| Electronics > Beginners |
| Why does the average digital TV set take so long to "come on"? |
| << < (5/7) > >> |
| rdl:
I paid attention the next time I turned the TV on and it actually took only about 10 seconds. The backlight came on at about 7 seconds, followed by the input selection display. The Windows desktop appeared maybe a second later. That doesn't seem too bad. I don't have any channels to switch, so I don't know about that. |
| Dave Turner:
Man, We are so impatient these days! Does anyone recall old analogue valve TV's. Not only did they take an age to warm up, but in the UK at least, there were only a couple of channels until 1964 when BBC2 commenced. Much of the entertainment was trying to decide when, on switch off, the last 'spot' on the phosphorescent screen decayed into invisibility. >:D Dave |
| IconicPCB:
You should have seen my old girlfriend... an analogue model... took for ever to "come on". |
| Bicurico:
A modern LCD TV is built with many components. And it behaves like a computer: 1) When turned on, a bootloader inside the flash is started. 2) The bootloader checks if all components are OK. 3) The bootloader then needs to move the remaining firmware from flash to memory. 4) Then the firmware starts, which is actually almost an OS - on Smart TV's. 5) The firmware needs to start tuner, MPEG2/4 engine, video processor, audio processor, surround processor, etc. 6) Meanwhile it starts showing the picture of the last set input. 7) The video/audio stream needs to be buffered and gets sent to the video/audio processors for all sorts of enhancements 8) Finally the OS has finished booting and loading all the SmartTV stuff. 9) The front processor is now ready to receive commands from the remote. 10) If the DVB-S/S2/C/T channel is witched, the MPEG decoder needs to wait for a key-frame, which can take up to one second. This is just a rough list of all that is going on inside a modern TV! Better TV's may have some advanced logic to allow fast switching on channels of the same transponder, by keeping a simultanous tack of each stream. But if you change transponder, you will have to wait again for the tuner to lock in and the key-frame to appear. Regards, Vitor |
| coppice:
--- Quote from: Bicurico on April 13, 2018, 11:02:49 pm ---A modern LCD TV is built with many components. And it behaves like a computer: --- End quote --- A modern TV is not just like a computer. It is a computer, and a perfectly good development system for its own code. In the TV development labs I've been to, people just connect a USB keyboard and mouse to a TV, and sit in from of its 65" panel developing the TV's code. |
| Navigation |
| Message Index |
| Next page |
| Previous page |