1. Field of the Invention
The invention relates to a three-dimensional display device and a displaying method using the same.
2. Discussion of the Related Art
A two-dimensional display device is generally used. Recently, because of wideband communication networks, a three-dimensional display device has been researched and developed.
There are various types of three-dimensional image displays, for example, a holographic image type, a stereographic type, a volumetric type and the like.
The holographic type is used for a holographic image using a laser or a white ray.
The stereographic type display device displays a three-dimensional image using binocular parallax. The stereographic type display device includes a display device that uses specific glasses and a display device without glasses. The stereoscopic display devices without glasses are divided into a parallax barrier type, a lenticular type, and the like.
The volumetric type is used for three-dimensional computer graphics or an I-MAX movie. Of volumetric types, a floating image display device is suggested. The floating image display device displays a floating image using a rotating screen. Different images in various directions are projected on the rotating screen, and viewers perceive the different images.
FIG. 1A is a conceptional view illustrating a floating image display device according to the related art, and FIG. 1B is a perspective view illustrating a floating image display device according to the related art.
Referring to FIG. 1A, in the floating image display device 10, a screen 12 rotates in a cylindrical case. While the screen rotates 12, first to fourth partial images IM1 to IM4 in different four directions are projected on the screen 12, and viewers in the four directions view the respective four images IM1 to IM4.
In other words, when the viewer turns around and looks at the screen 12, the viewer perceives as if the viewer really were viewing a three-dimensional object in various directions.
In detail, referring to FIG. 1B, the floating image display device 10 includes the rotating screen 12, a projector 14, a motor 16, a first mirror M1, and a plurality of second mirrors M2.
The screen 12 can rotate 360 degrees, the projector 14 projects a plurality of partial images IM1 to IMn on the first mirror M1, and the first mirror M1 reflects the plurality of partial images IM1 to IMn toward the plurality of second mirrors M2. The plurality of second mirrors M2 reflect the plurality of partial images IM1 to IMn, respectively, toward the screen 12. When the screen 12 rotates and faces one of the plurality of the second mirrors M2, the viewer in a direction of the one of the plurality of second mirrors M2 views the partial image corresponding to the one of the plurality of second mirrors M2.
Accordingly, the viewer turns 360 degrees and perceives different partial images. When the plurality of partial images IM1 to IMn are made as different images for a three-dimensional object viewed in various directions, the viewer perceives as if the three-dimensional object existed.
However, because the related art floating image display device needs the motor 16 to rotate the screen 12, power consumption is much, and volume and weight of the display device increase. Further, because the second mirrors M2 and the screen 12 are located in different structural components of the display device, accuracy of reflecting angle decreases and quality of the image viewed by the viewer decreases. This problems increase with vibration due to rotation of the motor 12.