摘要:
Disclosed are optical couplers (10) and optical coupling systems for coupling a source of non-coherent light to a light distribution harness, wherein the couplers are polygonal in cross section to increase light mixing. The couplers have inlet (12) and outlet (14) arms and an intermediate bend region (16A) configured to achieve compactness and minimal light loss through the bend region. In one embodiment, the bend region is an integral part of the coupler, with the inlet arm having a different cross-sectional dimension (12A) from the outlet arm (14A) in such manner that substantially all light (30) directed from the inlet portion (12) to the bend portion (16A) reaches (31,32) the outlet arm portion (14), and light rays parallel to the inlet axis are reflected in the bend portion to be directed substantially parallel to the outlet axis. In a second embodiment, the bend region comprises a prism having a pair of parallel spaced surfaces, and inlet, outlet, and third surfaces that are non-parallel to the spaced surfaces. The inlet arm projects from the inlet surface, and the outlet arm projects from the outlet surface. One of the inlet and outlet surfaces forms a first interface with a first material having an index of refraction different from that of the prism, so that light rays within the prism totally internally reflect from the first interface.
摘要:
A high pressure discharge lamp (10) with a thermally improved anode (18), as well as a method of making such a lamp, are disclosed. The lamp includes a refractory arc tube (12) with a hermetically sealed arc chamber (14), a fill in the arc chamber for facilitating light generation, and an anode (18) and a cathode (16) extending into the hermetically sealed arc chamber (14) and being spaced apart from each other. The anode (18) comprises a shank of refractory metal (20), a cylindrically shaped refractory metal sleeve (318b) on a portion of the shank (20), and an end proximally facing the cathode (16). The anode (18) end comprises a substantially solid mass of refractory metal, and is integrally joined to both the shank (20) and the metal sleeve (318b) to facilitate heat flow from the anode (18) end to the shank (20) and sleeve (312b). The anode (18) end preferably is generally shaped as a hemisphere facing the cathode (16). The fill may comprise mercury, metal halide, and xenon at a relatively high fill pressure. The anode (18) may be formed by, first, providing a refractory metal shank (20), and placing a refractory metal sleeve (318b), e.g., one or more layers of a helically wound refractory metal wire, along a portion of the shank (20), to form a sleeve-shank combination. A portion of the sleeve-shank combination, facing downwards, is then heated sufficiently to cause metal from the sleeve-shank combination to ball up and form an anode end that integrally joins both the shank (20) and the metal sleeve (318b). The heating is preferably sufficient to cause the anode (18) end to ball up into a generally hemispherical shape.
摘要:
Anode and cathode means are provided for a metal halide lamp which cooperate in providing more rapid light output during lamp start-up. A xenon-metal halide lamp employing the improved discharge electrode means is disclosed along with an automotive headlamp having this lamp for its light source.
摘要:
Miniature high pressure arc lamps containing a substantial pressure of xenon, in addition to metal halide and mercury, can provide instant light at turn-on and are suitable for automotive headlamps. The xenon aggravates convection which causes arc-bowing and overheating of the envelope above the arc. By operating the lamps on unidirectional current upon which a frequency-modulated high frequency ripple has been imposed, acoustic resonance is used to straighten out the arc. The use of unidirectional current permits a reduction in cost and size of the ballast control circuits operated from auto storage battery. Frequency modulation of the ripple broadens the band allowing acoustic straightening of the arc. Additional control of the arc plus reduction of cataphoresis may be achieved through a horizontal magnetic field at the arc, transverse to current flow.
摘要:
A significant reduction in thermal energy loss along the legs or ends of the arctubes in a CMH lamp is achieved in the present invention. The diameter of a mandrel (36, 40) is significantly reduced for CMH lamps. Either a single overwind (32) or multiple overwind layers (42) are used. Since the thermal conductivity of the mandrel greatly exceeds that of the overwind, the axial thermal conductivity will scale like the cross sectional area of the mandrel alone.
摘要:
Heat sink means (40) are provided for a metal halide lamp to enable more light output during lamp start-up. A xenon-metal halide lamp employing the heat sink means (40) is disclosed along an with automotive headlamp having this lamp for its light source.
摘要:
An arc discharge headlamp system employs a single continuously operating arc discharge source to provide both high and low beam patterns. The continuously operating arc discharge increases lamp life and eliminates the problem in arc light source headlamp systems of momentary dimming when switching to high beam operation due to mercury condensing within source. The headlamp (10) has an arc light source (14) mounted horizontally within a reflector (12). Light from the arc light source is reflected by the reflector through a lens (15) to form a low beam pattern. A mirror (22) within the reflector is positioned to form a virtual image (24) of the light source, which is directed towards a second lens (26) concentric with the first lens to form a high beam pattern when combined with the low beam pattern. Switching between the high beam and low beam patterns is accomplished in a variety of ways. In the preferred embodiment, the second lens incorporates an electrically responsive light valve (34) which either passes or blocks the virtual image of the arc light source. Alternatively, the mirror may be moved between a position that directs the virtual image through the lens to a position where the virtual image is not directed through the lens. Rather than moving the mirror, it may be blocked with a mask during low beam operation.
摘要:
A method and a ballast circuit are disclosed for operating e.g. a xenon-metal halide lamp particularly suited for automotive applications. The method applies to the lamp a direct current (DC) having selectable amount of ripple imposed thereon. The ripple provides for acoustically straightening the arc between the electrodes of the xenon-metal halide lamp. The DC acoustic operation has the capability of utilizing cataphoresis effect so as to provide a less distracting forward beam illumination for a vehicle.