Friday, March 08, 2019

2-sided Lensless Sensor

It still remains to be seen whether lensless image sensors are able to find a market beyond the under-display fingerprint applications. Meanwhile, Tokyo Institute of Technology and Shuzuoka University propose a 2-sided version of lensless imager in a Preprint paper "Super Field-of-View Lensless Camera by Coded Image Sensors" by Tomoya Nakamura, Keiichiro Kagawa, Shiho Torashima, Masahiro Yamaguchi.

"A lensless camera is an ultra-thin computational-imaging system. Existing lensless cameras are based on the axial arrangement of an image sensor and a coding mask, and therefore, the back side of the image sensor cannot be captured. In this paper, we propose a lensless camera with a novel design that can capture the front and back sides simultaneously. The proposed camera is composed of multiple coded image sensors, which are complementary-metal-oxide-semiconductor~(CMOS) image sensors in which air holes are randomly made at some pixels by drilling processing. When the sensors are placed facing each other, the object-side sensor works as a coding mask and the other works as a sparsified image sensor. The captured image is a sparse coded image, which can be decoded computationally by using compressive-sensing-based image reconstruction. We verified the feasibility of the proposed lensless camera by simulations and experiments. The proposed thin lensless camera realizes super field-of-view imaging without lenses or coding masks, and therefore can be used for rich information sensing in confined spaces. This work also suggests a new direction in the design of CMOS image sensors in the era of computational imaging."


  1. Are the under-screen fingerprint sensors really lensless image sensors? I thought they were using Qualcomm's ultrasonic fingerprint technology.

    1. There are optical and ultrasonic ones. Most are optical. They are lensless.


All comments are moderated to avoid spam and personal attacks.