GB613093A - Improvements in or relating to cinematograph projection apparatus - Google Patents

Abstract

613,093. Kinematograph projectors. PHILIPS LAMPS, Ltd. Aug. 1, 1946, No. 22922. Convention date, Dec. 2, 1939. [Class 97 (i)] An arc lamp and a liquid-cooled high-pressure mercury vapour lamp are provided for alternative use in a projector, the mercury vapour lamp being movable-into and out of operative position within a barrel shutter ; the shutter blades may comprise interchangeable members, some of which are transparent and correct for the colour of the mercury vapour lamp. As shown in Fig. 3, the beam reflected by a mirror 45 from an arc lamp B has its apex in the gate aperture 43 and is passed by the shutter 42. A holder 40 for the mercury vapour lamp is carried by an arm 50, which may be swung about a pivot 51 into and out of the shutter. Cooling liquid and electric current may be supplied to the holder 40 through the arm 50 and may be automatically cut off when the holder is in position III, Fig. 5, and operative when the holder is in position I or II; position II allows the lamp to be conditioned before being placed in position I. A liquid-cooled lens 41 may be provided in front of the holder 40 and a lens 44 may be carried by a branch 49 of arm 50 to be positioned outside the shutter when in use, the lenses serving to focus the beam on the projection lens D. The shutter, Fig. 6, may be interchangeable and may have interchangeable blades 47 as of aluminium or coloured transparent material, separately removable through passages 46.