Wide-angle camera with multichannel architecture using microlenses on a curved surface

Abstract

We propose a multichannel imaging system that combines the principles of an insect's compound eye and the human eye. The optical system enables a reduction in track length of the imaging device to achieve miniaturization. The multichannel structure is achieved by a curved microlens array, and a Hypergon lens is used as the main lens to simulate the human eye, achieving large field of view (FOV). With this architecture, each microlens of the array transmits a segment of the overall FOV. The partial images are recorded in separate channels and stitched together to form the final image of the whole FOV by image processing. The design is 2.7 mm thick, with 59 channels; the 100°×80° full FOV is optimized using ZEMAX ray-tracing software on an image plane. The image plane size is 4.53 mm×3.29 mm. Given the recent progress in the fabrication of microlenses, this image system has the potential to be commercialized in the near future.

Wide-angle and ultrathin camera module using a curved hexagonal microlens array and all spherical surfaces

“…The fabrication of the MLA on a spherical surface by multireplication processes has been demonstrated in our previous research [6][7][8][9], and practical production of the MLA is feasible. A hexagonal microlens is used to avoid the light leakage problem.…”

“…In addition, each of the microlenses has its own distortion, so we removed the trimmed images as much as possible. We eventually stitched every small partial image into a combined image after photo trimming [9].…”

“…Generally speaking, it is difficult to fit a wide-angle lens structure in such small form factor, because the thickness, light incident angle, image quality, and pixel number of a mobile phone camera influence each other [5]; furthermore, most mobile phone cameras use four to six lenses. To overcome these drawbacks, we adopt a curved hexagonal microlens array (MLA), which can be made by micromachining processes [6][7][8][9][10]. The MLA is composed of multiple lenses arranged in a two-dimensional array on a supporting substrate.…”

Biologically Inspired Ultrathin Contact Imager for High‐Resolution Imaging of Epidermal Ridges on Human Finger

“…[ 12–14 ] The curved configuration often exhibits microlens arrays (MLA) on hemispherical shapes using complicate fabrication methods such as integration with curved complementary metal oxide semiconductor (CMOS) image sensor arrays (ISA) or additional optical relay components to guide light to planar CMOS ISA. [ 15–20 ] The curved configuration can provide a large FOV but has low resolution and it is very difficult to manufacture at the wafer‐level. [ 15,16 ] In contrast, the planar configuration facilitates the wafer‐level fabrication as well as the compact camera packaging.…”

A lab-on-phone instrument with varifocal microscope via a liquid-actuated aspheric lens (LAL)

“…On the other hand, aspherical lenses are widely used and have the advantage of aberration correction of performance [ 25 ]. In particular, aspherical lenses are very efficient in correcting spherical coma and longitudinal spherical aberration (LSA) [ 26 ], distortion in wide-angle lenses of camera [ 27 ], intraocular lens (IOL) [ 28 , 29 ] and contact lenses or glasses design [ 30 ]. Furthermore, by integrating the aspheric lenses with adaptive lenses, spherical aberration can be minimized [ 31 ].…”