Optical storage media light beam positioning system

• US 5,291,473 A
• Filed: 06/06/1990
• Issued: 03/01/1994
• Est. Priority Date: 06/06/1990
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Pauli, Giles A.
• Primary Examiner(s): Psitos, Aristotelis
• Assistant Examiner(s): HUBER, PAUL W
• Application Number:
  US07/534,103
• Time in Patent Office: 1,364 Days
• Field of Search: 369/112, 369/120, 369/117, 369/121, 369/94, 369/95, 369/44.14, 369/44.23, 359/198, 359/199, 359/214, 359/221, 359/224, 359/855
• US Class Current: 369/112.29
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G11B 7/08564 using galvanomirrors
• CPC Class Codes: G11B 7/0901 for track following only G11B7/0925, G11B7/094, G11B7/0941, G11B7/0943, G11B7/0945, G11B7/0946, G11B7/0948 take precedence
• CPC Class Codes: G11B 7/1362 Mirrors

Abstract

An optical tracking system 10 is provided which comprises a beam source 12 which generates a light beam. The light beam travels through a splitter/filter 14 and proximate a DMD array 16. The DMD array 16 is controlled by a DMD array control system 18 which causes a single element within the DMD array to deflect the light beam towards a selected track on an optical storage medium 22. The optical storage medium 22 reflects the beam dependent upon the data stored on the selected track. The reflected beam is deflected by the DMD array 16 back to the splitter/filter 14 which separates the reflected beam from the impinging beam and directs the reflected beam to a detector 24 which discerns the information stored in the storage medium 22 responsive to the receipt of the reflected beam.

Claims

1. An optical tracking system of directing a beam of light used to access an optical storage medium, comprising:

a light beam source for generating a beam of light;

an array control system for selectively transmitting a deflection signal;

an array comprising a plurality of mirror elements, each of said mirror elements formed on a common substrate and comprising a mirrored outer surface and an address electrode disposed inwardly from said mirrored outer surface, said address electrode for receiving said deflection signal, said deflection signal for deflecting said mirrored outer surface, wherein said beam of light is reflected by said mirrored outer surface to form an impinging beam;

an optical storage medium wherein said impinging beam is reflected by said optical storage medium to create a reflected beam; and

a detector disposed in the path of said reflected beam and operable to discern the data stored on the optical storage medium responsive to the receipt of said reflected beam.

2. The system of claim 1 wherein said impinging beam and said reflected beam have substantially coincident paths, the system further comprising a beam splitter disposed in said coincident paths and operable to direct said reflected beam to said detector.

3. The system of claim 1 wherein said optical storage medium comprises a number of tracks, each of said tracks comprising a plurality of data storage locations, said array having a number of elements not less than said number of tracks such that each of said tracks is associated with one of said elements.

4. The system of claim 1 wherein said optical storage medium comprises a number of tracks, each of said tracks comprising a plurality of data storage locations, said array having a number of elements less than said number of tracks such that not all said tracks are accessible from a single position of said array, said array control system comprising:

an array positioning system operable to position said array relative to the optical storage medium such that each of said tracks may be selectively accessed.

5. The system of claim 1 wherein said array control system comprises circuitry for independently and selectively activating an address electrode associated with each of said elements.

6. The system of claim 1 and further comprising a beam widener disposed in the path of the beam between said light beam source and said array and operable to widen the beam generated by said source such that said widened beam simultaneously impinges on each element in said array.

7. The system of claim 1 wherein said mirror elements comprising:

a torsion beam having a mirrored outer surface; and

a torsion rod coupling said torsion beam to said substrate;

wherein said deflection signal is operable to rotate said torsion beam about said torsion rod.

8. An optical tracking system for directing a beam of light used to access an optical storage medium, comprising:

a light beam source for generating the beam;

an array comprising a linear array of deformable mirror devices formed on a substrate, each of said deformable mirror devices comprising a torsion beam having a mirrored outer surface, a torsion rod coupling said torsion beam to said substrate, and an address electrode disposed inwardly from said mirrored outer surface, said address electrode for receiving a deflection signal;

an array control system operable for selectively transmitting said deflection signal to said address electrode;

a beam widener disposed in the path of the beam between said light beam source and said array and operable to widen the beam generated by said source such that said widened beam impinges on each of said elements in said array; and

said optical storage medium operable to reflect the beam, a detector disposed in the path of said reflected beam and operable to discern the data stored in the selected portion of the optical storage medium responsive to the receipt of said reflected beam.

9. The system of claim 8 wherein said array control system comprises circuitry for independently and selectively activating an address electrode associated with each of said elements.