| 摘要 |
PURPOSE:To attain the complete reproduction of information by providing a small curvature radius and large power to the lenses of both 1st and 2nd cylindrical lens systems to shorten the optical path of the cylindrical lens system and also to satisfy the Petzval conditions for the cylindrical lens system. CONSTITUTION:The laser beam passed through the 1st cylindrical lens 2 is spread with a large angle, i.e., a large beam opening angle to the center beam serving as the center of the luminous flux of the laser beam before passing through the lens 2. Therefore the length L of the optical path is reduced between both lenses 2 and 3. Here a cylindrical lens system 1 consisting of lenses 2 and 3 is formed to satisfy the Petzval conditions. That is, 1/n1f1+1/n2f2+-1/nkfk=0 is satisfied, where ni, fi and k mean the refractive index of each cylindrical lens, the focal distance and the number of cylindrical lenses forming a cylindrical lens system respectively. As a result, the image surface curvature aberration can be avoided. |
