The disclosure relates to a drug delivery device having a drive unit includes a stator comprising a plurality of coils consecutively arranged in an axial direction, and an armature axially movable within the stator, the armature including a number of magnets and pole shoes consecutively arranged in the axial direction. A respective pole shoe is arranged between respectively neighbouring magnets. At least one axial end of the armature comprises a terminal pole shoe.

A motor drive device includes a motor drive circuit which drives a stepping motor provided with three coils; a switching element for controlling a path through which a current for driving at least one of the coils flows; and a driving pulse generator which outputs a driving pulse to the switching element. The driving pulse generator outputs the driving pulse to the switching element so that the current for driving at least one of the coils flows through one path.

A motor drive device includes a motor drive circuit which drives a stepping motor provided with three coils; a switching element for controlling a path through which a current for driving at least one of the coils flows; and a driving pulse generator which outputs a driving pulse to the switching element. The driving pulse generator outputs the driving pulse to the switching element so that the current for driving at least one of the coils flows through one path.

An X-Y movable stage with rotation is described. A fixed base comprises a magnetic bed with a checkerboard, hexagonal or pseudo-random pattern of alternating north and south poles on a grid. A movable puck moves and rotates on the base. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. Methods of mapping node locations, controllers, and applications are described. Embodiments for specific applications are described.

An X-Y movable stage with rotation is described. A fixed base comprises a magnetic bed with a checkerboard, hexagonal or pseudo-random pattern of alternating north and south poles on a grid. A movable puck moves and rotates on the base. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. Methods of mapping node locations, controllers, and applications are described. Embodiments for specific applications are described.

An X-Y movable stage with rotation and tilt is described. A fixed base comprises a magnetic bed with a checkerboard, hexagonal or pseudo-random pattern of alternating north and south poles on a grid. A movable puck moves, rotates and tilts on the base. The base and puck system is free of any other moving parts. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. Embodiments include use in a vacuum or fluid. Light from the base to the puck may be used to charge or power a puck. Methods of mapping node locations, controllers, and applications are described. Embodiments for specific applications are described.

An X-Y movable stage with rotation and tilt is described. A fixed base comprises a magnetic bed with a checkerboard, hexagonal or pseudo-random pattern of alternating north and south poles on a grid. A movable puck moves, rotates and tilts on the base. The base and puck system is free of any other moving parts. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. Embodiments include use in a vacuum or fluid. Light from the base to the puck may be used to charge or power a puck. Methods of mapping node locations, controllers, and applications are described. Embodiments for specific applications are described.

Aspects of the invention provide methods and systems for moving a plurality of moveable stages relative to a stator. The stator comprises a plurality of coils shaped to provide pluralities of coil trace groups where each coil trace group comprises a corresponding plurality of generally linearly elongated coil traces which extend across a stator tile. Each moveable stage comprises a plurality of magnet arrays. Methods and apparatus are provided for moving the moveable stages relative to the stator, where a magnet array from a first moveable stage and a magnet array from a second moveable stage both overlap a shared group of coil traces. For at least a portion of the time that the magnet arrays from the first and second moveable stages overlap the shared group of coil traces, currents are controllably driven in the shared coil trace group based on the positions of both the first and second moveable stages. The positions of the first and second moveable stages may be ascertained by feedback.

A displacement device comprises a stator comprising non-parallel stator-x and stator-y elongated traces. The device comprises a moveable stage comprising a first magnet array comprising first magnetization segments linearly elongated in a stage-x direction and having magnetization directions generally orthogonal to the stage-x direction. The first magnet array comprises a first pair of adjacent first magnetization segments comprising two first magnetization segments adjacent to one another in a stage-y direction non-parallel to the stage-x direction. Each first magnetization segment in the first pair has a corresponding magnetization direction oriented at a corresponding angle .sub.n about a corresponding stage-x axis as measured from a positive stage-z direction that is generally orthogonal to both the stator-x and stator-y directions. The corresponding angle .sub.n is one of 45+n90 where n is any integer. Each first magnetization segment in the first pair has a different magnetization direction.

A stepping motor includes a rotor, a stator and three coils. The rotor is two-pole magnetized in a radius direction. The stator is provided with a rotor receiving section for receiving the rotor. The three coils are magnetically connected with the stator. At least one of the three coils is an integrated coil which is integrally formed with the stator by winding a coil around a part of the stator.