CE Technical Forum Event : Display Technologies In Mobile Phones.

Replies

• 

  Jeffrey Arulraj

  Nice to be here for the very first tech discussion of the ELECTRONICS AND ELECTRICAL forum
  
  Now LCD displays are getting out dated due to the prime disadvantage that their angle of vision is lesser than that of other configurations used here
  
  Why so is this range of vision thing really that significant in the displays
• 

  pikachu1994

  Troll_So_Hard

  And countdown ends, so let's begin here.
  Beforee starting,I am mentioning some types of displays used in mobile phones : LCDs, AMOLED, Retina display, TFT-LCD, Super-AMOLED, NOVA, OLEDs, IPS-LCD & SUPER-LCD.
  
  
  Tagging interested CEans so we can start with,
  #-Link-Snipped-#
  #-Link-Snipped-#
  #-Link-Snipped-#
  #-Link-Snipped-#
  #-Link-Snipped-#

  Tag me also troll..
• 

  Jeffrey Arulraj

  pikachu1994

  Tag me also troll..

  You your self tagged in #-Link-Snipped-#
• 

  pikachu1994

  I think retina display is the name for lcd in apple.is it?
• 

  Abhishek Rawal

  Whoa whoa friends, Let's concentrate on technical answers rather 'tag me' thing for sake of our event.
  Please !
• 

  Abhishek Rawal

  pikachu1994

  I think retina display is the name for lcd in apple.is it?

  Yup, Retina display is the LCD developed by Apple Engineers for (ofcourse) Apple devices. The pixel density or say ppi is very high (greater than 300) that an human eye cannot identify each pixels.
  
  So, is it just high ppi or something more which makes Retina display so 'awesome' ?
• 

  Jeffrey Arulraj

  Wondering about it strikes this "Near human eye vision " is provided by OLED and RETINA display
  Is the finer nature of the pixels the prime cause for them some body clear this out
• 

  Anoop Kumar

  Troll_So_Hard

  Yup, Retina display is the LCD developed by Apple Engineers for (ofcourse) Apple devices.

  Ratina Display is marketing term by Apple.
  Although apple displays are made by #-Link-Snipped-# but it is claimed by some sites that Ratina Display is solely manufactured by Samsung.
• 

  Abhishek Rawal

  This is more of optical illusion game.
  Before we get in detail, I would like to mention some terms : ppi, dpi ,arcminute.
  
  Ppi - known as pixels per inch, this is more of 'print' term.
  Dpi - Dots per inch, this term is mainly used while referring resolutions of screen.
  
  1 degree = 60 arcminutes.
  
  It's been proved that an image below 1 arcminute is not possible to view by human eye .... So, is it totally invisible? No!
  Retina display works on very simple phenomena, you might've noticed that iPhone 4GS has greater ppi/dpi than latest macbook pro, right ?
  iPhone being mobile device it is held certain closer to eyes & pixels can be viewed ... but if pixels density is increased much, the normal 20/20 human eye cannot identify pixel (or image grainy) rather than one big bright colored dot.
  While, in Macbook as human eye is not kept as closer as iPhones , less dpi lcds are used in it.
  
  More the viewing angle, lesser the spacing between pixels are noticed.
  (a type of optical illusion we can say)
• 

  Abhishek Rawal

  ianoop

  Ratina Display is marketing term by Apple.
  Although apple displays are made by #-Link-Snipped-# but it is claimed by some sites that Ratina Display is solely manufactured by Samsung.

  Term "Retina" is registered trademark by Apple.
  Plus, Wikipedia claims that LG is manufacturer of high density LCD displays of Apple products.
• 

  Kaustubh Katdare

  Troll_So_Hard

  Plus, Wikipedia claims that LG is manufacturer of high density LCD displays of Apple products.

  Add 'SHARP' as well. Sharp was one of the bigger companies that handled the display technology manufacturing for Apple for a long time (if the sources I've read are correct). The company's not doing well financially and I'm not aware of the current status. Looks like LG's getting all the contracts from Apple.
  
  That said, I want to take the discussion forward by talking about the display technology that's making waves around - the AMOLED. I can't describe the feeling I had after noticing the display for the first time at a local Chroma store.
  
  What I'm concerned about the overall life-span of the OLED displays and whether pixel density affects it. It'd be great if someone can talk about the 'pentile' displays (I've very little knowledge of it).
  
  PS: I request a someone to volunteer to summarise the discussions so far after every ~20 posts.
• 

  [Prototype]

  Let me take you to sligt different and amazing OLED display. The term OLED stands for Organic LED. I will provide more info for organic and terms later on.
  
  Basically, these displays are flexible. Yes! You can twist them, fold them and it wont affect at all.
  
  The display capability like sharpness, color depth etc of oled are little inferior than others yet there's a major advantage attached to i which makes it ideal for embeded system and as you might have already guessed, its the power consumption. It requires significantly lesser amount of power than the other technologies available. What is the reason behind this? The reason is, OLED doesn't required power to display black color and major part of any interface in an embeded system will be black in color. So wherever there's black color, the pixels at that place is simply turned off.
• 

  Abhishek Rawal

  AMOLED (Active Matrix Organic LED) the enhanced version of OLED. Organic LEDs uses thin layer of organic polymer, when electrons are bombarded on it; the light is obtained.
  It seems similar to LEDs, then what's the difference right ?
  OLED don't require backlight which means darker the dark & brighter the bright which saves the energy when cell-phone used in dark background, resulting in improved battery life.
  
  "Pentile displays" is a part of AMOLEDs, unlike other displays, Pentile displays has RGBG pixel layout which means two Green subpixels for each R & B.
  The drawback of PS is that it may appear grainy due to highly noticeable subpixels (RGBG).
  But two greatest advantage is,
  1. Greater life span than normal AMOLEDs.
  2. Screen is bright as normal screens with almost 30% of its subpixels. (This is also reason behind grainy pictures)
  
  Many complains about Pentile displays been noticed of 'blue screen'.Can anyone explain that ?¿
• 

  Abhishek Rawal

  Also Super AMOLED plus, has better viewability than normal AMOLEDs in direct sunlight.
  What internal modification is done in it ... I have no idea ... Anyone know which is better in direct sunlight SAMOLED+ or Retina display?
• 

  vinod1993

  So, for those who do not know what an OLED and an AMOLED is, let me try explaining them.
  What is an OLED? It is a solid state semiconductor device like the ones we study.(MOSFET,JFET,IC's,LCD,LED etc.)
  OLED-It stands for Organic Light Emitting Diode.
  What is it made of?. Well, Organic polymers.
  What is it's structure?
  
  Sorry for copy pasting the pic above, just trying to facilitate better Understanding.
  How does it emit light?
  It's principle is akin to that of LED's i.e by the phenomenon of Electrophorescence.
  Then what is it's advantage over LED's or LCD's?
  It does not need the use of Backlights or Filters as in LED's and LCD's which lead to better quality.!
  Types of OLED:
  They are classified into two types namely,
  1. Active Matrix OLED(AMOLED)
  2. Passive Matrix OLED(PMOLED)
  PMOLED vs. AMOLED:
  A PMOLED is restricted to it's size and resolution and it's cheaper to make.
  An AMOLED uses active matrix TFT(Thin film transistor) and other devices which allows them to be made in large sizes.
  A PMOLED is used in MP3 displays whereas AMOLED is used in smartphones,TV's and so and so forth. AMOLED actually has excellent quality.
  The greatest challenge faced is the lifetime of the Panels made of AMOLED. It lags behind the lifetime of that of LED's or LCD's.(Blue OLED's have a lifetime of just 14000 hours which is very low and Blue OLED's are a neccessity).And water can damage OLED's. OLED's are still in research.
  An interesting application of OLED:
  OLED's are flexible and might become Cheaper in future like all other electronic devices and thus the newspaper of the future would be an OLED which refreshes with breaking news and like a regular newspaper you can fold it up and keep it in you bag. Fiction becoming reality. In the near future we can hope for newspapers like that of Harry potter's..! 😀
  References:
  Well I made a whole bunch of references to explain this the best and I mention some of my references.
  HowstuffWorks-How OLED's work by craig freudenrich Ph.D.
  About OLED's - oled-info.com
  And several others.! 😀
• 

  vinod1993

  Oh my god. I was so engrossed in reading and collecting news about them that I never saw the updates. All I've tried to explain have already been explained . Infact in a much better manner.!
• 

  vinod1993

  Troll_So_Hard

  Also Super AMOLED plus, has better viewability than normal AMOLEDs in direct sunlight.
  What internal modification is done in it .I have no idea . Anyone know which is better in direct sunlight SAMOLED+ or Retina display?

  It's pretty simple actually, just try comparing a samsung galaxy(sII or sIII ) and an iPhone. you'll know which one's the best.! 😀 😉 And I suppose Samsung is better in sunlight.! So, SAMOLED+ might be the better in my opinion.! Not sure though.
• 

  vinod1993

  The_Big_K

  What I'm concerned about the overall life-span of the OLED displays and whether pixel density affects it. It'd be great if someone can talk about the 'pentile' displays (I've very little knowledge of it).

  Yeah, the lifetime of OLED's are not very long. As mentioned above the blue pixels of OLED's has an utmost longevity of 14,000 hours(infact much below that). Google's Nexus One seems to have had a lot of problems using AMOLED and thus HTC, the maker of the nexus one switched to Super LCD displays and made a false claim that they switched due to supply constraints. Infact it's due to the deterioration of AMOLED screens. PenTile layout in AMOLED will increase the longevity of the display as the pixels are arranged in RGBG layout rather than the RGB layout. PenTile displays have a minimum longevity of 18 months.! 😀 PenTile displays has it's flaws as well. It seems that it does not give the Quality of an RGB display.
• 

  Jeffrey Arulraj

  The life time of displays are always a concern If they are not satisfactory the market of those goods are going to lopside as is the scenario with OLED's now a days
  
  But the main thing which struck me is the power consumed by the display panels
  
  In LED display panel all the three colour LED RYB has to glow with maximum intensity to represent it in the screen this causes an hike in power consumption of the LED and also there is this hazard prolonged over use of White light from the LED displays can reduce the life span of the display due to Optical Catastrophic Disorder (OCD) Here if High intensity of red light is used for a longer period of time there is a potential damage to the LED matrix and substrate
  
  Mostly this damage cannot be reversed thus removing the long life of the LED
  
  Now innovative designs using CGM is under consideration to remove this effect
• 

  Jeffrey Arulraj

  Apple may have won the case against SAMSUNG in the galaxy issue but the LCD display panels of all the APPLE models are generally made by SAMSUNG design cortex
  
  But the reality is that the Samsung displays is always the best their OLED AMOLED and stuff like that are really leading the world as the top display device available
• 

  Anoop Kumar

  How touch screen works
  How does touch screen work? | Tech Bells
• 

  Jeffrey Arulraj

  The same applies to capacitive touch screens the resistive touch screens need a stylus to complete the circuit
  
  But the capacitve screens need the potential difference caused due to your touch on the screen
• 

  [Prototype]

  jeffrey samuel

  The same applies to capacitive touch screens the resistive touch screens need a stylus to complete the circuit
  
  But the capacitve screens need the potential difference caused due to your touch on the screen

  The concept of resistive and capacitive screen is different. You dont necessarily need stylus for resistive touch. All that needed is bit pressure which will cause the upper film to come in contact with lower surface thus completing the circuit.
• 

  Anoop Kumar

  From XDA tv
  
• 

  Jeffrey Arulraj

  [Prototype]

  The concept of resistive and capacitive screen is different. You dont necessarily need stylus for resistive touch. All that needed is bit pressure which will cause the upper film to come in contact with lower surface thus completing the circuit.

  That is true in the case of resistive touch but capacitive touch fails in those conditions we need to touch with an charged body like our skin or some static charged objects to trigger it