How does the Philips basic bulb diffuser work?

poiihy

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The Philips basic bulb we all know has an amazing diffuser. It lights up very evenly, and all you see is a round globe of light, unlike other bulbs where you can see where the light is coming from.

If you shine a flashlight through it on one end and look at the diffuser on the other end, you cannot see the flashlight beam. All you see is the diffuser evenly glowing.

So, how the [email protected]#$ does this amazing alien technology work?!? :eek:oo: :confused:
 

SemiMan

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The Philips basic bulb we all know has an amazing diffuser. It lights up very evenly, and all you see is a round globe of light, unlike other bulbs where you can see where the light is coming from.

If you shine a flashlight through it on one end and look at the diffuser on the other end, you cannot see the flashlight beam. All you see is the diffuser evenly glowing.

So, how the [email protected]#$ does this amazing alien technology work?!? :eek:oo: :confused:

Pretty much distance from the light source to the diffuser coupled with a high amount of diffusion. Really little in the way of optical tricks.
 

Anders Hoveland

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The Philips basic bulb we all know has an amazing diffuser. It lights up very evenly, and all you see is a round globe of light, unlike other bulbs where you can see where the light is coming from.
I agree. I was actually going to comment on this before you posted this thread.

Yeah, most plastic-constructed light diffusers I have seen on LED bulbs have done a poor job of fully diffusing the light. These diffusors are opaque (you can't see through) but much of the light passing through still does not seem to change direction much, so the "diffused light" still tends to be very directional like LEDs it was emitted from. The frosted glass on the old incandescent bulbs generally worked much better.

The Philips basic bulb has the best plastic diffusor I have seen. Despite the LEDs all being mounted on a flat board at the base of the bulb, the light distribution is nearly entirely omnidirectional, and the light being emitted is completely even over the surface of the bulb.


So, how the [email protected]#$ does this amazing alien technology work?!?
I really do not know, but I suspect the plastic may have been formulated with silica nanoparticles.
(not really an advanced technology in the plastics industry)
 
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poiihy

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Does this mean the diffuser blocks a lot of light compared to other diffusers?
If so then you could cut the diffuser off and have a really bright and compact flood light bulb. And extremely efficient! :eek:

I wonder how many lumens it would be without the diffuser. The bulb is already very efficient... 800 lumens using only 8.5 watts. Without the diffuser it would be even more efficient! wow.
 

Anders Hoveland

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Does this mean the diffuser blocks a lot of light compared to other diffusers?
I do not think so. I doubt they would be using a diffuser that cut more than 10% into the efficiency. The bulb already has a very high efficiency, especially considering how cheap it is. I do not think the designers would have used a better diffuser cover if it blocked much more light than the regular one; their main concern would have been getting as much light out as possible while keeping down the cost.
 

SemiMan

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I do not think so. I doubt they would be using a diffuser that cut more than 10% into the efficiency. The bulb already has a very high efficiency, especially considering how cheap it is. I do not think the designers would have used a better diffuser cover if it blocked much more light than the regular one; their main concern would have been getting as much light out as possible while keeping down the cost.

That comment would come from a lack of experience. 10% is nothing for a diffuser to block especially one placed close to LEDS. That would actually be a pretty good one. Anything much better needs expensive optical surface structures.
 

SemiMan

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As a price point, LEDS operating at say 135 lumens/watt and enough lumens ... Say 1000 before the diffuser ... Would cost, say, $0.65-$0.80 for a large volume supplier ... For Philips their actual cost is even less.
 

Anders Hoveland

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My point was that the bulb is already so low cost. And achieving higher efficiency tends to cost more. I was saying the efficiency is already so high I cannot imagine that the efficiency would be that much higher without the diffuser (or at least if one had put on the type of diffuser found on other LED bulbs).

Better efficiency also allows them to use fewer LED emitters, and potentially use a less expensive power supply, and of course using less power means less aluminum needs to be used for heat sinking.
I doubt they would have wanted to use a diffuser if it blocked much more light than the regular ones. The main selling point of this bulb is that it gets the job done for a low price. I am not saying they did not design the bulb with some innovations (particularly the diffuser), but these would have been low cost innovations that did not add much trouble. For example, perhaps just using a different type of bulk thermoplastic going into the molding process.
 
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RedLED

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I have LEDs shaped like the Edison bulb we all know in all the lamps in the house, and they are great! Nice warm light exactly the same color Temp. as what we have known all our lives but, they are LED, who knows when they will burn out, it will be years and years, and years. Now, since we won't be changing them don't forget to dust them off.

Next: the yard!
 

RedLED

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I agree. I was actually going to comment on this before you posted this thread.

Yeah, most plastic-constructed light diffusers I have seen on LED bulbs have done a poor job of fully diffusing the light. These diffusors are opaque (you can't see through) but much of the light passing through still does not seem to change direction much, so the "diffused light" still tends to be very directional like LEDs it was emitted from. The frosted glass on the old incandescent bulbs generally worked much better.

The Philips basic bulb has the best plastic diffusor I have seen. Despite the LEDs all being mounted on a flat board at the base of the bulb, the light distribution is nearly entirely omnidirectional, and the light being emitted is completely even over the surface of the bulb.



I really do not know, but I suspect the plastic may have been formulated with silica nanoparticles.
(not really an advanced technology in the plastics industry)
Dude, don't you have lamp shades?
 

SemiMan

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My point was that the bulb is already so low cost. And achieving higher efficiency tends to cost more. I was saying the efficiency is already so high I cannot imagine that the efficiency would be that much higher without the diffuser (or at least if one had put on the type of diffuser found on other LED bulbs).

Better efficiency also allows them to use fewer LED emitters, and potentially use a less expensive power supply, and of course using less power means less aluminum needs to be used for heat sinking.
I doubt they would have wanted to use a diffuser if it blocked much more light than the regular ones. The main selling point of this bulb is that it gets the job done for a low price. I am not saying they did not design the bulb with some innovations (particularly the diffuser), but these would have been low cost innovations that did not add much trouble. For example, perhaps just using a different type of bulk thermoplastic going into the molding process.

First goal --- sellable bulb. Bulbs are first sources of light, hence they need to be acceptable from a lighting standpoint.

I am not following? Are you suggesting the diffuser reduces light more or less than 10%.

Looking at the bulb and light, I would lean towards 15%+. The difference in LED cost between 10% and 15% diffuser would be <$0.05 and power hit approx 0.5W.

Looking at this diffuser, I am not seeing anything unique that is obvious.
 

Anders Hoveland

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I have LEDs shaped like the Edison bulb we all know in all the lamps in the house, and they are great!
The Cree LED bulbs have really nice light diffusion, but those were covered with a frosted glass bulb. Frosted glass seems to act as a much better diffuser than most of the plastic diffuser covers.
 

SemiMan

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The Cree LED bulbs have really nice light diffusion, but those were covered with a frosted glass bulb. Frosted glass seems to act as a much better diffuser than most of the plastic diffuser covers.

Except you could see the individual LEDs reasonably well. It was efficient, but not that diffuse.
 

Anders Hoveland

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Except you could see the individual LEDs reasonably well. It was efficient, but not that diffuse.
It was diffuse in a completely different way. With lightly frosted glass, you can still see the area where the light is coming from inside the bulb, but despite this the light still feels very diffuse. With most common plastic LED diffusers, it obstructs the source of the light much more, but much of the light that does pass through is still very directional. In other words, the plastic may diffuse a greater portion of the light than the lightly frosted glass, but the glass still diffuses most of the light more. There is more glare with plastic, usually.


Lamp shades don't help much when most of the light is shining straight upwards.
That's true.
 

SemiMan

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I think the light feels diffuse because the interior source is already fairly omnidirectional. Not perfect of course, but not bad.

Most "directional" bulbs, even with diffusers, are nothing more than LEDs on a flat plate. The LEDs are maybe 120 degrees. As well, the diffuser width and the base width are the same, so there is no physical way for the light to go "backwards".
 

Anders Hoveland

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Most "directional" bulbs, even with diffusers, are nothing more than LEDs on a flat plate. The LEDs are maybe 120 degrees. As well, the diffuser width and the base width are the same, so there is no physical way for the light to go "backwards".
I tested an LED globe bulb, where the diffuser width was substantially wider than the base width, and the light was still very directional. It really depends on the diffuser. These Philips basic bulbs are not directional at all.
 

poiihy

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The LEDs I have in our lamps look and work just like the 115 year old bulb they have a 1/2 sec dwell before they light but that's it. They go all directions soft, just like what we are used to.

Many/some A-style LED lamps (particularly older/classic ones or cheap ones) are very directional even with the diffuser. An example is this lamp, the old LSG 40w equivalent LED lamp.

Newer lamps handle the diffusion well. Cree lamps have many LEDs facing 180˚ horizontally, and covered with a diffuser. The Philips basic lamps have LEDs facing upwards but with a very good diffuser.

Are you installing a spot that is focused?

I'm not installing anything.
 
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