| 摘要 |
A hologram is disclosed, wherein an image of a ring shaped character string satisfying the following conditional formulas is reproduced: 4 Zf / H 4; |Zf / H| < Zr / H, where Zf is the depth-directional position of the front-most part of the ring character string, Zr is the depth-directional position of the rear-most part of the character string, H is the height of the ring-shaped character string, and | ¦| indicates absolute values. Also, a method of preparing a hologram is disclosed, comprising: defining an original image as a three-dimensional (3D) image, a hologram recording plane, and reference light for irradiating the hologram plane; defining a large number of arithmetic operation plane points, and arithmetically determining the interference wave intensity formed by an object beam from each object and reference light for each point. Physical interference fringes are prepared based on intensity distribution, the front-most image part being near the hologram recording plane. In addition, a hologram is reproduced with front-most image part within ±1 mm in front of the hologram plane, the rear most part within 2 mm to 20 mm at the plane back, these parts being 2 mm or more apart. |
