6 ms·

Not to crap on an inventive kid, but I don't get this. A normal LCD screen works by shooting a backlight (usually LEDs) through an LCD panel. All this project

Not to crap on an inventive kid, but I don't get this. A normal LCD screen works by shooting a backlight (usually LEDs) through an LCD panel. All this project does is replace the backlight with either a reflective backlight, or ambient light if it's bright enough. So how could this be any improvement beyond just turning down the brightness on a plain old LCD screen?

neogodless 3y ago
I think it would make sense if screens detected ambient light and adjusted brightness to match (like smart phones do....) so this is just a clever way to do just that with low tech. But a high price. So yeah, I think it might just be better to take the existing technology in smart phones and apply it to laptop and desktop screens.
- lupire 3y ago
  Monitor screens do this, if you don't get a cheap one.
  - FirmwareBurner 3y ago
    I have a cheap monitor with this feature and I think it sucks. It never manages to set the exact brightness I would consider right for me.
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jfim 3y ago
It automatically adjusts to ambient light, which isn't common on desktop monitors afaik. I wonder if one could just replace the backlight by a mirror though.
hex4def6 3y ago
There is no improvement. There are a lot of negatives though. For starters: * transmissivity of an LCD panel is pretty bad (10%-25% transmissivity?). So this is always going to be extremely dim, unless you stick a really bright lamp right up close to it. Thus, this isn't "matching" ambient light in any way. * Brightness uniformity is going to be terrible unless you use a photography softbox lamp. * Color accuracy is going to be terrible. Monitors use LEDs that are extremely cold / blue (~6500K if I remember) to get good color reproduction over the entire range of possible colors. Unless you want your house to look like an operating room you probably won't use a lamp that comes close to reproducing that. This is a solved problem in cellphones. Put a $0.25 ALS in the front bezel, enable DDC/CI, and call it a day. Here's a product idea that actually solves the issue: make a little USB dongle that has an ALS in it, make it in a formfactor that allows you to clip it to the top of any monitor, and use that to control the brightness. For DDC/CI monitors, you can directly control the backlight, and for other monitors you can just fake it by reducing the brightness of the image.
- nomel 3y ago
  I actually did this exact thing, 20 years ago, with a monitor that had a dead backlight. I took it apart and tried angling a mirror with a diffuser on it (similar to what's shown), but ended up using white paper on the back, and a light/window behind, normal backlight style. Why? Because, all your points are correct (although the lack of uniformity was pretty ok/analog). And, as the images in the article show, you can't get reasonable brightness without a high powered light behind it. Oddly enough, the images in the article, with the light above and a poor angled reflector in the back, show maximum possible blinding glare, with the bulb shining right in your face. It was temporary, fairly terrible, experience. A high quality monitor, with auto brightness and ambient color matching (like anything from Apple) would be my preference (and current use).
  - TaylorAlexander 3y ago
    The day before the 2005 robo games in san francisco my laptop's backlight went out. In order to operate my robot I had to disassemble the screen and use a flashlight to light it up!
lupire 3y ago
I don't know what it's like in China, but in USA this would be a "college application project" to get him into Harvard and then close down the nonstarter company.
- fooker 3y ago
  This will get him into an Ivy league or equivalent university pretty easily.

neogodless 3y ago

I think it would make sense if screens detected ambient light and adjusted brightness to match (like smart phones do....) so this is just a clever way to do just that with low tech. But a high price. So yeah, I think it might just be better to take the existing technology in smart phones and apply it to laptop and desktop screens.

lupire 3y ago
Monitor screens do this, if you don't get a cheap one.
- FirmwareBurner 3y ago
  I have a cheap monitor with this feature and I think it sucks. It never manages to set the exact brightness I would consider right for me.
- deleted 3y ago
  [deleted]
- deleted 3y ago
  [deleted]

jfim 3y ago

It automatically adjusts to ambient light, which isn't common on desktop monitors afaik. I wonder if one could just replace the backlight by a mirror though.

hex4def6 3y ago

There is no improvement. There are a lot of negatives though. For starters: * transmissivity of an LCD panel is pretty bad (10%-25% transmissivity?). So this is always going to be extremely dim, unless you stick a really bright lamp right up close to it. Thus, this isn't "matching" ambient light in any way. * Brightness uniformity is going to be terrible unless you use a photography softbox lamp. * Color accuracy is going to be terrible. Monitors use LEDs that are extremely cold / blue (~6500K if I remember) to get good color reproduction over the entire range of possible colors. Unless you want your house to look like an operating room you probably won't use a lamp that comes close to reproducing that. This is a solved problem in cellphones. Put a $0.25 ALS in the front bezel, enable DDC/CI, and call it a day. Here's a product idea that actually solves the issue: make a little USB dongle that has an ALS in it, make it in a formfactor that allows you to clip it to the top of any monitor, and use that to control the brightness. For DDC/CI monitors, you can directly control the backlight, and for other monitors you can just fake it by reducing the brightness of the image.

nomel 3y ago
I actually did this exact thing, 20 years ago, with a monitor that had a dead backlight. I took it apart and tried angling a mirror with a diffuser on it (similar to what's shown), but ended up using white paper on the back, and a light/window behind, normal backlight style. Why? Because, all your points are correct (although the lack of uniformity was pretty ok/analog). And, as the images in the article show, you can't get reasonable brightness without a high powered light behind it. Oddly enough, the images in the article, with the light above and a poor angled reflector in the back, show maximum possible blinding glare, with the bulb shining right in your face. It was temporary, fairly terrible, experience. A high quality monitor, with auto brightness and ambient color matching (like anything from Apple) would be my preference (and current use).
- TaylorAlexander 3y ago
  The day before the 2005 robo games in san francisco my laptop's backlight went out. In order to operate my robot I had to disassemble the screen and use a flashlight to light it up!

lupire 3y ago

I don't know what it's like in China, but in USA this would be a "college application project" to get him into Harvard and then close down the nonstarter company.

fooker 3y ago
This will get him into an Ivy league or equivalent university pretty easily.