Patent GB-717088-A (GB)
Title: Improvements in photomicrographic apparatus
Inventor: EVANS WILLIAM DAVID
IPC: G02B21/36
Filed: 1952-07-14
Abstract: 717,088. Photo-micrography. COOKE, TROUGHTON & SIMMS, Ltd. July 14, 1953 [July 14, 1952], No. 17745/52. Classes 97(1) and 98(1). A photo-micrographic attachment for use with a microscope comprises a frame adapted to be mounted on the eye-end of a-microscope, a holder movable relatively to the frame from a focusing position to an exposure position and vice versa, the holder having an aperture through which observations can be made for focusing when the holder is in focusing position, and having means for securing a photographic film or plate to the holder so that the film or plate is exposed when the holder is slid to the exposure position, and there being means that screens the film or plate except when the holder is in the exposure position so that the holder and screening means are together removable from the frame so that the exposed film or plate is screened pending its removal in a dark room. As shown, a rectangular. frame 1 has inwardly facing channelled sides 2 in which a film holder 4 is slidable. The holder 4 has a circular aperture 6 and a rectangular aperture 14, overlaid with a glass sheet 16, which is ground or marked with cross-lines at aperture 6. In the focusing position, aperture 6 is aligned with the microscope axis and the ground glass or cross-lines are viewed by an eyepiece 10 mounted on holder 4, to enable the microscope to be focused. A photographic film or plate 15 is held against the glass sheet 16 in register with aperture 14 by a plate 38. which is removably secured to holder 4 by a turnbuckle having a knob 40 engaging cleats (not shown) on the holder 4. Alternatively a ground glass screen is provided under aperture 6 only, and the film or plate is clamped against aperture 14, without glass. A screen 18 slides under aperture 14 to prevent light from reaching the film or plate. Springs 25 extending in bores in holder 4 are connected to the end 31 of holder 4 and to a bar 20 mounted at the edge of screen 18. To make an exposure, holder 4 is moved against springs 25 until a spring-pressed detent 35 on frame 1 engages a notch 34 in holder 4 so that the holder is retained in exposure position with aperture 14 aligned with the microscope axis. After exposure, a button 37 is retracted to withdraw detent 35 from notch 34 to allow holder 4 to return under action of springs 25. The film or plate is now screened by screen 18, and the holder can be removed to a dark room. The frame 1 can be attached to the microscope in alternative ways. On the left hand side of Fig. 1, a plate 46 carries a socket 47 clamped to the tube 12 of the microscope. The microscope eyepiece is removed and a sleeve 52 fitting inside the tube carries a lens 51 by which the image is formed, and which may also increase the magnification. On the right-hand side of Fig. 1, the eyepiece 53 of the microscope remains in place, and a tube 55 is clamped thereto. A shutter 56 is screwed on to tube 55 and also on to a tube 12 connected by an adaptor to frame 1. A lens 61 focuses the parallel light emerging from the microscope eyepiece on to the focusing screen or the film or plate. According to the Provisional Specification, roll film may be used.