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Showing papers on "Parabolic reflector published in 1995"


Patent
02 May 1995
TL;DR: A lamp matrix display as mentioned in this paper includes a vertical planar array of light sources arranged in rows and columns and a plurality of reflectors positioned about corresponding light sources and having reflector surfaces for directing the light emitted from the light source in a forward direction.
Abstract: A lamp matrix display includes a vertical planar array of light sources arranged in rows and columns and a plurality of reflectors positioned about corresponding light sources and having reflector surfaces for directing the light emitted from the light source in a forward direction. The reflective surface of at least one of the reflectors includes multiple parabolic reflective surfaces having offset focal points. At least one lens is mounted in front of the reflectors. The lens may be a single lens having an inner flat surface disposed adjacent an outer edge of each reflector surface and an outer prismatic surface having vertical prisms to horizontally spread the light from the planar array of light sources. Further, the plurality of reflectors may be structurally supported about corresponding light sources by a matrix framework and the matrix framework may include a plurality of air vents.

31 citations


Patent
26 Jan 1995
TL;DR: In this article, a parabolic reflector is rotated about a stationary light source to create a beacon, and a low profile stepper motor is used to rotate the reflector about the light source.
Abstract: A parabolic reflector (14) is rotated about a stationary light source (12) to create a beacon. A low profile stepper motor (30) includes a centrally located spindle (34) having a socket (35) in which the light source (12) is placed. A hub (50) fits over the spindle (34). The hub (50) includes a slot (57) that receives a corresponding tab (16) on the parabolic reflector so that, as the low profile stepper motor (30) rotates, the parabolic reflector (14) is rotated about the light source (12).

23 citations


Patent
12 Dec 1995
TL;DR: In this paper, the authors described a method for concentrating the energy of laser diode beams by imaging them to obtain a superimposed image and a combined numerical aperture at a focal plane.
Abstract: Methods and apparatus are disclosed for concentrating the energy of laser diode beams (24) by imaging them to obtain a superimposed image and a combined numerical aperture at a focal plane (26) and by guiding them between reflective boundaries (70, 72) to maintain a lesser second numerical aperture at the focal plane. The combined numerical aperture preferably matches the second numerical aperture so that the energy can be received into the entrance end (102) of optical fibers (100) whose numerical apertures also match the second numerical aperture. A described embodiment utilizes collimating lenses (36) and an off-axis parabolic reflector (38). The exit ends (108) of the optical fibers can be grouped and fractionally magnified into a concentrated energy pattern. The final image can be imposed into a single optical fiber (30) for passage along remote or convoluted optical paths.

19 citations


Proceedings ArticleDOI
10 Apr 1995
TL;DR: Acept for the unfolding deployment of doubly curved surfaces via the use of incisions to transform them, without affecting their integrity or shape, into foldable mechanisms is proposed, and the application of this concept to parabolic reflectors is investigated.
Abstract: A wncept for the unfolding deployment of doubly curved surfaces via the use of incisions to transform them, without affecting their integrity or shape, into foldable mechanisms is proposed, and the application of this concept to parabolic reflectors is investigated. F i t , a general structural classification of deployable a n t e ~ a s is put forth, within the framework of which the wncept of incisions is presented. This is followed by the discussion of simple mechanical considerations relevant to the concept's application to parabolic antennas. Next, some options for the latter are qualitatively assessed and illustrated via breadboard demonstration models. Finally. conclusions are drawn and functional, manufactwing, as well as further research concerns are summarized.

9 citations


Journal ArticleDOI
TL;DR: In this article, the influence surface for each adjustment is computed using a detailed finite-element model of the antenna and the reflector structures, and the optimal adjustments that minimize surface RMS are obtained using the computed influence surfaces by solving a quadratic programming problem.
Abstract: The primary reflector panels of the 37-m (120-ft) diameter Haystack antenna are prestressed to form an integrated parabolic shell of revolution. The adjustment mechanisms of the reflector surface are highly interacting, and the region of influence of each adjustment mechanism is large and intersects in a major way the influence regions of other adjustment mechanisms. The influence surface for each adjustment is computed using a detailed finite-element model of the antenna and the reflector structures. The optimal adjustments, i.e. the adjustments that minimize surface RMS, are obtained using the computed influence surfaces by solving a quadratic programming problem. The resolution of holography introduces errors in the holography map, but the resulting error in the computed adjustments are eliminated by using, in lieu of the actual influence surfaces, the transformed influence surfaces obtained by the convolution of the actual influence surfaces with the holography resolution function. The procedure, which was used to reduce surface RMS of the Haystack from 639 micron (25.1 mil) to 194 micron (7.6 mil), is applicable to other antennas. >

9 citations


Patent
13 Oct 1995
TL;DR: In this paper, a data transmitting/receiving satellite terminal for transmitting to and receiving from a geosynchronous satellite (11) employs an antenna (15A, 15B) having nulls in its antenna receiving pattern at a first frequency corresponding to satellites spaced at regular intervals from the satellite.
Abstract: A data transmitting/receiving satellite terminal for transmitting to and receiving from a geosynchronous satellite (11) employs an antenna (15A, 15B) having nulls in its antenna receiving pattern at a first frequency corresponding to satellites spaced at regular intervals from the satellite. In addition, a phase and amplitude compensation network (23A, 23B) adjusts a phase and amplitude of the transmitted signal to compensate for transmitting at a different frequency than for which the antenna is optimally designed. The antenna includes a main parabolic reflector, and two side parabolic reflectors offset from a plane parallel to the main parabolic reflector. Each of the reflectors uses a dual frequency feed horn to couple energy to and from the reflector to a dipole exciter to which the receiving electronics are coupled. The above terminal is particularly useful in C-Band applications.

8 citations


Patent
09 May 1995
TL;DR: In this paper, a parabolic mirror is used to separate visible and long-wavelength light, and the visible light is converted into reflected cold light and collected by the mirror, and this light is applied to a light-converging solar cell.
Abstract: PURPOSE: To make effective use of sunlight for a number of purposes by means of an inexpensive, compact device by converging light while separating it according to wavelengths by means of a lens provided inside a reinforced glass tube capable of rotation for tracking the light, and performing light-converging power generation and heating of a heat medium to high temperatures. CONSTITUTION: A direct incident beam 7, which is incident with a perpendicular optical axis to the sun and from above a reinforced glass tube 1 as the sun is tracked, is separated by a silicone-coated parabolic mirror 12 into visible and long-wavelength light. The visible light is converted into reflected cold light 8 reflected and collected by the mirror 12, and this light is applied to a light-converging solar cell 4 bonded to the underside of a low-temperature cooling unit 5, so that the cell 4 generates electricity. The ultraviolet radiation of the transmitted heat and light 9, that is the long-wavelength light transmitted through the mirror 12, is converged and accumulated in a vacuum heat-absorbing tube 6 at the center as reflected heat and light 13 by means of a parabolic mirror 11 located beneath the tube 1, to heat a heat medium in the tube 6. Therefore, the high-temperature heat medium can retained without temperature drops and be used effectively along with the electromotive power of the cell 4 for a number of purposes.

6 citations


Journal ArticleDOI
TL;DR: In this article, the effects of reflectors with different depths and of the incident shock Mach numbers on the effect of a plane's focusing on a concave reflector were investigated.
Abstract: The problem of a plane shock wave that propagates in an air media and then is reflected from a parabolic concave reflector and focuses at some region is considered. The shock focusing can greatly magnify the pressure and the temperature. The purpose of this study is to numerically simulate the shock focusing process of the reflection of shock waves from the parabolic reflectors with different depths and to analyze their associated flow fields in detail. The present solver developed is to solve the Euler equations using an improved, implicit, upwind Total Variation Diminishing scheme in a finite-volume approach. The effects of reflectors with different depths and of the incident shock Mach numbers on shock focusing are investigated. The real-gas effect is taken into account through a proper correction of the specific heat ratio of air, when high temperature occurs due to shock focusing.

6 citations


Journal Article
TL;DR: In this paper, the authors present different numerical tools useful for simulating laser beam propagation in an off-axis optical system and for computing power losses in order to give specifications to the system.
Abstract: We present different numerical tools useful for simulating laser beam propagation in an off-axis optical system and for computing power losses in order to give specifications to the system. We first recall the basis of Fourier-transform beam-propagation, and then we calculate the phase factor corresponding to an off-axis reflection on an optical surface (spherical or parabolic mirrors). We then develop an extension of the Fourier-transform beam propagation method to compute the propagation through a plane parallel plate, frequently used to compensate for astigmatism. We give numerical examples, involving a two mirrors off-axis beam expander.

6 citations


Patent
28 Sep 1995
TL;DR: In this article, a planar millimeter wave antenna is described formed of a sandwich structure having an upper planar phased array made from an etched metallized layer of dielectric material and a lower metallised layer having a guided wave feed, where millimeter waves are coupled between the waveguides with a desired distribution in the upper waveguide to enable the formation of a desired antenna beam from the phased array.
Abstract: A planar millimeter wave antenna is described formed of a sandwich structure having an upper planar phased array made from an etched metallized layer of dielectric material and a lower metallized dielectric layer having a guided wave feed. With the upper and lower dielectric layers forming parallel plate waveguides which are coupled to each other at a boundary zone having a parabolic reflector whereby millimeter waves are coupled between the waveguides with a desired distribution in the upper waveguide so as to enable the formation of a desired antenna beam from the phased array. Multiple feeds are described and spaced from the parabolic axis in order to create different azimuthal beams which have a desired angular spacing from each other. A circular polarized phased array formed of angled slits is described for the upper metallized layer.

6 citations


Patent
25 Jul 1995
TL;DR: In this article, the output mirror of the Q switch of a pulse CO2 has been used to stabilize a resonator alignment and to improve core loss improving efficiency as well as the increase in the frequency and output by constituting a partial reflector having a recessed face on the resonator side.
Abstract: PURPOSE:To stabilize a resonator alignment and to improve core loss improving efficiency as well as the increase in the frequency and output by constituting the output mirror of the Q switch of a pulse CO2.laser irradiating device used for magnetic domain fractionating of a partial transparent mirror having a meniscus shape. CONSTITUTION:In a Q switch CO2.laser device in which a resonator is constituted of a confocal telescope and a rotary chopper 6, among the optical system constituting the telescope, a condensing optical element on the output side is constituted of an output mirror 4 constituted of a partial reflector with a meniscus shape having a recessed face on the resonator side. The curved shape of both sides of the laser output mirror 4 having a meniscus shape is formed into a spherical face, and the condensing optical element is formed of transmissive condensing lens having a spherical or nonspherical face. Furthermore, it is constituted of a condensing optical system formed of a Q switch CO2.laser in which the condensing shape of a laser at the position of the confocal point of the telescope is formed into a dot one, a polygon mirror 8 and a parabolic mirror 9.

Patent
10 May 1995
TL;DR: A light source suitable for use in a projection system is described in this article, where the light source is in a form of an arc lamp including an arc gap defined between an anode and a cathode.
Abstract: A light source suitable for use in a projection system is described. The light source is in a form of an arc lamp including an arc gap defined between an anode and a cathode. The arc gap is positioned at the focal point of a parabolic reflector which is truncated at its focal plane. A spherical reflector oppositely directed to the parabolic reflector and concentric with the focal point of the parabolic reflector is arranged so as to direct light from the arc which has not been intercepted by the parabolic reflector back into the arc gap.

Patent
21 Jul 1995
TL;DR: The headlamp has a light source facing the end of an optical bar and a parabolic reflector behind the light source is used to focus light onto the optical bar as mentioned in this paper.
Abstract: The headlamp has a light source (1) facing the end of an optical bar The optical bar (3) is made up of multiple stepped facets (5) A parabolic reflector (2) behind the light source focuses light onto the end of the optical bar A mirror (4) is positioned at the end of the bar that receives the light The mirror can be tilted to various positions, directing the incoming light so it arrives at the optical bar at differing angles The mirror has one plane face and the other face cut in two planes at an angle to each other The third position is with the mirror turned edge on to the incoming light, allowing the light directly on to the end of the optical bar

Proceedings ArticleDOI
07 Apr 1995
TL;DR: In this article, a compound orthogonal parabolic reflector is proposed to focus a relatively large light source into a very small point, which creates an ideal intense point source for all next generation image display systems.
Abstract: This paper will review the currently available light sources, and also introduces a new,patented compound orthogonal parabolic reflector to be integrated with the light source,which focuses a relatively large light source into a very small point. The reflector creates anearly ideal intense point source for all next generation image display systems. Theproposed system is not limited by the radiation source whether it is a an short arc lamp or along tungsten filament lamp. Our technologies take the finite size of radiation sources intoaccount to address the common problem for all reflector lamp systems, i.e., intensity anduniformity (dark hole). Successful examples will be shown on how to make the efficientintense light source match the requirements of LCD and DMD (Ref. 1 ) display systems. Amethod for reducing U.V. and l.R. radiation will also be demonstrated.Keywords: Projection, intensity, uniformity, efficiency.1. INTRODUCTION To date, image display brightness is still the limiting factor of all large screen projection

Patent
29 Dec 1995
TL;DR: A rotatable reflector dish for collecting and concentrating solar radiation for the generation of electrical power is pivoted to one side so as to be positioned between a vertical position or lowered to a horizontal position as mentioned in this paper.
Abstract: A rotatable reflector dish for collecting and concentrating solar radiation for the generation of electrical power (3) is pivoted to one side so as to be positioned between a vertical position or lowered to a horizontal position. When horizontal the dish is protected by a surrounding weathershield (13) for protection against high winds. The reflector dish is preferably parabolic and mounted so as to concentrate and reflect the solar radiation into a receiver (5). The receiver comprises a cavity, the walls of which absorb incident solar radiation and conduct its heat to a working fluid. A parabolic reflector dish may comprise a plurality of planar reflective segments.

Patent
16 Jun 1995
TL;DR: In this paper, the authors measured the shapes of various kinds including slant faces different in angle of inclination stably by radiating plural lasre lights at different angles of incidence by use of a parabolic mirror and receiving reflected light in the vertical direction and in the direction of regular reflection to selectively measure the height and quantity of light.
Abstract: PURPOSE:To measure the shapes of various kinds including slant faces different in angle of inclination stably by radiating plural lasre lights at different angles of incidence by use of a parabolic mirror, and receiving reflected light in the vertical direction and in the direction of regular reflection to selectively measure the height and the quantity of light CONSTITUTION:Lasers 3, 4, 5 of different wavelengths are composed on the same optical axis through a first dichroic mirror 6 The laser light is scanned 7 in the horizontal direction, the scanned laser light is converged to a required beam diameter by the measuring surface of a measurement stage 1, further dispersed by a second dichroic mirror 10 through a ftheta lens 8 for keeping the scanning speed constant and a mirror 9 for reflecting in the vertical direction, and further reflected by a parabolic mirror 11 to enter the stage 1 at different angles of incidence The reflected light in the direction of regular reflection on a flat surface is received by a photo detecting element 14 through a converging lens 12 and a filter 13 The reflected light in the vertical direction is dispersed by a third dichroic mirror 16 through a second converging lens 15 and received by photoelectric transfer elements, 17, 18 and 19

Proceedings ArticleDOI
04 Feb 1995
TL;DR: In this paper, a dual-polarized, electronically scanned parabolic reflector is described that tracks and receives telemetry data from two missiles simultaneously, and beam steering is accomplished by means of a prime focus cluster-feed that is programmed using phased array processing techniques.
Abstract: A dual-polarized, electronically scanned parabolic-reflector is described that tracks and receive telemetry data from two missiles simultaneously. Beam steering is accomplished by means of a prime focus cluster-feed that is programmed using phased array processing techniques. The feed provides variable beamwidth and beamshape. Missile tracking is accomplished by employing a unique algorithm that maximizes signal-to-noise in the direction of the target. >

Patent
16 Jun 1995
TL;DR: In this paper, the laser beam transmitter consists of an incident side plane mirror, a side parabolic mirror, an exit side paraboloid mirror, and an exit-side plane mirror.
Abstract: PURPOSE:To obtain an intended beam profile while preventing lowering of beam strength, divergence of beam and disturbance of beam pattern. CONSTITUTION:The laser beam transmitter-comprises an incident side plane mirror 1a, an incident side parabolic mirror 2a, an exit side parabolic mirror 2b, and an exit side plane mirror 1b. The parabolic mirrors 2a, 2b are arranged such that a beam can impinge and reflect thereon while shifting the axes. The mirrors 1a, 1b, 2a, and 2b are arranged on a common plane.

Patent
23 Mar 1995
TL;DR: In this paper, a radar system is mounted on a pillar and emits beams to measure the speed of a vehicle (FZ) and also to provide identification, which is used to measure speed.
Abstract: The radar system is mounted on a pillar and emits beams to measure the speed of a vehicle (FZ) and also to provide identification. The radar scanner has a primary emitter (PS) with a parabolic reflector (RE) for producing a fairly flat beam (SV) via a part transmitting plate (TE). A further reflector (UR) aids in the generator of a rear, vertically-directed beam (SK) that provides identification of the vehicle. The flat beam is used to measure speed.


Patent
05 Dec 1995
TL;DR: In this paper, a parabolic reflector is attached to a mechanically stable receptacle, which is used to attach the reflector to a support, and the receptacle includes a metal ring with an L-shaped cross section in an opening that corresponds to a central opening in a reflector.
Abstract: An antenna includes a parabolic reflector and a supply line attached thereto. The supply line includes two rectangular electromagnetic (waveguides) that are essentially parallel to each other. A tube-shaped exciter is common to the (waveguides) and is located at open ends of the waveguides. A back side of the reflector has a mechanically stable receptacle, which is used to attach the reflector to a support. The receptacle includes a metal ring with an L-shaped cross section in an opening that corresponds to a central opening in the reflector. The ring has a cylindrical area and, at a right angle to the cylindrical area, a base area that extends toward the inside of the ring. In the installed position, the cylindrical area of the ring penetrates and is centered in the opening of the reflector. A holding plate, which firmly surrounds and supports both waveguides, fits precisely into the ring and is attached to the ring in removable form when mounted.

Proceedings ArticleDOI
04 Apr 1995
TL;DR: In this paper, the authors describe the results of an activity performed on the design of large and highly-shaped dual-gridded reflector antennas, and the critical aspects in developing a reflector shaping technique based on an optimization algorithm are discussed.
Abstract: Current and proposed satellite communications systems demand dual-linearly polarised transmit-receive antennas for contoured and/or multiple beam coverages. The proven means of satisfying these requirements is by the use of dual-gridded parabolic reflectors with two separated feed arrays radiating opposite linear polarizations. The two parabolic dishes are gridded in perpendicular directions and placed in front of one another with independent focal points to maintain separated the relevant feed arrays and beamforming networks. This paper describes the results of an activity performed on the design of large and highly-shaped dual-gridded reflector antennas. The critical aspects in developing a reflector shaping technique based on an optimization algorithm are discussed. The advantage in compensating for the effects of reflector thermal distortions during the electrical antenna design are also demonstrated. This novel technique allows a less critical thermal control of the reflector assembly, with a consequent reduction of the development time, hardware mass, and ohmic losses.

Journal ArticleDOI
TL;DR: In this article, the problem of the focal region fields scattered by an arbitrary surface reflector under uniform plane wave illumination is solved, and the physical-optics approximation is used to calculate the current induced on the reflector.
Abstract: The problem of the focal region fields scattered by an arbitrary surface reflector under uniform plane wave illumination is solved. The physical-optics (PO) approximation is used to calculate the current induced on the reflector. The surface of the reflector is described by a number of triangular domain-wise fifth-degree bivariate polynomials. A two-dimensional Gaussian quadrature is employed to numerically evaluate the integral expressions of the scattered fields. No Fresnel or Fraunhofer approximations are made. The relation of the focal fields problem to surface compensation techniques and other applications are mentioned. Several examples of distorted parabolic reflectors are presented and discussed.

Patent
12 May 1995
TL;DR: In this article, the polarization plane angle adjusting structure of a parabolic antenna capable of adjusting the angle of the polarization planes of a power feeding part without requiring dangerous operations is provided.
Abstract: PURPOSE:To provide the polarization plane angle adjusting structure of a parabolic antenna capable of adjusting the angle of the polarization plane of a power feeding part without requiring dangerous operations CONSTITUTION:The radio waves of CS broadcasting reflected by a parabolic antenna reflector 1 are received by a feed phone 2 arranged at the focus position The feed phone 2 is connected to a circular waveguide 3 extended to the back side of the parabolic reflector 1 and a circular/rectangular conversion part 10 constituted at the end part of the circular waveguide 3 and a converter part 11 are connected and constitute the power feeding part 4 The power feeding part 4 is provided with a rotary structure capable of adjusting the angle of the polarization plane of the received radio waves Then, CS-IF signals down- converted in the frequency converter part 11 of the power feeding part 4 are transmitted from an output connector to a CS tuner installed inside a house by a coaxial cable

Patent
05 Dec 1995
TL;DR: In this article, a head-up display for a vehicle is provided with a transmission type liquid crystal display element, a halogen lamp 102 for illuminating the liquid-crystal display element in the transmitting state, and an off-axis parabolic mirror 104 for irradiating the luminous flux.
Abstract: PURPOSE:To heighten the utilization efficiency of direct divergent luminous flux from an illuminating light source or/and the utilization efficiency of parallel luminous flux from a parabolic mirror so as to improve the utilization efficiency of luminous flux as the whole system. CONSTITUTION:A head up display for a vehicle is provided with a transmission type liquid crystal display element 101, a halogen lamp 102 for illuminating the liquid crystal display element 101 in the transmitting state, a parabolic mirror 103 for reflecting luminous flux from the halogen lamp 102 in the specified direction, and an off-axis parabolic mirror 104 for irradiating the luminous flux, reflected by the parabolic mirror 103, convergently to the liquid crystal display element 101. The luminous flux from the halogen lamp 102 is reflected in the specified direction by the parabolic mirror 103, and the luminous flux from the parabolic mirror 103 is convergently applied to the liquid crystal display element 101 by the off-axis parabolic mirror 104. The luminous flux of the halogen lamp 102 is thereby reflected sufficiently by the parabolic mirror 3 to heighten the utilization efficiency of the divergent luminous flux, and the luminous flux is converged to the size of the liquid crystal display element 101 by the off-axis parabolic mirror 104.

Proceedings ArticleDOI
07 Nov 1995
TL;DR: In this article, a parabolic shaped holder was designed with the piezoelectric element positioned in the focus, and the spherical wave was collimated in a quasi-plane wave on the parabolic focal surface.
Abstract: To perform an ultrasonic marble quarries reconstruction it is necessary to use an echographic method. At the employed frequencies, the commercially available transducers have an active emission surface diameter which is too small in comparison to the ultrasonic wavelength. As a consequence, a very wide radiation lobe propagation occurs leading to energy spreading and to surface propagation which masks the signal coming from the inner portion of the quarry. These effects make the echographic method inapplicable. The goal of our research is to realize a new sensor capable of increasing the ultrasonic beam directivity. A parabolic shaped holder was designed with the piezoelectric element positioned in the focus. By exploiting the parabolic reflector properties, the spherical wave is collimated in a quasi-plane wave on the parabolic focal surface.

Patent
06 Sep 1995
TL;DR: In this article, a multibeam antenna capable of receiving/transmitting signals at the same frequency, in one or more directions, simultaneously, essentially consisting of a parabolic reflector with square-shaped edge, being one of the four vertices of the square which circumscribes the reflector.
Abstract: of EP0670609Multibeam antenna capable of receiving/transmitting signals at the same frequency, in one or more directions, simultaneously, essentially consisting of one or more radiating elements (2), of a parabolic reflector (1) with square-shaped edge (3), being one of the four vertices (4) of the square which circumscribes the reflector (1) located close to the focal axis of the paraboloid. The radiating elements (2) and, correspondingly, the operating directions, are aligned along one of two possible orthogonal planes. The invention provides, with respect to previous solutions: maximum isolation between operating directions, at the same antenna gain; minimum size of the reflecting surface, since the rectangular shape reduces the overall dimensions and makes packaging - and therefore transportation - easier. Techno-scientific scope: space and non space antenna electronics; field of application: space antennas to be used especially for TV signals.

Patent
10 Jan 1995
TL;DR: In this article, the authors proposed a high power laser system for focusing a beam spot, and quickly executing operation by using a laser beam with a further large diameter and another large mirror, where the curvature of the mirror, lens, isolated distance of them, and incident angle of a divergent beam related to the optical axis of a mirror are set so that a convergent beam 35 can reach a focal point 36 whose astigmatic aberration is corrected.
Abstract: PURPOSE: To provide a high power laser system for focusing a beam spot, and quickly executing operation by using a laser beam with a further large diameter and a further large mirror. CONSTITUTION: A laser beam 28 is transmitted through an opening 54 of a supporting housing 55, and then transmitted through a negative(divergent) spherical lens 56. A cylindrical corrected divergent beam 31 is reflected by a first plane mirror 32 at an angle of 45 deg.. A divergent beam 31' is reflected to a large- scaled spherical or parabolic mirror 34 by a second plane mirror 33. The curvature of the mirror 34, lens 56, isolated distance of them, and incident angle of a divergent beam 31" related to the optical axis of the mirror 34 are set so that a convergent beam 35 can reach a focal point 36 whose astigmatic aberration is corrected. The position of the focal point 36 on a workpiece surface 37 is decided by the position of a plane scanning mirror 26.

Patent
24 May 1995
TL;DR: In this article, a high gain rotary TV aerial on balconies is described, which is composed of an aerial, a diverter, a mixer, an amplifier, an electric cable, etc.
Abstract: The utility model relates to a high gain rotary TV aerial on balconies, which is composed of an aerial, a diverter, a mixer, an amplifier, an electric cable, etc. The aerial is inserted into a metal pipe from a parabolic-shaped bracket to form a reflector, a director is composed of two layers of metal pipes, and folded oscillators and oscillators receive U frequency band and V frequency band TV signals. The utility model is conveniently installed on balconies, directions for receiving television signals are adjustable through the diverter, and the gain input into the TV is high through the amplifier, the parabolic reflector and the director.

Proceedings ArticleDOI
N. Ninane1
02 Aug 1995
TL;DR: The parabolic liquid mirror can be made by rotating a bath of mercury and the mirror focal length f is related to the angular speed of rotation (omega) and the gravity g by the formula: f equals g/2(DOT) 2.
Abstract: A parabolic liquid mirror can be made by rotating a bath of mercury. The mirror focal length f is related to the angular speed of rotation (omega) and the gravity g by the formula: f equals g/2(DOT)(omega) 2. Good quality mirrors having a diameter up to 3 meters have been built and, telescopes and lidar based on this technology are running. The greatest advantage of liquid mirrors is the cost. For a big mirror the cost is 1 or 2 orders of magnitude less than a conventional glass mirror and its cell. The idea developed here is that if a good parabolic mirror can be produced at low cost, this one can be useful in optical shop testing as reference mirror and can fill the lack of aspheric reference. The liquid mirror can be used to test null correctors, to make holographic references or to control any system developed to test parabolic mirrors.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.