In this paper, we proposed a miniature auto-focus image system without moving components. We had previously
presented a 2-Mega-Pixel auto-focus module by combining reflective optics, refractive optics and MEMS
deformable mirror. This configuration can be further improved. We expanded 2-Mega-Pixel image plane to 8-Mega-Pixel image plane and corrected the aberration by adding one more lens as a stop. For the concern of the
cost, we distributed the optical power of the adding lens to the fixed reflecting mirror and the deformable mirror,
and we designed them as freeform surfaces to compensate aberrations. Finally, an 8M pixel auto-focus image
system that FOV is ±26° can be achieved. The MTF at half spatial frequency is above 25% , and the thickness of
the system is 8.2mm.
A miniature projecting system with dimension of 20 mm in length, 12 mm in width, and 10 mm in height suitable for
mobile devices is presented in this paper. This novel projecting system consists of an optical system with two lenses, a
liquid crystal display (LCD) device, a collimating tube, and a 1 W high power light-emitting diode (LED) with
wavelength of 525 nm. It projects a clear and bright image of 4.5 cm × 1.3 cm which displays 24 digits onto the palm at
a distance of 20 cm in a room with light on. The projector can be fabricated easily at low cost. Miniaturization is
achieved in this system so that it can be equipped into thin mobile phones.
Miniaturization is the key point to design image system for portable devices. Motor-driven lens technique is the
traditional way to achieve auto-focus and zoom functions. Nevertheless, systems with moving parts are difficult to
downscale. A solution presented in this paper has more potential to downscale and maintain high optical performance
simultaneously by combining reflective optics and MEMS deformable mirror. The system we designed with MEMS
deformable mirror is a 2M pixel auto-focus image system which is only 5.4mm in thickness before packaging and
6.7mm in thickness after packaging.