1. Display Technologies

2. What it is
Collection of parts and software designed to put a picture on a screen
Monitor shows you what is going on with software (and OS)
Primary output device for PC
Video card, or Display Adapter handles communication between CPU and monitor

3. Phosphor Coating on inside of tube
CRT Monitors
A LOT of high voltage, resist the urge to take it apart!
Electron Beam
Electron Guns (3)
Shadow Mask
Yoke
Phosphor Coating on inside of tube

4. How it works Electron gun fires a beam of electrons
Path of electrons is shaped by the yoke (bent)
Electrons strike the phosphors and make them glow
Phosphors have persistence so they continue to glow after electron beam stops

5. Refresh
Electron beams sweep from left to right – across then down to next line
Raster Line
Horizontal Refresh Rate
KHz
Vertical Refresh Rate Hz

7. Adjustments
Try not to do it; the manufacturer knows better than you do.
The video card “pushes” the monitor – that’s where changes are made

8. Resolution
Number of horizontal pixels by the number of vertical pixels
640x480
800x600

9. Aspect Ratio Ratio of horizontal to vertical pixels
4:3 for CRT and many LCD monitors
16:9 for wide-screen monitors (same as theaters use)

10. Dot Pitch
One significant measure of value of monitor: more expensive = lower number
Dot Pitch
In millimeters
Dot pitch of .28 or less gives a nice, sharp image.
At .35 it seems like you can see the dots (TV image)

11. LCD (Passive) Monitors
Light travels in waves (one definition)
Liquid crystals tend to align with grooved surface or electric field.
Aligned crystals will allow light to pass through (no electrical potential)
Apply electrical potential and no light passes through
This is digital, rather than analog of CRTs

12. LCD Pixels

13. Passive Matrix Wires in “Y” and “X” directions
Voltage on wires allowed light to pass
Slow response: “smeared” image
Laptops for early years and watches today

14. Thin Film Transistor (TFT)
Also called Active Matrix
Vast improvement over Passive Matrix
One, or more, transistors control each color dot
Twisted nematic gives fair display for reasonable price – use 18 bits, not 24
In-Plane switching (IPS) gives true picture
Brighter, better contrast, faster, more colors and wider viewing angle

16. LCD components LCD panel (what you see)
Backlights (so you can see the display in low-light conditions) – cold cathode fluorescent lamp (CCFL)
Inverters send power to the backlights (DC-AC)
3-row, 15-pin connector is analog and must go through a analog to digital converter; DVI and HDMI are digital

17. LED monitors Light-emitting diode Another form of backlighting
Can be an array across the screen or around the edges
Don’t need AC power, so no inverter(s)

18. Resolution LCDs have a native resolution – looks best there
Mine is 60 Hz (19”)
Can run lower resolution, but picture sharpness suffers – even with edge-blurring (anti-aliasing)
Object size does not “grow” quite as quickly as monitor size

19. Other Measures Contrast Ratio: Bright to dark 700:1
Brightness: 400 nits or 400cd/m2
Response time: 4 ms
Refresh rate: 24Hz for movies, 60 Hz for monitors which leads to 120Hz monitors

20. Projectors Lumens = brightness of projected image
Throw = size of image at a certain distance from projector
Lamps get hot quickly, need a fan to cool them and are expensive to replace

21. Plasma Display PDP – Plasma Display Panel
Wider viewing angle and richer picture than LCD panels
Use a lot of electricity
Suffered from “burn in” issues where image “ghosts” on the screen
Overscan (picture larger than display) can cut off the taskbar
Not a good choice for PC monitor

22. Monitor Size CRT’s are smaller (for same size) than LCDs
Viewable image size 15.5”
Screen Size
CRT
LCD
Monitor size 17”
15” screen size

23. Graphics Processing Unit
Connections
CRTs only use analog, 15-pin connector
LCDs can use either analog or digital connector – DVI-I
Video cards use RAMDAC to convert digital to analog for display
Graphics Processing Unit

24. Power Conservation
Turn off the CRT to reduce power consumption or when you walk away
Burn-in of image is a long lost art. Used to happen on older monitors.
Typical CRT uses watts; LCD’s use watts

25. Adjustments On/Off switch Brightness and contrast buttons (CRT)
Menu activate/select button for on-board menu system
Seldom is there a “reset” button, so be careful

26. Video Cards Or Display Adapters
Three parts: Video RAM, video processor circuitry and RAMDAC
Early cards just shuffled BIOS bit-maps to the screen (put a dot here, and one there)
Used small amounts of RAM
80 characters by 24 rows

27. Color Depth 16 colors = 4 bits 256 colors = 8 bits
64k colors = 16 bits
16.7 million colors = 24 bits
VGA mode is 16 colors

28. AGP (PCI – 32-bits at 33MHz) Accelerated Graphics Port
Single slot, never two
66 MHz, 32-bits wide
Uses strobing for 2x, 4x and 8x transfers on each clock cycle 21

29. On its own bus

30. Video RAM VRAM – Video RAM – allowed read/write at same time
WRAM – Windows RAM – optimized for moving windows around – died quickly
Replaced with DDR, DDR2, GDDR3 and GDDR4, GDDR5 SDRAM

31. Graphics Processor
Can be done by CPU (for on-board graphics) but not efficient
ATI and NVIDIA make most GPUs
New GPUs come out often; a challenge to keep up with models
More dollars = newer GPU
CPU with GPU = Accelerated processing unit (APU)

32. PCIe x16 Serial communication 16 “lanes” or channels
Replacement for PCI bus as cards become available (x1 and x4 variants)
SLI – its either Scan Line Interleave or Scalable Link Interface – two video cards (matched set)

33. Display Port and HDMI Mac desktop models and some Dell
Big brother is the Thunderbolt connector
High Definition Multimedia Interface (HDMI) – video output like DP

34. Installation Read the install manual first, not later!
Remove old drivers first. Reset system to VGA mode on existing card
Install new drivers
Install new card
Finish driver installation
Try to keep other cards away from video

35. Name tags Vista: Personalization
7 and later: Display and Personalization

36. Display Applet

41. Drivers
Windows can crash and require a re-install of OS simply by installing a new video card and not uninstalling the old video drivers first.
Go to Add/Remove Programs to uninstall video driver. (Step 1)
Insert CD for new card and start driver installation. (Step 2)
Stop system where directed and install card. (Step 3)
Finish driver installation.

42. If the Card went bad Can’t get to Add/Remove programs.
Have to install card to get working display.
Start up in Safe Mode; you can delete drivers in this mode.
Load drivers for new card.

43. Color Correction Also called color temperature
Device that fits on monitor and looks at the display
Graphic artists use these so they can set colors exactly.

44. 3-D Games
Started with sprites – still images of an object; multiple images used to create depth
True 3-D uses vertices to define points on an object which are then “edged” with flat polygons
Last step is to cover the edges with texture(s)
Takes a lot of computing horsepower

45. 3-D Video Cards
Graphical Processing Units (GPU) to do the 3-D rendering tasks
Lots of RAM to store textures
We need standardized command sets to allow communication between game and video card:
OpenGL for UNIX, then PC’s
DirectX API (Application Programming Interface) from Microsoft

46. DirectX Supports Video, Sound, Network connections and Input devices
Provides common interface for games – don’t have to write to specific video card
Vista/7 wants DirectX 10, not 9.0c which most had in XP
Dxdiag to determine version of DirectX and other stuff about DirectX 4

47. Troubleshooting Cards
Video cards seldom fail, but might
Often a driver issue – Windows cares about video card, but not monitor
You can go to Programs and Features to delete video driver
Try Safe Mode to see if problem “goes away” – then you know it is driver (or setting)
Try another monitor – often a hassle, but well worth the time
Check the settings for resolution, refresh & color

48. Troubleshooting CRTs
Try another monitor, then get another monitor – don’t try to fix them, the dollars don’t work out
Check the signal cable connections – loose cable will color the screen or miss colors
Client with no video turned out to be failure to start up

49. And Now… Plasma Display Panels Digital Light Processing (DLP)
Large screen sizes
Miniature florescent lights – three per pixel
Uses as much power as CRT
First ones had bad habit of burning out
Digital Light Processing (DLP)
One mirror for each pixel
Don’t know how they move, but they do