Alternative mechanical interfaces for alignment of image sensor and lens in surveillance cameras

To manufacture better cameras at lower costs is of great interest to the surveillance industry. Inthe process of manufacturing cameras, the mounting of the optics and the digital image sensor, isa crucial part of producing a high quality image. For high resolution cameras, mechanical passivealignment of the optics and image sensor is insufficient for producing a picture of adequate quality.This is caused by inherit problems from manufacturing, resulting in performance issues for theparts. For the lens, these performance issues causes the light path to deviate and the focal pointto be off center. In the same way, manufacturing of the image sensor causes similar problems.These problems results in an image of subpar quality, if the interface solely relies on mechanicalpassive alignment. To compensate for these problems a computer aided machine is used to alignthe lens and the image sensor. The lens and the sensor, are placed in the machine, aligned forbest possible image quality and fixated in its place. This fixation is done with UV light curedadhesive. The process is drawn with some issues, the curing of the adhesive causes unpredictableshrinkage that affects the image quality. In addition, contaminations such as dust or dirt on theparts, are impossible to remove once the fixation is complete, causing blemishes on the images.These faults results in scrapping of expensive parts, which is costly for the manufacturer. Thisthesis aims to find alternative mounting solutions to the parts, that result in less scrapping ofexpensive components, without sacrificing image quality. The result is two concepts that can beused as inspiration for future improvement of surveillance camera manufacturing. A new adhesiveinterface, that can reduce, manufacturing cost and the unreliable shrinkage of the adhesive, as wellas a new mechanical coupling that allows reassembly after cleaning, is presented.ii