Cold CRT Guns for Thinner CRTs

Fly writes: "According to EETimes, an Austin startup company is close to producing CRTs with cold-emission electron guns. They claim this will reduce the parts needed for electron guns as well as allow for greater control and deflection of the electron beams leading to thinner CRTs. Their technology uses older chip-manufacturing techniquest to deposit diamond tips for the guns on silicon wafers. They hope to enter the CRT market next year."

Comments

CRT has its merits over LCD

[tepes]

CRT emits light, doesn't have to worry about latency and visual memory causing ghosting (a problem, I've heard, with TFT and OLED). CRTs also handle colors better. Some of the comparisons and an overview of LCD technology are at ZDNet and ErgoDynamix

Re:CRT are on thier way out

[Anonymous Coward]

Viewsonic VP230mb

ViewSonic proudly introduces the 23.1" VP230mb LCD display with 170 viewing angles and a 1600 x 1200 native resolution

As for some new cars: here's a good place to start :)

Heater isn't the big power waster.

[Ungrounded Lightning]

hot CRTs waste energy ... they don't require any actual heating for operation, and I doubt (though I don't know) that they'll even get warm in operation.

The CRT's heater wastes some energy. But most of the energy consumed in a monitor is the energy dumped when the magnetic deflection field "flys back" at the end of each horizontal scan line. Some of this is recycled - into the accelleration high-voltage supply or even powering the CRT's heater - but most is just dumped as waste heat.

This is just a replacement electron gun, so it won't do anything about the deflection power waste. But see my other posting and its parent here.

Ghosting was recently solved.

[Ungrounded Lightning]

The only flatpanel displays that look as good as a CRT to me are extreamly expensive. All the ones that are of lower cost have that wacky ghosting effect, not as bad as the old dual scan LCD displays, but it's there when playing higher framerate games..

That was recently solved - by remembering the previous frame and computing a voltage that would rapidly force the liquid crystal to the correct transparency rather than feeding it the voltage that would eventuall lead to it stabilizing at the desired transparency and letting it relax to that transparency in its own sweet time. There was an article about it maybe a month ago in slashdot.

Exepct TV-rate LCDs without ghosts as soon as this gets incorporated into the driver electronics - assuming the patent holders don't sit on it.

Re:almost makes flat screen technology easier

[sjames]

This won't have much effect on the face of the tube. It still has to have the same surface area acted on by the external air pressure.

However, since the cold emission guns can work at greater deflection, the tube can be shorter, so the sides of the tube benefit from a reduced surface area and a shorter span..

The gun itself should be smaller since it won't need a bulky heater.

A big benefit comes from not having to power the heaters. While still requiring more energy than LCD displays, it's an improvement.

Given the less complex assembly (15 rather than 35 parts), reduced materials cost, and simplified and smaller power supply, it may be possable to produce monitors based on this technology for about the price of a conventional CRT (once retooling costs are covered).

Since this CRT will have some of the advantages of LCD (only to a lesser degree) over conventional CRT, it will apply more competitive pressure to LCD and the not yet here LED display developers.

Even if vastly improved and cheap LCD and LED screens come out tomorrow (hah!), the company will be OK. The cold emission technology still has applications for devices in high radiation environments AND military hardware than must withstand EMP. It might even shift the balance back to tubes (from power transistors) in some high power applications.

The technology formerly known as microtip displays

[SysKoll]

SET MODE=OLD FART

Reading this article made me jump way back in time. At that time, I worked in a Big Company located in the same campus as PixTech, a startup that had a deal with Japanese display specialist Futaba to produce microtip displays in a European lab in Montpellier, France. Pixtech produced a monochrome prototype, then the price of LCD collapsed and the funding dried up. That was in 1993 or 94 if I remember correctly.

PixTech wanted to create a technology and then licence it to mass producers. They entered an agreement with Texas Instrument, but after LCDs started to be dirt cheap, the agreement collapsed.

The principle in these screens seems to be the same as the technology explained in the article. Behind each phosphorus dot (1/3 pixel roughly), a few dozens to a few hundreds cold cathode cones emit electrons and replace electron guns. The European technology was using silicon tips instead of diamond, but the principle stays the same: In an electrical field, a tip tends to concentrate charges, hence a cone easily releases electrons when negatively charged.

The beauty of the scheme is that even if the yield of the microtip fabrication is not perfect, you don't care because there are many of them behind each phophorus dot. Compare and contrast with LCD screens, where a single defective transistor will leave a permanent dead pixel.

I am a strong supporter of this technology, because it allies the advantages of CRTs with the flatness of LCDs. But I have seen several startups fail while trying to market microtip screens, so I am wondering if it's not jinxed or something...

-- SysKoll