By adopting the microlens array, the weight and the volume of an optical imaging part of the near-to-eye display optical system are obviously decreased, the whole system can be lightened and miniaturized; the microlens array closes to the OLED display unit, so that the light energy utilization rate is increased, the image brightness is increased and the influence of stray light is decreased.

This invention relates to an in-situ test method for stray light in a step scan projection aligner, which limits a spot on an object face by accurately positioning four slit blades and images on a working platform by a projecting object lens. An energy sensor tests that the light intensity at the spot photo center is Lo and finishes testing to MXN spots then to open the slit, the light intensity of above mentioned point light intensity is measured to be l, the stray light coefficient is computed by formula (1, -10)/10, if the stray light exceeds the required target of the exposure system, it analyses source of stray light. A special mask and two slit blades limit a spot imaged by projection object lens, an energy sensor tests light intensity distribution in the image spot to analyze if the stray light is from the illumination system or the project object lens.

Presbyopic contact lenses that provide improved vision quality by use of optical zones which are not symmetric about the lens optical axis. The contact lens includes an optic body sized and configured to be received in an eye (or eyes) of a presbyopic patient having a front surface with a front optical center and a back surface with a back optical center, and having a lens optical axis intersecting the front surface at the front optical center and the back surface at the back optical center, and having optical zones which are not symmetric about the lens optical axis. The lens construction produces an asymmetric point spread function which enables any resulting asymmetric stray light to be steered in a predetermined direction.

An adaptive-optics OCT retina imager using a coherence-gated wavefront sensor comprises a light source, a polarizer, a first broadband polarization light splitting prism, a second broadband polarization light splitting prism, a first lambda/4 wave plate, a second lambda/4 wave plate, a first broadband light splitting plate, a second broadband light splitting plate, a deformation mirror, a two-dimensional scanner, a microlens array, a first polarization analyzer, a second polarization analyzer, a wavefront detector, a reference mirror, an imaging detection module, a data acquisition card, a computer, a function generation card, a high-voltage amplifier and the like. By adopting the coherence-gated wavefront sensing technology, the adaptive-optics OCT retina imager collects and corrects wavefront aberrations of an imaged layer in a retina and therefore filters wavefront aberrations produced by other layers and devices in an optical path, and transverse resolution close to the diffraction limit is obtained; besides, the Fourier domain OCT technology comprising spectral domain OCT and sweep frequency OCT is adopted for conducting high-resolution longitudinal tomography of the retina. The adaptive-optics OCT retina imager has the advantages that wavefront detection is insensitive to stray light, the strength of wavefront detection signals can be enhanced, and the external dimension of the adaptive-optics OCT retina imager is reduced.

An imaging optical system a high quality image may be implemented by determining the optimum design conditions for suppressing the generation of ghost while holding uniform and sufficient light using a simulation method. In the imaging optical system having a slit, the requirements for removing the stray light are the inclination of a lens arrangement direction, the slit width, the lens pitch, the view angle, and the height of the light-shielding wall. The slit location, the lens thickness, and the lens row width do not affect the stray light removal, but affect the brightness. In the imaging optical system having no slit, the essential requirements for removing the stray light are the height of the light-shielding wall and the lens pitch. The lens thickness and the lens row width do not affect the stray light removal, but affect the brightness.

The sensor comprises a detector (103) and a primary objective (105) arranged in front of the detector to form on said detector images of stars present in the field of view of the sensor. Between the objective (105) and the detector (103) is arranged a field stop (107) positioned substantially in the focal plane (P) of the objective (105). Between the field stop (107) and the detector (103) is arranged a relay optics (111) for conveying an image from the focal plane of the objective to the detector.

The invention, which belongs to the technical field of stray light elimination, relates to a high-precision diaphragm slit for eliminating converging light and stray light, thereby solving problems existing in the existing stray light elimination technology. A technical scheme of the high-precision diaphragm slit is characterized in that the diaphragm slit comprises a hollow cylindrical housing and grille barriers that are arranged inside the hollow cylindrical housing. The grille barriers include a set of barrier sheets; each of the barrier sheets has a central hole; and the central hole of the central barrier sheet is used as a symmetrical center and apertures of the central holes of the barrier sheets at the two sides are gradually reduced to form a biconical incident cavity. The hollow cylindrical housing and all the barrier sheets are coaxially arranged; and diffuse reflection blackening materials with stable performances are sprayed at surfaces of the hollow cylindrical housing and all the barrier sheets. According to the invention, the provided high-precision diaphragm slit can be especially used for eliminating stray lights in a spatial optical remote sensing instrument.

A lens includes first and second opposing surfaces extending radially from an optical axis in an optical system for passing light received from an object. The lens includes a peripheral edge extending between the first and second surfaces. A portion of the peripheral edge has at least either a positive slope or a negative slope with respect to the optical axis. The positive or negative slope of the peripheral edge is configured to reduce glare from stray light received from the first surface. A portion of the peripheral edge may be shaped in a sawtooth pattern or an approximate sinusoidal pattern. The peripheral edge of the lens is also configured to direct light that is received from the object toward light traps which are disposed adjacent to the lens.

The invention discloses a method and a device for correcting stray light of a spectrograph. A plurality of color filters capable of being cut in are arranged on a light path between a light signal entering slit and a color dispersion element of the spectrograph, the same light source to be measured is respectively measured when each color filter is cut in and when light filters are not cut in, stray light distributing factors are calculated by the measured spectrum, the stray light error of the light source to be measured or other light sources is corrected and measured by using the stray light distributing factors, and the color filters can also be combined with laser to further correct the stray light; or the color filters and the laser are combined to correct the stray light generated by light radiation outside the measuring waveband of the spectrograph, and the stray light in the measuring waveband of the spectrograph is corrected by using the laser; and the corresponding measurement and control software of the spectrograph comprises a stray light correction program capable of conveniently and rapidly realizing the correction of the stray light. The invention can realize the correction of the stray light in the measuring waveband of the spectrograph and the stray light caused by the light radiation outside the measuring waveband and has convenient operation and is easy to realize high-precision spectral measurement.

An annular lighting device for an eye ground camera relates to the field of medical optics, and solves the problems that the utilization rate of lighting system energy is low, retina lighting is not uniform, and annular diaphragm with high cost is used in the conventional eye ground camera. A lighting source sent out by a light source generates uniform annular faculae after passing through a lighting optical system; the uniform annular faculae light cornea edge areas of people, and can keep away from cornea central areas capable of strongly reflecting light, so that the uniformity of eye ground lighting is improved; further, the width of annular light beams can be changed through adjusting the distance between a positive axial conical mirror and a negative axial conical mirror in a lighting light path to be adapted to different eyes of people; and real images are formed in the middle of the system for two times, the influence of stray light such as cornea reflected light on the imaging quality is greatly reduced through adding confocal filtering apertures and adopting a reflecting mirror foldable light path.

The disclosed device comprises three pieces of parallel placed convex lenses with coincided centerlines, a beam splitting plate, a plane reflector and a Bragg acousto-optic modulator. Received by lens 1 and passing through lens 2, an inquire light becomes a narrow beam. Then, passing through the beam splitting plate, the beam is divided into a transmission light and a reflection light. The transmission light is a receiving signal. Reflected by the plane reflector, the reflection light forms an echo light beam and passing through the Bragg acousto-optic modulator to return in direction parallel to the inquire light. Diaphragm and light filter can be added to the device to filter the inquire light in space and frequency in order to raise detection SNR at response party. Features are: small loss of luminous energy, simple structure, and small size. Moreover, the invention increases communication and identification distances, and possesses better modulation effect.

The invention discloses an internally occulting type imaging system of a transmission occulting coronagraph, and aims to solve the problem that stray light is difficult to restrain in the prior art. The system comprises an incident aperture diaphragm, an objective lens, an internally occulting body, a field lens, an Lyot diaphragm, an Lyot spot and a relay lens group which are mounted on an optical axis in a lens cone according to a sequential order after sunlight enters the lens cone, wherein the incident aperture diaphragm is located in the first surface position of the objective lens; the internally occulting body is located in the imaging focal plane position of the objective lens; the Lyot diaphragm is located in the imaging focal plane position, where the incident aperture diaphragm passes through, of the objective lens; the Lyot spot is located in the imaging focal plane position of the field lens; and after sunlight beams are focused by the objective lens, sunlight on a solar photosphere layer is shaded by the internally occulting body, and the obtained light beams are imaged on an image plane CCD (charge coupled device) through the field lens and the relay lens group. The internally occulting type imaging system of the transmission ground-based coronagraph is provided with the internally occulting body and the Lyot spot, ghost images can be effectively blocked, and the stray light restraining capacity of the transmission ground-based coronagraph is further improved, therefore, the system can be used for observing sun corona.

The invention relates to a Hartmann wave-front sensor eliminating astigmatism of system itself, comprising measuring light source system, beam matching system, micro-lens array and CCD. Polarizer is set at the front of light outlet of measuring light source system and 1/4 wave plate is set between beam matching system and measured part. Polaroid analyzer is set at the front of micro-lens array and the polarizing detecting direction of Polaroid analyzer is vertical with the polarizing direction of polarizer. Light emitted by the measuring light source system becomes linear polarized light by the polarizer and after the linear polarized light passes through the beam matching system it becomes circular polarized light. After it passes trough measured part it returns system. After 1/4 wave plate circular polarized light becomes linear circular polarized light. Here polarized direction is vertical with the polarized direction when it is emitted by polarizer. After beam matching system and Polaroid analyzer, it enters into micro-lens array to measure. The invention decreases centroid calculation error generated by stray light and improves measuring accuracy.

The invention discloses a fundus camera with a coaxial lighting source and fixation light source. The fundus camera comprises a machine body optical assembly, an ophthalmoscope optical assembly and eyes, wherein the machine body optical assembly comprises a photosensitive element and a fixation lamp assembly, the photosensitive element is used for acquiring an image of the fundus, the fixation lamp assembly is used for guiding a tested person for fundus imaging, the fixation lamp assembly comprises a central fixation lamp light emitting unit and an edge fixation lamp light emitting unit, the ophthalmoscope optical assembly comprises a first lens group, a second lens group, a third lens group, an incident polarizer, a beam splitter, an emergent polarizer and a lighting source assembly. Thefundus camera with the coaxial lighting source and fixation light source has the advantages that it is avoided that stray light generated by the lighting source enters a subsequent imaging optical path to the photosensitive element, it is also avoided that stray light generated by the fixation light source enters the subsequent imaging optical path to the photosensitive element, and only diffuse reflection light depolarized in a fundus area can pass through the emergent polarizer.

The invention discloses a system and a method for eliminating stray light of satellite images. The system comprises a data acquisition module, an image registration module and a stray light suppression module; the data acquisition module comprises an image grayscale acquisition unit and an image parameter acquisition unit, the image registration module comprises an image rough registration unit and an image fine registration unit, and the stray light suppression module comprises a proportion coefficient computation unit, a difference image computation unit and an image filter unit. The system and the method have the advantages that high-definition camera images and wide camera images which are simultaneously formed in orbits are registered at first, corresponding relation models of grayscale values of the high-definition camera images and grayscale values of the wide camera images are built according to spectral corresponding relations among the images, accordingly, influence of the stray light in the images can be eliminated, the method for eliminating the stray light of the images is simple and practical, real information of the images can be preserved to the great extent, and a good stray light eliminating effect can be realized.

The invention discloses a device and method for testing the out-band relative spectral responsivity of a solar blind ultraviolet image intensifier, and relates to the technical field of parameter testing of the solar blind ultraviolet image intensifier. The problem that the relative spectral responsivity of a solar blind ultraviolet image intensifier cannot be accurately tested due to the extremely low out-band response is solved. The device comprises a light source, a dark box, a telescopic shielding case, a trap detector, a shielding box and an electrometer. The dark box is placed in front of the light source, and a light inlet is formed in the side face of the dark box. The telescopic shielding case is placed between the light inlet and the light source and is used for shielding the environment stray light nearby the light source from entering the dark box. The trap detector is placed inside the dark box and is used for detecting the output light currents of the light source. The shielding box is placed inside the dark box and is used for containing the image intensifier to be tested and for conducting effective electromagnetic shielding on the image intensifier to be tested. The electrometer is connected with the signal output end of the image intensifier and is used for detecting output electric signals passing through the image intensifier to be tested of the light source. The device for testing the out-band relative spectral responsivity of the solar blind ultraviolet image intensifier is simple in structure and high in operability.

The invention relates to an in-situ luminous flux monitoring and exposure dose compensating method. The method comprises the following steps: measuring the luminous flux of a main light beam going through an exit slit and entering a vacuum chamber before a lithography experiment by using a photodiode, monitoring the intensity of main light beam going through the exit slit and entering the vacuum chamber and the luminous flux of stray lights directly proportional to the main light beam during experimental exposure, and adjusting the exposure time of each lithographic area in real time accordingto the change of the intensity of the stray lights to compensate for the exposure dose in order to keep the exposure dose constant in the XIL large-area exposure pattern splicing process, ensure thatthe nanostructure in the finally obtained large-area exposure pattern is uniform and effectively improve the performances of a device formed by the exposure pattern.