Thomson-csf

Jean-Pierre Le Merer

Dominique Leterme

Claude Bricot

Patrick Volleau

Michel Chaboche

Jean-Claude Lehureau

Michel Thirouard

Louis Arquie

The optical head in the recording-reading device of a data carrier comprises a semiconductor laser source. A lens makes it possible to focus the beam from this source on to the data carrier via a reflecting or deviating mirror. According to the invention the rotation axis of this mirror is in the plane of the entrance pupil and of the focus of the focusing lens.

Optical head in a device for recording and reading a data carrier

An optical head is provided for an information carrier recording-reading device. Such an optical head comprises a pivoting mirror for reflecting the light towards the data carrier. According to the invention, this pivoting mirror is mounted on a pivoting seat having a sliding surface and resting on the sliding surface of the cradle shaped base. Said mirror is mounted on the seat so that the center of curvature of the sliding surfaces is in the reflecting plane of the mirror. Adjustment of the orientation of the mirror is thus made easy.

Optical recording-reading head using an adjustable mount for pivoting

The optical head in the recording - reading device of a data carrier comprises a semiconductor laser source. A lens makes it possible to focus the beam from this source on to the data carrier via a reflecting or deviating mirror. According to the invention the rotation axis of this mirror is in the plane of the entrance pupil and of the focus of the focusing lens.

The optical head in a data carrier recording-reading device comprises a semiconductor laser source. A lens makes it possible to focus the beam from this source. A polarization beam splitter makes it possible to deflect the beam reflected by this carrier towards a group of photodetectors. According to the invention the splitter is an isosceles prism, which serves as an anamorphotic-splitting means. A quarter-wave plate is bonded to one of the faces of the prism. A planoconvex lens can also be bonded to the other face of the prism upstream of the photodetector.

Optical head in a recording and reading device for a data carrier

An optical device for forming a stigmatic image of a laser source positioned at a predetermined point is intended to illuminate a reflecting surface while also providing a separation between the beam emerging from the source and the beam reflected from the surface. The device comprises a cube placed against a converging lens, the dimensions of the assembly thus formed being such that the cube face remote from the lens passes through a Weierstrass point of the spherical refracting surface formed by the lens. The laser source is positioned at the Weierstrass point. The cube is formed by two prisms cemented together, the interface being treated so as to have a polarization-separating effect.

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Paris, France

Jean-Pierre Le Merer