ကိုကြီးဇော် ( မုန်တိုင်း )

Many people have recently started to ask how to connect an LCD screen taken from an old laptop computer. This is a very common question in many discussion forums. The common answer is NO.

Circuit diagram Laptop LCD Display to VGA Interface Project

The LCD is generally driven by a custom chip set and for many laptops, the interface requirements are very different than in VGA interface. Generally the needed conversion is a difficult and expensive task. This is not a task for a novice, and many professionals will also not bother.

Circuit diagram Laptop LCD Display to VGA

Circuit diagram Laptop LCD Display to VGA Maxim

Circuit diagram Laptop LCD Display to VGA display

The real answer is: IF the screen can directly accept a VGA input signal (which the majority of LCD screen used in laptops don't accept). If the display has a VGA input, or some other analogue RGB input, you can propably get VGA signal wired to that display in some way and propably picture with some cating. Otherwise you're much better off just buying a ready made LCD monitor.

If the display does not have analogue RGB inputs (like practically all LCD screens in laptops use), there is no simple solution for this conversion because the differences of the interfaces used in normal VGA monitor connections and the interfaces used in laptop LCD screen. The LCD screen on laptops typically use a special digital inteface between the graphics controller and LCD screen itself. Those interfaces can be special high speed parallel or serial interaces and there are many flavour of them in use. The graphics cards inside the laptops have that special interface compatible with the display in this laptop, but normal PC graphics cards do not have this kind of interfaces. One problem is also that there is wide variety of LCD display interfaces in use, so first you need to figure out what interface is used (can get hard) and then get somewhere information how to interface to it (information might not be publically available). Here is a list of some LCD screen interfaces used or in-use nowadays:

• Analog VGA (used in external LCD displays but not in laptops normally)
• 44-pin TTL parallel
• TTL level clock and 8 data lines interface that has signals that match with 26 pin "VGA feature connector"
• 20-pin LVDS serial
• Digital Video(6-bit for each color R/G/B) Sync Signal,DOTCLK, 4 pairs LVDS (used in some IBM laptop displays)
• DVI (Digital Visual Interface LCD panel digital interface from DDWG, used for external LCD screen mainly)

Now this is a project i always wanted to build, but never had the chance, or the mood. Its kind of complicated, so beginners should approach this project. Thats probably the reason i did not build it myself because when it first came up to me this idea i was still a beginner and did not had enough experience, and even now when i can say i have some experience i still could get into trouble with this project. The authors of this projects explains the problems that he came across and how he solved them. You should expect some pixels looking distort, the project its a work in progress and even in the final form you cant get perfect results. Unfortunately the author fried its panel until the completion of the project by accidentally switching the +12V and +5V lines. So he says it will finish the work on project as soon as he gets a new LCD panel.

Labels: Computer-V