Using a distance-sensor
This page describes the patent-pending Xpoint embodiment,
supplementing the Utility Patent, and makes
explicit use of a distance-sensor.
As explained below, the inclusion of the distance-sensor results in a device that allows the user to move about the room
without having to repeat the calibration routine (i.e., marking the corners of the display with the integrated laser).
[00183]
Yet another preferred embodiment results as a variation on a
combination of the preferred embodiments described in paragraphs 114-119 and
paragraphs 120-139, and will be disclosed here with reference to Figs. 3,
11, 12,
24, and 25. It will be understood that, for reasons of clarity, projection
device 40 has not been drawn in Fig. 25. The present embodiment is characterized
by a pointing device 20 that is equipped with at least a distance measuring
device 206, and a coordinate sensing device 201 that may be limited to sensing
orientation. Such a coordinate sensing device 201 may for example rely on an
electronic compass like the HMR3300, on gyroscopes, on combinations of the
above, or on any other suitable technology. It will be assumed that the position
of pointing device 20 does not change substantially while the calibration
procedures described in Figs 3, 11
and 12 are being executed, as indicated in
Fig. 25 by the two near-coinciding instantiations of pointing devices 20. For
purpose of explanation it will therefore be assumed that the origin of
coordinate system x y z and the origin of coordinate system x’ y’ z’ are
coincident, at least while the above-mentioned calibration procedures are
executed. Finally, it will be assumed that one of the axes of the orthogonal
coordinate system x y z is substantially vertical while the other two are
substantially horizontal (the inclusion of a level-sensing device 303 may be
beneficial in this context).
[00184]
The
operation of the present embodiment will now be described with reference to
Figs. 3, 11, and
12. The process elements in Fig. 3
will be identical to the
ones described in the
first embodiment, resulting in similar assumptions
regarding the shape of interaction region 71 (and interaction structure 72) and
possibly orientation and position of interaction structure 72.
[00185]
With
reference to Fig.
11, program flow now continues at 120a. Program elements
120a-120h are shown to be similar to program elements 90a-90m (Fig. 4), except
that only point CA, set A and counter a are considered. That is to say, in the
present embodiment it is no longer necessary to determine the second point CB
and associated repositioning of pointing device 20 during the calibration
procedure, since the position of pointing device 20 is assumed not to change
substantially from the origin of coordinate system x y z during execution of the
steps considered.
[00186]
After
program element 120h, program flow continues with program elements outlined in
Fig. 12. Referring to Fig. 12, program elements 130a-130g are seen to be similar
to steps 100a-100p of Fig. 5. Comparing program element 130f with program
element 100f (Fig. 5), it can be seen that at 130f the program also stores
information on the point-of-aim-distance
(not shown in Fig.
25, but shown as 211 in Fig.
2) between the origin of the
x’ y’ z’ coordinate system and point C(p). Comparing elements 130g and
100p (Fig. 5), it can seen that these point-of-aim-distances (211 in Fig.
2) are
also used in determining the 3D coordinates of the points in set P.
[00187]
With
complete information on the 3D coordinates of the points in set P, it is then
possible to construct a 3D description of interaction structure 72 (see Fig.
25). Therefore, program elements
110a-110k as described earlier with reference to Fig. 6 may also be followed in
the present embodiment.
[00188]
As in
previously described embodiments, the above outlined embodiment may be
satisfactorily used as a direct-pointing system if the position of pointing
device 20 does not change substantially from the origin of coordinate system x y
z. When the user moves to a different part of the room, the position of pointing
device 20 will, by assumption, be unknown (since coordinate sensing device 201
was assumed to only be capable of sensing orientation). This position then needs
to be reestablished in order to be able to execute steps like 110f and 110h (see
Fig. 6), which allow the system to be used for direct-pointing cursor control.
[00189]
In order
to reestablish the position of pointing device 20 the user may be required to
direct pointing line 21 to substantially pass through a point of which the 3D
coordinates are known in coordinate system x y z. In doing so, the user may but
need not be assisted by light-beam projection device 202. This point could, for
example, be a corner point or any other well-defined point of interaction
structure 72 (which, by assumption, coincides with interaction region 71)
Advantageously, it could be the last position that projected cursor 701 (see
Fig.
25) was directed to, as will be appreciated by those skilled in the art.
After all, the 3D characteristics of interaction structure 72 (and interaction
region 71) are known, as is the position of computer cursor 501; the inverse of
map M can then easily be used to compute the 3D characteristics of projected
cursor 701. It will also be apparent to those skilled in the art that
measurements of the orientation of pointing line 21 and point-of-aim-distance
211 will then constitute enough information to calculate the position of
pointing device 20 in coordinate system x y z. With the position of pointing
device 20 re-established, the present embodiment can again successfully be used
to control the computer cursor in a direct-pointing manner. This will remain to
be the case as long as the position of pointing device 20 does not stray far
from the recently re-established position.
[00190]
The
applicant recognizes that the action of directing pointing line 21 through the
above-mentioned well-defined point (while measuring point-of-aim-distance 211
and orientation of pointing device 20) may result in a pointing line 21 not perfectly
passing through this point, especially if the user is not aided by
light-beam projection means 202. Indeed, any errors made during this action will
result in similar mismatches between subsequently calculated points-of-aim and
true points-of-aim of pointing device 20. These mismatches may not be too
apparent to the user though since, presumably, the user was not capable of
discerning such a mismatch when attempting to direct pointing line 21 through
the above mentioned well-defined point, as will be appreciated by those skilled
in the art. Consequently, the present embodiment may still afford the user the
feeling of direct-pointing cursor control under such circumstances.
[00191]
Sensors
capable of sensing position may but need not be added to the coordinate sensing
device 201 of the current embodiment. Indeed, even if these sensors were only
capable of maintaining positional accuracy over a limited period of time (e.g.:
sensors based on accelerometer technologies), their inclusion could still be
advantageous. For example, such sensors may be employed to accurately track the
position of pointing device 20 over the relatively short period of time that
starts when the user directs pointing line 21 through the above-mentioned
well-defined point (whilst measuring point-of-aim-distance 211 and orientation
of pointing device 20), and ends when the user indicates his or her desire to
stop direct-pointing cursor control. This way, direct-pointing cursor control
can still be maintained even if the position of pointing device 20 strays
relatively far from the position it was in at the start of the above-mentioned
period of time, as will be evident to those skilled in the art. In a similar
way, such position sensors may also be beneficial during the (relatively short)
calibration procedures aimed at establishing the 3D characteristics of
interaction structure 72 (and interaction region 71), and can help to reduce
errors that are due to a violation of the assumption that the position of
pointing device 20 remains constant.
[00192]
Thus,
methods and means are disclosed that afford a compact system for interacting
with a presentation in a direct-pointing manner, whilst leaving the presenter
free to move about the presentation venue. This system, moreover, obviates the
need for a base-station 30 that embodies a coordinate system x y z, and for a
coordinate sensing device 201 capable of continuously tracking positional
coordinates of pointing device 20 in this coordinate system.
[00193]
It will
be obvious that elements of the various disclosed embodiments can advantageously
be combined. In particular, combining the embodiments described in paragraphs
177-182 and paragraphs 183-192 will result in a system that may calibrate itself
automatically, and leaves the presenter free to move about the presentation
venue whilst engaging in direct-pointing interaction with the display. Moreover,
the resulting system obviates the need for a base-station 30 that embodies a
coordinate system x y z, and for a coordinate sensing device 201 capable of
continuously tracking positional coordinates. As such, this system will be seen
to be highly flexible, relatively inexpensive to manufacture, and extremely
user-friendly.
