Display Blog

Display World Links

2010-12-29T13:41:00.001-08:00

* DigiTimes – Taiwanese source of best daily display industry news
* Displaybank - Korean market research firm focused on the Asian display industry
* DisplaySearch – Largest market research firm focused solely on the display industry
* Insight Media – US display market research firm with special expertise in projection
* Interlingua FPD Online – Translated versions of major Japanese market research reports
* iSuppli - Market research firm focused on the entire electronics industry
* NE Asia Online - Source for daily news on the Asian electronics industry
* SID - Worldwide professional society for the display industry
* USDC – Association of US display industry companies and the US government
* Veritas et Visus - Series of five specialized display industry newsletters
* WitsView – Taiwanese market research firm focused on real-time LCD pricing

What is Brightness Contrast Sharpness and Saturation in TV exactly??

2010-12-12T22:03:00.000-08:00

A lot of people do not exactly know the difference between Contrast and Sharpness or Brightness and Saturation in TV usually. Moreover, these terms are very confusing and misleading when the display technology changes. For example brightness in LCD display is a complete different mechanism compared to a Plasma display or LED based LCD display. So let me walk you through the basics of these terms in different display systems.

Brightness in LCD is setting the "Black" level of the display. Increasing the brightness causes the black level to be greyed which causes the color channels to be washed out. While Contrast in LCD is setting the range between "Black" and "White" level of the display.

Since LCD is not a self-illuminating display system brightness in LCD is amount of light allowed from backlight. Increasing the amount of brightness causes the liquid crystal shutters to open widely causing high leakage light between adjacent pixels. So "black" level gets greyed out due to back light leaking from the liquid crystal channels. This has an adverse effect on color saturation of the display also since colors no longer can be displayed "pure" due to leakage.

Contrast on other hand stands for the "gamma curve" of the display. Usually the gamma curve is a logarithmic function and typical value is 2.2. But this value can change depending upon the type of display. For OLED the value of gamma curve can be anywhere between 2.0 ~ 2.4. Contrast adjusts the ratio of "white" and "black" levels of the TV. Increasing the contrast causes more levels of grey shades between pure black and pure white. Thus increasing picture quality for color images since more detailed color levels can be displayed.

Nxt2Impossible Blog by Nxt2Impossible is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at nxt2impossible.wordpress.com.

Samsung Vibrant Display Tear Down

2010-12-12T15:38:00.000-08:00

So, after owning this phone for last 3 days and having gone through all the tweaks and hacks on this phone I decided to test the display quality of this phone. Working as a display test engineer for living, I have couple of tools handy for making the measurements and analysis. The primary measurements (for those interested) were made using Konica Minolta CS-200 Chromameter, Ocean Optics Spectrometer and Xeon Lit Microscope. Here are the interesting results:

Manufacturer: Samsung

Model #: SGH-T959

Pixels : 800x480

Display Technology: Super Active Matrix OLED

Color Bits: 24

Gray Levels: 256

Total Color: 16Million (2 to the power of # color bits)

Diagonal Size = 4"

Aspect Ratio: 1.6

Contrast Ratio: 8,22,800

White Point: (0.27,0.30) 9688K

Color Gamut: 103% of NTSC 1953

Transfer Function (Gamma Curve): 2.3

GRAY VALUES:

Spectra and Color Channels:

The angular measurement on the phone gives a clue that the OLED technology used in the Samsung phone is also the best in the market. They seem to be using micro-cavity since there is 5nm shift in peak wavelength with 30 degrees of rotation.

Its interesting how the display world is improving from LCD to OLED technology and this presents a beautiful picture of how Samsung Galaxy is one of the premier engineering achievements in the mobile phone industry.

For heads-on comparison with IPhone 4 and Motorola Droid feel free to contact me or visit this link: http://www.displaymate.com/Smartphone_ShootOut_1.htm

	MAX Brightness				MIN Brightness
	Samsung Galaxy S				Samsung Galaxy S
	On Axis Nits	1931 CIEx	1931 CIEy		On Axis Nits	1931 CIEx	1931 CIEy
Blue	29	0.136	0.056	Blue	4	0.137	0.058
Green	237	0.218	0.723	Green	29	0.222	0.720
Red	78	0.676	0.324	Red	10	0.676	0.324
White	315	0.277	0.308	White	42	0.287	0.310

(All rights reserved by the author. If you find this useful...feel free to share. Do not copy or steal, it hurts and sucks!!! Author appreciates a healthy laugh and welcomes positive criticism.)

Nxt2Impossible Blog by Nxt2Impossible is licensed under a Creative Commons Attribution 3.0 United States License.
Based on a work at nxt2impossible.wordpress.com.