Results 1 to 5 of 5

Thread: Contrast problem

  1. #1
    Variable Bitrate
    Join Date
    May 2001
    Location
    Thessaloniki, Greece
    Posts
    274

    Contrast problem

    I have a TFT screen that has external adjustment for color and brightness but not for contrast. I have to use it with the brightness turned all the way down in order to have good picture.
    The result is that when it's sunny I can't see it very well. The screen's back light seems to be bright enough, but I just can't take advantage of it 'cause when I turn the brightness up the picture becomes white.
    You can see that here:

    http://photos.yahoo.com/dmihgr

    Folder: LCDproblem

    I took 5 pictures with the brightness at 1/5, 2/5, 3/5, 4/5 and 5/5 to show you what happens. At the top settings it becomes really bright (you can't tell 'cause the camera I used was set to auto and was compensating with higher shutter speed for the extra light).

    So, what I wanna do is find a way to adjust the contrast.
    I opened the screen (see the pics) but didn't find a pot on the small board that the NTSC/PAL switch and the other pots for brightness and color are.
    I found two pots though, at the back of the actual screen module. One of them is marked VCO and the other H-POS. Should I mess with them?
    Could you suggest something else? Can I solder a pot for contrast somewhere?

  2. #2
    Variable Bitrate
    Join Date
    May 2001
    Location
    Thessaloniki, Greece
    Posts
    274
    If anybody knows what it takes to adjust contrast on LCDs please help!

  3. #3
    Constant Bitrate
    Join Date
    Nov 2001
    Location
    Melbourne, Australia.
    Posts
    152
    Dont know if this will help, but I had this problem with a couple of LCDs in the past. I noticed that the viewing angle had alot to do with the contrast of the screen. The higher the viewing angle was the whiter the screen got. Can you try tilting the screen backwards a little bit? Just a thought.

  4. #4
    Variable Bitrate
    Join Date
    May 2001
    Location
    Thessaloniki, Greece
    Posts
    274
    I am right in front of the screen and it's white - I move up/down, left/right to various angles and it still looks white. I turn down the brightness and it's fine from all the viewing angles!

  5. #5
    Variable Bitrate
    Join Date
    May 2001
    Location
    Thessaloniki, Greece
    Posts
    274
    Is there a chance that these AFA taiwanese people used very powerful backlights for this SHARP screen?

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •