Siimpel Corp., an Arcadia, Calif., maker of imaging technology for cellphone cameras, has raised $21.5 million in a fourth round of funding.

SunAmerica Ventures led the round. Other investors include Motorola, Qualcomm and Micron Technology and existing backers Draper Fisher Jurvetson, Scale Venture Partners, Global Catalyst Partners, Portage Venture Partners and Zone Venture Partners.

The company improves imaging for camera technology in cellphones, using MEMS (micro-electro-mechanical systems), optics, electro-optical design, image sensors, packaging and camera electronics.