RotoView Theory of Operation
Personal smart media devices
have great computation power and connectivity to provide users with a vast
amount of visual data, including web pages, maps, pictures, spreadsheets and
other information content. The emergence of high-resolution active TFT Liquid
Crystal and OLED displays has vastly increased the number and variety of smart
hand-held devices with information displays. Such devices now include
smartphones, gaming devices and a variety of hand-held computers, GPS based
maps and others.
The display's SIZE will always remain small due to the limitations inherent to
the hand-held device's small form factor. This fact leads to the challenge of
displaying the contents of a large stored virtual display on the device's small
screen. The following pictures illustrates the relations between the virtual
display and the actual device's screen.
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| The relation between
the stored virtual display (left) and the actual hand-held device's display
(right). The yellow bordered area on the virtual display is all the device's
display can show (without image reduction). |
Clearly, smart personal
media device must employ view navigation methods that will enable the user to
scroll the large stored virtual display. Traditionally, this function was done
by keyboards, and in recent years view navigation by touch screen became very
popular. And yet, a major challenge remains - how to enable single-hand
operation of the device. For example, while you can navigate a view using touch
screen with one hand, it becomes awkward when many live links are displayed,
which you can inadvertently activate while scrolling the page with your finger.
The RotoView technology was invented to resolve this problem. It is intended to
complement multi-touch devices, as well as to complement keyboard navigation in
devices like electronic book readers where touch screen glare is not
desired.
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RotoView-enabled devices allow the user to scroll any virtual
display just by tilting the device. This reduces the need for pressing switches
or using your fingers to navigate the display. |
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RotoView's can use any built-in orientation sensor, like
accelerometers, gyroscopes, camera-based tilt sensors and more.
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Our patented RotoView technology controls the
view navigation based on changes in the device tilt and related movements.
RotoView defines two modes of operation: fixed mode; and view navigation mode.
Fixed mode is when RotoView is disengaged and the device view is fixed (or
controlled by other view navigation means, such as buttons and touch-screen).
During navigation mode the hand-held device senses changes in its tilt and
movement to determine the view navigation (or scrolling) along the x and y axes
(up-down, left-right) of the virtural display.
Orientation sensors have been used for many
years in virtual reality systems and in a variety of three-dimensional pointers
and 3D mice. Such sensors include accelerometers, gyroscopes, magnetic sensors,
camera-based orientation sensor, and many more. Typical of these sensors is the
accelerometer. Most smartphones manufactured
today already include an accelerometer and software driver to auto-select
"portrait" or "landscape" display mode. Since we invented
tilt-based view navigation many years before the emergence of the modern smart
phone, we first introduced RotoView technology using our
PC-base evaluation
board. Nowadays, the accelerometer is embedded within the smart media
device and the application designer simply interfaces to it via the operating
system. In fact, RotoView can be quickly implemented within the device's operating
systems and enhance all other applications running on the device.
The user's hand movement
cannot be restricted only to tilt change - all hand movements include some
lateral movements with acceleration components that add to the sensor's
measurements. As a result, precise control of tilt-based view navigation by
accelerometers is not efficient if the system rigidly responds to the sensor
data. Gyroscopes sensors, which are expected to proliferate in smart media
devices in the near future, provide better tilt change detection compared to
the accelerometer since it does not respond to linear movements. Furthermore,
the user often needs to perform a fast and substantial scrolling of the view to
reach the area of interest and then to follow delicately to the final
destination. This is one of the reason for the success of the the
"flick" gesture in today's multi-touch systems. To achieve similar
performance and overcome sensor limitations, RotoView technology employs our
Non-linear Dynamic Response (NLDR) algorithms, to
quickly and intuitively responds to the user's orientation changes. This
creates a closed control loop that alleviates the need for exact linear
relation between the orientation changes and the resulting display navigation.
The NLDR algorithms exhibit the following main features:
- Response curves providing non-linear relation
between the amount of tilt or hand movement and the amount (or rate) of view
navigation.
- Selection of different stored response curves
for use by different applications.
- The response curves may further change
dynamically during the navigation process.
While in Navigation mode, response to the
re-orientations of the device may change dynamically as mentioned above. For
example, at the start of the navigation, the response is fairly coarse to bring
the display to the general area. After a few seconds within Navigation mode,
the response automatically becomes more refined, to allow exact placement of
the display. As a result, RotoView does not require an exact correlation
between orientation changes and actual navigation of the display, which allows
the use of relatively low cost coarse sensors to determine the orientation
changes.
In addition to the use of a switch or touch screen command to activate
Navigation mode, a RotoView implementation may activate Navigation mode by
tapping on the enclosure of the hand held device. Another embodiment activates
the Navigation mode by a specific hand gesture. Both of these activation
options are well suited for single hand operation.
RotoView stores a trail of virtual display navigation states during the view
navigation so that the system can be returned to the fixed mode with any of the
stored states. The trail is used when a hand gesture command to exit navigation
view mode is detected. The personal media display is set to the state just
prior to the start of the movement associated with the gesture.
Similarly, a stored display state of the trail can be selected by the user to
"undo" any inadvertent view navigation that occurs during view
navigation mode.
Please click here to
review additional issues relating to the
user interface experience with RotoView.
Theory of
Operation