Artifical compound eyes - Different concepts and their application to ultra flat image acquisition sensors

Two different approaches for ultra flat image acquisition sensors on the basis of artificial compound eyes are examined. In apposition optics the image reconstruction is based on moiré- or static sampling while the superposition eye approach produces an overall image. Both types of sensors are compared with respect to theoretical limitations of resolution, sensitivity and system thickness. Explicit design rules are given. A paraxial 3×3 matrix formalism is used to describe the arrangement of three microlens arrays with different pitches to find first order parameters of artificial superposition eyes. The model is validated by analysis of the system with raytracing software. Measurements of focal length of anamorphic reflow lenses, which are key components of the superposition approach, under oblique incidence are performed. For the second approach, the artificial apposition eye, a first demonstrator system is presented. The monolithic device consists of a UV-replicated reflow microlens array on a thin silica-substrate with a pinhole array in a metal layer on the backside. The pitch of the pinholes differs from the lens array pitch to enable an individual viewing angle for each channel. Imaged test patterns are presented and measurements of the angular sensitivity function are compared to calculations using commercial raytracing software

International round-robin experiment for angle-resolved light scattering measurement

International audienc

An image restoration approach for artificial compound eyes

Natural compound eyes combine a small eye volume with a large field of view (FOV) at the cost of comparatively low spatial resolution. Based on these principles, an artificial apposition compound-eye imaging system has been developed. In this system the total FOV is given by the number of channels along one axis multiplied with the sampling angle between channels. In order to increase the image resolution for a fixed FOV the sampling angle is made small. However, depending on the size of the acceptance angle, the FOVs of adjacent channels overlap which causes a reduction of contrast in the overall image. In this work we study the feasibility of using digital post-processing methods for images obtained with a thin compound-eye camera to overcome this reduction in contrast. We chose the Wiener filter for the post-processing and carried out simulations and experimental measurements to verify its use

Bildsensor

DE 102007045525 A1 UPAB: 20090428 NOVELTY - The sensor (1') has image sensor units e.g. opto-electronic and/or digital units, with light-sensitive surfaces e.g. photodiode, in an array-like arrangement, where centers of the surfaces are junctions spaced to each other and span a two-dimensional network with horizontal and vertical connecting lines (12, 13). Distance between two junctions of the arrangement along one of the lines is different in a center region (5) and in a boundary region (6), and/or distance to the other line from the center region to the boundary region is changed such that the network forms a non-equidistant grid. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a camera system comprises an image sensor (2) a method for production of an image sensor. USE - Image sensor for use in a camera system i a portable telecommunication equipment, a scanner, a camera, an image detection equipment, terrestrial and star sensors, a satellite sensor, space flight equipments, a monitoring sensor for monitoring individual parts of an industrial system, a robotic sensor arrangement in microrobot, and a medical sensor arrangement (all claimed) as a vision aid in human eye and in a micro endoscope. ADVANTAGE - The distance between two junctions of the arrangement along one of the lines is different in the center region and in the boundary region, and/or the distance to the other line from the center region to the boundary region is changed such that the network forms a non-equidistant lattice, thus mutually avoiding restrictive aberration e.g. geometrical distortion, in the sensor. The utilization of the array-like arrangement reduces requirements to computation time and storage of required electronics

Mit den Augen einer Fliege

Seit Jahrmillionen ist das Facettenauge der Insekten ein Erfolgsmodell. Ihr Volumen ist sehr viel kleiner als das eines klassischen Ein-Linsen-Systems, das wir Menschen besitzen, und durch ihre große Tiefenschärfe kommt es ohne Autofokus aus. Nun haben deutsche Forscher ein künstliches Facettenauge entwickelt, das etwa 0,2 mm dick ist und eine Auflösung von 60 x 60 Pixel hat. Damit passt es beispielsweise auf Kreditkarten, Folien oder Displays