Adam J. Schwarz

The classification of volumetric display systems: characteristics and predictability of the image space

A diverse range of volumetric display systems has been proposed during the last 90 years. In order to facilitate a comparison between the various approaches, the three subsystems that comprise displays of this type are identified and are used as a basis for a classification scheme. The general characteristics of a number of volumetric display system configurations are examined, with emphasis given to issues relating to the predictability of the volume within which images are depicted. Key characteristics of this image space are identified and the complex manner in which they depend upon the display unit subsystems are illustrated for several current volumetric display techniques.

Cathode ray sphere : a prototype system to display volumetric three-dimensional images

Details are given on a novel type of display system based on traditional technology and capable of displaying truly three-dimensional computer-generated images that can be viewed concurrently from practically any orientation without the need for special glasses to be worn. The principle of operation is elucidated, data rate requirements are described, the prototype control system hardware is outlined, and pictures of some simple computer-generated shapes that have been displayed are included.

Considerations regarding voxel brightness in volumetric displays utilizing two-step excitation processes

By the examination of a simple three-level quantum system, the time-dependent rate-equation analysis of the two-step excitation of fluorescence is extended to include the effects of the intermediate state lifetime and of saturation pumping on the total number of fluorescent centers excited to the target state. Further, the results relevant to the implementation of such a process to a volumetric 3-D display device are emphasized, and the performance of a display medium is indicated with respect to brightness and data rate. Restrictions placed on the two-step system by the fact that they are no longer assumed to be pumped in isolation are discussed.

Optimizing dot graphics for volumetric displays

Discusses a dot-graphics plotting technique that allows a control system to read voxel data at a constant rate, despite the random-scan nature of the writing method. If we assume the data is arranged in consecutive slices, then the constrained 3D optimization problem reduces to a 2D one. In this article, we investigate and seek to optimize the efficiency with which the voxels within each slice are plotted, in order to reduce the memory requirements. Moreover, we consider the effect of changing the plotting order of the voxels within each slice to shorten the total beam path and thus the total time required to plot the voxels. This increases the total number of visible voxels displayed in the volume.

Regions of extreme image distortion in rotating-screen volumetric display systems

Abstract Volumetric displays create three-dimensional (3D) images within a display volume, rather than upon a stationary surface, and give viewers the freedom to view the image from virtually any direction, greatly facilitating group interaction with the displayed information. Since the images are physically three-dimensional, depth cues such as binocular and motion parallax are automatically satisfied (both horizontally and vertically). The image fidelity of such displays must be sufficiently high if they are to serve as useful visualisation tools. At present, the volumetric display techniques closest to commercial realisation utilise a rapidly rotating screen to sweep out the display volume. This may be addressed by an electron or laser beam. This technique, however, leads to significant image distortion in regions corresponding to the beam impinging upon the screen at very acute angles. These regions, known as dead zones, are analysed for screens of both helical and planar screen geometries with a variety of beam source positions, and means by which they may be circumvented are outlined. The suitability of interaction schemes such as joystick and glove input is discussed.