| 摘要 |
<p>PURPOSE: To uniform illumination and improve light transmitting efficiency, by constituting the unit lens of a fly's-eye lens of many annular pattern parts having the same center and different diameters and etching parts arranged alternately with the pattern parts, and transmitting incident light. CONSTITUTION: A fly's-eye lens is constituted by densely arranging many small unit lenses. The unit lens 5 is provided with many annular pattern parts 6 having the same center and different diameters, and etching parts 7 arranged alternately with the pattern parts 7. The etching parts 7 are formed to have transmission phase difference of 180 deg. to the pattern parts 6. When a wavelength isλand a refractive index is n, the depth to be etched of the etching part 7 is desired to beλ/2(n-1), in order to have the phase difference of 180 deg.. Thereby lights having the same phase are transmitted, and the phase of a light different in phase is inverted by 180 deg. when the light passes the unit lenses 5, so that the same effect can be obtained.</p> |
