Replacers of barcodes for small application areas by using grating dots to diffractively form bright points.
Although barcodes can be used to manage data conveniently, they cannot be applied to small areas. Therefore, pointcodes are used to overcome the issue in this article. A pointcode uses a pointcode pattern to encode data and uses a pointcode image to decode data. A pointcode pattern is composed of many grating dots with different specified grating pitches and grating orientations. Moreover, there are two grating-dot sizes generated. When a laser beam illuminates a pointcode pattern with correct illuminating conditions, a pointcode image corresponding to the hidden data is diffractively reconstructed. A pointcode image is composed of many bright points with different positions. There are two possible bright-point sizes generated. A bright point or two bright points at specified positions are used to denote a number. Small pointcode patterns are enough to diffractively form pointcode images.
Yeh
Sheng Lih
SL
Department of Mechanical Engineering, Lunghwa University of Science and Technology, 300, Section 1, Wanshou Road, Kueishan, Taoyuan County, Taiwan. slyeh@mail.lhu.edu.tw
Yang
Hung Jen
HJ
Lin
Shyh Tsong
ST
Wu
Ming Wei
MW