Glasses-Free Tabletop 3D Display for omnidirectional viewing by multiple viewers has been successfully developed.

－ Floating virtual 3D objects appearing on a flat tabletop surface－

July 1, 2010

The National Institute of Information and Communications Technology (NICT, President Dr. Hideo Miyahara), Universal Media Research Center in Keihanna Research Labs has developed a novel table-style 3D display called “fVisiOn.” The 3D display floats virtual 3D objects on a blank flat tabletop surface like a centerpiece and allows multiple viewers to observe the standing 3D images from any angle without the use of 3D glasses. Its observation style is especially designed for tabletop tasks assuming seated condition.

Background

As elemental technologies for establishing ultra-realistic communications, NICT, Universal Media Research Center in Keihanna Research Labs (Kyoto, Japan) is researching and developing various auto-stereoscopic 3D displays which do not require the use of special 3D glasses. When considering auto-stereoscopic 3D displaying techniques which are able to display virtual objects on a flat tabletop surface, existing displaying methods such as conventional TV-like 3D displays and volumetric displays are not suitable because of the following limitations. The former can merely provide depth information and its viewing area is usually only in front of the screen. Although the 3D images should be observed from any directions of 360° with correct perspective by multiple viewers, such displays limit the numbers of viewers and viewing area for table-like use. On the other hand, the latter requires a number of bulky mechanical gimmicks on the table, which invade the working space. Therefore, volumetric displays disturb usual tabletop tasks such as exchanging of documents on the table.

New Achievements

The developed novel technique canfloat standing 3D image on a blankflat tabletop surface, and allow multiple viewers to observe the 3Dfrom omnidirection of 360° in seated condition. It is designed to be a friendly interface for multiple users for varied tabletop tasks by featuring our glasses-free method and observation style.

For generation of the 3D images, fVisiOn employs a newly developed special optical device as a screen and a series of micro projectors arranged circularly. The combination of those devices reproduces a light field in a certain volume on the table. The light field represents a bunch of directional rays radiated from surfaces of objects which are assumed to be on the table. The light field of our method is optimized for observing in seated condition. In other words, the fVisiOn’s viewing area occupies an oblique position above the table. Additionally, our entire 3D imaging mechanism is installed underneath the table. It keeps the tabletop area clear and does not disturb collaborative work and natural communications. For example, fVisiOn can display virtual 3D images beside printed documents and physical mock-ups (Figure 1.)

The developed system is a prototype to validate a 3D generation principle we proposed. It employs a conical-shaped optical device and 96 projectors, and covers the viewing area of approximately 120° around the table, though it is 1/3 of ideal implementation. This primal prototype can float the 3D images of a height of approximately 5 cm on the tabletop surface like a centerpiece in the center of the table (Figure 2.)

Future Plans

n the future, we intend to develop an entire 360° viewable tabletop 3D display. The current obtainable 3D images are rather blurred and unfocused. In a future configuration, the image quality will be refined by improving optics characteristics and applying a correction method for the projected images. Moreover, we will tackle a study to enlarge the generated 3D images. Our developed technique befits for supporting common tabletop communications because the ring-shaped viewing area is formed around the table for seated condition, which generally be seen in a communication when seated at a roundtable. Another example is to support operations based on the geographic information such as urban planning, traffic control and disaster prevention. The system also promises to be adequate for the medical field, i.e. informed consent and simulation of operations. As a one of the ultimate goals, this technique has a possibility to construct a 3D arena because the observation style of a stadium is similar to this system.

Academic Presentations and Exhibits

The academic presentations of fVisiOn will be made at “3D Image Conference 2010” to be held on July 8-9 at the University of Tokyo, Japan and at “SIGGRAPH 2010” to be held on July 25-29 in Los Angeles, USA. We also plan a public exhibition in “Keihanna Research Fair” to be held in Kyoto, Japan in coming autumn.

Supplementary Information

Figure 1.

3D image produced by a glasses-free tabletop 3D display “fVisiOn”
The bunny in the center of the photo is 3D CG, a virtual object. The others, a pen, a document and a paper crane, are real objects.

Figure 2.

Photos of produced 3D images shot from three different angles
From above, a teapot and a toy duck of 3D CG shot from front side and angle of ±60°. The bottom is a 3D CG bunny with a real paper crane.

Glossary

Volumetric display

One of the techniques to display a volumetric 3D image seen from any direction of 360°. Those systems generally employ a screen which is rapidly rotating or sweeping in a certain volume, and project synchronized cross-sectional 2D images on the screen’s position and posture in the volume. To avoid touching the screen of rapid scanning, the systems are usually covered by a glass case and untouchable 3D images can only be displayed inside the case. Moreover, invading the space of the tabletop is another drawback to be solved for tabletop use because the systems require huge mechanical gimmicks on the table.

Appendix

Figure A-1.
Illustration of tabletop 3D display.

A tabletop, which is an area of the table surface, is a shared space for collaborative work and is useful for varied tasks. When multiple users are performing shared tabletop tasks, separate images with correct viewing perspectives should be provided in each user’s direction. Our 3D displaying technique can support such communications naturally by displaying 3D images beside documents or real objects. It is useful not only for face-to-face communication but also for remote and multi-user collaborative work.

Figure A-2.
General viewing area of ordinary methods and our ring-shaped viewing area.

Viewing area is an area which is designed for observing 3D images with correct perspective. Ordinary methods are generally designed to be viewed perpendicularly.
Therefore, the viewing area is formed only within a narrow range from the normal of the display. Our newly developed method produces the parallax of depth perception in the direction of a circular path of a horizontal plane located above the table. When the both viewer’s eyes are on the ring-shaped viewing area, he/she is able to observe the 3D images at the center of the table without the use of 3D glasses.