Abstract: The method of producing optical radiation and a discharge lamp for that purpose pertain to electrical technology, specifically to methods of producing radiation in the visible spectrum resulting from electrical discharge in gas, and to low-pressure discharge lighting lamps of various types. The proposed method of producing optical radiation, and the associated discharge lamp, extend the available range of environmentally clean lighting systems. The method involves creating a gas discharge in an inert gas atmosphere with a radiating additive in an optically transparent tube. A novelty of the method lies in the use as a radiating additive of the HO radical. The discharge lamp comprises an optically transparent tube (1) filled with an inert gas and a radiating additive. Also novel is the use as a radiating additive of an HO source obtainable from water or group II metal alkalis.

Abstract: A high-pressure discharge lamp provided with an outer bulb enclosing a discharge tube accommodates a transformer having primary winding which forms part of a current conductor to one of the main electrodes of the discharge tube. The secondary winding is coupled to an ignition electrode of the discharge tube. Higher ignition voltages can be achieved without increasing the voltage pulse on the outside contacts of the lamp.

Abstract: The electric lamp has a quartz glass lamp vessel (1) having first and second neck-shaped portions (2, 3) with first and second seals (4, 5). Current supply conductors (6, 7, 8; 9, 10, 11) consist of a metal foil (7, 10) embedded in the respective seal (4, 5), an inner (6, 9) and an outer current wire (8, 11) connected hereto. A seal ends with a closed fracture surface (14) through which an outer current wire (8, 11) extends. Favorably, the edge (13) of the fracture surface (14) has some small indentations (16) adjacent the origin of the fracture (19). The total length of the lamp is about 2 mm less than that of its conventional counterpart.

Abstract: Metal halide lamp radiates light with a color temperature T.sub.c of between 3900 K and 4200 K and with a general color rendering index R.sub.a .gtoreq.90. The ionizable metal halide filling comprises between 30 and 50 mole % CaI.sub.2. The lamp has a limited crest factor, and accordingly a long useful life.

Abstract: The invention relates to an illumination system (1) comprising, in this order, a radiation source (5) and an integrator system (11). First reflecting means are present in the exit plane (25) of the integrator system (11) and second reflecting means in the form of a reflective polarizer (29) are further present in the illumination system (1). An optical system (23) for at least partly imaging the exit surface of the integrator system (11) via the second reflecting means on the first reflecting means is present between the first reflecting means and the second reflecting means. Moreover, polarization-converting means are present between the first and the second reflecting means.The invention also relates to an image projection device and to a presentation system provided with such an illumination system.

Abstract: A flat glass panel 1 for a picture display device of the flat type, is formed by two glass cover plates (3, 5) with at least one glass plate (4, 4', 4", . . . ) between them, and a vitreous frit (8) between the cover plates along the outer edges of the cover plates so as to obtain a box-type glass panel in which a channel structure is present. After heating to the melting temperature of the frit (8), the panel is cooled down to a transitional temperature of the frit, while the space between the cover plates is partly exhausted during the cooling-down phase at a temperature which lies between the melting temperature and the transitional temperature of the frit. Then the temperature is kept constant at approximately the transitional temperature until the frit has become undeformable, said space (13) between the cover plates (3, 5) being fully evacuated then. Finally, cooling-down continues to room temperature, and the space (13) inside the panel is hermetically sealed off.

Abstract: The illumination system (21) includes two radiation sources (23, 25) and an optical system for concentrating the radiation into beams, a common polarizing system (11) for splitting the beams (b.sub.I, b.sub.II) into linearly polarized sub-beams, and at least one polarization-rotating element (35). The polarizing system includes at least one optically transparent plate (11) having a refractive index n.sub.0 and a first face and a second face. At least one of these faces is provided with an optically thin layer having a refractive index n.sub.1 which is larger than n.sub.0. The light path of the sub-beams whose directions of polarizations are not to be converted incorporates a reflector (41, 43) for reflecting the sub-beams into the same direction of propagation as that of the other sub-beams.

Abstract: A circuit arrangement is provided for controlling an electric motor (2), in particular a three-phase, three-strand motor, which is coupled to an intermediate circuit voltage (4) via a DC/AC converter (3) having three DC/AC converter branches (7,8,9). A measuring signal (i.sub.b1,i.sub.b2,i.sub.b3) which is proportional to the branch current is derived from each of the DC/AC converter branches (7,8,9), and a control signal (I.sub.pn), which is substantially proportional to the total value of the strand currents (i.sub.1,i.sub.2,i.sub.3) of the motor, is derived from these measuring signals (i.sub.b1,i.sub.b2,i.sub.b3).

Abstract: An electrical device comprising an array of pixels has a plurality of panels 10, 20, 30, each having a respective sub-array of pixels 11. Each panel 10, 20, 30 is associated with an array 40 of lens elements 42, which may be associated with a group of one or more pixels of the sub-array. The lens elements 42 are arranged with a pitch which is greater than the pitch of the associated group of pixels, so that a diverging image is produced, enabling tiling of panels of an image sensor or of a display device.

Abstract: The capped electric lamp has a cap (3) secured to a sealed lamp vessel (1). The cap (3) has a housing (10) of metal sheet, having a cylindrical shell (11) and remote from the lamp vessel (1) an integral base (13) having an opening (14) therein. A cavity (15) is formed in the base (13) by deforming the base (13) in outward direction. An insulator plate (16) carrying a contact pin (4) and covering the opening (14) is secured in the cavity (15) by means of a folded seam (17) in the housing (10). The seam (17) presses against a side (18) of the insulator plate (16) which faces the lamp vessel (1).

Abstract: A lens plate integrator includes first and second lens plates which transmit light from a light source on an optical path to a projection plane. Each lens plate includes corresponding first and second groups of lens elements; light from the first group of the second plate is focused on a projection face in the projection plane, while light from the second group of the second plate is focused in front of or behind the projection plane and only partially illuminates the projection face.

Abstract: Electrical actuator having a stator body and a rotor body which is pivotable iN the stator body through an angle of rotation. The actuator further comprises energizing means for exerting an electromagnetic torque on the rotor body and a control unit for controlling the angle of rotation. The control unit has a cascade control structure with a first control member for converting an electrical input signal corresponding to a required angle of rotation into an electrical intermediate signal corresponding to a required electromagnetic torque to be exerted on the rotor body and with a second control member for converting the intermediate signal into an output signal corresponding to a required electrical current through the energizing means. The first and second control members allow for specific intermediate calculations of the required electromagnetic torque and the required current, whereby the response time and accuracy of the control unit are improved.

Abstract: A low-pressure mercury discharge lamp is provided with a discharge vessel (1) which encloses a discharge space (2) in a gastight manner and in which a filling including mercury is accommodated. The lamp is provided with means (3a, 3b) for maintaining an electric discharge in the discharge space. The discharge vessel is provided with a luminescent layer (5). The lamp generates light during operation with a spectrum which is substantially composed of radiation in a first wavelength region from 590 to 630 nm, a second wavelength region from 520 to 565 nm, and in a third wavelength region from 430 to 490 nm. The radiation in the wavelength interval from 590 to 600 nm accounts for at least 50% of the power of the radiation in the entire first wavelength region. A preferred embodiment of the lamp includes a luminescent material that complies with the formula M1.sub.x M2.sub.(1-x-y) BO.sub.3 :Eu.sup.3+.sub.

Abstract: A light-transmitting discharge vessel (10) encloses a discharge space (11) in a gastight manner. The discharge space comprises mercury as well as one or several inert gases. The lamp is in addition provided with an electric coil (20) for generating a high-frequency magnetic field in the discharge space. The discharge lamp is provided with an auxiliary amalgam (40) which is provided on an elongate carrier (41) which is mechanically coupled to a tube (50) which issues into the discharge space. The auxiliary amalgam (40) covers the carrier (41) at least substantially entirely.

Abstract: A metal alloy having an intrinsically low TCR, and which preferably comprises a metal oxide and forms part of the resistance material in a quantity of 15-60 vol. %. The best results are achieved with a resistance material which comprises an alloy of CuNi as the metal alloy and SiO.sub.2 as the high-ohmic component. The resistors exhibit a relatively high resistance value as well as a relatively low TCR value.

Abstract: A lighting unit according to the invention comprises a supply unit (1) and a low-pressure mercury discharge lamp (2). The low-pressure mercury discharge lamp has a light-transmitting discharge vessel (3) which is provided with a luminescent layer (3) on an inner surface and which encloses in a gastight manner a discharge space (4) which is provided with a filling comprising mercury and one or several rare gases. A first (5a) and a second electrode (5b) are arranged in the discharge space, each comprising a coiling of a metal wire coated with one or several electron-emitting metal oxides. Each electrode is electrically connected to a respective current supply conductor (6a, 6b) which extends to outside the discharge vessel (3). The current supply conductors are electrically connected to the supply unit outside the discharge vessel, the unit ignites the low-pressure mercury discharge lamp in the state upon switching-on.

Abstract: HID lamp has a U-enhancer connected between first and second leads for an arc tube. The UV-enhancer has a quartz envelope containing an electrode connected to the first lead, and is surrounded by a metal ring which is spaced from the envelope by a sleeve of borosilicate glass. The ring is capacitively coupled to the envelope and is electrically connected to the second lead, which may also support the sleeve.

Abstract: A method of producing a surfacial marking (11) on a surface (1b) of a body (1) of transmissive material, whereby use is made of a laser beam (5) having a wavelength .lambda. to which the material is substantially transparent, which method comprises the following steps:(a) providing a layer (3) of assistant material against the surface (1b), which assistant material is absorptive at the wavelength .lambda.;(b) directing the laser beam (5) through the body (1) onto the layer (3), so as to locally heat and ablate the layer (3).

Abstract: A quartz glass vessel having mutually opposed first and second neck-shaped portions is heated over the first neck-shaped portion while flushing the vessel with gas, then pinched over an external current wire and collapsed over a metal foil by means of reduced pressure to form a seal. The second neck-shaped portion may also be collapsed over a metal foil by reduced pressure in the lamp vessel to form a seal. The seals are preferably shaped to form flat external surfaces.

Abstract: The high pressure discharge lamp has a discharge vessel (1) mounted in an outer envelope (4) in which an oxygen dispenser (30) is disposed. The oxygen dispenser (30) contains silver oxide and may be disposed at a location where it obtains a temperature of at least 340.degree. C. during operation of the lamp, at which temperature the oxide is decomposed and oxygen is released. The deposit of black coatings originating from hydrocarbon contaminations is thereby prevented.