Patent GB-785843-A (GB)
Title: Reading device for characters represented on a plate in micro-reproduction
IPC: G02B27/02
Filed: 1955-02-25
Abstract: 785,843. Viewing apparatus. KORNER, T., and POHL, W. F. Feb. 25, 1955 [May 21, 1954; Sept. 13, 1954; Jan. 25, 1955], No. 5774/55. Class 97(1) Guiding members are provided on both sides of a plate for a runner carrying a .simple or compound microscope for reading micro-film size print on both sides of the plate. If the plate 1 is circular (Fig. 2), rigid U-shaped members 3 carrying runner 4 are releasably pivoted at its centre and the plate may be rotated by a spring. If the plate 12 is rectangular the guiding members may be rigid U-shaped members 25 (Figs. 7 and 8) or flexible elastically extensible strings 53 (Fig. 17) of rubber or in the form of spiral springs each encircling the plate 12. Strings 53 may pass through holes or eyes in the runner of a simple microscope 54 and may lie in pairs of notches 59 in the opposite edges of the plate or be attached to only one edge of the plate. The notches may alternatively be provided in sliders movable along the opposite edges of the plates. A simple microscope which may be interchangeable is described in connection with most of the embodiments of the invention. In one form however, which may be used with either a circular plate or a rectangular plate and slider, a rigid or springy U-shaped member engages two eyes on a runner having a conical or cylindrical bore in which the tube of an interchangeable compound microscope can be mounted. The connection between the runner and the U-shaped member may be magnetic, one of them being a permanent magnet. Alternatively, an intermediate member, which may or may not be magnetic, may run in a groove in the outer face of the U-shaped members and engage recesses in the corresponding faces of the runner. The runner is alternatively and may additionaly be connected to the U-shaped members by pin and groove engagement or interengaging flanges. Further stabilizing elements may be necessary to prevent the runner from tilting about the axis of the pins and these elements are only operative over the straight leg parts of the U-shaped members. A leaf spring arrangement may be provided to ensure that the appropriate surfaces of the runner contact the locating surfaces of the U-shaped member and may frictionaly retain the runner in position. As shown in Figs. 7 and 8, a U-shaped frame member 17 clamps the plate 12 including the microgram plate 16 and covering sheets 11, and provides a guide track 22 for the slides 23 carrying the U-shaped member 25. The frame member 17 may extend down only one side of the plate 12 and may be secured thereto by screws or rivets or may be in the form of a spring clip and secured by spring pressure. An additional frame member is then provided on the opposite side of the plate. As shown, the edge of the plate remote from the slider is held together by studs 27. A low power lens 30 may be attached to the tube 32 of simple microscope 26 by a spring clip and is used for locating the position of the desired information on the microgram plate 16. Alternatively, the lens 30 may be slidably mounted on the U-shaped member 25. The visual field of the microscope may be illuminated by a condenser lens located on the opposite side of the plate. The condenser lens may be coupled with the microscope so as to move with it over the plate. If the microgram plate is thin it is made of either translucent, non-transparent material or opaque material. A binocular microscope may be used.