An electroholographic colour reconstruction by time division switching of reference lights

In this paper, we report an electroholographic reconstruction method for a colour three-dimensional (3D) object, using the time division switching of reference lights. We use a reflective liquid crystal display (LCD) panel with a high refresh rate as a spatial light modulator. A colour 3D object is divided into red, green and blue components, from which we compute three computer-generated holograms (CGHs). The LCD panel displays the CGHs in sequence at a refresh rate of about 100 Hz. The LCD panel also outputs synchronized signals, indicating that one of the CGHs is currently displayed on the LCD panel. Red, green and blue light emitting diodes (LEDs), as used for reference lights, are switched by the synchronized signals. As a result of the afterimage effect on human eyes, we can clearly observe a coloured 3D object.