Not only was the initial diagram all/explaining, but the "pop"-"pip" on zoom-unzoom of the image was just as nice as playing with a sheet of bubble wrap.
Wow, and that ruler on the right side, even with the sound.
CRTs are still slightly magical to me. The image doesn't really exist. It's an illusion. If your eyes operated at electronic speeds, you would see a single incredibly bright dot-point drawing the raster pattern over and over. This YouTube video by "The Slow Mo Guys" shows this in action: https://youtu.be/3BJU2drrtCM?t=190
>The fact that they ever made it out of the research lab and into our homes is astonishing to me.
What is astonishing about LCDs? I don't mean to diminish the difficulty of scaling up the process, but if you think of early LCD displays they don't seem farfetched to be shipped to consumers.
I can appreciate these articles as they are but I personally don’t like them. They are junk food level of infotainment to me. Something I’d find on a Wikipedia summary section that covers general points.
A CRT - to name one - is a device whose actual understanding will challenge people in profound ways. To ask “how does a screen even work?” and to begin to answer this question will require a bit more than a summary form of “thing goes from point A to point B”. The history of this discovery is a stack of books and in and of itself is fascinating - the experiments and expectations and failures and theories as to why and how. I suppose I just expect more of the site. The illustrations are nice. Oh and my moniker is just a coincidence.
LCD on paper you see lots of drawbacks, in practice modern state of the art LCD for TV is pretty damn good. We will soon have RGB LED Backlight LCD with WHVA+ Panel that is about as wide angle as IPS, 95%+ REC 2020 colour, and 1-2ms response time.
Phosphorescent blue OLEDs should reduce current OLED display energy usage by 20-30%. But it still seems to be way off for phones and mass usage.
CRT displays are one of those analog technologies that are arguably much cooler than their digital successors. Think – a literan raygun, a particle accelerator, inside your monitor, creating the image you're looking at.
I have to take issue with the usage of the terms "pixel" and "subpixel" with regards to CRT. CRTs do not display discrete pixels. They display discrete scanlines, each one made up of a smoothly varying voltage across the line (and thus resolution is a function of both the DAC in the display device in the case of systems that generate a digital signal and then convert it to analog for display, and the hardware inside the CRT monitor). Also, there is no mapping between any "pixels" represented within that varying voltage and the separate color phosphor dots.
Even "digital RGB" isn't digital in terms of the CRT. It's only "digital" because each color channel has a nominal on and off voltage, with no in-between (outside of the separate intensity pin). However, the electron gun still has a rise and fall time that is not instant.
Displays didn't truly become digital for the masses until the LCD era, with DVI and HDMI signals. Even analog HD CRTs could accept these digital signals and display them.
I happen to have a stereo microscope at my desk, so I put my Pixel 9 under there. At 100x mag (10x ocular x 10x objective) it looks like there are 3 layers: as I move my head around slightly (so the image is moving over my retinas), the blue moves faster and the red almost stays still, with green somewhere in the middle.
The ticker on the right is quite nice, but I perceive the sound as coming from within my nose (if that makes any sense) to the point that I thought something was going on with my sinuses for a full 3 seconds, and got panicked.
There are some sentences in this that are technically vague enough to pass, but I don't think are strictly speaking correct, and I believe will likely lead to a mistaken understanding:
> modern displays don't paint the image line-by-line (...) They light up each pixel simultaneously, refreshing the entire display at once.
The entire screen area is lit all the time now, yes, but refresh still typically happens line by line, top to bottom [0], left to right [0], for both LCDs and OLEDs. It's a scanning refresh, not a global refresh (sadly).
You can experimentally confirm this using a typical smartphone. Assuming a 60 Hz screen refresh, recording in slow motion will give you enough extra frames that the smartphone camera also likely operating in a scanning fashion (rolling shutter) won't impact the experiment. On the recording, you should see your screen refreshing in the aforementioned fashion.
[0] actual refresh direction depends on the display, this is for a typical desktop monitor
I know this is HN, but I honestly clicked this link initially thinking it was going to be a detailed analysis of how screen plays are constructed and executed in football.
I'm much more interested in the hardware driver. This thing gets digital encoded input, has to decode it, and then multiplex it to 8 million pixels. 60 times a second. Being able to hit at least 4 million different levels (talking about 4K 60fps 12 bit color).
The input is roughly serial, so it takes a massive serial to parallel conversion.
Would be nice if you could give a hint on all the disabled chapters. Either a tooltip or even just a title attribute. Are they paid? Do I have to login? Not ready yet?
25 comments
[ 2.9 ms ] story [ 46.5 ms ] threadWow, and that ruler on the right side, even with the sound.
One of the nicest pages I have been on.
And the landing page... https://www.makingsoftware.com/
It just keeps on giving.
What is astonishing about LCDs? I don't mean to diminish the difficulty of scaling up the process, but if you think of early LCD displays they don't seem farfetched to be shipped to consumers.
A few decades ago I worked on a huge machine that made LCD color filters.
A CRT - to name one - is a device whose actual understanding will challenge people in profound ways. To ask “how does a screen even work?” and to begin to answer this question will require a bit more than a summary form of “thing goes from point A to point B”. The history of this discovery is a stack of books and in and of itself is fascinating - the experiments and expectations and failures and theories as to why and how. I suppose I just expect more of the site. The illustrations are nice. Oh and my moniker is just a coincidence.
Phosphorescent blue OLEDs should reduce current OLED display energy usage by 20-30%. But it still seems to be way off for phones and mass usage.
Even "digital RGB" isn't digital in terms of the CRT. It's only "digital" because each color channel has a nominal on and off voltage, with no in-between (outside of the separate intensity pin). However, the electron gun still has a rise and fall time that is not instant.
Displays didn't truly become digital for the masses until the LCD era, with DVI and HDMI signals. Even analog HD CRTs could accept these digital signals and display them.
Wonderful content and website otherwise!
> modern displays don't paint the image line-by-line (...) They light up each pixel simultaneously, refreshing the entire display at once.
The entire screen area is lit all the time now, yes, but refresh still typically happens line by line, top to bottom [0], left to right [0], for both LCDs and OLEDs. It's a scanning refresh, not a global refresh (sadly).
You can experimentally confirm this using a typical smartphone. Assuming a 60 Hz screen refresh, recording in slow motion will give you enough extra frames that the smartphone camera also likely operating in a scanning fashion (rolling shutter) won't impact the experiment. On the recording, you should see your screen refreshing in the aforementioned fashion.
[0] actual refresh direction depends on the display, this is for a typical desktop monitor
It’s late and time for bed! LoL.
The input is roughly serial, so it takes a massive serial to parallel conversion.
Would be nice if you could give a hint on all the disabled chapters. Either a tooltip or even just a title attribute. Are they paid? Do I have to login? Not ready yet?