Abstract: A sheathed syringe assembly including a syringe having a cylindrical body provided with a needle at one end thereof and a plunger slideably disposed within said cylindrical body for aspirating or dispensing substances into or from the cylindrical body. A sheath assembly comprised of inner and outer tubular members is attached to the cylindrical body. The inner tubular member is telescopically received in the outer member for reciprocal movement therein between a retracted position exposing said needle and an extended position covering said needle to prevent accidental needle stick. The sheath assembly is provided with a ratchet means for manually advancing said inner tubular member into the extended position with the same hand holding said syringe assembly.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Dental x-ray film is properly aligned with the x-ray beam utilizing a plurality of infrared emitters and detectors that are positioned circumferentially about the path of the x-ray beam. A reflecting surface whose plane is parallel with the plane of the x-ray film holder and integral therewith can be positioned parallel to the plurality of emitters and sensors by repositioning until the sensors receive a predetermined reflective response. Each sensor activates an indicator light seen on a display and when all the lights in a bank of lights are activated alignment is achieved. The output of the sensors can also be summed and when the sum output reaches a predetermined value an oscillator is triggered thus creating an audible tone indicating proper alignment.