Abstract: The part of the distributor electrode in the breakdown region has a resistance of at least 400 ohms per millimeter. The total resistance of the electrode is in the range of between 0.5 and 1.0 kilo-ohms. The material is a mixture of a resistive ceramic material and a finely dispersed additive of metallic conductivity. Arrangements for creating surface discharge gaps thereby slowing down the sparking process and decreasing interference are also illustrated.

Abstract: In order to improve the near-field illumination provided by motor vehicle headlights having a polarized light output, the headlight is provided with mirrors which intercept non-polarized light from the parabolic reflector and direct it through diffuser plates for near-field illumination alongside the central polarized beam. The rear surface of mirrors already present for bending the central polarized beams is made reflective and a second set of plane parallel mirrors is provided for bending the light reflected from the rear surfaces of the first set of mirrors back into the direction of the optical axis.

Abstract: 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.

Abstract: 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.