Abstract: Method and apparatus is described for controlling the formation and shape droplets in an ink jet stream. The continuous portion of the stream is illuminated with a radiant energy source such as a laser. The surface wave profile produced by illuminating the stream is sensed to provide the fundamental and harmonic frequency components thereof. A perturbation drive signal, the amplitude and relative phase of which is a function of the sensed frequency components, is provided for controlling the formation and shape of the droplets.

Abstract: A pre-aimed nozzle device comprises a nozzle block with an orifice wafer attached thereto. The nozzle block has an aiming surface. The orifice wafer comprises an annular orifice element retained in the body of the wafer in a manner whereby the orifice element and wafer are bonded to the nozzle block with the opening of the orifice element perpendicular to the aiming surface. The orifice wafer is made by encapsulating a straight section of glass tubing in a block of ceramic. The block is machined with precision external location surfaces. A groove is machined into the block with internal location surfaces parallel with the external location surfaces. After potting of the tube in the groove with solder glass, the wafer block is cut along planes perpendicular to the external location surfaces to obtain annular orifice elements precisely aimed relative to the wafer body.

Abstract: A data transmitting and receiving system in which data is transmitted by varying the phase and amplitude of a carrier, including a receiver which detects the data in a received signal while reducing the effects of noise components which alter the phase and amplitude of the received signal. An in-phase component and a quadrature component are derived from the received signal and are then rotated an angular amount which is a function of an estimated value of the phase error in the received signal. The rotated components are then compared with two sets of reference coordinates for selecting a pair of reference coordinates which have values closest to the values of the rotated in-phase and quadrature components, respectively. The estimated value of the phase error is derived as a trigonometric function of the rotated components and selected reference coordinates. The selected reference coordinates are indicative of the transmitted data.

Abstract: A jet printer includes a nozzle plate having at least two rows of nozzles, with the nozzles in one row being laterally staggered with respect to the nozzles in another row. The jets emanating from the respective rows of nozzles are directed in non-parallel trajectories to form at least a portion of a single line of dots at a time on a printing medium, with the jets from a given row forming non-adjacent dots on the printing medium. In practice, the nozzle plate is comprised of a semiconductor substrate, for example silicon, with the exit aperture of each of the nozzles in at least one row being axially misaligned with respect to the longitudinal center axis of their respective entrance apertures, resulting in a non-normal jet trajectory with respect to the plane of the nozzle plate.

Abstract: In an ink jet printing system, a single nozzle or an array of nozzles are etched in a semiconductor material such as silicon. Each nozzle has polygonal or N-sided entrance and exit apertures of different cross-sectional area. Preferably, the nozzle is in the shape of a truncated pyramid with the entrance and exit apertures being substantially square in cross-section. The corners of the apertures and wall interfaces may be rounded to reduce stress concentrations.

Abstract: An operating system authenticator for determining if an operating system being loaded in a computer is valid. A user's identification code or secret key which is unique to the operating system, and a verifier value which is a predetermined function of a valid operating system and the identification code are respectively stored. A hash function, which is a function of the operating system being loaded and the identification code, is generated by the authenticator. After the operating system is loaded, the hash function is used as an authenticating value and compared with the verifier value for determining the authenticity of the loaded operating system.

Abstract: A system for obtaining N slices of substantially uniform thickness from a solid to provide a batch having a desired weight, where N is an integer which may have a value between predefined limits. A partial batch weight is taken in response to weighing a number of slices less than N. A terminal value of N is estimated on the basis of the number of slices in the partial batch and the ratio of the desired batch weight and the partial batch weight. A predicted terminal deviation from the desired batch weight is calculated based on the partial batch weight and the ratio of the estimated value of N and the number of slices in the partial batch. In one embodiment the feed rate of the solid into a slicing device, and accordingly the slice thickness and terminal batch weight, is controlled as a function of the value of the predicted terminal deviation.

Abstract: A scanner transfers information in the form of magnetic characters to a soft magnetic film, and subsequently transfers the information to a storage medium, such as disc, tape, or the like. Use of amorphous and other bubble material is suggested. A bias field is coupled through the magnetic characters to the material in which bubbles are generated and transported.

Abstract: A closed loop communication system in which the terminals are grouped into priority classes. Any terminal can seize a free channel if certain priority conditions exist. A channel (frame) is always preceded by a header comprising a priority request field and a priority grant field. The request field has n bits assigned to the n priority classes; a terminal requiring service sets that bit to "1" which corresponds to its class. Thus, the controller receives a compiled overall request and inserts, for the next cycle, into the grant field an indication as to which priority class or classes are now allowed access to the channel. This is accomplished by shifting the contents of the request field to the grant field. A terminal can only seize the channel if its priority class is allowed for that cycle by the grant field, and if the channel is still free.

Abstract: A charging electrode array for droplets formed from a plurality of liquid streams is formed in a silicon substrate. The substrate also has an FET shift register and FET latch circuits formed therein to supply signals to the charging electrodes, which are formed by diffusing a dopant into at least a selected portion of the wall of each of a plurality of passages in the substrate.

Abstract: In a delta modulator a sequence of code symbols are generated which are indicative of increments of signal level, with each code symbol being determined in accordance with the difference in signal level between an input signal and a prediction signal which is a representation of the input signal. A sequence of the generated code symbols are stored, including the most recent code symbol and a preceding number of code symbols, with the pattern of code symbols at any instant defining a state of signal activity. There is a table of delta increments, a table of threshold values, and a digital gain logic network, all of which provide signal outputs which are controlled by the state of signal activity represented by the stored code signal pattern. The signal output from the delta table and the threshold table are modified an amount determined by the value of the signal output from the digital gain logic network.

Abstract: A digital phase filter including two decision filters connected in cascade or parallel for minimizing the noise components in a received phase modulated digital signal. The first decision filter cancels the residual noise component representing the phase intercept component and the phase shift component introduced by frequency shift, and the second decision filter minimizes the random noise component representing phase jitter and white noise.

Abstract: This is a communication loop system having a bidirectional transmission capability between terminals. The system is comprised of switching units which allow isolation of a loop segment and the establishment of an operable folded loop for the remaining non-isolated loop portions of the system. In addition, the communication loop system comprises devices for enabling synchronous switchover operation during reconfiguration of the loop. This synchronous switchover insures that no data stream interruption or disturbance occurs for the units or terminals not attached to the disconnected loop segment.