Method of writing servo signal on magnetic tape

• US 6,741,415 B1
• Filed: 03/25/2002
• Issued: 05/25/2004
• Est. Priority Date: 02/16/1999
• Status: Expired due to Fees

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Okuda, Shinsuke, Ishii, Takashi
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): WONG, KIN C
• Application Number:
  US09/890,898
• Time in Patent Office: 792 Days
• Field of Search: 360/75, 360/25, 360/77.12, 360/77.13, 360/313, 369/13.02, 369/14, 216/65
• US Class Current: 360/75
• CPC Class Codes: G11B 23/30 with provision for auxiliary signals
• CPC Class Codes: G11B 5/584 for track following on tapes
• CPC Class Codes: G11B 5/588 by controlling the position of the rotating heads by controlling the speed of the record carrier G11B15/467; by controlling speed of the heads G11B15/473; by moving the transducing part of the head relative to the headwheel, in the direction of the scanning movement G11B15/1841

Abstract

A method of writing servo signals on a magnetic tape which comprises irradiating one end of an optical fiber bundle (12) comprising a plurality of optical fibers (11) arrayed in parallel with each other with laser light, transmitting the laser light (24) emitted from the other end as an output light source through a condensing lens (13), and irradiating a site of a magnetic tape running at a prescribed speed, the site being capable of forming servo tracks, with the laser light passed through the condensing lens (13) to form real images (25) equal to or smaller in size than the output light source to cause the site to change physically or chemically thereby forming a plurality of servo track patterns (S) in the longitudinal direction of the tape at a smaller pitch than the pitch of the optical fibers (11) arrayed in the optical fiber bundle (12).

Claims

1. A method of writing servo tracks on tape which comprises irradiating a first end of an optical fiber bundle comprising a plurality of optical fibers arrayed in parallel with each other with laser light, transmitting the laser light emitted from a second end of the fiber bundle as an output light source through reducing optics, and irradiating a site of the tape, said site being capable of forming servo tracks, with the laser light transmitted through said reducing optics to form a plurality of servo track patterns in a running direction of the tape at a smaller pitch than the pitch of the optical fibers arrayed in said optical fiber bundle.

2. The method of claim 1, wherein said optical fiber bundle comprises the optical fibers arrayed with the center axes of the individual optical fibers being coplanar, and irradiation of said site with said laser light is such that the direction in which the real images of said output light source formed on the tape are aligned and the running direction of the tape may make an angle larger than 0°

and smaller than 90°

.

3. The method of claim 1, wherein said optical fiber bundle comprises the optical fibers arrayed with the center axes of the individual optical fibers being coplanar, two or more of said optical fiber bundles are superposed on each other in such an arrangement that real images may be formed at a smaller pitch than the pitch of the real images formed by the individual optical fiber bundles.

4. The method of claim 1, wherein said reducing optics comprise a condensing lens.

5. The method of claim 1, wherein the laser light transmitted through said reducing optics forms real images on the site having a size equal to or smaller in size than the output light source.

6. The method of claim 1, further comprising irradiating the first end of a first optical fiber in said optical fiber bundle with a first laser light, and irradiating the first end of a second optical fiber in said optical fiber bundle with a second laser light.

7. The method of claim 6, further comprising controlling the first laser light with a first controller and controlling the second laser light with a second controller.

8. The method of claim 1, wherein the tape is magnetic tape.

9. The method of claim 1, wherein the tape runs at a prescribed speed in the running direction as it is irradiated.

10. An apparatus for writing servo tracks on a tape which comprises a system for running said tape, a system for writing servo signals on said tape, and a light source system providing laser light incident upon said servo signal writing system, wherein:

said servo signal writing system has an optical fiber bundle where a plurality of optical fibers are arrayed in parallel to each other with the center axes of the individual optical fibers being coplanar and reducing optics which receives the laser light emitted from the end of said optical fiber bundle, said optical fiber bundle and said lens being disposed such that the direction in which real images of the output laser light source formed through said lens are aligned and the running direction of said magnetic tape may make an angle larger than 0° and

smaller than 90°

.

11. An apparatus for writing servo tracks on a tape which comprises a system for running said tape, a system for writing servo signals on said tape, and a light source system providing laser light incident upon said servo signal writing system, wherein:

said servo signal writing system has a group of two or more optical fiber bundles each having a plurality of optical fibers arrayed in parallel to each other with the center axes of the individual optical fibers being coplanar, said optical fiber bundles being superposed on each other in such a manner that real images may be formed at a smaller pitch than the pitch of real images formed by the individual optical fiber bundles.

12. An apparatus for writing servo tracks on a tape comprising:

a system for running said tape in a running direction;

a system for writing servo signals on said tape, the system for writing servo signals including an optical fiber bundle having a plurality of optical fibers arrayed in parallel with each other; and

a light source system for providing laser light incident upon a first end of the fiber bundle,

wherein the system for writing servo signals transmits the laser light emitted from a second end of the fiber bundle as an output light source through reducing optics to form servo track patterns on the tape in the running direction at a smaller pitch than the pitch of the optical fibers arrayed in said optical fiber bundle.

13. The apparatus of claim 12, wherein said reducing optics comprise a condensing lens.

14. The apparatus of claim 12, wherein the laser light transmitted through said reducing optics forms servo track patterns having a size equal to or smaller than the output light source.

15. The apparatus of claim 12, further comprising a first laser source for irradiating the first end of a first optical fiber in said optical fiber bundle with a first laser light, and a second laser source for irradiating the first end of a second optical fiber in said optical fiber bundle with a second laser light.

16. The apparatus of claim 15, further comprising at least one controller for controlling the first laser light with a first controller and controlling the second laser light with a second controller.

17. The apparatus of claim 12, wherein the tape is magnetic tape.

18. The apparatus of claim 12, wherein the optical fibers in the fiber bundle have center axes arrayed in a coplanar manner, at least two such optical fiber bundles are superposed on each other so that the servo tracks may be formed at a smaller pitch than the pitch of real images formed by the individual optical fiber bundles.