| 摘要 |
1,194,813. Photo-copying apparatus; optical projection systems. RICOH K. K. Feb. 14, 1969 [Feb. 17, 1968], No.8057/69. Headings G2A and G2J. An optical arrangement comprises a lens 2; first and second inclined mirrors 3, 4 lying on opposite sides of the lens' optical axis; a third mirror 1 also on the optical axis and arranged so that light from a tubular source (6), Fig.1 (not shown) reflected by the first mirror 3 through the lens 2 is returned to the lens and directed towards the second mirror 4; and a shield 10 lying on the optical axis as shown, the shield being so profiled that the light impinging on the mirror 4 is reflected on to a planar surface to provide substantially even illumination thereof. In use, the lens, mirrors, and light are supported by a housing (7) slidably mounted for movement between an original (5) and a photo-copying sheet (8) for a scanning exposure. The shape of the leading edge 10a of the shield is arranged to correct for the characteristics of the light source (6) and the lens 2 so as to give an even distribution of light intensity over the sheet (8). The leading edge 10a, besides being curved, is reduced in width and a portion 10b of the shield is recessed. |
