U.S. Philips Corporation

Koninklijke Philips Corporation N.V.

Asml Netherlands B.v.

Jan Peter Baartman

Jan Willem Aarts

Bernardus Hendrikus Wilhelmus Hendriks

Gerard E Van Rosmalen

Wouter Onno Pril

Allard Eelco Kooiker

Suzanne Johanna Antonetta Geertruda Cosijns

Bryan Tong-Minh

Johannes Theodorus Adrianus Van De Veerdonk

An encoder includes an optical component and an enclosing device having a first surface portion and a second surface portion. The first surface portion is arranged to receive from an ambient environment a first radiation beam. The second surface portion is arranged to receive from the ambient environment a second radiation beam. The optical component is arranged to combine the first and second radiation beams. The enclosing device is arranged to propagate the first radiation beam along a first path. The first path is between the first surface portion and the optical component. The enclosing device is arranged to propagate the second radiation beam along a second path. The second path is between the second surface portion and the optical component. The enclosing device is arranged to enclose a space, so as to isolate the first path and the second path from the ambient environment.

Encoder, position measurement system and lithographic apparatus involving an enclosing device

An optical scanning device includes a radiation source; an optical lens system with an optical axis for focusing a radiation beam supplied, in operation, by the radiation source into a scanning spot on an information carrier, the lens system including a housing, a first lens which is secured in the housing in a fixed position, and a second lens which, viewed in a direction parallel to the optical axis, is elastically suspended in the housing; a first actuator for displacing the lens system in a direction parallel to the optical axis; a first control unit for controlling the first actuator by means of a first control signal; a second actuator for displacing the second lens relative to the first lens in a direction parallel to the optical axis; and a second control unit for controlling the second actuator by means of a second control signal, and in which during operation, the first control unit also controls the second actuator by means of a third control signal which is proportional to the first control signal.

Optical scanning device with parallel-controlled actuators

An optical lens system including: a first lens including a more than half part of a substantially spherical first lens body having a first diameter and a substantially flat first boundary surface; a second lens including a more than half part of a substantially spherical second lens body having a second diameter and a substantially flat second boundary surface, the second diameter being smaller than the first diameter; and a lens holder comprising a first and a second mount for, respectively, the first and second lens, wherein the first an the second mounts comprise, respectively, a first and a second circular cylindrical inner wall having a common center line, a diameter of the first inner wall and a diameter of the second inner wall being substantially equal to, respectively, the first and the second diameters.

Optical lens system comprising two more than half-spherical lenses

An optical player includes an optical scanning device. The scanning device includes an optical lens system for focusing a light beam into a scanning spot on a track of an information carrier. The scanning device includes a first actuator for displacing the lens system parallel to an optical axis for focusing the light beam on the information carrier. The lens system includes a main lens or objective lens and an auxiliary or solid immersion lens, providing the lens system with a large numerical aperture, so that the scanning device is suitable for scanning information carriers with a high information density, such as, for example, high density compact discs. The auxiliary lens is secured in a fixed position to a housing of the lens system, while the main lens is suspended in the housing in a direction parallel to the optical axis by an elastically deformable mounting unit. The lens system includes a second actuator for moving the main lens relative to the auxiliary lens in a direction parallel to the optical axis for compensating for spherical aberration in a transparent protection layer of the information carrier. Thus, the necessary power of the first actuator is limited considerably.

Optical scanning device comprising a main lens and an auxiliary lens

In an optical recorder and/or player the lens system of the scanning device focuses the light beam into a scanning spot on the information carrier. The lens system includes a main or objective lens and an auxiliary or solid immersion lens to provide the large numerical aperture required for scanning information carriers with a high information density, such as high-density compact discs. At least one lens, in particular the main lens, is suspended in a housing in a direction parallel to the optical axis of the lens system by two elastically deformable mounting elements. When viewed parallel to the optical axis, the mounting elements are distal from each other, and each allow tilting movements of the lens about tilt axes perpendicular to the optical axis, and are substantially undeformable in directions perpendicular to the optical axis. During manufacture of the lens system, the lenses are aligned relative to each other by shifting at least one of the mounting elements in directions perpendicular to the optical axis. The lenses may be positioned parallel to each other by shifting one of the mounting elements in a direction perpendicular to the optical axis, and centered relative to each other by shifting the non-suspended lens in a direction perpendicular to the optical axis. Thus, allowing accurate alignment of the lenses relative to each other using a simple manipulator with limited positioning possibilities.

Method of manufacturing a lens system comprising two lens elements

An optical scanning device includes an optical lens system for focusing a light beam into a scanning spot on an information carrier. The lens system includes a housing containing a main or objective lens and an auxiliary or solid immersion lens with a ring-shaped holder. The lens combination provides a large numerical aperture, so that the scanning device is suitable for scanning information carriers with a high information density, such as high-density compact discs. The lens system also includes an actuator for displacing the lens system and for displacing the auxiliary lens with respect to the main lens in a direction parallel to an optical axis of the lens system for compensating for spherical aberration in a transparent protection layer of the information carrier. The actuator includes a ring-shaped magnetic closing yoke which is secured to a housing and includes two ring-shaped permanent magnets which, viewed parallel to the optical axis, are secured next to one another to the closing yolk. The magnets are magnetised in mutually opposite radial directions relative to the optical axis. The actuator also includes two ring-shaped electric coils, which are secured to a ring-shaped holder of the auxiliary lens. The coils are arranged, viewed parallel to the optical axis, next to one another and opposite the two magnets, and the coils are wound in mutually opposite directions. In this manner, the actuator of the lens system has a favorable ratio between its dimensions and its electromagnetic force, so that the dimensions and weight of the actuator necessary for obtaining a predetermined electromagnetic force can be limited.

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Eindhoven, Netherlands

Jan Peter Baartman