Innolux BT156GW01 TFT LCD Panel teardown

[reagle]

Going through of pile of stuff I've wanted to take apart for a while, so here is another one located at http://kuzyatech.com/innolux-bt156gw01-tft-lcd-panel-teardown


This is a panel used in many laptops, including Dells. I've not been able to locate datasheets for some of the chips used, so hoping somebody can weigh in on a few things:
 What does the main LVDS chip do on this thing? I see 4 LVDS lanes coming in and 7 coming out. They seem to be separating clock and video data and then sending that to the six individual driver chips mounted on the flex cables.  Do they do some processing there as well?

The other question is why do they leave extended data EEPROM power pin connected to the main connector instead of powering locally?




And finally, I've counted 6 separate optical films behind the display (and none in front)

Some are pretty obvious, like the rear reflector and backlight sheet. But then I see two diffuser like sheets and two Fresnel-like or prismatic sheets. What do they do?

[mikeselectricstuff]

The funky optical stuff is to make the light source more directional, concentrating it in a more forward direction through the panel - light passing through the panel at an angle is mostly wasted.
demonstration here starts 27:50:
https://www.youtube.com/watch?list=UUcs0ZkP_as4PpHDhFcmCHyA&v=gScwGhRSQFI&feature=player_detailpage#t=1664s

[amyk]

The main chip is the TCON, or timing controller. It takes the main LVDS input and generates the appropriate row and column drive signals. The 4 lanes are 3 data and 1 clock. The output is one for each stripe (683 subpixels each) and another for the row driver. There is no processing of the signal beyond clocking it into the drivers, which translate it to the appropriate drive levels from the bias voltages.

It's hard to find Novatek datasheets in general, but a bit of poking around the usual Chinese sites gave a hit this time for the backlight controller. No luck with the TCON though.

Power for the EDID EEPROM is separate so that it can be programmed at the factory independently of having to power up the panel.

The 8333 is this.

Also attached the datasheet for an older version of the panel, if anyone is interested.

[reagle]

Thanks for the answers- make the picture in my mind a bit clearer on how these things are built!
 I've added links to the datasheets and this discussion to my teardown. Shame on me for not recognizing Seiko chips though- the 8xxx  part number is very typical for them!
 Now, with all the fancy optical films I got from a rather larger panel like this, question is what can we make out of them?
I could for example make a silly LED backlit house number that's 15" in diagonal and seen from space...

[onlooker]

This is what I did from my broken laptop LCD: adding backlight to hp3457a. There are still planty materials left.

The light source was made from "Car Vehicle 16 SMD LED Light Bulb" (ebay, 2 for $1.95). Each bulb can be cut into 4 strips and one strip was used for each  3457a.

[reagle]

Not a bad idea! Maybe I'll do that to my BP precision power supply - the EL backlight is barely visible there..

[PTR_1275]

Onlooker, do you have any more information or photos of the mod you did to your 3457?

Did you just put the led strips in there, or did you need to put a film on the front of the display too?

I'm very interested to do this for my 3457 and 3478 meters as it is bloody hard to see them across from my other bench.

[reagle]

Me too! I have a 3478 that's annoyingly hard to read and also Keithley 197 that could use that

[tooki]

This is what I did from my broken laptop LCD: adding backlight to hp3457a. There are still planty materials left.

The light source was made from "Car Vehicle 16 SMD LED Light Bulb" (ebay, 2 for $1.95). Each bulb can be cut into 4 strips and one strip was used for each  3457a.

Do you have any photos of the internal construction of your backlight mod? Cuz that's precisely what I wanna do to my Keithley 197.

[tooki]

Look at the date of the original post.

[onlooker]

I just read reagle's message and the new posts here. The details are in,


https://www.eevblog.com/forum/projects/hp-3457a-lcd-backlight-mod-(also-for-3478a)/

[reagle]

Awesome, thanks for linking. I did search for it but could not find