Robert Boschgmbh

Karl Kerner

Ernst Zehender

Bernhard Blaich

Ernst Linder

Richard Zechnall

Gotthold Raabe

Helmut Stein

Albert Schmid

Rudi Socknick

The present invention provides a process for preparing silicon oxide layers on a substrate, and particularly on metal, having improved corrosion-protective properties. This is accomplished by making the silicon oxide protective layer hydrophobic, preferably by incorporating therein hydrophobic organosilicon residues. The protective layers are preferably prepared by vapor deposition in a vessel containing silicon and/or silicon oxides in the gasous form, oxygen, and a organosilicon compound containing at least one hydrophobic group bonded to the silicon.

Silicon oxide coated metal having improved corrosion resistance

The reflectors, for example for automotive vehicle head lamps are reflectorized by evaporating aluminum thereon in a vacuum vessel at a vacuum of about 10.sup.-7 bar; thereafter, and without removing the reflectors, a gaseous monomer is introduced raising the pressure to about 5 .times. 10.sup.-6 bar to deposit a protective layer by polymerization from the gaseous phase. The monomer gases, preferably, are low molecular weight siloxanes having methyl-, vinyl- or phenyl groups, preferably hexamethyldisiloxane (HMDS), or methyl-, vinyl- or alkoxy silanes, preferably vinyltrimethylsilane (VTMS), polymerization being accelerated and ensured by an electrical discharge generated within the vessel by a heated electron emitter placed at a negative voltage with respect to the reflector blanks. After polymerization, the layer is rendered hydrophilic by treatment with oxygen at a pressure of about 10.sup.-2 to 10.sup.-3 m bar to form an organosilicon polymeric protective layer which is inherently hydrophobic and has a hydrophilic surface.

Method to apply a protective layer to the surface of optical reflectors,

A polarizer structure for a headlight includes an interference-type polarizer followed by an absorption-type polarizer. The interference-type polarizer in one form of the invention is constituted by rectangular plate polarizing sections in a zigzag arrangement, so that the apex angle formed by adjacent polarizing sections is always 90.degree. while the angle of each polarizing section to the optic axis is 45.degree.. In another form of the invention, the polarizer sections are arranged in a diverging louvre arrangement provided with reflecting layers between the polarizing sections, both the polarizing sections and the reflecting layers at an angle of 45.degree. with the optic axis.

Polarized light beam source in a vehicle headlight

Growing community of inventors

Stuttgart, Germany

Karl Kerner