U.S. patent application number 12/634872 was filed with the patent office on 2010-04-15 for light assisted keyboard for mobile communication device.
This patent application is currently assigned to RESEARCH IN MOTION LIMITED. Invention is credited to Jacek S. IDZIK, Robert J. LOWLES.
Application Number | 20100090957 12/634872 |
Document ID | / |
Family ID | 38052522 |
Filed Date | 2010-04-15 |
United States Patent
Application |
20100090957 |
Kind Code |
A1 |
IDZIK; Jacek S. ; et
al. |
April 15, 2010 |
LIGHT ASSISTED KEYBOARD FOR MOBILE COMMUNICATION DEVICE
Abstract
A mobile communication device having a keyboard with a set of
keys representing alpha-numeric characters, the keyboard comprising
a light source, located within said mobile communication device;
for providing a light; a set of sensors, associated with said keys,
for sensing an amount of said light in a vicinity of each of said
set of sensors, to determine which of said set of keys has been
selected; and a transparent flat cover, overlying said set of
sensors, displaying said set of alpha-numeric characters, for
associating said set of alpha-numeric characters with said set of
sensors.
Inventors: |
IDZIK; Jacek S.;
(Kenilworth, CA) ; LOWLES; Robert J.; (Waterloo,
CA) |
Correspondence
Address: |
Borden Ladner Gervais LLP
1100-100 Queen Street
Ottawa
ON
K1P 1J9
CA
|
Assignee: |
RESEARCH IN MOTION LIMITED
Waterloo
CA
|
Family ID: |
38052522 |
Appl. No.: |
12/634872 |
Filed: |
December 10, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11281490 |
Nov 18, 2005 |
7655901 |
|
|
12634872 |
|
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Current U.S.
Class: |
345/168 ;
345/169 |
Current CPC
Class: |
G06F 3/0426 20130101;
G06F 3/0202 20130101 |
Class at
Publication: |
345/168 ;
345/169 |
International
Class: |
G06F 3/02 20060101
G06F003/02 |
Claims
1. A method for a handheld electronic device including a keyboard
have a plurality of keys, the method comprising: transmitting a
light through at least one light pipe housing a plurality of
sensors, each of the plurality of sensors in a one-to-one
relationship with a corresponding key on the keyboard; determining
a key selection by comparing a measured amount of light surrounding
one of the plurality of sensors with a threshold value;
transmitting a signal when one of the plurality of sensors has
determined that the measured amount of light exceeds the threshold
value; and storing the key selection in a memory of the device.
2. The method of claim 1 further comprising: modulating said light
before determining the key selection.
3. The method of claim 2 wherein determining the key selection
comprises: filtering said modulated light from ambient light
surrounding each of said plurality of sensors; measuring said
amount of filtered light sensed by each of said plurality of
sensors; and comparing said measured value with the threshold
value.
4. The method of claim 1 further comprising: interrupting
applications executing on the device by entering an interrupt table
before storing the key selection.
5. The method of claim 4 further comprising: exiting said interrupt
table.
6. The method of claim 1 further comprising: providing a tactile
response to a user when one of the keys is selected.
7. A method for a handheld electronic device including a keyboard
having a plurality of keys, the method comprising: scanning a
plurality of sensors via a scanning module, each of the plurality
of sensors in a one-to-one relationship with a corresponding key on
the keyboard; determining if one of the plurality of sensors has
sensed the presence of an object; if the object has been sensed,
determining the corresponding key that has been pressed, and
storing the key that was pressed in a memory of the device;
otherwisecontinue scanning.
8. The method of claim 7 further comprising: transmitting a light
through at least one light pipe housing the plurality of
sensors.
9. The method of claim 8 further comprising: determining that one
of the plurality of sensors has sensed the object by comparing a
measured amount of light surrounding one of the plurality of
sensors with a threshold value; and transmitting a signal when one
of the plurality of sensors has determined that the measured amount
of light passes the threshold value.
10. The method of claim 8 further comprising: modulating said light
before determining if one of the sensors has sensed the presence of
the object.
11. The method of claim 10 wherein determining if one of the
sensors has sensed the presence of an object comprises: filtering
said modulated light from ambient light surrounding each of said
plurality of sensors; measuring said amount of filtered light
sensed by each of said plurality of sensors; and comparing said
measured amount with a threshold value.
12. The method of claim 7 further comprising: interrupting
applications executing on the device by entering an interrupt table
before storing the key in the memory.
13. The method of claim 12 further comprising: exiting said
interrupt table.
14. The method of claim 7 further comprising: providing a tactile
response to a user when one of the keys is selected.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/281,490, filed Nov. 18, 2005, which is
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates generally to mobile communication
devices. More particularly, the invention relates to a keyboard for
use with a mobile communication device.
BACKGROUND OF THE INVENTION
[0003] The use of mobile communication devices is growing steadily
as technology improves. Many individuals now own and use mobile
communication devices on a daily basis. These mobile communication
devices are typically easy to use and portable. However, there is a
push to develop lighter mobile communication devices so that users
are not weighed down when carrying their device. This is especially
important when a user attaches the mobile communication device to
their belt, or puts it in their pocket, or purse.
[0004] In some prior art devices, the weight of the keyboard/keypad
is a large percentage of the overall weight of the device due to
the many switches and parts which form the keyboard/keypad. These
switches and parts, also increase the overall thickness of the
mobile communication device which detracts from its portability.
Furthermore, the cost to manufacture and implement the set of
electrical/mechanical switches and parts is quite expensive and
complicated.
[0005] The long term reliability of mechanical switches in the
keyboard/keypad, is quite problematic as the switches are not
dependable and generally require constant repair. Moreover, since
keyboards/keypads in mobile communication devices are generally not
sealed, dirt, dust, liquids, moisture and ESD (electro-static
discharge) may enter the mobile communication device which causes
the switches to provide intermittent input of data and
commands.
[0006] It is, therefore, desirable to provide a novel
keyboard/keypad for a mobile communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Embodiments of the invention will now be described, by way
of example only, with reference to the attached FIGS., wherein:
[0008] FIG. 1a is a schematic diagram of a prior art mobile
communication device;
[0009] FIG. 1b is a schematic diagram of a first embodiment of a
keyboard installed in a mobile communication device;
[0010] FIG. 2 is a schematic diagram of a portion of a
keyboard;
[0011] FIG. 3 is a schematic diagram of light travelling in the
keyboard;
[0012] FIG. 4a is a flowchart of a first embodiment of a method of
using the keyboard of FIG. 2; and
[0013] FIG. 4b is a flowchart of a second embodiment of a method of
using the keyboard of FIG. 2.
DETAILED DESCRIPTION
[0014] Generally, the invention provides a keyboard/keypad for a
mobile communication device. As the terms keyboard and keypad are
typically interchangeable when discussing a mobile communication
device in this application, the term keyboard will be used to
describe both a keyboard and/or a keypad in the following
description.
[0015] Turning to FIG. 1a, a schematic diagram of a prior art
mobile communication device is shown. The mobile communication
device 10 comprises a display area 12, a keyboard area 14 for
receiving a keyboard, a power button 16, a thumbwheel 18 and a
communication port 20. The communication device 10 further
comprises an indicator lamp 22 which indicates when a new message
is received by the device 10. The functionality of these parts will
be well known to one skilled in the art. The keyboard area 14
typically includes a plurality of individual keys representing
alpha-numeric characters.
[0016] Turning to FIG. 1b, a schematic diagram of a mobile
communication device, or handheld electronic device, comprising a
light source keyboard 23 is shown.
[0017] In this embodiment, keyboard lettering 24, outlining
alphabetic or alphanumeric keys 25, is provided on a transparent
sheet 26 which lies over the keyboard area 14, sealing the keyboard
area so that foreign objects, such as dust, dirt or ESD, may not
enter the mobile communication device 10. The keyboard lettering 24
is printed on the top surface of the transparent sheet 26 to
simulate the presence of a keyboard. In use, a user simply presses,
or places their finger over, one of the keys 25 in order to
activate the keys as would be required when typing on a keyboard.
It will be understood that the design or look of the keyboard is
determined by the designer and that various keyboard patterns may
be contemplated. The operation of the keyboard is not affected by
the different keyboard designs or layouts such as a QWERTY, QWERTZ,
AZERTY, QZERTY or other language keyboards.
[0018] FIG. 2 provides a schematic view of a keyboard within the
mobile communication. The mobile communication device 10 further
comprises a light source 42, preferably an infra-red light source,
which provides the necessary light for operation of the keyboard
(as will be described in more detail below) along with a set of
infra-red sensors 30, each associated with one of the keys 25 of
the keyboard and a piezo-transducer 32 which is associated with the
set of infra-red sensors 30 to provide a tactile response to the
user when they press the key. By having only a single transducer,
this assists in decreasing the size and weight of the device and
helps the simplicity of the internal set up of the device.
[0019] Each of the sensors 30 includes a corresponding filter 31,
preferably a bandpass filter, which assists in sensing the light
from the light source 42. Each bandpass filter 31 is preferably
separate from, but associated and in communication, with one of the
set of sensors 30. However, the bandpass filter 31 and the sensor
30 may also be provided as a sensor and bandpass filter
combination. In the preferred embodiment, by using a bandpass
filter, only selected frequencies of the infra-red light are sensed
by the sensors 30 and ambient light does not interfere with the
readings of the sensors 30.
[0020] Each of the rows of sensors are located in a light pipe 44
which receives the light from the light source 42 and directs the
light towards each of the sensors 30 which are preferably connected
to, and in communication with, a processor 34 (within the mobile
communication device 10) which processes the keys which are being
pressed. The processor 34 preferably comprises an interrupt module
36, a scanning module 38 and a memory 40.
[0021] As shown in FIG. 3, in operation, infra-red light from the
light source 42 is transmitted along the light pipe 44 and is
reflected off the light pipe 44 by bouncing off the bottom of the
keyboard (cover 26) and the borders of the keys until the light
reaches an opening 46 (which represent the keys 25 of the keyboard
23).
[0022] The sensor 30 located underneath each of the openings sense
the amount of infra-red light in its immediate vicinity as the
ambient light is filtered out by the bandpass filters 31. When
there is no finger of object covering the opening, the sensor 30
only senses an expected, or default, value of light and therefore
concludes that the key associated with the sensor 30 has not been
selected. It will be understood that each of the sensors has a
threshold infra-red light value (representing the expected value)
but once this threshold is passed (indicating the presence of a
finger), the sensor transmits a signal, such as an interrupt
signal, to the processor 34.
[0023] When a finger is placed over the opening 46, the presence of
the finger deflects the infra-red light towards the sensor 30 so
that the sensor 30 senses the increase of infra-red light (above
the threshold value). Each time a key is pressed, the
piezo-transducer 32 provides a tactile response to the user to
recognize that a key has been pressed.
[0024] Turning to FIG. 4a, a first method of operation of the
keyboard is shown. In this embodiment, once the mobile
communication device is turned on, the light source 42 turns on and
transmits light, preferably infra-red through the light pipe 44
(step 50). It will be understood by one skilled in the art that the
infra-red light is modulated from 20 to 40 khz from the source 42
in order to distinguish the infra-red light from ambient light.
Simultaneously, the processor 34 proceeds to scan the sensors 30
(via the scanning module 38) to determine if any one of the sensors
30 has sensed the presence of an object, such as a finger, near
their associated opening (step 52) represented by a light reading
which is past the threshold value. As discussed above, the bandpass
filter 31 associated with each of the sensors 30, prevents ambient
light (or light which is not at the pre-determined modulated
frequency) from passing through so that the sensor 30 obtains a
reading of the amount of infra-red light to determine if the
associated key has been pressed. Constant checks are performed to
determine when a key selection is sensed (step 54). If no key
selection has been sensed (step 56), the scanning module 38
continues to scan until it senses that one of the set of sensors 30
has created a signal indicating that it has sensed a change in the
amount of infra-red light being sensed thereby bypassing the
threshold value (step 58). This signal, which preferably includes
an identification as to which key has been selected, is then
transmitted to the processor 34. Upon receipt of this signal, the
processor 34 proceeds to enter the interrupt table 36 to interrupt
all applications (step 60) executing on the processor 34 so that
the selected key may be entered into the memory 40 (step 62). After
the selected key has been entered into memory 40, the interrupt is
ended (step 64) and the applications continue executing while the
processor 34 returns to scanning the sensors (step 52) for further
key selections. This process is continued until the mobile
communication device 10 is turned off.
[0025] In another embodiment of a method, as shown in FIG. 4b,
after the mobile communication device 10 is turned on, thereby
activating the light source 42 (step 70), the processor 34 scans
the set of sensors 30 (via the scanning module 38) for an interrupt
signal (step 72). In this method, if a sensor 30 senses a change in
the amount of light being sensed (i.e. passes the threshold value),
the sensor 30 produces an interrupt signal. The scanning module 38
continues to scan the sensors until the interrupt signal is sensed
(step 74). If no interrupt signal is sensed (step 76), the scanning
module continues to scan (step 72). However, once an interrupt
signal is sensed (step 78), the processor 34 enters the interrupt
table 36 to interrupt all the applications currently executing on
the processor 34 (step 80). The scanning module 38 then scans each
of the sensors 30 to determine which of the sensors produced the
interrupt signal (step 82). Once this has been determined, the key
associated with the sensor requesting the interrupt is entered into
the memory 40 (step 84) and the interrupt table exited (step 86) so
that the applications may return to their previous state and
continue executing. The processor 34 then returns to scanning the
sensors for the next interrupt signal (step 72).
[0026] As discussed above, the keyboard preferably includes one
piezo-transducer for the set of sensors to provide a tactile
response to the user's finger so that the user is provided with a
keyboard-like feel when they press one of the keys on the cover.
However, it will be understood that two transducers may be provided
with one at opposite sides of the mobile communication device.
Furthermore, a plurality of transducers, such as one under each of
the sensors, is contemplated, however this decision is generally
based on the overall size of the device. It is understood that less
transducers are preferred as this assists in decreasing the overall
weight and size of the device.
[0027] In another embodiment, the bandpass filter may be a
programmable filter and may also be implemented in software.
[0028] In an alternative embodiment, the light source may be a
light source which provides visible light such as a back-light,
which is used in current mobile communication devices. In order to
sense the visible light, the light is modulated to co-operate with
the characteristics of the bandpass filters associated with the
sensors. This provides an added advantage of saving battery power
since there is no need for a separate light source to operate the
keyboard.
[0029] Alternatively, each row of keys may be set up in its own
light pipe rather than having a single light pipe encompassing all
of the keys.
[0030] The above-described embodiments are intended to be examples
only. Alterations, modifications and variations may be effected to
the particular embodiments by those of skill in the art without
departing from the scope of the invention, which is defined solely
by the claims appended hereto.
* * * * *