| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hologram information reader which performs reading of a diffraction direction, rotation direction and diffraction efficiency for all holograms within an effective visual field without depending upon their places. <P>SOLUTION: The hologram information reader includes the illumination means for irradiating the finite visual field width of a hologram surface by using a vertically movable annular point light source, a diffracted light imaging means for imaging diffracted light from the hologram section irradiated by the illumination means, and a pitch acquiring means to acquire the pitch of the diffraction grating from the diffracted light obtained from the diffracted light obtained by the diffracted light imaging means. The method of reading are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT |
