| 摘要 |
A laser beam (L50) generated by a laser light source (50) is reflected by a light beam scanning device (60) and irradiated onto a hologram recording medium (45). An image (35) of a dispersion plate is recorded as a hologram on the hologram recording medium (45) by using reference light focused onto a scanning origin point (B). The light beam scanning device (60) bends the light beam (L50) at the scanning origin point (B) so as to irradiate the light beam (L50) onto the hologram recording medium (45). At such time, scanning is performed in such a way that the mode of bending the laser beam changes over time so that the location at which the bent laser beam (L60) is irradiated onto the hologram recording medium (45) changes over time. Irrespective of the location at which the beam is irradiated, a diffracted beam (L45) from the hologram recording medium (45) reproduces, at the same location, a reproduction image (35) of the same dispersion plate. An illuminated spot, which has a spectrum that is restricted by the reproduction image (35) of the hologram, is formed on a light-receiving face (R) of an object being illuminated (70). |
