Claims
- 1. A dithering assembly comprising
- a fixed member;
- a mirror assembly comprising a mirror bracket and a dithering mirror mounted on the mirror bracket, the mirror bracket being pivotally mounted to the fixed member to allow the mirror bracket to pivot about a center of rotation axis in at least two opposite directions;
- a electromagnetic drive assembly comprising at least a first drive magnet and at least a first electro-magnet, one of the first drive magnet and the first electro-magnet being fixedly mounted on the fixed member, wherein the first drive magnet is positioned proximate to the first electro-magnet, wherein the first drive magnet is driven by a magnetic field generated by the first electro-magnet as a flow of current is applied to the first electro-magnet;
- position sensing mechanism including
- a feedback magnet mounted on a side of the mirror bracket opposite to the first drive magnet,
- a Hall sensor mounted in a fixed position adjacent the feedback magnet for sensing position of the mirror assembly.
- 2. A dithering assembly according to claim 1 wherein the Hall sensor comprises an integrated circuit including an amplifier.
- 3. A dithering assembly according to claim 1 wherein the feedback magnet is positioned having a magnetic axis oriented horizontally relative to the Hall sensor with motion of the feedback magnet being parallel to its magnetic axis.
- 4. A dithering assembly according to claim 1 further comprising a printed circuit board, wherein the first electro-magnet comprises a drive coil and wherein the Hall sensor and the drive coil are mounted on the printed circuit board.
- 5. A dithering assembly according to claim 1 incorporated into a scan module, the scan module comprising a housing, a beam source generating a reading beam and directing the reading beam onto the dithering mirror, a collection lens for focusing return signal from an object being scanned, a detector for detecting and converting the return signal into an electrical signal, and a printed circuit board disposed on one side of the housing, wherein the Hall sensor, the detector and the first electro-magnet are mounted on the printed circuit board.
- 6. A dithering assembly according to claim 5 wherein the printed circuit board includes a controller for receiving the signal from the Hall sensor and controlling the flow of current applied to the first electro-magnet.
- 7. A compact scan module comprising
- a fixed member;
- a mirror assembly comprising a mirror bracket and a dithering mirror mounted on the mirror bracket, the mirror bracket being pivotally mounted to the fixed member allow the mirror bracket to pivot about a pivoting axis in at least two opposite directions;
- at least a first drive magnet mounted on the mirror bracket on one side of the pivoting axis;
- a first electromagnet mounted in a fixed position proximate the first drive magnet, wherein the first drive magnet is respectively attracted or repelled to the respective first electromagnet as a flow of current is applied to the first electromagnet in a controlled manner;
- a feedback magnet mounted on a side of the mirror bracket opposite to the first drive magnet;
- a position sensor mounted in a fixed position adjacent the feedback magnet for sensing position of the mirror assembly;
- a printed circuit board disposed on one side of the scan module,
- wherein the detector, the first electromagnet and the position sensor are mounted on the printed circuit board.
- 8. A compact scan module according to claim 7 wherein all electronic components of the scan module are mounted on the printed circuit board.
- 9. A compact scan module according to claim 7 wherein the position sensor comprises a Hall sensor.
- 10. A compact scan module according to claim 7 wherein the position sensor comprises a feedback coil.
Parent Case Info
This application is a continuing application of provisional application Ser. No. 60/027,487 filed Sep. 26, 1996 and provisional application Ser. No. 60/026,536 filed Sep. 23, 1996.
US Referenced Citations (10)