Helmet-mounted displays

Cockpit, radar, helmet-mounted display, and other avionics
  • Author
  • Message
Online

SpudmanWP

Elite 5K

Elite 5K

  • Posts: 8349
  • Joined: 12 Oct 2006, 19:18
  • Location: California

Unread post13 Jun 2019, 17:30

I wonder how the new OLEDs will handle the issue?
"The early bird gets the worm but the second mouse gets the cheese."
Offline
User avatar

doge

Active Member

Active Member

  • Posts: 210
  • Joined: 13 Jul 2015, 16:07

Unread post13 Jun 2019, 17:52

Lt. Col. Pete Lee, 62nd Fighter Squadron Commander at Luke AFB, tells about the helmet. 8)




Offline
User avatar

botsing

Forum Veteran

Forum Veteran

  • Posts: 803
  • Joined: 05 Dec 2015, 18:09
  • Location: The Netherlands

Unread post13 Jun 2019, 18:14

SpudmanWP wrote:I wonder how the new OLEDs will handle the issue?

Two things that do wonders for OLED:
1. OLED does not have a backlight, so no bleeding from those lights with OLED.
2. Since the display is transparent it doesn't have a mirror layer and therefor doesn't need a polarizing filter to enhance the contrast, due to this the OLED display should be more transparent than LCD.
"Those who know don’t talk. Those who talk don’t know"
Offline

quicksilver

Elite 2K

Elite 2K

  • Posts: 2580
  • Joined: 16 Feb 2011, 01:30
  • Warnings: 1

Unread post13 Jun 2019, 22:48

SpudmanWP wrote:I wonder how the new OLEDs will handle the issue?


Green glow was a residual consequence of how the current/previous technology produced light.

Maybe this can help describe what the visual effect is like —

Imagine turning up the instrument panel lights in your car at night so you can see them but creating reflections on the inside of the windows that obscure your view out the windshield. When you try to turn the inst panel lights down lower to reduce the reflections, you lose sight of the instruments. So it is w green glow; when they turn the vhud image to its dimmest setting there is still enough residual light on the inside of the visor to obscure the thing they have to see outside — the FLOLS (‘the ball’).

The challenge in the system in low light conditions is about how the sensor (the night camera) reacts when there is almost no ambient light to capture/amplify. NVGs would start to produce scintillation, particularly the older generation systems. An inability to discern the horizon was not unusual under certain ambient conditions. Apparently there are other different effects the camera produces and projects on the visor. ‘Striations’ is how they are described, but involve both what and how the camera ‘sees’ and how what it sees is processed, projected and reflected in the visor.
Offline
User avatar

Dragon029

Elite 1K

Elite 1K

  • Posts: 1341
  • Joined: 22 Dec 2014, 07:13

Unread post14 Jun 2019, 00:40

An alternative way to demonstrate green glow is like this:

Attached to this post is an image of a night sky, with some stars on a pure black background:

mg0007-night-sky-with-twinkling-stars-animated-background_ekioupkse__F0000.png


If you look at that image (open it in a separate tab and press F11 to make it full screen; Esc to exit that mode) on a normal LCD computer monitor, in a room with the lights turned off, you'll see that even when your monitor is trying to display pure black, it's still very bright compared to the rest of your room. This all happens because the little liquid crystals that are meant to go opaque to block out the light, simply can't achieve full 100% opacity.

With the F-35's current LCD-projector tech, that very bright "black" is also being projected / reflected off the pilot's visor. What should just be some green lines and text on a fully transparent background is instead some green lines and text on a paler but not fully transparent green background.

This all happens because LCDs work by blocking light coming from light bulbs in the rear of your monitor. In older LCD displays there are fluorescent tubes in the edges of the monitor and they shine light through a plastic filter that spreads it out evenly towards the middle of the screen. If you've ever bought an "LED" TV or monitor, they're also LCDs, but they just use a grid of LED lights to create the same effect. Then, to control the colour, brightness, etc of the image on your monitor, every pixel on your screen has 3 little liquid crystal 'sub-pixels'; one is red, one is green, one is blue. To display a pure black pixel, those liquid crystals try to fully go opaque, but liquid crystals cannot achieve 100% opacity, so light gets through.

With OLEDs, there are no liquid crystals and there is no backlight (no fluorescent bulbs in the rear or grids of LED back lights). Instead, every pixel consists of microscopic red, green and blue LEDs and they just light up as much as needed. To display a pure black pixel, those LEDs just simply turn off completely and emit zero light.

So with the new OLED project tech in the F-35's HMDS, the symbology will still be lit just as well as before, but now the areas between text and lines will be vastly more transparent, because the only light that'll be shining onto the visor in those areas will be background luminance (lights shining inside his cockpit and reflecting off his face), which will be a tiny fraction of what the pilot experienced previously.

You can also see a similar result with your phone if you have an OLED / AMOLED display (Samsung Galaxy phones from recent years, the iPhone 10 family - any phone that features an "always-on display" with a clock still showing when the screen is off). If you open that same night sky image you should notice that if the pure black of the background blends seemlessly into the bezels / borders of your phone's display, because it's just (under the glass) black plastic bordering against black plastic.
Offline
User avatar

spazsinbad

Elite 5K

Elite 5K

  • Posts: 22957
  • Joined: 05 May 2009, 21:31
  • Location: ɐıןɐɹʇsn∀¯\_(ツ)_/¯
  • Warnings: -2

Unread post15 Jun 2019, 04:28

HMDS F-35 High Tech Helmet Pilot LtCol Lee 62FS CO 2019 https://www.youtube.com/watch?v=RVmLZekvdS4

RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
Offline
User avatar

spazsinbad

Elite 5K

Elite 5K

  • Posts: 22957
  • Joined: 05 May 2009, 21:31
  • Location: ɐıןɐɹʇsn∀¯\_(ツ)_/¯
  • Warnings: -2

Unread post16 Jun 2019, 02:35

F-35 Pilot's Flight Gear Explained & HMDS Luggage LtCol Lee '19 https://www.youtube.com/watch?v=PZcVRUiLd68

RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
Offline
User avatar

spazsinbad

Elite 5K

Elite 5K

  • Posts: 22957
  • Joined: 05 May 2009, 21:31
  • Location: ɐıןɐɹʇsn∀¯\_(ツ)_/¯
  • Warnings: -2

Unread post04 Jul 2019, 04:07

Article 'bout USAF pilot training is useful however I found this combination of cockpits most faskinatin'. From top left to right bottom we have TALON, Thunderchief, T-X and F-35.
Rebuilding the Forge: Reshaping How the Air Force Trains Fighter Aviators
28 Jan 2019 Gen. Mike Holmes USAF

Photo Captions: "T-38A Talon cockpit (left) and an F-105 Thud cockpit (right). The prominence of navigation instruments is apparent in both, with the F-105 also adding a radar scope for the pilot to manage. (U.S. Air Force photos, T-38 credit Tech. Sgt. Javier Cruz) A T-X cockpit (left) and an F-35 Lightning II cockpit (right). Navigation and system monitoring are greatly simplified by automation, leaving the pilot free to operate either “virtual” sensors in the T-X or actual sensors in the F-35."

Source: https://warontherocks.com/2019/01/rebui ... -aviators/
Attachments
TalonThudTXf--35pits.jpg
RAN FAA A4G Skyhawk 1970s: https://www.faaaa.asn.au/spazsinbad-a4g/ AND https://www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/
Previous

Return to F-35 Avionics

Who is online

Users browsing this forum: Google Adsense [Bot] and 3 guests