US 11,720,009 B2
Illumination system and projection device
Hung-Wei Liu, Hsin-Chu (TW)
Assigned to Coretronic Corporation, Hsin-Chu (TW)
Filed by Coretronic Corporation, Hsin-Chu (TW)
Filed on Sep. 9, 2021, as Appl. No. 17/471,154.
Claims priority of application No. 202022350134.X (CN), filed on Oct. 21, 2020.
Prior Publication US 2022/0121094 A1, Apr. 21, 2022
Int. Cl. G03B 21/20 (2006.01); G02B 27/14 (2006.01); G02B 27/28 (2006.01)
CPC G03B 21/204 (2013.01) [G02B 27/141 (2013.01); G02B 27/283 (2013.01); G03B 21/208 (2013.01); G03B 21/2013 (2013.01)] 38 Claims
OG exemplary drawing
 
1. An illumination system configured to provide an illumination beam, wherein the illumination system comprises: a first blue light source, a second blue light source, an optical path switching element, a first light splitting element, a phosphor wheel, and a light homogenizing element, wherein
the first blue light source is configured to emit first blue light;
the second blue light source is configured to emit second blue light, and a peak wavelength of the first blue light is greater than a peak wavelength of the second blue light;
the optical path switching element and the first light splitting element are disposed on a transmission path of the first blue light, the first light splitting element is disposed between the first blue light source and the light homogenizing element, and the optical path switching element is disposed between the first blue light source and the first light splitting element, and the optical path switching element is an optical wheel and has a penetration region and a reflection region;
the phosphor wheel is disposed on a transmission path of the second blue light, wherein
at a timing for blue light, the penetration region of the optical path switching element cuts into the transmission path of the first blue light, the first blue light source is turned on, the second blue light source is not turned on, and the first blue light emitted from the first blue light source sequentially penetrates the penetration region, the first light splitting element and the light homogenizing element, so that the illumination system outputs blue light of the illumination beam;
at a timing for green light, the reflection region of the optical path switching element cuts into the transmission path of the first blue light, the first blue light source and the second blue light source are turned on simultaneously, the first blue light emitted from the first blue light source is transmitted to the first light splitting element and the phosphor wheel after being reflected by the reflection region, and the first blue light is converted into first green light via the phosphor wheel, the first green light is then transmitted to the first light splitting element and penetrates the light homogenizing element, and simultaneously the second blue light emitted from the second blue light source is sequentially transmitted to the first light splitting element and the phosphor wheel, the second blue light is converted into second green light via the phosphor wheel, and the second green light is then transmitted to the first light splitting element and penetrates the light homogenizing element, so that the illumination system outputs green light of the illumination beam, wherein the green light comprises the first green light and the second green light.