Primary headaches. A primary headache is caused by overactivity of or problems with pain-sensitive structures in your head. A primary headache isn't a symptom of an underlying disease. Chemical activity in your brain, the nerves or blood vessels surrounding your skull, or the muscles of your head and neck (or some combination of these factors) can play a role in primary headaches.
The first flat screen TV was invented in July 1964 by a team at the University of Illinois. ... That year, LCD screens were sold in sizes up to 42 inches.
By July of 1964, the team had built the first plasma display panel with one single cell. Today's plasma televisions use millions of cells. After 1964, television broadcast companies considered developing plasma television as an alternative to televisions using cathode ray tubes.