Siemens Aktiengesellschaft

Patent-treuhand-gesellschaft Fuer Elektrische Gluehlampen Mbh

Bsh Hausgeraete Gmbh

Siemens Aktiengesellscaft

Osram Gesellschaft MIT Beschrankter Haftung

Wammes Und Partner Gmbh

As² Alternative Solutions Gmbh

Wammes & Partner Gmbh

Hitzschke, Lothar

Vollkommer, Frank

Klaus Wammes

Frank Vollkommer

Lothar Hitzschke

Michael M&auml;rz

Jochen Murr

An optical arrangement includes at least the following components which are arranged along an optical axis: a light source for polarized light; a layer arrangement, which, viewed in the viewing direction of a viewer, includes at least one polarization filter and an optical retardation layer behind the polarization filter. The polarization filter abuts the retardation layer free of gaps. An interstice is located between the light source and the layer arrangement. The interstice has a volume about the optical axis, that is surrounded by optically impermeable and internally non-reflecting, but absorbent peripheral surfaces. In the interstice, there is at least one semi-permeable boundary surface which is permeable to the light emitted by the light source and is at least partially reflective for light that is incident in the opposite direction.

Optical arrangement for improving the display quality of a display

In a night vision goggle compatible color liquid crystal display, liquid crystal cells (and) are arranged in a matrix in which three adjacent liquid crystal cells are respectively provided with a red, green, and blue filter. The liquid crystal cells are driven by drive circuit (). The drive circuit () is controlled by a control device () with red, green, and blue pixel information. The brightness of a backlight source of the color display can be switched from a high value in a daytime operation to a low value for a nighttime operation. To optimize the night vision goggle compatible color liquid crystal display, the control device () switches off the driver of the liquid crystal cells with the red filters during the nighttime operation.

Liquid crystal color display suitable for night-sight glasses

A lighting unit () preferably providing backlighting for a flat display device () and operating substantially in a vertical working position. The lighting unit () includes lamps (), which are in thermal contact with a heat-conducting wall () of a hollow box (). The lamps () make thermal contact with the heat-conducting wall () on the side opposite the light-emitting side of the lighting unit (). The hollow box () is provided with a rear wall () that runs essentially parallel to the heat-conducting wall () and has openings () which are distributed across the area thereof. A top sidewall () and a bottom sidewall () are provided with additional openings () in zones that lie closer to the rear wall (). Preferably, the sidewalls do not have openings in zones located closer to the heat-conducting wall () than the additional openings ().

Lighting unit for flat panel display device

A substantially U-shaped gas discharge lamp ( &prime;), containing mercury for the gas discharge, is connected to a high-frequency driver circuit ( &prime;). To ensure that the gas discharge lamp operates with minimum loss and maximum light yield, the respective output terminals ( &prime;) of the high-frequency driver circuit are not electrically grounded and the central section ( &prime;) of the gas discharge lamp is capacitively coupled to an electric ground. A substantial reduction of lamp current in the central section is ensured, thus lowering thermal production in the central section of the gas discharge lamp. Accordingly, the central section becomes the coldest place in the gas discharge chamber and the place where condensation of the mercury occurs. The mercury vapor pressure can thus be regulated and the light yield optimized.

Illumination unit having at least one essentially U-shaped gas discharge lamp

In an active matrix liquid crystal display, pixels are arranged in rows and columns of a matrix and are controllable via row electrodes and column electrodes. To improve and to expand the possibilities of image rendering without increasing the number of rows and columns to be controlled, the pixels are divided into sub-pixels with corresponding sub-pixel electrodes, each of which is connected to the column electrode assigned to the pixel via controllable switches. On the control side, the controllable switches are connected to the row electrode assigned to the pixel via pixel control unit which is common to them. From a control signal supplied to it via the row electrode the pixel control unit generates locally and chronologically different turn-on signals for the various switches so that they switch chronologically successive different gray-scale levels of a gray-scale signal present at the column electrode through to the sub-pixel electrodes.

Active matrix liquid crystal display

In an active matrix liquid crystal display having liquid crystal cells arranged in rows and columns. One side of the liquid crystal cells is in contact with a common reference potential and it being possible to switch gray-scale signals through on the other side. In order to increase the voltage range within which the liquid crystal cells can be operated without distortion of the image rendering, a correction device is provided which distorts the gray-scale signals reaching the liquid crystal cell based on information concerning the typical dependence between the optical transparence of the liquid crystal cells and the voltage applied to them and as a function the potential difference between the gray-scale signals and the reference potential in such a way that an at least approximately linear relationship results between the optical transparence of the liquid crystal cells and the undistorted gray-scale signals.

A description is given of an operating method for a discharge lamp with dielectrically impeded discharges and also a corresponding ballast and illumination system. The invention is directed at withdrawing the external lamp voltage across the discharge lamp in order to produce a back ignition in the lamp by virtue of an internal counterpolarization. The back ignition improves the efficiency of the lamp operation and makes it possible to construct a very small, lightweight ballast.

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Bechtheim, Germany

Klaus Wammes