Patent GB-1282311-A (GB)
Title: Optical device
Inventor: ROTTER JOHANN
IPC: G02B13/00
Filed: 1969-08-29
Abstract: 1282311 Optical apparatus; photographic reader printers J ROTTER 29 Aug 1969 [4 Sept 1968] 43175/69 Headings G2A and G2J An optical device for projection, reproduction and viewing of planar objects comprises a first image forming optical system positioned closer to an object, a second image forming optical system positioned close to the final image formed by the device, an intermediate image plane between the first and second image forming systems to produce a real intermediate image, said intermediate image plane being stationary in the device, the first image-forming system having a part changeable to change the field diameter of the object as detected by that system at least once by a factor of #2, the distance of the plane of the object from the intermediate image plane and the position of the intermediate image plane relative to the final image plane produced by the second optical system remaining constant. In one embodiment, Fig. 3, an objective 11 is mounted for movement through 180 degrees and has attachments 20, 21 for changing its field diameter. An intermediate image plane is located at 28 and viewed by an axially adjustable eyepiece 12. An illuminating system 17-19 is rotatable about the optic axis and illuminates e. g. a text which is focused by the optical device 11, 12 on, for example, a camera 30 which is moved into the image plane 34. Alternatively a reel of microfilm may be used which is illuminated by source 25. The whole device is mounted in a frame 14, 15 which may be hand held. In another embodiment Fig. 4, an object is illuminated through a variable gate 46 and a record made on film at an image plane 49 the optical parts comprising objective 41 with attachable member 50, prism 44, axially movable eye-piece 42 and prism 47. If desired prism 44 can be moved out of operation and the Fig. 3 apparatus used, but with the eye-piece 42 in place of eye-piece 12. In a further embodiment, Fig. 6 (not shown) a vertically mounted objective (76), having detachable members (78) (79) for altering the field of view, may be focused on two spaced horizontal planes depending on the object size, a series of reflectors (106), (106<SP>1</SP>) directing light from two sources (105) on to these planes. The image is erected via an eye-piece (77) and mirror (97) on a vertical reproducing device (96). If desired objective (76) may be replaced by a horizontally mounted objective (115) for reproducing vertically mounted e.g. card indexes (60) (60<SP>1</SP>). An adjustable mirror system and rotatable mask with variable apertures are used in conjunction with objective (115). Another embodiment shows an objective 130, Fig. 10, which may be replaced by a second objective 131 by interposing a mirror 132 on optic axis of objective 130. Light from the objectives passes through one of two different sized apertures in a rotatable mesh which carries two eye-pieces 138, 139, one associated with each aperture. An image can be directly erected on plane 143 through prism 140; or the prism rotated to rotate light path 180 degrees or the light path rotated through 180 degrees by a prism 141 to reach image plane 143 via mirrors or prisms 147, 150 or 151. Mirrors 147 are located on each side of a 12- sided bevel wheel located centrally of a 12-sided shaft, each shaft half having six mirrors or prisms 150, 151, Fig. 9, helically arranged. Thus rotation of shaft through 30 degrees brings a different prism into line and so twelve adjacent images can be sequentially recorded on plane 143. A variant with five prisms is given in Fig. 12 (not shown). A suitable objective is illustrated in Fig. 13 (not shown) consisting of six components of which 2nd and 3rd and 6th are single lens elements. The fourth and fifth may be rotated together through 180 degrees or through 90 degrees and out of light path. Optical data is given for the lenses.