U.S. patent application number 10/405368 was filed with the patent office on 2004-10-14 for mobile terminal.
Invention is credited to Hasegawa, Tsukasa, Ikuta, Katsuki, Ito, Tamotsu, Kuroda, Masayoshi.
Application Number | 20040204022 10/405368 |
Document ID | / |
Family ID | 29388481 |
Filed Date | 2004-10-14 |
United States Patent
Application |
20040204022 |
Kind Code |
A1 |
Ito, Tamotsu ; et
al. |
October 14, 2004 |
Mobile terminal
Abstract
There is provided a cellular phone taking into consideration
enhancement in processing speed and reduction in current
consumption, and the cellular phone comprises a processing unit
capable of executing plural kinds of processing, an oscillator for
generating a clock signal to be fed to the processing unit, and a
clock controller for converting the frequency of the clock signal
received from the oscillator, wherein the clock controller changes
the frequency of the clock signal for each of the plural kinds of
the processing in response to the control by the central processing
unit.
Inventors: |
Ito, Tamotsu; (Ayase,
JP) ; Ikuta, Katsuki; (Hachioji, JP) ; Kuroda,
Masayoshi; (Yokohama, JP) ; Hasegawa, Tsukasa;
(Hiratsuka, JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET
SUITE 1800
ARLINGTON
VA
22209-9889
US
|
Family ID: |
29388481 |
Appl. No.: |
10/405368 |
Filed: |
April 3, 2003 |
Current U.S.
Class: |
455/550.1 ;
455/552.1 |
Current CPC
Class: |
Y02D 70/40 20180101;
H04M 1/725 20130101; H04B 1/40 20130101; H04W 52/029 20130101; Y02D
30/70 20200801 |
Class at
Publication: |
455/550.1 ;
455/552.1 |
International
Class: |
H04M 001/00; H04B
001/38 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2002 |
JP |
2002-100735 |
Claims
What is claimed is:
1. A mobile terminal comprising: an antenna which transmits and
receives radio waves; a transmit/receive unit connected with the
antenna; an audio signal input unit which receives audio signals;
an audio signal output unit which delivers audio signals; a central
processing unit capable of executing plural kinds of processing; a
display unit which displays under control by the central processing
unit; an oscillator which generates a clock signal to be fed to the
central processing unit; and a clock controller which converts the
frequency of the clock signal received from the oscillator, wherein
the clock controller changes the frequency of the clock signal for
each of the plural kinds of the processing in response to the
control by the central processing unit.
2. A mobile terminal according to claim 1, further comprising a
directive input unit which enters a directive from a user, wherein
when the user enters a request for change in processing speed or
change in frequency from the directive input unit, the central
processing unit controls the clock controller so as to change the
frequency of the clock signal.
3. A mobile terminal according to claim 1, wherein when the
frequency of the clock signal is changed by the clock controller,
the central processing unit controls the display unit so as to
exhibit a display concerning the change.
4. A mobile terminal according to claim 3, wherein the display unit
exhibits a display corresponding to the magnitude of the frequency
of the clock signal by use of a graphics or an image.
5. A mobile terminal according to claim 1, further comprising a
memory that stores information concerning the frequency of the
clock signal corresponding to each of the plural kinds of the
processing, and the central processing unit controls the clock
controller in response to the information stored in the memory.
6. A mobile terminal according to claim 1, wherein the central
processing unit controls the clock controller in such a way as to
lower the frequency of the clock signal when the amount of the
battery capacity that remains in a battery becomes small.
7. A mobile terminal according to claim 1, further comprising a
memory that stores a control program, wherein the central
processing unit execute processing in accordance with the control
program stored in the memory.
8. A mobile terminal comprising: an antenna for transmitting and
receiving radio waves; a transmit/receive unit connected with the
antenna; a first processing unit for controlling transmit/receive
of signals by the transmit/receive unit; a second processing unit
for executing processing of a plurality of application programs; an
oscillator for generating a clock signal to be fed to the first
processing unit and the second processing unit, respectively; and a
clock controller for converting the frequency of the clock signal
received from the oscillator, wherein the clock controller can
change the frequency of the clock signal to be fed to the second
processing unit for each of the plurality of the application
programs.
9. A mobile terminal according to claim 8, further comprising a
directive input unit for entering a directive from a user, wherein
when the user enters a request for change in processing speed or
change in frequency from the directive input unit, the central
processing unit changes the frequency of the clock signal to be fed
to the second processing unit.
10. A mobile terminal according to claim 8, wherein the clock
controller controls the frequency of the clock signal so as to
become lower when the amount of the battery capacity that remains
in a battery becomes small.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a cellular phone comprising
a central processing unit (CPU).
[0002] A hand-held terminal or mobile terminal, for switching the
frequency of a clock signal delivered from the side of an
application program, is disclosed in JP-A NO. 73237/1999 (Heisei
11).
[0003] Further, in JP-A No. 148475/2000, there is disclosed a
computer for a mobile unit, capable of switching a clock frequency
to a high-speed mode frequency higher than a normal frequency when
conditions, such as power source voltage, ambient temperature, and
so forth, are satisfied.
[0004] In the case of the conventional technology described above,
speed control of a clock signal has been implemented by an
application program or has been dependent on the conditions such as
power source voltage, ambient temperature, and so forth, so that
there is no room for interposition of the will of a user in
switching the speed of the clock signal. Further, if the CPU is
driven at a high frequency, there has been a tendency toward an
increase in current consumption although a processing speed is
enhanced. With a cellular phone, in particular, since its battery
capacity is small, there has been a risk of premature depletion of
the battery capacity occurring when the clock signal has been
automatically switched over to the high-speed side without
knowledge of the user.
SUMMARY OF THE INVENTION
[0005] To attain both enhancement in processing speed and reduction
in current consumption, it is an object of the invention to provide
a mobile terminal comprising clock control means capable of
changing the frequency of a clock signal received from an
oscillator under control by a central processing unit, and
converting an operation frequency of the central processing unit to
a different frequency, wherein a clock signal at the different
frequency as converted by the clock control means becomes a clock
signal of the central processing unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a block diagram showing the configuration of a
first embodiment of a cellular phone according to the
invention;
[0007] FIG. 2 is a block diagram showing the configuration of a
second embodiment of a cellular phone according to the
invention;
[0008] FIG. 3 is a block diagram showing the configuration of a
third embodiment of a cellular phone according to the
invention;
[0009] FIG. 4 is a block diagram showing the configuration of a
fourth embodiment of a cellular phone according to the invention;
and
[0010] FIG. 5 is a graph showing the relationship between an
operation frequency of a central processing unit of the cellular
phone according to the first to fourth embodiments, respectively,
and current consumption.
[0011] Other and further objects, features and advantages of the
invention will appear more fully from the following
description.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] A first embodiment of a cellular phone according to the
invention is described hereinafter with reference to FIGS. 1 and 5.
FIG. 1 is a block diagram showing the internal configuration of the
cellular phone according to the first embodiment.
[0013] A central processing unit (CPU) 100 controls the operation
of the cellular phone in accordance with a control program stored
in a memory 110. The CPU 100 performs operation in accordance with
an input pushbutton as pressed via an operation panel (input
pushbutton group) 120, executing processing in response to the
input pushbutton as pressed.
[0014] Upon dialing, a telephone number as inputted from the
operation panel 120 is shown on a display unit 130, a speech signal
delivered from a speech input unit (microphone) 140 is sent out in
the form of radio waves from an antenna 160 to the outside via a
transmit/receive unit 150 in accordance with a transmission
directive delivered from the operation panel 120.
[0015] At the time of signal reception, radio waves from the
outside are received by the antenna 160, and upon recognition by
the transmit/receive unit 150 that the radio waves received are
radio waves corresponding to a telephone number dedicated to the
present cellular phone, speech is delivered from a speech output
unit (speaker) 170.
[0016] The CPU 100 receives a clock signal from an oscillator 180
through the intermediary of a clock controller 200. Because an
operation frequency of the CPU 100 is dependent on the frequency of
the clock signal as received, a processing speed of the CPU 100 is
regulated by the frequency of the clock signal. The clock
controller 200 converts the frequency of the clock signal into any
suitable frequency by use of a PLL (Phase Locked Loop) circuit
under control by the CPU 100, and the clock signal is delivered to
the CPU 100 as a clock signal of the CPU 100. The frequency of the
clock signal delivered to the CPU 100 becomes the operation
frequency of the CPU 100.
[0017] FIG. 5 is a graph showing the relationship between the
operation frequency and current consumption. In proportion as the
frequency of the clock signal is changed to a higher frequency, the
operation frequency of the CPU 100 becomes higher, thereby
enhancing the processing speed of the CPU 100 although current
consumption increases.
[0018] With the present embodiment, when executing a specific
processing, the frequency of the clock signal of the CPU 100 is
caused to change to a higher frequency, thereby enhancing the
processing speed. Upon completion of the execution of the specific
processing, the frequency of the clock signal of the CPU 100 is
caused to change to a lower frequency, thereby reducing current
consumption. In the initial condition at the time when power is
turned on, the frequency of the clock signal of the CPU 100 is set
to a low frequency in order to reduce current consumption.
[0019] Herein, the specific processing refers to, for example,
processing for image decoding, address retrieval processing, and
application processing such as kana-kanji conversion processing
used in entering characters. These processing often have effects on
the response of the user.
[0020] With the present embodiment, the user can change the
operation frequency of the CPU 100 by changing the output frequency
of the clock controller 200 at will with the use of a clock
manipulation unit 300 connected with the CPU 100.
[0021] If the user enters a request for change via the clock
manipulation unit 300, the CPU 100 receives an input from the clock
manipulation unit 300, and controls the clock controller 200,
thereby controlling a clock frequency to be fed to the CPU 100.
That is, in response to the input from the clock manipulation unit
300, the frequency of the clock signal to be fed to the CPU 100 is
set.
[0022] Further, with the present embodiment, depending on an
application to be used, and use environments, the user can change
the frequency of the clock signal in every processing. For example,
if the user wants to increase the processing speed of the CPU 100,
the frequency of the clock signal can be raised, and if the user
wants to reduce current consumption, the frequency of the clock
signal can be changed to a lower frequency. By virtue of such a
function as described, the user can set the frequency of the clock
signal as appropriate at will depending on the user's use
environments, such as the user desire to execute high speed
processing, or to use the cellular phone for many hours, the amount
of the actual battery capacity that remains in a battery being
small, and so forth, so that operability can be enhanced.
[0023] In FIG. 1, the clock manipulation unit 300 is shown as a
single pushbutton (clock manipulation pushbutton), but may be made
up of a plurality of keys instead. In order to implement the clock
manipulation unit 300 with the single pushbutton, for example, the
lowest frequency is set as the initial condition of the frequency
of the clock signal, thereby carrying out control such that every
time when the single pushbutton is once operated, the frequency of
the clock signal of the CPU 100 is changed to sequentially higher
frequencies by stages. The frequency is changed cyclically, and if
the frequency of the clock signal of the CPU 100 is changed to the
highest frequency, upon operation of the single pushbutton the next
time, the frequency of the clock signal of the CPU 100 reverts to
the lowest frequency. Thus, every time when the single pushbutton
is operated, the output frequency of the clock controller 200 can
be changed, thereby enabling the operation frequency of the CPU 100
to be changed.
[0024] The CPU 100 causes the display unit 130 to display a
numerical value of the frequency after changed in such a way as to
explicitly advise the user of the frequency of the clock signal
after changed. Since it is sufficient for such display to indicate
simply which stage the processing speed of the CPU 100 is in,
indication of a specific numerical value of the frequency is not
necessarily required. Numbers to indicate respective stages, such
as 1, 2 , 3 . . . , or characters such as high, middle, low, etc.
may be displayed. Alternatively, the respective stages of the
processing speed may be displayed in number of stars, exhibiting
one star on the display unit 130 for the lowest speed, increasing
the number of stars exhibited on the display unit 130 in ascending
order of the stage. Otherwise, the status of the processing speed
may be displayed with the use of a bar graph, icons, and so
forth.
[0025] Further, for changing the output frequency of the clock
controller 200 at the user's will, there may be adopted a method
whereby an operation menu directing change of the frequency of the
clock signal is caused to be displayed on the display unit 130
without the use of the clock manipulation pushbutton, and the user
selects or directs at will the output frequency of the clock
controller 200 by use of the operation panel 120, thereby changing
the operation frequency of the CPU 100. In such a case, the
operation panel 120 functions as the clock manipulation unit 300,
so that the clock manipulation unit 300 can be omitted.
[0026] Now, a second embodiment of a cellular phone according to
the invention is described hereinafter with reference to FIG. 2.
FIG. 2 is a block diagram showing the internal configuration of the
cellular phone according to the second embodiment.
[0027] With the present embodiment, a central processing unit (CPU)
is made up so as to be divided into a first central processing unit
400 concerned with transmit/receive of signals, and a second
central processing unit 410 handling processing that has effects on
the response of a user. In FIG. 2, blocks denoted by the same
reference numerals as those in FIG. 1 correspond to those blocks of
the first embodiment, having the same functions.
[0028] The first central processing unit 400 controls operation
concerned with transmit/receive by the cellular phone in accordance
with a control program stored in a first memory 420, and the second
central processing unit 410 controls operation concerned with
processing that has effects on the response of a user in accordance
with a control program stored in a second memory 430. More
specifically, the second central processing unit 410 controls
operation concerned with processing of an application program.
[0029] A clock signal from an oscillator 180 is directly delivered
to the first central processing unit 400 as a clock signal.
Meanwhile, a clock signal at any suitable frequency converted by
control of the second central processing unit 410 is delivered to
the second central processing unit 410 through the intermediary of
a clock controller 200.
[0030] With such a configuration as described, when executing a
specific processing, the frequency of the clock signal delivered to
the second central processing unit 410 can be changed to a high
frequency, thereby enhancing a processing speed, and upon
completion of execution of the processing that has effects on the
response of the user, the frequency of the clock signal delivered
to the second central processing unit 410 can be changed to a low
frequency, thereby reducing current consumption.
[0031] For example, during a standby (waiting) period for
communications by the cellular phone, the first central processing
unit 400 is in intermittent operation to receive radio waves from
the outside via an antenna 160, executing processing for
recognition by the transmit/receive unit 150 that the radio waves
received are radio waves corresponding to a telephone number
dedicated to the present cellular phone. In this case, the
frequency of the clock signal delivered to the second central
processing unit 410 is changed to a low frequency to thereby reduce
current consumption. As shown FIG. 5, the relationship between an
operation frequency and current consumption is such that in
proportion as the operation frequency becomes higher, the current
consumption increases while in proportion as the operation
frequency becomes lower, the current consumption decreases.
[0032] The cellular phone shown in FIG. 2 further comprises a power
supply controller 500. The power supply controller 500 controls
power to be supplied from a battery 510 to the second central
processing unit 410 in response to control by the first central
processing unit 400. For example, during a standby (waiting) period
for communications by the cellular phone or upon completion of the
processing by the second central processing unit 410, the power
supply controller 500 can turn off power to be supplied to the
second central processing unit 410 in response to control by the
first central processing unit 400. Since the second central
processing unit 410 handles application, its power consumption at
the time of processing is large, and consequently, effective saving
in power can be attained by controlling the power supplied.
[0033] Next, a third embodiment of a cellular phone according to
the invention is described hereinafter with reference to FIG.
3.
[0034] The cellular phone shown in FIG. 3 comprises a battery
voltage detector 600 in place of the power supply controller 500
incorporated in the cellular phone shown in FIG. 2. In FIG. 3,
blocks denoted by the same reference numerals as those in FIG. 2
have the same functions as those of the blocks of the second
embodiment, omitting therefore description thereof.
[0035] The battery voltage detector 600 detects a voltage of a
battery 510. A first central processing unit 400 determines whether
or not the voltage detected is lower than a predetermined value. In
the case where it is determined that the amount of the actual
battery capacity that remains in the battery 510 is less than a
predetermined amount, the frequency of a clock signal delivered to
a second central processing unit 410 is changed to a lower
frequency even when executing a specific processing, thereby
reducing current consumption. Hence, it is possible to effect
control so as to reduce current consumption in case that the amount
of the actual battery capacity that remains in the battery becomes
small, thereby prolonging operable time of the cellular phone.
[0036] Further, a fourth embodiment of a cellular phone according
to the invention is described hereinafter with reference to FIG. 4.
FIG. 4 is a block diagram showing the internal configuration of the
cellular phone of a folded structure, according to the fourth
embodiment. In FIG. 4, blocks denoted by the same reference
numerals as those in FIGS. 2 and 3, respectively, have the same
functions as those of the blocks of the second and third
embodiments, respectively, omitting therefore description
thereof.
[0037] The cellular phone shown in FIG. 4 comprises a folding
condition detector 700 for detecting whether the cellular phone is
in a folded (closed) condition or in an unfolded (open)
condition.
[0038] With the cellular phone according to the present embodiment,
a first display unit 710 and a second display unit 720 are added to
a first central processing unit 400 and a second central processing
unit 410, respectively. The first display unit 710 is disposed at a
position as can be seen by a user even in the folded condition. The
second display unit 720 is disposed at the folded-down side of the
cellular phone.
[0039] Since the operation of the cellular phone in the open
condition is the same as that of the cellular phone according to
the second and third embodiments, respectively, the operation of
the cellular phone in the closed condition is described
hereinafter.
[0040] Normally, in the closed condition, the cellular phone is
often on standby (waiting) for cellular phone communications, and
the first central processing unit 400 is in intermittent operation
to receive radio waves from the outside via an antenna 160,
executing processing for recognition through the intermediary of a
transmit/receive unit 150 that the radio waves received are radio
waves corresponding to a telephone number dedicated to the present
cellular phone. Meanwhile, since a load on the second central
processing unit 410 is light at this point in time, the frequency
of a clock signal delivered to the second central processing unit
410 can be changed to a low frequency, thereby reducing power
consumption. When executing a specific processing even in the
closed condition, the frequency of the clock signal delivered to
the second central processing unit 410 is caused to change to a
higher frequency, thereby enhancing a processing speed, and upon
completion of execution of the specific processing, the frequency
of the clock signal is caused to change to a low frequency, thereby
reducing current consumption.
[0041] Further, in the closed condition, the user is unable to see
the second display unit 720. Accordingly, as for processing
concerning the second display unit 720, upon detection of the
closed condition, the frequency of the clock signal delivered to
the second central processing unit 410 is caused to change to a low
frequency, thereby enabling current consumption to be reduced.
[0042] Furthermore, even when executing the specific processing,
the frequency of the clock signal delivered to the second central
processing unit 410 may be changed to a low frequency in the case
of the closed condition. In the case of the cellular phone being in
the closed condition, the user does not look at a display screen of
the cellular phone, and is often in no hurry to do processing.
Accordingly, in the case of the closed condition, processing can be
executed while reducing power consumption by changing the frequency
of the clock signal to a lower frequency. When the cellular phone
is shifted to the open condition, the processing speed is enhanced
by changing the frequency of the clock signal delivered to the
second central processing unit 410 to a higher frequency.
[0043] The cellular phone shown in FIG. 4 further comprises a
lighting controller 800 for controlling backlight of the second
display unit 720. Since the user is unable to see the second
display unit 720 in the folded condition, further reduction in
power consumption can be attained by turning off the backlight of
the second display unit 720.
[0044] In addition, the power supply controller 500 shown in FIG. 2
or the battery voltage detector 600 shown in FIG. 3 may be added to
the cellular phone according to the present embodiment. In such a
case, when the amount of the actual battery capacity that remains
in the battery 510 is less than a predetermined amount, power
consumption can be reduced and waiting time can be extended by
implementing control such that the backlight of the second display
720 is turned off even in the open condition.
[0045] Still further, the operability of the cellular phone can be
improved by providing the cellular phone shown in FIGS. 2 through
4, respectively, with the clock manipulation unit 300 shown FIG. 1,
thereby enabling the user to change the frequency of the clock
signal as with the case of the first embodiment. Also, the
operation panel 120 may have the function of the clock manipulation
unit 300.
[0046] The respective embodiments described hereinbefore may be
carried out singly or in combination as appropriate.
[0047] With the embodiments described hereinbefore, the clock
controller, the memories, and so forth are disposed outside of the
central processing unit, however, these components together with
the central processing unit may be integrated so as to be
incorporated in one chip.
[0048] As described in the foregoing, with the embodiments of the
invention, it is possible to attain both enhancement in the
processing speed and reduction in the power consumption.
[0049] The foregoing invention has been described in terms of
preferred embodiments. However, those skilled, in the art will
recognize that many variations of such embodiments exist. Such
variations are intended to be within the scope of the present
invention and the appended claims.
* * * * *