Portable optical card readers
A device for reading optical data cards. This device includes a shuttle mounted on shuttle tracks within the device housing. The shuttle is configured to move back and forth on the shuttle tracks driven by the shuttle motor. A card loader allows optical data cards to be positioned onto the shuttle. A CD optical read head mounted on optical read head tracks and driven by a optical head motor reads modified to read a single track of optical card data reads the optical card. A controller receives data from the read head and controls the movement of the shuttle and the optical head.
1. A reader for reading optical cards having optical data tracks flanked on two sides by tracking strips, said reader having a shuttle for holding said optical card and a motor linked to said shuttle such that the optical card can be moved on a shuttle axis, the improvement comprising:
a CD read head oriented at a CD read head angle such that three illumination beam spots produced by said CD read head are targeted onto a first tracking strip, a targeted optical data track, and a second tracking strip respectively, wherein said CD read head angle is at a different angle than perpendicular to said shuttle axis.
2. The reader of claim 1 , wherein said CD read head angle is 18.5 degrees.
3. The reader of claim 1 , wherein said CD read head is driven by a stepper motor driving a lead screw.
4. The reader of claim 1 , wherein said CD read head transmits data to a controller, said controller including a plurality of simultaneously running state machines.
5. The reader of claim 4 , wherein said controller generates a track count from a read and a tracking error signal.
6. The reader of claim 1 , wherein said CD read head further comprises an objective lens configured to correct for an aberration produced during reading of optical cards.
7. The reader of claim 1 , wherein said CD read head further comprises an objective lens with an angular ring mounted on an exposed surface of said objective lens.
8. The reader of claim 1 , wherein said CD read head further comprises an objective lens with numerical aperture of approximately 0.32.
9. The reader of claim 1 , wherein said beam spots provide a tracking signal.
10. The reader of claim 9 , wherein said CD read head further comprises an objective lens with numerical aperture of approximately 0.32, said objective lens configured to correct for an aberration produced during reading of optical cards and comprising an angular ring mounted on an exposed surface.