| 摘要 |
PROBLEM TO BE SOLVED: To illuminate a target two-dimensional pattern with proper brightness regardless of distance while saving power.SOLUTION: A two-dimensional pattern reading apparatus 1 comprises: image reading means 3 for reading a two-dimensional pattern that is a subject through two-dimensional image recognition; illumination means 2 for illuminating the subject; range finding means 16 for measuring distance to the subject; and radiation width change means 5, 11 and 12 for changing radiation width of light emitted from the illumination means on the basis of range-finding result of the range finding means. The radiation width change means makes the radiation width narrower as the distance to the subject extends. |
