Head Mounted Display is worn on the head of a visual output device, the computer generated image is projected on a near-eye display or directly on the retina.
Technology behind Head Mounted Display
Due to the physical proximity of Head Mounted Display units, images appears to be much larger than the free-standing screens and in extreme cases even cover of the entire field is in view of the user. Since the Head Mounted Display followed by a head support all movements of the head of the wearer, user gets the feeling to move inside directly into the computer-generated image landscape. Some Head Mounted Display leaves other visual impressions of the environment and leave the user immersed in a completely virtual reality.
Head Mounted Display can in principle serve as a convenient replacement screen, allowing for example, viewing and editing of video material with extremely large image size. By virtual reality, aspiring pilots and tank drivers and risky medical surgical techniques on the computer so far gives the greatest form of realism. Image can be combined with other systems, the sense of sight and the semi-transparent augmented reality offers the possibility of all kinds of information directly expand into the area, ranging from tourist information to attractions on the direction of instructions on the road.
Types of Head Mounted Display
The main components of a Head Mounted Display is a display unit. The display unit of Head Mounted Display provides the image from a connected data source. This can be a laptop, a pocket computer or stand alone player. Head Mounted Display will forward the image and projects it in front of the eyes. However, the indication for defective vision of the eyes are adapted and corrected.
Head Mounted Display of the first generation were equipped with one eye cathode ray tube.
Today’s Head Mounted Display mostly uses one or two LCD monitors. These are integrated in a pair of glasses of the Head Mounted Display. Displays of this kind in the commercial sector have a resolution of about 320 x 240 pixels and the image size in about a 50-cent coin.
Modern Head Mounted Display are equipped with a virtual retinal display (VRD). This technique projects an image directly onto the retina. Thus a picture emerges, as if the data are floating in front of the eye. Together with a transparent or translucent glasses on the Head Mounted Display, the eye can detect the environment and the representations of the spectacles at the same time. Another advantage is that the image can be scaled and so the whole field of view is utilized. Modern Head Mounted Display are equipped with a screen resolution of 1280 x 1024 pixels available.
Head Mounted Display uses a head tracker that detect the head movement. With the collected data of the head position, the projected image in real time can be changed.