Panasonic 2500 Hz Focused Field Drive in Plasma — A Similar Goal

Speaking of impulse-driven technologies, Panasonic Germany has several very interesting videos of various technologies of their high-end plasma (2500 Hz focussed field drive – FFD) and LCD displays (1600 Hz scanning backlight) – multiples of the European refresh rate of 50 Hz.  Although the Hz should be taken with a grain of salt, as actual measured motion blur reduction can fall short of the claims, the theory and science is still very real — compressing the impulses into a short time period.  It is very nicely explained in German by this Panasonic employee:

Some plasma displays such as Panasonic VT50 uses this. This plasma display focusses the subfield refreshes into a single 0.4 millisecond time period  (1/2500th of a second) — a very similiarly short time duration that the BlurBusters experimental ultrahigh-performing scanning backlight, is also targetting.


Over 1000 watts of LED ribbons ordered!

Three different brands of LED ribbons have now been ordered from several suppliers.  The current working goal is to create a backlight that is 150 watts per square foot, with 10,000 lumens per square foot.   The brightest ribbon I’ve ordered is 22 lumens per LED, and 900 LED’s will be put in a 23″ computer monitor.  LED’s can also accept surge current for short time periods to provide over 50 lumens per LED.  For ultra short strobes, I can exceed 25,000 lumens per square foot.  This is enough strobe wattage to make LCD have less motion blur than CRT.

Total amount of all orders is 80 meters of LED ribbon (4,800 LED’s at 60 LED per meter, using brighter #5050 LED’s instead of dimmer #3528 LED’s), which is enough for at least three computer monitors.  Some are actually for R&D — including backlight diffusion tests, brightness tests, and overvoltage failure tests.

High wattage is necessary to more accurately emulate CRT scanning flicker using a scientifically proper sequential scanning backlight (FAQ) — see how ultra-brightly CRT phosphor shines for a short period in high-speed video of CRT scanning.  Less than 50% of existing scanning backlights have significantly noticeable blur elimination, and most scanning backlights dim the picture.  The BlurBusters scanning backlight design is scientifically targeted at the goal of maximum motion blur elimination, with minimal disadvantages.


How to disassemble an LCD

Designing a scientifically proper scanning backlight from scratch, for an existing LCD computer monitor, requires disassembling LCD’s.

There is an LCD parts store page that has info useful during my research, including a YouTube video on how to disassemble LCD panels for backlight replacement (including replacing a CCFL backlight with an LED backlight). The video shows disassembly of an LCD panel. The concept is similar, except I’ll be adding lots more backlight wattage (my design for an inexpensive 240 watt LED backlight for 23″ monitor using LED ribbon), and modifying an existing computer monitor such as Asus VG236H. There are many other videos on YouTube that instruct on how to disassemble an LCD, such as this video on replacing a broken backlight.


Sneak preview of Arduino Input Lag Meter!

Coming soon: How to build your own Arduino-powered input lag meter using a photodiode! No soldering needed. Cable latency accuracy of +/- 1 microsecond and input lag accuracy of +/- 0.1 millisecond (once zero-calibrated with a CRT display first on the same system).

Screenshot of early prototype.
New system now has 3 flashing squares, full screen, no title bar.

Even the operating system latencies (e.g. Windows compositing, double buffering) does not appear to matter, provided you zero-calibrate with a CRT first, keep using the same graphics driver, and the window is always centered. The relative input lag latencies stay accurate to +/- 0.1 millisecond. You simply place the photodiode on the screen, and the software detects when the photodiode is pressed against the screen.

EDIT: New version of Blur Busters Lag Tester no longer requires CRT for zero calibration!
EDIT2: Cable lag now reduced to less than 1 millisecond, via a Teensy 3.0!
EDIT3: New version now has three flashing squares, similar to a Leo Bodnar unit. However, the big advantage is that the Blur Buster Input Lag Tester will work on anything a computer can output, including 4K, 120Hz, 85Hz, 2560x1440p, even laptop LCD’s.


240 watts of LED backlight for a 23″ computer monitor!

[This is a very old article from scanning backlight experiments in 2012]

A 23″ LCD computer monitor is 286mm high x 508mm wide. From math calculations on LED ribbons (120 LED per meter, 6mm wide, 6500K, ~10watt/meter, 80+CRI available), one can put 48 rows of 6mm-width ribbon segments behind a 23″ LCD. That’s a whopping 240 watts of backlight for a 23″ computer monitor!  

This will allow 90% motion blur reduction using ultra-short scanning backlight strobes (see FAQ) without a dim picture, 1.6ms strobes at 60Hz, resulting in 24 watt average actual power consumption. Many new 23″ LCD monitors with a LED backlight, adjusted to a comfortable brightness, consume just about 15-20 watts for the backlight itself. I will have brightness left over to go to 95% motion blur reduction, using 0.8ms strobes at 60Hz native refresh (simulating equivalence to 960Hz), or 0.4ms strobes at 120Hz native refresh (simulating equivalence to 1920Hz).

LED ribbons are cheap (search eBay, Alibaba, Google for “LED ribbon”). If you know another inexpensive alternatives of putting nearly 300 watt of backlight behind a 23″ monitor, contact mark[at]scanningbacklight.com