We present a tutorial approach to understanding the ancient process of stereo photography. A simple transformation of object space allows the complete recording and viewing system, typically independent functions with a non-optical step, to be represented as an equivalent first-order optical system.
Tunable GRIN lenses that operate in randomly polarized light may be produced using liquid crystal (LC) materials. We describe one such device and discuss practical methods of evaluating its performance, considering its dependence on polarization.
Camera modules in mobile devices have become ubiquitous, and the optical design and fabrication technology behind them is underappreciated. We will present a basic summary of the technology and discuss some recent developments that may influence future camera designs.
Designing lenses for cell phone cameras is different from designing for traditional imaging systems; the format poses unique challenges. Most of the difficulty stems from the scale of the system, which is based on the size of the sensor.
We present the design of a compact, low-cost finger imager, to be used for enrolling and recognizing individuals based upon their finger ridge patterns. The optical system employs viewing beyond the critical angle and darkfield illumination for maximum image contrast. The optical system is afocal and telecentric, achieving corrected distortion with oblique viewing.
This paper discusses the optical and opto-mechanical design of a new laser head developed at Polaroid for printing Helios binary film for printing high quality medical hard copy images. The head is part of an external drum printer for 14' X 17' film. The pixel size is 84 X 84 μm, produced by four lasers, with the smallest printable spot 3 X 6 micrometer, to produce 4096 gray levels. Two pixels side-by-side are simultaneously printed. The head has eight independent 840 nm diode lasers manufactured by Polaroid. Each laser emits up to 1.1 W over an emission length of about 100 μm, with a particularly uniform nearfield irradiance. The lasers are microlensed to equalize the divergences in the two principal meridians. Each packaged laser is aligned in a field-replaceable illuminator whose output beam, focused at infinity, is bore-sighted in a mechanical cylinder. The illuminators are arranged roughly radially. Eight lenses image the laser nearfields on a multi-facet mirror produced by diamond machining. The mirror facets truncate the beams to give the desired pixel shapes and separations. A reducing afocal relay images the mirror onto the film. The final element is a molded aspheric lens, mounted in an actuator to maintain focus on the film. The focusing unit also comprises a triangulation-based focus sensor. The alignment procedures and fixtures were devised concurrently with the head for manufacturing simplicity. The main physical structure is a casting, into which reference surfaces are machined. All optical subassemblies are attached to this casting, with a mixture of optical alignment and self-location. Semi-kinematic cylinder-in-V methodology is utilized. The active alignment steps are done in a sequence that tends to reduce errors from previous steps.
We demonstrate that transmission kinoforms for visible light applications can be injection molded in acrylic in production volumes. A camera is described that employs molded Fresnel lenses to change the convergence of a projection ranging system. Kinoform surfaces are used in the projection system to achromatize the Fresnel lenses.
The design of two broadband hybrid diffrve-refrve optical systems a landscape type lens and a Schmidt telescope was investigated. The systems were achromatized using the large negative dispersion characteristic of kinoforms. In the scalar wave regime these strucwres can approach 100 efficiency for one object point and wavelength but efficiency inevitably decreases when these parameters change. We evaluated polychromatic image quality taking diffraction efficiency into account by constructing properly weighted geometric point spread functions from several diffracted orders and calculating modulation transfer functions. The MTFs of the hybrid achmmats were improved at high spatial frequencies but reduced at low frequencies because inefficiency caused diffrtion into non-design ders. 2.
The International Lens Design Conference (ILDC) has traditionally included one or more lens design problems for members of the design community to consider. 1''2''3 This year there are two: the Monochromatic QUartet and the NonLens. The problems are intended to be enjoyable and instructive for participants conference attendees and even for readers of these Proceedings! The NonLens was suggested by Professor Adriaan Waither of Worcester Polytechnic Institote. It is an unusual lens that requires the participants to determine the design form and optimization method that best satisfies the requirements. Furthermore it is of theoretical interest explained by Waither later in this paper. Eighteen individuals submitted twenty solutions. They are all included here along with several simple solutions that were generated for comparison. 1. The problem: A NonLens The following statement of the NonLens problem was distributed with the ILDC Call for Papers: 2. Background of the NonLens Prof. Walther sent a history of his interest in NonLenses which follows (slightly paraphrased) " As a graduate swdent in Deift I worked as a research assistant for A. C. S. van Heel. He was the man who. . . had revived the art of lens design in Holland. He played an important role in the creation of Oldelft company and had trained their original design staff. He was also a superb teher one of the old gentlemen of science. During and after the