Barry G Blundell FBCS

Research and writing

VOLUMETRIC IMAGES ON SCREEN

Video of 3D moving images created on a working early prototype of my Cathode Ray Sphere volumetric display (1994).

Some of my experimental work -

For comments on the Cathode Ray Sphere in Nick Sagan's book ("You Call This The Future?: The Greatest Inventions Sci-Fi Imagined and Science Promised", published in 2008), click here.

Section of a 3D printed wing structure

The ribs, front spar, and trailing edge are printed as a single entity using the laser sintering approach. The final wing of the model is printed in four parts. The overall weight approximates to that of an equivalent balsa wood structure.

Mirror, mirror on the wall..

Revisiting and re-evaluating the varifocal mirror display technique.

Stealth Bomber depicted on an early Cathode Ray Sphere (CRS) prototype.

An AutoCAD rendition of a Stealth Bomber depicted on one of the early CRS prototypes. This was naturally a static image, dynamic volumetric images tend to be much more impressive.

The Starship Enterprise,

This wireframe AutoCAD drawing further demonstrates the difficulty of photographing more complex translucent volumetric images.

An animated piston, crankshaft and connecting rod.

When volumetric images are photographed, only the pictorial depth cues are preserved - the oculomotor and parallax depth cues are lost. Consequently, by and large only simple images can be effectively photographed, and even in this simple case of a static photograph, the elegance of motion is not recorded.

The depiction of a mathematical function.

The majority of volumetric displays depict translucent images and this exacerbates the difficulty of photographing these images. However, image translucency is not an inherent feature of volumetric systems, and moreover when internal structure is of importance, the translucency of images can be beneficial. Ultimately there is a need to create volumetric systems in which the degree of translucency can be controlled.

One of the earliest CRS images.

The magnetic field in the vicinity of a current carrying coil.

A number of satellites in orbit around the Earth.

This type of application capitalises on the sound ability of volumetric displays to depict dynamic spatial information.

Taking a look at the first all-glass CRS prototype.

The phosphor-coated screen can be seen. This rotated at around 30Hz sweeping out a cylindrical image space. Voxels are activated using two electron guns employing electrostatic deflection.

The first Cathode Ray Sphere prototype at the University of Canterbury

Bob Young was instrumental in implementing the design.

The first prototype (prior to miniaturisation) of a multi-channel high bandwidth data transfer link.

For use with a volumetric 3D display employing the rotational motion of an active surface of emission or active display volume.

The first three-electron gun Cathode Ray Sphere prototype.

When the electron guns are taken below the equatorial position of the image space, three electron guns are needed to ameliorate the impact of the voxel elongation and voxel positioning dead zones.

A larger volume volumetric display in early prototype form which is designed to employ electron guns with final anode voltages of ~30,000 volts.

A system able to light up a room with 3D images! Prototype induction motor is from below and is located about the pumping system (this prototype was not designed to be evacuated and sealed off). The two-electron gun configuration is employed, and hence the equatorial electron gun positions.

Balloon flights to send electronic payloads to high altitudes – as final year undergraduate student projects.

At that time (mid-1990’s) the meteorological balloons were filled with hydrogen – but this is not really to be recommended without stringent precautions.

Again showing the inflation of the meteorological balloons at the US GHOST balloon hangar at Christchurch Airport.

Ready for launch.

Students worked as a team developing modular payloads comprising, for example, transducers, power management systems, data transmission systems, etc. Quickly learning the difference between developing working electronics in a lab, and electronics that would continue to work at an altitude of around 100,000 feet!

Up and away.

This work was complemented by projects involving the stabilisation of large model aircraft, by means of sensing the electrostatic field gradient, and also by tethered balloon systems. However, it was the high altitude balloon flights which really captivated student interest.

The control system for an Echelle spectrograph developed for use with the Anglo-Australian telescope.

The controlling hardware interfaced remotely with the spectrograph via a fibre-optic link. Early experience with so-called fail-safe systems, automated diagnostics, and built-in redundancy.

A typical microwave bridge spectrometer in the early years.

Prior to its automation, it required set-up times of several hours, and continual manual adjustment.

Control and data acquisition in the early years.

A multiprocessor (8 processors) system that I developed for use with a microwave double-resonance bridge spectrometer applied to chemical analysis.

A rat’s nest of wiring (wire-wrap techniques were used) in the system that I developed in the early 1980’s.

The system automated the control of all facets of the spectrometer, acquired data, processed the data, and presented it both numerically and graphically.