Laser TV

From Wikipedia, the free encyclopedia

This article contains information about a scheduled or expected future product. It may contain preliminary or speculative information, and may not reflect the final version of the product.

Laser TV is a proposed new video display technology using laser optoelectronics. Some claim that laser TVs will be commercially available in late 2007.^[1]

Contents 1 Technology 2 Advantages 3 Drawbacks 4 Controversy 5 External links 6 References

[edit] Technology

Lasers may become an ideal replacement for the UHP lamps^[2], which are currently in use in projection display devices such as rear projection TV and front projectors. Current televisions are capable of displaying only half of the visible spectrum of colors^[3].

A laser TV requires lasers in three distinct wavelengths: Red, Green and Blue. While red laser diodes are commercially available, there are no commercially available green and blue laser diodes which can provide the required power at room temperature with an adequate life time. Instead frequency doubling can be used to provide the blue and green wavelengths. Several types of lasers can be used as the frequency doubled sources: fiber lasers, inter cavity doubled lasers, external cavity doubled lasers, eVCSEL’s and OPSL’s (Optically Pumped Semiconductor Lasers). Among the inter cavity doubled lasers VCSEL’s have shown much promise and potential to be the basis for a mass produced frequency doubled laser.

A VECSEL is a vertical cavity, and is composed of two mirrors. On top of one of them is a diode as the active medium. These lasers combine high overall efficiency with good beam quality. The light from the high power IR-laser diodes is converted into visible light by means of extra-cavity waveguided second harmonic generation. Laser-pulses with about 10 kHz repetition rate and various lengths are send to a DLD where each mirror directs the pulse either onto screen or into the dump. Because of the well known wavelengths all coatings can be optimized to reduce reflections and therefore speckle^{[citation needed]}.

[edit] Advantages

One major claim of laser advocates is the ability to produce undiluted, perfect colors allowing precise hue mixing. With the color enhancement capable with lasers, up to 90% of the spectrum that is currently unviewable could be regained.^[3] Other improvements that laser advocates claim are bulbs that will never blow out, and increased efficiency by using two-thirds less power than traditional rear projection televisions.^[3]. Historically, however, lasers have been too bulky and expensive for widespread adoption.

The laser technology advocates claim that the technology will allow displays with a richer, more vibrant color palette than the conventional plasma, LCD or CRT displays.^[3]

They also claim the displays will:^[4]

• be half the weight and cost of Plasma or LCD displays
• require around 25% of the power required by Plasma or LCD displays
• be very thin like Plasma and LCD displays are today
• have a very wide colour gamut
• have a 50,000 hour life

[edit] Drawbacks

Together with the advantages of laser sources, there are reports that also describe some of the current shortcomings of laser displays,^[5] such as the following:

• Cost. Although a laser system can eliminate several components such as the color wheel and filters, the laser devices themselves are currently expensive. As manufacturing processes improve, however, this may be alleviated.
• Safety. The high power emitted by the coherent laser sources is inherently dangerous to human vision. Proponents claim that integrating the devices with the needed diffusion filters removes this risk.
• Speckle. Due to the narrowband coherent light source, speckle will be an issue at the display. This has also been a problem in laser lighting displays and has been solved through modulation of the light source thus widening the bandwidth and reducing the possibility for coherent interference. Proponents claim that this issue can be minimized by the use of diffusing elements and multiple sources. These, however, may impact displayed resolution and system cost.

---

[edit] Controversy

Some have questioned the credibility of Laser TV development efforts. Apparently, some information regarding Laser TV developments can be traced to the pre-IPO publicity campaign of Arasor^{[6] [7] [8] [9]}, and its partner, Novalux.^[10]

A number of major consumer TV manufacturers have indicated that they have no plans to incorporate Laser TV technology into their product ranges.^[11]

To the contrary however, companies such as Novalux have shown what appear to be viable demonstrations at industry conferences such as SID and CES.^{[12] [13] [14]}

[edit] External links

• supplier of VECSELs with optional SHG up to 1.5 W
• Laser-TV News and Infos

[edit] References

1. ^ Laser TV Technology: Plasma and LCD Killer. Gizmodo (2006-10-11). Retrieved on 2007-01-04.
2. ^ "What means LASER-TV?", Laser tv news. Retrieved on 2007-02-24.
3. ^ ^{a b c d} Morgenstern, Steve (2007). "Laser-Sharp Color". Popular Science 270 (1). 
4. ^ Forget plasma and LCD TV - the Laser TV is coming!. iTWire (2006-10-11). Retrieved on 2007-01-04.
5. ^ Brennesholtz, et al (2005-08-19). "Laser Projection Systems" (PDF). Insight Media. Retrieved on 2007-01-29.
6. ^ Mitsubishi PR/Marketing Ignorant of Laser TV 6 Months After Own Press Release. Smarthouse (2007-01-04). Retrieved on 2007-01-04.
7. ^ Mitsubishi Press Release Announcing Laser HDTV Demonstration. Mitsubishi (2006-04-07). Retrieved on 2007-01-04.
8. ^ More Problems For Laser TV Company Arasor. Smarthouse (2007-01-04). Retrieved on 2007-01-04.
9. ^ "Laser TV unveiled in Australia'", CNET.com.au, 2006-10-11. Retrieved on 2006-11-29.
10. ^ Laser TV: The Next Gen Screen?. Red Herring (2006-10-10). Retrieved on 2007-01-04.
11. ^ "Laser TV 'no plasma killer'", Sydney Morning Herald, 2006-10-19. Retrieved on 2006-10-23.
12. ^ "NOVALUX TO DEMONSTRATE HIGH-DEFINITION LASER TV DURING SOCIETY FOR INFORMATION DISPLAY 2006", 2006-05-25. Retrieved on 2007-01-29.
13. ^ "Novalux to Demo Laser-Based HDTVs at CES", PC Magazine, 2007-01-04. Retrieved on 2007-01-29.
14. ^ "Info and news about Laser TV", Laser tv news, 2007-01-31. Retrieved on 2007-01-31.

---

v • d • e Display Technology
Non-video	Split-flap display | Flip-dot display | Electronic paper
Video	Vacuum fluorescent display | Cathode ray tube | Plasma display (Organic) Light-emitting diode | Laser TV | Liquid crystal display Digital light processing | Liquid crystal on silicon Surface-conduction electron-emitter display | Field emission display Incandescent light bulb
3D	Stereoscopic | Volumetric | Laser beam
Static media	Movie projector | Slide projector | Hologram | Neon sign