3) OBJECTS OF THE INVENTION:

The proposed invention is a method of upgradation of the True colour LED Displays to 3D technology by enhancing the display capabilities and adopting suitable techniques for 3D viewing. The method employs the active shutter technology to realise the 3D viewing experience.

4) BACKGROUND ART or PRIOR ART:

True colour LED displays are proven medium for Event coverage, Theatre backdrops, Advertisements, Mass communication and various other audio - visual applications for both indoor and outdoor environments. LED TVs in the real sense are bound to be a reality, especially for OOH applications. Similarly LED screens can be deployed for outdoor applications in drive-in theatres and for very large scale viewing. LCD and Plasma display devices are essentially TVs used for infotainment in homes, offices and recreation centres. All these are basically 2D displays.

3D viewing is a unique experience by itself. The uniqueness will be accentuated in respect of TV viewing, in movie applications and also in video conferencing and other mass communication applications. The true colour LED screens are basically 2D displays; however, in one embodiment, by a suitable physical re-arrangement of the modular screen segments spread out in the third (depth) dimension, large integrated theatre backdrops have been realised visualising excellent 3D effects. Commercial models are in the market.

The following co-pending patent applications by the inventor describe the processes in detail for several typical applications of the true colour LED Displays - LED DigiPoster; LED TV; LED screens to function as back drops for Theatre applications simulating 3D effects; and 3D Viewing experience through true colour LED Displays using passive polarised glasses'.

Intelligent LED 'Poster' System - LED DigiPoster 2621/CHE/2008 dt 28.10.2008
LED TV 2141/CHE/2009 dt 04.09.2009

A 3D display / video backdrop comprising of
LED display for theatre stage or TV/FILM
Production studio 2523/CHE/2010A dt 30.08.2010

3D Viewing experience through true colour LED
Displays using passive polarised glasses 3783/CHE/2010 dt 10.12.2010

LCD and Plasma display devices are presently being equipped with 3D technology but with limitations in respect of screen size, viewing angle and viewing distance.

5) SHORTCOMINGS:

True colour LED video displays are essentially 2D devices but possess several inherent merits like high intensity, brightness, colour, contrast, sharpness of image, viewability from a distance, daylight visibility and wider view angles and above all, modular in construction, which facilitate easy integration to realise larger screens of virtually any (unlimited) size and shape. These characteristics of the True colour LED video displays make them an ideal choice for 3D upgradation to enjoy an exciting 3D viewing. Passive polarised glasses enable 3D viewing but the film needs to be affixed at both the LED display and the eye glasses. 3D LCD and Plasma displays have limited viewing angle, viewing distance and limited screen sizes.

The present invention overcomes these limitations in the prior art with unlimited screen sizes, large viewing angle and long distance viewing with day light visibility. Also the LED display does not require additional film on the screen; an IR / RF transmitter is arranged for synchronising the display and eye-wear.

6) SUMMARY OF THE INVENTION:

The present invention describes a method of viewing 3D using the active shutter technology - the 3D viewing experience in respect of true colour LED displays contemplated by deploying 'active' eye glasses - comprising mechanical shutters with on/off controls.

The perception of 'Depth' by the human opthalmic system is because of the fact that images of the object as perceived by the left eye and the right eye are distinctly different. The 'absorption' of these distinctly different images continuously by the human sensory system provides the feeling of depth and the 3D effect for all the objects of the world as we see them every moment of our lives.

The 3D viewing effect is brought about by hardware and software related to the display, content and auxiliaries like viewing glasses and the special purpose optical sheet that provides the auto- stereoscopic effect.

In order to realise the '3D effect', the 'content' also needs to be specially prepared with special cameras. The principle behind this special content is true delineation of the images for select viewing by the left and right eyes with true attentive viewing at defined and designated speeds.

Input formats

Three common formats are in use for 3D inputs:

Side-by-side 3D (Reduction of horizontal resolution): The screen of resolution 1280*720 will be having two 640*720 frames for the left and right eyes when it is horizontally polarized.

Top/ Bottom 3D (Reduction of vertical resolution): It is a vertical resolution that is reduced by half as the images for the left and right eye are stored on top of each other in a single frame; the screen of resolution 1280*720 will be having two 1280*360 frames for the left and right eyes when it is vertically polarized.

Frame sequential (Reduction of temporal resolution or page flip): It consists of alternating frames wherein each successive frame carries the image meant for the one or the other eye.

Passive glasses can be used for Side-by-side 3D inputs while Active glasses or shutter technology will be ideally suited for Frame sequential inputs.

Video processing

The video signal captured by different input interfaces is processed for de-interlacing; scaling, including sharpness improvement; and the frame rate conversion. This is followed by the display- signal-processing technologies, such as contrast, brightness and saturation. Finally display-specific signal processing functions are carried out.

7) DESCRIPTION

There are three methodologies deployed in 3D technology - passive (polarised) or active (with shutters synchronized to the frame rate of the display) glasses - for viewing indoors; and specially constructed lenticular lenses used in conjunction with the stereoscopic display for outdoor viewing without glasses. Creating the illusion of 3D relies on the fact that two eyes of human being are separated by a particular distance. If each eye sees the image view of the same object viewed in the right eye and left eye exclusively, then the brain combines the images to make it appear three dimensional.

Passive glasses selectively enable the two eyes to see images of the screen in two different angles. Active glasses enable to see the image in two frames - one after the other - in quick succession and in synchronization with the screen with the help of ER. / RF means. Passive Polarised filter glasses are employed for viewing 3D movies in theatres and on the television sets at homes. Passive Polarised filter films are affixed on the true colour LED displays and also on the eye glasses to view 3D content.

LED display is organised in the form of rectangular matrix of LED pixels made up of either 3-in-l chip LED (for indoors) or a cluster of 3 or 4 leaded LEDs( for outdoors). By a suitable scheme it is possible to display the left and right images in a sequential manner on a regular display screen. However, since the effective frame rate is reduced to half, the displays are to be refreshed at double the refresh rate of standard displays, i.e at a minimum frame rate of 120 frames per second- Shutter glasses make the distinction between the images so that each eye only sees the corresponding image on the screen.

Each eyepiece of the special active shutter glass acts as a shutter and the left and right eye pieces are shuttered alternatingly in a synchronized manner so that each eye only sees the corresponding image being displayed on the screen. It is important to synchronise the active shutter glasses with the display so that the active shutter glasses allow the left eye to view the screen at the same moment when the frame corresponding to the left eye is being displayed on the screen. Subsequently, the active shutter glass has to switch the eyepiece for the right eye on so that the viewer can now view the next frame intended for the right eye. The active shutter glasses are maintained in synchronisation with the Display using infrared or radio technology.

Without the use of the 3D glasses, 3D images appear blurred and may at times become almost unwatchable.

Thus, in the case of Active shutter displays, the frame sequential 3D video is directly displayed on the screen.

The true colour LED Display products that are targeted for 3D viewing thus fall into 3 classes: Indoors - OOH - LED TV which is a 75"/85"/110" TV with 3mm, 4mm or 6mm pixel pitch; Indoor LED Displays for use in Movie theatres / Function halls with resolutions of 9mm, 12.7mm and 15mm; and Outdoor applications like functions / events / drive-in theatres and public gatherings with the pixel pitch ranging from 6mm, 9mm thru 12.7mm / 14mm / 21mm / 25.4mm to 40mm.

As an alternative to the mechanised shutter glasses, active eye-glasses may also be constructed using a special type of glass material which has an intrinsic property of switching between transparent and opaque modes in response to the IR / RF signal from display, for deployment in 3D viewing. Such materials are still under development and when available, the construction of the active glasses is simplified dispensing with the mechanical system.

8) TARGETED SPECIFICATIONS;

1. Indoors & Out Of Home (OOH)
Sizes Modular - Ranging from 51" up to 110" (for LED
TV configurations) or larger
Pixel 3-in-l chip LED (SMD)
Pixel Pitch 9mm, 6mm, 4mm and 3mm
Resolution (Typical) 288 x 192 pixels of 6mm pitch on 6' x 4' board
(85"diagonal)
Noofchip LEDs 55296

2. Inputs Live 3D Camera, Cable or Stored 3D content
3. Audio Supports Commercial Sound Systems
4. Installation Indoors : Uni-pole or Bi-Pole mounted
5. Content 3D content fed to display
6. Power Operates on 230V AC / Generator
7. Eye glasses With mechanised shutters operating in sync with display in IR / RF with receivers fitted
8. Sync control IR for smaller distances and RF for longer distances
9. Additional facilities on the display Sync signal transmitter generated for every frame

9) CLAIMS:

We Claim:

1. A method of viewing 3D content on the conventional 2D True Colour LED Video Displays deploying remote controlled mechanised active shutters at the eye glasses.

2. The method of claim 1, wherein the conventional 2D True Colour LED Video Display is suitably modified by means of the provision of an IR or RF signal transmitter to synchronise the shutter glasses with the frames being displayed.

3. The method of claim 1, wherein the conventional 2D True Colour LED Video Display, with the attachment made as above, presents two different frames of the image to the viewer in quick succession and also communicates to the active eye glasses for corresponding on I off operation on the shutters through the transmitter.

4. The method of claim 1, wherein, a receiver fitted on the eye glasses effects the on / off operation of the shutter on receiving signals from display..

5. The method of claim 1, wherein the input to the display is 3D content.

6. The method of claim 1, wherein, the pixels of the LED display are made up of 3-in-1 SMD chip LEDs for use in indoor applications only.

7. The method of claim 1, wherein, the IR is used to provide communication between display and the eye glass for shorter distances and RF for longer distances.

8. The method of claim 1, wherein, as an alternative to the mechanised shutter glasses, active eye-glasses may also be constructed using a special type of glass material which has an intrinsic property of switching between transparent and opaque modes in response to the IR / RF signal from display, for deployment in 3D viewing. Such materials are still under development and when available, the construction of the active glasses is simplified dispensing with the mechanical system.

9. The method of claim 1, summarises the scheme to experience 3D viewing on the True colour LED Video displays with active shutter filters at the eye glasses.