A one-day course on 3DTV, the first of its kind, was held at the College of North West London, earlier this month.
The course was attended by TV engineers engaged in television reception and broadcasting from different parts of the UK.
Samsung was represented by their European Product Support manager.
‘3D television is now a commercial reality that is expanding rapidly’ said course tutor Fawzi Ibrahim. ‘Today it is essential for engineers and technicians working in the field of television to be familiar with the principles behind 3D and its applications to television broadcasting, streaming and reception’.
‘The response to the course was very pleasing and the feedback very extremely encouraging’ said Ibrahim. ‘Another course is planned for 16th July this year’.
Organised by TV Diagnostics, the course covered the principles behind our perception of depth through stereoscopic 3D techniques: active and passive, 3D encoding: frame compatible format, 2D + Depth techniques, 3D displays: spatial and sequential, Micro-polariser (uPol) and culminating with examining block diagrams and schematics of commercial 3D TV receivers, LCD and plasma.
The course ended with a hands-on session to back up the theory, examined various waveforms and testing voltage levels with a spot of fault finding using both plasma and LCD 3D TV receivers.
Course tutor Fawzi Ibrahim is author of several books on television and video technology and he describes how manufacturers are implementing 3D technology in their TVs:
The stereoscopic 3D technique presents the viewer with two separate images: one for the right eye and another for the left eye representing the two images that would be viewed by the right and left eyes.
The idea is to create the illusion of depth by shifting the objects to the left or to the right relative to the other image. When the two images are shown simultaneously to the respective eyes, this displacement produces a retinal disparity, or parallax causing or the perception of depth.
The original encoding of the two images relied on what is known as ‘colour shifting’ in which the left and right images are colour coded using a pair of colours such as red/green or red/cyan.
It produces the lowest quality 3D image compared with any of the other systems and hence has been shunned by manufacturers.
Instead, 3D broadcaster have opted for a frame packing system known as frame-compatible format in which the two left and right images are squeezed into a single 1920 x 1080 HD frame.
As for the actual display panel, some manufacturers (Samsung, Sony and Panasonic) went for conventional plasma or LCD 2D panels to display the left and right images sequentially. This requires the viewer to wear active glasses to shut alternate lenses in sync with the left and right sequence.
LG and JVC opted for an expensive new panel with a micro-polariser attached to the front. Both images are displayed simultaneously on alternate pixels or alternate lines.
Each image is then lined up behind different polarisers on the screen. All that is then required to view the 3D image is a simple pair of polarised glasses, with the appropriate polarisation mode in each lens.
Manufacturers are working on the second generation 3D TVs using a display screen capable of delivering multiple views from different perspectives, not just a single pair of left and right images, but eight or more images of the same scene captured from different positions; all of that and without the need for glassware.
