| 摘要 |
1,258,408. Electron beam apparatus. MINNESOTA MINING & MFG. CO. 17 Dec., 1968 [18 Dec., 1967], No. 60043/68. Heading H1D. Recording apparatus comprises a film chamber 12 including means for moving a film 14 past an aperture 46 in a member 70 which separates the film chamber from an electron beam chamber 10. The member 70 is provided with a pair of parallel rails, of which one 76 is shown in Fig. 1, against which the film is pressed by a pressure shoe 84 which is provided with a recess 88 opposite the aperture 46. Slots 80 and 82 extend between the rails on each side of the aperture 46 and communicate with extensions of the recess 88 through sprocket holes in the film. The film chamber 12 is reduced in pressure to 15-20 mm. via valve 36 by a fore pump 32 which also (through conduit 49) maintains the slots 80 and 82 at a pressure of 1 mm. and is connected through valve 40 to a diffusion pump 38 adapted to maintain a pressure of 10<SP>-5</SP>-10<SP>-7</SP> mm. at the electron gun 50 and a pressure of 10<SP>-3</SP>-10<SP>-4</SP> mm. at the aperture end of the tube. A flap valve 48 is provided to seal the tube 10 during loading and unloading operations. The film chamber includes a sprocket film drive capstan 20 and a claw 90 driven by cam means (not shown) for incrementally advancing the film through the film gate 22. The electron gun is surrounded by a focusing coil 66 and a scanning coil 68. The apparatus may be used to record 30 frames/sec. television images on film at the rate of 24 film frames/sec. In Fig. 1 the surface of the member 70 contacted by the film is flat; in a modification (Fig. 4, not shown) it is curved convexly. |
