Abstract: Methods and apparatus for increasing the efficiency of a voice coil motor (VCM) are disclosed. According to one aspect of the present invention, a cylindrical and radially symmetric VCM includes a plurality of sets of magnets, and a single coil. The plurality of sets of the magnets are each arranged in an array configuration, and cooperate to form a magnetic field. The coil receives current and has a plurality of windings. A first space is defined within the coil, and the plurality of sets of the magnets are arranged such that a first set of the magnets is positioned within the first space and a second set of the magnets is positioned external to the coil.

Abstract: Methods and apparatus for increasing the efficiency of a voice coil motor (VCM) are disclosed. According to one aspect of the present invention, a cylindrical and radially symmetric VCM includes a plurality of sets of magnets, and a single coil. The plurality of sets of the magnets are each arranged in an array configuration, and cooperate to form a magnetic field. The coil receives current and has a plurality of windings. A first space is defined within the coil, and the plurality of sets of the magnets are arranged such that a first set of the magnets is positioned within the first space and a second set of the magnets is positioned external to the coil.

Abstract: Methods and apparatus for increasing the efficiency of a voice coil motor (VCM) are disclosed. According to one aspect of the present invention, a cylindrical and radially symmetric VCM includes a plurality of sets of magnets, and a single coil. The plurality of sets of the magnets are each arranged in an array configuration, and cooperate to form a magnetic field. The coil receives current and has a plurality of windings. A first space is defined within the coil, and the plurality of sets of the magnets are arranged such that a first set of the magnets is positioned within the first space and a second set of the magnets is positioned external to the coil.

Abstract: An electrical plug and receptacle relying on magnetic force to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one or both of the plug and receptacle can be a magnet, which is preferably a permanent rare earth magnet although electromagnets may also be used. The magnetic element on the plug or receptacle that does not include a magnet is composed of ferromagnetic material. When the plug and receptacle are brought into proximity, the magnetic attraction between the magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: An electrical plug and receptacle relying on magnetic force from an electromagnet to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one of the plug or receptacle can be a magnet or ferromagnetic material. The magnetic element on the other of the plug or receptacle is an electromagnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the electromagnet magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: An electrical plug and receptacle relying on magnetic force to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one or both of the plug and receptacle can be a magnet, which is preferably a permanent rare earth magnet although electromagnets may also be used. The magnetic element on the plug or receptacle that does not include a magnet is composed of ferromagnetic material. When the plug and receptacle are brought into proximity, the magnetic attraction between the magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: An electrical plug and receptacle relying on magnetic force to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one or both of the plug and receptacle can be a magnet, which is preferably a permanent rare earth magnet although electromagnets may also be used. The magnetic element on the plug or receptacle that does not include a magnet is composed of ferromagnetic material. When the plug and receptacle are brought into proximity, the magnetic attraction between the magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: An electrical plug and receptacle relying on magnetic force from an electromagnet to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one of the plug or receptacle can be a magnet or ferromagnetic material. The magnetic element on the other of the plug or receptacle is an electromagnet. When the plug and receptacle are brought into proximity, the magnetic attraction between the electromagnet magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.

Abstract: Methods and apparatus for increasing the efficiency of a voice coil motor (VCM) are disclosed. According to one aspect of the present invention, a cylindrical and radially symmetric VCM includes a plurality of sets of magnets, and a single coil. The plurality of sets of the magnets are each arranged in an array configuration, and cooperate to form a magnetic field. The coil receives current and has a plurality of windings. A first space is defined within the coil, and the plurality of sets of the magnets are arranged such that a first set of the magnets is positioned within the first space and a second set of the magnets is positioned external to the coil.

Abstract: An apparatus for providing support between a first structure and a second structure is described. The apparatus includes a first section and a second section. The first section has a first group of at least one magnetic frame member, and is coupled to the first structure. The second section has a second group of at least one magnetic frame member, and is coupled to the second structure. The first and second sections present magnetic force therebetween.

Abstract: A magnetic coupling having two opposed annular arrays of angularly spaced permanent magnets magnetized to create magnetic north poles and magnetic south poles alternately spaced about each array. The north-pole and south-pole magnets of each array are tapered in cross-section from their surfaces at the gap to an annular surface of the array spaced from the gap, and permanent magnet spacer magnets completely fill in the space between the north-pole and south-pole magnets from the annular surface of the array at the gap to the spaced annular surface with the spacer magnets being magnetized generally transversely to the direction of magnetization of the adjacent north-pole, south-pole magnets so that the magnetic field created by the permanent magnets extends across the gap and annularly through each array to cause one of the arrays to rotate in synchronism with the other array.

Abstract: A magnetic coupling having two opposed annular arrays of angularly spaced permanent magnets magnetized to create magnetic north poles and magnetic south poles alternately spaced about each array. The north-pole and south-pole magnets of each array are tapered in cross-section from their surfaces at the gap to an annular surface of the array spaced from the gap, and permanent magnet spacer magnets completely fill in the space between the north-pole and south-pole magnets from the annular surface of the array at the gap to the spaced annular surface with the spacer magnets being magnetized generally transversely to the direction of magnetization of the adjacent north-pole, south-pole magnets so that the magnetic field created by the permanent magnets extends across the gap and annularly through each array to cause one of the arrays to rotate in synchronism with the other array.

Abstract: An apparatus for providing support between a first structure and a second structure is described. The apparatus includes a supporting member, and first and second sections. The supporting member is mounted to the first structure and second structure, and has positive stiffness with respect to a lateral direction. The first section has at least one magnetic member, and is coupled to the first structure. The second section has at least one magnetic member, and is coupled to the second structure. The first and second sections present negative stiffness caused by magnetic attractive force at a neutral position, thereby canceling at least a part of the positive stiffness of the supporting member.

Abstract: An apparatus for providing support between a first structure and a second structure is described. The apparatus includes a first section and a second section. The first section has a first group of at least one magnetic frame member, and is coupled to the first structure. The second section has a second group of at least one magnetic frame member, and is coupled to the second structure. The first and second sections present magnetic force therebetween.

Abstract: A magnet array having a plurality of alternating polarity (N and S) magnets as well as transverse magnets disposed in a plane is disclosed. The N and S magnets have opposing polarities and are arranged in a checkerboard pattern in the magnet array. The transverse magnets are disposed between immediate adjacent N and S magnets. The transverse magnets facilitate the forming of a continuous magnetic flux path through the transverse magnet and immediate adjacent N and S magnets. The magnet array of the present invention may be utilized in an electric motor or a positioning device comprising a coil array positioned adjacent to a magnet array where the coil array is operable to interact with the magnetic fields of the magnet array to provide a force therebetween. The magnet array may also be utilized in an exposure apparatus such as a photolithography system to position and support a wafer for photolithography processing in the manufacturing of semiconductor devices.

Abstract: A two-dimensional electric motor having a moving magnet and positionable in six degrees of freedom. The electric motor has a coil array and a magnet array. The magnet array has a smaller width than the coil array in the moving magnet embodiment. The invention's process of achieving motion of a coil array with respect to a magnet array in six degrees of freedom includes providing an electrical current distribution to a coils. The motion is controlled in a first direction and a vertical direction between a portion of the coils and a portion of the magnet array. The electrical current distribution has two wavelike components having a same period but approximately ninety degrees out of phase. The invention's positioning devices do not require air bearings. Instead, the suspension of the support member by magnetic attraction to the frame or by interaction of the coil array and the magnet array replace the air bearings.

Abstract: Wedge magnet arrangements for use in a magnet array. A magnet arrangement has each wedge magnet with a magnetic flux polarized at the same angle with respect to a reference direction. The magnets are juxtaposed each other in a reference plane such that their respective magnetic fluxes combine to form a net magnetic flux along a reference direction perpendicular to the reference plane and a negligible magnetic flux in the reference plane. Transverse magnets along a plane complete flux paths between magnet arrangements and wedge magnets in the magnet array to eliminate the need for a heavy magnetically permeable backing for the magnet array. The magnet arrays have a high flux-to-mass ratio. This greater ratio improves the efficiency of two-dimensional electric motors which incorporate the magnet arrays as the moving part of the motors.

Abstract: A linear motor, suitable to drive a photolithography positioning stage, incorporates a magnet array having transverse magnets and wedge magnets. The transverse magnets are spaced at regular intervals along a direction parallel with their magnetic polarities. Each transverse magnet is linked by a closed magnetic flux circuit with two adjacent wedge magnets having magnetic polarities oriented at an angle relative to the transverse magnet polarities. The local flux direction is substantially parallel to the magnetic polarity within each magnet, effectively enhancing magnetic flux density. Magnetic flux circuits are completed directly through the magnets and not through side rails, allowing selection of stronger, lighter-weight nonmagnetic side rail material. Wedge magnets with rectangular and trapezoidal cross-sectional shapes are described. Alternative array configurations contain two rows of complementary transverse and wedge magnets spaced on opposite sides of a coil array.

Abstract: A glide head for detecting anomalies on a flat surface of a recording disk includes a slider having a sensing edge extending generally radially of the disk and a piezoelectric transducer element attached to one face of the slider and extending therefrom in cantilever fashion. The transducer element is of segmented shape and has a pair of opposed surfaces facing towards and away from the disk surface with spaced electrodes being provided thereon so as to provide stress readings only at specific locations on the body of the transducer element chosen to accentuate particular vibrational modes induced by anomalies on the disk surface.

Abstract: A dipole magnet structure includes a pair of spaced pole pieces and a pair of permanent magnets secured in alignment with the pole pieces and connected by a magnetically conductive yoke for producing a uniform magnetic field within a predetermined spacial volume therebetween. The opposed faces of the pole pieces are dish-shaped with a flat center area surrounded by an outwardly and forwardly curved rim surface which extends from the center area and which increases in forward curvature as it extends away from the center area to insure homogeneity in the predetermined spacial volume as defined by the space between the pole piece center areas.