Memorex Corporation

Insite Peripherals

Sperry Rand Corporation

Unisys Corporation

Edc Biosystems, Inc.

Sperry Corporation

Andrew M Rose

Alton B Otis, Jr

Roger O Williams

Frank J Sordello

James Chiao

Stephen Paul Williams

Jimmy D Godwin

Mark E Strysko

James Joseph Touchton

Nicholas M Warner

Michael L Ivers

Michael James Forbush

Michael R Van Tuyl

Humphrey W Chow

Michael J Herrmann

David G McLaughlin

A liquid dispensing apparatus for dispensing droplets of a liquid, and methods for measuring various fluid parameters of the liquid are described. The liquid dispensing apparatus comprises a container having a chamber for holding a liquid. An orifice is positioned at an end of the chamber for dispensing droplets of the liquid, the orifice being configured to retain the liquid in the container if the container is positioned with the orifice facing in a downward direction. An acoustic transducer means is at least partially positioned in the chamber for periodically propagating a focused acoustic beam toward the orifice and through at least some of the liquid while the liquid is contained in the chamber, with the focused acoustic beam being capable of causing a droplet of the liquid to be ejected from the orifice when a free surface of the liquid is within the depth of field of the acoustic transducer means. Fluid parameters that can be measured include the sound velocity in the liquid, liquid level and liquid concentration, liquid acoustic impedance, liquid density and ultrasonic viscosity.

Acoustic liquid dispensing apparatus

The present invention comprises a noncontact method for measuring viscosity and/or surface tension information of a liquid in a liquid containment structure. The steps of the method include exciting a surface of the liquid with an excitation burst of acoustic energy that causes the surface to oscillate; generating a positional data set comprised of a plurality of positional measurements related to the detected position of the surface at a plurality of times after the surface is excited; generating a frequency domain data set from the positional data set, the amplitude spectrum of the frequency domain data set comprising information about the oscillation frequency of at least one vibrational mode of the of the surface as it oscillates; and processing the frequency domain data set and/or the positional data set to yield information about the surface tension and/or viscosity of the liquid. A Fast Fourier Transform technique may be used in generating the frequency domain data set.

Acoustic method for determining the viscosity and/or surface tension of a liquid

A dual magnetic head having a first magnetic core for reading and writing very high track density floppy disks and a second magnetic core for reading and writing conventional track density floppy disks. Neither the first nor the second magnetic cores require the trim erase elements associated with prior art magnetic cores for use with floppy disks. When writing on conventional track density floppy disks, separation between data tracks is achieved by erasing a circular region on a first rotation of the floppy disk, erasing a second region, separated from the first region by a small gap, on a second rotation of the floppy disk, and writing data during a third rotation of the floppy disk centered about the small gap. With very high density floppy disks, data is written directly between optical servo tracks on the floppy disk without use of the two erase steps.

Dual magnetic head and method for writing on very high track density and

A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions. The innermost tracks contain redundant copies of a disk mapping table that comprises data for a media type code, a sector size code, a sector interleave code, a total track count, a reassignment area starting address, a data area starting address, a total sector count, an update count, and a reassignment table having at least room for 250 entries of three bytes each.

Very high-density diskette format method and computer-implemented process

Very high-density diskette format method and computer implemented process

A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of optical positioning tracks on at least one of said sides of said media, and a media type code optically embossed on at least one of said sides of said media. The media type code contains information about the physical properties of the particular diskette that will allow a disk drive unit to auto-configure itself to allow optimum data communication and performance.

Disk drive for communicating with removable media that include media

In a disk drive servo, position slope is adjusted automatically, by referencing on the amplitude of position signals at the 'half-track point'.

Apparatus for adjustment of position slope for servo

Magnetically indelible media type identification system

Adjustment of position slope for disk drive servo using half-track point

A method for measuring bit shift and other characteristics indicative of the performance of a magnetic storage system, particularly for a system employing a thin-film magnetic head. In a preferred embodiment, complementary patterns are written many times around a circular track of a magnetic disk, each pattern including relatively closely spaced magnetic transitions as well as relatively widely spaced magnetic transitions. The relatively widely spaced transitions are chosen so as to be substantially unaffected by any other transitions. Measurements are made with reference to these widely spaced transitions and averaged for the many patterns recorded in the track so as to rapidly provide highly reliable measurements indicative of system performance.

Method for testing components of a magnetic storage system

A method for measuring bit shift, timing asymmetry and other characteristics indicative of the performance of a magnetic storage system, particularly for a system employing a thin-film magnetic head. In a preferred embodiment, complementary patterns are written many times around a circular track of a magnetic disk, each pattern including relatively closely spaced magnetic transitions as well as relatively widely spaced magnetic transitions. The relatively widely spaced transitions are chosen so as to be substantially unaffected by any other transitions. Measurements are made with reference to these widely spaced transitions and averaged for the many patterns recorded in the track so as to rapidly provide highly reliable measurements indicative of system performance.

Method for measuring timing asymmetry in a magnetic storage system

A disk storage system is disclosed comprising a rotatable disk, a cooperating magnetic head, positioning apparatus for positioning the head at different radial positions of the disk for reading and/or writing data on the disk, a baseplate for supporting the above, and control circuitry for preventing oscillation build-up in the baseplate from deleteriously interfering with system performance. The control circuitry is constructed and arranged to control the timing of head positioning operations so as to inhibit the reinforcement of baseplate oscillations.

Disk accessing circuitry

An apparatus to improve the positioning accuracy of an actuator in a disc system. The apparatus provides for accelerating and braking the actuator at appropriate times during positioning operations in order to accurately position the actuator at a selected track on the disc. In addition, in order to maintain positioning accuracy in the presence of run-out, provision is made for detecting the occurrence of run-out by comparing positioning accuracy at spaced time intervals and blocking actuator braking at those times when it would be counter-productive to positioning accuracy.

Method and apparatus to improve the positioning accuracy of a tracking

An access control system for controlling the velocity of a head assembly in a disc drive has a digital difference counter, to note the number of tracks to be traversed, a ROM to output two values of velocity: One value corresponding to the present remaining number of tracks and another value corresponding to the remaining number of tracks minus one. An intergrator generates a signal between each track crossing. An oscillator produces a plurality of signals per track. The signals from the oscillator are compared to the signal from the integrator by a comparator. The output of the comparator is a series of pulses, all of which have the same frequency, but with different duty cycles. This series of pulses is used by the ROM to modulate its output such that one value of velocity is outputted when the pulse is 'high' and another value of velocity is outputted when the pulse is 'low'. The signal from the ROM is converted to an analogue signal and is used to control the head assembly.

Velocity control system for a data storage apparatus

A servo system in a disc drive for accessing and maintaining selected data tracks on a stack of discs has a first continuous position signal derived from a pre-recorded surface and a second position signal derived from servo information in sectors of the other discs. The first and second position signals are combined to form a hybrid signal to control the actuators. The hybrid signal is the second signal when the second signal is generated. When the second signal is not generated, the hybrid signal is a modified first signal plus the last known second signal. The modified first signal is the difference between the first signal presently generated and the first signal generated when the second signal was last generated.

Growing community of inventors

Mountain View, CA, United States of America

Andrew M Rose