Pentile Screen is Directional

[640k]

Never really noticed this until today, but the Pentile screen is directional. Today I noticed that while wearing my polarized sunglasses, that the screen is much clearer in portrait than in landscape.

 

[christr]

Most LCD screens have polarizers on them. That helps cut glare down a bit. However, depending on the polarization of your sunglasses vs the polarization of the screen, you can darken it depending on how you look at it.

If you your sunglasses on while getting gas you may notice some of the displays on the pumps will go 'black' if you tilt your head.

3D IMAX works the same one. One eye is polarized one way, the other eye another. Then the image on the screen is sent via 2 lenses on the projector.. again polarized for each 'eye'. That way the left eye only sees the left image thru the lens, and the right the right. If you actually folded those glasses in half, you wouldn't see the picture on screen at all.


--chris

 

[640k]

Most LCD screens have polarizers on them. That helps cut glare down a bit. However, depending on the polarization of your sunglasses vs the polarization of the screen, you can darken it depending on how you look at it.

If you your sunglasses on while getting gas you may notice some of the displays on the pumps will go 'black' if you tilt your head.

3D IMAX works the same one. One eye is polarized one way, the other eye another. Then the image on the screen is sent via 2 lenses on the projector.. again polarized for each 'eye'. That way the left eye only sees the left image thru the lens, and the right the right. If you actually folded those glasses in half, you wouldn't see the picture on screen at all.


--chris

obviously.

i suppose i didn't provide a very clear explanation. looking at the display in portrait mode, whites look white. in landscape, the whites are droned out. what i'm seeing is not a mere effect of polarization darkening as other colors remain consistent.

if i recall correctly, phones don't typically use polarizing filters for their LCD displays as they require additional room and limit viewing angles of the display. the display needs to appear the same between portrait and landscape views as these devices are often rotated for varying purposes.

the effect that I noticed through my polarized glasses are not found on previous Motorola Droid models (any), prior to the new pentile screen thechnology. my guess is the RGBG layout of the pixels interferes with a polarized lens and is why the white seems to disappear.

PenTile matrix family - Wikipedia, the free encyclopedia

 

[JoelPollack]

For full disclosure, I am part of the team that has developed PenTile technology. I wanted to jump in here and set the record straight regarding polarization and PenTile. All modern LCD screens use the twisted nematic (TN) effect. LCD functionality is entirely dependent upon the use of polarizers as the LCD effect works using polarized light. One polarizer is needed on the input side of the TN layer to polarize the light and a 2nd polarizer is needed on the output side to “analyze” the light. Typically the axis of polarization of sunglasses is along the vertical for the purpose of blocking the glare of light reflecting off of water or from your car’s hood. Light reflected from horizontal surfaces becomes horizontally polarized so a vertically oriented polarizer acts to block that light.


LCDs typically have linear polarizers, just like your sunglasses, but the axis of polarization is generally set at 45 degrees to vertical so that in either portrait or landscape view polaroid sunglasses do not block the light. Some special applications use what are called circular polarizers to that there is no angle that a linear polarizer can be oriented to block light.


Now for the key point— PenTile technology has nothing to do with polarization or the choice of polarization. Display technology can use whatever effect is used to gate the light and it still acts with PenTile technology in the same way. It also has no effect on viewing angle, but is entirely dependent upon whatever wide viewing angle (WVA)technology is chosen for use in a given display.


The RGBG layout, referenced by 640k, is only used in PenTile OLED displays. OLEDs do not intrinsically require polarizers, but today’s OLEDs, like the one used in a Nexus One, also uses a polarizer to cut glare for enhanced viewing performance outdoors. This too is oriented at 45 degrees to the vertical and horizontal. Again, PenTile has no impact on this characteristic. For further info on PenTile please visit PenTileBlog.com.

 

[640k]

For full disclosure, I am part of the team that has developed PenTile technology. I wanted to jump in here and set the record straight regarding polarization and PenTile. All modern LCD screens use the twisted nematic (TN) effect. LCD functionality is entirely dependent upon the use of polarizers as the LCD effect works using polarized light. One polarizer is needed on the input side of the TN layer to polarize the light and a 2nd polarizer is needed on the output side to “analyze” the light. Typically the axis of polarization of sunglasses is along the vertical for the purpose of blocking the glare of light reflecting off of water or from your car’s hood. Light reflected from horizontal surfaces becomes horizontally polarized so a vertically oriented polarizer acts to block that light.


LCDs typically have linear polarizers, just like your sunglasses, but the axis of polarization is generally set at 45 degrees to vertical so that in either portrait or landscape view polaroid sunglasses do not block the light. Some special applications use what are called circular polarizers to that there is no angle that a linear polarizer can be oriented to block light.


Now for the key point— PenTile technology has nothing to do with polarization or the choice of polarization. Display technology can use whatever effect is used to gate the light and it still acts with PenTile technology in the same way. It also has no effect on viewing angle, but is entirely dependent upon whatever wide viewing angle (WVA)technology is chosen for use in a given display.


The RGBG layout, referenced by 640k, is only used in PenTile OLED displays. OLEDs do not intrinsically require polarizers, but today’s OLEDs, like the one used in a Nexus One, also uses a polarizer to cut glare for enhanced viewing performance outdoors. This too is oriented at 45 degrees to the vertical and horizontal. Again, PenTile has no impact on this characteristic. For further info on PenTile please visit PenTileBlog.com.

good info. fwiw, i have applied an anti-glare screen protector to my screen, which reduced the discoloration i was experiencing.

 

[Venom51]

Polarization in LCD's has nothing to do with glare and everything to do with controlling the lighting of the screen. When you here people talk about pixel twist they are talking about rotating the crystal to change the polarization of light so that it either passes through the filter or not. Without polarization LCD's don't function.

http://en.wikipedia.org/wiki/Liquid_crystal_display