Polarized Sunglasses in 03 4Runner

[vcoglian]

So, today I got a pair of polarized Ray-Ban sunglasses. Get in the truck and cannot see the display on the radio.... Tilt my head a few degrees to the left or right and the display is clearly readable. I assume for glare purposes Toyota used polarized plastic on the radio display (the trip computer does not).

I've got the JBL 6 disc unit. Anyone else come across this with the stock or nav units?

 

[mike_d]

all lcd's require the use of polarizers to make things displayed. i bet you that if you tilt your head 90 degrees you'll no longer be able to read the trip computer. (i'm assuming that the trip computer you speak of is lcd, i've never seen one).

 

[tkr128]

I remember reading Motor Trend, Car and Driver or one of those magazines and them having trouble with the display on a Corolla.

I have some difficulty reading mine too. I have the non-JBL single-disc.

 

[bulldog-yota]

I dont have the problem with mine. Also have Ray Bans, will check out again tomorrow.

 

[mswscco]

I remember reading Motor Trend, Car and Driver or one of those magazines and them having trouble with the display on a Corolla.

I have some difficulty reading mine too. I have the non-JBL single-disc.

Yup, hard to see the odometer in my Corolla. Funny, though, everything in the 4R is clearly visible. Have no idea why LCD displays are polarized.

 

[toybox]

All my sunglasses are polarized and it does not affect me being able to read the radio or the info screen underneath it. What does affect it, albeit very rarely, is when the sun is very intense and shining at just the right angle on the displays. Then it gets washed out. Doesn't really bother me though.

 

[mike_d]

Have no idea why LCD displays are polarized.

the way lcds work is by rotating polarized light. if you have two polarizers rotated 90 degrees, no light gets through. that's because the first polarizer only lets (say) up and down polarized light through and the second one only lets left and right polarized light through. so what happens in a lcd is that there are two polarizers rotated by 90 degrees with some liquid crystal in between. the first polarizer only lets up and down light through. and the second one only lets left and right through, so no light gets through. when you apply voltage to a liquid crystal, it's lines up in an organized way (goes from liquid to crystal) and it has a neat property that it rotates polarized light. so what happens is that the up and down polarized light that got through the first polarizer gets rotated 90 degrees and by the time it gets to the second polarizer it's now left and right light and goes through the second polarizer. so by selectively applying voltage to parts of the liquid crystal you can turn parts of the display on and off.

 

[swooopeno]

I have bolle polarized glasses, and no problems here. The only thing that is ever different while I'm driving, is the rear window of the 4R and a lot of the windows of other cars. With polarized, I can see the polarized spot (I think this is the tint within the glass itself). It makes the windows look not so nice. I'm sure I'm not alone in this though.

 

[Vortec4800]

This is why Pilots can not wear polarized glasses, makes LCDs retarded

 

[mike_d]

I have bolle polarized glasses, and no problems here. The only thing that is ever different while I'm driving, is the rear window of the 4R and a lot of the windows of other cars. With polarized, I can see the polarized spot (I think this is the tint within the glass itself). It makes the windows look not so nice. I'm sure I'm not alone in this though.

yeah, i forgot about that, i don't wear polarized glasses anymore. that is the result of the tempering process of the glass. the size and rear windows of cars are tempered so that when they shatter, they shatter into little pieces rather than large sharp pieces that will cut you. what they do is heat and cool the glass very quickly. the rate of heating and cooling is different whether the glass is in air or being held onto by the machine. so during the tempering process the molecules of glass (or as close to what you can define as a molecule of glass) line up differently. some areas rotate the polarized light more than others and thats why you see a wierd pattern when you look at tempered glass with polarized lenses.

 

[RapidRunner]

Although it's fascinating how LCD's work, I personally don't have any problem reading most LCD's with my RayBan's on, including the LCD on my Delphi Roady that's installed in my 4Runner. I do have a very difficult time reading the radio and HVAC display with the polarized RayBan's on. Personally, I think it's the plastic over the LCD, because the whole face of the plastic looks almost black. It's not like I can see through the plastic and the underlying LCD is hard to read.

 

[hellothere]

glasses and LCD displays vary

Glasses can vary in their polarization - typically either to the left or the right, as the idea is to stop all reflected glare - that being glare that is in a horizontal plane (like reflected off a lake or windshield in front of you). Since orientation to the left or right can stop this horizontal glare, it does not matter for glasses.

For instruments, it is important to orient the LCD so that it is not replicating horizontal glare. Makers of aviation instruments learned this quite a while ago, and so pilots have no problem using polarized glasses today (I am a pilot, and I fly with polarized glasses). Garmin GPS units also seem to have learned this - perhaps because they are involved in aviation as well. Toyota apparently has either not discovered this with their instruments or simply does not care. It is not really a safety issue for an AC instrument to be blacked out with polarized glasses - it is just poor design.

So there is likely variation in the orientation of Toyota displays, there is definitely variation among brands of sunglasses, and that is why some can see just find while others see black displays.

 

[vcoglian]

My glasses and the radio seem to be 90 degrees out of phase. That screen is black. The odometer display is a little dark, but not an issue. Oddly though, no matter what way I turn my glasses, the trip computer does not black out. Wonder if they use a different type of backlighting on that display.

 

[mike_d]

My glasses and the radio seem to be 90 degrees out of phase. That screen is black. The odometer display is a little dark, but not an issue. Oddly though, no matter what way I turn my glasses, the trip computer does not black out. Wonder if they use a different type of backlighting on that display.

that's interesting. i wonder if after the second polarizer they put a diffuser to mix up the polarization again (or a quarter-wave plate to make it circularly polarized). i heard rumors about them doing this for airplanes becaue pilots like polarized sunglasses. maybe toyota is doing it too.

 

[mswscco]

Re: glasses and LCD displays vary

Glasses can vary in their polarization - typically either to the left or the right, as the idea is to stop all reflected glare - that being glare that is in a horizontal plane (like reflected off a lake or windshield in front of you). Since orientation to the left or right can stop this horizontal glare, it does not matter for glasses...

All retail polarized specs are made to block out vertically polarized light, determined simply by the orientation of the lens within the frame. So depending on quality control the lenses may be off by a few degrees, but should not vary too much. This leads me to believe that the difference is more in the LCD displays than in the glasses, especially since I have no problems reading displays in the 4runner but visibility in my Corolla is down 40-50%.

I've also found that head tilting doesn't affect the visibility of the 4runner displays nearly as much as it does in the Corolla, so maybe there are efforts being made to address this particular issue.