| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical system by which chromatic aberration of magnification is corrected successfully and high image quality is provided, over the whole display screen. <P>SOLUTION: The optical system includes at least one lens group having negative refractive power on the object side relative to an opening SP which determines a maximum luminous flux diameter on an axis. The lens group having negative refractive power includes a lens group having at least one positive lens and negative lens with negative refractive power. After making the ratio of the positive lens to the negative lens appropriate, the lens group with negative refractive power includes a plurality of negative lenses having an appropriate Abbe number and a partial dispersion ratio and a positive lens having an appropriate Abbe number, and a negative lens having the highest dispersion out of the negative lenses is arranged at an appropriate position. <P>COPYRIGHT: (C)2013,JPO&INPIT |
