The Principle And Manufacture Of Micro Visual Tag

The new optical system of micro visual tag is based on the principle of defocus blur. Unlike current optical tag, such as barcodes, must be read within a short rang and the codes occupy valuable physical space on products, this tag can be shrunk to several millimeters and captured from a distance of over 0.1 meters. It is integrated with LED, lens and the 2D barcode mask to form an active signal transmitter. Taking using of the camera out of focus, the users are able to detect small optical tag from a relatively large distance and get an amplificatory image. The image is accurately decoded to access to information. The parameters of the transmitting terminal are related to the parameters of camera lens. The simulations and experiments show that the aperture, focal length and light source have influence on the detection range. For the virtues of QR Code such as High-Speed omnibearing reading and high-efficiency coding Chinese character, it is selected as the mode of information encoding.The primary content and innovation of the dissertation includes the follows. Firstly, this paper puts forward a new tag system. It is different from the traditional barcode which has the flaws such as occupying too much space, low amount of information, easy defilement and short detecting range. The advantages of the tag such as large amount of information, security and cheapness make it possible to provide an effective supplement to radio frequency tags. Secondly the integrated micro visual tag like LED simplifies the process and reduces the production costs. This creates the condition for future large-scale 1 and application. At last we produce the mask by photoplotter. With the advantages of high accuracy, processing convenience and less fouling, the photoplotter can produce high-density mask whose smallest symbol is up to 870μm, so it is possible to enhance the integration and increase the detection range.