Information
-
Patent Grant
-
6297778
-
Patent Number
6,297,778
-
Date Filed
Tuesday, November 30, 199925 years ago
-
Date Issued
Tuesday, October 2, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 343 894
- 343 702
- 343 906
- 343 760
- 455 575
- 455 90
-
International Classifications
-
Abstract
An apparatus and method for ensuring proper antenna position of a cordless communication device having a retractable antenna, including a detector such as a light sensor or induction coil for detecting the antenna position, and an indicator for providing audio and/or visual indication of the antenna position.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is directed toward a communication device, and more particularly toward a cordless communication device having an antenna.
2. Background Art
A cordless communication device having a retractable antenna, for example a cellular telephone, receives and transmits signals using the retractable antenna. The communication device operates whether the retractable antenna is in an extended position or a retracted position but, when the antenna is in the extended position, maximum performance is achieved. For example, in a cellular telephone, an antenna rod and an antenna coil mounted on the cellular telephone at a base of the antenna rod radiate the signal from the communication device, providing the ability for maximum performance. However, while the antenna is in the retracted position, minimum performance may be realized. For example, for the cellular telephone, only the antenna coil radiates the signal from the cellular telephone, potentially minimizing performance. Such degraded performance is often disappointing to a user of the cordless communication device.
The present invention is directed to overcoming the problem discussed above.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a cordless communication device including a retractable antenna includes a detector mounted to the cordless communication device for detecting the antenna position and a controller coupled to the detector for determining the antenna position responsive to the detector. An indicator is coupled to the controller for indicating the antenna position.
In one form of this aspect, the detector includes a light emitting diode (LED) for emitting light and a photosensor positioned to sense the LED emitted light when the antenna is in the extended position, and to not sense the LED emitted light when the antenna is in the retracted position. In a further form, the LED is mounted adjacent the photosensor on an inner surface of the electronic device. In a further form, the inner surface is a first inner surface, and a reflector is mounted on a second inner surface for reflecting the emitted light to the photosensor, wherein the reflector, LED and photosensor are relatively positioned such that the emitted light reaches the photosensor when the antenna is in the extended position, and the emitted light does not reach the photosensor when the antenna is in the retracted position.
In another form, the detector includes a coil positioned to change an inductance of the coil when the antenna is placed in the extended position.
In yet another form, the cordless communication device is a cellular telephone.
In another form, the detector detects the antenna position only at a beginning of a call.
In another form of the present invention, the indicator is a speaker, and the controller is adapted to block operation of the speaker when the antenna is in the retracted position.
In another form, the indicator is a speaker, and the controller is adapted to provide an audible signal using the speaker when the antenna is in the retracted position.
In yet another form, the indicator is a display for displaying the antenna position.
In another aspect ofthe present invention, a method for indicating an antenna position of a cordless communication device having a retractable antenna is provided, including detecting the antenna position, and responsive to the detecting, providing an indication of the antenna position when the antenna is in a retracted position.
In a form of this aspect ofthe present invention, the detecting includes emitting light from an LED, and sensing for the emitted light at a photosensor, where the emitted light reaches the photosensor when the antenna is in the extended position, and the emitted light does not reach the photosensor when the antenna is in the retracted position. In a further form, the sensing for emitted light includes reflecting the emitted light from a reflector toward the photosensor.
In another form ofthe present invention, the detecting includes detecting inductance of a coil proximately spaced from the antenna. In a further form, a current is provided through the coil.
In another form, the cordless communication device is a cellular telephone, and the detecting is done only when a call is initiated.
In yet another form, providing an indication includes displaying the antenna position on a visual display for the communication device.
In another form ofthis aspect, providing an indication includes disabling a speaker for the communication device when the antenna position is detected as the retracted position.
In yet another form of this aspect, providing an indication includes providing an audible signal using a speaker for the communication device when the antenna position is detected as the retracted position.
It is an object of the present invention to improve performance of the cordless communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an illustration of a cordless communication device having a retractable antenna in accordance with an embodiment of the present invention;
FIG. 2
a
is a simplified partial cross section of a first embodiment taken along line
2
—
2
of
FIG. 1
, where the antenna is retracted;
FIG. 2
b
is a simplified partial cross section similar to
FIG. 2
a
but with the antenna extended;
FIG. 3
a
is a simplified partial cross section similar to
FIG. 2
a
but of an alternate embodiment;
FIG. 3
b
is a simplified partial cross section of the
FIG. 3
a
embodiment with the antenna extended;
FIG. 4
a
is a schematic diagram of the
FIGS. 3
a
-
3
b
embodiment with the antenna retracted;
FIG. 4
b
is a schematic diagram of the
FIGS. 3
a
-
3
b
embodiment with the antenna extended; and
FIG. 5
is a flowchart illustrating the method of operation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1
is an illustration of a cordless communication device, here a cellular telephone
100
, having a retractable antenna
110
in accordance with an embodiment of the present invention. The cellular telephone
100
includes an antenna base
120
against which the retractable antenna
110
rests when in the retracted position. The antenna base
120
typically includes an antenna coil
125
, which serves to transmit and receive information for the cellular telephone
100
when the antenna
110
is retracted.
The cellular telephone
100
further includes a speaker
130
which provides audible information to a user, and a display device
140
, which provides visual information to the user. The speaker
130
and/or the display
140
are suited to serve as an indicator for indicating the antenna
110
position, as discussed below.
FIGS. 2
a
and
2
b
show a simplified partial cross-section ofthe cellular telephone
100
along line
2
—
2
of FIG.
1
.
FIG. 2
a
shows a cross section where the retractable antenna
110
is retracted in accordance with an embodiment of the present invention.
FIG. 2
b
shows a cross section where the antenna
110
is extended in accordance with an embodiment of the present invention.
A printed circuit board (PCB)
200
is mounted within the cellular telephone
100
. A controller
210
is mounted on the PCB
200
, and is coupled to the speaker
130
, the display
140
and a detector, here shown as a light-emitting diode (LED)
220
and a photosensor
230
. Although no physical connection is shown between the controller
210
and the LED
220
and photosensor
230
, the connection exists via the PCB
200
. A reflector
240
is mounted on an interior wall
280
of the cellular telephone
100
opposite the LED
220
and the photosensor
230
. The LED
220
and the photosensor
230
are positioned on the PCB
200
relative to the antenna
110
such that the antenna
110
, in its retracted position, blocks light emitted by the LED from being detected by the photosensor
230
.
The PCB
200
further includes a PCB coupler
250
which couples the PCB
200
to the antenna coil
125
while the antenna
110
is retracted. The PCB coupler
250
couples the PCB
200
to both the antenna coil
125
and the antenna
110
via an antenna coupler
260
when the antenna is in the extended position shown in
FIG. 2
b.
In operation, light emitted by the LED
220
is blocked by the antenna
110
when the antenna is in the retracted position, as shown in
FIG. 2
a
. The controller
210
is suitably programmed to determine that the antenna is in the retracted position when the controller
210
does not receive a signal from the photosensor
230
indicating that the emitted light from the LED
220
is detected at the photosensor
230
. The controller
210
is further suitably programmed to provide an indication via at least one ofthe speaker
130
and the display
140
. Where the speaker
130
provides the indication, the indication may be an audible signal such as a “beep” or other tone, or may be a pre-recorded message stored in a suitable memory (not shown) in the cellular telephone
100
and sent to the speaker
130
via the controller
210
. The message may be, for example “antenna not extended”. Where the indication is provided by the display
140
, such as a liquid crystal display (LCD), the indication may be a written message, for example “antenna not extended” written on the display
140
, or could be a flashing symbol likely to attract the attention of the user.
When the antenna
110
is extended, shown in
FIG. 2
b
, light emitted by the LED
220
, designated by the arrow
270
is reflected from the reflector
240
, and reflected light designated by an arrow
280
is received at the photosensor
230
. The controller
210
, being coupled to the photosensor
230
receives a signal from the photosensor
230
that the light emitted by the LED
230
is detected, thereby indicating that the antenna
110
is in the extended position.
In a further embodiment, the controller
210
is suitably programmed to cause the LED
220
to emit light only when a call is initiated, for example when the user of the cellular telephone
100
is placing a call, or receiving a call. The controller
210
may direct the LED
220
to stop emitting light when the antenna
110
is extended, or when the call is completed.
In a further embodiment, the controller
210
may provide the indication via the speaker
130
by disabling operation of the speaker
130
until the antenna
110
is placed into the extended position. Once the antenna
110
is placed into the extended position, the controller
210
enables the speaker
130
.
In a further embodiment, one skilled in the art would realize that, depending on the sensitivity of the photosensor
230
, and the type of LED
220
used, a reflector
240
may not be necessary, as the emitted light from the LED
220
may be received at the photosensor
230
when the antenna
110
is extended without use of the reflector
240
. For example, the inner wall
280
of the cellular telephone
100
may be sufficiently reflective for reflecting light emitted by the LED
220
to the photosensor
230
.
In a further embodiment (not shown), where the antenna
110
is guided via a sleeve within the cellular telephone
100
, the sleeve may have holes bored there-through, sufficient for the photosensor
230
to detect light emitted by the LED
220
when the antenna
110
is in the extended position.
In a further embodiment not shown, where the antenna is guided by the sleeve, the sleeve may be formed from a transparent or semi-transparent material sufficient for the light emitted by the LED
220
to be detected at the photosensor
230
when the antenna
110
is in the extended position.
Having the LED
220
and the photosensor
230
for detecting the position ofthe antenna
110
provides improved performance to the user of the cellular telephone
100
, as an indication is provided to the user when the antenna
110
is not in the extended position. Further, having the controller
210
cause the LED
220
to emit light only at the beginning of a call conserves battery power. Additionally, having the speaker
130
and the display
140
provide the user with the indication of the antenna position, thereby directing the user to extend the antenna
110
to achieve maximum potential performance.
In an alternate embodiment of the invention shown in
FIGS. 3
a
and
3
b
, a coil, or inductor
300
is mounted on the PCB
200
and coupled to the controller
210
via the PCB
200
. An inductance change across the coil
300
caused by the antenna
110
allows the controller
210
to determine the antenna position
110
as being retracted (
FIG. 4
a
) or extended (
FIG. 4
b
) as discussed below. Where the controller
210
determines that the antenna
110
is in the retracted position, indications as discussed above may be provided to the user ofthe cellular telephone via the speaker
130
and the display device
140
.
FIGS. 4
a
and
4
b
show electrical schematic diagrams of the cellular telephone
100
for implementing the detector using the coil
300
. An oscillating current source
400
provides an oscillating current “I” through a resistor
410
. The oscillating current source
400
may be provided by the controller
210
, or by a suitable oscillating current source within the cellular telephone
100
. A voltage node
420
coupled to an output of the resistor
410
provides a voltage reading across the coil
300
. The voltage node
420
may be coupled to the controller
210
.
In operation, when the antenna
110
is in the retracted position (
FIG. 4
a
), a voltage, E, at the voltage node
420
impressed across the coil
300
is:
E=2πfLI
where f is the frequency of the oscillating current source
400
in hertz, L is the value of the inductor and the mutual inductance caused by the antenna
110
, and I is the current supplied by the oscillating current source
400
. When the antenna
110
is in the extended position,
FIG. 4
b
, the inductance of the coil
300
changes to L′, thereby causing a voltage E′ to be present at the voltage node
420
to be:
E=2πfL′I
where f is the frequency of the oscillating current source in hertz, L′ is the value of the inductor without the mutual inductance caused by the antenna
110
, and I is the current supplied by the alternating current source
400
.
The controller
210
senses the voltage provided at the voltage node
420
, and thereby determines the position of the antenna
110
as being extended or retracted. The controller
210
may accomplish this using a memory table indexed by voltage values. A first voltage value of approximately E in the memory table indicates the retracted antenna position, and a second voltage value of approximately E′ in the memory table indicates the extended antenna position. The voltage measurement can be done using an analog to digital converter (not shown) and comparing the digital voltage value to the memory table to determine the antenna position. Alternatively, the voltage measurement may be done in the analog domain using rectification and feeding the output to a comparator (not shown) and comparing the analog voltage measurement to a reference, where the output from the comparator indicates to the controller the antenna position.
The value of the current provided by the oscillating current source
400
is determined experimentally as would be known by one skilled in the art, based on a size of the coil
300
, antenna
110
construction, and distance of the coil
300
from the antenna
110
. Typically, the current provided by the oscillating current source
400
will be a very small value in the order of magnitude of microamps, and therefore may be active at all times without significant drain on the battery.
Thus, having the coil
300
as the detector provides a detector which may be active at all times without significantly draining the battery. Further, where an antenna sleeve guides the antenna
110
, the coil
300
provides a detector which may detect the antenna position of the antenna
110
without a specialized antenna sleeve, for example a transparent antenna sleeve or one with holes bored therethrough.
It should be understood that in its broadest scope, the detector could be in forms other than the embodiments shown in
FIGS. 2
a
-
4
b
, and that any structure capable of detecting the antenna position and causing the controller to generate an indication such as described herein when the antenna is retracted could be used within the broad scope of this invention.
FIG. 5
is a flowchart illustrating operation of an embodiment of the present invention. In step
500
, it is detected whether the “yes” key is pushed on the cellular telephone
100
, thereby indicating an initiated call. Where the “yes” key is pushed, the antenna position is detected as shown in step
510
. This may be accomplished as discussed above using the LED
220
and photosensor
230
, or using the coil
300
or other suitable detectors. In step
520
, it is determined whether the antenna
110
is extended. This is accomplished, for example, by the controller
210
determining whether light was detected at the photosensor
230
where the LED
220
and photosensor
230
are the detector, or by determining from a voltage change at the voltage node
420
where the coil
300
is the detector. If it is determined that the antenna is extended, the call continues as normal, shown in step
530
. However, if it is determined that the antenna is not extended, the method proceeds to step
540
where an indication is provided. The indication may be provided via the speaker
130
and/or the display
140
as discussed above. It is then determined in step
550
whether the “no” key is pushed, indicating that the call is ended. Where the “no” key is pushed, the method returns to step
500
and proceeds as previously discussed. If however, the “no” key is not pushed, the method returns to step
510
and proceeds as previously discussed.
Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all ofthe objects and advantages of the present invention and preferred embodiments as described above would be obtained.
Claims
- 1. In a cordless communication device including a retractable antenna, the improvement comprising:a detector mounted to the cordless communication device for detecting the antenna position wherein the detector includes: a light emitting diode (LED) for emitting light; and a photosensor, positioned to sense the LED emitted light when the antenna is in a extended position, and to not sense the LED emitted light when the antenna is in a retracted position; a controller coupled to the detector for determining the antenna position responsive to the detector; and an indicator coupled to the controller for indicating the antenna position.
- 2. The improvement of claim 1 wherein the LED is mounted adjacent the photosensor on an inner surface of the electronic device.
- 3. The improvement of claim 2 wherein the inner surface is a first inner surface, and further including a reflector mounted on a second inner surface for reflecting the emitted light to the photosensor, the reflector, LED and photosensor relatively positioned such that emitted light reaches the photosensor when the antenna is in the extended position, and emitted light does not reach the photosensor when the antenna is in the retracted position.
- 4. In a cordless communication device including a retractable antenna, the improvement comprising:a detector mounted to the cordless communication device for detecting the antenna position; a controller coupled to the detector for determining the antenna position responsive to the detector; and an indicator coupled to the controller for indicating the antenna position, wherein the indicator is a speaker, and the controller is adapted to block operation of the speaker when the antenna is in the retracted position.
- 5. In a cordless communication device including a retractable antenna, the improvement comprising:a detector mounted to the cordless communication device for detecting the antenna position; a controller coupled to the detector for determining the antenna position responsive to the detector; and an indicator coupled to the controller for indicating the antenna position, wherein the indicator is a speaker, and the controller is adapted to provide an audible signal using the speaker when the antenna is in the retracted position.
- 6. A method for indicating an antenna position of a cordless communication device having a retractable antenna, comprising:detecting the antenna position including emitting light from a light emitting diode (LED); and sensing for the emitted light at a photosensor, where the emitted light reaches the photosensor when the antenna is in a extended position, and the emitted light does not reach the photosensor when the antenna is in a retracted position; and responsive to the detecting, providing an indication of the antenna position when the antenna is in a retracted position.
- 7. The method of claim 6 wherein the step of sensing for emitted light includes reflecting the emitted light from a reflector toward the photosensor.
- 8. A method for indicating an antenna position of a cordless communication device having a retractable antenna, comprising:detecting the antenna position: and responsive to the detecting, providing an indication of the antenna position when the antenna is in a retracted position including provid-ing an audible signal using a speaker for the communication device when the antenna position is detected as the retracted position.
US Referenced Citations (7)