A low mass optical head system

Claim 2

An optical data storage drive system, comprising a data storage medium having a plurality of adjacent tracks capable of storing optically accessible data, a movable track selection head carrying a focusing element in proximity with said medium, a beam control unit having a fixed location for controlling and transmitting an energy beam to said focusing element, said focusing element concentrating said beam on a focused spot on said medium, a head actuator for moving the head in a cross track direction for coarse track selection without changing the location of said beam control unit, and a remote fine tracking system located in said beam control unit for shifting said beam to effect fine track selection by correspondingly shifting the focused spot relative to said head in the cross track direction.

Claim 3

The system of claim 1, wherein said beam control unit is stationary.

Claim 4

The system of claim 1, wherein said fine tracking system includes means for changing the local angle of incidence of said beam along the optical path from said beam control unit to said focusing element in said head to shift the focused spot laterally.

Claim 5

The system of claim 1, wherein said fine tracking system includes a movable optical element and a fine tracking actuator for moving said optical element in a direction to achieve cross track displacement of said focused spot.

Claim 6

The system of claim 1, wherein said fine tracking system includes an optical relay including an optical element movable in a direction to cause a corresponding cross track shift in the focused spot.

Claim 7

An optical data storage drive system, comprising a data storage medium having a plurality of adjacent tracks capable of storing optically accessible data, a movable track selection head carrying a focusing element in proximity with the medium, a beam control unit having a fixed location for controlling and transmitting a beam to said focusing element, said focusing element concentrating said beam on a focused spot on said medium, a head actuator for moving the head in a cross track direction for coarse track selection without changing the location of said beam control unit, and a remote focusing system located in said beam control unit for moving the focused spot axially to keep the spot focused effectively on said medium.

Claim 8

An optical data storage drive system, comprising a data storage medium having a plurality of adjacent tracks capable of storing optically accessible data, a movable track selection head carrying a focusing element in proximity with the medium, a beam control unit having a fixed location for controlling and transmitting a beam to said focusing element, said focusing element concentrating said beam on a focused spot on said medium, a head actuator for moving the head in a cross track direction for coarse track selection without changing the location of said beam control unit, and a remote focusing system located in said beam control unit for moving the focused spot axially to keep the spot focused effectively on said medium.

Claim 9

The system of claim 6, wherein said beam control unit is stationary.

Claim 10

The system of claim 6, wherein said focusing system includes means for adjusting the degree of local convergence or divergence of the energy beam along the optical path from the beam control unit to the movable head to direct the focused spot of the projected beam to a desired axial location.

Claim 11

The system of claim 6, wherein said focusing system includes a movable optical element located in said beam control unit.

Claim 12

The system of claim 6, wherein said focusing system includes an optical relay system including a movable optical element and an actuator for moving the optical element in a direction corresponding to axial displacement of the focused spot.

Claim 13

An optical data storage drive system, comprising a data storage medium having a plurality of adjacent tracks capable of storing optically accessible data, a movable track selection head carrying a focusing element in proximity with the medium, a beam control unit having a fixed location for controlling and transmitting a beam to said focusing element, said focusing element concentrating said beam on a focused spot on the medium, a head actuator for moving the head in a cross- track direction for coarse track selection without changing the location of said beam control unit, a remote fine tracking system located in said beam control unit for shifting said beam to effect fine track selection by correspondingly shifting the focused spot relative to said head in the cross-track direction, and a remote focusing system located in said beam control unit for axially shifting the focused spot.

Claim 14

An optical data storage drive system, comprising a data storage medium having a plurality of adjacent tracks capable of storing optically accessible data, a movable track selection head carrying a focusing element in proximity with the medium, a beam control unit having a fixed location for controlling and transmitting a beam to said focusing element, said focusing element concentrating said beam on a focused spot on the medium, a head actuator for moving the head in a cross- track direction for coarse track selection without changing the location of said beam control unit, a remote fine tracking system located in said beam control unit for shifting said beam to effect fine track selection by correspondingly shifting the focused spot relative to said head in the cross-track direction, and a remote focusing system located in said beam control unit for axially shifting the focused spot.

Claim 15

The system of claim 11, wherein said beam control unit is stationary.

Claim 16

The system of claim 11, wherein said fine tracking system includes means for changing the local angle of incidence of said beam along the optical path from said beam control unit to said focusing element in said head to shift the focused spot laterally and said focusing system includes means for adjusting the degree of local convergence or divergence of the energy beam along the optical path from the beam control unit to the movable head to direct the focused spot of the projected beam to a desired axial location.

Claim 17

The system of claim 11, wherein said fine tracking and focusing systems comprise a common movable optical element.

Claim 18

The system of claim 14, further comprising a fixed optical element in said beam control unit coupled with said movable optical element to form an optical relay.

Claim 19

The system of claim 14, further comprising means for moving said movable optical element axially for remote focusing and perpendicularly for remote fine tracking.