Abstract: The present disclosure relates to a method for regulating a pump power of an optical amplifier, where a multiplexed broadband optical signal having several channels is amplified at a certain gain value while a change in power is detected at the input or output of the amplifier. A new pump power is calculated and adjusted based on a previously provided stable gain state of the optical amplifier after detecting the change in power such that deviations of the gain value remain minimal as planned temporary interface transients during a specific interval. The new pump power is thus calculated very accurately and quickly according to a model that takes into account the actual gain value, the wavelength dependence of active channels, aging effects, and non-linear amplification effects.

Abstract: In an optical amplifier of the invention, a first variable optical attenuator is provided between a fore-stage optical amplification unit and a post-stage optical amplification unit, and a second variable optical attenuator is also provided on the output side of the post-stage optical amplification unit. When a signal light input level of a WDM light inputted to an input port is lower than a base point level, an attenuation amount of the first variable optical attenuator is not increased (basically minimized), and the control which increases the attenuation amount of the second variable optical attenuator is performed corresponding to the increase in signal light input level. On the other hand, when the signal light input level is higher than the base point level, the attenuation amounts of both the first variable optical attenuator and the second variable optical attenuator are controlled according to the signal light input level.

Abstract: A system includes a pulse reshaper for reshaping and re-amplifying optical signals in a communications network. In one embodiment, a vertical cavity semiconductor optical amplifier (VCSOA) device, comprising dual mode reflectors optically cooperating at each of an input signal wavelength (?s) and an offset wavelength (?c) proximate the input signal wavelength (?s) to provide thereby non-linear amplification of input signal (?s).

Abstract: The objectives of the present invention are to prevent or inhibit the deterioration effects such as light transmission, diffraction, reflection, spectrum generation, and interference, and these combinations, and by so doing, decrease the frequency of maintenance operations such as window replacement and to reduce the costs for such operations. This invention is characterized by steps of creating a near vacuum zone with a presence of active energy to excite an oxidation reaction of carbon wherein the near vacuum zone faces the lighting surfaces of the optical system; generating negative ions or radicals in the near vacuum zone such as unstable chemical seeds containing oxygen atoms, such as OH radicals, OH ions, ozone, O2 ions, O-radicals; and removing or reducing the accumulated carbon which deposits on the lighting surface, by reacting the deposited carbon with the negative ions or radicals.

Abstract: By adding perspective information in addition to binocular parallax, the invention provides a three-dimensional medical imaging apparatus that allows surgery to be performed with a more natural three-dimensional view, similar to that achieved with the naked eye. The three-dimensional medical imaging apparatus includes an image-acquisition optical system and an imaging device for acquiring three-dimensional images of a subject. The image-acquisition optical system includes an objective optical system for forming an image of the subject at an image-forming plane, and an entrance pupil position of the image-acquisition optical system is disposed between the objective optical system and the subject.

Abstract: A projection screen for displaying an image projected as a combination of primary colors, the projection screen comprising a coating applied to a substrate. The coating contains one or more pigments whose colors correspond to the primary colors.

Abstract: A perforate projection screen for movies, planetariums and the like having inconspicuous seams and uniform reflectivity throughout its visible surface. The screen is made from a plurality of perforate panels and is mounted, when in use, with a dark non-reflective chamber behind the screen. Any overlapped areas of the panels and any frame members or other objects, in close proximity to the back of the panels are covered with a black velour type material to prevent light reflection from panel holes where objects are in close proximity to the back of the panel. The edges of adjacent panels overlap to form seams with the overlapped edges of the panels being crimped to form recesses to receive the overlapping edge strip of an adjacent panel, thereby hiding the overlapping panel edge to reduce shadow lines and make the panel edges inconspicuous to viewers.

Abstract: The present invention relates to projection films and methods of making the same. In particular, the present invention relates to a projection film whereby the microspheres exhibit improved alignment on the light exit surface and have alignment on the light entrance surface that varies according to the individual microsphere diameter. In another embodiment, the present invention relates to a projection film that has the attributes of variable gain within the single projection film. In another embodiment, the present invention relates to an exposed microsphere projection film construction that provides modification of the head-on and angular pattern of light transmission (gain).

Abstract: An imaging material has been developed which provides improved image contrast, increased gain and increased viewing angle. A method for production of the screen element is also described. The imaging material of the invention includes a refractive optical element which redirects incident light along a desired axis, a light transmissive focusing region which diffuses the light along the desired axis, and a controlled light-transmissive region which controls backscatter and increases contrast. The refractive optical element desirably includes an active surface such as a lenticular array embossed thereon which serves to redirect incident light as desired. The focusing region desirably is made of a matrix material having a refractive index n1, having dispersed throughout the matrix asymmetric micro-bodies that have a refractive index n2 different from n1. The controlled light-transmissive region may desirably comprise an alternating black stripe and transparent region.

Abstract: By using high and low refractive index materials, a planarized reflective-refractive Fresnel lens and a planarized refractive lenticular lens can be created. These flat screen components eliminate the need for an air-gap, thus reducing the screen thickness. Additionally, this allows for the screen to be manufactured on a roll-to-roll process that can significantly reduce the screen cost. By adding the capability of planarizing the elements, they can be combined in a final structure on a roll-to-roll process. Since the Fresnel lens can be combined with the lenticular lens before exposure of the black stripe region, the exposure of the black stripe region can account for any deviation from true collimation or non-normal angle of incidence of the light path in the projection system design.

Abstract: A projection type screen comprises a reflection surface array and a lenticular sheet. In the reflection surface array, a plurality of reflection surfaces is located along a horizontal direction. Each reflection surface has a mirror reflectivity of which section along the horizontal direction is quadratic curve shape. The lenticular sheet is located at an incident side of a projection light for the reflection surface array. The lenticular sheet has diffusivity along a vertical direction.

Abstract: The present invention provides a Fresnel lens sheet that scarcely makes the projected image distorted, and others. The Fresnel lens sheet has a plurality of unit total reflection Fresnel lenses arranged on the light-entering side, each unit lens having a light-entering surface and a total reflection surface that totally reflects a part of or all of the imaging light that has passed through the light-entering surface to deflect the light in the desired direction. This Fresnel lens sheet is formed so that it fulfills the relationship H1×H1/(10×E1×T1×T1)?3L/2000, where H1 represents the length (cm) in the vertical direction of the Fresnel lens sheet; L1, the length (cm) in the horizontal direction of the Fresnel lens sheet; T1, the thickness (cm) of the Fresnel lens sheet; and E1, the modulus of elasticity (kgf/cm2) of the Fresnel lens sheet.

Abstract: In a diffusion sheet 101, a plurality of approximately trapezoidal columnar unit lens portions 11 are disposed such that the long-axis directions thereof are in parallel with each other, and all the surfaces of the unit lens portions, which correspond to the long bottom segments 112 of the approximately trapezoidal sections of the unit lens portions 11 are disposed on a light-incident-side flat surface. Further, light absorbing portions 12 are disposed in the grooves between adjacent unit lens portions 11 to absorb and/or shield external light incident from a light outgoing side. In the diffusion sheet 101 arranged as described above, light incident on the unit lens portions 11 from a light incident side is totally reflected on the surfaces corresponding to the side segments 111 of the approximately trapezoidal sections vertical to the long-axis direction of the unit lens portions and outgoes from the light outgoing side.

Abstract: Devices of information displays, in particular liquid crystal displays, which can be utilized in indication devices for various purposes. Liquid crystal displays, according to this disclosure, contain at least one layer of liquid crystal placed between two plates, on each plate there has been formed or applied at least one electrode or a system of electrodes, or an active matrix, and at least one layer of polarizer; while at least one polarizing layer is an E-type polarizer and at least one polarizing layer is an O-type polarizer.

Abstract: An optical system includes at least one cubic crystalline optical element aligned along an optical axis, the at least one cubic crystalline optical element being birefringent and imparting retardance on a beam of light propagating through the optical system along the optical axis, and polarization rotation optics inserted along the optical axis and selected to rotate the polarization of the beam of light to at least partially reduce the retardance.

Abstract: Disclosed is a compact zoom lens system having a image stabilizing function. This zoom lens system is provided with a plurality of lens units of which the interval between adjacent ones is changed during zooming. Shake correction is effected by a part of a lens unit of negative optical power of the plurality of lens units. Specifically, the lens unit of negative optical power is comprised of two lens components of negative optical power, and one of these two lens components is moved so as to have a component in a direction perpendicular to an optical axis to thereby change the imaging position of the zoom lens system.

Abstract: A diffractive optical element has a support and a plurality of diffraction structures. The latter are applied on the support and are binary blazed by being split into substructures so that the aspect ratio of the substructures varies locally within an individual diffraction structure. One or more substructures with a large aspect ratio inside an individual diffraction structure are replaced by at least one substitute structure whose aspect ratio is less than that of the replaced substructures.

Abstract: A spectral purity filter includes an aperture, the aperture having a diameter, wherein the spectral purity filter is configured to enhance the spectral purity of a radiation beam by reflecting radiation of a first wavelength and allowing at least a portion of radiation of a second wavelength to transmit through the aperture, the first wavelength being larger than the second wavelength. The spectral purity filter may be used to improve the spectral purity of an Extreme Ultra-Violet (EUV) radiation beam.

Abstract: Fluidic adaptive lens devices, and systems employing such lens devices, along with methods of fabricating and operating such lens devices, are disclosed. In one embodiment, a lens material is optimally selected to provide one or more desired characteristics for a variety of applications related to adaptive lens devices. In another embodiment, a fluidic medium is optimally chosen to provide one or more desired characteristics for a variety of applications related to adaptive lens devices.

Abstract: The common zoom optical system is provided that is almost commonly used in a plurality of zoom lenses as a component and that is capable of suppressing fluctuation in aberrations and deviation in the position of the image plane, wherein the common zoom optical system is almost commonly used in a plurality of zoom lenses as a component, and when zooming from a wide-angle end state of a plurality of the zoom lenses composed by use of the common zoom optical system to a telephoto end state thereof, a moving path of the common zoom optical system differs for each zoom lens.

Abstract: A zoom lens system comprising a first lens unit having negative power, a second lens unit having positive power and a third lens unit having positive power, wherein in zooming from a wide-angle limit to a telephoto limit, the lens units move respectively along an optical axis in such a manner that an interval between the first lens unit and the second lens unit decreases while an interval between the second lens unit and the third lens unit changes so that variable magnification is achieved, the first lens unit comprises one object side negative lens element and one image side positive lens element with a convex surface facing the object side, which have an aspheric surface, and the conditions: n12>1.88 and ?12<26 (n12 and ?12 are refractive index and Abbe number, respectively, of the image side positive lens element of the first lens unit) are satisfied.

Abstract: A zoom lens includes 10 or less lens elements and having a zoom ratio of more than 20×, said zoom lens having first, second, third, and fourth groups of lens elements placed in turn from object side to image side; wherein the first group of lens elements has positive refractive power and is fixed in position during zooming; wherein the second group of lens elements has negative refractive power and is moved in position during zooming; wherein the third group of lens elements has positive refractive power, includes at least one aspheric surface, and is fixed in position during zooming; wherein the fourth group of lens elements has positive refractive power, includes at least one aspheric surface, corrects variations in image surface position during zooming, and performs focusing; and wherein the zoom lens satisfies the following conditional expression (1): 7.8 < dz fw < 8.

Abstract: An electronic imaging apparatus includes a zoom optical system having, in order from the object side, a first lens unit with positive power, a second lens unit with negative power, and an aperture stop, in which the first lens unit is composed of a single positive power unit and the second lens unit has a single negative lens element located at the most object-side position, both surfaces of which are concave, and a positive lens component located at the most image-side position; an electronic image sensor located on the image side of the zoom optical system; and an image processing section electrically processing image data obtained by the electronic image sensor to change the form thereof.

Abstract: There is provided a zoom lens of variable power ratio of the order of 3 in which the whole of the zoom lens is made up of three lens elements groups and the power configuration of each of the groups has an arrangement of negative, positive and negative, whereby the reduction in overall length of its optical system is enabled, so that a compact zoom lens and a camera with it can be provided. The zoom lens comprising, sequentially from an object side thereof, a first lens elements group has a negative refraction power as a whole, a second lens elements group has a positive refraction power as a whole and the third lens element group has a negative refraction power as a whole, and a variable power is realized by shifting the positions of the first and second lens elements group in the direction of an optical axis thereof.

Abstract: A linear motor table is provided in a lens switching apparatus of a laser repair apparatus. The linear motor table is fixed with respect to a table and a laser oscillator and moves a lens holder in a horizontal direction. Six objective lenses with magnifications different from each other are provided and are held in a lens holder in a row such that the optical axes thereof are parallel to each other. The objective lens placed in the light path of laser light is switched by the linear motor table moving the lens holder. Because of this, a member, such as a lens, can be positioned with high accuracy and if positional shifting occurs, it can be quickly cancelled using a simple mechanism.

Abstract: Low height imaging systems may include one or more optical channels and a detector array. Each of the optical channels may be associated with one or more detectors of the array, have one or more optical components and a restrictive ray corrector, and be configured to direct steeper incident angle field rays onto the detectors. Alternatively, each of the optical channels may be associated with at least one detector, and have an aspheric GRIN lens. Another low height imaging system has an array of detectors and a GRIN lens having a surface with wavefront coding and configured to direct steeper incident angle field rays onto more than one of the detectors. One method forms a lens with wavefront coding. The method includes positioning a lens in a mold; and curing material onto a surface of the lens to form an aspheric surface of the lens with wavefront coding.

Abstract: An imaging lens is provided and has, in order from the object side, a first lens of a positive lens having a convex surface on the object side thereof; a second lens in a meniscus shape having a concave surface on an image side thereof; a third lens in a meniscus shape having a convex surface on the image side thereof; and a fourth lens of a positive or negative lens, both surfaces of the fourth lens being aspheric and the fourth lens having a concave surface on the image side and in a vicinity of an optical axis of the fourth lens. The Abbe numbers of the first and second lenses as well as the focal distances of the first to fourth lenses satisfies specific conditions.

Abstract: At the time of crimping and fixing a plastic lens on a lens barrel, productivity is improved by achieving an accurate alignment and a reliable crimping. Fixed protrusions are arranged on an outer peripheral portion of the lens at intervals capable of providing three-point support, and a fixed protrusion is arranged on a line connecting the fixed protrusion and the center of the lens, a reference hole corresponding to one of the fixed protrusions includes an opening having substantially the same size as that fixed protrusion, and the other fixed protrusions have substantially the same size and fit in loosely fitting holes. The loosely fitting holes corresponding to the fixed protrusions include larger openings than the fixed protrusions and an elongated hole corresponding to another fixed protrusion is provided in such a manner as to be elongated along a direction of the reference hole.

Abstract: An optical recording and/or reproducing apparatus with an optical pickup actuator having high thrust. The optical pickup actuator may include a lens holder which holds an objective lens and is movably supported by a supporting unit, and a magnetic driving unit which drives the lens holder in a focusing direction, a tracking direction, and/or a tilting direction. The magnetic driving unit includes a surface-triple pole magnet portion and a coil portion. The surface-triple pole magnet portion has a plurality of polarized, i.e., differently magnetized, areas formed by facing sides of two magnets among three magnets. The coil portion includes tracking coils and tilt coils disposed to interact with the polarized areas of the surface-triple pole magnet portion and a focusing coil disposed to interact with a non-polarized area of the surface-triple pole magnet portion.

Abstract: A color wheel including a motor body, a housing, a spacer and a color filter. In this case, the housing is set to a side of the central axis of the motor body. The spacer is placed over the housing. The color filter is set on one side of the spacer, which is opposite the housing, so that there is a recess between the color filter and the housing.

Abstract: A recording control apparatus includes a waveform rectification section for receiving a digital signal generated from an analog signal representing information reproduced from an information recording medium, and rectifying a waveform of the digital signal; a maximum likelihood decoding section for performing maximum likelihood decoding of the digital signal having the waveform thereof rectified, and generating a binary signal representing a result of the maximum likelihood decoding; a reliability calculation section for calculating a reliability of the result of the maximum likelihood decoding based on the digital signal having the waveform thereof rectified and the binary signal; and an adjusting section for adjusting a shape of a recording signal for recording the information on the information recording medium based on the calculated reliability.

Abstract: System and method for write current drivers for inductive heads used in mass storage drives. A preferred embodiment comprises a write current circuit coupled to an inductive write head, a MOS transistor boost circuit and a matching circuit, both coupled to the write current circuit. The write current circuit provides a first current to the inductive write head, while the MOS transistor boost circuit provides a second current for a specified duration to the inductive write head when the MOS transistor boost circuit receives a control signal. The matching circuit selectively decouples a resistive element from the inductive write head when it receives the control signal. The MOS transistor boost circuit can accelerate the transition in a switching of the polarity of the write current and the matching circuit helps to reduce ringing without negatively affecting the speed of the polarity switching by decoupling when the second current is provided.

Abstract: A disk drive device has a shock sensor that detects mechanical shocks to a disk drive device to provide a shock output signal representative of such mechanical shocks. The shock output signal may be filtered to pass signals having a low frequency component of approximately between 1 and 4 KHz. Low frequency mechanical disturbances may be compensated for during writing to a track on the disk drive as a function of such low frequency component. In one embodiment, higher frequency shocks may be processed on a separate shock channel to inhibit or allow write operations. Different filters may be used on each of the shock channels.

Abstract: A method of servo writing a disk of a disk drive is disclosed, wherein the disk drive comprising the disk and a head actuated over the disk. Servo sectors are written to define servo tracks from a first diameter of the disk to substantially a middle diameter of the disk, wherein the first diameter is selected from one of the outer and inner diameter of the disk. Servo sectors are then written to define servo tracks from a second diameter of the disk toward the middle diameter of the disk by positioning the head over a current servo track, reading the current servo track to generate a read signal, processing the read signal to detect a previously written servo sector, and if a previously written servo sector is not detected, then writing servo sectors to the current servo track and positioning the head over a next servo track.

Abstract: Methods of estimating a flying height of a read/write head include determining an idle period of the head since a last selection of the head as a working head, estimating the residual temperature of the head in response to the idle period, and estimating the flying height of the head in response to the estimated residual temperature of the head.

Abstract: A disk drive includes a rotatable disk, a transducer, an actuator, and a controller. The disk includes a first servo burst pattern in a first radial spoke of the disk, and a second servo burst pattern in a second radial spoke of the disk. The first and second servo burst patterns are radially offset from each other and are associated with a plurality of data tracks extending through the first and second radial spokes. The transducer is configured to read the first and second servo burst patterns on the disk to generate a servo burst signal. The actuator is configured to position the transducer relative to the disk. The controller is configured to control positioning of the transducer relative to the tracks on the disk based on the servo burst signal.

Abstract: A magnetic disk apparatus is configured so as to read trace information from a discrete track recording medium recording the trace information for making a servo locus of a magnetic head trace the center line of physical tracks and control the servo locus of the magnetic head onto the center line of the physical tracks.

Abstract: Processing wherein a measurement signal and an erasure signal are recorded on adjacent tracks of a recordable tape 10 by one recording head HWi of n (i=1 to n) recording heads is effected on n recording heads, and measurement signals are recorded on n tracks substantially simultaneously by n recording heads HW1 to HWn in standard operation state. Then, reproducing heads with respect to thus obtained two kinds of tracks are displaced in track width directions, characteristic curves of reproduced signal waveform amplitudes of measurement signals displacement (off-track) amounts of tracks are obtained, half widths of these characteristic curves are assumed to be expedient track width and a variable Ri optimum and a variable Ri now corresponding to track widths of two kinds of tracks are obtained. Then, deviation between the variable Ri optimum and the variable Ri now is adjusted to become smaller than a desired value.

Abstract: A magnetic disk and spindle motor are mounted in a housing member. A support arm is freely rotatably mounted on a cover member. A suspension has a dimple (first mark) indicating the mount position of the magnetic head slider and a through hole (second mark) formed at any different position form the dimple. The cover member has measuring holes, through which the respective marks are observed from the opposite side to the support arm mount surface.

Abstract: A hard disk drive, hard (HDD) disk damper, and method for the same. The HDD may include a base member, a spindle motor installed on the base member, a plurality of data storage disks mounted on the spindle motor, an actuator pivotably installed on the base member to move a read/write head to a predetermined position on each of the disks, and a disk damper disposed between adjacent disks of the plurality of disks reducing vibrations of the disks. The disk damper has at least one groove, having a predetermined depth from an outer circumferential surface thereof, extending a predetermined length along the circumference of an outer edge thereof. Accordingly, a disk damper of the present invention can reduce vibrations of disks and protect data recording surfaces of the disks from external shocks.

Abstract: The present invention provides a method of manufacturing a thin film magnetic head capable of assuring recording characteristics by determining throat height with high precision. A TH specifying layer is formed so as to extend to a position P1 while being adjacent to a gap layer, and an auxiliary insulating layer is similarly formed so as to extend from the position P1 while being adjacent to the gap layer and specify throat height on the basis of the position P1. After that, a main insulating layer is formed so as to cover a thin film coil on the auxiliary insulating layer, and a yoke layer is formed so as to extend while being partially on the TH specifying layer. The throat height is determined accurately and stably on the basis of the position P1 by the auxiliary insulating layer.

Abstract: A suspension assembly elastically biasing a slider toward a surface of a disk, in which a read/write head is mounted on the slider. In the suspension assembly, a load beam is coupled to a first portion of a swing arm of the actuator. A flexure supports the slider and has a first end portion fixed to a disk facing surface of the load beam and a second end portion extended toward a first end portion of the load beam. An end-tab is extended from the first end portion of the load beam. When the head is parked, the end-tab is supported by a ramp, which is arranged at an outside of the disk.

Abstract: A pallet main body is provided with a block holding member which presses a positioning surface of an actuator block against a block reference surface formed in the pallet main body, and a movable arm. An insertion member, which can be inserted between a plurality of opposing suspensions, is formed at a distal end of the movable arm. As a suspension to which a slider is to be attached contacts a first contact surface formed on the side in contact with this suspension, a distal end of the suspension to which the slider is to be attached is held at a prescribed height from the block reference surface, thereby forming a gap between this suspension and a suspension opposed to this suspension.

Abstract: A magnetic head comprising for reading data from magnetic media includes a first magneto-resistive (MR) reader and a second MR reader. Both of the MR readers are either anisotropic magneto-resistive (AMR) readers or giant magneto-resistive (GMR) readers. The MR readers are tuned to sense magnetic flux differently such that the magnetic head is capable of reading two different types of magnetic media. The magnetic head may be configured such that the readers share sensor shields in various configurations in order to carry out their reading functions. The magnetic head may further include a writer. In this case, the magnetic head may be configured such that the writer and the readers share sensor shields in various configurations in order to carry out their writing and reading functions.

Abstract: A magnetoresistive device with a spin valve formed from a stack of layers including at least two magnetic layers for which the relative orientation of their magnetization directions can vary under the influence of a magnetic field, and comprising means of circulating a current in the spin valve transverse to the plane of the layers. The spin valve comprises at least one discontinuous dielectric or semiconducting layer in the stack, with electrically conducting bridges passing through the thickness of the dielectric or semiconducting layer, these bridges being designed to locally concentrate the current that passes transversely through the stack. Application particularly suitable for magnetic read heads, and random access memories.

Abstract: A magnetic tunneling junction device has a fixed ferromagnetic layer, a free ferromagnetic layer, and an insulating tunnel barrier layer made of gallium oxide. The insulating tunneling barrier layer is deposited by RF sputtering of gallium oxide. The magnetic tunneling junction device has a resistance area product less than 7 ?·?m2.

Abstract: A method for protecting an electrical generator which includes providing an electrical generator which is normally synchronously operated with an electrical power grid; providing a synchronizing signal from the electrical generator; establishing a reference signal; and electrically isolating the electrical generator from the electrical power grid if the synchronizing signal is not in phase with the reference signal.

Abstract: This invention relates to a speed monitor apparatus for monitoring speed and acceleration of rotating turbine equipment (turbomachinery) and for operating an overspeed trip to shut down the equipment in the event that the speed or acceleration exceed predetermined thresholds. The invention provides a speed monitor module having an input conditioner comprising: a multiplexer; an amplifier; and a comparator; in which the multiplexer selects an input signal from the sensor, or an input signal via a feedback loop from the comparator in dependence upon a test input, such that the input circuit may be tested by confirming that the amplifier oscillates when the feedback loop is enabled by the test signal.

Abstract: An RC-triggered electrostatic discharge (ESD) power clamp circuit and method for providing ESD protection uses a control circuit with a latch to selectively activate a clamping transistor to discharge ESD on a first voltage rail to a second voltage rail.

Abstract: A power and safety control hub, integrating fault tolerant power disconnect control, software monitoring of disconnect and multi-voltage power distribution and disconnect with non-hazardous power control, EMI filtering and multi-circuit current protection in a single unit, coordinating shutdown of connected mechanical drives, commanding them to come to a controlled stop before safety power is disconnected. The hub may also integrates segmented hazardous power control and automatically discharge energy sources within connected mechanical drives at the time of safety power disconnect of hazardous power. The hub may also include internal self-protection that automatically forces a control safety power disconnect (after warning the host) if the unit should approach its maximum operating temperature, or if a cooling fan stops.