| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify the configuration of a hologram element. SOLUTION: A plurality of CGHs 1-5 are arranged and formed in a CGH pellet 10 in a circumferential direction so that they may not face each other across the center of a circle, and each diffraction angle is formed so that each diffracted image of the CGHs 1-5 may turn to a common prescribed position. A hologram element 16 is composed so that the light of a light source may be diffracted and the diffraction angle of the±1st order diffracted light may turn to the direction of the CGHs 1-5. When the +1st order diffracted light of the hologram element 16 is positioned so as to turn to the CGH 1 for example, the diffracted image is generated from the CGH 1 to be projected on a screen 15. Because the CGHs 1-5 are not formed so as to face each other across the center of a circle, other CGHs 2-5 do not exist in the position where the 1st order diffracted light turns, the diffracted images of the CGHs 2-5 are not generated and are not projected on the screen 15.</p> |
