GB702034A - Improvements relating to binocular telescopes - Google Patents

Abstract

702,034. Telescopes. BARR & STROUD, Ltd. June 15, 1950 [July 1, 1949], No. 17433/49. Class 97(1) A binocular telescope includes a binocular eyepiece and a pair of objective lenses at the objective end and one or both of two separate light beams from the target is or are inclined towards the telescope axis by first optical means to cause said beams to pass through one or more common lenses of the telescope with substantial overlap of the beams thereat, said beams being thereafter rendered parallel by second optical means. As shown in Fig. 3, light from an object is received by prisms 8 of the telescope which are arranged so that the beams emergent therefrom are relatively inclined and pass through separate objectives 9, the axes of which are also inclined to the telescopic axis. The light beams, after passing through collecting lenses 10, diverge so as to overlap at a lens 11 which refracts the rays of each beam so that the beam emerging from the right (or left) hand prism 8 enters the left (or right) hand prism system 13 and the eyepiece 14 associated therewith. The prism systems 13 consist of right angled prisms which reflect the beams into parallelism and step prisms which direct the beams into the eyepieces 14. In other forms (a) the beams emergent from prisms 8 are parallel and, after passing through objectives having their axes parallel to the telescope axis, are so deviated by refracting prisms that the beams overlap at lens 11; (b) one prism 8 and the objective 9 associated therewith is disposed on the telescope axis and the beam emerging from the other prism 8 is alone deviated by a refracting prism so that the two beams overlap at lens 11; this latter beam is also deviated after passing through lens 11 so as to enter one of the eyepiece prisms; (c) the beams emerging from prisms 8 and objectives 9 are parallel and are deviated by prismatic lenses so that they overlap at two axially spaced and parallel lenses 11, prismatic lenses also being provided in the path of each beam emerging from the second lens 11 so that the beams enter the separate eyepieces; the two sets of prismatic lenses may be replaced by refracting prisms and another set of refracting prisms may be provided between the two lenses 11. The prism systems 13 may be combined in one prism arranged so that the beam emerging from the right (or left) hand prism 8 enters the right (or left) hand eyepiece 14 giving orthostereoscopic vision.