US 11,899,170 B2
Optical lens and projection apparatus
Yu-Chen Lin, Hsinchu Science Park (TW); and Chun-Tung Wu, Hsinchu Science Park (TW)
Assigned to YOUNG OPTICS INC., Hsinchuscience Park (TW)
Filed by Young Optics Inc., Hsinchu Science Park (TW)
Filed on Jul. 1, 2020, as Appl. No. 16/918,265.
Claims priority of application No. 108123040 (TW), filed on Jul. 1, 2019.
Prior Publication US 2021/0003823 A1, Jan. 7, 2021
Int. Cl. G02B 13/00 (2006.01); G02B 9/34 (2006.01); G02B 1/04 (2006.01); G03B 21/20 (2006.01); G02B 27/42 (2006.01)
CPC G02B 13/004 (2013.01) [G02B 1/041 (2013.01); G02B 9/34 (2013.01); G02B 13/0055 (2013.01); G02B 27/4205 (2013.01); G03B 21/2006 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A projection lens, comprising:
a first lens with a positive refractive power, a second lens having a diffractive optical surface and a negative refractive power, and a third lens with a positive refractive power arranged in order from a magnified side to a minified side, a total number of lenses with refractive powers in the projection lens being smaller than six, and the first lens, the second lens and the third lens of the projection lens being aspheric lenses and made of plastic.