Color wheel module and projection device

A projection device, comprising an illumination system, a light valve and a projection lens, wherein:

• the illumination system is configured to provide an illumination beam, and the illumination system comprises a light source module and a color wheel module, wherein:
• the light source module is configured to provide an excitation beam;
• and
• the color wheel module is disposed on a transmission path of the excitation beam, and the color wheel module comprises a driving element, a first rotating member, a second rotating member and an annular optical member, wherein:
• the driving element comprises a rotating shaft, and the driving element is configured to drive the first rotating member and the second rotating member to rotate;
• the first rotating member is disposed on the rotating shaft, and the first rotating member comprises a first reflective area, a second reflective area and a wavelength conversion material, wherein:
• the second reflective area is connected to an outer edge of the first reflective area, and the first reflective area is inclined to the second reflective area;
• and
• the wavelength conversion material is disposed on the first reflective area, and is configured to convert the excitation beam into a conversion beam;
• and
• the second rotating member is disposed on the rotating shaft and connected to the first reflective area of the first rotating member;
• and
• the annular optical member is disposed between the first rotating member and the second rotating member to form an optical cavity with the first rotating member and the second rotating member, wherein one of the second rotating member and the annular optical member comprises a dichroic layer, and the other comprises a filter area and a transmission area;
• the light valve is disposed on a transmission path of the illumination beam, and is configured to convert the illumination beam into an image beam, wherein the illumination beam comprises at least one of the excitation beam and the conversion beam;
• and
• the projection lens is disposed on a transmission path of the image beam, and is configured to project the image beam out of the projection device.