Study Of Non-contact Multi-spectral Hand Imaging Light System

With the rapid development of modern science and technology and the increasingly strong demand for production and living, the single-modal biometrics, which is limited, has been unable to meet people’s needs. This paper presents and designs an identification device which can put the collected three-modal feature of the palm-vein, palm-print and palm-shaped together in a multi-spectrum and non-contact condition. This device can solve the problem of traditional-touching unsanitary and infectious-disease. Meanwhile it overcomes the shortcoming for the lower single-modal recognition rate, and improves the identification system of overall performance more comprehensively and effectively.This device has the aspects of high-speed image processing with DSP, even Ethernet network communication. It designs the systems which collects hand three modal information for user identification based on the TMS320DM642 DSP chip, and equipped with LCD real-time display, and exchange data from DM642 to PC by the Ethernet interface.The whole hardware system include front-end data acquisition and back-end display and data transmission of two parts, the frontend acquisition system consists of infrared sensor, light source system, the image sensor acquisition module, DSP processing module; the backend system is mainly composed of LCD module, an Ethernet interface modules, voice module,ther peripheral circuits such as power modules and reset module;Its software includes various modules and the initial part of the driving hand limited area locator design, landing recognition algorithm and PC interface, etc. When the light source system designed, it have to be considered that the coverage-area, the uniformity of illumination, using the constant current chip(AMC7150) to control the light source. It uses the dual-image sensor(OV5116)to collect the hand-information, uses DM642 to complete the image processing. The data transmits from the VP port to the encoder chip, converts the signal D/A with coded chips,outputs analog signals into the LCD screen on display. The collected data comes through the hand image Ethernet media access controller(EMAC), process the data by the physical layer chip(PHY), sends to RJ45, completes the registration and other related work on the PC, and then sends the data-package back to DM642.