Nvidia Optimus with GTX 850m not working

I recently got a new notebook (Acer Aspire V5 573G) with a Nvidia Geforce GTX 850M and the Intel Haswell integrated graphics.
Now I read through a lot of websites in order to find out what the best way is to get the system running. Usually, I wont need the GeForce card so that the intel one is good enough. However, I think the Displayport and the HDMI port are wired to the Nvidia card, so I need that one to work as well.
Problem is, the Nvidia card is not detected by Ubuntu: Output of lshw -C display:

*-display

       description: VGA compatible controller
       product: Haswell-ULT Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 0b
       width: 64 bits
       clock: 33MHz
       capabilities: vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0

       resources: irq:65 memory:b3000000-b33fffff memory:c0000000-cfffffff ioport:5000(Größe=64)

The best thing for me would be, that the Nvidia card is constantly turned off but can be activated so that i can use HDMI/Displayport. I already tried to install bumblebee, but -of course- the card is not detected.
Please tell me if you need any further information.
Thanks a lot!

EDIT: Output of uname -a:
Linux LappII 3.13.0-52-generic #86-Ubuntu SMP Mon May 4 04:32:59 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

I think the problem is that current version of Nvidia drivers in Ubuntu does not support this card. You can try to install a newer version.
Run in terminal.

sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
sudo apt-get install nvidia-346
sudo add-apt-repository -r ppa:xorg-edgers/ppa

Also it makes sense to upgrade kernel and graphical stack to HWE of 14.04.2.

It can be done by running:

sudo apt-get install --install-recommends linux-generic-lts-utopic xserver-xorg-lts-utopic libqt5gui5 libgles1-mesa-lts-utopic libgles2-mesa-lts-utopic libgl1-mesa-glx-lts-utopic libgl1-mesa-glx-lts-utopic:i386 libglapi-mesa-lts-utopic:i386 libegl1-mesa-drivers-lts-utopic

Then reboot.

After that try both 346 and 349 drivers. New kernel and stack support newer hardware better.