U.S. patent application number 13/672321 was filed with the patent office on 2013-09-26 for stylus, pressure detecting system and driving method thereof.
This patent application is currently assigned to SAMSUNG DISPLAY CO., LTD.. The applicant listed for this patent is SAMSUNG DISPLAY CO., LTD.. Invention is credited to Soon-Sung Ahn, Hyoung-Wook Jang.
Application Number | 20130249823 13/672321 |
Document ID | / |
Family ID | 48996596 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130249823 |
Kind Code |
A1 |
Ahn; Soon-Sung ; et
al. |
September 26, 2013 |
STYLUS, PRESSURE DETECTING SYSTEM AND DRIVING METHOD THEREOF
Abstract
A stylus includes a pressure detector for detecting applied
pressure, a first signal generator for generating a signal of a
first frequency, a second signal generator for generating a signal
of a second frequency, and a controller for adjusting at least one
of the first and second signal generators to control an amplitude
ratio of the signal of the first frequency to the signal of the
second frequency according to the applied pressure detected by the
pressure detector.
Inventors: |
Ahn; Soon-Sung; (Yongin-si,
KR) ; Jang; Hyoung-Wook; (Yongin-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG DISPLAY CO., LTD. |
Yongin-si |
|
KR |
|
|
Assignee: |
SAMSUNG DISPLAY CO., LTD.
Yongin-si
KR
|
Family ID: |
48996596 |
Appl. No.: |
13/672321 |
Filed: |
November 8, 2012 |
Current U.S.
Class: |
345/173 ;
345/179 |
Current CPC
Class: |
G06F 2203/04105
20130101; G06F 3/03545 20130101; G06F 3/0383 20130101; G06F
2203/0384 20130101; G06F 3/038 20130101; G06F 3/04162 20190501 |
Class at
Publication: |
345/173 ;
345/179 |
International
Class: |
G06F 3/033 20060101
G06F003/033; G06F 3/041 20060101 G06F003/041 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2012 |
KR |
10-2012-0030587 |
Claims
1. A stylus comprising: a pressure detector for detecting applied
pressure; a first signal generator for generating a signal of a
first frequency; a second signal generator for generating a signal
of a second frequency; and a controller for adjusting at least one
of the first and second signal generators to control an amplitude
ratio of the signal of the first frequency to the signal of the
second frequency according to the applied pressure detected by the
pressure detector.
2. The stylus according to claim 1, wherein the first frequency and
the second frequency are different from each other.
3. The stylus according to claim 1, wherein the first and second
signal generators are respectively configured to emit the signals
of the first and second frequencies through a single signal
emitter.
4. The stylus according to claim 1, wherein the first signal
generator and the second signal generator respectively emit the
signal of the first frequency and the signal of the second
frequency through different signal emitters.
5. The stylus according to claim 1, wherein the controller is
configured to change an amplitude of only one of the signals of the
first and second frequencies to control the amplitude ratio of the
signals of the first and second frequencies.
6. The stylus according to claim 1, wherein the controller is
configured to change both an amplitude of the signal of the first
frequency and an amplitude of the signal of the second frequency to
control the amplitude ratio of the signals of the first and second
frequencies.
7. A pressure detecting system comprising: a stylus comprising: a
pressure detector for detecting applied pressure; a first signal
generator for generating a signal of a first frequency; a second
signal generator for generating a signal of a second frequency; and
a controller for adjusting at least one of the first and second
signal generators to control an amplitude ratio of the signal of
the first frequency to the signal of the second frequency according
to the applied pressure detected by the pressure detector; and a
pressure detecting apparatus for receiving the signals of the first
and second frequencies from the stylus, and for detecting the
applied pressure according to the amplitude ratio of the signal of
the first frequency to the signal of the second frequency.
8. The pressure detecting system according to claim 7, wherein the
first frequency and the second frequency are different from each
other.
9. The pressure detecting system according to claim 7, wherein the
first signal generator and the second signal generator respectively
emit the signal of the first frequency and the signal of the second
frequency through a single signal emitter.
10. The pressure detecting system according to claim 7, wherein the
first signal generator and the second signal generator respectively
emit the signal of the first frequency and the signal of the second
frequency through different signal emitters.
11. The pressure detecting system according to claim 7, wherein the
controller is configured to change an amplitude of only one of the
signals of the first and second frequencies to control the
amplitude ratio of the signals.
12. The pressure detecting system according to claim 7, wherein the
controller is configured to change both the amplitude of the signal
of the first frequency and the amplitude of the signal of the
second frequency to control the amplitude ratio of the signals.
13. A driving method of a pressure detecting system, the method
comprising: detecting applied pressure; controlling an amplitude
ratio of a signal of a first frequency to a signal of a second
frequency according to the detected applied pressure; emitting the
signal of the first frequency and the signal of the second
frequency; receiving the signal of the first frequency and the
signal of the second frequency; calculating the amplitude ratio of
the signal of the first frequency to the signal of the second
frequency; and calculating the pressure from the calculated
amplitude ratio.
14. The method of claim 13, wherein the first frequency and the
second frequency are different from each other.
15. The method of claim 13, wherein controlling the amplitude ratio
comprises changing an amplitude of only one of the signals of the
first and second frequencies to control the amplitude ratio of the
signals.
16. The method of claim 13, wherein controlling the amplitude ratio
comprises changing both an amplitude of the signal of the first
frequency and an amplitude of the signal of the second frequency to
control the amplitude ratio of the signals.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 10-2012-0030587, filed on Mar. 26,
2012, in the Korean Intellectual Property Office, the entire
content of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present invention relate to a stylus, and
to a pressure detecting system including a stylus and a driving
method thereof.
[0004] 2. Description of Related Art
[0005] Recently, a digitizer, a touch screen, or the like, which is
capable of replacing a conventional input device such as a keyboard
and a mouse, and which is capable of directly detecting a position
contacted by a human's hand or an object, has been widely used. In
addition, the use of a stylus system capable of performing more
elaborate, or more accurate, input (as compared to a system using
the human hand) tends to increase.
[0006] To perform various operations corresponding to writing
pressure of the stylus acting on the digitizer (for example, a
control of a thickness of a line drawn by the stylus), desire for
detection of the writing pressure of the stylus has increased. To
this end, according to the related art, a technology wherein a
change in frequency of a signal emitted from the stylus
corresponding to a change in pressure of the stylus, and detection
of the changed frequency to sense the writing pressure of the
stylus, has been used.
[0007] However, because the frequency of the signal emitted from
the stylus is continuously changed, a frequency detection operation
(for example, Fast Fourier transform, or the like) is repeatedly
performed, thereby increasing a processing time and complicating a
hardware configuration.
SUMMARY
[0008] An aspect of embodiments of the present invention provides a
stylus, a pressure detecting system capable of detecting writing
pressure of the stylus without changing a frequency of the signal
emitted from the stylus, and a driving method thereof.
[0009] According to an exemplary embodiment of the present
invention, there is provided a stylus including a pressure detector
for detecting applied pressure, a first signal generator for
generating a signal of a first frequency, a second signal generator
for generating a signal of a second frequency, and a controller for
adjusting at least one of the first and second signal generators to
control an amplitude ratio of the signal of the first frequency to
the signal of the second frequency according to the applied
pressure detected by the pressure detector.
[0010] The first frequency and the second frequency may be
different from each other.
[0011] The first and second signal generators may be respectively
configured to emit the signals of the first and second frequencies
through a single signal emitter.
[0012] The first signal generator and the second signal generator
may respectively emit the signal of the first frequency and the
signal of the second frequency through different signal
emitters.
[0013] The controller might be configured to change an amplitude of
only one of the signals of the first and second frequencies to
control the amplitude ratio of the signals of the first and second
frequencies.
[0014] The controller may be configured to change both an amplitude
of the signal of the first frequency and an amplitude of the signal
of the second frequency to control the amplitude ratio of the
signals of the first and second frequencies.
[0015] According to another exemplary embodiment of the present
invention, there is provided a pressure detecting system including
a stylus including a pressure detector for detecting applied
pressure, a first signal generator for generating a signal of a
first frequency, a second signal generator for generating a signal
of a second frequency, and a controller for adjusting at least one
of the first and second signal generators to control an amplitude
ratio of the signal of the first frequency to the signal of the
second frequency according to the applied pressure detected by the
pressure detector, and a pressure detecting apparatus for receiving
the signals of the first and second frequencies from the stylus,
and for detecting the applied pressure according to the amplitude
ratio of the signal of the first frequency to the signal of the
second frequency.
[0016] The first frequency and the second frequency may be
different from each other.
[0017] The first signal generator and the second signal generator
may respectively emit the signal of the first frequency and the
signal of the second frequency through a single signal emitter.
[0018] The first signal generator and the second signal generator
may respectively emit the signal of the first frequency and the
signal of the second frequency through different signal
emitters.
[0019] The controller might be configured to change an amplitude of
only one of the signals of the first and second frequencies to
control the amplitude ratio of the signals.
[0020] The controller may be configured to change both the
amplitude of the signal of the first frequency and the amplitude of
the signal of the second frequency to control the amplitude ratio
of the signals.
[0021] According to still another exemplary embodiment of the
present invention, there is provided a driving method of a pressure
detecting system, the method including detecting applied pressure,
controlling an amplitude ratio of a signal of a first frequency to
a signal of a second frequency according to the detected applied
pressure, emitting the signal of the first frequency and the signal
of the second frequency, receiving the signal of the first
frequency and the signal of the second frequency, calculating the
amplitude ratio of the signal of the first frequency to the signal
of the second frequency, and calculating the pressure from the
calculated amplitude ratio.
[0022] The first frequency and the second frequency may be
different from each other.
[0023] Controlling the amplitude ratio might include changing an
amplitude of only one of the signals of the first and second
frequencies to control the amplitude ratio of the signals.
[0024] Controlling the amplitude ratio may include changing both an
amplitude of the signal of the first frequency and an amplitude of
the signal of the second frequency to control the amplitude ratio
of the signals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, together with the specification,
illustrate exemplary embodiments of the present invention, and,
together with the description, serve to explain aspects of
embodiments of the present invention.
[0026] FIG. 1 is a diagram showing a pressure detecting system
according to an exemplary embodiment of the present invention.
[0027] FIG. 2 is a block diagram showing a configuration of a
pressure detecting system according to an exemplary embodiment of
the present invention.
[0028] FIGS. 3A to 4C are graphs showing an operation of
controlling an amplitude ratio of two signals corresponding to
pressure applied to a tip of a stylus according to an embodiment of
the present invention.
[0029] FIG. 5 is a block diagram showing a stylus according to
another exemplary embodiment of the present invention.
[0030] FIG. 6 is a flow chart showing a driving method of a
pressure detecting system according to an exemplary embodiment of
the present invention.
DETAILED DESCRIPTION
[0031] Hereinafter, certain exemplary embodiments of the present
invention will be described with reference to the accompanying
drawings. When a first element is described as being coupled to a
second element, the first element may be directly coupled to the
second element, or may be indirectly coupled to the second element
via one or more other elements. Further, some elements that are not
essential to the complete understanding of the embodiments of the
present invention are omitted for clarity. Also, like reference
numerals refer to like elements throughout.
[0032] Specific matters of other exemplary embodiments will be
included in the detailed description and the accompanying drawings.
Aspects of embodiments of the present invention, and methods to
achieve such aspects, will be elucidated from exemplary embodiments
described below in detail with reference to the accompanying
drawings. However, the present invention is not limited to the
exemplary embodiments disclosed below, but may be implemented in
various different forms. Further, in the accompanying drawings,
portions unrelated to the described embodiments of the present
invention may be omitted to improve a description of the
embodiments of the present invention, and same reference numerals
will be used to describe same or similar portions throughout the
present specification.
[0033] Hereinafter, a stylus, a pressure detecting system, and a
driving method thereof will be described with reference to
exemplary embodiments of the present invention, and to drawings for
describing the exemplary embodiments.
[0034] FIG. 1 is a diagram showing a pressure detecting system
according to an exemplary embodiment of the present invention.
Referring to FIG. 1, the pressure detecting system 1 according to
the present embodiment of the present invention includes a stylus
100 and a pressure detecting apparatus 200.
[0035] The stylus 100 is a device capable of being used to input
information by contact with the pressure detecting apparatus, the
stylus 100 being used in lieu of a user's hand. In addition, the
stylus 100 may change an amplitude ratio of two signals emitted
from the stylus 100 to enable writing pressure of the stylus 100 to
be detected by the pressure detecting apparatus 200.
[0036] The pressure detecting apparatus 200 may be, for example, a
digitizer or a touch screen capable of recognizing information
corresponding to an input (e.g., a predetermined input operation)
by the stylus 100, and detecting a position(s) contacted by the
stylus 100 according to a resistive scheme, a capacitive scheme, or
the like. In addition, the pressure detecting apparatus 200 may
detect the writing pressure of the stylus 100 (e.g., pressure
between the stylus and the surface of the pressure detecting
apparatus) from the amplitude ratio of the two signals emitted from
the stylus 100.
[0037] Aspects of the present embodiment are characterized by the
sensing of the writing pressure of the stylus 100. Therefore,
details of the stylus 100 and the pressure detecting apparatus 200
of the present embodiment will be described below.
[0038] FIG. 2 is a block diagram showing a pressure detecting
system according to an exemplary embodiment of the present
invention. Referring to FIG. 2, a stylus 100 according to the
present embodiment may include a pressure detector 120, a first
signal generator 130, a second signal generator 140, and a
controller 150.
[0039] The pressure detector 120 may detect pressure applied to the
stylus 100. For example, the pressure detector 120 may detect
pressure applied to a tip 110 of the stylus 100 according to a
user's writing operation, or according to a user's manipulation of
the stylus. The tip 110 may be coupled to the pressure detector 120
to transfer pressure generated in, or exerted on, the tip 110 to
the pressure detector 120. The tip 110, which is a part capable of
contacting the pressure detecting apparatus 100, may protrude from
one end of the stylus 100.
[0040] Although FIG. 2 shows the pressure detector 120 is
configured to detect the pressure applied to the tip 110 as
described above, the pressure detector 120 may detect other kinds
of externally applied pressure to, or on, the stylus 100, in
addition to the pressure applied through the tip 110. For example,
the pressure detector 120 may detect a strength of a user's grip on
the stylus 100. Therefore, the user controls the strength of the
user's hand gripping the stylus 100, thereby making it possible to
control functions (e.g., a line thickness, a color change, etc.) of
the stylus (e.g., by squeezing the stylus 100 harder). In this
case, for example, the pressure detector 120 may include a variable
capacitor having a capacitance changed by the pressure applied to
the stylus 100. In addition, the pressure detector 120 may include
a variable coil, or a variable resistance (e.g., a variable
resistive element), or may include a resonance circuit having at
least one of the variable capacitor, the variable coil, or the
variable resistance.
[0041] The first signal generator 130 may generate a signal S1 of a
first frequency, and may change an amplitude of the signal S1 of
the first frequency according to control of the controller 150.
[0042] The second signal generator 140 may generate a signal S2 of
a second frequency, and may change an amplitude of the signal S2 of
the second frequency according to the control of the controller
150.
[0043] Each of the first and second signal generators 130 and 140
may generate a signal having a fixed frequency, and may emit the
signal S1 of the first frequency and the signal S2 of the second
frequency to the outside (e.g., may externally emit the signals S1
and S2) via a signal emitter (e.g., a single signal emitter) 160.
Therefore, a separate component for changing the frequency may be
omitted from within the first and second signal generators 130 and
140. In addition, the first and second frequencies may be different
frequencies.
[0044] The controller 150 controls the first signal generator 130
and/or the second signal generator 140 corresponding to the
pressure detected through the pressure detector 120, thereby making
it possible to control an amplitude ratio between the signal S1 of
the first frequency and the signal S2 of the second frequency. In
the present embodiment, the controller 150 may change the
amplitudes of the signal S1 of the first frequency and/or the
signal S2 of the second frequency to have an amplitude ratio
corresponding to the pressure detected through the pressure
detector 120 with reference to a separate lookup table, an
equation, or the like.
[0045] The pressure detecting apparatus 200 may receive the signal
S1 of the first frequency and the signal S2 of the second frequency
emitted from the stylus 100, and may calculate the pressure applied
to the stylus 100 from the amplitude ratio of the signals S1 and
S2. Accordingly, the pressure detecting apparatus 200 may include a
receiver 210 and a pressure calculator 220.
[0046] The receiver 210 may receive the signal S1 of the first
frequency and the signal S2 of the second frequency, which are
emitted from the signal emitter 160 of the stylus 100.
[0047] The pressure calculator 220 calculates the amplitude ratio
of the signal S1 of the first frequency to the signal S2 of the
second frequency received by the receiver 210, and inversely
transforms the calculated amplitude ratio, thereby making it
possible to calculate the pressure applied to the stylus 100. In
the present embodiment, the pressure calculator 220 may refer to
the separate lookup table or the equation (or may refer to a
different lookup table or equation) similar to the controller 150
of the stylus 100.
[0048] In addition, the pressure calculator 220 may include filters
suitable or optimized for signals of the first frequency and the
second frequency to divide the signal received by the receiver 210
into the signal S1 of the first frequency and the signal S2 of the
second frequency. Therefore, the writing pressure of the stylus 100
may be detected by changing only the amplitude of the signals S1
and S2 having the fixed frequencies, and without performing a
complicated process of changing the frequency of the signal.
[0049] FIGS. 3A to 4C are graphs showing an operation of
controlling an amplitude ratio of two signals according to pressure
applied to a tip of a stylus according to an embodiment of the
present invention. FIGS. 3A to 3C show an operation of controlling
an amplitude ratio of the signals S1 and S2 by changing both of the
amplitudes of the signals S1 and S2 of the first and second
frequencies, and FIGS. 4A and 4C show an operation of controlling
an amplitude ratio of the signals S1 and S2 by changing the
amplitude of the signal S1 of the first frequency, while fixing, or
not changing, the amplitude of the signal S2 of the second
frequency.
[0050] Referring to FIG. 3A, when the pressure applied to the tip
110 of the stylus 100 is detected as `A," and when an amplitude
ratio corresponding to the pressure `A` is set to be `a1:a2,` the
controller 150 may control the signal S1 of the first frequency and
the signal S2 of the second frequency to respectively be `na1` and
`na2.` Therefore, the pressure detecting apparatus 200 receiving
the signal S1 of the first frequency having an amplitude of `na1`
and the signal S2 of the second frequency having an amplitude of
`na2` may calculate an amplitude ratio (`a1:a2`) of the signals S1
and S2, and may inversely calculate the `Pressure A` applied to the
tip 110 from the calculated amplitude ratio.
[0051] In addition, referring to FIG. 3B, in the case in which the
pressure applied to the tip 110 of the stylus 100 is changed from
`A` to `B,` and when the amplitude ratio corresponding to the
`Pressure B` is set to be `b1:b2,` the controller 150 may change
the amplitudes of the signal S1 of the first frequency and the
signal S2 of the second frequency to respectively be `nb1` and
`nb2.` Therefore, the pressure detecting apparatus 200 receiving
the signal S1 of the first frequency having the amplitude of `nb1`
and the signal S2 of the second frequency having the amplitude of
`nb2` may calculate an amplitude ratio (`b1:b2`) of the signals S1
and S2, and may inversely calculate the `Pressure B` applied to the
tip 110 from the calculated amplitude ratio.
[0052] Further, referring to FIG. 3C, when the stylus 100 is spaced
apart from, or not in contact with, the pressure detecting
apparatus 200, that is, when the stylus 100 is in a `Hovering`
state, the controller 150 may set the amplitude of the signal S1 of
the first frequency to be `0.` That is, the generation of the
signal S1 of the first frequency may be stopped such that only the
signal S2 of the second frequency is transferred to the pressure
detecting apparatus 200. Therefore, a situation where the pressure
detecting apparatus 200 is receiving only the signal S2 of the
second frequency may indicate that the stylus 100 is in the
hovering state.
[0053] Referring to FIG. 4A, when the pressure applied to the tip
110 of the stylus 100 is detected as `C,` and when an amplitude
ratio corresponding to the `Pressure C` is set to be `1:1,` the
controller 150 may control amplitudes of the signal S1 of the first
frequency and the signal S2 of the second frequency to be the same
as each other. Because the amplitude of the signal S2 of the second
frequency is fixed at, for example, `nc1,` the controller 150 might
control only the amplitude of the signal S1 of the first frequency
to be `nc1.` Therefore, the pressure detecting apparatus 200
receiving the signals S1 and S2 of the first and second frequencies
having the same amplitude of `nc1` may calculate an amplitude ratio
(`1:1`) of the signals S1 and S2, and may inversely calculate the
`Pressure C` applied to the tip 110 from the calculated amplitude
ratio.
[0054] Referring to FIG. 4B, when the pressure applied to the tip
110 of the stylus 100 is changed from `C to D,` and when an
amplitude ratio corresponding to the `Pressure D` is set to be
`d1:c1,` the amplitude of the signal S2 of the second frequency is
fixed at, or set to, `nc1.` Therefore, the controller 150 might
control only the amplitude of the signal S1 of the first frequency
to be `nd1.` Therefore, the pressure detecting apparatus 200
receiving the signal S1 of the first frequency having the amplitude
of `nd1` and the signal S2 of the second frequency having the
amplitude of `nc1` may calculate an amplitude ratio (`d1:c1`) of
the signals S1 and S2, and may inversely calculate the pressure `D`
applied to the tip 110 from the calculated amplitude ratio.
[0055] Referring to FIG. 4C, when the pressure applied to the tip
110 of the stylus 100 is changed from `C` to `0` (that is, when the
stylus 100 is changed to the `Hovering` state), and when an
amplitude ratio corresponding to the pressure `0` is set to be
`e1:c1,` the amplitude of the signal S2 of the second frequency may
be fixed at `nc1.` Therefore, the controller 150 might control, or
change, only the amplitude of the signal S1 of the first frequency
to be `ne1.` Therefore, the pressure detecting apparatus 200
receiving the signal S1 of the first frequency having the amplitude
of `ne1` and the signal S2 of the second frequency having the
amplitude of `nc1` may calculate an amplitude ratio (`e1:c1`) of
the signals S1 and S2, and may inversely calculate the pressure `0`
applied to the tip 110 from the calculated amplitude ratio. Because
only the amplitude of any one of the signal S1 of the first
frequency and the signal S2 of the second frequency is changed, a
hardware configuration may be simplified as compared to changing
the amplitudes of both of the signals S1 and S2.
[0056] FIG. 5 is a diagram showing a stylus according to another
exemplary embodiment of the present invention. Referring to FIG. 5,
the stylus 200 according to another exemplary embodiment may be
configured to include a first signal emitter 161 and a second
signal emitter 162. Therefore, the first and second signal
generators 130 and 140 may respectively externally emit a signal S1
of a first frequency and a signal S2 of a second frequency through
different signal emitters 161 and 162. For example, the first
signal generator 130 may externally emit the signal S1 of the first
frequency through the first signal emitter 161, and the second
signal generator 140 may externally emit the signal S2 of the
second frequency through the second signal emitter 162.
[0057] Only differences between a configuration of the present
embodiment from that of the above-mentioned exemplary embodiment
have been described, and description of similarities of the two
embodiments is omitted.
[0058] FIG. 6 is a flow chart showing a driving method of a
pressure detecting system according to an exemplary embodiment of
the present invention. Referring to FIG. 6, the driving method of
the pressure detecting system according to the present exemplary
embodiment of the present invention includes a pressure detecting
step (S100); an amplitude ratio changing step (S200); a signal
emitting step (S300), an amplitude ratio calculating step (S400),
and a pressure calculating step (S500).
[0059] In the pressure detecting step (S100), pressure applied to
the stylus 100 is detected. In the present embodiment, pressure
applied to the tip 110 of the stylus 100 may be detected, and/or
pressure applied by grip strength of a hand gripping the stylus 100
may be detected. Further, the pressure applied to the stylus 100
may be calculated through the pressure detector 120 including a
variable capacitor, or the like.
[0060] In the amplitude ratio changing step (S200), an amplitude
ratio of a signal S1 of a first frequency to a signal S2 of a
second frequency is changed in a manner corresponding to the
pressure detected in the pressure detecting step (S100). In the
present embodiment, the amplitude ratio of the signals S1 and S2
may be controlled by changing any one of the signals S1 and S2 or
by changing both of the signals S1 and S2. In addition, the first
and second frequencies of the signals S1 and S2 may be different
from each other.
[0061] In the signal emitting step (S300), the signal S1 of the
first frequency and the signal S2 of the second frequency may be
externally emitted. Here, the signal S1 of the first frequency and
the signal S2 of the second frequency may be externally emitted via
a single signal emitter 160 (as shown in FIG. 2), or may be emitted
through different signal emitters 161 and 162 (as shown in FIG.
5).
[0062] In the amplitude ratio calculating step (S400), the
amplitude ratio of the signal S1 of the first frequency to the
signal S2 of the second frequency, which are received in the
pressure detecting apparatus 200, may be calculated.
[0063] In the pressure calculating step (S500), the pressure
applied to the stylus 100 may be calculated using the amplitude
ratio calculated in the amplitude calculating step (S400).
[0064] As set forth above, according to exemplary embodiments of
the present invention, the stylus, the pressure detecting system
for detecting writing pressure of the stylus without changing the
frequency of the signal emitted from the stylus, and the driving
method thereof, may be provided.
[0065] While embodiments of the present invention has been
described in connection with certain exemplary embodiments, it is
to be understood that the invention is not limited to the disclosed
embodiments, but, on the contrary, is intended to cover various
modifications and equivalent arrangements included within the
spirit and scope of the appended claims, and equivalents
thereof.
* * * * *