Patent GB-385624-A (GB)
Title: Improvements in or relating to the optical representation of objects with stereoscopic effect
IPC: G03B35/00
Filed: 1931-04-01
Abstract: 385,624. Stereoscopic kinematography. SAVAGE, L. F., 20, Old Compton Street, London. April 1, 1931, No. 9925. [Class 97 (i).] Means for producing optical representations of objects with stereoscopic effect comprises a number of optical systems disposed to produce separate view point images and to project them in superposition upon the common focal plane, the optical systems or components thereof being given two continued movements of reciprocation or oscillation, one of which serves to effect the successive superposition of the images of objects at different distances comprised in the separate view point images while the other effects an adjustment of the objectives or other components of the optical systems for the purposes of accurately focusing the objects simultaneously. As shown in Figs. 1, 3, and 5, the lens tubes a are supported in the sleeves b carried by the spindles bl rotatable within the pedestals b<2> and carrying at their ends below the baseplate c the levers b<3>, which carry studs b4 engaging the surface d<2> on a slidable bar d. A tension spring b<5> is connected between the levers b<3>, and springs d<6> bear on the studs b<4>. The bar d is reciprocated by means of a spindle e driven through the bevel gear e<2> from the operating gear of the camera. A rotatable sleeve g has a head g<1> in which is a transverse slide block g<2> carrying a crank pin g<3> rotatable in a slide block d<3> in a slot in the perpendicular arm d<4> of the bar d. The block g<2> is adjustable for the adjustment of the eccentricity of the crank pin g<3> by engagement with an eccentric pin h<1> provided at the end of a spindle h rotatable within the sleeve g and engaging a pin c4 adjustable in a bridge member c<5>. The sleeve g has an annular helical gear g4 engaging a helical gear e<3> on the spindle e, while the spindle h carries a helical gear h<2> of the opposite hand engaging a gear i<1> loose on a spindle i provided with a loose helical gear i<2> of opposite hand and secured to the gear i<1>, the gear i<2> engaging a gear e4 integral with the gear e<3> or fixed on the driven spindle e. To vary the eccentricity of the crank pin g<3> of the slide block g<2> the spindle i is axially movable, the extremity being provided with a threaded portion received into a fixed nut c<2>. The objective lenses are reciprocated for focusing by providing the bar d with an arm d<5> carrying at its upper end a crosshead d<6> to which are pivoted two arms j pivoted at the outer ends by pins j<1> secured to the sleeves j<2> embracing the lens tubes a and carrying pins a<2> extending through slots in the lens tubes to engage the lens mounts. To permit of initial focusing the crosshead d<6> has a slot in respect of each arm j engaging a pin j<3> fitting into a sleeve in the slot retained in adjusted position by screws d<7>. Axial movement of the arms relative to the lens tubes a is permitted by the pins b<7> on the bosses b<6> on the sleeves b fitted in slots in the arms j. For focussing the system according to the average distance of a particular view, the sleeve f is mounted on a slide k provided with a nut k<1> engaging a threaded spindle k<2> provided with a gear k4 engaged by a gear k<5> on a spindle k<6> provided with a knob k<7> having a pointer k<8> co-operating with a scale k<9>. By engagement of the crank pin g<3>'with the arm d<4> of the bar d movement of the sleeve f is communicated to the lenses through the arm d<5>, and the arms j. Brackets m carry two shutter-rotating spindles m<1> one of which is rotated from the spindle e through the gear m<2> and transmits rotation to the other spindle by the bevel gearing m<4> and the spindle m<3>. Indicating mechanism for the extent of the movement of the bar d comprises a pivoted lever n<1> having a stud n<3> engaging under the action of a spring n<4> one end of the block g<2> sliding in the slot of the arm d4. The lever n<1> has a toothed segment driving a pinion upon a spindle n<5> carrying a pointer-n<6> co-operating with a dial n. In a modification, tubular casings containing the optical components are so mounted that they may be given a slight angular movement about axes transverse to the axis of binocular vision while at the same time the objective lenses are axially moved to adjust the focus. In a further modification especially applicable for use with optical systems serving to project the separated view point images upon a focal plane disposed along the centre line of binocular vision the objectives are reciprocated in a direction transverse to the centre line of the binocular field and also axially for focus. Specifications 346,679 and 352,773 are referred to.