Abstract: An LED module comprising at least one blue LED and a color conversion layer that is applied thereto and emits a mixed light of the blue light of the LED and the converted spectrum of the color conversion layer. The color conversion layer has at least three different phosphors which at least partially convert the light of the blue LED into red, green, and yellow or yellowish-green light. The phosphor for conversion into red light is a doped nitride compound, preferably a nitridosilicate.

Abstract: An LED module comprises at least one LED chip emitting monochromatic light having a first spectrum, a platform on which the LED chip is mounted, a reflecting wall that is separate from or integrated into the platform and surrounds the LED chip on all sides, and a dispensed layer applied above the LED chip. The dispensed layer extends in a dome-shaped manner beyond the reflecting wall such that the following equation is satisfied: 0.1*b?h?0.5*b where h is the height of the dome-shaped dispensed layer, measured from the topmost point of the reflecting wall to the apex of the dome, and b is the diameter of the depression formed by the reflecting wall, measured as the distance from the central axis of the wall.

Abstract: The invention relates to a method for isolating 5-substituted tetrazoles of general formula (I) in which R represents a substituted biphenyl radical during which the ring closure, starting from a corresponding nitrile, is carried out in organic solvents while using alkali, alkaline-earth or organotin azides. The organic phases containing the nitrile and the tetrazol are firstly mixed with water while firstly forming three liquid phases, after which the aqueous phase containing the azide and the phase containing the nitrile are separated out, and the middle organic phase containing the tetrazol is subsequently processed. In the case of ester groups to be saponified, this phase is mixed with alkali lye, after which the organic phase is separated out and the aqueous phase is acidified or otherwise, this phase is immediately acidified and purified.

Abstract: A device for forming a tactilely readable display including Braille characters includes a planar display carrier wherein consisting essentially of a belt of flexible material which forms a closed loop and revolves about two rotating rolls. Circular openings are provided on an outer side of the belt loop, the inner side of the belt being provided with a multiplicity of recesses communicating with respective openings in the outer side of the belt. A steel ball may be lodged in each of the recesses, a portion of each ball protruding through the associated opening to form a spherical raster dot on the outer side of the belt. An upper portion of the belt passes over a contact plate, which forms a reading zone of the Braille display device, while a lower portion of the loop passes through a steel ball container in which all of the recesses become occupied by a respective ball.