Abstract: A timer circuit provides a wide range of precise and substantially accurate time intervals. The timer circuit includes a ramp generator circuit having a first input for receiving an input signal to start a ramp signal, a second input for receiving a ramp timing conrol signal, and an output for providing a ramp signal. A comparator has a first input coupled to the output of the ramp generator, a second input coupled to a reference voltage source, and an output for providing an end ramp signal. A counter circuit has a first input for receiving the end ramp signal to begin counting, a second input for receiving a counter timing control signal, and an output for providing a terminal count signal. The end ramp signal and the terminal count signal are combined in an AND gate to provide a signal that is delayed by a predetermined amount from the input signal.

Abstract: A drop-on-demand ink jet has an ink chamber coupled to a source of ink, and an ink drop orifice with an outlet. An acoustic driver produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop orifice and outlet. The size of the ink drops may be varied, such as by driving the acoustic driver with varying drive signals, preferably comprising individual or combinations of plural bipolar drive pulses. The ink jet printer of the present invention may be used to print with a wide variety of inks, including phase change inks.

Abstract: An electro-optical transducer module assembly has a substrate on which is secured a guided-wave transducer having an optical waveguide and electrode structure formed on one surface thereof with the waveguide surface in a facing relationship with the substrate. Spacers are provided to position the transducer above the substrate surface and means are provided to electrically connect the electrode structure with the substrate. Optical waveguides are affixed to the substrate adjacent to the transducer for coupling an optical signal into and out of the transducer.

Abstract: A method and apparatus prevents unwanted synchronization from obstructing a data acquisition instrument operator's view of N multiplexed signals synchronized to a high speed system clock being used to trigger an instrument through a prescaler with a fixed prescaling factor M, where N and M are related by a common factor. During a time while the instrument, for example, an oscilloscope, is ignoring trigger input information, a desynchronizing signal is applied to the prescaler, causing it to miss a random number of counts or causing it to count incorrectly. Thus, when the oscilloscope resumes triggering it is likely to be synchronized to a different combination of the multiplexed signals. This technique can be applied to individual data points or to records containing a number of data points.

Abstract: An automatic anomalous event detection method uses a pair of counters to count the occurrence of main triggers simultaneously with the occurrence of advanced triggers indicative of anomalous events as defined by an operator. The anomalous events may be defined as either time or voltage qualified events that occur at a much lower rate than the repetition rate of an input analog signal being measured. When the main trigger counter reaches a maximum count, the count of the advanced trigger counter is compared with a range greater than zero to less than the maximum count modified by an operator specified divider. If the advance trigger count is within the range, then an anomalous event is detected and the next advanced trigger signal causes a portion of the input analog signal to be acquired for storage in a waveform memory and subsequent display of the anomalous event.

Abstract: A method and apparatus performs time-interval to voltage conversion immediately and continuously allowing timing variations to be viewed and correlated with other voltage signals displayed on an oscilloscope. A calibration output assists in calibrating the vertical gain and offset of the oscilloscope. An automatic setup software routine finds suitable resolution and offset settings. The method includes the steps of selecting the type of time-interval to be measured, scaling the counting of a clock signal appropriately, offsetting the counting means as desired, counting the number of clock signals that occur during every selected time-interval, limiting the counted results to a preselected range, and converting the counted results to an analog voltage for display by an oscilloscope.

Abstract: The present invention is a method and an electrical circuit (28 and 50) for effectively eliminating the effects of time jitter caused by metastable states by rejecting measurements made under timing conditions that could lead to the development of metastable states. In a preferred embodiment, the circuit of the invention effectively eliminates time jitter caused by metastable states in digital oscilloscope circuitry by determining in advance the timing conditions that can lead to such jitter and detecting whenever the transitions of trigger and trigger hold-off signals meet such timing conditions. The circuit then generates a "possible metastable" signal that can be used by the oscilloscope circuitry, or by the controlling software, to reject any measurement made under those timing conditions.

Abstract: A compact ink jet printer is described utilizing a small drum for carrying a sheet of record medium during the printing operation. In one embodiment, the drum has an exterior surface with a high coefficient of friction with a contact roller retaining the record medium against the drum as the drum is rotated. Printing is accomplished as by jetting ink from an ink jet print head onto the medium while the medium is backed up by a fixed platen. A fusing mechanism may be utilized to flatten ink drops on the printed medium. A drive mechanism for an ink jet printer may include a stepper motor coupled by timing belt sprockets and a timing belt to the drum of the printer. These components may be selected such that the drum is incremented a multiple of a pixel height during each step of the stepper motor. The record medium may also be clamped to a drum by a clamping mechanism and rotated through plural revolutions of the drum during respective printing and fusing steps.

Abstract: A dual output balun distributes substantially all of the available power in a single ended input signal applied thereto (less small parasitic losses) equally to two or more pairs of push-pull output terminals (or vice versa).

Abstract: An improved marker and cursor system for spectral waveform measurement permits the operator to link or unlink a cursor and a marker, allowing them to be used separately or in coordination to make bandwidth measurements. A second reference marker permits measurement of the frequency and amplitude differneces between it and the marker at the same time that the marker is being used control the linked cursor. The cursor can be fixed or linked in a constant positive or negative delta-amplitude relationship to the marker. The points on the cursor where the cursor and spectral waveform intersect are intensified for identification and a readout is provided of the difference in frequency values between these points. Measurements continue even during unstable conditions of the instrument or spectral waveform and fluctuations show up as only minor movements of the intensified points along the cursor.

Abstract: Print heads are formed with spaced subheads having nozzles such that all of the lines or pixel rows on a print medium such as a sheet of paper are printed by scanning of the print head along the face of the sheet. The head structures include three subheads, each having nozzles for printing one or more adjacent lines with the subheads being spaced the same number of lines apart as the number of lines each prints; and three subheads spaced the equivalent of seven lines apart, each subhead having three nozzles spaced at the equivalent of alternate lines. The heads are advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end.

Abstract: A method and apparatus for determining the internal state of a processor without disturbing the operational environment of the processor employs a two phase process. In the first phase, external signals produced by the processor in the execution of a known program are monitored and recorded for subsequent analysis. In the second phase, the recorded information is analyzed in the light of the known characteristic of the processor, the program it was executing, and the signals recorded during the first phase. The internal state of the processor is thereby determined after the execution of each instruction. In addition, provisions are made for the specification of breakpoints, and the examination of simulated status of the processor on the occurrence of the breakpoints.

Abstract: A sequence of n sample values occurring during a recording interval is processed by determining which of the sample values is the smallest and which of them is the largest. The smallest sample value is loaded into one of first and second memory portions in dependence upon whether the smallest value occurred before or after the largest sample value, and the largest sample value is loaded into the other of the first and second memory portions. In this fashion, the order of the smallest and largest sample values is preserved.

Abstract: A method for producing a light-transmissive printed substrate is provided. The substrate is printed with a predetermined pattern of a light-transmissive phase change ink which initially transmits light in a non-rectilinear path. When the pattern of solidified phase change ink is subsequently reoriented to form an ink layer of substantially uniform thickness, a printed image layer is formed which will transmit light in a substantially rectilinear path and is suitable for overhead projection.In some instances the adhesion between the ink image layer and the substrate is not as high as is desired. This problem can result in delamination of the ink from the film under certain conditions. In order to overcome this problem, an intermediate optically clear adhesion promoting layer is introduced between the light-transmissive phase change ink and the base substrate.

Abstract: A damped cradle for a pressure sensitive device is constructed in a unitary form. The cradle has a base that is attached to a substrate. Extending upward from the base are side arms with pairs of spring, or compliant, tips that contact the sides of the pressure sensitive device. Also extending upward from the base over the top of the pressure sensitive device are spring arms with compliant tips that contact the top surface of the pressure sensitive device in non-active areas. Vibrational forces in lateral (X-Y plane) directions are damped by friction between the bottom of the pressure sensitive device and the surface of the substrate, and vibration motion in the vertical, or Z, direction is stopped by enough spring force to overcome the maximum acceleration force the crystal mass encompasses for a given application. The spring forces of the spring tips and spring arms are balanced to produce a near zero pressure on the pressure sensitive device in both static and dynamic modes.

Abstract: A frame buffer memory controller allows rapid image updating while maintaining screen refresh data flow rate. One frame buffer memory controller controls one or more pixel depth columns comprising one or more frame buffer memory chips per pixel. Each frame buffer memory controller listens on a display processor bus for read, write or read-modify-write commands addressed to a pixel, or memory chip, under its control. Such commands, along with the associated addresses and data, are stored in a first-in, first-out (FIFO) buffer for execution during the first free memory cycle.

Abstract: A detection circuit (30, 32) for carrying out a rapid search technique for locating the position of a stylus (12) relative to a display screen (10). A microprocessor (34) and related components select a group of light detectors (20, 28) that are positioned near the display screen (10). The summed output current of the selected group of detectors (20, 28) is monitored to determine whether the output of any detector in the selected group is reduced because of the presence of a stylus (12). Whenever the selected group shows such reduction in output current, that selected groups is divided into two subgroups. The subgroup having reduced current output due to the presence of the stylus (12) is further divided until the particular detector(s) having reduced output current is found, the position of the detector is correlated to the location of the stylus (12) relative to the screen (10).

Abstract: An acousto-optic modulator for use in an optical time domain reflectometer to test multimode optical fibers has an active material, such as AS-Se-Ge or As.sub.2 S.sub.3 glass, that has a high figure of merit with a low insertion loss. The transducer for the modulator is configured to have a height that encompasses the multimode beam diameter at the optical wavelength, and a length that is consistent with a theoretical lower limit that is a function of the acoustic and optical wavelengths. Sufficient RF power is applied to the modulator to produce an angular efficiency, or optical throughput, that is sufficient to meet the specifications for the optical time domain reflectometer.

Abstract: As frequency spectra are produced continuously at a speed that is too fast for realtime display, they are accumulated in a memory. After a block of these frequency spectra have been accumulated, they are read back from the memory and displayed on a display device that permits the display of multiple frequency spectra along a time axis. Markers allow delta-time measurements to be made between different spectra in the display. Continuous storage into a circular memory can be stopped and the display of the accumulated frequency spectra started by the detection of the occurrence of a pre-defined spectra event.

Abstract: An apparatus for counting the number of times that each of a large number of digital data patterns are present on a set of signal lines comprises a plurality of random access memories (RAMs) and a feedback means, arranged to form an array of linear feedback shift registers. The data to be analyzed is applied to the address inputs of the RAMs where it selects one of the linear feedback shift registers in the array. A data-valid signal associated with this data causes the selected linear feedback shift register to increment (or decrement) in its pseudo-random count. After the analysis period is over, the value at each address is read out and translated using a lookup table or other translating means from the pseudo-random code of the linear feedback shift register into a meaningful number. This result may then be displayed; for example, in a histogram. An improved feedback path for the linear feedback shift register avoids hang-up states and the need for initialization.