US 12,271,104 B2
Light-source device, image projection apparatus, and display device
Yohei Takano, Kanagawa (JP); Makoto Hirakawa, Tokyo (JP); Kazuhiro Fujita, Tokyo (JP); and Takashi Sasaki, Kanagawa (JP)
Assigned to RICOH COMPANY, LTD., Tokyo (JP)
Filed by Yohei Takano, Kanagawa (JP); Makoto Hirakawa, Tokyo (JP); Kazuhiro Fujita, Tokyo (JP); and Takashi Sasaki, Kanagawa (JP)
Filed on Sep. 16, 2022, as Appl. No. 17/946,058.
Claims priority of application No. 2021-162136 (JP), filed on Sep. 30, 2021; application No. 2021-162354 (JP), filed on Sep. 30, 2021; and application No. 2022-114201 (JP), filed on Jul. 15, 2022.
Prior Publication US 2023/0110183 A1, Apr. 13, 2023
Int. Cl. G03B 21/20 (2006.01); G02B 26/00 (2006.01)
CPC G03B 21/204 (2013.01) [G02B 26/008 (2013.01); G03B 21/2066 (2013.01); G03B 21/208 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A light-source device, comprising:
a light source to emit light;
an optical element having a lens array on one side or both sides of which a plurality of lenses are arrayed with distance from each other, the distance between a pair of vertices of an adjacent pair of the plurality of lenses of the optical element being equal to or less than one-quarter of width of light flux of the light incident on the optical element;
a wavelength conversion element to convert a wavelength of the light emitted from the light source and passed through the optical element; and
a second optical system disposed between the optical element and the wavelength conversion element, the second optical system including a pair of lenses,
wherein the width of the light flux is equal to or shorter than one-third of an external diameter of one of the pair of lenses closer to the light source than another one of the pair of lenses of the second optical system.