Abstract: A transducer for measuring extremely small rates of flow of a liquid under high pressure. A transparent tube has a small channel within which is contained a ball having a diameter substantially that of the channel. The tube is housed in a pressure vessel in such a manner that the high pressure liquid to be measured surrounds the tube over most of its length. The liquid flows externally of the tube toward the inlet end of the channel, thereby equalizing the pressure differential within and without the tube. As the fluid passes through the channel from the inlet to the outlet, it propels the ball past a sensor, such as a photoelectric device. The velocity of the ball past the sensor indicates the volumetric flow rate of the fluid. The device is periodically reset by momentarily reversing the direction of flow through the tube to return the ball to its starting position.

Abstract: A flowmeter system for measuring the flow and changes in the velocity of sound due to changes in composition or temperature of a fluid medium in a flow tube including transducers which generate acoustic compression waves in the fluid medium, phase lock loop transmitter/receiver circuitry including device for measuring the difference in phase of the acoustic compression waves transmitted upstream relative to that received and for measuring the phase difference of the acoustic compression waves transmitted downstream relative to that received and producing a sum signal dependent upon the sum of the two measured phase differences, device for producing a difference signal proportional to the difference of the two measured phase differences which provides an output signal representing the direction and magnitude of the measured flow device for automatically adjusting the frequency of the acoustic compression waves so that their wave lengths remains constant, said means for automatically adjusting the frequency inc

Abstract: A magnetic lens, useful as an objective lens in a focused charged particle beam generator, includes means for maintaining a constant thermal power dissipation independent of the field strength produced thereby.

Abstract: An automatic focusing system for positioning silicon or other wafer within the focal plane of a photolithographic mask projection system. The position of the wafer is measured at a plurality of points and compared to the position of an optical flat located in the focal plane to provide signals for positioning the wafer at the focal plane of the projection system. The system also includes means for changing the contours of the wafer to cause it to lie in a known plane.

Abstract: The first element comprises a relatively thin transmissive shell concave toward the front. The second element comprises a mirror concave toward the front. The front surface of the shell may be spherical, and the rear surface aspheric, or vice versa. The central portion of the first element on either the front or back surface is mirrored to form the secondary of the system. Preferably the secondary mirror is on the front of the first element. In one embodiment the second element is also a transmissive shell. In one form of this embodiment the second transmissive shell is aspheric on the front and spherical on the back. In another form it is spherical on the front and aspheric on the back. In both of these forms the primary mirror is located on the back of the second element. In another embodiment the second transmissive element is aspheric on the front and flat on the back; the front surface being mirrored except for the central portion thereof, through which light from the secondary is focused.

Abstract: A spectrophotometer system has an optical system for transmitting a beam from a source at select wavelengths onto a detector. A plurality of filters are positioned in a tray. A stepper mechanism indexes the tray along a path. A microcomputer controls the stepper mechanism and the optical system. The wavelength is successively changed over a range, the tray is indexed to move a select filter into the beam at a predetermined wavelength and the changing is discontinued during indexing.

Abstract: In order to obtain shorter exposure time and to obtain a longer life in x-ray lithography apparatus, an x-ray target made of tungsten is utilized and the apparatus operated to generate the tungsten M-line, this line being at a wavelength which will be absorbed by the resist normally used in lithography. To develop the resist, which was initially designed for use in an electron beam lithography, a developing method is used in which a initial short development with a high concentration is first carried out followed by a longer, full development with a concentration which is approximately the lowest at which complete development will take place.

Abstract: An apparatus for etching one wafer while simultaneously pretreating or stripping another wafer. A module comprises a wafer etching chamber disposed within a larger chamber. The wafer etching chamber is adapted to etch a first wafer during the time that a second wafer is being pretreated in the larger chamber. When the first wafer is etched, it is transferred to the larger chamber and the pretreated second wafer is transferred to the etching chamber. During the time the second wafer is being etched the first wafer is stripped and removed from the larger chamber. A third wafer is introduced into the larger chamber for pretreating while the second wafer is being etched and the process repeated. Once a wafer enters the module for pretreating, etching and stripping, it is not exposed to the atmosphere until stripping is complete.

Abstract: An article of manufacture and a method for manufacturing a mercury vapor lamp wherein a glass mounting base is formed separately and fixed by fusing it to one end of a tubular glass envelope. The glass envelope has an evacuated bore of capillary dimension which is precisely positioned relative to the glass base and in which conductive wires are fixed at each end during the fusing process.

Abstract: A field emission gun, for either electron or positive ion emission, in which the beam current between source and sample is measured at accelerating voltage potential between two concentric shields that enclose the gun, its power supplies, and the measuring circuitry. The outer shield is directly connected to the high voltage terminal of the accelerating voltage supply while the inner shield is at the local ground reference of the emission source and associated components. The current between the concentric shields is measured, converted to a proportional voltage signal, compared with the reference voltage, and applied to a field strength controlling electrode in the vicinity of the emission source to modulate the emission and to maintain a constant beam current.

Abstract: A platen roller type printer/plotter is provided having a paper supply which is frictionally driven by the platen. The plate comprises at least three pieces which are mounted on a drive shaft with the centermost of the pieces being keyed to the shaft to rotate therewith while the other pieces of the platen are free to turn about the shaft at the same or different speeds. A paper supply is fed to the platen with a pressure roller in the middle which bears upon the central platen piece and will drive the paper straight if it is started straight. However, if the paper is put into the platen loose and skewed, driving the center platen roller pulls the paper up tight and aligns it automatically. This is due to the differential action of the different pieces of the platen since only the center piece is keyed to the shaft.An input tray which holds the paper is pivoted under the paper. Accordingly, when the paper is presented to the platen at an angle, the tray moves with the paper reducing the angle error.

Abstract: An electron multiplier, including an excitation means and collector, disposed in a high vacuum chamber and adapted to be coupled at its input to a charged particle analyzer is coupled through the vacuum chamber wall by a plurality of electrical feedthrough devices such that the excitation means is coupled to a high voltage power supply disposed outside the high vacuum chamber and the collector is coupled simultaneously through a capacitance coupling means and a resistance coupling means, both disposed within the high vacuum chamber, to an amplifier-discriminator and floating operational amplifier, respectively, both disposed outside the high vacuum chamber. The impedance offered by the capacitance coupling means is substantially lower than that offered by the resistance coupling to 10 nanosecond current pulses originating from single electron events.

Abstract: A sealing apparatus useful for sealing an injection block of gas chromatograph includes means for controlling the position of a sealing body with respect to the sealing face of such an injection block.

Abstract: There are disclosed method and apparatus for precisely aligning the pattern of an opaque mask with a previously exposed pattern on a silicon wafer. Three separate optical channels are aligned so that their axes coincide with three targets on the wafer. The objectives are also adjusted to the same vertical distance from the wafer. Thereafter, the optical channels remain fixed. The wafer is retracted a short distance and is replaced by the mask which also has three targets. The mask is then shifted to align the targets with the prealigned optical axes. When mask alignment is completed, the mask and the wafer are removed as a unit to an exposure station.

Abstract: A light chopper for chopping the monochromatic light beam of a spectrophotometer system, has a rotatable shaft driven by a synchronous motor at a frequency proportional to the power line frequency. An aperture bearing disc rotates with the shaft in relation to a photocell/detector array for generating digital timing signals for use by a microcomputer to control the tasks of the spectrophotometer system in synchronism with line frequency. The microcomputer monitors line frequency for responsively programming a programmable divider for generating an index signal for proportionally sequencing the wavelength of the monochromatic beam through a predetermined spectral range.

Abstract: A material holder is fabricated by press-fitting and welding a series of discs into an open cylinder housing. Shrinkage of the cylinder from the welding of the first disc is accommodated by selecting a smaller disc for the second press-fit. A support post is welded to the last disc and shrinkage of that disc from welding of the support post is accommodated by selecting an oversize disc for attachment to the support post. Shrinkage of the last disc also compensates for additional shrinkage of the cylinder from welding of the second disc.

Abstract: The systems comprise a transmissive shell and a mirror. The surfaces of the shell and the mirror are monocentric; that is, spherical and have the same center of curvature. Both the object and image planes are located in front of and spaced away from the transmissive shell.Single optical element systems comprise a transmissive shell with the mirror and the back surface of the shell being coincidence. These elements may be used as laser beam focusers, beam divergers and collimators.Unit relay systems for use in super accurate microcircuit printing are disclosed. Parameters are given for a monochromatic diffraction limited f/2 system in the ultraviolet.A single element monocentric catadiotric system is disclosed, which is corrected for 3rd and 5th order spherical aberration and all field aberrations except Petzval curvature. A two-element version can cover very wide fields of view with good performance at speeds as fast as f/0.6.

Abstract: A shredder includes a pair of blade assemblies operated at high speeds to receive and shred paper material, such as notes or coupons. The blades of the assemblies are disposed to contact and overlap each other. Means are provided to control the amount of overlap and loading of the blades.

Abstract: A method of depositing X-ray absorber patterns on a mask membrane to achieve minimum pattern feature dimensions less than 1 .mu.m. The membrane is covered with an ultraviolet (VU) sensitive photoresist which carries a thin metallic film. The metallic film is coated with an electron beam resist. The electron beam resist is exposed to the desired pattern by an electron beam. After development, the metal film is etched through the remaining electron beam resist. This forms a stencil overlying the lower UV photoresist layer which is then exposed by an ultraviolet or soft X-ray source. After development, an X-ray absorber, such as gold, is deposited on the membrane. The final exposure step may be done by means of a point source of radiation. The X-ray absorbers will then have sloping walls to prevent shadowing of the X-ray source.

Abstract: Method and apparatus for plasma flame-spraying coating material onto a substrate by means of passing a plasma-forming gas through a nozzle electrode, passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent, introducing spray coating material into the plasma effluent, passing the plasma effluent axially through a wall shroud extending from the exit of said nozzle electrode and forming a hot gas shroud for the plasma effluent at least within the wall shroud. .Iadd.