Focus-plus-context screen
Encyclopedia
Display device
A display device is an output device for presentation of information in visual or tactile form...
that consists of one or more high-resolution "focus" displays embedded into a larger low-resolution "context" display. Image content is displayed across all display regions, such that the scaling of the image is preserved, while its resolution varies across the display regions.
The original focus-plus-context screen prototype consisted of an 18"/45cm LCD screen embedded in a 5'/150cm front-projected screen. Alternative designs have been proposed that achieve the mixed-resolution effect by combining two or more projectors with different focal length
Focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light. For an optical system in air, it is the distance over which initially collimated rays are brought to a focus...
s
While the high-resolution area of the original prototype was located at a fixed location, follow-up projects have obtained a movable focus area by using a Tablet PC
Tablet computer
A tablet computer, or simply tablet, is a complete mobile computer, larger than a mobile phone or personal digital assistant, integrated into a flat touch screen and primarily operated by touching the screen...
.
Patrick Baudisch is the inventor of focus-plus-context screens (2000, while at Xerox PARC
Xerox PARC
PARC , formerly Xerox PARC, is a research and co-development company in Palo Alto, California, with a distinguished reputation for its contributions to information technology and hardware systems....
)
Advantages
- Allows users to leverage their foveal and their peripheral vision
- Cheaper to manufacture than a display that is high-resolution across the entire display surface
- Displays entirety and details of large images in a single view. Unlike approaches that combine entirety and details in software (fisheye views), focus-plus-context screens do not introduce distortion.
Disadvantages
- In existing implementations, the focus display is either fixed or moving it is physically demanding