| 摘要 |
451,132. Television. SCOPHONY, Ltd., and WALTON, G. W., Thornwood Lodge, Campden Hill, London. April 25, 1935, No. 12490. [Class 40 (iii)] Relates to a television scanning system in which an image of a light source is caused to traverse a surface to be scanned by means of two scanning members, one of which moves at a high and the other at a low speed. The invention consists in the provision of a first optical system which forms two cylindrical images of the light source in separate planes, one image being on the optical surface of the high speed scanning member and having definition in a direction at right angles to the direction of movement of this member, and the second being in some other plane, e.g. on the surface to be scanned or on the surface of the low speed scanning member, and having definition in a direction at right angles to the direction of definition of the first image, and a second optical system which forms or assists in forming on the surface to be scanned a two-dimensional image of the light source from the two cylindrical images. As shown, the lens 4 forms a cylindrical image of the slit 1 on the reflecting surface 10 of the high speed mirror drum 6, the diverging beam from which is focused by the lens 5 so that a cylindrical image of the surface 10 is formed after reflection of the beam from the surface 11 of the low speed mirror drum 7 on the surface 2. The lens 3 is adapted to focus a cylindrical image of the slit on the surface 2. According to a modification, the lens 3 is arranged to focus a cylindrical image of the slit on the surface 11 of the drum 7 and a cylindrical lens 14 is provided which forms a cylindrical image of this surface on the surface 2. The invention may be applied to a scanning system employing oscillating mirrors instead of mirror drums. |
