U.S. patent application number 17/201613 was filed with the patent office on 2021-07-01 for method carried out by stylus, method carried out by dual stylus and dual controller, and dual stylus.
The applicant listed for this patent is Wacom Co., Ltd.. Invention is credited to Hideyuki Hara, Sadao Yamamoto.
Application Number | 20210200377 17/201613 |
Document ID | / |
Family ID | 1000005459354 |
Filed Date | 2021-07-01 |
United States Patent
Application |
20210200377 |
Kind Code |
A1 |
Hara; Hideyuki ; et
al. |
July 1, 2021 |
METHOD CARRIED OUT BY STYLUS, METHOD CARRIED OUT BY DUAL STYLUS AND
DUAL CONTROLLER, AND DUAL STYLUS
Abstract
An active stylus includes an elongated body, an electrode
provided at a tip end of the elongated body, an indicator, and a
controller coupled to the electrode and the indicator. The
controller is configured to operate, in a mutually exclusive
manner, either in a first mode of operation to transmit a signal of
a first system via the electrode and to receive an uplink signal
transmitted from a sensor which detects, based on the signal of the
first system, a position of the active stylus, or in a second mode
of operation to transmit a signal of a second system via the
electrode. The controller is configured to control the indicator
responsive to a detection of the uplink signal.
Inventors: |
Hara; Hideyuki; (Tokyo,
JP) ; Yamamoto; Sadao; (Tokyo, JP) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Wacom Co., Ltd. |
Saitama |
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JP |
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Family ID: |
1000005459354 |
Appl. No.: |
17/201613 |
Filed: |
March 15, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16227783 |
Dec 20, 2018 |
10949035 |
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17201613 |
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PCT/JP2016/069705 |
Jul 1, 2016 |
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16227783 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/04162 20190501;
G06F 3/03 20130101; G06F 3/0383 20130101; G06F 3/0442 20190501;
G06F 3/0441 20190501; G06F 3/03545 20130101; G06F 3/0446
20190501 |
International
Class: |
G06F 3/044 20060101
G06F003/044; G06F 3/03 20060101 G06F003/03; G06F 3/041 20060101
G06F003/041; G06F 3/0354 20060101 G06F003/0354; G06F 3/038 20060101
G06F003/038 |
Claims
1. An active stylus comprising: an elongated body, an electrode
provided at a tip end of the elongated body, an indicator, and a
controller, which is coupled to the electrode and the indicator and
which is configured to operate, in a mutually exclusive manner,
either in a first mode of operation to transmit a signal of a first
system via the electrode and to receive an uplink signal
transmitted from a sensor which detects, based on the signal of the
first system, a position of the active stylus, or in a second mode
of operation to transmit a signal of a second system via the
electrode, wherein the controller is configured to control the
indicator responsive to a detection of the uplink signal.
2. The active stylus of claim 1, wherein the sensor transmits the
uplink signal based on the signal of the first system transmitted
from the active stylus, and the controller, responsive to the
detection of the uplink signal, controls the indicator to issue an
indication corresponding to the first mode of operation.
3. The active stylus of claim 2, wherein the controller controls
the indicator responsive to a mode switch between the first mode of
operation and the second mode of operation.
4. The active stylus of claim 3, wherein the controller is
configured to operate additionally in an unsettled mode of
operation, which is different from the first mode of operation and
from the second mode of operation, and the controller in the
unsettled mode of operation controls the indicator to issue an
indication, which is different from indications issued in the first
mode of operation or in the second mode of operation.
5. The active stylus of claim 1, wherein the controller controls
the indicator responsive to a mode switch between the first mode of
operation and the second mode of operation.
6. The active stylus of claim 5, wherein the controller is
configured to operate additionally in an unsettled mode of
operation, which is different from the first mode of operation and
from the second mode of operation, and the controller in the
unsettled mode of operation controls the indicator to issue an
indication, which is different from indications issued in the first
mode of operation or in the second mode of operation.
7. The active stylus of claim 1, wherein the controller is
configured to operate additionally in an unsettled mode of
operation, which is different from the first mode of operation and
from the second mode of operation, and the controller in the
unsettled mode of operation controls the indicator to issue an
indication, which is different from indications issued in the first
mode of operation or in the second mode of operation.
8. An active stylus, for use with a sensor controller, the active
stylus comprising: an elongated body, an electrode provided at a
tip end of the elongated body, and a controller, which is coupled
to the electrode and which is configured to operate in a first mode
of operation to transmit a signal of a first system via the
electrode and to switch, responsive to an uplink signal transmitted
from the sensor controller which detects the signal of the first
system, to operate in a second mode of operation to transmit a
signal of a second system.
9. The active stylus of claim 8, wherein the signal of the first
system includes information indicating that the active stylus is
capable of operating in the second mode of operation.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present disclosure relates to a method carried out by a
stylus, a method carried out by a dual stylus and a dual
controller, and a dual stylus.
2. Description of the Related Art
[0002] In recent years, electronic equipment including a stylus
that transmits a signal by using capacitive coupling has been
attracting attention as an input device. This kind of electronic
equipment further includes a touch sensor and a sensor controller,
and the sensor controller is configured to receive a signal from
the stylus received through the touch sensor and carry out position
detection and writing pressure detection of the stylus based on the
received signal.
[0003] Regarding the above-described electronic equipment,
electronic equipment of various systems have come into existence in
recent years. Concrete examples thereof are disclosed in PCT Patent
Publication No. WO2015/111159, Japanese Patent Laid-Open No.
2014-63249, U.S. Pat. No. 8,536,471, and U.S. Patent Application
Publication No. 2012-0105362 (hereinafter, Patent Documents 1 to 4,
respectively).
[0004] In Patent Document 1, electronic equipment of a so-called
active capacitive system is disclosed, in which detection of the
existence and position of a stylus is enabled by using electrodes
prepared in a touch panel in order to carry out finger detection. A
sensor controller according to this example does not have a signal
transmission function, and transmission of signals is carried out
only in one direction from the stylus to the sensor controller.
[0005] Electronic equipment of the active capacitive system is
disclosed also in Patent Document 2. A sensor controller according
to this example has a signal transmission function, and
transmission of signals is carried out bi-directionally between a
stylus and the sensor controller.
[0006] Another example in which transmission of signals is carried
out only in one direction from a stylus to a sensor controller is
disclosed in Patent Document 3, and another example in which
transmission of signals is carried out bi-directionally between a
stylus and a sensor controller is disclosed in Patent Document
4.
[0007] As above, electronic equipment of various kinds of systems
exist as electronic equipment including a stylus. However,
generally, compatibility does not exist among the respective
systems. As a result, in the past, for example when a user lays
electronic equipment compatible with only a first system and
electronic equipment compatible with only a second system side by
side and attempts to use them alternately, the user would need to
change (switch) the styluses every time the electronic equipment
are switched, which has been inconvenient.
SUMMARY OF THE INVENTION
[0008] In view of the above-described situation, applicant has been
researching on introduction of a stylus and a sensor controller
compatible with plural systems. Hereinafter, the stylus and the
sensor controller compatible with plural systems will be referred
to as a dual stylus and a dual controller, respectively. For
example, in the above-described example, the need to change the
styluses every time the electronic equipment are switched is
eliminated by using the dual stylus compatible with both the first
system and the second system.
[0009] During the research, applicant has discovered that the dual
stylus and the dual controller may encounter the following
problems. A detailed description will be made below.
[0010] First, there is a problem that a long time is often
necessary from contact between the dual stylus and a touch surface
to decision of the operation mode of the dual stylus. If the sensor
controller has a function of transmitting a signal from the touch
surface, the dual stylus can determine the type of the sensor
controller by receiving the signal before coming in contact with
the touch surface.
[0011] However, signal reception by the dual stylus and signal
transmission by the sensor controller both need to be intermittent.
Thus, when operation of the user is quick, or the like, the dual
stylus often comes in contact with the touch surface in the state
in which the stylus has not yet received the signal from the sensor
controller. In such a case, input by the dual stylus cannot be made
for a while after the contact with the touch surface (until the
timing of signal reception by the dual stylus and the timing of
signal transmission by the sensor controller next coincide with
each other), resulting in causing user inconvenience.
[0012] Second, there is a problem that the dual stylus and the dual
controller do not necessarily operate in the optimum operation mode
when they are used in combination. The plural systems with which
the dual stylus and the dual controller are compatible are not
prepared as completely-parallel systems but they are actually
assigned the order of priority. Specifically, suppose that a dual
stylus and a dual controller compatible with a first system and a
second system exist and a higher order of priority is set for the
first system than the second system. In this case, in the case of
carrying out communication between the dual stylus and the dual
controller, which are both compatible with the first system, the
communication should be carried out pursuant to the first system
having a higher priority.
[0013] However, for example if both the dual stylus and the dual
controller each carry out transmission and reception of signals
pursuant to the first system and the second system intermittently,
they may recognize that their operation counterpart is equipment
compatible with the second system, depending on the timing. In such
a case, communication pursuant to the second system is started and
communication pursuant to the first system is not carried out.
[0014] Furthermore, for example if the first system with the higher
order of priority is compatible with bidirectional communication
and the second system with the lower order of priority is
compatible with unidirectional communication from the stylus to the
sensor controller, it is conceivable that the dual stylus is
operated pursuant to the second system upon detection of the
writing pressure in order to rapidly implement rendering when touch
operation is carried out. In this case, communication pursuant to
the first system is not carried out.
[0015] Therefore, the present disclosure provides a method carried
out by a stylus, a method carried out by a dual stylus and a dual
controller, and a dual stylus that can solve the above-described
problems relating to the dual stylus and the dual controller.
[0016] A method carried out by a dual stylus according to the
present disclosure is a method carried out by a dual stylus that is
configured to be capable of transmitting both a signal pursuant to
a first system and a signal pursuant to a second system and is
configured to be capable of receiving at least a signal pursuant to
the first system. The dual stylus has a detection function of
detecting a writing pressure applied to a pen tip. The method
includes detecting contact between the dual stylus and a touch
surface based on the writing pressure detected by the detection
function, starting reception operation of the signal pursuant to
the first system in response to detection of contact between the
dual stylus and the touch surface, and, if a signal pursuant to the
first system is received in the reception operation, setting an
operation mode of the dual stylus to a first operation mode, in
which signals are transmitted and received pursuant to the first
system.
[0017] A method carried out by a dual stylus and a dual controller
according to the present disclosure is a method carried out by a
dual stylus that is configured to be capable of transmitting both a
signal pursuant to a first system and a signal pursuant to a second
system and is configured to be capable of receiving at least a
signal pursuant to the first system, and a dual controller that is
configured to be capable of receiving both a signal pursuant to the
first system and a signal pursuant to the second system and is
configured to be capable of transmitting at least a signal pursuant
to the first system. The method includes transmitting, by the dual
stylus, a first signal pursuant to the second system, wherein the
first signal includes function information indicating that the dual
stylus is compatible with the first system. The method includes
transmitting, by the dual controller, a second signal including an
instruction to switch to a first operation mode, in which signals
are transmitted and received pursuant to the first system, in
response to reception of the first signal from the dual stylus. The
method includes switching, by the dual stylus, an operation mode of
the dual stylus to the first operation mode in response to
reception of the second signal from the dual controller.
[0018] A dual stylus according to one aspect of the present
disclosure is a dual stylus that is configured to be capable of
transmitting both a signal pursuant to a first system and a signal
pursuant to a second system and is configured to be capable of
receiving at least a signal pursuant to the first system. The dual
stylus includes a detector having a detection function of detecting
a writing pressure applied to a pen tip and a controller that
activates a signal reception operation pursuant to the first system
for a predetermined time period in response to detection of contact
between the dual stylus and a touch surface based on the writing
pressure detected by the detection function. The controller, when a
signal is received pursuant to the first system in the
predetermined time period, sets an operation mode of the dual
stylus to a first operation mode, in which signals are transmitted
and received pursuant to the first system.
[0019] A dual stylus according to another aspect of the present
disclosure is a dual stylus that is configured to be capable of
transmitting both a signal pursuant to a first system and a signal
pursuant to a second system and is configured to be capable of
receiving at least a signal pursuant to the first system. The dual
stylus includes a controller that transmits a first signal pursuant
to the second system, wherein the first signal includes function
information indicating that the dual stylus is compatible with the
first system. The controller, after transmitting the first signal,
in response to reception of a second signal from a sensor
controller, wherein the second signal is indicative of an
instruction to switch to a first operation mode, switches an
operation mode of the dual stylus to the first operation mode, in
which signals are transmitted and received pursuant to the first
system.
[0020] A dual stylus according to another aspect of the present
disclosure is a dual stylus that is configured to be capable of
transmitting both a signal pursuant to a first system and a signal
pursuant to a second system and is configured to be capable of
receiving at least a signal pursuant to the first system. The dual
stylus includes an indicator, and a controller that determines
whether operation is to be carried out in a first operation mode,
in which the signal pursuant to the first system is transmitted, or
operation is to be carried out in a second operation mode, in which
the signal pursuant to the second system is transmitted, and
controls the indicator to carry out indication differently between
when the determined operation mode is the first operation mode and
when the determined operation mode is the second operation
mode.
[0021] According to the methods carried out by the stylus in
accordance with the present disclosure, the stylus can start the
reception operation of the signal pursuant to the first system
immediately after contact with the touch surface. Therefore, it
becomes possible to shorten the time from the contact with the
touch surface to setting the stylus to the first operation
mode.
[0022] Furthermore, according to the methods carried out by the
dual stylus and the dual controller in accordance with the present
disclosure, even when the operation mode of the dual stylus is the
second operation mode in which transmission (and reception) of the
signal pursuant to the second system is carried out, the operation
mode of the dual stylus can be switched to the first operation mode
by an instruction from the dual controller that has ascertained
that the dual stylus is compatible with the first system.
Therefore, it becomes possible to start communication pursuant to
the first system between the dual stylus and the dual
controller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagram depicting the configuration of a
position detecting system according to an embodiment of the present
disclosure;
[0024] FIG. 2 is a diagram depicting the configuration of a sensor
controller according to the embodiment of the present
disclosure;
[0025] FIG. 3 is a mode transition diagram of a stylus and the
sensor controller according to a first embodiment of the present
disclosure;
[0026] FIG. 4 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the first embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to a background
art of the present disclosure;
[0027] FIG. 5 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the first embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the
background art of the present disclosure;
[0028] FIG. 6 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the first embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the present
embodiment;
[0029] FIG. 7 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the first embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the present
embodiment;
[0030] FIG. 8 is a processing flowchart depicting operation of the
stylus according to the first embodiment of the present
disclosure;
[0031] FIG. 9 is a processing flowchart depicting the operation of
the stylus according to the first embodiment of the present
disclosure;
[0032] FIG. 10 is a processing flowchart depicting the operation of
the stylus according to the first embodiment of the present
disclosure;
[0033] FIG. 11 is a processing flowchart depicting operation of the
sensor controller according to the first embodiment of the present
disclosure;
[0034] FIG. 12 is a processing flowchart depicting the operation of
the sensor controller according to the first embodiment of the
present disclosure;
[0035] FIG. 13 is a processing flowchart depicting the operation of
the sensor controller according to the first embodiment of the
present disclosure;
[0036] FIG. 14 is a mode transition diagram of the stylus and the
sensor controller according to a second embodiment of the present
disclosure;
[0037] FIG. 15 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the second embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the
background art of the present disclosure;
[0038] FIG. 16 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the second embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the present
embodiment;
[0039] FIG. 17 is a diagram depicting signals transmitted and
received between the stylus and the sensor controller according to
the second embodiment of the present disclosure when the stylus and
the sensor controller carry out operation according to the present
embodiment;
[0040] FIG. 18 is a processing flowchart depicting operation of the
stylus according to the second embodiment of the present
disclosure;
[0041] FIG. 19 is a processing flowchart depicting the operation of
the stylus according to the second embodiment of the present
disclosure;
[0042] FIG. 20 is a processing flowchart depicting the operation of
the stylus according to the second embodiment of the present
disclosure;
[0043] FIG. 21 is a processing flowchart depicting operation of the
sensor controller according to the second embodiment of the present
disclosure;
[0044] FIG. 22 is a processing flowchart depicting the operation of
the sensor controller according to the second embodiment of the
present disclosure;
[0045] FIG. 23 is a processing flowchart depicting the operation of
the sensor controller according to the second embodiment of the
present disclosure; and
[0046] FIG. 24 is a processing flowchart depicting the operation of
the sensor controller according to the second embodiment of the
present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Embodiments of the present disclosure will be described in
detail below with reference to the accompanying drawings.
[0048] FIG. 1 is a diagram depicting the configuration of a
position detecting system 1 according to a first embodiment of the
present disclosure. As depicted in this diagram, the position
detecting system 1 includes a stylus 2 and electronic equipment 3.
The electronic equipment 3 is a tablet-type computer for example,
and has a sensor 30 forming a touch surface 3t, a sensor controller
31, and a system controller 32 that controls the respective
elements of the sensor controller 31.
[0049] The stylus 2 and the sensor controller 31 are a dual stylus
and a dual controller, respectively, compatible with system A
(first system) and system B (second system) that do not have
compatibility with each other. Systems A and B are both compatible
with bidirectional communication between the stylus 2 and the
sensor controller 31. Systems A and B are given the order of
priority and a higher order of priority is set for system A than
system B.
[0050] Dashed arrows C1 to C5 in FIG. 1 represent a typical cycle
of operation of the stylus 2 by a user. Furthermore, a sensing
range SR depicted in FIG. 1 represents a range in which either one
of the stylus 2 and the sensor controller 31 can detect the other
through reception, by the stylus 2, of an uplink signal US
transmitted by the sensor controller 31 or reception, by the sensor
controller 31, of a downlink signal DS transmitted by the stylus
2.
[0051] When drawing a line on the touch surface 3t by using the
stylus 2, a user repeats a series of cycle in which the stylus 2 is
moved (down) from outside of the sensing range SR to inside of the
sensing range SR (C1, C2) and is moved to draw a desired trace on
the touch surface 3t (C3) and thereafter is moved (up) from inside
of the sensing range SR to outside of the sensing range SR (C4,
C5). In the present specification, the entry of the stylus 2 into
the sensing range SR in down-operation will be referred to as first
pen-down PD1 and a contact with the touch surface 3t by the stylus
2 will be referred to as second pen-down PD2.
[0052] As depicted in FIG. 1, the stylus 2 has a core body 20, an
electrode 21, a writing pressure detector 22, a switch 23, a signal
processor (processing circuit) 24, a power supply 25, and an
indicator 26.
[0053] The core body 20 is an elongated member disposed in such a
manner that the longitudinal direction thereof corresponds with the
pen axis direction of the stylus 2, and forms the pen tip of the
stylus 2. An electrically-conductive material is applied on the
surface of the tip part of the core body 20 and forms the electrode
21. The rear (proximal) end part of the core body 20 is made to
abut against the writing pressure detector 22. The writing pressure
detector 22 detects the writing pressure level according to the
pressure applied to the tip of the core body 20 (writing pressure
applied to the core body 20) when the pen tip of the stylus 2 is
pressed against the touch surface 3t of the sensor controller 31 or
the like. In a concrete example, the writing pressure detector 22
is formed of a variable-capacitance module whose capacitance
changes according to the writing pressure.
[0054] The electrode 21 is an electrical conductor disposed near
the core body 20 and is electrically connected to the signal
processor 24 by wiring. When the stylus 2 transmits the downlink
signal DS toward the sensor controller 31, the downlink signal DS
is supplied from the signal processor 24 to the electrode 21 and,
in response to this, a charge according to the contents of the
downlink signal DS is induced in the electrode 21. This causes
change in the capacitance in the sensor 30 to be described later
and the sensor controller 31 receives the downlink signal DS by
detecting this change. Furthermore, when the uplink signal US
transmitted by the sensor controller 31 reaches the electrode 21, a
charge according to the uplink signal US that has reached is
induced in the electrode 21. The signal processor 24 receives the
uplink signal US by detecting the charge thus induced in the
electrode 21.
[0055] The switch 23 is a side switch disposed on the side surface
of the casing of the stylus 2 for example, and functions as an
input unit configured to be capable of accepting operation by the
user. Specifically, the switch 23 is configured to, according to
the state of operation by the user (pressed-down state), output
switch information indicating its own pressed-down state to the
signal processor 24. The switch information is information that
indicates either one of two states of on-state and off-state, for
example.
[0056] The signal processor 24 has a function of receiving the
uplink signal US transmitted by the sensor controller 31 pursuant
to system A or system B through the electrode 21, a function of
generating the downlink signal DS pursuant to system A or system B
and transmitting the downlink signal DS toward the sensor
controller 31 through the electrode 21, and a function of detecting
the second pen-down PD2 (contact with the touch surface 3t) based
on the writing pressure level detected by the writing pressure
detector 22. Which of systems A and B is used by the signal
processor 24 is decided according to the operation mode of the
stylus 2. This point will be described later.
[0057] As described later, the uplink signal US often includes
various kinds of command, and the signal processor 24 in this case
acquires the command by demodulating and decoding the received
uplink signal US and generates the downlink signal DS in accordance
with the acquired command. Specifically, based on an instruction by
the command, the signal processor 24 generates the downlink signal
DS including various kinds of information, such as the writing
pressure level detected by the writing pressure detector 22 and the
switch information output from the switch 23.
[0058] Furthermore, the signal processor 24 holds a unique
identification (ID) of the stylus 2 in a memory, which is not
depicted in the diagram. The unique ID is information used in
common in the plural systems with which the stylus 2 is compatible
(in this case, systems A and B), and includes information
indicating the plural systems with which the stylus 2 is
compatible. The signal processor 24 is configured to cause function
information including all or part of this unique ID (including at
least information sufficient for the sensor controller 31 to
determine that the stylus 2 is compatible with system A) to be
included in the downlink signal DS and transmit the downlink signal
DS when being instructed by a command included in the uplink signal
US or voluntarily at a timing according to any trigger including
reception of the uplink signal US or the second pen-down PD2.
[0059] The power supply 25 is a unit configured to supply operating
power (direct current voltage) to the signal processor 24 and is
formed of an AAAA battery with a circular cylindrical shape, for
example.
[0060] The indicator 26 is configured to inform (notify) a user of
various kinds of information relating to the stylus 2, and is
formed of a light emitting diode for example. The indicator 26 will
be described in detail in a third embodiment to be described
later.
[0061] FIG. 2 is a diagram depicting the configuration of the
sensor controller 31. The configuration of the sensor 30 is also
depicted in this diagram. As depicted in this diagram, the sensor
30 has a configuration in which plural linear electrodes 30X and
plural linear electrodes 30Y are disposed in a matrix manner and is
capacitively coupled to the stylus 2 based on these linear
electrodes 30X and 30Y. The sensor 30 is used for detection of not
only the stylus 2 but also a finger. Furthermore, the sensor
controller 31 includes a transmitter 60, a selecting circuit 40, a
receiver 50, a logic unit 70, and a micro-controller unit (MCU)
80.
[0062] The transmitter 60 is a circuit configured to generate and
transmit the uplink signal US pursuant to system A or system B and
includes a pattern supply circuit 61, a switch 62, a spreading
processor 63, a code string holding circuit 64, and a transmission
guard circuit 65 for example. The concrete configuration of the
transmitter 60 described here is exemplification and is different
in some cases depending on the system. Furthermore, if systems A
and B need the transmitters 60 with configurations different from
each other, the respective configurations may be disposed together
in one transmitter 60 and be selectively operated. Which of systems
A and B is used by the transmitter 60 is decided according to the
operation mode of the sensor controller 31. This point will be
described later.
[0063] The pattern supply circuit 61 holds a detection pattern c1
and has a function of repeatedly outputting a signal (or bit
string) corresponding to the detection pattern c1 consecutively
during a predetermined consecutive transmission period (for example
3 milliseconds) in accordance with an instruction of a control
signal ctrl_t1 supplied from the logic unit 70. Furthermore, the
pattern supply circuit 61 also has a function of outputting a
predetermined delimiter pattern STP at least twice consecutively
immediately after the end of this consecutive transmission period
or at the time of transmission start of control information c2 to
be described later. The pattern supply circuit 61 may be disposed
in the MCU 80 although being disposed in the transmitter 60 in FIG.
2.
[0064] The detection pattern c1 is a pattern of the values of
symbols used for detection of the existence of the sensor
controller 31 by the stylus 2 and is made known to the stylus 2 in
advance (before the stylus 2 detects the sensor controller 31). The
symbol is the unit of information used for modulation in
transmission processing (unit of information expressed by a
transmission signal) and is the unit of information obtained by
demodulating one symbol that is a received signal in reception
processing. The values of the symbol can include a value converted
to a bit string (hereinafter, referred to as "bit string
corresponding value") and a value that is not converted to a bit
string by the stylus 2 that has received the symbol (hereinafter,
referred to as "bit string non-corresponding value"). As depicted
in Table 1 to be described later, the symbols relating to the
former take a power-of-two number of values and can be associated
with bit strings of "0001" and so forth. The bit length of each
symbol represented by a bit string in this manner is decided
depending on the specifications of the spreading processor 63. On
the other hand, the symbols relating to the latter take one or more
(for example two) values and take values that are represented as
"P," "M," or the like, and are not associated with a bit string as
depicted in Table 1 to be described later. In one example depicted
in Table 1 to be described later, "P" and "M" are associated with a
predetermined spreading code string and an inverted code string
thereof, respectively.
[0065] The detection pattern c1 is represented by a pattern of the
bit string non-corresponding value. Specifically, the detection
pattern c1 is formed of repetition of two bit string
non-corresponding values "P" and "M" as in "PMPMPM . . . ."
[0066] The delimiter pattern STP is a pattern of the symbols for
notifying the stylus 2 of the end of the above-described
consecutive transmission period and is formed of a pattern of the
symbols that does not appear in repetition of the detection pattern
c1. To take one example, if the detection pattern c1 is formed of
repetition of two bit string non-corresponding values "P" and "M"
as in "PMPMPM . . . " as described above, the delimiter pattern STP
can be formed of a pattern "PP" obtained by making the bit string
non-corresponding value "P" consecutive twice. The configurations
of the delimiter pattern STP and the detection pattern c1 may be
reversed, so that the delimiter pattern may be formed of "PM" and
the detection pattern c1 may be formed of "PP."
[0067] The switch 62 has a function of selecting either one of the
pattern supply circuit 61 and the MCU 80 based on a control signal
ctrl_t2 supplied from the logic unit 70 and supplying output of the
selected one to the spreading processor 63. If the switch 62
selects the pattern supply circuit 61, the detection pattern c1 or
the delimiter pattern STP is supplied to the spreading processor
63. On the other hand, if the switch 62 selects the MCU 80, the
control information c2 is supplied from the MCU 80 to the spreading
processor 63.
[0068] The control information c2 is information including a
command indicating the contents of an instruction to the stylus 2
and is generated by the MCU 80. The control information c2 includes
the value of the symbol (for example 0 to 15) associated with a bit
string with a variable length, and is different from the detection
pattern c1 in that the value is not shared with the stylus 2 in
advance. Furthermore, the control information c2 is different from
the detection pattern c1 including the values "P" and "M" in that
the control information c2 is represented by a value "D" that
represents a power-of-two number of values with the above-described
predetermined bit length (e.g., eight (=2.sup.3) values).
[0069] The code string holding circuit 64 has a function of
generating and holding a spreading code PN with an 11-chip length
having auto-correlation property based on a control signal ctrl_t3
supplied from the logic unit 70. The spreading code PN held by the
code string holding circuit 64 is supplied to the spreading
processor 63.
[0070] The spreading processor 63 has a function of obtaining a
transmission chip string with a 12-chip length by modulating the
spreading code PN held by the code string holding circuit 64 based
on the value of the symbol supplied through the switch 62
(information expressed by a transmission signal by processing of
the spreading processor 63). This function will be described below
by taking a concrete example.
[0071] Suppose that, in the example described below, each of the
detection pattern c1, the delimiter pattern STP, and the control
information c2 is formed of a combination of the bit string
corresponding values 0 to 15 (corresponding bit strings "0000" to
"1111") and the bit string non-corresponding values "P" and "M."
Furthermore, suppose that the spreading code PN held by the code
string holding circuit 64 is "00010010111." In this case, the
spreading processor 63 converts the values of the respective
symbols (0 to 15 and P and M) to transmission chip strings in
accordance with Table 1 depicted below.
TABLE-US-00001 TABLE 1 Corresponding Transmission Value of bit
Shift chip symbol string Polarity amount string P Non- Non- 0
100010010111 corresponding inversion (Basis) 0 0000 Non- +2
111000100101 inversion 1 0001 Non- +3 111100010010 inversion 3 0011
Non- +4 101110001001 inversion 2 0010 Non- +5 110111000100
inversion 6 0110 Non- +6 101011100010 inversion 7 0111 Non- +7
100101110001 inversion 5 0101 Non- +8 110010111000 inversion 4 0100
Non- +9 (-2) 101001011100 inversion M Non- Inversion 0 011101101000
corresponding (Basis) 8 1000 Inversion +2 000111011010 9 1001
Inversion +3 000011101101 11 1011 Inversion +4 010001110110 10 1010
Inversion +5 001000111011 14 1110 Inversion +6 010100011101 15 1111
Inversion +7 011010001110 13 1101 Inversion +8 001101000111 12 1100
Inversion +9 (-2) 010110100011
[0072] As depicted in Table 1, in this example, first the value "P"
of the symbol is converted to a transmission chip string obtained
by giving "1" to the beginning of the spreading code PN
"00010010111." Furthermore, each of the values "0" to "7" of the
symbols is converted to a transmission chip string obtained by
giving "1" to the beginning of a code string obtained through
cyclic shift of the spreading code PN "00010010111" by the shift
amount depicted in Table 1. The values "M" and "8" to "15" of the
other symbols are each converted to a transmission chip string
obtained by inverting the transmission chip string corresponding to
a respective one of the values "P" and "0" to "7" of the
symbols.
[0073] The spreading processor 63 is configured to obtain the
transmission chip string by the above conversion processing and
supply the transmission chip string to the transmission guard
circuit 65.
[0074] The transmission guard circuit 65 has a function of
inserting a guard period based on a control signal ctrl_t4 supplied
from the logic unit 70. The guard period is a period during which
both transmission and reception are suspended for switching between
transmission operation and reception operation between a
transmission period of the uplink signal US and a reception period
in which a signal from the stylus 2 is received.
[0075] The selecting circuit 40 is a switch that carries out
switching between a transmission period in which a signal is
transmitted from the sensor 30 and a reception period in which a
signal is received by the sensor 30 based on control by the logic
unit 70. Specifically, the selecting circuit 40 includes switches
44x and 44y and conductor selecting circuits 41x and 41y. The
switch 44x operates to connect the output terminal of the
transmitter 60 to the input terminal of the conductor selecting
circuit 41x in the transmission period and connect the output
terminal of the conductor selecting circuit 41x to the input
terminal of the receiver 50 in the reception period based on a
control signal sTRx supplied from the logic unit 70. The switch 44y
operates to connect the output terminal of the transmitter 60 to
the input terminal of the conductor selecting circuit 41y in the
transmission period and connect the output terminal of the
conductor selecting circuit 41y to the input terminal of the
receiver 50 in the reception period based on a control signal sTRy
supplied from the logic unit 70. The conductor selecting circuit
41x operates to select one or plural electrodes in the plural
linear electrodes 30X and connect the selected electrodes to the
switch 44x based on a control signal selX supplied from the logic
unit 70. The conductor selecting circuit 41y operates to select one
or plural electrodes in the plural linear electrodes 30Y and
connect the selected electrodes to the switch 44y based on a
control signal selY supplied from the logic unit 70. It is, for
example, when the uplink signal US is transmitted from the whole
surface of the touch surface 3t that the plural linear electrodes
30X or the plural linear electrodes 30Y are selected by the
conductor selecting circuit 41x or 41y.
[0076] The receiver 50 is a circuit for receiving the downlink
signal DS pursuant to system A or system B in accordance with a
control signal ctrl_r of the logic unit 70. Specifically, the
receiver 50 includes an amplification circuit 51, a detection
circuit 52, and an analog-digital (AD) converter 53. The concrete
configuration of the receiver 50 described here is also
exemplification and is different in some cases depending on the
system. Furthermore, if systems A and B need the receivers 50 with
configurations different from each other, the respective
configurations may be disposed together in one receiver 50 and be
selectively operated. Which of systems A and B is used by the
receiver 50 is decided according to the operation mode of the
sensor controller 31. This point will be described later.
[0077] The amplification circuit 51 amplifies and outputs the
downlink signal DS supplied from the selecting circuit 40. The
detection circuit 52 is a circuit that generates a voltage
corresponding to the level of the output signal of the
amplification circuit 51. The AD converter 53 is a circuit that
generates a digital signal by sampling the voltage output from the
detection circuit 52 at a predetermined time interval. The digital
signal output by the AD converter 53 is supplied to the MCU 80.
[0078] The logic unit 70 and the MCU 80 are controllers that
control transmission and reception operation of the transmitter 60,
the receiver 50, and so forth. Specifically, the MCU 80 is a
microprocessor that has read-only memory (ROM) and random access
memory (RAM) inside and operates based on a predetermined program.
Meanwhile, the logic unit 70 is configured to output the
above-described respective control signals based on control by the
MCU 80. Furthermore, the MCU 80 is configured to execute processing
of deriving coordinate data x and y and so forth indicating the
position of the stylus 2 based on the digital signal supplied from
the AD converter 53 and outputting the coordinate data x and y and
so forth to the system controller 32. The MCU 80 is configured to
execute processing of, if the digital signal supplied from the AD
converter 53 represents some kind of data, acquiring the data and
outputting the data to the system controller 32.
[0079] FIG. 3 is a mode transition diagram of the stylus 2 and the
sensor controller 31 in the present embodiment. As depicted in this
diagram, the stylus 2 and the sensor controller 31 according to the
present embodiment are configured to operate in any of unsettled
mode P, operation mode A (first operation mode) in which
communication pursuant to system A is carried out, and operation
mode B (second operation mode) in which communication pursuant to
system B is carried out. Among them, unsettled mode P means the
state in which a device as a communication counterpart has not yet
been detected. In unsettled mode P, which of operation modes A and
B operation should be carried out has not been decided and
transmission and reception of signals pursuant to systems A and B
are alternately repeated as described later. Unsettled mode P can
be referred to as a dual mode in which operation is alternately
carried out in plural operation modes of systems A and B and so
forth, and can also be referred to as a discovery mode as a mode in
which any sensor controller 31 or stylus 2 is being detected. The
stylus 2 may execute processing of switching indication of the
indicator 26 in response to the transition of these operation
modes. This point will be described in the third embodiment to be
described later.
[0080] Here, with reference to FIG. 4 and FIG. 5, a description
will be made about a problem caused when the stylus 2 and the
sensor controller 31 compatible with systems A and B carry out
operation according to the background art of the present
disclosure. The operation of the stylus 2 and the sensor controller
31 to be described with reference to FIG. 4 and FIG. 5 is carried
out also in operation according to the present embodiment, except
for a point to be particularly described later.
[0081] FIG. 4 is a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31 when the
stylus 2 and the sensor controller 31 carry out the operation
according to the background art of the present disclosure. In the
example of this diagram, the first pen-down PD1 occurs at a clock
time t0 and the second pen-down PD2 occurs at a clock time t1. The
operation mode of each of the stylus 2 and the sensor controller 31
at the timing before the occurrence of the first pen-down PD1 is
unsettled mode P, as depicted in FIG. 4.
[0082] In unsettled mode P, the stylus 2 alternately repeats
reception operation of the uplink signal US pursuant to system A
and reception operation of the uplink signal US pursuant to system
B, and the sensor controller 31 sequentially repeats transmission
operation of the uplink signal US pursuant to system A, reception
operation of the downlink signal DS pursuant to system A,
transmission operation of the uplink signal US pursuant to system
B, and reception operation of the downlink signal DS pursuant to
system B. Here, the reception operation and the transmission
operation of the respective signals are carried out continuously
for a predetermined time defined for each in advance. This point is
the same also regarding reception operation and transmission
operation of the respective signals to be described later.
Furthermore, regarding each system, the cycle of the transmission
operation of the uplink signal US by the sensor controller 31 and
the cycle of the reception operation of the uplink signal US by the
stylus 2 are configured in such a manner that either one cycle is
not a multiple of the other. The purpose thereof is to avoid the
occurrence of a situation in which the stylus 2 cannot receive the
uplink signal US transmitted by the sensor controller 31
indefinitely, despite that the uplink signal US reaches the stylus
2. Furthermore, it is preferable that the continuation time of the
reception operation by each system (above-described predetermined
time) be set to at least a time equal to or longer than the
transmission cycle of the corresponding uplink signal US (cycle of
transmission by the sensor controller 31), as with the continuation
time of reception operation of the uplink signal US carried out by
the stylus 2 from the clock time t1 in FIG. 6 to be described
later. Moreover, it is preferable for the reception operation of
the stylus 2 to be repeatedly carried out with the intermediary of
a break period, during which reception operation is not carried out
to avoid wasting the power supply 25 (FIG. 1), also as depicted in
FIG. 4.
[0083] The most preferable mode transition of the stylus 2 and the
sensor controller 31 in response to the occurrence of the first
pen-down PD1 and the second pen-down PD2 is that the stylus 2 and
the sensor controller 31 both enter operation mode A between the
clock time t0 and the clock time t1 (that is, before the occurrence
of the second pen-down PD2). This is implemented through execution,
between the clock time t0 and the clock time t1, of a series of
processing in which the stylus 2 receives the uplink signal US
pursuant to system A and the sensor controller 31 receives the
downlink signal DS transmitted by the stylus 2 that has started
operation in operation mode A due to the reception of the uplink
signal US and, thereby, the sensor controller 31 also starts
operation in operation mode A.
[0084] However, in the case in which a user quickly operates the
stylus 2 and the interval between the clock time t0 and the clock
time t1 is short, or the like, the situation may arise in which the
stylus 2 cannot receive the uplink signal US for a while even after
passing through the clock time t1, as exemplified in FIG. 4. In the
example of FIG. 4, the stylus 2 receives the uplink signal US
transmitted pursuant to system A finally at a clock time t2 after
the clock time t1, and the stylus 2 enters operation mode A as a
result. Then, at a subsequent clock time t3, the sensor controller
31 that has received the downlink signal DS transmitted pursuant to
system A enters operation mode A, and communication between the
stylus 2 and the sensor controller 31 pursuant to system A is
started. That is, delay corresponding to the time t3-t1 occurs from
the occurrence of the second pen-down PD2 at the clock time t1 to
the start of the communication between the stylus 2 and the sensor
controller 31 pursuant to system A at the clock time t3. The
occurrence of this delay is one of problems in the background art
of the present embodiment.
[0085] FIG. 5 is also a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31 when the
stylus 2 and the sensor controller 31 carry out the operation
according to the background art of the present disclosure. The
example of this diagram is different from the example depicted in
FIG. 4 in terms of the timing of reception operation of the stylus
2 (relative timing with respect to transmission operation of the
sensor controller 31).
[0086] As a result of the above-described difference, the stylus 2
receives the uplink signal US transmitted pursuant to system B and
enters operation mode B at the clock time t2 in the example of FIG.
5. In response to this, the sensor controller 31 also enters
operation mode B at the clock time t3, so that communication
between the stylus 2 and the sensor controller 31 pursuant to
system B is started. Because the order of priority of system B is
low compared with system A, it is not preferable that the
communication pursuant to system B be started as above between the
stylus 2 and the sensor controller 31 compatible with both systems
A and B, and it is desired to quickly carry out switching to
communication pursuant to system A. This is another of the problems
in the background art of the present embodiment.
[0087] FIG. 6 is a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31 when the
stylus 2 and the sensor controller 31 carry out operation according
to the present embodiment. In this diagram, particularly operation
of the stylus 2 for avoiding the above-described delay is
depicted.
[0088] As depicted in FIG. 6, after detecting the second pen-down
PD2 at the clock time t1, the stylus 2 immediately starts reception
operation of the uplink signal US pursuant to system A if its own
operation mode is still unsettled mode P. This reception operation
is continued for at least a time equal to or longer than the
transmission cycle of the sensor controller 31 (cycle SP1 depicted
in the diagram) until the uplink signal US pursuant to system A is
received. Due to this, if the sensor controller 31 transmits the
uplink signal US pursuant to system A, the stylus 2 can surely
receive the uplink signal US pursuant to system A unless the stylus
2 leaves the sensing range SR (FIG. 1). In addition, because the
reception operation of the uplink signal US pursuant to system A is
started immediately after the occurrence of the second pen-down
PD2, the delay from the second pen-down PD2 to the start of
communication pursuant to system A can also be minimized.
[0089] FIG. 7 is also a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31
according to the present embodiment. Particularly this diagram
depicts operation of the stylus 2 and the sensor controller 31 for
switching to communication pursuant to system A with the higher
order of priority after communication pursuant to system B with the
lower order of priority is started. Even when the stylus 2 and the
sensor controller 31 carry out the operation according to the
present embodiment, such a situation possibly occurs, for example,
if the stylus 2 receives the uplink signal US pursuant to system B
between the clock time t0 and the clock time t1.
[0090] As depicted in FIG. 7, the stylus 2 that has started
operation in operation mode B transmits the downlink signal DS (D1,
first signal) including the unique ID at an arbitrary clock time
t4. As this arbitrary clock time t4, a clock time according to the
uplink signal US from the sensor controller 31 or a command
included therein may be employed, or a clock time according to the
clock time t2, when the stylus 2 has started the operation in
operation mode B, may be employed. When receiving the downlink
signal DS (D1), the sensor controller 31 acquires the unique ID
included therein by demodulation and decoding. Then, the sensor
controller 31 determines whether or not the stylus 2 is compatible
with also system A based on the acquired unique ID. If determining
that the stylus 2 is compatible, the sensor controller 31 transmits
the uplink signal US (D2, second signal) including a command that
represents an instruction for switching to operation mode A at a
clock time t5. When receiving the uplink signal US (D2) at a clock
time t6, the stylus 2 acquires the switching instruction included
therein by demodulation and decoding. Then, in response to the
acquired switching instruction, the sensor controller 31 switches
its own operation mode to operation mode A at a clock time t7.
[0091] The required time from the transmission of the uplink signal
US (D2) by the sensor controller 31 to the transition of the stylus
2 to operation mode A can be decided in advance as part of the
specifications of the stylus 2. Therefore, the sensor controller 31
may know, in advance, the clock time t7, at which the stylus 2 that
has received the switching instruction makes the transition to
operation mode A and, thus, may execute processing of switching its
own operation mode to operation mode A at the clock time t7.
Thereby, communication pursuant to system A with the higher order
of priority is started between the stylus 2 and the sensor
controller 31.
[0092] FIG. 8 to FIG. 10 are processing flowcharts depicting the
operation of the stylus 2 according to the present embodiment. With
reference to these diagrams, the operation of the stylus 2
according to the present embodiment will be described in more
detail below.
[0093] As depicted in FIG. 8, first the stylus 2 sets its own
operation mode to unsettled mode P (step S11). Then, the stylus 2
detects each of the arrival of the start timing of reception
pursuant to system A, the arrival of the start timing of reception
pursuant to system B, and the occurrence of the second pen-down
(steps S12 and S14). If the start timing of reception pursuant to
system A has arrived or if the second pen-down has occurred, the
stylus 2 activates reception operation of the uplink signal US
pursuant to system A (step S13). This reception operation when the
second pen-down has occurred is continued for at least a time equal
to or longer than the transmission cycle of the sensor controller
31 (cycle SP1 depicted in FIG. 6) until the uplink signal US
pursuant to system A is received as described above. Furthermore,
if the start timing of reception pursuant to system B has arrived,
the stylus 2 activates reception operation of the uplink signal US
pursuant to system B (step S15).
[0094] Moreover, the stylus 2 determines whether or not the uplink
signal US has been received by the reception operation started in
the step S13 or the step S15 (step S16). If determining that the
uplink signal US has been received by the reception operation
started in the step S13 (that is, if the uplink signal US pursuant
to system A has been received), the stylus 2 switches its own
operation mode to operation mode A (step S17). If determining that
the uplink signal US has been received by the reception operation
started in the step S15 (that is, if the uplink signal US pursuant
to system B has been received), the stylus 2 switches its own
operation mode to operation mode B (step S18).
[0095] FIG. 9 depicts operation of the stylus 2 after operation in
operation mode A is started. As depicted in this diagram, the
stylus 2 detects each of the arrival of the transmission start
timing and the arrival of the reception start timing (steps S21 and
S23). Then, the stylus 2 activates transmission operation of the
downlink signal DS pursuant to system A (step S22) if the
transmission start timing has arrived, and activates reception
operation of the uplink signal US pursuant to system A (step S24)
if the reception start timing has arrived.
[0096] Furthermore, the stylus 2 determines whether or not the
uplink signal US has been received by the reception operation
started in the step S24 (step S25). If determining that the uplink
signal US has been received, the stylus 2 returns to the step S21
and repeats the processing. On the other hand, if determining that
the uplink signal US has not been received, the stylus 2 returns
its own operation mode to unsettled mode P (step S26) and returns
the processing to the step S12 in FIG. 8. This processing is
executed in order to return the stylus 2 to unsettled mode P when
the stylus 2 is separated from the touch surface 3t.
[0097] FIG. 10 depicts operation of the stylus 2 after operation in
operation mode B is started. As depicted in this diagram, the
stylus 2 detects each of the arrival of the transmission start
timing and the arrival of the reception start timing (steps S31 and
S33). Then, the stylus 2 activates transmission operation of the
downlink signal DS pursuant to system B (step S32) if the
transmission start timing has arrived, and activates reception
operation of the uplink signal US pursuant to system B (step S34)
if the reception start timing has arrived.
[0098] Furthermore, the stylus 2 determines whether or not the
uplink signal US has been received by the reception operation
started in the step S34 (step S35). If determining that the uplink
signal US has been received, the stylus 2 determines whether or not
an instruction for switching to operation mode A is included
therein (step S36). If determining that the switching instruction
is included as a result, the stylus 2 switches its own operation
mode to operation mode A (step S37) and moves the processing to the
step S21 in FIG. 9. On the other hand, if determining that the
switching instruction is not included, the stylus 2 returns to the
step S31 and repeats the processing.
[0099] If determining that the uplink signal US has not been
received in the step S35, the stylus 2 returns its own operation
mode to unsettled mode P (step S38) and returns the processing to
the step S12 in FIG. 8. This processing is executed in order to
return the stylus 2 to unsettled mode P when the stylus 2 is
separated from the touch surface 3t, similarly to the step S26 in
FIG. 9.
[0100] FIG. 11 to FIG. 13 are processing flowcharts depicting
processing executed by the sensor controller 31 according to the
present embodiment. With reference to these diagrams, the operation
of the sensor controller 31 according to the present embodiment
will be described in more detail below.
[0101] As depicted in FIG. 11, first the sensor controller 31 sets
its own operation mode to unsettled mode P (step S41). Then, the
sensor controller 31 detects each of the arrival of the start
timing of reception pursuant to system A, the arrival of the start
timing of transmission pursuant to system A, the arrival of the
start timing of reception pursuant to system B, and the arrival of
the start timing of transmission pursuant to system B (steps S42,
S44, S46, and S48). If the start timing of reception pursuant to
system A has arrived, the sensor controller 31 activates reception
operation of the downlink signal DS pursuant to system A (step
S43). Similarly, if the start timing of transmission pursuant to
system A has arrived, the sensor controller 31 activates
transmission operation of the uplink signal US pursuant to system A
(step S45). If the start timing of reception pursuant to system B
has arrived, the sensor controller 31 activates reception operation
of the downlink signal DS pursuant to system B (step S47). If the
start timing of transmission pursuant to system B has arrived, the
sensor controller 31 activates transmission operation of the uplink
signal US pursuant to system B (step S49).
[0102] Furthermore, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S43 or the step S47 (step S50). Then,
if determining that the downlink signal DS has been received by the
reception operation started in the step S43 (that is, if the
downlink signal DS pursuant to system A has been received), the
sensor controller 31 switches its own operation mode to operation
mode A (step S51). If determining that the downlink signal DS has
been received by the reception operation started in the step S47
(that is, if the downlink signal DS pursuant to system B has been
received), the sensor controller 31 switches its own operation mode
to operation mode B (step S52).
[0103] FIG. 12 depicts operation of the sensor controller 31 after
operation in operation mode A is started. As depicted in this
diagram, the sensor controller 31 detects each of the arrival of
the transmission start timing and the arrival of the reception
start timing (steps S61 and S63). Then, the sensor controller 31
activates transmission operation of the uplink signal US pursuant
to system A (step S62) if the transmission start timing has
arrived, and activates reception operation of the downlink signal
DS pursuant to system A (step S64) if the reception start timing
has arrived.
[0104] Furthermore, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S64 (step S65). If determining that
the downlink signal DS has been received, the sensor controller 31
returns to the step S61 and repeats the processing. On the other
hand, if determining that the downlink signal DS has not been
received, the sensor controller 31 returns its own operation mode
to unsettled mode P (step S66) and returns the processing to the
step S42 in FIG. 11. This processing is executed in order to return
the sensor controller 31 to unsettled mode P when the stylus 2 is
separated from the touch surface 3t.
[0105] FIG. 13 depicts operation of the sensor controller 31 after
operation in operation mode B is started. As depicted in this
diagram, the sensor controller 31 detects each of the arrival of
the transmission start timing and the arrival of the reception
start timing (steps S71 and S73). Then, the sensor controller 31
activates transmission operation of the uplink signal US pursuant
to system B (step S72) if the transmission start timing has
arrived, and activates reception operation of the downlink signal
DS pursuant to system B (step S74) if the reception start timing
has arrived.
[0106] Furthermore, the sensor controller 31 determines whether or
not an instruction for switching to operation mode A has been
included in the uplink signal US and been transmitted (step S75).
If determining that the switching instruction has been transmitted,
the sensor controller 31 switches its own operation mode to
operation mode A at the timing at which the stylus 2 makes a
transition to operation mode A (step S76). Thereafter, the sensor
controller 31 moves to the step S61 in FIG. 12 and continues the
processing.
[0107] If determining that the switching instruction has not been
transmitted in the step S75, next the sensor controller 31
determines whether or not the downlink signal DS has been received
by the reception operation started in the step S74 (step S77). If
determining that the downlink signal DS has not been received here,
the sensor controller 31 returns its own operation mode to
unsettled mode P (step S78) and returns the processing to the step
S42 in FIG. 11. This processing is executed in order to return the
sensor controller 31 to unsettled mode P when the stylus 2 is
separated from the touch surface 3t, similarly to the step S66 in
FIG. 12.
[0108] If determining that the downlink signal DS has been received
in the step S77, the sensor controller 31 determines whether or not
function information indicating that the stylus 2 is compatible
with system A is included in the received downlink signal DS (step
S79). Specifically, the function information is information that
represents all or part of the unique ID of the stylus 2, as
described above. If determining that the function information
indicating that the stylus 2 is compatible with system A is
included in the downlink signal DS, the sensor controller 31 sets a
command including an instruction for switching to operation mode A
as one of pieces of information transmitted by the uplink signal US
(step S80). The command thus set is transmitted when the step S72
is next carried out. Then, in the subsequent step S75, it is
determined that an instruction for switching to operation mode A
has been included in the uplink signal US and been transmitted. As
a result of such processing, both the stylus 2 and the sensor
controller 31 make a transition to operation mode A.
[0109] As described above, according to the method carried out by
the stylus 2 in accordance with the present embodiment, the stylus
2 can activate reception operation of a signal pursuant to system A
immediately after contacting the touch surface 3t. Therefore, it
becomes possible to shorten the time from the contact with the
touch surface 3t to setting the stylus 2 to operation mode A.
[0110] Furthermore, according to the method carried out by the
stylus 2 and the sensor controller 31 in accordance with the
present embodiment, even when the operation mode of the stylus 2 is
operation mode B, in which transmission and reception of a signal
pursuant to system B are carried out, the operation mode of the
stylus 2 can be switched to operation mode A by an instruction by
the sensor controller 31 that has ascertained that the stylus 2 is
compatible with system A. Therefore, it becomes possible to start
communication pursuant to system A between the stylus 2 and the
sensor controller 31.
[0111] Next, a second embodiment of the present disclosure will be
described. The stylus 2 and the sensor controller 31 according to
the present embodiment are different from the stylus 2 and the
sensor controller 31 according to the first embodiment in that they
are compatible, instead of system B, with system C compatible with
unidirectional communication from the stylus 2 to the sensor
controller 31. They are the same in the other points. Therefore,
the description will be made with focus on the different point in
the following. A higher order of priority is set for system A than
system C.
[0112] FIG. 14 is a mode transition diagram of the stylus 2 and the
sensor controller 31 in the present embodiment. As depicted in this
diagram, the stylus 2 and the sensor controller 31 according to the
present embodiment are configured to operate in any of unsettled
mode P, operation mode A (first operation mode) in which
communication pursuant to system A is carried out, and operation
mode C (second operation mode) in which communication pursuant to
system C is carried out.
[0113] Here, with reference to FIG. 15, a description will be made
about a problem caused when the stylus 2 and the sensor controller
31 compatible with systems A and C carry out operation according to
the background art of the present disclosure. The operation of the
stylus 2 and the sensor controller 31 to be described with
reference to FIG. 15 is carried out also in operation according to
the present embodiment, except for a point to be particularly
described later.
[0114] FIG. 15 is a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31 when the
stylus 2 and the sensor controller 31 carry out the operation
according to the background art of the present disclosure. Also in
the example of this diagram, similarly to the example of FIG. 4 and
so forth, the first pen-down PD1 occurs at the clock time t0 and
the second pen-down PD2 occurs at the clock time t1. The operation
mode of each of the stylus 2 and the sensor controller 31 at the
timing before the occurrence of the first pen-down PD1 is unsettled
mode P, as depicted in FIG. 15.
[0115] In unsettled mode P, the stylus 2 is configured to
alternately repeat transmission operation of the downlink signal DS
pursuant to system C and reception operation of the uplink signal
US pursuant to system A. However, in the example of FIG. 15, the
reception operation of the uplink signal US pursuant to system A is
omitted once every two times for reduction in the power
consumption. In the present disclosure, such operation is also
included in the operation of "alternately repeating transmission
operation of the downlink signal DS pursuant to system C and
reception operation of the uplink signal US pursuant to system A."
Furthermore, the sensor controller 31 is configured to sequentially
repeat transmission operation of the uplink signal US pursuant to
system A, reception operation of the downlink signal DS pursuant to
system A, and reception operation of the downlink signal DS
pursuant to system C. Here, the cycle at which the stylus 2
transmits the downlink signal DS pursuant to system C and the cycle
at which the sensor controller 31 receives the downlink signal DS
pursuant to system C are configured in such a manner that either
one cycle is not a multiple of the other. This is the same also
regarding the cycle at which the stylus 2 receives the uplink
signal US pursuant to system A and the cycle at which the sensor
controller 31 transmits the uplink signal US pursuant to system A.
The purpose of this is to avoid the occurrence of a situation in
which, although a signal transmitted by one device reaches the
other device, the other device cannot receive the signal
indefinitely.
[0116] Also in the example of FIG. 15, the most preferable mode
transition of the stylus 2 and the sensor controller 31 in response
to the occurrence of the first pen-down PD1 and the second pen-down
PD2 is that the stylus 2 and the sensor controller 31 both enter
operation mode A between the clock time t0 and the clock time t1
(that is, before the occurrence of the second pen-down PD2). This
is implemented through execution, between the clock time t0 and the
clock time t1, of a series of processing in which the stylus 2
receives the uplink signal US pursuant to system A and the sensor
controller 31 receives the downlink signal DS transmitted by the
stylus 2 that has started operation in operation mode A due to the
reception of the uplink signal US and, thereby, the sensor
controller 31 also starts operation in operation mode A, similarly
to the case of FIG. 4.
[0117] However, in the case in which a user quickly operates the
stylus 2 and the interval between the clock time t0 and the clock
time t1 is short, or in the case in which the stylus 2 cannot
detect the uplink signal US, the situation may arise in which the
stylus 2 is still incapable of receiving the uplink signal US even
when the clock time t1 is reached, as exemplified in FIG. 15. Thus,
according to the operation according to the background art, if the
clock time t1 is reached without a transition to operation mode A,
the stylus 2 immediately switches its own operation mode to
operation mode C. Due to this, the stylus 2 exclusively carries out
transmission operation of the downlink signal DS pursuant to system
C. Thus, the sensor controller 31 also makes a transition to
operation mode C eventually and communication between the stylus 2
and the sensor controller 31 pursuant to system C is started (clock
time t2). It is not preferable that the communication pursuant to
system C be started in this manner between the stylus 2 and the
sensor controller 31 compatible with both systems A and C.
Therefore, it is desired to prevent the start of communication
pursuant to system C, or to quickly carry out switching to
communication pursuant to system A, even when the communication
pursuant to system C is started. They are problems in the
background art of the present embodiment.
[0118] FIG. 16 is a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31 when the
stylus 2 and the sensor controller 31 carry out operation according
to the present embodiment. This diagram particularly depicts
operation of the stylus 2 for preventing the start of communication
pursuant to system C even when the clock time t1 is reached without
a transition to operation mode A.
[0119] As depicted in FIG. 16, even when the operation mode of the
stylus 2 is still unsettled mode P after the stylus 2 detects the
second pen-down PD2 at the clock time t1, the stylus 2 does not
make a transition to operation mode C, but immediately activates
reception operation of the uplink signal US pursuant to system A.
This reception operation is continued for at least a time equal to
or longer than the transmission cycle of the sensor controller 31
(cycle SP2 depicted in the diagram) until the uplink signal US
pursuant to system A is received. Due to this, if the sensor
controller 31 transmits the uplink signal US pursuant to system A,
the stylus 2 can surely receive the uplink signal US pursuant to
system A unless the stylus 2 leaves the sensing range SR (FIG. 1).
Therefore, communication pursuant to system C is not started and
communication pursuant to system A can be started.
[0120] FIG. 17 is also a diagram depicting signals transmitted and
received between the stylus 2 and the sensor controller 31
according to the present embodiment. Particularly this diagram
depicts operation of the stylus 2 and the sensor controller 31 for
switching to communication pursuant to system A with the higher
order of priority after communication pursuant to system C with the
lower order of priority is started. When the stylus 2 and the
sensor controller 31 according to the present embodiment are used,
communication pursuant to system C is not started as described with
reference to FIG. 16. Thus, basically the case in which the
operation described here is necessary should not exist. However, it
is also possible that the stylus 2 will fail to receive the uplink
signal US for some reason and communication pursuant to system C
will be started as a result (for example in the case in which, as
in FIG. 18 to be described later, the stylus 2 fails to receive the
uplink signal US pursuant to system A in a step S108 although the
sensor controller 31 transmits it, and the stylus 2 decides its own
operation mode as operation mode C in a step S111, or the like).
Therefore, the operation described here may be necessary. Although
being based on the premise that the stylus 2 is operating in
operation mode C here, the operation described below is the same
also when the stylus 2 is operating in unsettled mode P.
[0121] As depicted in FIG. 17, the stylus 2 that is operating in
operation mode C continuously transmits the downlink signal DS (D3,
first signal) including function information (specifically, all or
part of the unique ID) indicating that the stylus 2 is compatible
with systems A and C.
[0122] When the sensor controller 31 receives the downlink signal
DS (D3) at the clock time t1 subsequent to the clock time t0 when
the first pen-down PD1 has occurred, the operation mode of the
sensor controller 31 changes to operation mode C. At this time, the
sensor controller 31 determines which system the stylus 2 is
compatible with, based on the unique ID included in the downlink
signal DS (D3). Then, if determining that the stylus 2 is
compatible with system A, from then on, the sensor controller 31
temporarily switches its own operation mode to operation mode A and
carries out transmission of the uplink signal US (second signal)
pursuant to system A every time the transmission of the downlink
signal DS is interrupted. The uplink signal US thus transmitted has
a role as an instruction to switch to operation mode A.
[0123] The stylus 2 attempts reception of the uplink signal US
pursuant to system A at a timing when the sensor controller 31 will
transmit the uplink signal US if the sensor controller 31 carries
out the above-described operation. Specifically, the stylus 2 may
carry out reception operation of the uplink signal US pursuant to
system A in the transmission interval of the downlink signal DS.
However, the consumption of the power supply 25 (FIG. 1) becomes
large if the reception operation is invariably carried out in the
transmission interval. Therefore, it is preferable to carry out the
reception operation of the uplink signal US pursuant to system A,
for example, in the transmission interval (between the clock time
t3 and the clock time t4) of the downlink signal DS immediately
after detection of the second pen-down PD2 (clock time t2), as
depicted in FIG. 17. Of course, the reception operation of the
uplink signal US pursuant to system A may be carried out at the
stage before detection of the second pen-down PD2 (including the
period between the first pen-down PD1 and the second pen-down PD2).
This allows the stylus 2 to detect the uplink signal US pursuant to
system A before the arrival of the clock time t2 (uplink signal US
pursuant to system A located on the later side relative to the
clock time t1 in FIG. 17).
[0124] When receiving the uplink signal US pursuant to system A at
the clock time t4, the stylus 2 switches its own operation mode to
operation mode A. Meanwhile, the sensor controller 31 attempts
reception of the downlink signal DS pursuant to system A after
transmitting the uplink signal US pursuant to system A several
times. In the example of FIG. 17, this attempt is carried out after
the second round of transmission. However, this attempt may be
carried out after the first round of transmission or may be carried
out after the third or subsequent round of transmission.
Furthermore, the reception of the downlink signal DS pursuant to
system A may be attempted plural times. As a result of attempting
reception of the downlink signal DS pursuant to system A in this
manner, the sensor controller 31 that has actually received the
downlink signal DS pursuant to system A at the clock time t5
switches its own operation mode to operation mode A in response to
this, and carries out operation in operation mode A from then on.
Thereby, communication pursuant to system A is started between the
stylus 2 and the sensor controller 31.
[0125] FIG. 18 to FIG. 20 are processing flowcharts depicting the
operation of the stylus 2 according to the present embodiment. With
reference to these diagrams, the operation of the stylus 2
according to the present embodiment will be described in more
detail below.
[0126] As depicted in FIG. 18, first the stylus 2 decides its own
operation mode as unsettled mode P (step S101). Then, the stylus 2
detects each of the arrival of the start timing of reception
pursuant to system A and the arrival of the start timing of
transmission pursuant to system C (steps S102 and S104). If the
start timing of reception pursuant to system A has arrived, the
stylus 2 activates reception operation of the uplink signal US
pursuant to system A (step S103). Furthermore, if the start timing
of transmission pursuant to system C has arrived, the stylus 2
activates transmission operation of the downlink signal DS pursuant
to system C (step S105).
[0127] Moreover, the stylus 2 determines whether or not the uplink
signal US has been received by the reception operation started in
the step S103 (step S106). If determining that the uplink signal US
has been received (that is, if the uplink signal US pursuant to
system A has been received), the stylus 2 switches its own
operation mode to operation mode A (step S110).
[0128] The stylus 2 also determines whether or not the second
pen-down PD2 has occurred concurrently with the determination in
the step S106 (step S107). If determining that the second pen-down
PD2 has occurred, the stylus 2 activates reception operation of the
uplink signal US pursuant to system A separately from the periodic
reception operation in the step S103 (step S108). This reception
operation is continued for at least a time equal to or longer than
the transmission cycle of the sensor controller 31 (cycle SP2
depicted in FIG. 16) until the uplink signal US pursuant to system
A is received as described above. Then, the stylus 2 determines
whether or not the uplink signal US has been received by this
reception operation (step S109). If determining that the uplink
signal US has been received, the stylus 2 switches its own
operation mode to operation mode A (step S110). On the other hand,
if determining that the uplink signal US has not been received, the
stylus 2 switches its own operation mode to operation mode C (step
S111). If determining that the second pen-down PD2 has not occurred
in the step S107, the stylus 2 returns to the step S102 and
continues the processing.
[0129] FIG. 19 depicts operation of the stylus 2 after operation in
operation mode A is started. As depicted in this diagram, the
stylus 2 detects each of the arrival of the transmission start
timing and the arrival of the reception start timing (steps S121
and S123). Then, the stylus 2 activates transmission operation of
the downlink signal DS pursuant to system A (step S122) if the
transmission start timing has arrived, and activates reception
operation of the uplink signal US pursuant to system A (step S124)
if the reception start timing has arrived.
[0130] Furthermore, the stylus 2 determines whether or not the
uplink signal US has been received by the reception operation
started in the step S124 (step S125). If determining that the
uplink signal US has been received, the stylus 2 returns to the
step S121 and repeats the processing. On the other hand, if
determining that the uplink signal US has not been received, the
stylus 2 returns its own operation mode to unsettled mode P (step
S126) and returns the processing to the step S102 in FIG. 18. This
processing is executed in order to return the stylus 2 to unsettled
mode P when the stylus 2 is separated from the touch surface
3t.
[0131] FIG. 20 depicts operation of the stylus 2 after operation in
operation mode C is started. As depicted in this diagram, the
stylus 2 detects the arrival of the transmission start timing
(steps S131), and activates transmission operation of the downlink
signal DS pursuant to system C (step S132) if the transmission
start timing has arrived.
[0132] Furthermore, the stylus 2 also determines whether or not the
second pen-down PD2 has occurred concurrently with the
determination in the step S131 (step S133). If determining that the
second pen-down PD2 has occurred, the stylus 2 activates reception
operation of the uplink signal US pursuant to system A at the
timing when transmission of the uplink signal US by the sensor
controller 31 is expected (step S134). This timing when
transmission is expected is a transmission interval of the downlink
signal DS pursuant to system C, for example. Then, if the uplink
signal US pursuant to system A has been received, the stylus 2
switches its own operation mode to operation mode A (step S136) and
moves the processing to the step S121 in FIG. 19. If the uplink
signal US pursuant to system A has not been received, the stylus 2
returns to the step S131 and continues the processing in operation
mode C. Also when determining that the second pen-down PD2 has not
occurred in the step S133, the stylus 2 returns to the step S131
and continues the processing.
[0133] FIG. 21 to FIG. 24 are processing flowcharts depicting
processing executed by the sensor controller 31 according to the
present embodiment. With reference to these diagrams, the operation
of the sensor controller 31 according to the present embodiment
will be described in more detail below.
[0134] As depicted in FIG. 21, first the sensor controller 31
decides its own operation mode to unsettled mode P (step S141).
Then, the sensor controller 31 detects each of the arrival of the
start timing of reception pursuant to system A, the arrival of the
start timing of transmission pursuant to system A, and the arrival
of the start timing of reception pursuant to system C (steps S142,
S144, and S146). If the start timing of reception pursuant to
system A has arrived, the sensor controller 31 activates reception
operation of the downlink signal DS pursuant to system A (step
S143). Similarly, if the start timing of transmission pursuant to
system A has arrived, the sensor controller 31 activates
transmission operation of the uplink signal US pursuant to system A
(step S145). If the start timing of reception pursuant to system C
has arrived, the sensor controller 31 activates reception operation
of the downlink signal DS pursuant to system C (step S147).
[0135] Furthermore, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S143 or the step S147 (step S148). If
determining that the downlink signal DS has been received by the
reception operation started in the step S143 (that is, if the
downlink signal DS pursuant to system A has been received), the
sensor controller 31 switches its own operation mode to operation
mode A (step S149). On the other hand, if determining that the
downlink signal DS has been received by the reception operation
started in the step S147 (that is, if the downlink signal DS
pursuant to system C has been received), the sensor controller 31
switches its own operation mode to operation mode C (step S150) and
thereafter determines whether or not function information
(specifically, all or part of the unique ID) indicating that the
stylus 2 is compatible with system A is included in the downlink
signal DS (step S151). If determining that the function information
indicating that the stylus 2 is compatible with system A is not
included in the downlink signal DS, the sensor controller 31 moves
the processing to a step S171 in FIG. 23 and starts normal
operation pursuant to system C. On the other hand, if determining
that the function information is included, the sensor controller 31
moves the processing to a step S181 in FIG. 24 and executes
processing for causing the stylus 2 to make a transition to
operation mode A.
[0136] FIG. 22 depicts operation of the sensor controller 31 after
operation in operation mode A is started. As depicted in this
diagram, the sensor controller 31 detects each of the arrival of
the transmission start timing and the arrival of the reception
start timing (steps S161 and S163). Then, the sensor controller 31
activates transmission operation of the uplink signal US pursuant
to system A (step S162) if the transmission start timing has
arrived, and activates reception operation of the downlink signal
DS pursuant to system A (step S164) if the reception start timing
has arrived.
[0137] Furthermore, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S164 (step S165). If determining that
the downlink signal DS has been received, the sensor controller 31
returns to the step S161 and repeats the processing. On the other
hand, if determining that the downlink signal DS has not been
received, the sensor controller 31 returns its own operation mode
to unsettled mode P (step S166) and returns the processing to the
step S142 in FIG. 21. This processing is executed in order to
return the sensor controller 31 to unsettled mode P when the stylus
2 is separated from the touch surface 3t.
[0138] FIG. 23 depicts operation of the sensor controller 31 after
operation in operation mode C is started. As depicted in this
diagram, the sensor controller 31 detects the arrival of the
reception start timing (step S171). Then, if the reception start
timing has arrived, the sensor controller 31 activates reception
operation of the downlink signal DS pursuant to system C (step
S172).
[0139] Furthermore, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S172 (step S173). If determining that
the downlink signal DS has been received, the sensor controller 31
returns to the step S171 and repeats the processing. On the other
hand, if determining that the downlink signal DS has not been
received, the sensor controller 31 returns its own operation mode
to unsettled mode P (step S174) and returns the processing to the
step S142 in FIG. 21. This processing is executed in order to
return the sensor controller 31 to unsettled mode P when the stylus
2 is separated from the touch surface 3t, similarly to the step
S166 in FIG. 22.
[0140] FIG. 24 depicts operation of the sensor controller 31 when
the function information indicating that the stylus 2 is compatible
with system A (specifically, unique ID indicating that the stylus 2
is compatible with system A) is included in the downlink signal DS
transmitted by the stylus 2 pursuant to system C in the step S151
in FIG. 21. In this case, the sensor controller 31 carries out
operation for causing the stylus 2 to make a transition to
operation mode A as described above.
[0141] Specifically, first the sensor controller 31 detects the
arrival of the reception start timing of the downlink signal DS
pursuant to system C (step S181). Then, if the reception start
timing has arrived, the sensor controller 31 activates reception
operation of the downlink signal DS pursuant to system C (step
S182).
[0142] Furthermore, the sensor controller 31 determines whether or
not transmission of the downlink signal DS has been interrupted
(step S183). The sensor controller 31 carries out this
determination when reception of the downlink signal DS has ended,
and determines that the transmission has been interrupted if, at
the timing, an interval equal to or longer than a predetermined
time exists until the next reception start timing of the downlink
signal DS begins.
[0143] If determining that the transmission has not been
interrupted in the step S183, the sensor controller 31 returns to
the step S181 and continues the processing. On the other hand, if
determining that the transmission has been interrupted, the sensor
controller 31 switches its own operation mode to operation mode A
(step S184) and activates transmission operation of the uplink
signal pursuant to system A (step S185). Then, the sensor
controller 31 determines whether or not the number of times of
transmission by this transmission operation has reached a
predetermined number of times (step S186).
[0144] If determining that the predetermined number of times has
been reached in the step S186, the sensor controller 31 detects the
arrival of the reception start timing of the downlink signal DS
pursuant to system A (step S187). This timing is the timing when
the stylus 2 that has received the uplink signal US pursuant to
system A starts transmission of the downlink signal DS pursuant to
system A. If the reception start timing has arrived, the sensor
controller 31 activates reception operation of the downlink signal
DS pursuant to system A (step S188).
[0145] Subsequently, the sensor controller 31 determines whether or
not the downlink signal DS has been received by the reception
operation started in the step S188 (step S189). If determining that
the downlink signal DS has been received, the sensor controller 31
switches its own operation mode to operation mode A (step S192) and
thereafter moves the processing to the step S161 in FIG. 22.
Thereby, communication pursuant to system A is started between the
stylus 2 and the sensor controller 31.
[0146] If determining that the predetermined number of times has
not been reached in the step S186 or if determining that the
downlink signal DS has not been received in the step S189, the
sensor controller 31 switches its own operation mode to operation
mode C (step S190). Then, the sensor controller 31 determines
whether or not the number of times the reception operation in the
step S188 is attempted has reached a predetermined number of times
(step S191), and moves the processing to the step S171 in FIG. 23
if determining that the predetermined number of times has been
reached. This is equivalent to the case in which the downlink
signal DS pursuant to system A is not received indefinitely and
thus the sensor controller 31 abandons communication pursuant to
system A, and communication pursuant to system C is started between
the stylus 2 and the sensor controller 31. On the other hand, if
determining that the predetermined number of times has not been
reached in the step S191, the sensor controller 31 returns to the
step S181 and continues the processing.
[0147] As described above, also with the method carried out by the
stylus 2 according to the present embodiment, the stylus 2 can
activate reception operation of a signal pursuant to system A
immediately after contacting the touch surface 3t. Therefore, it
becomes possible to shorten the time from the contact with the
touch surface 3t to setting the stylus 2 to operation mode A.
[0148] Furthermore, according to the method carried out by the
stylus 2 and the sensor controller 31 in accordance with the
present embodiment, even when the operation mode of the stylus 2 is
operation mode C, in which unidirectional transmission of a signal
pursuant to system C is carried out, the operation mode of the
stylus 2 can be switched to operation mode A by an instruction
(specifically, transmission of the uplink signal US pursuant to
system A) by the sensor controller 31 that has determined that the
stylus 2 is compatible with system A. Therefore, it becomes
possible to start communication pursuant to system A between the
stylus 2 and the sensor controller 31.
[0149] Next, a third embodiment of the present disclosure will be
described. The stylus 2 according to the present embodiment is
different from the stylus 2 according to the first and second
embodiments in that the stylus 2 is allowed to control the contents
of indication by the indicator 26 according to its own operation
mode. The other points and the configuration of the sensor
controller 31 are the same as the first or second embodiment.
Therefore, the description will be made with focus on the different
point in the following.
[0150] The signal processor 24 of the stylus 2 according to the
present embodiment controls the indicator 26 to carry out
indication differently depending on the operation mode decided, as
described in the first and second embodiments. That is, the
indicator 26 is controlled to carry out indication differently
between the case in which operation is carried out in the first
operation mode in which a signal pursuant to the first system is
transmitted, and the case in which operation is carried out in the
second operation mode in which a signal pursuant to the second
system is transmitted. Furthermore, the indicator 26 is controlled
to carry out indication differently from both the first and second
operation modes at the stage before it is decided whether operation
is to be carried out in the first operation mode or operation is to
be carried out in the second operation mode, i.e. in the case of
carrying out operation in the above-described unsettled mode.
According to this, for example in the signal processor 24 in the
case of receiving the uplink signal US pursuant to the first
system, its own operation mode is set to be the first operation
mode. This causes the signal processor 24 to control the indicator
26 to carry out the indication corresponding to the first operation
mode.
[0151] If the operation mode of the stylus 2 is switched every time
the uplink signal US or the writing pressure is detected as
described in the first and second embodiments, it becomes difficult
for the user to understand which operation mode the stylus 2 is
currently operating in. For example, when the electronic equipment
3 and the stylus 2 do not function despite that they are supposed
to be in the same operation mode, or the like, it is impossible to
understand what is happening. The stylus 2 according to the present
embodiment allows the user to know which operation mode the stylus
2 (and sensor controller 31) is currently operating in by checking
the indicator 26.
[0152] As concrete contents of indication by the indicator 26,
various contents are conceivable. For example, if the indicator 26
is a light emitting diode that can emit light with plural colors,
it is conceivable that the contents of indication by the indicator
26 are controlled in such a manner that the indicator 26 is lit up
with colors different for each operation mode as follows for
example: the indicator 26 is lit up with red in unsettled mode P
and lit up with blue in the first operation mode and lit up with
green in the second operation mode. Furthermore, if the indicator
26 is a light emitting diode that can emit light with a single
color, it is conceivable that the contents of indication by the
indicator 26 are controlled by combining blinking on and off as
follows for example. Specifically, in unsettled mode P, the
indicator 26 is repeatedly turned on and off at a predetermined
cycle. In the first operation mode, the indicator 26 is turned on
and off twice, at an interval shorter than the above-described
predetermined cycle at the timing of switching to the first
operation mode, and thereafter is kept off. In the second operation
mode, the indicator 26 is turned on and off only once, at the
timing of switching to the second operation mode, and thereafter is
kept off.
[0153] Although preferred embodiments of the present disclosure are
described above, the present disclosure is not limited to these
embodiments at all and it is obvious that the present disclosure
can be carried out in various modes without departing from the gist
thereof.
[0154] For example, in the above-described embodiments, the stylus
2 receives the uplink signal US through the electrode 21 (FIG. 1).
However, the stylus 2 may receive the uplink signal US by a
separate wireless communication measure such as Bluetooth
(registered trademark) for example. Furthermore, it suffices for
the uplink signal US (signal pursuant to the first system) to be a
signal that can be detected by the stylus 2, which includes the
case in which the sensor controller 31 that carries out detection
of a finger touch using mutual capacitance between transmitting
electrode and receiving electrode uses a transmission signal
supplied to the transmitting electrode as the uplink signal US.
[0155] Furthermore, in the above-described embodiments, if the
signal that should be received is not received after the start of
operation in a certain operation mode, the stylus 2 and the sensor
controller 31 immediately return to unsettled mode P (step S26 in
FIG. 9, step S38 in FIG. 10, step S66 in FIG. 12, step S78 in FIG.
13, step S126 in FIG. 19, step S166 in FIG. 22, step S174 in FIG.
23). However, instead of immediately returning to unsettled mode P,
the stylus 2 and the sensor controller 31 may return to unsettled
mode P if failure in reception occurs a predetermined number of
times, for example.
[0156] In the above-described embodiments, switching between plural
systems in an optimizing manner is described. However, it is
obvious that the present disclosure can be applied also to the case
of switching from an operation mode in which equipment operates in
an old version as the second system to another operation mode in
which equipment operates in a newer version by using function
information.
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