Getting these higher resolution files to home televisions is no small matter. A Blu-ray disc format has not been created yet and broadcasters are years away from offering TV signals at the higher resolution.
Sony representatives said that buyers of its 55-inch and 65-inch TVs may be asked to buy an ultra-HD server separately, although a final decision hadn't been made. It is also unclear how much downloadable movies will cost.
The company said it would offer Blu-ray discs that are mastered in 4K but compressed to fit on a current Blu-ray disc. The TV's embedded technology presents the compressed movie at close to 4K resolution, but not quite as good as when they are played from the 4K media player.
But with all new technologies, there were glitches.
Hirai had an embarrassing moment Monday when he introduced the world's first ultra-HD TV using organic light-emitting diodes (OLED), only to see the screen go blank as the computer running it had an error.
"This revolutionary TV combines the world's largest OLED display with dazzling 4K resolution, including this beautiful ... interface screen," he said, then turned to see a blank screen as chuckles rippled through the crowd.
Later, Hirai looked back at the 56-inch display only to see the error continue.
"Excellent," he said.
A Sony staffer rolled the TV further away and Hirai carried on his presentation. He later appeared to be good-natured with journalists.
Hirai said the ultra-HD OLED set is a prototype and didn't announce price or availability.
In the Sony booth after the presentation, other ultra-HD OLED screens played without a problem.