Patent ID: 6771427
Filing Date: 2004-08-03
Classification: G02B,G03B

Abstract:
An image optical system in which a plurality of light beams emerge from an image-forming device on a first conjugate plane having a divergence angle of 10Â° or greater, the beam being obliquely incident upon a second conjugate plane to form on the second conjugate plane an enlarged image substantially similar to an image formed by the image-forming device, said image optical system comprising:a first optical system and a second optical system each having an optical axis, the first optical system converging the plurality of light beams emerging from the image-forming device on both of a first light beam cross section arranged parallel to principal rays and a second light beam cross section intersecting the first light beam cross section, the second optical system converging light beams passing through the first optical system on the second conjugate plane, the image optical system, satisfying the following relationships: (i) S1&lE;L11&lE;S1+S2(ii) S1&lE;L21&lE;S1+S2(iii) L11/L1n<0.25; and (iv) 021/L2n <1.5 wherein S1 is a distance from a point of emergence from the first optical system to a point of incidence of the second optical system along the optical axis of the first optical system; S2 is a distance from a point of emergence from the second optical system to the second conjugate plane along the optical axis of the second optical system; wherein a maximum and a minimum of a distance between a point of convergence in the first and second light beam cross sections of a light beam emerging from the first optical system at a point nearest to the optical axis of the first optical system and the point of emergence from the first optical system are L11 and L21, respectively; and wherein a maximum and a minimum of the distance between the point of convergence in the first and second light beam cross sections of a light beam emerging from the first optical system at a point remotest from the optical axis of the first optical system and the point of emergence from the first optical system are L1n and L2n, respectively.