Abstract: An electrodeless low-pressure discharge lamp is provided with a lamp vessel which is closed in a gastight manner, which surrounds a discharge space, and which contains a filling of mercury and rare gas. The lamp vessel has a cavity and a collar where the cavity is open towards the exterior, an electric coil being accommodated in the cavity and support with an amalgam being arranged in the discharge space. The collar is made of metal and the support of the amalgam is fastened to the collar. This construction counteracts degeneration of the amalgam.

Abstract: A picture display device is disclosed having an illumination system and a picture display panel which is provided with a matrix of n panels and has a pitch p.sub.p. The device further has a projection lens system for projecting light modulated by the picture display panel to form an image. The illumination side of the picture display panel is provided with a microlens array having m microlenses and a pitch p.sub.m. The illumination system includes N illumination elements which are arranged in an array and have pitch p.sub.1. The illumination elements generate light simultaneously. Moreover, N<<m,n and p.sub.1 >>p.sub.m, p.sub.p.

Abstract: The electric reflector lamp has a reflector body with a neck. A lamp vessel containing an electric element is secured in the reflector body, held by a mounting member which has a securing portion. A lamp base is secured around the neck. The mounting member has a circumferential wall which surrounds the neck and which has relief cooperating with relief of the neck so as to couple the circumferential wall to the neck. Elastic elements of the circumferential wall seize in the recesses in the ceramic lamp base so as to secure the base. The reflector lamp is readily assembled using a small number of components.

Abstract: The high pressure discharge lamp has refractory electrodes each having a top and a winding of refractory metal wire, which has turns and is, in an area thereof remote from the top, secured to the electrode. The turns of the winding are made to have torsion. Thereby an accurately defined position with respect to the top of the electrode is obtained. The direction of the torsion is opposite to the direction of the turns, which causes neighbouring turns to press one against the other.

Abstract: The capped electric lamp has a quartz glass lamp vessel (1) having first and second neck-shaped portions (2,3) with respective seals (4,5). A glass envelope (9) surrounds the lamp vessel and is secured thereto. A clamping member (20) surrounds the envelope in a clamping manner. A fixation member (32) of a lamp cap (30) is welded to the clamping member. The clamping member (20) is an undulated metal body, the crests of its creases constituting regions (22) which are spaced from the envelope (9) and in which welds to the fixation member (32) are made. Its troughs constitute clamping zones (21) which hold the envelope. The clamping member (20) allows for the application of a relatively wide envelope (9), which may enter the lamp cap (30).

Abstract: The invention relates to a high-pressure discharge lamp provided with a discharge vessel which encloses a discharge space, which has a ceramic wall, and which is sealed at one end by means of a projecting ceramic plug which encloses with clearance a current supply conductor to an electrode arranged in the discharge vessel and is connected to said conductor adjacent an end facing away from the discharge space in a gastight manner by means of a melting-ceramic connection. According to the invention, at least an end portion of the ceramic plug situated near the end facing away from the discharge space is impermeable to light.

Abstract: The capped high pressure discharge lamp includes a light source (1) having a lamp vessel (1') with a first neck shaped portion (2) to which a lamp cap (30) is fixed. A connection conductor (7) runs alongside the discharge vessel to connect a second current supply conductor (5) extending from a second neck shaped portion (3) to a second contact member (36) of the cap. The lamp vessel (1') is contained by a tubular outer envelope (20), which is filled with air and does not envelope the connection conductor (7). The outer envelope (20, 50) has a narrowing portion (21, 52, 51) which encloses the second current supply conductor (5) or a neck shaped portion (2, 3). The outer envelope is maintained. The lamp is of a simple construction which allows for optimizing the light output or the temperature of the lamp vessel.

Abstract: The signaling system contains a low-pressure rare gas discharge lamp having a tubular lamp vessel provided with electrodes. The lamp is accommodated in a housing having a light-emission window and light-reflecting means. The housing has a light-reflecting inner surface reflect light and an elongate converging lens, closing the light-emission window. The housing may have a niche in which the lamp is partially recessed countersunk and in which the lamp may be secured by an adhesive.

Abstract: An illumination system comprises a radiation source and a broadband, cholesteric polarizer. Such a polarizer includes a layer of a polymeric material having a cholesteric ordering, the material being ordered such that the axis of the molecular helix is oriented transversely to the layer. The broadband character of the polarizer is obtained by increasing the pitch of the molecular helix from a minimum value at a first surface of the cholesteric layer to a maximum value at the second surface of the layer. The polarizer must be positioned in the illumination system in such a manner that the second surface of the cholesteric layer faces the radiation source. By virtue thereof, the illumination system attains a surprisingly low viewing-angle dependence of the brightness and the colour. This property is further improved by using a quarter lambda plate having a negative an isotropy in the refractive index.

Abstract: A wide angle objective system is described for, inter alia CCD cameras, which system is compact, inexpensive and satisfactorily corrected. It comprises a front meniscus lens (L.sub.1), a thick convex-concave central lens element (L.sub.2) and a biconvex lens element (L.sub.3), the two last-mentioned elements preferably being cemented together, the pupil (P) being present at the area of the exit surface (4) of the second lens element and the first and the third element (L.sub.1,L.sub.3) being made of, for example PMMA and the second element (L.sub.2) being made of, for example PC.

Abstract: A picture tube and lens system are combined to form a picture display device for use in a projection device. The lens system is mounted in an extension of the tube envelope.

Abstract: Picture display device (1) comprising an illumination system (3) and a picture display panel (7) which is provided with a matrix of pixels. The picture display panel (7) may be a transmissive or a reflective picture display panel. In the case of a transmissive picture display panel, a first microlens array (19) is arranged at the illumination side of the picture display panel (7), and a second microlens array (21) is arranged at the side of the picture display panel (7) remote from the illumination system (3). In the case of a reflective picture display panel, the picture display device (1) comprises only one microlens array (61) which is arranged between the illumination system (3) and the picture display panel (7). In both cases, the number of lenses (23, 25; 63) of a microlens array (19, 21; 61) corresponds to the number of pixels (27) of the picture display panel (7).

Abstract: The electric lamp has a lamp vessel (1) having first (2) and second (3) opposed necks, each having an end portion (4). Current conductors (7) extend from an electric element (5) having an axis (6) through a respective neck (2,3) and end portion (4) to the outside. Mounting members (10, 11) are secured to each of the necks (2,3), remote from the end portions (4). Each mounting member has a first metal body (20) which is fixed to the neck in a selected area. A second metal body (30) is secured to the first metal body (20), and has an aligned surface (31) which is in at least one of three perpendicular directions (x,y,z) in an aligned position with respect to the electric element (5). Each mounting member furthermore has a third metal body (40) having references (12) which is secured to the aligned surface (31), such that its references (12) are in a predetermined aligned position with respect to the electric element (5).

Abstract: An image projection apparatus which comprises an illumination unit, an image display unit, a projection lens and an electro-optical deflection unit arranged between the display unit and the projection lens and being switchable between a first mode and a second mode and comprising a polarization switch and a birefringent element, whereby the light rays from the display unit passing through the deflection unit if the deflection unit is in the first mode are shifted relative to said light rays passing through the deflection unit if this unit is in the second mode. The birefringent element comprises at least one birefringent oriented polymer layer.

Abstract: The electric discharge lamp has a discharge vessel (2), which is mounted in an outer bulb (1). A glass sleeve (10) is surrounding the discharge vessel. A coiled wire (11) is used as an envelope (11) to a glass sleeve. The wire is in an electrically floating manner fixed around the sleeve (10), e.g. by clamping fit. The construction of the lamp is simple an effective to protect the outer bulb (1) from being damaged by an explosion of the lamp vessel (2) and to prevent sodium, if present, to disappear from the discharge vessel as a result of photoemission.

Abstract: An electric reflector lamp is disclosed having a reflecting surface and a neck. A light source having a glass lamp vessel with a pinch seal is accommodated in the reflector body, the pinch seal being located in the neck. A mounting plate is present on the pinch seal. The plate is the bottom of a bush which extends axially along the lamp vessel towards the reflecting surface and which has a transversely extending rim which closes the neck.

Abstract: A lighting unit is disclosed having an electrodeless low pressure discharge lamp which is provided with a discharge vessel closed in a gastight manner and comprising an ionizable filling. The discharge vessel has a recessed portion and an enveloping portion. The recessed portion and the enveloping portion each have a fastening to a metal collar, a coil being arranged in the recessed portion for generating a high-frequency magnetic field for maintaining an electric discharge in the discharge vessel. The enveloping portion is provided at an inner surface with a light-transmitting, electrically conductive layer. The conductive layer is electrically connected to a lead-through member of which the metal collar forms part in that the conductive layer covers a region of the lead-through member which adjoins the inner surface of the enveloping portion and which is at a distance from at least one of the fastenings between the discharge vessel and the collar.

Abstract: A low-pressure mercury vapor discharge lamp according to the invention is provided with a discharge vessel (10) which encloses a discharge space (11) containing mercury and a rare gas in a gaslight manner. The discharge vessel (10) has a light-transmitting tubular portion (12) and a first and a second end portion (13A, 13B). Current supply conductors (20A, 20A'; 20B, 20B') issue through each end portion (13A, 13B) to respective electrodes (21A, 21B) arranged in the discharge space (11). The lamp is further provided with a main amalgam (30) for stabilizing the mercury vapour pressure in the discharge space (11) during normal operation, and with an auxiliary amalgam (31A, 31B) for quickly releasing mercury into the discharge space (11) after switching-on of the lamp. In an equilibrium state at room temperature (25.degree. C.), the mass (m.sub.Hg in mg) of the quantity of mercury absorbed in auxiliary amalgam (31A, 31B) is at most 20 times the mercury vapour pressure (P.sub.

Abstract: Display device comprising a display screen provided with phosphors, and coated with a spectrally selective, light-absorbing coating comprising silicon oxide and at least two dyes. The spectral transmissions for blue, green and red phosphor light are chosen to be such that the electron currents towards the blue, green and red phosphors for obtaining white D (6,500K) are substantially equal.

Abstract: The electric mains voltage lamp has a lamp cap with a cylindrical portion abutting a glass envelope. A resilient cover member circumferentially clamps around and covers the cylindrical portion of the lamp cap and has a circumferential, outwardly extending, flexible collar. The cover member may also cover a cylindrical portion of the envelope which is adjacent the lamp cap. If the envelope is tubular in shape, the cover member may be a sleeve closed at an end thereof which is remote from the lamp cap, so as to cover the whole of the envelope. If the lamp has a bulbous envelope, the lamp may have a resilient domeshaped member covering a portion of the envelope opposite the lamp cap and having an overlap with the cover member. The lamp is able to provide a gastight connection to a lampholder.