| 摘要 |
A phase difference compensating element that can effectively compensate polarization disturbance, and a projection-type image projecting device are provided. The phase difference compensating element includes: a birefringent layer (33) formed with a film stack of obliquely-deposited films, each of the obliquely-deposited films having a thickness equal to or smaller than the used wavelength; and an Rd-AR film (32) that is formed with a film stack of two or more kinds of dielectric films having different refractive indexes, and provides an arbitrary phase difference to a phase difference in obliquely-incident transmitted light in the birefringent layer (33). The phase difference Rd to be provided by the Rd-AR film (32) satisfies 1 < Rd(»)/Rd(»') < 1.5 (» < »'), at an arbitrary wavelength » in the used wavelength band and within an incident light angle range of 0 to 25 degrees. |
