Wednesday, September 16, 2015

Projecting a Laptop Display to Another Device

From presentations to videos with friends to viewing photo collages, projecting a laptop display to another device is easy and effective.  Connecting a laptop to a television or projector requires only a few steps and can be done in minutes.  The most important part of connecting a laptop to an external display is having the correct connecting cable to go between the two devices.

The correct cable is usually decided by the older device.  The two main cable options are VGA and HDMI cables.  VGA cables, or Video Graphics Array, are an older technology used to connect devices that carry signals in analog format.  VGA cables are familiar because they have been used to connect monitors to desktop computers for years.  One of the most important things to note about VGA cables is that they do not carry audio signals.  This means additional cables are required for sound if the sound from the laptop is not enough.  HDMI cables, or High-Definition Multimedia Device, are newer and carry both video and audio signals in a digital format on a single cable.

       A VGA cable connector                                                       An HDMI cable connector

The type of cable needed to connect two devices depends upon the older device.  Newer devices normally have HDMI ports, while older devices might only have a VGA port available.  If a laptop and a device do not have the same port types available, there are adapters that can be purchased to allow an HDMI cable to plug into VGA ports.  There are also adapters for MAC devices that allow VGA or HDMI cables to plug into lightning ports.

To connect a laptop to an external device, plug the correct cable into the laptop then connect the other end of the cable to either a television, projector or other device.  If the secondary device does not connect automatically, use the media button on the laptop to project the laptop display onto that device.  The media display button toggles between three different settings:

  1. The display on the local laptop
  2. The display on the externally attached device
  3. Both displays at the same time

The media display button is usually an F key and varies between devices but will look similar to the images shown below.  F keys require the Function (Fn) key to be held at the same time to get the desired results of the button.  Some examples of the media display button:

From YouTube videos to photo collages to presentations, connecting to external displays makes everything easier to view.  Regardless of the reason why a laptop is connected to an external display, the process can be accomplished within a few minutes if all the right pieces are available.  Connecting a mix of older and newer devices requires checking for the appropriate VGA or HDMI cable and adapters can be purchased if necessary.  

As always, technology should make our lives easier and this is one example of this!


  1. Fake DVI Dual-Link cables. Dual-Link is a real thing, so don't get confused here; actually, it's one of the best three consumer display interfaces available right now (and its quality depends on the copper more than the standard, which has excellent implications for specific setups). The problem, though, is that a lot of manufacturers are selling "dual-link" cables that don't even have the extra pins wired! They have the dual-link pins, but if you cut the cable open, it's got no wires running between the pins. They're just dummy pins. Technically, the header is "dual-link," but the VGA Cable itself is single-link and won't support higher resolutions as expected.

  2. Good points, DVI does exist, however DVI in my experience is usually not found on laptops or Ultrabooks. This blog post was targeted more towards the laptop side than the projector side but thanks for the comments!

  3. A fiber-optic system is similar to the copper wire system that fiber-optics is replacing. The difference is that fiber-optics use light pulses to transmit information down fiber lines instead of using electronic pulses to transmit information down copper lines. Looking at the components in a fiber-optic chain will give a better understanding of how the system works in conjunction with wire based systems.At one end of the system is a transmitter. This is the place of origin for information coming on to fiber-optic lines. The transmitter accepts coded electronic pulse information coming from copper wire. It then processes and translates that information into equivalently coded light pulses.Think of a VGA Cable in terms of very long cardboard roll (from the inside roll of paper towel) that is coated with a mirror on the inside.If you shine a flashlight in one end you can see light come out at the far end - even if it's been bent around a corner.