Abstract: Techniques are disclosed that provide a multi-mode sensor having the capability to support both passive and active operation. One embodiment provides a sensor readout device for operation with a sensor array having rows and columns of detectors. The device includes a column cell for receiving a detector output signal from a first row of a column of the sensor array, and an additional column cell. The device further includes a multiplexer configured to steer a detector output signal from a second row of the column of the sensor array to the additional column cell, thereby allowing multiple rows of the sensor array to be readout simultaneously. In some cases, the sensor array includes an active/passive dual mode central windowed area, and the multiplexer allows columns of the windowed area to be readout at two or more speeds.

Abstract: Techniques are disclosed for providing a multi-zone sensing array configured for use in a dual-mode active/passive sensor system. In some embodiments, the techniques can be used to minimize or otherwise reduce power dissipation in sensor arrays, while further providing the ability to readout the active returns rapidly. The techniques can be implemented, for example, by using the full N×M array format for target acquisition in a passive imaging mode, and then, with the aid of a gimbal for instance, place the region-of-interest in a subset of the array configured with dual-mode active/passive pixel receivers to provide three-dimensional imaging. Such techniques are capable of, for example, supporting both active and passive operating modes of a countermeasure system.

Abstract: Techniques are disclosed that provide a high-speed synchronized interface for command and control between the sensor and the laser of countermeasure systems. The techniques may be implemented, for example, in a countermeasure system configured for operation with a laser and sensor, wherein the system includes an interface with laser and sensor command control words synchronized with a master clock having an embedded System Heart Beat defining a Master Frame period, a command and control protocol for the laser and the sensor within the Master Frame period; and a T0 sensor to measure the time a laser pulse leaves the system, wherein the sensor uses the measured time as reference to set frame start and timing measurements. The system may support both active ranging and passive tracking (e.g., Master Frame period may include both passive and active sub-frames). The active ranging may include both coarse and fine resolution ranging.

Abstract: Techniques are disclosed for radiation sensors that generate current signal to provide flexible placement of one or more integration intervals between resets of an integration capacitor. With flexible timing, an embodiment of the present invention provides several modes of operation including: multiple stray light blanking interval to occur during the integration cycle; range gating for LIDAR applications; time-delay-integration (TDI) with multiple short integration periods between frame resets; and hyper-resolution gating that provides better resolution than is normally possible with a fixed gate width. Numerous variations will be apparent in light of this disclosure.

Abstract: A centroiding method is provided for an optical tracking system including a laser used for countermeasuring purposes in which a pencil thin laser beam is accurately positioned onto a target through the use of centroiding techniques for ascertaining the position not only of the target but also the laser beam, with the centroiding techniques resulting in a sub-pixel level resolution. The sub-pixel resolution permits utilization of smaller cost-effective focal plane arrays by giving the small focal plane array a resolution associated with much larger focal plane arrays.

Abstract: A centroiding method is provided for an optical tracking system including a laser used for countermeasuring purposes in which a pencil thin laser beam is accurately positioned onto a target through the use of centroiding techniques for ascertaining the position not only of the target but also the laser beam, with the centroiding techniques resulting in a sub-pixel level resolution. The sub-pixel resolution permits utilization of smaller cost-effective focal plane arrays by giving the small focal plane array a resolution associated with much larger focal plane arrays.

Abstract: A centroiding method is provided for an optical tracking system including a laser used for countermeasuring purposes in which a pencil thin laser beam is accurately positioned onto a target through the use of centroiding techniques for ascertaining the position not only of the target but also the laser beam, with the centroiding techniques resulting in a sub-pixel level resolution. The sub-pixel resolution permits utilization of smaller cost-effective focal plane arrays by giving the small focal plane array a resolution associated with much larger focal plane arrays.

Abstract: A thermally independent dedicated servo disk drive where the temperature is kept within an acceptable range and temperature gradients that can cause differential thermal expansion are eliminated to minimize off tracking due to differential thermal expansion of thermally sensitive components. A novel isolated "box within a box" architecture is utilized to provide a thermal buffer to external temperature gradients and an inner HDA support structure is coupled to an outer housing with thermally insulative isolators which prevent the conductive transfer of heat from external sources where the outer housing and isolators create a thermal buffer to shield the inner HDA support structure from external heat sources. In addition, certain heat generating components not integrated into the symmetrical thermal "box within a box" design are isolated where possible.

Abstract: An in-spindle disk drive motor incorporating a novel two-piece aluminum spindle and a method for fabricating the same. The spindle is hollow and contains a removable steel flux sleeve on which plastic permanent magnets are mounted. The spindle is mounted by means of two bearings to a non-rotating stator shaft disposed through the center of the spindle and rigidly attached to a disk drive base. One of the bearings is located in a removeable bearing sleeve at the top of the spindle and the other is located beyond the steel sleeve at the bottom end of the spindle. The aluminum spindle eliminates thermal distortion effects caused in prior art in-spindle motors by thermal expansion differences between aluminum disks and non-aluminum spindles.

Abstract: An in-spindle disk drive motor incorporating a novel two-piece aluminum spindle and a method for fabricating the same. The spindle is hollow and contains a removable steel flux sleeve on which plastic permanent magnets are mounted. The spindle is mounted by means of two bearings to a non-rotating stator shaft disposed through the center of the spindle and rigidly attached to a disk drive base. One of the bearings is located in a removable bearing sleeve at the top of the spindle and the other is located beyond the steel sleeve at the bottom end of the spindle. The aluminum spindle eliminates thermal distortion effects caused in prior art in spindle motors by thermal expansion differences between aluminum disks and non-aluminum spindles.

Abstract: An in-spindle disk drive motor incorporating a novel two-piece aluminum spindle and a method for fabricating the same. The spindle is hollow and contains a removable steel flux sleeve on which plastic permanent magnets are mounted. The spindle is mounted by means of two bearings to a non-rotating stator shaft disposed through the center of the spindle and rigidly attached to a disk drive base. One of the bearings is located in a removeable bearing sleeve at the top of the spindle and the other is located beyond the steel sleeve at the bottom end of the spindle. The aluminum spindle eliminates thermal distortion effects caused in prior art in-spindle motors by thermal expansion differences between aluminum disks and non-aluminum spindles.

Abstract: A Winchester disc spindle construction provides a spindle motor coil wound around laminated formed annular plates and having lead wires extending through a central stationary shaft. Surrounding a spindle coil is a cylinder having a pocket for arcuate permanent magnets. The discs are fixed to and rotated by the cylinder. Relatively large bearings support the cylinder concentric with the shaft and give increased strength to the structure, permitting more discs to be supported in equivalent space, as compared with prior structures. The arms carrying the read-write heads are mounted on a stack of spaced-apart arms pivotted at a distance from the discs so that the heads move along a shallow arc to reduce skewing of the heads relative to the recording tracks of the discs.

Abstract: In a Winchester hard disk drive assembly having at least one disk rotatably disposed on a cylindrical spindle, the improvement compromising spacer means interposed between the inner diameter of said at least one disk and the outer diameter of said cylindrical spindle, said spacer means defining a clearance between said at least one disk and said spindle and adhesive means for adhesively securing said spacer means between said spindle, and said at least one disk, whereby a substantially uniform and contiguous clearance is maintained about the circumference of the spindle upon thermally induced differential expansion of the disk, and whereby said disk will be substantially prevented from abutting the outer circumferential wall of the spindle.

Abstract: To overcome problems of precise permanent location of aluminum Winchester discs relative to their steel drive spindle during temperature variations, in one form of the invention a plastic washer is placed between the disc and the underlying flange of the spindle. The washer maintains contact by static friction without slippage but is compliant with shear forces occasioned by temperature changes and, by reason of its elasticity, returns the members to their initial position when the original temperature is restored. In a second form of the invention, the steel flange is grooved to form a thin ring and the ring is slotted to provide flexible fingers on which the disc rests. These fingers likewise maintain permanent contact with the disc and are likewise compliant with changes in relative position occasioned by temperature variations, restoring the disc to original position relative to the spindle.

Abstract: A latch interlock mechanism for an access door through which a magnetic disc cartridge is inserted into a disc-drive assembly. The interlock prevents the access door from being opened while a magnetic head is being loaded or is loaded onto the disc. A pivot latch cooperating with the access door is coupled to a rigid rod which moves along its length. The rod is coupled to the head lift mechanism which loads and unloads the magnetic heads. The push rod is coupled to the pivot latch by means of a coil spring co-axially mounted on the push rod with the end of the spring furthest from the first end of the push rod fixedly attached to the push rod. The other end of the coil spring interacts with the pivot latch. The second end of the push rod is coupled to an actuator element of the head lift mechanism by means of a pivoted lever. During a head load cycle, the movement of the actuator element is coupled to the push rod to engage the latch before the heads are lowered onto the surfaces of the disc.

Abstract: An actuator for linearly moving magnetic heads in which an open-ended carriage assembly extends down both sides of the magnet structure in order to provide a much shorter actuator assembly than is typical is described. The loading mechanism is not mounted upon the carriage assembly, thereby allowing the actuator to have a higher resonant frequency than those actuators which carry a more complex structure on the carriage assembly. The magnet structure is in the shape of an E with the motor coil, which is mounted across the open end of the carriage assembly, moving along this center section of the magnet structure. Alignment pins located at the other end of the carriage assembly allow the magnetic head arms to be mounted and aligned quickly and with precision.

Abstract: A mechanism for loading and unloading magnetic heads from the surfaces of a magnetic disc is described. The invention uses lift rods which are pivoted about a portion of their length and have offset sections which cooperate with the head lift arms or mounting flexures upon which the magnetic heads are mounted. The lift rods are controlled through other offset sections located along their lengths. These other offset sections, in the preferred embodiment, are pressed against conical surfaces which are oriented so that the axes of the surfaces are in a direction perpendicular to the pivoting axes of the lift rods. Movement of the conical surfaces toward and away from the pivoting axes of the lift rods imparts an arcuate motion to the offset sections of the lift rods with which they cooperate, and this correspondingly produces arcuate motions in the offset sections which cooperate with the head mounting flexures. By this motion, the magnetic heads are gently loaded or unloaded onto or from a magnetic disc.