Optical disk drive system for use with disks having different protection layer depths

Claim 2

An aberration compensation system comprising: a focus device for receiving a beam of light from a light source and focussing the beam of light to a focus point at a first and a second depth in a transmissive medium, the focus device focussing the beam of light to the first depth without spherical aberration; an aberration compensator lens in optical communication with the focus device, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in spaced apart relationship, a variable index of refraction material located between the first and second substrates, a device for switching the variable index of refraction material between a first and a second index of refraction, the second substrate having a surface facing the variable index of refraction material which has a substantially sinusoidal cross-section having at least one substantially sinusoidal peak portion and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the transmissive medium.

Claim 3

The system of claim 1, wherein the variable index of refraction material comprises a liquid crystal.

Claim 4

The system of claim 1, wherein the variable index of refraction material comprises a nematic liquid crystal.

Claim 5

The system of claim 1, wherein the variable index of refraction material comprises a sematic liquid crystal.

Claim 6

The system of claim 1, wherein the device for switching the variable index of refraction material comprises a first transparent electrode located between the first substrate and the variable index of refraction material, and a second transparent electrode located between the second substrate and the variable index of refraction material.

Claim 7

The system of claim 5, wherein the variable index of refraction material comprises a liquid crystal and further comprising a first liquid crystal alignment film located between the first electrode and the liquid crystal, and a second liquid crystal alignment film located between the second electrode and the liquid crystal.

Claim 8

The system of claim 6, wherein the first and second alignment films are comprised of polyvinyl alcohol.

Claim 9

The system of claim 1, wherein the surface of the second substrate has a cross-section having a central sinusoidal valley portion and a sinusoidal peak portion on either side of the central sinusoidal valley portion.

Claim 10

The system of claim 1, wherein the transmissive medium is an optical data storage medium.

Claim 11

The system of claim 1, wherein the means for maintaining the first and second substrates in spaced apart relationship comprises an epoxy layer.

Claim 12

An aberration compensation system comprising: a focus device for receiving a beam of light from a light source and focussing the beam of light to a focus point at a first and a second depth in a transmissive medium, the focus device focussing light to the first depth without spherical aberration; and an aberration compensator lens in optical communication with the focus lens, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in a spaced apart relationship, a liquid crystal material located between the first and second substrates, the first substrate having a flat first surface facing the liquid crystal material, a first transmissive electrode overlying the first surface, a first liquid crystal alignment film overlying the first transmissive electrode, the second substrate having a second surface facing the liquid crystal material, a second transmissive electrode overlying the second surface, a second liquid crystal alignment film overlying the second transmissive electrode, the second surface having a substantially sinusoidal cross-section having at least one substantially sinusoidal peak and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the transmissive medium.

Claim 13

An aberration compensation system comprising: a focus device for receiving a beam of light from a light source and focussing the beam of light to a focus point at a first and a second depth in a transmissive medium, the focus device focussing light to the first depth without spherical aberration; and an aberration compensator lens in optical communication with the focus lens, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in a spaced apart relationship, a liquid crystal material located between the first and second substrates, the first substrate having a flat first surface facing the liquid crystal material, a first transmissive electrode overlying the first surface, a first liquid crystal alignment film overlying the first transmissive electrode, the second substrate having a second surface facing the liquid crystal material, a second transmissive electrode overlying the second surface, a second liquid crystal alignment film overlying the second transmissive electrode, the second surface having a substantially sinusoidal cross-section having at least one substantially sinusoidal peak and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the transmissive medium.

Claim 14

The system of claim 11, wherein the liquid crystal material is comprised of a nematic liquid crystal.

Claim 15

The system of claim 11, wherein the liquid crystal material is comprised of a sematic liquid crystal.

Claim 16

The system of claim 11, wherein the first and second alignment films are comprised of polyvinyl alcohol.

Claim 17

The system of claim 11, wherein the surface of the second substrate has a cross-section having a central sinusoidal valley portion and a sinusoidal peak portion on either side of the central sinusoidal valley portion.

Claim 18

The system of claim 11, wherein the transmissive medium is an optical data storage medium.

Claim 19

The system of claim 11, wherein the device for maintaining the first and second substrates in spaced apart relationship comprises an epoxy layer.

Claim 20

The system of claim 11, wherein the liquid crystal material has a first and a second index of refraction, the first index of refraction being equal to the index of refraction of the second substrate.

Claim 21

An aberration compensation system comprising: a light source for providing a beam of light; a device for receiving an optical data storage medium; a device for focussing the beam of light to a focus point at a first and a second depth in an optical data storage medium, the focus device focussing light to the first depth without spherical aberration; an aberration compensator lens in optical communication with the focus device, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in spaced apart relationship, a variable index of refraction material located between the first and second substrates, a device for switching the variable index of refraction material between a first and a second index of refraction, the second substrate having a surface facing the variable index of refraction material which has a substantially sinusoidal cross-section having at least one substantially sinusoidal peak portion and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the optical data storage medium; an optical reception device for receiving a light beam from the optical data storage medium and providing a data signal responsive thereto.

Claim 22

An aberration compensation system comprising: a light source for providing a beam of light; a device for receiving an optical data storage medium; a device for focussing the beam of light to a focus point at a first and a second depth in an optical data storage medium, the focus device focussing light to the first depth without spherical aberration; an aberration compensator lens in optical communication with the focus device, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in spaced apart relationship, a variable index of refraction material located between the first and second substrates, a device for switching the variable index of refraction material between a first and a second index of refraction, the second substrate having a surface facing the variable index of refraction material which has a substantially sinusoidal cross-section having at least one substantially sinusoidal peak portion and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the optical data storage medium; an optical reception device for receiving a light beam from the optical data storage medium and providing a data signal responsive thereto.

Claim 23

The system of claim 19, wherein the variable index of refraction material comprises a liquid crystal.

Claim 24

The system of claim 19, wherein the variable index of refraction material comprises a nematic liquid crystal.

Claim 25

The system of claim 19, wherein the variable index of refraction material comprises a semantic liquid crystal.

Claim 26

The system of claim 19, wherein the device for switching the variable index of refraction material comprises a first transparent electride located between the first substrate and the variable index of refraction material, and a second transparent electrode located between the second substrate and the variable index of refraction material.

Claim 27

The system of claim 23, wherein the variable index of refraction material comprises a liquid crystal and further comprising a first liquid crystal alignment film located between the first electrode and the liquid crystal, and a second liquid crystal alignment film located between the second electrode and the liquid crystal.

Claim 28

The system of claim 24, wherein the first and second alignment films are comprised of polyvinyl alcohol.

Claim 29

The system of claim 19, wherein the surface of the second substrate has a cross-section having a central sinusoidal valley portion and a sinusoidal peak portion on either side of the central sinusoidal valley portion.

Claim 30

The system of claim 19, wherein the means for maintaining the first and second substrates in spaced apart relationship comprises an epoxy layer.

Claim 31

An aberration compensation system comprising: a light source for providing a beam of light; a device for receiving an optical data storage medium; a focus device for focussing the beam of light to a focus point at a first and a second depth in an optical data storage medium, the focus device focussing the beam of light to the first depth without spherical aberration; an aberration compensator lens in optical communication with the focus lens, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in a spaced apart relationship, a liquid crystal material located between the first and second substrates, the first substrate having a flat first surface facing the liquid crystal material, a first transmissive electrode overlying the first surface, a first liquid crystal alignment film overlying the first transmissive electrode, the second substrate having a second surface facing the liquid crystal material, a second transmissive electrode overlying the second surface, a second liquid crystal alignment film overlying the second transmissive electrode, the second surface having a substantially sinusoidal cross-section having at least one substantially sinusoidal peak and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the optical data storage medium; an optical reception device for receiving a light beam from the optical data storage medium and providing a data signal responsive thereto.

Claim 32

An aberration compensation system comprising: a light source for providing a beam of light; a device for receiving an optical data storage medium; a focus device for focussing the beam of light to a focus point at a first and a second depth in an optical data storage medium, the focus device focussing the beam of light to the first depth without spherical aberration; an aberration compensator lens in optical communication with the focus lens, for receiving and passing the beam of light, the aberration compensator lens comprising a first and a second transmissive substrates, a device for maintaining the first and second substrates in a spaced apart relationship, a liquid crystal material located between the first and second substrates, the first substrate having a flat first surface facing the liquid crystal material, a first transmissive electrode overlying the first surface, a first liquid crystal alignment film overlying the first transmissive electrode, the second substrate having a second surface facing the liquid crystal material, a second transmissive electrode overlying the second surface, a second liquid crystal alignment film overlying the second transmissive electrode, the second surface having a substantially sinusoidal cross-section having at least one substantially sinusoidal peak and at least one substantially sinusoidal valley portion, the cross-section being substantially complementary to a wavefront aberration curve caused when the beam of light is focussed to the second depth in the optical data storage medium; an optical reception device for receiving a light beam from the optical data storage medium and providing a data signal responsive thereto.

Claim 33

The system of claim 28, wherein the liquid crystal material is comprised of a nematic liquid crystal.

Claim 34

The system of claim 28, wherein the liquid crystal material is comprised of a semantic liquid crystal.

Claim 35

The system of claim 28, wherein the first and second alignment films are comprised of polyvinyl alcohol

Claim 36

The system of claim 28, wherein the surface of the second substrate has a cross-section having a central sinusoidal valley portion and a sinusoidal peak portion on either side of the central sinusoidal valley portion.

Claim 37

The system of claim 28, wherein the device for maintaining the first and second substrates in spaced apart relationship comprises an epoxy layer.

Claim 38

The system of claim 28, wherein the liquid crystal material has a first and a second index of refraction, the first index of refraction being equal to the index of refraction of the second substrate.