U.S. Philips Corporation

Dirk C Van Eck

Peter Coops

Willem G Opheij

Martinus P Bierhoff

Joannes H Sieben

Adrianus J Duijvestijn

Peter De Zoeten

Optoelectronic devices in which optoelectronic components comprising a diode laser are fastened on a carrier plate having good heat conduction, and in which the carrier plate is provided with connection conductors for the components which are separated from the carrier plate by an electrically insulating medium, are used inter alia in equipment for optical reading and/or writing of information carriers such as CD (audio) or CDROM. The known device is comparatively expensive, especially because of the necessity of using a special connector when a flexible connection is desired. According to the invention, the electrically insulating medium comprises a strip-shaped flexible foil which carries conductor tracks, extends over and beyond the carrier plate, is fastened on the carrier plate, and has a void above the carrier plate in which the diode laser is present. As a result, the device has a flexible connection possibility without a special connector being necessary, while in addition--as in the known device--a good alignment, listening, and heat removal of the diode laser are possible. The manufacture and modification of the device according to the invention are also simpler and cheaper. Preferably, the device comprises within the void also a photodiode and a monitor diode, while the components are screened by means of a cover which is fastened on the carrier plate and which comprises a window containing one or several optical gratings. Such a so-called LDGU (=Laser Detector Grating Unit) is particularly suitable for use in the equipment mentioned above. The invention also relates to a favourable method of manufacturing such an optoelectronic device.

Optoelectronic device and method of manufacturing same with an

An optical scanning apparatus, which includes a radiation source (7) supplying a scaning beam (b.sub.1), an objective system (8) for focusing the scanning beam (b.sub.1) to a scanning spot (S.sub.1) in an information plane (2) to be scanned, and a first diffraction element (9) for deforming the beam reflected by the informatin plane (2) in such a way that a focus-error signal can be derived therefrom. The apparatus also includes a second diffraction element (10) for forming two auxiliary beams (b.sub.2, b.sub.3) by means of which a tracking-error signal can be derived, which second diffraction element has such a size and is arranged at such position that the beams originating from the first diffraction element (9) do not traverse the second diffraction element.

Apparatus for optically scanning an information plane

Growing community of inventors

Nijmegen, Netherlands

Dirk C Van Eck