Re: Screen Shade/curtain?

Pranav Lal

Hi all,

One way that has worked for me in the past is to hit windows key + p and then to choose an external display. The screen does turn off. You have to then do this upon every reboot.

In addition, several years ago, a company called Techno-Vision in the UK made a physical device that would turn off the screen. It still works. It plugs into the display port of a laptop and is treated like a display. See and ask them if they still have the device.

The problem with an app solution is that on many corporate systems, it is difficult to install because you need permission.


-----Original Message-----
From: [] On Behalf Of Kevin Cussick via Groups.Io
Sent: Monday, December 18, 2017 3:26 AM
Subject: Re: [nvda] Screen Shade/curtain?

it does not work on my 2 all in ones and I tried a little program on my laptops that should do this but it didn't work. I think it should be in nvda and Joseph for you just to say that you won't consider it if people say other screen readers have it is very heavy handed.

On 17/12/2017 21:24, Joseph Lee wrote:
Sure, turning off the monitor may work, but not always.

-----Original Message-----
From: [] On Behalf Of
Didier Colle
Sent: Sunday, December 17, 2017 1:21 PM
Subject: Re: [nvda] Screen Shade/curtain?

Hi Joseeph,

Thanks for the clarification.

Indeed, showing a blank window would not save energy. But why not simply switching off the screen (power button on an external monitor, or using the Fn+F7 (or similar key combination) on a laptop? Then you have both advantages, the pseudo "privacy" thing, and the energy saving.

I agree with the rest.

If an add-on would be needed, then I believe it is more worth
investing in an add-on that can report the status of the screen
(backlight level, to what port/screen the video signal is send), a bit
like the battery level feature in NVDA (nvda+shift+b)

Kind Regards,


On 17/12/2017 22:04, Joseph Lee wrote:
As noted by some members, screen shade/curtain shows what appears to be a blank screen. This is used to "guarantee" privacy for screen reader users. Note the quotation marks around "guarantee", as it does not really guarantee privacy, as there are means to circumvent this (speech output, braille displays, remote access, etc.).
From what I can gather, this function does not result in extended battery life nor power savings. When this function is turned on, an overlay window is imposed on top of other windows, and turning this off removes this overlay. As I said above, this does not provide privacy as many of you may think.
As for this being part of a screen reader: my overall opinion is that it should not. If people want it, then I think an add-on would be a more appropriate solution. Only after looking at justifications and costs should developers consider adding this into NVDA, in my opinion, and personally for me, a justification that goes along the lines of, "because another screen reader has this" is something I won't even consider.

-----Original Message-----
From: [] On Behalf Of
Didier Colle
Sent: Sunday, December 17, 2017 6:37 AM
Subject: Re: [nvda] Screen Shade/curtain?

Hi all,

I am not sure what this functionality is exactly about.

When it is about switching off / dimming the monitor, I do not understand why it would not save on battery....

The backlight of a monitor in a laptop, tablet, smartphone, ... whatever is one of the main power sinks in such systems.

On a laptop, you can often (this may vary between laptops) use Fn+f7
for switching between different display modes (signal send only to
laptop monitor, signal send to external monitor only or signal send
both) or
Fn+F5 to dim the backlight and Fn+F6 to light it up.When I am on
power for a long time, I dim the backlight with Fn+f5 to save battery.

Thus you don't need a NVDA add-on for that, although such add-on may
be useful to read the status of the screen (to which monitor is the
signal send, on what level is the backlight). I have no clue whether
windows has access to such info, let alone it provides an api to
request that info (it might be the case that on some laptops this is
a pure BIOS feature completely transparent to windows).

Once again, I am not sure what this functionality is supposed to be
exactly, and thus I may be speaking about something completely different.

Kind regards,


On 17/12/2017 9:24, Brian's Mail list account via Groups.Io wrote:
From what I know about Windows and indeed most screenreaders, this
function is just for privacy, ie its not going to save any battery.
If that is what you want then I'd have thought it was possible to do
it, kind of like a screensaver that never actually loses focus but
then you need to be able to tell nvda that you want it to use the
invisible window not the visible one.

In the issues tracker there is a thread on this.
Also the ultimate way |of doing this on a desktop is called the
monitor off switch..... ahem.

Sent via blueyonder.
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in the display name field.
----- Original Message ----- From: "Kevin Chao"
To: <>
Sent: Saturday, December 16, 2017 11:30 PM
Subject: [nvda] Screen Shade/curtain?


VoiceOver has had screen curtain feature for a long while and JAWS
recently got screen shade.

Does NVDA have a similar feature via an add-on or natively?

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