IR sensor lens (filter) material.

[62caddy]

My LED TV causes the infra red sensor on older audio gear to go haywire for the first several minutes after the TV screen is switched on. Also, when the picture is dark for several minutes (such as a nighttime scene), the condition will recur even after the situation had cleared up initially.

It was suggested that an additional IR lens may help bring the interference under control but I have no idea how to go about getting the clear burgundy plastic material for the purpose. I've done many searches but have been unable to come up with anything suitable.

Any suggestions?

 

[nj pheonix]

Interesting

 

[JediDude]

Are you planning on still using the remote(s) for the audio gear? If not, a piece of aluminum foil taped over the IR sensor might block enough incoming to fix this?
.
.
.
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Waiting for RSA comments about tinfoil hats..
(I couldn't resist)

 

[62caddy]

Are you planning on still using the remote(s) for the audio gear?

That is the entire point. Could easily block the sensor using any number of means but that would not help.

*The unit is a remote preamp unit used to control the volume, some input switching and main power switching for the rest of the system.

 

[teal'c]

I've heard of this but never experienced it.

Got an old pair of sunglasses laying around? That would be my first try. Polarized if you've got some.
Quick, easy, and free.

 

[62caddy]

Usually there's some curvature in lenses used in eye wear. Need something that will lay flush over the sensor. Might be able to harvest a red clear lens from an old dead remote but I haven't seen any that would work here.

 

[audiotemp]

http://www.eplastics.com/Plexiglass_Acrylic_Sheet_Infrared_Transmitting

Just info, not a recommendation. Possibly they would send you a small sample for free, though.

 

[audiotemp]

Here are some other things you might try (if you have not already).

If light from your TV can travel directly to the sensor (i.e., with no reflections), then you might try using a screen (anything opaque) to block that path (without blocking the path from where you sit). This would decrease the overall sensitivity to light from the TV.

Your comment about the problem recurring after a period of darkness suggests that the IR receiver is dynamically adjusting its sensitivity based on the amount of light it has been seeing recently. If you were to point a small light (or even a nearby LED, maybe) at the sensor, you might keep it from seeing "darkness" and so prevent it from becoming more sensitive when that happens. (Note this may decrease sensitivity to your RC as well.)

 

[Bill Ferris]

Ok, FWIW after reading this I recalled a very similar experience to the OP`s issues, and in my case turned out to be my older 48" Sony Flat screen TV`s cold cathode back lighting warming up and radiating butt loads of scrambled noise IR into my room and blocking my IR to RF remote repeater that was located beside the TV`s screen that communicates to my living room`s A/V master source rack..
The IR pollution from the TV was so strong that it was reflecting off the rear wall and getting into the remote repeater`s IR sensor window that it over whelmed my desired remote control commands until it warmed up, though I don`t recall any problems after the TV warmed up. So until I replaced the TV I just turned it on 10 minutes before watching a DVD or Big Dish program(both in the living room rack..
And A/V installers advised me that the older cold cathode back lighted flat screen, and sometimes even plasma TV`s had caused them/their customers IR communication problems as well.
All my IR pollution disappeared when I replaced that Sony cold cathode back lighted flat screen with a 50 " Sony LED back lighted one.

Don`t know if any of this pertains, but thought to offer my experience.

BTW. If it is not known by the OP, and or other folks, anyone with a CCD camera function cell phone can locate visually the IR pollution by setting up to take a picture and totally darken the room that their investigating the IR question and just look at the phone`s screen while pointing the lense where they think the IR interference might be coming from..

Good luck with it.

Kind regards, OKB

 

[62caddy]

If light from your TV can travel directly to the sensor (i.e., with no reflections), then you might try using a screen (anything opaque) to block that path (without blocking the path from where you sit). This would decrease the overall sensitivity to light from the TV.

Won't work. The large area of the screen projects a significant amount of interference that is reflected off surfaces in the room. The screen would have to be covered with opaque material to prevent interfering with the other device.

Your comment about the problem recurring after a period of darkness suggests that the IR receiver is dynamically adjusting its sensitivity based on the amount of light it has been seeing recently.

If the picture is dark when the TV is first turned on and remains that way, the malfunction condition will not clear up after 3 minutes as it would have otherwise.

 

[62caddy]

Ok, FWIW after reading this I recalled a very similar experience to the OP`s issues, and in my case turned out to be my older 48" Sony Flat screen TV`s cold cathode back lighting warming up and radiating butt loads of scrambled noise IR into my room and blocking my IR to RF remote repeater that was located beside the TV`s screen that communicates to my living room`s A/V master source rack..

I had read about the preheating sequence on certain TV screens causing IR interference - however in this situation, when the picture remains dark (long after the TV is fully warmed), the condition will still reappear.

 

[62caddy]

If it's any help, the TV is 47" Vizio.

 

[Bill Ferris]

I had read about the preheating sequence on certain TV screens causing IR interference - however in this situation, when the picture remains dark (long after the TV is fully warmed), the condition will still reappear.

Yes. Who makes this TV and it`s age and you do know it to be LED back lighted, and have you searched on the company`s website or general web search for reported similar issues by others of the model TV.

I would love to help you Eric, but I only experienced it once as I conveyed..
It seems to me that red gel color filters used for stage lights look the same as what I`ve seen used in the red IR filters of VCRs from years ago, if that method would end up being useful for your situation..

 

[62caddy]

Yes. Who makes this TV and it`s age and you do know it to be LED back lighted, and have you searched on the company`s website or general web search for reported similar issues by others of the model TV.

I would love to help you Eric, but I only experienced it once as I conveyed..
It seems to me that red gel color filters used for stage lights look the same as what I`ve seen used in the red IR filters of VCRs from years ago, if that method would end up being useful for your situation..

47" Vizio. I got it from a friend who bought it 2011 IIRC. It's in great condition but this problem it's causing to the Mc control unit is super annoying.

The Mc has a small red LED indicator that illuminates in response to the remote's buttons being depressed. Other remotes will also cause the LED indicator to illuminate but Mc says this is normal and IR signals from other remotes are rejected (which it does). When the TV is turned first turned on, the indicator stays on steadily before growing progressively dimmer until it goes out completely - when it can be used normally.

The LED will also grow brighter/dimmer in response to the picture changing brightness during the initial 3 minute period of the TV being turned on. But whenever the TV picture goes dark for 3 minutes or so (such as a night scene in a movie or show), the LED indicator will begin to grow brighter and until the picture becomes bright again.

If the picture continues remaining dark, the LED indicator will soon become fully illuminated- whereupon the unit starts cycling the stereo on/off as if it's possessed.

 

[audiotemp]

The large area of the screen projects a significant amount of interference that is reflected off surfaces in the room.

If the light is being reflected off of many surfaces in the room, you may still achieve the desired result by sufficiently narrowing the field of view of the IR sensor. You could (for example) attach the cardboard tube from a roll of paper towels to the front of the sensor to limit its field of view to a few degrees in the direction of your RC. There are more elegant ways to accomplish this as well. Still, I understand that it may not be what you hope for.

The LED will also grow brighter/dimmer in response to the picture changing brightness during the initial 3 minute period of the TV being turned on. But whenever the TV picture goes dark for 3 minutes or so (such as a night scene in a movie or show), the LED indicator will again illuminate steadily

Are you saying that the problem recurs during the time that the TV is still dark, or that it recurs when the TV re-brightens?

 

[W9TR]

Here is a link for a really good IR PASS filter that attenuates visible light:

https://www.highpointscientific.com/zwo-850nm-ir-pass-filter-infrared-1-25inch-ir850nm1

If this doesn't fix the problem, then the set is putting out a bunch of IR and you're basically stuck.

Tom

 

[62caddy]

If the light is being reflected off of many surfaces in the room, you may still achieve the desired result by sufficiently narrowing the field of view of the IR sensor. You could (for example) attach the cardboard tube from a roll of paper towels to the front of the sensor to limit its field of view to a few degrees in the direction of your RC. There are more elegant ways to accomplish this as well. Still, I understand that it may not be what you hope for.

Are you saying that the problem recurs during the time that the TV is still dark, or that it recurs when the TV re-brightens?

Unfortunately a "tube" over the sensor will result in the remote not working because it would have to be in the direct path of the remote which is impossible from the seated position.

- Dark screen (TV on) causes the problem to recur. TV must be developing IR interference on these "dark screen" sequences. The screen saver that appears on music-only channels (no video) will also also have the same effect.

 

[62caddy]

Here is a link for a really good IR PASS filter that attenuates visible light:

https://www.highpointscientific.com/zwo-850nm-ir-pass-filter-infrared-1-25inch-ir850nm1

If this doesn't fix the problem, then the set is putting out a bunch of IR and you're basically stuck.

Tom

I might try that. Thanks.

 

[Bill Ferris]

If it's any help, the TV is 47" Vizio.

Ok Sir, here`s something that I just thought of.
Does that TV have in it`s menu a setting for tracking & automatically adjusting the contrast/TV`s back lighting based on the room`s ambient lighting via a photo cell somewhere on the bezel(frame) ?
Look at the menu settings to see, and if engaged and can be toggled off, try it and see if it has any effect.

I have no experience with Vizio TV`s, as my 35 year`s of friendship tech. friend who has been repairing TV`s for a living "doesn`t" have a high opinion of them and I`m being polite here Eric..

Don`t mean to crap in your Easter basket, but every TV brand(and he`s a warranty for most) that he`s recommended to me that my friend`s and I`ve bought are still running strong, with some daily drivers, a good ten years long in the tooth..

He has told me that even Sony isn`t what it used to be over 10 years ago, but he knows his TV`s.

 

[62caddy]

Ok Sir, here`s something that I just thought of.
Does that TV have in it`s menu a setting for tracking & automatically adjusting the contrast/TV`s back lighting based on the room`s ambient lighting via a photo cell somewhere on the bezel(frame) ?
Look at the menu settings to see, and if engaged and can be toggled off, try it and see if it has any effect.

I have no experience with Vizio TV`s, as my 35 year`s of friendship tech. friend who has been repairing TV`s for a living "doesn`t" have a high opinion of them and I`m being polite here Eric..

Don`t mean to crap in your Easter basket, but every TV brand(and he`s a warranty for most) that he`s recommended to me that my friend`s and I`ve bought are still running strong, with some daily drivers, a good ten years long in the tooth..

He has told me that even Sony isn`t what it used to be over 10 years ago, but he knows his TV`s.

NOTHING is what is used to be....

I don't think it has that feature but I'll check into it. Thanks.

What's his criticism of the Vizio anyway? (I got it used for very little money so I won't be offended.) If it ever went on the fritz, I'd just sh%$can it without thinking twice.