897 results about "Entrance pupil" patented technology

A see-through head-mounted optical apparatus for a viewer has at least one display module, each display module having a display energizable to form an image and a positive field lens optically coupled to the surface of the display and disposed to direct imaged light from the display toward a first surface of a prism. A curved reflector element is in the path of the imaged light through the prism and disposed at a second surface of the prism, opposite the first surface. The curved reflector element has a refractive surface and a curved reflective surface disposed to collimate imaged light received from the display and direct this light toward a beam splitter that is disposed within the prism and that is at an oblique angle to the collimated reflected light. The beam splitter redirects the incident collimated reflected light through the prism to form an entrance pupil for the viewer.

Image display device having an image source generating an image, a beam splitter positioned at forty five degrees to the main optical path, to project and focus the image generated by the image source into the entrance pupil of the human eye, two achromatic standard doublet lenses positioned perpendicularly to the main optical path and placed between the image source and the beam splitter, and configured to amplify, collimate, and correct optical aberrations of said image, wherein the image source, beam splitter and the doublet lenses are in an on-axis configuration and the image display device comprises two mounting brackets parallel to the main optical axis, each having an extremity part holding an edge of the beam splitter and the other extremity pivotally attached to a housing, allowing the brackets and beam splitter to rotate in an axis perpendicular to the main optical path.

The invention discloses a satellite-borne remote sensor radiation calibration method based on atmospheric parameter remote sensing retrieval. The method includes nine steps. A surface reflectance is obtained through ground synchronous actual measurement during satellite crossing or historical data, imaging time and observation geometry parameters are obtained through remote sensing data head files, atmospheric parameters during imaging of synchronous crossing meteorological satellite sensors or related load retrieval remote sensors are utilized, the entrance pupil radiance of the remote sensors is calculated by an atmospheric radiation transmission model according to retrieval results of the atmospheric parameters, a calibration coefficient is calculated through a radiation calibration model, and thereby the on-orbit radiation calibration for a satellite-borne remote sensor is achieved. The satellite-borne remote sensor radiation calibration method based on the atmospheric parameter remote sensing retrieval is a pixel-level calibration method and has the advantages that the accuracy is high, the costs are low, simultaneously, the high frequency calibration can be achieved, historical remote sensing data can be calibrated, and the method has a wide application prospect to remote sensing data processing methods and application technical fields.

The invention relates to a camera lens. The camera lens has the total effective focal length f and entrance pupil diameter EPD, and the camera lens sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens from the object side to the image side along the optical axis. The first lens has positive power, and the object side face of the first lens is a convex face; the second lens has positive power, and the object side face and the image side face of the second lens are convex faces; the third lens has negative power, the fourth lens and the fifth lens each have positive power or negative power, the sixth lens has positive power or negative power, and the image side face of the sixth lens is a concave face at the paraxial position; the seventh lens has negative power, and the image side face of the seventh lens is a concave face at the paraxial position, wherein the total effective focal length f and entrance pupil diameter EPD meet the formula f/EPD<=1.9.

An optical information recording device, a reproduction device, and a method enabling include a first spatial light modulator I for generating information light by spatially modulating light from a light source 143 by a plurality of pixels and a second spatial light modulator R for generating reference light by spatially modulating light from a light source by a plurality of pixels. The area I of the information light and the area R of the reference light on the entrance pupil surface of an objective lens 111 are formed such that one area surrounds the other area. The reference light is spatially modulated by the second spatial light modulator R such that interference is not easily generated between the reference lights in the information recording layer 3.

The application discloses an optical imaging lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens sequentially from the object side to the image side along an optical axis. The first lens has positive focal power, the object side of the first lens is a convex face, and the image side thereof is a concave face. The second lens has negative focal power, the object side of the second lens is a convex face, and the image side thereof is a concave face. The third lens has positive or negative focal power. The fourth lens has positive or negative focal power, and the object side of the fourth lens is a concave face. The fifth lens has positive or negative focal power. The sixth lens has positive or negative focal power. The seventh lens has negative focal power, the object side of the seventh lens is a concave face, and the image side thereof is a concave face. Total effective focal length f of the optical imaging lens and EPD (entrance pupil diameter) thereof meets f/EPD</=1.70.

The present invention concerns an imaging apparatus which works for size reductions, power savings, the efficient attainment of the quantity of light sensed, and prevention of contrast decreases due to a diffraction phenomenon, is well fit for the taking and appreciation of common still pictures, and comprises a taking lens and electronic imaging device combination that takes full advantage of the characteristics of an imaging device. The imaging apparatus comprises a taking optical system, and an electronic imaging device which is located on an image side of said taking optical system, includes an imaging plane I with a plurality of two-dimensionally arranged light sensors, and is adapted to convert an image formed through said imaging optical system into electrical signals. In at least one taking state, the apparatus satisfies at the same time condition (1) about relations of the area of the entrance pupil to the focal length of the taking optical system, condition (2) about the number of effective pixels of the imaging plane, condition (3) about the effective area of the imaging plane, and condition (4) about the division of the effective area of the imaging plane by the number of effective pixels.

The invention discloses a method and a device based on focusing and leveling of a lenticule array and belongs to the technical field of opto-electrical detection. The invention comprises an emitting part and a receiving part, wherein, the emitting part comprises a light source, a focusing lens, a pinhole filter, a beam expanding lens, an optimal entrance pupil device, a lenticule array and a steering mirror; the receiving part comprises a steering mirror, a lenticule array, a focusing lens, a scan mirror of a micro-opto-electro-mechanical-system (OMEMS), a pinhole filter and a detector. The invention adopts the optimal entrance pupil device to control light entrance quantity and then improve measuring light spot, or the quantity of the imaging point can be controlled by the state of a switch to adapt to different exposure viewing field; the invention adopts the lenticule array to replace a slit array; the scan mirror of the micro-opto-electro-mechanical-system (OMEMS) is adopted to replace the single lens scan; the difference receiving method is adopted and then the requirement for stability of the light source is decreased and higher measuring accuracy can be acquired.

An optical system includes a front end (1), a rear end image relay (2), an image transfer means (5) adapted to image the aperture stop of the rear end image relay (2) to a position where it forms the entrance pupil of the optical imaging system, and aberration correcting means (6, 7), including a lens (7) having an aspheric surface (7A) at or adjacent the aperture stop of the rear end image relay (2) and a meniscus lens (6A) to correct for both primary and higher order spherical aberration, the aspheric surface (7A) being sufficiently aspherical that chromatic error introduced by lens (7) cancels at least a major part of chromatic error introduced by the meniscus lens (6). The aberration correcting means may further include a multiple component lens (6C) to also cancel chromatic error. The front and rear ends may include one or more mirrors in different configurations.

The invention relates to a laser and middle- and long-wavelength infrared common-aperture three-band imaging system, which comprises an entrance pupil shared by each band, a primary mirror, a secondary convex mirror, a middle/long-wavelength infrared optical path imaging lens group, a laser converging light spot receiving unit, a middle- and long-wavelength infrared band beam splitter, a middle- and long-wavelength infrared dual-band imaging lens group and a detection image surface, wherein the reflection surface of the primary mirror is a concave surface, and a hole is formed in the center of the primary mirror. The system can be used for realizing the common-aperture collection of scene infrared radiation energy of the same object and laser echo energy reflected by the object; and the entrance pupil is positioned in front of the primary mirror, the secondary mirror is used for the beam splitting of laser and middle- and long-wavelength infrared bands, and a dichroic mirror is inclined to split middle-wavelength infrared light and long-wavelength infrared light, so that the system is compact in structure, the utilization rates of optical energy and space of the system are increased, the aberration correction and beam focusing of middle- and long-wavelength infrared bands are facilitated respectively, and the imaging quality is remarkably improved.

An optical coupling relay system has an imaging optical system having an object plane, an exit pupil and an image plane. An image analyzer has an image plane and an entrance pupil, and a detector is located in a detector plane and contains photosensitive material. An optical coupling relay couples the optical system to the image analyzer, for projecting the image produced by the imaging optical system into the image plane of the image analyzer and simultaneously for projecting the exit pupil of the imaging optical system into the entry pupil of the image analyzer.

The invention discloses a cross radiometric calibration method of a hyper-spectral sensor based on a multi-spectral sensor. The method is used for solving the cross radiometric calibration problem of the hyper-spectral sensor without a matched reference hyper-spectral image. The method comprises the following steps of: selecting cloudless hyper-spectral image data; selecting a multi-spectral reference image according to the hyper-spectral data; selecting a uniform ground object on the image as an interesting region; performing geometric precise correction of the two images; calculating entrance pupil radiances of various types of wave bands of the two sensors by using an atmospheric radiation transmission model; solving spectrum matching factors of various types of corresponding wave bands according to a certain rule; solving the entrance pupil radiances of the various types of wave bands of the hyper-spectral sensor by using the spectrum matching factors and the multi-spectral data; and linearly fitting pixel DN (Digital Number) values in the interesting region of the hyper-spectral image to be calibrated and the radiances of corresponding pixels of the multi-spectral reference image after being corrected through the spectrum matching factors to obtain calibration coefficients of the various types of wave bands of the hyper-spectral sensor. The method has the advantages of good stability, high reliability, high precision and the like.

An infinity display device with autostereoscopic capability having one or more high lumen light sources 6, a transmissive spatial light modulator (SLM) 7, light collimating optics and a rectilinear light guide. Once the light has passed through the SLM 7 an objective 2 converges the image encoded rays toward a point 43 representing the entrance pupil 5 of said light guide. A second lens 1 then collimates the rays in one plane (Tangential) while a lenticular array 13 is used for collimating rays in the second plane (Sagittal). Next, a first surface mirror 9 reflects all said rays toward a triangular prism 10, where they undergo colour separation before entering the light guide. The light guide may itself consist of two, parallel, first surface mirrors 3&4 one of which is partially transmissive. Finally a Fresnel screen 11 tilts the light toward the observer.

The invention discloses an optical imaging lens. The optical imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens in order from an object side to an image side along an optical axis. The first lens and the fifth lens have positive power. The second lens, the third lens and the fourth lens have positive power or negative power. The object side of the first lens and the image side of the fifth lens are convex sides. The image side of the second lens, the object side of the sixth lens and the image side of the sixth lens are concave sides. According to the total effective focal length f of the optical imaging lens and the entrance pupil diameter EPD of the optical imaging lens, f/EPD is less than or equal to 1.8.

Device (1) for projecting an image into a display area (2), with an imager (31) generating the picture, a first projection device (30) for generating a real intermediate image (R), a screen (5) onto which the first projection device (32) projects the intermediate image (R) and to a second projection device (9) projecting the intermediate image (R) into the display area (2). In order to project the image with the least possible loss of brightness, the invention provides that main beam directions (H, H′, H″) of the screen (5) point into an entrance pupil (20) of the second projection device (9).