我不知道为什么，但是我无法将亮度设置为超过 30%。
该包xbacklight确实收到将亮度设置为 100% 的命令，但实际上从未发生过。
有趣的事实：如果我使用不带电池的笔记本电脑并取下充电器一秒钟，亮度会短暂地达到真正的 100％ 状态。
亮度设置显示亮度在30%左右，其实：
lsb_release -a：
Distributor ID: Ubuntu
Description: Ubuntu 20.10
Release: 20.10
Codename: groovy
/etc/X11/xorg.conf：
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "Backlight" "intel_backlight"
EndSection
lspci：
00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 02)
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02)
00:19.0 Ethernet controller: Intel Corporation 82577LM Gigabit Network Connection (rev 05)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05)
00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 05)
00:1c.3 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 (rev 05)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5)
00:1f.0 ISA bridge: Intel Corporation QS57 Chipset LPC Interface Controller (rev 05)
00:1f.2 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode] (rev 05)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05)
00:1f.6 Signal processing controller: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem (rev 05)
01:00.0 Network controller: Qualcomm Atheros AR9485 Wireless Network Adapter (rev 01)
02:00.0 Network controller: Broadcom Inc. and subsidiaries BCM43224 802.11a/b/g/n (rev 01)
03:00.0 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller (rev 01)
3f:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
3f:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
3f:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
3f:02.1 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor QPI Physical 0 (rev 02)
3f:02.2 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor Reserved (rev 02)
3f:02.3 Host bridge: Intel Corporation 1st Generation Core i3/5/7 Processor Reserved (rev 02)
答案1
检查是否有某些桌面电源管理器覆盖了这些设置。我不知道 Lubuntu / LXDE 的情况，但在 Xfce 和 KDE 中有一个“电源管理器”小程序，可以在其中定义降低屏幕亮度以适应各种电源情况：使用墙上电源、使用电池、电池电量低、电池电量极低。
https://manual.lubuntu.me/stable/3/3.2/3.2.12/power_management.html
这里有各种建议：
高血压
答案2
lxQt 亮度设置有一个主滑块，用于定义所有显示器的最大亮度。
虽然出于某种原因，我无法使用此滑块，如果启动lxQt 亮度设置从终端 ( $ lxqt-config-brightness) 以外的任何地点。
因此，每次我尝试增加此主滑块的值时，设置都不会保存，并且主滑块会回到 30%。
截至目前，我已经从终端启动了小程序并将主滑块设置为 100%，现在，我可以在显示器上使用 100% 亮度。
我不知道为什么这个小程序没有按预期工作。
