A magnet operated display or indicator device selectably displays one of two faces of a disk. The disk is stopped in each limiting position by a stop contacting the disk inboard of its edge to another aspect the magnet is offset relative to the pivot axis of the disc to give better starting torques. In another aspect, where a plurality of disks are in columns, the pivot axes are stepped to be parallel but not coaxial.
An electromagnetic display device has a rotor rotatable between limiting positions and in said limiting positions to display contrasting faces in the viewing direction. The drive for the rotor uses a permanent magnet mounted on the rotor eccentrically of the rotary axis and a stator core mounted behind the rotor and on a line intersecting the rotor axis and parallel to the viewing direction.
A magnetically operated display element having contrasting opposite sides, is symmetrically mounted in a surrounding frame for pivoting about an axis. A permanent magnet within the display element has poles on opposite sides of the pivoting axis. A U-shaped electromagnet has its pole pieces positioned on opposite sides of the pivoting axis where they may interact with the poles of the permanent magnet. The permanent magnet has a asymmetrical magnetic construction relative to the pivoting axis. When the electromagnet is energized, the repulsion at one pole of the permanent magnet is always greater than at the other pole of the permanent magnet, causing rotation of the display element. The display element is statically and dynamically balanced.
A board usually resembling a PCB or a PWB mounts a display element, whose appearance in a viewing direction is controlled by the sense of magnetization of a core which extends through a bore in the board. A conducting coil formed on the surface of said board is located so that current in said coil will magnetize the core.
A changeable display element is edgewise mounted on an insulating board and carries to rotate through about 180.degree. to show one color face or the other to a viewer. The board provides a similarly colored face for each face to form a pixel. The element carries a permanent magnet and is driven by a switchable magnetic field provided from the board. Soft iron pads on the board cooperates with the magnet on each position to retain the element against incidental displacement between application of the field. The board may support arrays of such elements.
This dot assembly has a three-position rotor carrying dot display means for use as a portion of a matrix of dots in a variable message sign. The assembly has a stator including a support carrying reversely magnetizable separate magnetic cores on which are separate electrically energizable coils. The rotor which is carried by the support has a shaft rotated axially perpendicular to the cores. A permanent magnet on the rotor is adjacent to the cores to interact magnetically with them and rotate the shaft selectively to any one of three rotor positions. A single display disk having a peripheral display edge and two opposite display sides, or a unit of three disks having three exposed display sides, is mounted on the shaft for selective display of said edge or any one of the display sides in a viewing position.
