| 摘要 |
A laser beam generated by a laser light source is reflected by a light beam scanning device, and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin. The light beam scanning device bends the laser beam at the scanning origin and irradiates it onto the hologram recording medium. At this time, scanning is carried out by changing the bending mode of the laser beam with time so that the irradiation position of the bent laser beam on the hologram recording medium changes with time. Regardless of the beam irradiation position, diffracted light from the hologram recording medium reproduces the same reproduction image of the scatter plate at the same position. An illumination spot in which speckles are reduced is formed on the light receiving surface of an illuminating object by the reproduction image of the hologram. |
