Abstract: An optical system includes comprising a polarizing element in the form of a layer which comprises an isotropic material having a refractive index n.sub.i and an anisotropic material having refractive indices n.sub.a,e and n.sub.a,o. The refractive index n.sub.i is substantially equal to n.sub.a,e or n.sub.a,o. The optical system includes a retroflector for back-reflecting the polarization component diffused in the polarizing element.

Abstract: An electric lamp according to the invention comprises a lamp vessel (10) which is closed in a gastight manner, which has an end portion (11), and which surrounds a light source (12). The lamp vessel supports a cylindrical collar (30) with an axis (31) at its end portion (11). One or several projections (33a, 33b, 33c) of a first coupling member (30) which each grip into a respective recess (41a, 41c) of a second coupling member (40) couple the collar (30) to a mounting member (40) for fastening the lamp to a carrier. At least one of the coupling members (30) is made of an elastic material.

Abstract: A method of manufacturing metallic droplets (9), comprising the following steps:(a) providing a substrate (1) which is substantially transparent to radiation of wavelength .lambda., one face (1a) of the substrate (1) being provided with a metallic layer (3) which is partitioned into an array of lands (5);(b) directing a laser beam (7) of wavelength .lambda. through the substrate (1) onto a land (5), thereby causing rapid melting of the land (5) and its detachment from the substrate (1) in the form of a molten droplet (9). In a preferential embodiment of the method, the molten droplet (9) is "shot" onto a target substrate (21) before solidifying.

Abstract: The invention relates to a reflective flat-panel display device (1) comprising a display panel (3) which is suitable for modulating an illumination beam with image information. The display panel (3) comprises a diffusing liquid crystalline material (5) and a first and a second substrate (7, 9) enclosing the liquid crystalline material (5) and reflecting means which reflect light incident at an angle which is larger than a given angle of incidence .theta..sub.c. The device further includes an absorbing element (10) which absorbs light passed by the reflecting means.

Abstract: An optical scanning device can scan two types of record carriers each having a transparent layer with a different thickness, in which a focused radiation beam scans an information layer of the record carrier through the transparent layer. When scanning a first type of record carrier the best focus of the radiation beam is positioned on the information layer and when scanning a second type of record carrier the paraxial focus of the radiation beam is positioned on the information layer. The lens system focusing the radiation beam comprises an opaque ring between a transparent central area and a transparent annular area.

Abstract: A matrix display device having an array of picture elements (12) which each comprise a serial charge redistribution D to A converter circuit that includes two transistors (30, 31) and two capacitors (34, 35), at least one of which comprises an electro-optic, e.g. liquid crystal, display element, and which are driven by switching signals and digital data signals from a drive circuit (21, 25) via row and column address conductors (18, 19) respectively. The two transistors of a picture element are of complementary type, e.g. n and p TFTs, connected to the same row conductor and operable in sequence by the switching signal on the row conductor (18). The drive circuit (21) is consequently simplified and the vertical scan direction can readily be reversed.

Abstract: A method of separating semiconductor elements (2) formed in a wafer of semiconductor material (1). A score (8) is formed in a surface (3) of the wafer (1) through local evaporation of semiconductor material by heat originating from radiation (10). This radiation (10) is generated by a laser (11) and focused on the wafer (1) by an optical system (12). The wafer (1) is moved relative to the radiation (10) focused thereon along a path (9) which follows the score (8) to be formed. The radiation (10) of the laser (11) is focused on the wafer (1) in the form of at least two beams (14 and 15), the wafer (1) being moved relative to the beams (14 and 15) such that the beams (14 and 15) travel the same path (9) one after the other. A deeper score (8) can be formed than by an unsplit beam of the same energy as the two beams together.

Abstract: A discharge vessel with a ceramic wall is filled with inert gas and metal and is ignited and operated by an electronic circuit including a half bridge converter with an LC circuit which, when the lamp is not ignited, enters an oscillation state near a resonance frequency which lies near the third harmonic of the switching frequency of the half bridge converter. The vessel encloses a cylindrical discharge space of diameter D and length L, wherein L.ltoreq.D.ltoreq.1.2 L.

Abstract: A lever member is pivotable about a horizontal axis which is fixed to a frame defining a horizontal plane. A blade profiled to slide under a shingle is fixed to a front end of the lever member, and lifts the shingle when a rear end of the lever member pivots downward under action of a pneumatic cylinder. The cylinder is mounted horizontally toward the rear of the frame, oppositely from the front of the lever member. The cylinder pushes a transverse linkage member forward, which pulls on cables extending rearward from the linkage member thence upward around pulleys to the rear end of the lever member.

Abstract: A color control system for projection television displays having a projection lamp, a light valve and a device for varying the color of the light from the projection lamp, such as a color wheel. The color wheel driver provides an output signal which represents the position, that is the color, of the color wheel disposed in the lamp beam. The lamp driver varies the output power used to drive the lamp in response to the particular color of the color wheel disposed in the beam. If the projection lamp has a deficiency in a certain color the present system provides greater output power to the projection lamp during the presence of the filter for that color. A user input control provides for changing the tint of the system based on user preferences and/or any changes occurring in the color filters or projection lamp.

Abstract: In a method according to the invention, a capsule (20) having a glass wall (21) and containing mercury is positioned in a radiation-transmitting discharge vessel, after which the discharge vessel is provided with a rare gas and closed, means for maintaining an electric discharge are arranged in or adjacent the discharge vessel, and the capsule is opened by fusion after the discharge vessel has been closed in that the capsule is heated by irradiation (42) with a parallel beam of radiation through the wall of the discharge vessel. The wall of the capsule has for this radiation an absorption coefficient which amounts at least ten times that of the wall portion of the discharge vessel. The method according to the invention renders possible a comparatively simple lamp construction.

Abstract: In a method in which a top coating (2) on a relatively hard substrate (1) is patterned by means of a stream of kinetic particles while being masked by a mask (3), the substrate (1) is coated with a damping layer (4) of a ductile material before the top coating (2) is provided.

Abstract: The luminaire has a housing (1) with a light emission window (2), and side reflectors (5) and lamellae (7), which may constitute a louver (8), in the housing (1). The light emission plane (2) is closed during transport by means of a shaped plastic sheet (10), which has a base plane (11) and opposed walls (12) connected thereto. The shaped plastic sheet (10) enters the housing with its walls (12) and thereby keeps its position fixed. The shaped sheet (10) can easily be removed when there is no longer a risk of the louver (8) becoming polluted.

Abstract: A low-pressure mercury vapour discharge lamp according to the invention is provided with a radiation-transmitting discharge vessel (10) which encloses a discharge space (11) in a gastight manner and comprises mercury as well as a rare gas. Mercury is also present in a vapour pressure control member (21) which is in communication with the discharge space (11) during nominal operation. The discharge lamp has means (40) for maintaining a discharge in the discharge space (11). The vapour pressure control member (21) forms part of a mercury control member (20) which also comprises mercury transport control means (22) which limit the mercury transport from the discharge space (11) to the vapour pressure control member (21), at least while the lamp is out of operation, to such an extent that this transport is at most 5 ng/h.cm.sup.3, measured at room temperature and in the presence of a saturated mercury vapour in the discharge vessel, per unit volume of the discharge space.

Abstract: The electric lamp has a glass lamp vessel (1) having seals (3) from which an external metal wire (6) extends. A bare corrosion resistant contact wire (7), having a specific resistance of less than 0.8 .mu..OMEGA.m and a hardness of 50-300 HV is welded, e.g. butt-welded to the external metal wire (6). The contact wire (7) has an axial free end portion (8). An transversally extending intermediate portion (9) may be present between the seal and the free-end portion (8). The lamp allows secure electrical connections to a luminaire easily and rapidly to be made.

Abstract: Metal-oxide layers having a high .delta..sub.max, such as in particular magnesium-oxide layers, are provided on a glass substrate, such as a selection plate or a channel plate, of an electronic display device by means of a spray-pyrolysis process. To this end, a solution of a metal salt, such as Mg acetate, in ethanol or another (organic) solvent and/or water is sprayed onto a substrate which is maintained at a temperature of 350-550.degree. C. In a display device which is provided with such a layer on the bottoms and walls of the channels of the channel plate, a minimum transport voltage of 50-100V/cm is required.

Abstract: An electrodeless low-pressure discharge lamp according to the invention has a lamp vessel (1) which is closed in a gastight manner, which contains an ionizable filling, and which has a cavity (10). In the cavity (10) an elongate coil (2) is positioned with a primary and a secondary winding (21, 22, respectively) of an electrical conductor (20) around a coil former (3) which has a tip (30) which points into the cavity (10). The electrical conductor (20) from which the secondary winding (22) is formed extends from a first end (22a) of the secondary winding (22) facing the tip (30) into a recess (32) of the tip (30) of the coil former (3) and is clamped therein. The first end (22a) of the secondary winding (22) can be easily fastened in this manner.

Abstract: Display device (1) comprising an illumination system (3) having a radiation source (17; 31, 35) for supplying a radiation beam. The display device (1) also comprises a diffusing display panel (5). This panel (5) consists of an optically active diffusing medium (7) which is switchable between a transparent, polarization-maintaining state and a diffusing, depolarizing state for the radiation beam. The medium (7) is present between a first polarizer (9) having a first state of polarization and a second polarizer (11) having a second, complementary state of polarization. At least the first polarizer (9) is a reflecting polarizer and polarization-converting means (10) are arranged at a side of the first polarizer (9) facing away from the display panel (5).

Abstract: A luminescent screen includes a luminescent zeolite containing rare earths, such as terbium (Tb), and europium (Eu), and an oxide of a transition metal, such as, molybdenum (Mo), tungsten (W), niobium (Nb), and tantalum (Ta). It was found that a zeolite containing both terbium, and tungsten oxide had an absorbability that was approximately 60 times as high as that of a zeolite containing only terbium, thus increasing the luminescent efficiency of the zeolite.

Abstract: Polarizing element having a first layer and a second layer. When an unpolarized light beam is incident on the element, the direction of at least one of the polarization components of the unpolarized beam will be influenced by the first layer. These polarization components have different directions of polarization. The second layer influences the direction of a polarized beam incident thereon. A polarization-rotating layer is present between the first layer and the second layer. An unpolarized beam can be substantially completely converted into a polarized beam having mainly the same direction of polarization.