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Nanotube Field Emitters Beat OLEDs

10/16/2014 09:00 PM EDT
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J---
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Re: Efficiency
J---   11/23/2014 10:07:58 PM
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I had to check the date on the article to make sure I was not looking at an old article. Production LEDs are hitting almost 200 lumens/watt at lower drive levels and even OLED is pushing 100. Unless you are at that level its a non starter unless you are providing a unique feature and I am not seeing that here. There are lots of "maybe" techs but until you can compete even closely to the low cost state of the art in current tech, then it is just potential.

J---
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Re: Efficiency
J---   11/23/2014 10:07:53 PM
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I had to check the date on the article to make sure I was not looking at an old article. Production LEDs are hitting almost 200 lumens/watt at lower drive levels and even OLED is pushing 100. Unless you are at that level its a non starter unless you are providing a unique feature and I am not seeing that here. There are lots of "maybe" techs but until you can compete even closely to the low cost state of the art in current tech, then it is just potential.

GSKrasle
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Re: Efficiency
GSKrasle   10/23/2014 8:38:27 PM
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From Wikipedia, "A source radiating a power of one watt of light in the color for which the eye is most efficient (a wavelength of 555 nm, in the green region of the optical spectrum) has luminous flux of 683 lumens. So a lumen represents at least 1/683 watts of visible light power, depending on the spectral distribution." The max POSSIBLE efficiency is 683lm/W. The hughest I see listed for a white LED is 150lm/W ( and I see a theoretical max of 260-300), and Sodium lamps are listed at up to 200lm/W.

R_Colin_Johnson
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Re: Efficiency
R_Colin_Johnson   10/22/2014 12:45:02 PM
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@lem1 I sent your question to the researcher and here is his response: All lighting devices including our device and LED etc. have a limit of brightness efficiency, and cannot overcome more than around 640 lm/W. We found that a new panel with line electrodes patterned based on our prototype simple diode device mentioned in RSI could obtain higher bright intensity by the optimization of afterglow of phosphors and control of line sequential scanning condition. We think the phenomena comes from the spatial Broca-Sulzer effect based on visual effect. (However, I am sorry that we cannot tell the detail information of pattern design in a new panel and sequential condition for the strategy of our patents.) Our manuscript in RSI introduces about our simple diode panel as a breakthrough element to construct a new panel with low power consumption. When our simple diode device can get the brightness efficiency around 70-80 lm/W, we think that a new panel based on our simple diode device can have low power consumption under 0.1W.

R_Colin_Johnson
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Re: Efficiency
R_Colin_Johnson   10/22/2014 12:45:00 PM
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@lem1 I sent your question to the researcher and here is his response: All lighting devices including our device and LED etc. have a limit of brightness efficiency, and cannot overcome more than around 640 lm/W. We found that a new panel with line electrodes patterned based on our prototype simple diode device mentioned in RSI could obtain higher bright intensity by the optimization of afterglow of phosphors and control of line sequential scanning condition. We think the phenomena comes from the spatial Broca-Sulzer effect based on visual effect. (However, I am sorry that we cannot tell the detail information of pattern design in a new panel and sequential condition for the strategy of our patents.) Our manuscript in RSI introduces about our simple diode panel as a breakthrough element to construct a new panel with low power consumption. When our simple diode device can get the brightness efficiency around 70-80 lm/W, we think that a new panel based on our simple diode device can have low power consumption under 0.1W.

DrFPGA
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Re: So, does the Phosphor Age
DrFPGA   10/20/2014 1:45:17 PM
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Thanx for the follow-up. Excellent reporting! Keep up the good work.

R_Colin_Johnson
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Re: So, does the Phosphor Age
R_Colin_Johnson   10/20/2014 1:29:18 PM
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Here are Dr. Shimoi's answers to your questions:

>1-What is the energy efficiency of your prototype now and what do you expect it to be in the future after optimization?



The energy efficiency of our present prototype is around 50 to 60 %. We think the loss energy may be Joule heat loss by impacting electrons to phosphors. We will expect it will be close to LED's brightness efficiency after more optimizations.

 

>2-How long will the phosphors last? Will they affect lifetime? And will they get dimmer over time?



The present life time of the phosphors is around 1000h now until reaching to a half of initial output brightness. The phosphors will get dimmer over lifetime. We have to optimize or develop a new phosphor for employing as a consumer lighting device.

 

>3-What colors will be available? Just cool-white and warm-white or do you have other colors >planned?



White including cool and warm-white, the primary colors (RGB) are available. If we will succeed to establish a plannar lighting device, we will try to construct a color television or monitor in the near future.

CC VanDorne
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Re: Better valves?
CC VanDorne   10/20/2014 10:23:47 AM
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@ChristophZ  Technically, I can't see why not.  I've taken to studying these old beasts lately and the focus of the challenge with making valves/tubes (and their eventual down-fall) always seems to have been cathode efficiency & reliability.  Solve that with this new technology and you might be on to something.  From the article, "1000 times" efficiency jumped out at me right away.  Economically, it's a different story.  A thorough study the viability of the audio market would be needed.  (There are no bigger snobs than audiofiles, but the guitar-player market might be on board.)  Weigh that against the cost of spinning up your new "cold-cathode" audio-valve plant.

But two notes on that: 1) Avoid using the word "cold" in any marketing campaign, unless it's for medicine.  ("My guitar licks are HOT! and so is my amp." See?)  Anyway, I suggest "Cool-Cathode" Valves.  ("My guitar licks are cool, bother.  So am I and so is my amp."), or "warm" might work too; 2) You'll need to substitute in the "tubes" for "valves" for US marketing.

ChristophZ
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Better valves?
ChristophZ   10/20/2014 7:28:41 AM
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Can we use this technology to build power efficient successors of the old valves (triode, pentode and such) still used in audio equipment?


All the heat they procudes and nearly all aging effects are comming from the heating needed to emit electrons.

lem1
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Efficiency
lem1   10/18/2014 4:02:29 PM
The article mentions a couple of numbers:

- 1/100th the power of LED

- 60lm/W for this nanotube field emitter vs. 40lm/W for OLED.

 

As LEDs have passed 100lm/W I would expect this device to be 10.000 lm/W. What am I not getting here?

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