SHARP AQUOS 46INCH CANT GET A FULL PICTURE ONLY IF I USE ZOOM WILL THE SCREENBE FULL
You're describing what is called letterbox and pillerbox. Letterboxing is when there are two horizontal bars - one at the top and one at the bottom of the screen with a wide picture between. Pillerbox is when there are two vertical bars - one on the left edge and one on the right edge of the screen with a tall picture between.
The settings on your TV (and on your cable box, satellite box, DVD player, etc.) tell the TV how to display a picture that will not fill the screen completely. If the program source (an older video-taped TV show, non-widescreen version DVD, etc) was not originally "shot" or saved in widescreen format, the TV offers you a choice on how to display the image. They ask if they should stretch or zoom to fill the screen (and you have to deal with the skinny / tall images or lost portions of the picture); or maintain the aspect ratio (not stretching or zooming) by leaving a part of the screen blank (grey or black) by inserting bars left and right or top and bottom of the screen.
Start out by telling the devices that send pictures in a format that matches you TV's screen ratio. I am assuming you've got a wide screen HDTV which would mean it should be set to "16 x 9" (a.k.a. 16:9) ratio display. If you have it set for 4 x 3 (a.k.a. 4:3) you should change it. Look for a setting on your TV that asks about stretching, zooming, etc. as this will be an issue when receiving picture from an off air antenna on your house when a TV station is airing an older, non-wide screen format TV show or movie.
TV signals provided by Cable TV or Satellite provider must be HDTV type signals. If you have the standard TV service (non-HD) no picture sent by them will ever fill the screen. This is because Standard Definition TV (SDTV) is not capable of those types of signals. You will have to bump up your subscription to HDTV service to get full screen pictures.
I hope this helps!