Take A Look at the display on your car stereo next time you're in your vehicle. Can you read it really easy? How about when the sunroof is open and the sun is shining right on it? Bright, readable displays have been one of the few things that the OEM guys have managed to do a good job with (the other is the volume knob).
As the aftermarket guys pulled out the stops to make their decks wilder and better than stock, displays also changed, using multi-color graphics and even reverse displays. Problem was, some of these just couldn't be seen in bright light or off axis. It's hard to change the station when you can't see what station you're on.
A couple years ago, Car Audio & Electronics wrote about a breakthrough display technology called Organic Electro Luminescent or OEL, first brought to market by Pioneer. Today, quite a few Pioneer CD players feature this OEL technology. What was once an expensive display is quickly being trickled down to more affordable units - and that benefits all of us. You can get a Pioneer DEH-P6400 CD player with a four color OEL display for as little as $280.
Other manufacturers have also jumped on board. Kenwood currently has just one model, the KDC-X959, with a large OEL display. They are considering other less expensive units for sale in 2003.
Sony has taken a bit of a different direction with their new display in the MEX-5DI. It uses a more conventional TFT (thin film transistor) display. This is what in-car monitors are made with. It displays an awesome 32,000 colors and covers a good amount of real estate on the faceplate.
Both the Sony and the Pioneer units allow you change the graphics on the display. The Pioneer units require a trip to the dealer to get images into the deck. This is kind of cool because you get to go visit your car audio dealer more often. There may be a charge associated with loading an image(s) on your new deck, but if your dealer loves seeing your face, he may do it for free!
Sony's MEX-5DI has a MemoryStick slot. You load whatever graphics you want from your computer to a MemoryStick you purchased using a MemoryStick reader/writer. Insert the stick into the deck and it will load the new images. You can even load up to a five second MPEG movie.
TFT technology is really nothing new, it's been used in laptops and now extensively for in-car monitors. TFT's biggest drawbacks are cost and power consumption. If you've ever wondered why laptops cost so much more than a desktop computer with the same speed - most of it is due to the large display.
In a laptop power consumption can be an issue because most of the power is needed to run the display. But in a vehicle where you have a constant or plugged in power supply, it's something you don't have to worry about. The heat a TFT generates could be a problem. If you've ever ejected a really warm CD, then you know these decks can get hot. Sony says the heat problem is not a factor, because the display isn't large enough.
A TFT display works by applying voltage to transistors which illuminate either red, green or blue. A combination of those three colors is all that's needed to display all the colors we see. The added part of a TFT display is the backlight which is needed for you to see the illuminated transistors. This is what consumes so much electricity. But when you look at TFT at an angle, the backlight isn't as transparent, causing the display to "wash-out" when you view it from an extreme angle.
OEL is a fantastic new technology that has already spread out to cell phones and will soon appear in lots of other small devices. Currently, its biggest challenge is full color. Unlike the TFT which can display so many colors, the current units that Pioneer and Kenwood produce display four colors each in its own separate zone.