| 摘要 |
PURPOSE:To make the opening of a bar-code reading window small, by moving periodically an incident point of laser light to a hologram. CONSTITUTION:The incident position of incident beam X, Y and Z to a hologram 10 is changed in order of X Y Z Y X continuously in 1,000sec (t1- t5 i.e., t=0, t1=250, t3=500, t4=750 and t5=1,000sec), and in accordance with this, also exit beam x, y and z are changed in order of x y z y x. Then the angle made by means x, y which are made incident to one point P of the pupil of human eye and the angle made by the beam y and z are >=1.45 deg.(5X 10<-4>sr. calculated in terms of a solid angle) respectively. Therefore, even if entirely same scanning line is scanned over (n) times in a unit time, an incident point is divided in (n) pieces, and therefore the maximum permissible quantity of light is remarkably increased. |
