| 摘要 |
With the use of a hologram(H) located in front of a picture screen (B), a diode laser(DL) illuminates it. When a user moves sideways, arrows or other symbols are visible, indicating the direction in which the user should move to be correctly positioned in front of the screen (B). It is also possible for the hologram picture to present an opaque frame, whereby the screen is invisible when faulty positioning occurs. - The position indicator can also take the form of a honeycomb structure, in which a position picture can be seen through the honeycomb tubes, e.g. a colour or a text, but if the honeycomb is moved slightly, the tube walls only are seen. Further variations involve the use of liq. crystal displays, Fresnel lenses, and Moire patterns. |
