GB359810A - Improvements in and relating to means for graduating record surfaces photographically - Google Patents

Abstract

359,810. Recording-apparatus. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Jan. 2, 1931, No. 244. Convention date, Jan. 3, 1930. [Class 106 (iv).] Graduation of record surface.-In a photographic recording device particularly for use with an oscillograph the record strip has the time ordinates marked thereon by means of a rotatable mirror in associ ation with a known optical arrangement, the mirror being mounted on an axis transverse to the direction of the strip movement. As shown in Figs. 1 and 2, a source of light 1, a lens 2, and a screen 7 with a rectangular aperture throws a pyramid of rays on to a mirror 3 from which the rays are reflected and fall upon a cylindrical lens 4 to produce a line upon record drum 5. The mirror 3 is mounted on the shaft of a constant high speed motor 6. The length 9, 10 of the ordinate depends on the angle alpha due to the length 12 of the screen aperture, the breadth of the line depends upon the angle # due to the width 13 of the screen aperture. The breadth of the line can be varied by utilizing mirrors of different width. To produce a series of time ordinates with every fifth or tenth line of different width the shaft of the motor has a series of mirrors arranged around it one of which is wider than the others. The speed of the motor is reduced in accordance with the number of mirrors employed. In another arrangement for producing every fifth line thicker a screen 15, Fig. 2, on an axis 17 is provided so as to intercept a part of the beam of light during the time that the thinner ordinates are produced.