Showing papers on "Lens (optics) published in 1999"

Projection exposure method and system

Abstract: A projection exposure method capable of keeping a liquid (7) filled between a projection optical system (PL) and a wafer (W) even while the wafer (W) is being moved when a liquid immersion method is used to conduct an exposure, wherein a discharge nozzle (21a) and inflow nozzles (23a, 23b) are disposed so as to hold a lens (4) at the tip end of the projection optical system (PL) in an X direction. When the wafer (W) is moved in a -X direction by an XY stage (10), a liquid (7) controlled to a preset temperature is supplied from a liquid supply device (5) via a supply pipe (21) and the discharge nozzle (21a) so as to fill the portion between the lens (4) and the surface of the wafer (W) and the liquid (7) is recovered from the surface of the wafer (W) by a liquid supply device (6) via a recovery pipe (23) and the inflow nozzles (23a, 23b), the supply amount and recovery amount of the liquid (7) being regulated according to a moving speed of the wafer (W).

Laterally modulated excitation microscopy: improvement of resolution by using a diffraction grating

Abstract: High spatial frequencies in the illuminating light of microscopes lead to a shift of the object spatial frequencies detectable through the objective lens. If a suitable procedure is found for evaluation of the measured data, a microscopic image with a higher resolution than under flat illumination can be obtained. A simple method for generation of a laterally modulated illumination pattern is discussed here. A specially constructed diffraction grating was inserted in the illumination beam path at the conjugate object plane (position of the adjustable aperture) and projected through the objective into the object. Microscopic beads were imaged with this method and evaluated with an algorithm based on the structure of the Fourier space. The results indicate an improvement of resolution.

Ultra-small optical probes, imaging optics, and methods for using same

Abstract: Ultra-small optical probes comprising a single-mode optical fiber and a lens which has substantially the same diameter as the optical fiber. The optical fiber and lens are positioned in a probe housing which is in the form of an insertional medical device such as a guidewire. Connector elements are provided to facilitate the attachment of the probe to an optical system and the quick disconnection of the probe from the optical system. The probe is used to obtain optical measurements in situ in the body of an organism and can be used to guide interventional procedures by a surgeon.

Imaging by parabolic refractive lenses in the hard X-ray range

Abstract: The manufacture and properties of compound refractive lenses (CRLs) for hard X-rays with parabolic profile are described. These novel lenses can be used up to ∼60 keV. A typical focal length is 1 m. They have a geometrical aperture of 1 mm and are best adapted to undulator beams at synchrotron radiation sources. The transmission ranges from a few % in aluminium CRLs up to about 30% expected in beryllium CRLs. The gain (ratio of the intensity in the focal spot relative to the intensity behind a pinhole of equal size) is larger than 100 for aluminium and larger than 1000 for beryllium CRLs. Due to their parabolic profile they are free of spherical aberration and are genuine imaging devices. The theory for imaging an X-ray source and an object illuminated by it has been developed, including the effects of attenuation (photoabsorption and Compton scattering) and of the roughness at the lens surface. Excellent agreement between theory and experiment has been found. With aluminium CRLs a lateral resolution in imaging of 0.3 µm has been achieved and a resolution below 0.1 µm can be expected for beryllium CRLs. The main fields of application of the refractive X-ray lenses are (i) microanalysis with a beam in the micrometre range for diffraction, fluorescence, absorption, scattering; (ii) imaging in absorption and phase contrast of opaque objects which cannot tolerate sample preparation; (iii) coherent X-ray scattering.

Optical head device

Abstract: It is provided an optical head device which includes: a light source; an objective lens, configured to converge light emitted from the light source to an information recording surface of an optical disk; a beam splitter, configured to deflect returned light reflected by the optical disk into an optical path which is different from an optical path of the light emitted from the light source; a photo detector, configured to detect the returned light deflected by the beam splitter; and a depolarizing element, disposed on an optical path between the beam splitter and the photo detector, and configured to cause the returned light to transmit through while reducing a degree of polarization of the returned light.

High-throughput, maskless lithography system

Abstract: A microscopy and/or lithography system uses a comparatively low-resolution image projection system, which has a very small numerical aperture but large image field, in conjunction with a microlens array comprising miniature lens elements, each of which has a large numerical aperture but very small field. The projection system contains a small aperture stop which is imaged by the microlenses onto an array of diffraction-limited microspots on the microscope sample or printing surface at the microlens focal point positions, and the surface is scanned to build up a complete raster image from the focal point array. The system design thus circumvents the tradeoff between image resolution and field size which is the source of much of the complexity and expense of conventional wide-field, high-NA microscopy and microlithography systems. The system makes possible flat field, distortion-free imaging, with accurate overlay, focus, and warp compensation, over very large image fields (larger than the practical limits of conventional imaging means). The image source may be a spatial light modulator such as a Grating Light Valve.

Penetrating endoscope and endoscopic surgical instrument with cmos image sensor and display

Abstract: A penetrating endoscope (10) provides visualization of organ or tissue structures of foreign objects in a body. The penetrating endoscope includes an elongate penetrating member (12), a complementary metal dioxide semiconductor (CMOS) image sensor (42), and an objective lens (36). The CMOS image sensor is substantially planar, and includes a plurality of pixels with a pixel signal processing circuit for generating a color image ready signal. The CMOS image sensor converts image light energy into electrical color image ready signal energy for transmission out of the body. The color image ready signal is viewed on a color image display (128). The CMOS image sensor is carried on the elongate penetrating member adjacent a distal end of the elongate penetrating member. The objective lens is also carried on the distal end of the elongated penetrating member on an optical axis, and focuses an image corresponding to an endoscope field of view at an image plane intersecting the optical axis.

HST Observations of 10 Two-Image Gravitational Lenses

Abstract: We report on a program to obtain HST observations of galaxy-mass gravitational lens systems at optical and infrared wavelengths. Here we discuss the properties of 10 two-image gravitational lens systems (Q0142-100=UM673, B0218+357, SBS0909+532, BRI0952-0115, LBQS1009-0252, Q1017-207=J03.13, B1030+074, HE1104-1805, Q1208+1011, and PKS1830-211). We grouped these 10 systems because they have limited lens model constraints and often show poor contrast between the images and the lens galaxy. Of the 10 lens galaxies, 7 are probably early-type galaxies, 2 are probably late-type galaxies (B0218+357 and PKS1830-211), and one was not detected (Q1208+1011). We detect the host galaxies of the z_s=4.50 lensed quasar in BRI0952-0115, the z_s=2.32 lensed quasar in HE1104-1805, and the unlensed z=1.63 quasar near LBQS1009-0252. We fit a set of four standard lens models to each lens that had sufficient constraints to compare isothermal dark matter and constant mass-to-light lens models, and to explore the effects of local tidal shears.

Control optimization of spherical modal liquid crystal lenses

Abstract: Liquid crystal modal lenses are switchable lenses with a continuous phase variation across the lens. A critical issue for such lenses is the minimization of phase aberrations. In this paper we present results of a simulation of control signals that have a range of harmonics. Experimental results using optimal sinusoidal and rectangular voltages are presented. A lack of uniqueness in the specification of the control voltage parameters is explained. The influence of a variable duty cycle of the control voltage on an adaptive lens is investigated. Finally we present experimental results showing a liquid crystal lens varying its focal length.

Lenses capable of post-fabrication power modification

Abstract: The present invention relates to lenses that are capable of post-fabrication power modifications. In general, the inventive lenses comprise (i) a first polymer matrix and (ii) a refraction modulating composition that is capable of stimulus-induced polymerization dispersed therein. When at least a portion of the lens is exposed to an appropriate stimulus, the refraction modulating composition forms a second polymer matrix. The amount and location of the second polymer matrix may modify a lens characteristic such as lens power by changing its refractive index and/or by altering its shape. The inventive lenses have a number of applications in the electronics and medical fields as data storage means and as medical lenses, particularly intraocular lenses, respectively.

Miniature image acquistion system using a scanning resonant waveguide

Abstract: A minimally invasive, medical, image acquisition having a flexible optical fiber serving as an illuminating wave guide. In one resonance mode, the distal end of the fiber is a stationary node. The fiber includes a lens at the distal tip which collimates emitted light. A scan lens is positioned off the end of the fiber. The relative magnifications of the lenses and the relative positions determines the pixel resolution. In particular, the illumination fiber outputs a light beam or pulse which illuminates a precise spot size. A photon detector detects reflected photons from the object, including the spot. Pixel resolution is determined by the area of the illumination spot (and thus the lens configuration), rather than an area sensed by the detector.

Method and apparatus for the interactive display of any portion of a spherical image

Abstract: Apparatus for interactive display of any portion of a spherical image preferably comprises a personal computer or other digital processor apparatus for storing digital data representative of at least one image having a 180 degree or greater field of view (or hemispherical image). In order to view a selected image portion without warp or distortion at the seam between opposite hemispherical images, edge filtering is applied to eliminate a halo effect. Moreover, an opposite hemispherical image may either be obtained by creating a mirror image of a first hemispherical image or by capturing a second hemispherical image by means of an oppositely directed camera and storing the digital image. Equations for image transformation are based on a lens' characteristics including the lens' radius R. An input interface preferably comprises a display including a magnification region and a directional cursor for pointing the direction to a next spherical image. “Hot spots” can be linked to audio, text, graphics, or other media or trigger a charge for a pay event or identify program links to the next spherical image.

Illuminating apparatus, display panel, view finder, video display apparatus, and video camera mounting the elements

Abstract: Light emitted from a white LED 15 is converted by a lens 11 into light having an excellent directionality. The light illuminates a display panel 863 from the direction of an angle θ k . The display panel 863 is a polymer dispersed liquid crystal display panel in a normally white mode. The display panel 863 modulates incident light by scattering it, the scattered light is incident on a magnification lens 866 , and light from the magnification lens reaches an eye 21 of the observer. Light which passes straight through a liquid crystal layer in the display panel 863 is absorbed by an optical absorbing film 12 . The observer fixedly positions his/her eye 21 to an eyepiece cover 852 and observes the displayed image.

Imaging system for vehicle headlamp control

Abstract: An imaging system for use in a vehicle headlamp control system includes an opening, an image sensor, a red lens blocking red complement light between the opening and the image sensor, and a red complement lens blocking red light between the opening and the image sensor. Each lens focuses light onto a different subwindow of the image sensor. The imaging system allows processing and control logic to detect the presence of headlamps on oncoming vehicles and tail lights on vehicles approached from the rear for the purpose of controlling headlamps. A light sampling lens may be used to redirect light rays from an arc spanning above the vehicle to in front of the vehicle into substantially horizontal rays. The light sampling lens is imaged by the image sensor to produce an indication of light intensity at various elevations. The processing and control logic uses the light intensity to determine whether headlamps should be turned on or off. A shutter may be used to protect elements of the imaging system from excessive light exposure.

Light generator for introducing light into a bundle of optical fibers

Abstract: The light generator comprises a housing (1) with a light source in the form of a plurality of LEDs (3, 3′, . . . ), each having a luminous flux of at least 5 lm during operation. The housing (1) also comprises a collimating lens (6) and a Fresnel lens (8) for focusing the beam generated by the LEDs (3, 3′, . . . ). The light engine is further provided with drive means in a box (10) for driving the LEDs (3, 3′, . . . ). Preferably, the collimator lens (6) has a number of sub-lenses (7, 7′, . . . ), the optical axis of each of the sub-lenses coinciding with the optical axis of a respective one of the LEDs (3, 3′, . . .).

3d imaging system

Abstract: An optical imaging system comprising: a taking lens system that collects light from a scene being imaged with the optical imaging system; a 3D camera comprising at least one photosurface that receives light from the taking lens system simultaneously from all points in the scene and provides data for generating a depth map of the scene responsive to the light; and an imaging camera comprising at least one photosurface that receives light from the taking lens system and provides a picture of the scene responsive to the light.

Zoom lens system

Abstract: A zoom lens system has, from the object side, a first lens unit, a second lens unit and a third lens unit The first lens unit has a negative optical power as a whole The second and third lens units have a positive optical power as a whole In the zoom lens system, zooming is achieved by varying the distance between the first and second lens units, and at least one of the lens elements is a plastic lens element

Dielectric lens, dielectric lens antenna including the same, and wireless device using the same

Abstract: The invention provides a dielectric lens, wherein the dielectric lens is rotation-symmetrically shaped, and a flat end is disposed at a part of the edge the dielectric lens. By the above described structure and arrangement, it become possible to widen a half-value angle in the direction which the flat ends of the lens are disposed without reducing a gain significantly.

Dielectric Loaded Antennas

Abstract: The sections in this article are 1 Dielectric Lens Antennas 2 Effect of Lens on Amplitude Distribution 3 Aberrations 4 Zoned Lenses 5 Reflection from Lens Surface 6 Lenses with n < 1 7 Constrained Lenses 8 Inhomogeneous Lenses 9 Dielectric Loaded Horns 10 Dielectric Loaded Waveguides 11 Microstrip and Dielectric Resonators 12 Insulated Antennas 13 Medical and Biological Antennas

Apparatus and method for measuring vision defects of a human eye

Abstract: Optical characteristics, including vision defects, of optical systems, such as the eye, are measured using a collimated beam from a diode laser focused at a position relative to the eye other than the retina for providing a finite source of secondary radiation on the retina of the eye, the image of which is close to a desired diffraction-limited spot. The secondary radiation is reflected back from the retina as a reflected wavefront of radiation that passes through the eye and is directed onto a wavefront analyzer where distortions associated with the reflected wavefront are measured. By focusing on the cornea through a long-focal-length lens and thus converging the beam through a small angle, as opposed to focusing a collimated light onto the retina, the need for lenses or lens combinations and the time required to adjust such to accommodate the different visual characteristics of each patient is eliminated.

Voltage-controlled ferroelectric lens phased arrays

Abstract: A new concept for phased arrays is proposed using a voltage-controlled ferroelectric lens. The ferroelectric lens concept uniquely incorporates bulk phase shifting-the array does not contain individual phase shifters-using ferroelectric material. This will reduce the number of phase shifters from (n/spl times/m) to (n+m), where n is the number of columns and m is the number of rows in a phased array. The number of phase shifter drivers and phase shifter controls is also significantly reduced by using row-column beam steering. Thus, the ferroelectric lens concept can potentially lead to low-cost phased arrays. This paper presents the ferroelectric lens concept, theoretical analysis and design, and experimental results. The results indicate that the ferroelectric lens concept is viable and sound. Various phased-array configurations using ferroelectric lens are included. A discussion on ferroelectric materials is included along with information on a US Department of Defense program to improve ferroelectric materials.

Wafer processing techniques for near field magneto-optical head

Abstract: A method of making and self-aligning a disk data storage read/write head that uses a catadioptric focusing device (or lens) having a high numerical aperture (NA), which does not introduce significant spot aberration on a storage medium. The manufacturing process of the head is carried out at a wafer level, and is facilitated significantly by the flatness of the focusing device. An exemplary manufacturing process is implemented as follows: A lens coil/plate is formed by molding a flat optical substrate to form the desired lens shapes. Coil cavities or depressions are formed simultaneously with the lens to accommodate a coil. Conductive plugs are formed in proximity to cutting lines for wire bonding attachment to the coil. A slider wafer is formed and bonded to the lens/coil wafer. Coils and pedestals are also formed on the lens/coil plate using thin-film processing techniques, and reflective surfaces are deposited on the bottom surface of the substrate, opposite the lens. The focusing device includes an incident surface, a reflective surface, a focal pedestal, and a body. The incident surface is generally flat and is comprised of a central diffractive, optically transmissive surface and a peripheral reflector. The peripheral reflector is comprised of a reflective-diffractive surface, or alternatively, a reflective-kinoform phase profile.

Progressive addition lenses

Abstract: The present provides progressive addition lens designs and lenses in which unwanted lens astigmatism is reduced as compared to conventional progressive addition lenses.

Applications of Liquid Crystals to Variable-Focusing Lenses

Abstract: Liquid Crystal (LC) lens cells with variable focusing properties are fabricated using nematic LC materials and applicable to optical devices, and our recent work on these cells is described. First, the LC lens cells are prepared using lens-shaped substrates coated with transparent electrodes. Their focal length can be continuously varied between the values for an ordinary ray and an extraordinary ray by changing the voltage passing across them. Methods of improving properties and some applications of the lens-shaped LC lens are briefly described. The lens properties of these cells with plane-paralleled structure are then demonstrated, where the refractive index is graded to a quadratic distribution resulting from an axially symmetric non-uniform electric field. LC cells with axially distributed tilt angles are constructed using a pair of circular hole-patterned electrode substrates and very small LC lens (LC microlens) with variable focusing can be fabricated. Optimizing the electrode structure, device parameters, and material parameters of the LCs, excellent focusing properties can be obtained. The properties of the LC microlens are improved by using the polymer stabilization technique. The LC microlens with a divided electrode structure shows three-dimensional beam steering and focusing properties, and the astigmatic aberration caused by the molecular orientation effect can be compensated. Applications of the LC microlens to optical devices and systems are introduced.

Multifocal lenses compensate for chromatic defocus in vertebrate eyes.

Abstract: The focal length of the vertebrate eye is a function of wavelength, i.e. the eye suffers from longitudinal chromatic aberration. Chromatic defocus is a particularly severe problem in eyes with high light-gathering ability, since depth of field is small due to a pupillary opening that is large in relation to the focal length of the eye. Calculations show that in such eyes only a narrow spectral band of light can be in focus on the retina. For the major part of the visual spectrum, spatial resolution should be limited by the optics of the eye and far lower than the resolving power achievable by the retinal cone photoreceptor mosaic. To solve this problem, fishes with irises unresponsive to light have developed lenses with multiple focal lengths. Well-focused images are created at the wavelengths of maximum absorbance of all spectral cone types. Multifocal lenses also appear to be present in some terrestrial species. In eyes with mobile irises, multifocal lenses are correlated with pupil shapes that allow all zones of the lens, with different refractive powers, to participate in the imaging process, irrespective of the state of pupil constriction.