negative voltage for tft transistor

Thread Starter

leoss

Joined Jan 17, 2012
14
Could you please explain me what mean negative voltage in lcd terminology? Because I read that tft transistor is switched OFF by negative voltage (-6V). But what is difference between possitive and negative voltage in this case?

Thanks
 

praondevou

Joined Jul 9, 2011
2,942
Could you please explain me what mean negative voltage in lcd terminology? Because I read that tft transistor is switched OFF by negative voltage (-6V). But what is difference between possitive and negative voltage in this case?

Thanks
Please post your source. Where did you read it?
 

praondevou

Joined Jul 9, 2011
2,942
http://www.personal.kent.edu/~mgu/LCD/tft.htm - here I read about negative voltage which swich OFF tft transistor

-but I couldnt find article, where I found that it is -6V

In the first post you say that you found an article stating that the TFT is being switched of with -6V. In your most recent post you say you can't find an article with this information.. :confused:

These transistors are much like MOSFETs, for an n-channel transistor a positive voltage is being applied to the gate (with respect to the source), for a p-channel it's a negative voltage (also with respect to the source).
 

Thread Starter

leoss

Joined Jan 17, 2012
14
Sorry, but in first article I wrote, that I read it, but I see many articles per day and I cannot remeber on it. And this is clear for me, but I dont know what mean negative voltage in tft terminology. I read that in lcd is Vcom like ground and Vcom has about 7,5V. So this -6V is what? Is it minus because Vcom is 7,5V and it is under or because it is on another side of source?
Thanks
 

praondevou

Joined Jul 9, 2011
2,942
Sorry, but in first article I wrote, that I read it, but I see many articles per day and I cannot remeber on it. And this is clear for me, but I dont know what mean negative voltage in tft terminology. I read that in lcd is Vcom like ground and Vcom has about 7,5V. So this -6V is what? Is it minus because Vcom is 7,5V and it is under or because it is on another side of source?
Thanks
Well then it would be very helpful if you find the article talking about -6V again and post a link here. ;)
 

Thread Starter

leoss

Joined Jan 17, 2012
14
It is possible, that this tft transistor is turned off by 6V voltage? Because I think, that it is negative, just due to Vcom is reference ground and it is around 7V.
 
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