Patent ID: 8861078

Claim:
A light source adjusting device for a projection system, the projection system further comprising a light source module which is capable of providing a first beam with a first wavelength, the light source adjusting device comprising: a first angle selecting layer for receiving the first beam and allowing a first portion of the first beam to pass therethrough to form a second beam having the first wavelength, in which the first portion is a portion of the first beam that is less than an incident angle; a wavelength converting layer for receiving the second beam transmitted from the first angle selecting layer and converting the second beam having the first wavelength into a third beam having a second wavelength; and a second angle selecting layer for receiving the third beam and allowing a third portion of the third beam to pass therethrough to form a fourth beam having the second wavelength, in which the third portion is a portion of the third beam that is less than an emergence angle; and the light source module comprises: a light source for providing a light beam; a beam splitting unit, wherein the light beam passes through the beam splitting unit to form the first beam with the first wavelength; and a beam collecting unit for collecting the first beam to the first angle selecting layer; wherein the second wavelength is larger than the first wavelength, and the emergence angle is less than the incident angle; the first angle selecting layer is disposed on a first surface of the wavelength converting layer, and the second angle selecting layer is disposed on a second surface of the wavelength converting layer opposite to the first surface; and wherein a fourth portion of the third beam larger than or equal to the emergence angle is reflected by the second angle selecting layer, the fourth portion passes through the wavelength converting layer and then scatters from the first angle selecting layer at a scattering angle, and the scattering angle is substantially less than or equal to the incident angle; the fourth portion is then transferred from the beam collecting unit to the beam splitting unit, and the beam splitting unit reflects the fourth portion to the beam collecting unit so that the beam collecting unit collects the fourth portion to the first angle selecting layer.