HD Picture is slightly blurred

SOURCE: Sharp LC-37D4U 1080i picture problem

have the cable company set the box to 720p whic is the native resolution of the set.this will help with quick signal adjustment

SOURCE: 52D82U Fuzzy picture

Change your input source. You are probably on Input Source "TV". My HDMI cable is plugged in INPUT 4 so make sure that your TV is set to the right INPUT.

SOURCE: Sharp Aquos LC-65D64U Picture Quality

You need to change your TV's settings and enhancements. Directly from the store and out of the box, the settings are adjusted for easiest sell in the store. That means that:
Your contrast is cranked to 100. Move this down to 50 to 60.
Your brightness may also be cranked up high. Lower it to a level nearer the middle range but not so dark as to lose detail in the shadows.
Your TV is set on "Dynamic" or "Vivid" mode. Pick "natural" or "normal" or standard.
Your sharpness is at least on, if not cranked up. Turn sharpness down or off, and the same with "Edge Enhancement" and "VSM", all to off.

Lastly, I bet you upgraded size and you are now sitting too close to the TV. Roughly, if you are sitting closer than 130 inches (about 11 foot) you might do some rearranging or save some money and get a smaller TV.

SOURCE: SHARP aquos 1080p HDTV: VCR image flickers when playback

I have the same model TV and the following worked for me. I am using A/V cables attached to Input1 on back of the TV.

On your Sharp TV remote control:
1. Select the Input (1-5) that is attached to your VCR.
2. Go to the menu and select options.
3. Change your color system to NTSC.

This should stop your picture frome flashing on and off.

You still may have a issue with the screen colors. I don't know of a way to address this, other than to make the picture monochrome.

Hope this helps.

SOURCE: Close captioning on HDMI

The TV will not display closed caption with HDMI input. It must either over-the-air (antenna) or composite input for the TV to manage CC.

To get CC with HDMI from your Comcast DVR, you need to configure the cable box. Instructions can be found here:
http://en.wikibooks.org/wiki/How_to_use_a_Motorola_DVR/Setup

If you want CC all of the time, this works well. But since you must power-off the cable box to change the setting, switching CC on and off is a real pain.

Your set-up is similar to mine (Sharp Aquos 46" and Comcast DVR). I have the composite output from the cable box going to a DVD-recorder and on to the TV. Whenever I need CC (usually to catch some mumbled dialog), I just rewind the DVR, and switch the TV input to the composite input. Then I switch back to HDMI to continue watching in HD.