VFD Vacuum Fluorescent Displays

 Superior brightness, dimmable, multiple color options, they last a long time, some can go 200,000 hour with auto-dimming. Notably Toyota used a VFD as the speed display in the 04-09 Prius II in bright green that was inverted and the light bounced into a mirror for the drivers eyes, giving the impression that the displayed information was much further away in the middle of the firewall near the base of the front window, so that it was much easier to look upon quickly without taking your eyes away from the road ahead, not nearly as slick as a HUD displayed on the window, but close, and our 1996 microwave oven has a superior multi color VFD display with 8 bit microcontroller able to scroll text across the display, the coolest VFD I have ever seen but not nearly as bright as the one in our 05 Prius that I drove for 17 years.

Nixie tubes were an example of a cathode display, perhaps a technological precursor to the vacuum fluorescent displays. I believe that cold cathode fluorescent backlight tubes of perhaps 1mm or 2mm or 3mm in diameter arrayed behind LCD screens in early flat screen computer monitors and televisions uses a similar design in terms of electrical ionization of phosphors. In a VFD a glass housing containing cathode wires in front of the information display panel bombard the information display panel phosphors with electrons causing them to glow. If the VFD controller varies the voltage to the cathode wires then the information panel glow can be dimmed or brightened. This entire setup like a vacuum tube, is held inside a rectangular vacuum pressure glass ampule with wires bonded through the glass in a hot melt manufacturing process where they use a fluorescent inspection tool to check for stress fractures in the glass, as the VFD has to be annealed like other glass produce to remove heterogenous stress boundaries that the prolonged heating during annealing causes to relax and melt back together into homogeneity. I skipped a lot of the steps in VFD making because one, I never made one, two I only researched them after they stopped being used in products and replaced by stupid segmented LED displays that are shorter life and where one segment of LED tends to burn out before the others distorting the displayed information which I find extremely annoying. 

Replacing the LED display in a microwave oven requires taking the entire controller off & carefully unsoldering it, procuring a replacement, then carefully soldering the new display onto the control logic board, not something an average person can do, and if you took it to a repair shop they would charge more to fix it than the cost or replacing the microwave oven with a newer model. This in wealthy countries often the case, it costs more to fix your older appliance than it dose to replace it with a new one. Can you say designed obsolescence? The euphemism that device manufacturers used is Lifecycle Analytics. Even as a kid my father Ken told me, in the 1960s manufactures learned their lesson when they sold Americans things that last 50 years or more, so they only make 1 sale to that person, and have to charge a lot more for such things to generate enough revenue or profit to stay in business. 

He had a  stereo amplifier from the 1960's that cost $1000 back then, was still working in the early 2000's even with a lot of hours on it. Eventually some of the robust well made in American transistors burned out, so it took it to a local electronics repair shop on a Saturday and took me with him. At the repair shop the repair technician said "Here's is the deal, if we used really high quality Allan Bradly American Made long life transistors they are about $20 each and you need 12 plug labor to install them after removing the old ones, or I can use some cheaper made in Asia transistors than only cost $3 each plus the same cost for replacement labor, what would you like me to do. My dad whet with the cheaper option, but then it burned out 5 years later. We then went to the Trading Musician in Seattle and found a better older amp with low hours in minty conditions for $100 and it still works today :) 

I grew up visiting many homes because my parents were relators and being observant I noticed that many home appliances made before 1980 just keep going. I asked a family friends who was a product design engineer about this and he said "Back before 1980 computers were not able to do FEA or finite element analysis as well as they can now, so manufacturers built in more tolerance or made everything stronger, thicker & heavier back then to make sure they would work until the warranty ran out. Over time they figured out how to use the least amount of metal possible or in well made examples that last a long time you have to pay a huge price premium, so you can still today buy really well made long lasting stereo amps made from raw materials in New York, but that famous company charges many thousands of dollars for their amps. 

Everyone says how energy efficient LED are compared to other technology, but exceptional examples of Sodium Vapor Lamps with long life well made magnetic ballasts were know to get 200 lumps per watt of electrical energy since the 1970's. Take that LED you stupid bunch of rare earth nonsense. I hate blue white 6500 K led, the blue light garish and ugly and reminds me of hospitals, I don't want that in my vehicle or at home. I like 2000K warm sunset beautiful flame fire color, orange red colors, or even 3500K bright white or 3000K warm white, and even 4200K greenish light ok, its that 5500 to 6500K blue white that is super annoying. Now there are interesting purple pink colors above 7000K that I also like. How can I be so color specific with preferences, well given that the eye is more sensitive to brightness and contrast than it is to colors, its probably down to why high CRI HID lams or short arc xenon bulbs are used in LCD and DPL projectors with more lumens or higher brightness. 

I know that LED projectors exists, but lasers are superior in terms of brightness and way long ago & even today the short arc xenon in its brightest format used in operating theaters, clean rooms & in IMAX projector systems. The coolest bulb design of all time goes to the Microwave Sulfur bulbs, where yellow sulfur held inside a rotate quarts sphere of thick fused quartz, where microwaves from an adjacent emitted excite the sulfur into a plasma that emits millions of lumens of pleasing light color light :) There is an airfare museum with a few of these microwave sulfur bulbs that are so bright that they used polished metal optical pipes to move the light around the facility to distributed it, such that a few microwave sulfur bulbs are able to illuminate the entire inside of the giant building complex with optical fiber like polished metals tubes pumping the light around. Amazing. 

Even high CRI LED exist, where the manufacture color bins the LED chips. LED chips are made on large wafers like computer chips, but they sprinkle a mix of phosphors over the blue UV LED chips so that the UV light energizes the phosphors to emit white light of different color temperatures depending on the phosphorus used or how many different colors of phosphors are applied, but because of irregular application of the phosphor, some of the LEDs have slightly different color temps, so a optical sorting testing system can separate them into groups with closer color temp colors, called color binning, but doing that takes longer and costs more, so high CRI professional LED for printing and studios and color accuracy, cost a lot more like photography bulbs.