my lcd heats up

[muchix]

hello everyone, i have just finished to connect my 4x20 lcd lpt display. i managed it to work fine with lcd smartie , just my concenr is that the lcd display generates too much heat. i dont know if thats normal but after 10 minutes of being @on@ i can barely touch it with my hands.
any ideas? is that normal?
hmmm i connected the backlight directly to 5v and ground in my computer molex. and the 3rd pin of my display, corresponding to the contrast, i jumped the potenciometer,or variable resistor, and i just connected it to ground.
perhaps the fact that i have ommited some resistors in the previous named pins could affect the temperature?
i aprecciate any comment.
Thanks a lot

[mattcro]

Is the backlight very bright? if it is, you might be putting too much current into it. Some LCD modules have resistors built in to allow direct connection to 5V for the backlight. On some modules you must add a resistor in series with the backlight for operation from 5V. Check your datasheet if you have one. The LCD should not get very hot - maybe a bit warm.

If the LCD contrast looks OK (you can read the display fine) then it's quite safe to have pin 3 (contrast) connected to ground.

[muchix]

Thanks a lot for ur help. yes indeed it was the fact that i connected directly to 5v for the backlight. i used a 100k potenciometer and now i reduced the bright and the lcd wont heat up.
for the contrast yes i have it directly to ground and i can read all perfect. so its ok to leave it like that.