摘要:
Three-dimensional (3-D) topographic data defining a remote surface in terms of the 3-D positions of M.times.N sample points on that surface may be obtained by (1) illuminating the scene with an array of M.times.N (simultaneous) laser beams, (2) sequencing the array of laser beams through a series of mathematical patterns (space coding) by means of a programmable electro-optic shutter, (3) recording by an imaging device the illumination reflected from the surface during the projection of each mathematical pattern, (4) analyzing the images to obtain the three-dimensional locations of each of the M.times.N illuminated points on the surface which are visible to the camera or imaging device, and (5) determining which of the laser beams in the array are not visible to the imaging device. (N and M are any positive integers consistent with the device proposed; typically M=N=128, so that M.times.N=16384 points.) Mechanization for rapid three-dimensional mapping of the surface involves an array of laser beams illuminating the surface, a programmable electro-optic shutter to switch on and off subsets of laser beams in the array and thereby to input the space code projected on the surface, a (usually narrow bandpass) video camera to capture the reflected images of the space coded surface from a given perspective (and if necessary from various other aspect angles), and a device to synchronize the electro-optic shutter with the video camera. Space coding of the light beams is used to correlate each spot seen on the surface with the corresponding beam in the laser beam array. A space code for an array of beams arranged in M rows and N columns reduces the number of images, I, necessary for correlating all light spots seen on the surface to I=l+log.sub.2 N where N is also the number of columns of the electro-optic shutter whch can be individually switched. The device achieves 3-dimensional topographic mapping much faster than laser rangefinder and optical devices because it can locate M.times.N surface points with only l+log.sub.2 n images (or patterns); it has much greater signal to noise capability than conventional light devices (it can work in daylight for a great variety of surface textures and uses non-moving, vibration-free components during data collection), and it is unambiguous in its mathematical results for all illuminated and visible surface points within its operating range.The invention differs from stereophotogrammetry by using one "active" device (the laser beam array) and one passive camera rather than two passive cameras as in conventional stereophotogrammetry. A system of several "active" devices (laser beam arrays) and several passive cameras is also comprehended if the object to be interrogated is very rough, convoluted, or has many sides.
摘要:
A first laser beam is reflected from the front and rear surfaces of a partially silvered glass slab generating a diverging set of interference fringes which are collimated by a positive lens. A second set of fringes is generated by a second laser beam and second partially silvered glass slab and is positioned to project through the first slab and is collimated by the same positive lens. The second pattern is aligned coaxially and mutually perpendicular to the first pattern creating a rectangular parallopiped grid pattern projected upon an observed object.
摘要:
Apparatus for simultaneously generating a space volume-filling structural light beam array utilizes a prism assembly which refracts a laser light beam so as to partition it into four separate segments. The four segments produced the two-by-two rectangular beam array by coherent interference of the segments.
摘要:
A ribbon-of-light projection system projects a substantially uniform ribbon of laser light (or other electromagnetic radiation) using a fiber-optic bundle, piano-mirrors, and a piano-cylindrical lens. Incidence optics directs a laser beam to be incident to the fiber-optic bundle at a predetermined angle of incidence, resulting in the projection of a sheet of light. The sheet of light is then projected towards the cylindrical lens where it is collimated into a ribbon. For the exemplary embodiment, the angle of incidence is orthogonal to the fiber-optic bundle. Thus, the laser projection system converts a beam of laser light (or other electromagnetic radiation such as UV, visible, IR or microwave radiation) into a collimated ribbon of light that in the exemplary embodiment is substantially uniform. In one application, the laser projection technique can be used in industrial applications to monitor the flow of fluids.
摘要:
A highly versatile optical mount fabricated from a single solid structural body provides accurately centered secured fixturing of a large array of optical components or objects. Fixturing is provided by a unique screw-tensioned strapping mechanism.
摘要:
A computer or remote controlled end effector articulating mechanism provides accurate and independent seven axis actuation of an operator such as a tool, platform, sensor, biological specimen or other object such as a workpiece. The object(s) or operator(s) may be mounted on end effector element 7 which is linearly translated 9 along axis 5 and rotated 2 about the same axis by conventional computer or remotely controlled linear actuator and rotator mounted on or within element 11. Element 11 is in turn linked to a further mechanism comprised of pivot axes 13, 15, 21, 23, 25, 45 and 47 connected to linkage elements 17, 19, 22 and 43. These linkages are connected to a rotatable axle 29. Orthogonal rotary motion is imparted to these linkages by mechanism 30 comprised of 27, 29, 31, 33, 35, 37, 39, 41, 43, 51, 53, 55, 57, and 59. The orthogonal rotary motion imparted by mechanism 30 actuates 11 hence element 7 to move about orthogonal spherical coordinate paths 4 and 6 centered at point 1, the intersection of axis 5 and axis 3. Linear actuation is further imparted on the intercept point 1 by orthogonally arranged serially connected linear translators 61, 63, and 65, a fixed to stationary fixture 67. Thus, there is totally independent x, y, z translation of a three-axis spherical coordinate articulated mechanism with an added twist about the spherical coordinate radius vector.
摘要:
A cone-of-light projection system projects a shell of laser light (or other electromagnetic radiation) using a fiber-optic bundle. Incidence optics directs a laser beam to be incident to the fiber-optic bundle at a predetermined angle of incidence, resulting in the projection of a conical shell of light. For the exemplary embodiment, the angle of incidence is non-orthogonal to the fiber-optic bundle, resulting in the projection of a conical shell of light. Thus, the laser projection technique converts a beam of laser light (or other electromagnetic radiation such as UV, visible, IR or microwave radiation) into a conically extending shell of light that in the exemplary embodiment is substantially conical. In one application, the laser projection technique can be used in industrial applications to assist in joining a cylindrical element to another surface.
摘要:
An economical computer-controlled non-invasive laser apparatus and method to perform anterior segment surgery in an eye are disclosed. The laser source may include a pumping laser, a Nd:YAG laser cavity gain media, a stimulated Raman converter crystal, intracavity beam diameter-reducing optics, and an intracavity Q-switching crystal. The laser pulses have a selected wavelength for anterior segment surgery. A laser pulse delivery and treatment control mechanism and method for the practicing surgeon are also provided. The laser pulses and delivery system may be used in anterior segment surgery for cataracts, where the laser pulses may be used to form the capsulotomy, to form the corneal incision or to disintegrate contents of the capsule before removal. The laser and delivery system may also the used to treat a capsule and lens for correcting or preventing presbyopia and to treat a cornea to correct visual deficiencies in an eye.
摘要:
An oximetry technique permits determination of hemoglobin oxygenation in vascular beds such as the inner retinal capillary beds. For a retinal application, an oximeter (FIG. 2) uses as a probe light source a multiline argon laser (11) that operates at three wavelengths in the hemoglobin absorption band, preferably 488, 501, and 514 nm. The oximeter optics module (30) attaches to the output end of a conventional slit lamp microscope (20). Reflected probe light is separated (34) into its constituent wavelengths, and photon counters (38) are used to measure light intensity for each wavelength. Data acquisition and analysis are performed by an oximeter processor (40) that computes hemoglobin oxygenation ratios from the intensity measurements, and determines the corresponding percent oxygen saturation.
摘要:
System and method for detection and measurement of airborne biological aerosol particles in a gaseous sample are described comprising a source of low energy radiation for irradiating the gaseous sample whereby biological particles in the sample are ionized, a detector for detecting ionized biological particles in the sample including a pair of electrically charged conducting plates disposed in parallel confronting relationship to each other with a preselected space therebetween, a source of electrical power operatively connected to the plates for applying a preselected electrical potential thereacross, and electronics for sensing collisions on the plates of ionized biological particles in the sample.