Abstract: The present invention discloses to a high refractive index polysiloxane (co)polymer comprising refractive index modifying groups chemically bonded in clustered configuration to the polysiloxane backbone. The invention also discloses methods for the preparation of such high refractive index polysiloxane (co)polymers. A polysiloxane according to the invention is very suitable for use as a material for the production of intra-ocular lenses.

Abstract: A projection system is provided with a square-wave current light source and a color wheel with differently colored segments. The lifetime of the light source is long since the square-wave current constantly changes polarity a constant power is supplied to the light source and, before changing polarity, a current pulse is each time provided, driving the square-wave current to a predetermined strength which is larger than the current strength in between the current pulses. In the course of time, the amount of power in the current pulses increases relative to the amount of power in the current in between the current pulses. By controlling the timing of occurrence of the current pulses to constantly coincide in time and, on average, an equal number of times with all colors of the color wheel, the position of the white color point is independent of the period of time of use of the light source.

Abstract: A projection system is provided with a square-wave current light source and a color wheel with differently colored segments. The lifetime of the light source is long since the square-wave current constantly changes polarity a constant power is supplied to the light source and, before changing polarity, a current pulse is each time provided, driving the square-wave current to a predetermined strength which is larger than the current strength in between the current pulses. In the course of time, the amount of power in the current pulses increases relative to the amount of power in the current in between the current pulses. By controlling the timing of occurrence of the current pulses to constantly coincide in time and, on average, an equal number of times with all colors of the color wheel, the position of the white color point is independent of the period of time of use of the light source.

Abstract: A connecting mechanism for connecting a functional part of a mobile unit to a basic unit. The mobile unit consists of a mobile bottom part provided with compression springs on which the functional part rests. The functional part is provided with connecting elements which can cooperate with connecting elements on the basic unit with the compression springs compressed. The connecting elements are formed by a hook and a roller which form an arcuate contact interface at a lower portion of the units, and by confronting vertical contact surfaces at the top of the units.

Abstract: The present invention relates to a hydraulic jack with a base plate on which are attached a pump cylinder, a jack cylinder, and a reservoir concentrically surrounding the jack cylinder, the reservoir being connected to the pump cylinder by means of a first passage, passing through the base plate, and a first nonreturn valve which enables hydraulic medium to flow from the reservoir on pumping, the pump cylinder being connected to the jack cylinder by means of a second passage, passing through the base plate, and a second nonreturn valve which enables hydraulic medium to flow from the pump cylinder on pumping, and the jack cylinder being connected to the reservoir by means of a relief passage and a blocking member including an adjustable bolt.