Light source system and projection device

A projection device, comprising:

• a light source system,
• wherein the light source system comprises:
• a light source;
• a first lens group;
• a wavelength conversion element comprising a wavelength conversion region and a reflection region;
• a light guiding assembly comprising a light guiding element;
• and
• a light homogenizing element,
• wherein a first-color light generated by the light source is incident on the first lens group through the light guiding element, or the first-color light generated by the light source is directly incident on the first lens group;
• when the first-color light is incident on the wavelength conversion region after being focused by the first lens group, the wavelength conversion region is excited by the first-color light to emit a second-color light, and the second-color light is incident on the first lens group and is incident on the light guiding assembly through the first lens group;
• when the first-color light is incident on the reflection region after being focused by the first lens group, the first-color light is reflected by the reflection region, and is incident on the light guiding assembly through the first lens group;
• the first-color light or the second-color light that is incident on the light guiding assembly is incident on the light homogenizing element through the light guiding assembly, and exits after being homogenized by the light homogenizing element;
• and
• a light spot of the second-color light emitted from the first lens group is elliptical, and a first distance between an optical axis of the first-color light emitted from the light source to the first lens group and an optical axis of the first lens group is greater than 0.