U.S. patent application number 13/367090 was filed with the patent office on 2012-05-31 for apparatus for determining the position of a device.
This patent application is currently assigned to Marvell International Technology Ltd.. Invention is credited to James D. Bledsoe, James Mealy, Asher Simmons.
Application Number | 20120136620 13/367090 |
Document ID | / |
Family ID | 39733760 |
Filed Date | 2012-05-31 |
United States Patent
Application |
20120136620 |
Kind Code |
A1 |
Mealy; James ; et
al. |
May 31, 2012 |
APPARATUS FOR DETERMINING THE POSITION OF A DEVICE
Abstract
An apparatus and method are disclosed for use in a device, such
as a handheld printer or scanner, having functionality that
requires information of its position relative to an origin and
initial orientation. The module includes two sensors to generate
movement data indicative of movement direction and orientation
changes of the device. The location and orientation of the device
relative to the origin and initial orientation is derived based on
the movement data. A handheld printer or scanner implementing the
device may thus be moved in different directions across a media to
print or scan images, text, or other objects.
Inventors: |
Mealy; James; (Corvallis,
OR) ; Bledsoe; James D.; (Albany, OR) ;
Simmons; Asher; (Corvallis, OR) |
Assignee: |
Marvell International Technology
Ltd.
Hamilton
BM
|
Family ID: |
39733760 |
Appl. No.: |
13/367090 |
Filed: |
February 6, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12041307 |
Mar 3, 2008 |
8121809 |
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13367090 |
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60892693 |
Mar 2, 2007 |
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Current U.S.
Class: |
702/141 ;
702/150 |
Current CPC
Class: |
G01B 21/00 20130101;
B41J 3/36 20130101; B41J 29/393 20130101 |
Class at
Publication: |
702/141 ;
702/150 |
International
Class: |
G06F 15/00 20060101
G06F015/00; G01P 15/18 20060101 G01P015/18 |
Claims
1. An apparatus comprising: a module configured to generate
movement data in response to movement of a handheld device, the
movement data indicative of location changes and orientation
changes of the handheld device; and a processor configured to
receive the movement data and determine location and orientation
data indicative of a position of the handheld device relative to a
given location and a given orientation of the handheld device.
2. The apparatus of claim 1, further comprising: a spatial position
module configured to identify when the handheld device loses
physical contact with a medium.
3. The apparatus of claim 2, wherein the processor is configured to
select a spatial tracking mode when the handheld device loses
physical contact with the medium.
4. The apparatus of claim 3, further comprising: an inertial motion
sensor configured to generate three-dimensional coordinates for the
spatial tracking mode.
5. The apparatus of claim 3, wherein the processor is a first
processor, the apparatus further comprising: a second processor,
wherein the first processor is adapted to communicate the location
and orientation data to the second processor; and a print
mechanism, wherein the second processor is configured to determine
print data based on the location and orientation data, and to
communicate the print data to the print mechanism.
6. The apparatus of claim 5, further comprising: an imaging
mechanism configured to generate image signals, wherein the second
processor is configured to receive the image signals and generate
image data based on the location and orientation data.
7. The apparatus of claim 5, further comprising: a wireless
communication module in communication with the second processor,
wherein the wireless communication module is adapted to receive
image data from a host device and communicate the image data to the
second processor.
8. The apparatus of claim 7, wherein the image data is a
bitmap.
9. The apparatus of claim 7, wherein the wireless communication
module and the host device comprise a wireless local area
network.
10. The apparatus of claim 3, wherein the module comprises first
and second motion sensors and is configured to communicate the
movement data to the processor in response to movement of the first
and second motion sensors.
11. A tangible computer readable storage medium having processor
executable instructions configured to: receive movement data
indicative of location changes and orientation changes of a
handheld device, and determine location and orientation data
indicative of a position of the handheld device relative to a given
location and given orientation of the handheld device.
12. The tangible computer readable storage medium of claim 11, the
instructions further configured to: identify when the handheld
device loses physical contact with a medium; and select a spatial
tracking mode when the device loses physical contact with the
medium.
13. The tangible computer readable storage medium of claim 12, the
instructions further configured to: receive image data from a
wireless communication module; determine print data based on the
image data and the location and orientation data; and communicate
the print data to a print mechanism.
14. The tangible computer readable storage medium of claim 12, the
instructions further configured to: receive image signals from an
imaging mechanism; and generate image data based on the image
signals and the location and orientation data.
15. An apparatus for use with a device, the apparatus comprising: a
first motion sensor configured to generate a first motion signal in
response to movement of the device; a second motion sensor
configured to generate a second motion signal in response to
movement of the device; a module configured to generate movement
data based on the first motion signal and the second motion signal;
and a processor configured to determine a location and an
orientation of the device based on the movement data.
16. The apparatus of claim 15, further comprising: a spatial
position module configured to identify when the device loses
physical contact with a medium.
17. The apparatus of claim 16, wherein the first processor is
configured to select a spatial tracking mode when the device loses
physical contact with the medium.
18. The apparatus of claim 17, further comprising: an inertial
motion sensor configured to generate three-dimensional coordinates
for the spatial tracking mode.
19. The apparatus of claim 18, wherein the processor is a first
processor, the apparatus further comprising: a second processor,
wherein the first processor is adapted to communicate the location
and orientation data to the second processor; and a print
mechanism, wherein the second processor is configured to determine
print data based on the location and orientation data, and
communicate the print data to the print mechanism.
20. The apparatus of claim 18, wherein the first motion sensor and
the second motion sensor comprise respective light-emitting diode
and complementary metal-oxide semiconductor pairs.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/892,693, filed on Mar. 2, 2007, which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to the field of position
sensing, and more particularly to an apparatus and method for
determining the absolute position, including the location and
orientation, of a device with respect to an origin as the device is
moved.
[0004] 2. Related Art
[0005] Many devices rely on positioning data to operate. For
example, an inkjet printer relies on positioning data and the
mechanics of a print assembly to ensure that thousands of ink dots
are placed at precise locations on a media by the nozzles of a
print head. Similarly, a scanner relies on positioning data, stable
media placement, and a stabilizer bar to move a scan head along the
media with precision. The printer and the scanner rely upon the
positioning data to control the movement of components that, by
design, are mechanically and precisely restricted or confined in
direction and movement. Consequently, accurate imaging is
achieved.
[0006] A stand alone device such as a desktop printer is large
enough to include the components required to move the media and
print head relative to one another with precision as an image or
object is rendered on the media. Likewise, a desktop scanner is
large enough to include the components that steadily and precisely
move the stabilizer bar along the media. However, such stabilizing
and positioning components are usually too large for use in smaller
devices. For example, handheld scanners are not large enough to
incorporate the components that desktop scanners have to generate
accurate image data. Rather, handheld scanners rely on human motor
skills to steadily move the stabilizer bar (or some other device
that supports the scan head) across the media. Human motor skills
are far less precise than the components implemented in desktop
devices and the quality of digital images that are obtained with
handheld scanners is markedly inferior to that of desktop scanners.
An improvement in the operation of handheld devices is
desirable.
BRIEF SUMMARY
[0007] The following embodiments relate to systems and methods for
generating position data for a device. The position data is
indicative of the device's position as it is moved and includes the
location and orientation of the device with respect to an origin.
The position data may be used by the device to perform device
functions. For example, the device may be a handheld printer that
controls a print head based on the position data to accurately
dispense ink on a print media.
[0008] In a preferred embodiment, a module has two motion sensors
to generate motion signals as a device is moved. The module
generates movement data in response to the motion signals. The
movement data is indicative of location changes and orientation
changes of at least two points on the device. The module
communicates the movement data to a processor that determines
location and orientation data indicative of the device's position
relative to an origin. The processor may communicate the location
and orientation data to a device processor for use in executing
device functions. The motion sensors may be optical motion sensors,
track-ball motion sensors, laser motion sensors, inertial motion
sensors, or any other type of motion sensor.
[0009] In one implementation, the device is a handheld printer
having a wireless communication module to receive image data from a
host device. The wireless communication module communicates the
image data to the processor, which determines print data based on
the image data and the location and orientation data. The print
data controls a print mechanism for dispensing ink, dye, or other
pigment as the handheld printer is moved over a print media.
[0010] In a second implementation, the device is a handheld scanner
having an imaging mechanism to generate image signals. A device
processor receives the image signals and generates image data based
on the image signals and the location and orientation data.
[0011] In a second embodiment, a computer readable storage medium
has processor executable instructions to receive movement data
indicative of location changes and orientation changes of a device
and determine location and orientation data indicative of a
position of the device relative to a first location and first
orientation of the device. The computer readable storage medium may
also have processor executable instructions to communicate the
location and orientation data to a device processor. If the device
is a printer, the computer readable storage medium may have
processor executable instructions to determine print data based on
image data and the location and orientation data, and communicate
the print data to a print mechanism. If the device is a scanner,
the computer readable storage medium may have processor executable
instructions to receive image signals from an imaging mechanism,
and generate image data based on the image signals and the location
and orientation data.
[0012] Other systems, methods, and features of the invention will
be, or will become, apparent to one with skill in the art upon
examination of the following figures and detailed description. It
is intended that all such additional systems, methods, features and
advantages be included within this description, be within the scope
of the invention, and be protected by the following claims.
[0013] The preferred embodiments will now be described with
reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows acts for determining the location and
orientation of a device with reference to an initial position as
the device is moved, in accord with an embodiment of the
invention;
[0015] FIG. 2 is a block diagram of an embodiment of a position
module for determining the location and orientation of a device
with reference to an initial position;
[0016] FIG. 3 is a block diagram of an embodiment of a device that
includes the position module of FIG. 2;
[0017] FIG. 4 is an illustration of the printing side of a handheld
printer that determines its location and orientation with reference
to an initial position as it is moved across a media; and
[0018] FIGS. 5(a) to 5(e) illustrate the functionality of the
handheld printer of FIG. 4.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0019] The disclosure can be better understood with reference to
the following drawings and description. The components in the
figures are not necessarily to scale, emphasis instead being placed
upon illustrating the principles of the invention. Moreover, in the
figures, like referenced numerals designate corresponding parts or
elements throughout the different views.
[0020] The embodiments below relate to a position module for use in
a device having functionality that requires information about its
position relative to an origin and initial orientation at the
origin as the device is moved. The position module is incorporated
into the device and includes a processor and a movement module
having two sensors. When the device is moved, both sensors sense
device movement and generate movement signals. The movement module
generates movement data based on the movement signals. The movement
data is indicative of movement direction and distance of each
respective sensor, and hence any part of the device. Based on the
movement data, the processor determines the location and
orientation of the device relative to the origin and initial
orientation. The position module may be implemented in devices such
as handheld printers and scanners to maintain image alignment as
the device is swept over a print media for printing or scanning
operations, as examples.
[0021] FIG. 1 shows acts 100 for determining the position of a
device with reference to an initial position as the device is
moved. The position of the device is defined by the device's
location and orientation. The location of the device may be
represented by any point defined within or on the device, such as a
center-point. Alternatively, the location of the device may be
defined by any point outside the device having a set geometrical
relationship to the device. The orientation of the device is
defined as an angle relative to an initial orientation.
[0022] In one embodiment, the device is set at a position
designated as the initial position or "origin" of the device. The
origin includes an initial location and initial orientation of the
device before it is moved (Act 102). The act of designating an
initial location and an initial orientation of the device may be
referred to as "zeroing the origin." The initial location and
initial orientation may be defined within any two or three
dimensional coordinate system. In one implementation, the device is
a rectangular handheld printer set at an origin on a print media,
such as the top-left corner of a sheet of paper, with the top edge
of the handheld printer aligned with the top edge of the sheet of
paper and the left edge of the handheld printer aligned with the
left edge of the sheet of paper.
[0023] As the device is moved (whether by human hand, machine, or
self propulsion) movement data is generated to track location
changes and orientation changes of the device (Act 104). The
movement data may be generated by any component, module, or any
mechanism that generates data indicative of movement.
[0024] FIG. 2 shows an embodiment of a position module 200 that
generates movement data. The position module 200 includes a
movement module 202 and a processor 208. The movement module 202
includes two motion sensors 204 and 206. The motion sensors 204,
206 may be optical motion sensors such as light-emitting diode
(LED) and complementary medal-oxide semiconductor (CMOS) sensor
pairs. Each CMOS sensor captures hundreds of images per second as
is moves. The movement module 202 includes a movement module
processor 210 to receive the images from the motion sensors 204,
206. The movement module processor 210 detects patterns in each
image and compares the patterns in successive images to determine
movement direction and distance of each CMOS sensor. The movement
module processor 210 may be any hardware, software, or firmware
based processor. In alternate versions, the motion sensors 204, 206
may be track-ball motion sensors, laser motion sensors, inertial
motion sensors, or other type of motion sensors that generate
movement signals. In other versions, the movement module 202 may be
a mapping type module that detects preprinted infrared (IR) or
preprinted visible markings from a print media and correlates them
to a programmed map of the markings. Other types of movement
modules are contemplated and may be implemented with the position
module 200.
[0025] Direction and distance data is generated for both motion
sensors 204, 206 as the device moves. For example, as motion sensor
204 moves from point A to point B and motion sensor 206 moves from
point M to point N, direction and distance data is generated by the
movement module 202 for each sensor 204, 206. The location of
motion sensor 204 with respect to point A and the location of
motion sensor 206 with respect to point M is determined by the
movement module 202 based on the direction and distance data
generated for each respective sensor 204, 206. When motion sensor
204 next moves from point B to point C, the movement module 202
determines the location of motion sensor 204 with respect to point
B. Likewise, when motion sensor 206 moves from point N to point O,
the movement module 202 determines the location of motion sensor
206 with respect to point N. The movement module 202 generates
movement data indicative of the movement of each motion sensor 204,
206 from point-to-point and communicates the movement data to the
processor 208.
[0026] The processor 208 determines the position of the device with
respect to the origin (the initial location and initial orientation
of the device) by cumulating the movement data received from the
movement module 202 (Act 106). The position of the device
determined by the processor 208 includes both the location and
orientation of the device with respect to the origin and may be
referred to as the "absolute position" of the device.
[0027] The location of the device (or any point, line, or area of
the device) is determined by cumulating the movement data, starting
from the origin. The orientation of the device is defined as an
angle between two lines: the first line is defined by the locations
of the two motion sensors when the device is at the origin; the
second line is defined by the locations of the two motion sensors
when the device is at its respective location. As movement data
continues to be received from the movement module 202 as the device
moves, the processor 208 continues to update the absolute position
of the device. The absolute position of the device may be
communicated as location and orientation data to a device processor
for use in operating the device (Act 108).
[0028] FIG. 3 is a block diagram of an embodiment of a device 300
that includes a position module 306. The device 300 may be a
handheld printer, handheld scanner, other handheld device, or any
mobile device.
[0029] The device 300 includes a housing 302 and device components
304, including a device processor 314 for executing device
functions. The device 300 may also include a data bus 308, a power
module 310, and a wireless communication module 312 to communicate
with a host (not shown) or other device.
[0030] If the device 300 is a handheld printer, the wireless
communication module 312 receives image data, such as a bitmap,
from the host and communicates the image data to the device
processor 314. The device processor 314 determines print data based
on the image data and the location and orientation data received
from the position module, and communicates the print data to a
print mechanism. The print mechanism renders an image or text on a
print media.
[0031] If the device 300 is a handheld scanner, the device
processor 314 receives image signals from an imaging mechanism and
determines digital image data based on the image signals and the
location and orientation data received from the position module.
The device processor 314 communicates the digital image data to the
wireless communication module 312, which communicates the image
data to the host. The host may be a desktop or laptop computer, or
other device that communicates (sends/receives) image data. In
alternate embodiments, the host may send/receive other types of
data pertinent to the function of the device components 304. The
wireless communication module 312 and the host may comprise a
network such as a wireless local area network (WLAN), as an
example.
[0032] As discussed above, the device 302 may be a handheld
printer. FIG. 4 is an illustration of an embodiment of the printing
side (underside) 402 of a handheld printer 400 that determines its
location and orientation with reference to an initial position as
it is moved across a media. The handheld printer 400 has two motion
sensors 404(a) and 404(b) and a print head 406. The handheld
printer 400 receives print data from a host. For rendering an image
on a media, the handheld printer 400 is moved or swept across the
surface of the media. If the handheld printer 400 is smaller than
the media, it may need to be swept across the media several times
to render a complete image.
[0033] As the handheld printer 400 is swept across the media, the
motion sensors 404(a) and 404(b) generate motion signals for
determining the absolute position of the print head 406. The print
head 406 dispenses print from its nozzles based on the absolute
position of the handheld printer 400.
[0034] FIGS. 5(a)-5(e) illustrate the functionality of a handheld
printer 400 that dispenses ink (or any pigment or dye) based on its
absolute position as it is swept across a media. FIG. 5(a)
illustrates, in picture format, a digital image of an object 502.
The digital image is communicated to the handheld printer 504 shown
in FIG. 5(b). The handheld printer 504 is set at an origin on a
print media 506. FIG. 5(c) illustrates with directional arrows the
direction of movement and rotation of the handheld printer 504 as
it is swept across the media 506. FIG. 5(d) illustrates that even
though the orientation and alignment of the handheld printer 504
changes as it sweeps across the media 506, the printed object is
aligned on the print media 506 as it was in the digital image.
Proper alignment was achieved by controlling the print dispenser
based on the determined absolute position of the handheld printer
504. In contrast, FIG. 5(e) illustrates the result of a handheld
printer 508 that does not determine its absolute position.
[0035] The methods and systems discussed above for determining the
position of a device may also include methods and systems for
determining the spatial position of the device. As used herein, the
"spatial position" refers to the three-dimensional position and
orientation of the device. For example, the position module 200 may
include a spatial position module (not shown) to determine three
translational coordinates (x-y-z) and three angular (yaw, pitch,
and roll) parameters of the device. The translational coordinates
and the angular parameters may be referred to collectively as the
"six degrees of freedom". The spatial position module may determine
the six degrees of freedom based on data received from an inertial
motion sensor, such as an accelerometer or gyrometer, as an
example. The inertial motion sensor may be included in the position
module 200 or may be part of the device.
[0036] The spatial position module may provide a first set of data
to the position module 200 for determining the "macroscopic"
position and orientation of the device, and the movement module 202
may provide a second set of data to the position module 200 for
determining more detailed position and orientation data. For
example, if the device is a handheld printer, the spatial position
module may provide a first set of data to the position module 200
for determining whether the handheld printer is in contact with the
print media and/or its location and orientation. If it is
determined that the handheld printer is in contact with the print
media, the movement module 202 may provide a second, more detailed
set of position and orientation data, as discussed above, for use
to accurately print an image.
[0037] The spatial position module may also provide data for
determining the location and orientation of the handheld printer on
the print media in the event the handheld printer loses and regains
physical contact with the print media. For example, a user may
accidentally or intentionally lift the handheld printer off the
print media. The position module 200, in conjunction with the
spatial position module, does not depend upon contact with the
print media to maintain spatial position and orientation data. If
the position module 200 detects that the handheld printer has been
removed from the print media, it may switch to a "spatial tracking
mode". The position module 200 may determine that the handheld
printer has been removed from the print media based on a signal (or
lack of a signal) received from the motion sensors 204 and 206, as
an example. In spatial tracking mode, the position module 200
utilizes data received from the spatial position module to
determine the location and orientation of the device. Once the
position module 200 determines that the handheld printer is again
in contact with the print media (based on a signal or lack of
signal received from the motion sensors 204 and 206), it may switch
to a "detailed tracking mode" and rely on data received from the
movement module 202 for determining the position and orientation of
the device for printing.
[0038] All of the discussion above, regardless of the particular
implementation being described, is exemplary in nature, rather than
limiting. Although specific components of the position module 200
are described, methods, systems, and articles of manufacture
consistent with the position module 200 may include additional or
different components. For example, components of the position
module 200, movement module 202, and/or processor 208 may be
implemented by one or more of: control logic, hardware, a
microprocessor, microcontroller, application specific integrated
circuit (ASIC), discrete logic, or a combination of circuits and/or
logic. Further, although selected aspects, features, or components
of the implementations are depicted as hardware or software, all or
part of the systems and methods consistent with the position module
200 may be stored on, distributed across, or read from
machine-readable media, for example, secondary storage devices such
as hard disks, floppy disks, and CD-ROMs; a signal received from a
network; or other forms of ROM or RAM either currently known or
later developed. Any act or combination of acts may be stored as
instructions in computer readable storage medium. Memories may be
DRAM, SRAM, Flash or any other type of memory. Programs may be
parts of a single program, separate programs, or distributed across
several memories and processors.
[0039] The processing capability of the system may be distributed
among multiple system components, such as among multiple processors
and memories, optionally including multiple distributed processing
systems. Parameters, databases, and other data structures may be
separately stored and managed, may be incorporated into a single
memory or database, may be logically and physically organized in
many different ways, and may implemented in many ways, including
data structures such as linked lists, hash tables, or implicit
storage mechanisms. Programs and rule sets may be parts of a single
program or rule set, separate programs or rule sets, or distributed
across several memories and processors.
[0040] It is intended that the foregoing detailed description be
understood as an illustration of selected forms that the invention
can take and not as a definition of the invention. It is only the
following claims, including all equivalents, that are intended to
define the scope of this invention.
* * * * *