why do the lasers not shutoff after a certain time in DVD players

[BirdDad]

The players were left on the root menu and burned in.
shouldn't there be an automatic shutoff after a time?What about the blu-ray/hd DVD players do they have this feature?

 

[A5]

Most DVD players will hold your position in the movie as long as you don't change discs...use the Stop button on the remote.

 

[BirdDad]

that really doesn't answer the question

 

[vshah]

never happened to me, my dvd player has a sleep function. sleep on all my electronics that have it in the HT is set at 2 hours.

 

[sdifox]

Well, how about using the power button? I mean, either you learn to turn it off or put up with buying more dvd players.

 

[jtvang125]

I don't see why it's so hard to turn it off. I've left mine on overnight a few times but a few days? And almost all dvd players today have a remote so you don't even have to get up to turn it off.

 

[BirdDad]

we leave it on because we forget about it being in there
why is there no autoshutoff?

 

[darkswordsman17]

Originally posted by: BirdDad
we leave it on because we forget about it being in there
why is there no autoshutoff?

A lot of them do have auto-standby features. You might check to see if yours does and its just disabled.

 

[BirdDad]

I am sure that on a few of them the disc was just left on overnight but still burned in the optical pickups

 

[spacejamz]

I can understand losing two (maybe three) players for the same reason, but five?

Did you not learn your lesson after the first two went bad????

 

[Modelworks]

I'm not sure what your complaint is here .
Are you saying the players burned out the laser ?
That is very very unlikely, especially in 5 different players.

I'm a engineer that used to design the firmware in these and other consumer products.
I can tell you the life span on a laser diode in a dvd/cd player is about 10 years.
Thats 10 years of continuous operation.

Also every player I ever worked on was designed to stop spinning the disc and turn off the diode after 15 minutes max. The player would simply record the information for where it was paused and then resume if need be. This was done to save wear on the pickup not so much the spindle or the laser.

When the player is in pause the laser is not actually sitting there on full power reading the same exact spot. It goes into standby mode and waits for the command to read the next pit. The same with the disc on stop. The laser switches on usually within 5ms so theres no need to remain on all the time when data isn't needed from the disc.


The pickup assemblies do go bad, but 5 players in a row ?
Very unlikely.

 

[BirdDad]

Also every player I ever worked on was designed to stop spinning the disc and turn off the diode after 15 minutes max. The player would simply record the information for where it was paused and then resume if need be. This was done to save wear on the pickup not so much the spindle or the laser.
This is exactly what I am talking about how come I get the ones that don't have this?

 

[Modelworks]

What brands are you buying ?
I dont know of any brands that do not spin down.

When I said save wear on the pickup I did not mean to keep it from being "burned"
The pickup is a mechanical device with lots of tiny moving connection,
It has to constantly adjust angle, distance, filtering in order to keep the beam bouncing off the disc as readable. Its just better design to let them rest when not needed.

Mechanical failure of the pickup is much more likely than a "burn in" type situation.
But 5 players that have failed pickups , thats extreme.
To burn the actual sensor you would need to increase the output power of the diode above what the sensor is rated. Otherwise you could leave it there for weeks, the sensor isn't going to change.

 

[BirdDad]

Apex,Philips, and Toshiba

 

[BirdDad]

whatever is hapening the devices do not cut themselves off if left on the root menu

 

[Gunslinger08]

I don't even understand what you're saying went wrong with them. "Burned in"? How does a DVD player burn in?

 

[BirdDad]

I'm just guessing thats whats happening that the laser is constantly on and burns in the optical pickup
regular CDs still work fine on these machines but DVD dosen't

 

[nullpointerus]

After you lose the tenth, I'd say it's about time to call or read manuals before purchasing.

As to your original question, the reason for these failures is simply poor product design and testing.

FYI, in our family, someone is designated "the guy responsible for turning off HT stuff when not in use"--mostly because I'm the only one who cares (and/or knows what to turn off ). You may want to consider a similar "system" to prevent future problems.

 

[RaiderJ]

Well, with DVD players $30 or less, just keep buying new ones! With five players down for the same exact reason, I doesn't seem like the cause of the problem is going away anytime soon.

 

[onlyCOpunk]

You could set a timer on the power point and set it tun off at a certain time at night if making sure the dvd player turned off is too difficult to do