U.S. patent number RE41,686 [Application Number 09/659,042] was granted by the patent office on 2010-09-14 for electronic watch.
This patent grant is currently assigned to Citizen Holdings Co., Ltd.. Invention is credited to Kenji Fujita, Kiyotaka Igarashi, Isamu Kobayashi, Akiyoshi Murakami.
United States Patent |
RE41,686 |
Fujita , et al. |
September 14, 2010 |
Electronic watch
Abstract
In an electronic watch having an electrical generation means, an
electrical power storage means which stores electrical energy
generated by the electrical generation means, an oscillator
circuit, a control section which operates in response to a clock of
the oscillator circuit, and a display section which is controlled
by the control section, and which displays the time and also
selectively displays a function other than the time, a voltage
detection means which detects the voltage of the electrical power
storage means and a control section management means which, in
response to a detection signal from the voltage detection means
controls the operation of the control section are provided, and
hysteresis is provided between the operation starting point and
operation ending point of the control section, which control such
operations as storage of hand positions.
Inventors: |
Fujita; Kenji (Tokyo,
JP), Kobayashi; Isamu (Tokyo, JP),
Igarashi; Kiyotaka (Tokyo, JP), Murakami;
Akiyoshi (Tokyo, JP) |
Assignee: |
Citizen Holdings Co., Ltd.
(Tokyo, JP)
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Family
ID: |
26538141 |
Appl.
No.: |
09/659,042 |
Filed: |
September 7, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
08721614 |
Sep 26, 1996 |
05889736 |
Mar 30, 1999 |
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Foreign Application Priority Data
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Sep 26, 1995 [JP] |
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247209/1995 |
Sep 26, 1995 [JP] |
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247210/1995 |
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Current U.S.
Class: |
368/66; 368/80;
368/204 |
Current CPC
Class: |
G04C
10/04 (20130101); G04C 10/00 (20130101) |
Current International
Class: |
G04B
9/00 (20060101); G04B 19/04 (20060101); G04C
23/00 (20060101) |
Field of
Search: |
;368/64,66,80,82,203-205 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 591 557 |
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Apr 1994 |
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EP |
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0 766 150 |
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Apr 1997 |
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EP |
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51-121368 |
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Oct 1976 |
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JP |
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61-176878 |
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Aug 1986 |
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JP |
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61-202186 |
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Sep 1986 |
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JP |
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61-280595 |
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Dec 1986 |
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JP |
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62-16492 |
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Jan 1987 |
|
JP |
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62-46390 |
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Mar 1987 |
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JP |
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62-194484 |
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Aug 1987 |
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JP |
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62-194484 |
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Aug 1987 |
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JP |
|
63-88790 |
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Jun 1988 |
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JP |
|
68 148193 |
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Jun 1988 |
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JP |
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63-223588 |
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Sep 1988 |
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JP |
|
03-269281 |
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Nov 1991 |
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JP |
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4-78594 |
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Jul 1992 |
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JP |
|
05-264751 |
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Oct 1993 |
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JP |
|
7-46145 |
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Feb 1995 |
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JP |
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WO 93/22712 |
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Nov 1993 |
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WO |
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Primary Examiner: Miska; Vit W
Attorney, Agent or Firm: Scully, Scott, Murphy &
Presser, P.C.
Claims
What is claimed is:
1. In an electronic watch having an electrical power generator
means for generating electrical power, an electrical power storage
means for storing electrical power generated by said electrical
power generating means, an oscillator circuit for producing an
output signal, a time-signal generating means for generating a
time-signal output in response to the output signal from said
oscillator circuit, and a time display which displays time
information.Iadd., .Iaddend.responsive to said time-signal output
from said time-signal generating means, with a plurality of time
indicating hands, an improvement further comprising: a control
section for switching a display of a condition about said
electronic watch on said time display; a voltage detection means
for detecting the voltage of said electrical power storage means
and for producing an output detection signal; .[.and.]. a control
section management means for controlling the operation of said
control section in response to the detection signal of the voltage
detection means, wherein said control section causes at least one
time hand of the plurality of time indicating hands in said time
display to move to and to stop at a pre-established position
without performing any mechanical operation when the value of said
detected voltage drops below a predetermined reference value,
during said time display displaying time information, so as to
indicate such voltage drop.Iadd.; wherein when said electronic
watch assumes a first status, said control section causes at least
one time hand of the plurality of time indicating hands in said
time display to move and to stop at a first pre-established
stopping position which indicates a charge warning state of said
electrical power generator means, and when said electronic watch
assumes a second status, said control section causes said at least
one time hand to move and to stop at a second pre-established
stopping position which indicates that the timekeeping function of
said electronic watch is stopped.Iaddend..
.[.2. An electronic watch according to claim 1, wherein said
control section causes at least one time hand of the plurality of
time indicating hands in said time display to move and to stop at a
plurality of pre-established positions..].
.[.3. An electronic watch according to claim 2, wherein when said
electric watch assumes a first status, said at least one time hand
stops at a first stopping position, and when said electric watch
assumes a second status, said at least one time hand stops at a
second stopping position..].
.[.4. An electronic watch according to claim 3, wherein said first
stopping position is a position which indicates a charge warning
state of said electrical power generator means, and wherein said
second stopping position is a position which indicates that the
timekeeping function of said electronic watch is stopped..].
5. An electronic watch according to claim .[.4.]. .Iadd.1.Iaddend.,
wherein said control section causes at least one time hand of the
plurality of time indicating hands in said time display to also
move and to stop at a third stopping position which indicates that
the minute and hour hands and the time of the timekeeping circuit
differ from each other.
6. An electronic watch according to claim 1, wherein said
electrical power generator means and said electrical power storage
means form an electrical generation means, and wherein said voltage
detection means detects an output voltage of said electrical
generation means.
7. .[.In an.]. .Iadd.An .Iaddend.electronic watch
.Iadd.comprising:.Iaddend. .[.having.]. an electrical generator
means for generating electrical power.[.,.]. .Iadd.;.Iaddend. an
electrical power storage means for storing electrical power
generated by said electrical power generating means.[.,.].
.Iadd.;.Iaddend. .[.an oscillator circuit including a clock for
producing an output signal, a control section which operates in
response to the clock of said oscillator circuit, and a time
display which is controlled by said control section and which
displays time and also selectively displays a function other than
time, an improvement further comprising a voltage detection means
for detecting the voltage of said electrical power storage means,
said electronic watch having a first mode in which the function
other than time is displayed, based upon a detected voltage value
of said voltage detection means, and a second mode in which the
function other than time is not displayed, based upon a detected
voltage value of said voltage detection means, and a hysteresis is
provided between the occurrence of a transition from the first mode
to the second mode and the occurrence of a transition from the
second mode to the first mode.]. .Iadd.a control means; and a time
display which is controlled by said control means and which
displays time information and also selectively displays a function
other than said time information, an improvement further comprising
a voltage detection means for detecting the voltage of said
electrical power storage means and for generating an output signal
corresponding to said detected voltage, wherein said electronic
watch having a first mode in which said time information and said
function other than said time information is displayed, based upon
a first voltage value detected by said voltage detection means, and
a second mode in which only said time information is displayed,
based upon said first voltage value detected by said voltage
detection means, and further wherein said electronic watch being
configured so that said control means switches the electronic watch
from said first mode to said second mode in response to the output
signal corresponding to said first voltage value of said voltage
detection means, and switches the electronic watch from said second
mode to said first mode in a case when said output signal
corresponding to said first voltage value of said voltage detection
means is outputted continuously for a predetermined period of
time.Iaddend..
8. An electronic watch according to claim 7, wherein said
electrical power generator means and said electrical power storage
means form an electrical generation means, and wherein said voltage
detection means detects an output voltage of said electrical
generation means.
.Iadd.9. An electronic watch according to claim 7, wherein said
electronic watch further provided with a third mode, and wherein, a
transition from said second mode to said third mode is performed at
a second voltage being lower than said first voltage, further
wherein, a transition from said third mode to another mode other
than said third mode is performed at a third voltage which is lower
than said first voltage but higher than said second
voltage..Iaddend.
.Iadd.10. An electronic watch according to claim 7, wherein said
electronic watch is further provided with a chronological function
as a function other than a current time information display
function..Iaddend.
.Iadd.11. An electronic watch according to claim 9, wherein said
electronic watch is further configured so that in said third mode,
said control means performs to display information on a time
information display indicating said user a fact that the time
display function has been stopped..Iaddend.
.Iadd.12. An electronic watch according to claim 9, wherein said
electronic watch is further configured so that in response to said
third voltage, said control means performs a transition from said
third mode to a fourth mode which urges said user of the electronic
watch to correct said time information utilizing said time
display..Iaddend.
.Iadd.13. An electronic watch comprising: a. an electrical power
generator for generating electrical power; b. an electrical power
storage for storing electrical power generated by said electrical
power generator; c. an oscillator circuit for producing an output
signal; d. a time signal generator for generating a time signal
output in response to the output signal from said oscillator
circuit; e. a display, responsive to said time signal output from
said time signal generator, for displaying time information with a
plurality of time indicating hands; f. voltage detector for
detecting a voltage of the electronic watch and for producing an
output detection signal based upon said detected voltage value; g.
a control section, responsive to the output detection signal of the
voltage detector, for causing at least one of the time indicating
hands in said time display to stop at a pre-established position in
said time display, and which show a condition related to the
voltage charge of the electronic watch, when the value of said
detected voltage drops below a predetermined reference voltage
value; h. wherein when said electronic watch assumes a first
status, said control section causes the at least one time
indicating hand in said time display to stop at a first stopping
position which indicates a charge warning state of said power
storage means, and when said electronic watch assumes a second
status, said control section causes said at least one time
indicating hand to stop at a second stopping position which
indicates that the timekeeping function of the electronic watch is
in a stopped state..Iaddend.
.Iadd.14. An electronic watch according to claim 13, wherein said
control section causes said at least one time indicating hand to
stop at a third stopping position which indicates that the
timekeeping function of the electronic watch has been stopped and
that the plurality of time indicating hands can now be
reset..Iaddend.
.Iadd.15. An electronic watch according to claim 13, wherein said
electrical power generator and said electrical power storage form
an electrical generation means, and wherein said voltage detector
detects an output voltage of said electrical generation
means..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic watch, and more
specifically it relates to an electronic watch having an internal
electrical generating mechanism, and in particular an electronic
watch which also has a chronograph function.
2. Description of the Related Art
In the past multifunction electronic watches having not only a time
function, but also a such functions as a chronograph function and
alarm function have been developed and manufactured. These
multifunction electronic watches differ, depending upon watch
functions are added to the time function, and for this reason an
internal microcomputer has been used, enabling a change in the
specifications for various different products.
In a multifunction watch such as this, because it is necessary to
have a single hand indicate a variety of elements, for example, the
current time and the alarm time, a hand position counter is caused
to coincide with, for example, a current time counter, so as to
achieve an indication by means of the hand.
For this reason, it was necessary to first perform the operation of
causing the hand position to coincide with the hand position
counter, this being known as the reference position adjustment
operation.
This reference position adjustment operation needed to be performed
each time the internal circuit took on an indeterminate state
because of, for example, battery replacement, and was extremely
troublesome.
As a method of solving this problem, an electronic watch was
disclosed by the applicant in Japanese Patent Application No.
5-517803, in which, when a decrease in the battery voltage is
detected, the contents of a hand position counter are saved in a
non-volatile memory, these contents being transformed to the hand
position counter after battery replacement, thereby eliminating the
need for hand setting.
In the past an electronic watch has been developed and manufactured
which has an electrical generating mechanism such as a solar cell
and an electric power storage means such as an electric two layered
condenser or a secondary cell, thereby eliminating the need for
battery replacement. These watches, not requiring battery
replacement, were extremely convenient.
A supply in the form of the above-noted electrical power generation
means such formed by an electrical generating means and electric
power storage means exhibit a wide variation in voltage, and can
sometimes exhibit a change in voltage similar to that encountered
when a conventional battery is replaced.
Namely, the voltage thereof can be varied by crossing an
operational limit voltage of the electric watch.
For this reason, when applying this power supply to a multifunction
watch, the above-noted technique for hand position storage is
extremely effective. If this technique is not provided, each time
the power supply voltage falls below the operational limit voltage,
it is necessary to perform a reference position adjustment.
However, even when the above-noted hand position storage technique
is applied, if the power supply voltage varies in the region
surrounding the operational limit voltage, it is necessary to
repeatedly perform the hand position writing and hand position
reading operations, thereby resulting not only in wasteful
consumption of electrical power, but also in the possibility that
the writing and reading operations will not be performed
accurately.
In addition, in the above-noted electronic watch having an
electrical generation mechanism, if the amount of charge of the
electrical power storage means which is the electrical generation
means as a power supply means, is insufficient, it was necessary to
notify the user of this condition, as a prompt to perform
charging.
As a means of solving this problem, in accordance with the
disclosure in the Japanese Unexamined Patent Publication (KOKAI)
No. 62-194484, by changing the type of movement of the second hand,
notification is made of the insufficient charge, and if the voltage
is restored after the watch has stopped, hand movement different
that the above is performed, to notify the user that the watch had
stopped, and that the displayed time has been disturbed. However,
in the above-noted technology, because the second hand continues to
be driven even when the voltage of the electrical power storage
means has decreased, valuable electrical power is consumed, this
resulting in an acceleration of the drop in the voltage of the
secondary cell.
However, if the second hand is stopped, there is a danger that the
user might be caused to misinterpret this as indicating that the
watch has totally stopped, if the second hand is merely stopped,
the value of the watch as a product will decrease.
SUMMARY OF THE INVENTION
An object of the present invention is to solves the problems
presented by the above-noted in the prior art, by establishing a
system that can be applied to a multifunction watch having a power
supply comprising an electrical generation mechanism, and by
providing an electronic watch which is capable of accurately
notifying the user of the amount of charge in the electrical power
storage means, without wastefully using electrical energy.
To achieve the above-noted object, the present invention uses
basically the following technical constitution.
Specifically, in an electronic watch having a electrical generation
means, an electrical power storage means which stores electrical
energy generated by the above-noted electrical generation means, an
oscillator circuit, a control section which operates in response to
a clock of the above-noted oscillator circuit, and a display
section which is controlled by the above-noted control section, and
which displays the time and also selectively displays a function
other than the time, a voltage detection means for detecting the
voltage of the electrical power storage means and a control section
management means for controlling the operation of the control
section in response to a detection signal of the voltage detection
means are provided, a first specific aspect of the above-noted
electronic watch being an electronic watch configured as noted
above, and further configured so that the above-noted control
section management means exhibits hysteresis at the starting point
of the operation of the control section and the ending point of the
operation of the control section, and a second aspect of the
above-noted electronic watch being an electronic watch configured
as noted above, and further configured so that the above-noted
control section management means operates the control section in
response to a detection signal of the detection means, and stops at
least one of a plurality of hands used in the time display at a
pre-established position for the purpose of indicating the current
voltage level of the above-noted electrical power storage
means.
Because an electronic watch according to the present invention uses
the technical constitution described above, in an electronic watch
which is controlled by a microcomputer, when switching from the
normal control state to the charge warning state, by providing
hysteresis at the voltage value at which the operation changes,
even in the case in which the voltage of the power supply, which is
the electrical generation means, is derived from a secondary cell
which exhibits instability, there being no excessively frequent
change in conditions so that no useless disturbance is given to a
user thereof, or even at the point at which a switch is made from
the charge warning state to the stopped state, the provision of
this hysteresis in the voltage value provides the advantage that
unnecessary hand position storage operations are not performed,
there being no excessively frequent changes in condition, the user
not being confused, and the reset cancel operation not being
performed with excessive frequency.
Additionally, because it is possible to indicate the charge
condition of the electrical generation means or the electrical
power storage means of the electronic watch by stopping a hand
thereof at a particular position, it is possible to inform the user
of the need for a charging operation without unnecessarily
consuming electrical energy.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit block diagram of a multifunction electronic
watch having an electrical generation mechanism according to the
present invention.
FIG. 2 is an outer view of a multifunction electronic watch having
an electrical generation mechanism according to the present
invention.
FIG. 3 is a circuit block diagram of an electrical generation means
of a multifunction electronic watch having an electrical generation
mechanism according to the present invention.
FIG. 4 is a drawing which shows the discharge characteristics of a
secondary cell with relation to the present invention.
FIG. 5 shows a chart showing relationship among several
state-transitions to be considered in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
An example of an electronic watch according to the present
invention will be described in detail, with reference being made to
the accompanying drawings.
FIG. 1 is a simplified block diagram which shows an example of the
configuration of an electronic watch 300 according to the present
invention. In this drawing, the electronic watch 300 comprises an
electrical generating means 26, an oscillator circuit 32, a control
section 100 which operates in response to a clock of the oscillator
circuit 32, and a display section 500 which displays the time and
also selectively displays a function other than the time, the
electronic watch 300 being provide with a voltage detection means
27 which detects the voltage of the electrical generation means 26
and a control section management means 400 which controls the
operation of the control section 100 in response to a detection
signal of the voltage detection means 27.
The oscillator circuit 32 which is used in the electronic watch 300
according to the present invention can be a quartz crystal
oscillator circuit, for example, and the electrical generation
means 26 which functions as the power supply for the present
invention includes an electric power generator means 51 and an
electrical power storage means 52/53 which stores the electrical
energy generated by the electric power generator means 51.
The electric power generator means 51 which is used in the present
invention is a power supply having characteristics such that its
output voltage varied with the passage of time and it is
particularly desirable that this be a battery with characteristics
that exhibit an increase and a decrease in output voltage with the
passage of time. Examples of this include a solar cell and a
mechanical-type electrical generation means.
The electrical power storage means 52/53 used in the present
invention can be a capacitor or the like, can also be an
appropriate secondary cell, and can further be a combination of the
both of these.
Therefore, the voltage detection means 27 of the present invention
detects the output voltage of either the electrical power storage
means 52 or 53.
The control section management means 400 of the present invention
is configured so as to control the starting point and the ending
point of operation of the above-noted control section 100, in
response to a detection signal from the above-noted voltage
detection means 27.
An example of the first aspect of an electronic watch 300 according
to the present invention will now be described, with reference made
to the related drawings.
An embodiment of present invention is described below. FIG. 1 is a
circuit block diagram which shows an embodiment of the present
invention.
In FIG. 1, the reference numeral 1 denotes an oscillator circuit,
which outputs a 32768 Hz reference signal, using a quartz crystal
(not shown in the drawing) as the oscillation source, and 2 is a
frequency divider circuit, which frequency divides the reference
signal from the oscillator circuit 1.
The reference numeral 3 denotes a waveform-shaping circuit, which
outputs step pulses for the purpose of driving an hour/minute
display means comprising an hour/minute hand 9 and a second display
means comprising a second hand 6, these to be described later, and
4 is a second-motor drive circuit, which converts a step pulse from
the waveform-shaping circuit 3 to a signal for motor driving.
The reference numeral 5 denotes a second motor, which rotates in
response to a drive signal from the second-motor drive circuit 4.
The reference numeral 6 is a second display means comprising a
second hand, which performs step movement in accordance with the
rotation of the second motor 5.
The reference numeral 7 denotes an hour/minute drive circuit, which
converts a step pulse from the waveform-shaping circuit 3 to a
signal for motor driving, 8 is a minute/hour motor which rotates in
response to a drive signal from the minute/hour motor drive circuit
7, and 9 is a minute/hour display means comprising a minute/hour
hand, which performs step movement in accordance with the rotation
of the minute/hour motor 8.
In this same FIG. 1, the reference numeral 10 denotes a second-hand
position counter, which is a base-60 counter that is linked to the
second hand 6, 11 is a chronograph motor drive circuit which
converts a 1/20-second signal from the waveform-shaping circuit 3
to a signal for driving a chronograph motor, 12 is a chronograph
motor which rotates upon receiving a signal from the chronograph
drive circuit, 13 is a chronograph display means comprising a
chronograph hand which moves in steps in accordance with the
chronograph motor 13 rotation, 14 is a chronograph position counter
which is linked to the chronograph hand 13, 15 is a chronograph
counter which counts the chronograph time.
In this embodiment, the display means 500 comprises the hour/minute
display means 9, the second display means 6, and the chronograph
display means 13.
In the same FIG. 1, reference numeral 16 denotes a second counter,
which counts the current time, and 17 is a 21 counter, which is
fixed at the value 21. Similarly, 18 is a 24 counter, and 19 is an
18 counter.
The reference numeral 20 denotes a selector means, which when a
signal is input to any of the control terminals C1, C2, or C3,
performs to output a signal output from any one of the input
terminals I1, I2, I3 and I4, in response to the one of the control
terminals C1, C2, or C3 to which the input signal is input. For
example, when an input signal was input to the control terminals
C1, the output signal is output form the input terminal I1.
Furthermore, if a plurality of control signals are input
simultaneously, the one having the lowest number has priority. The
reference numeral 21 denotes a coincidence detection circuit, which
when it detects coincidence between the contents output from the
selector means 20 and the contents of the second-hand position
counter 10 outputs a detection signal to the waveform-shaping
circuit 3, and 22 is a counter control means, which writes the
counter information of the second-hand position counter 10 and
chronograph position counter into non-volatile memory, to be
described later, and read this information from the non-volatile
memory.
At the point at which writing is completed, a writing completed
signal is output, and at the point at which readout is completed, a
readout completed signal is output. The reference numeral 23
denotes a non-volatile memory, into which are stored counter
information of the second-hand position counter 10 and the
chronograph hand position counter 14, under control of the counter
control means 22.
That is, in the case in which C1 and C2 are input simultaneously,
the signal I1, which corresponds to C1, will be output with higher
priority, and if C2 and C3 are input simultaneously, the signal I2,
which corresponds to C2, will be output with higher priority. If
none of the signals C1 through C3 are input, I4 is output.
The reference numeral 24 is an input means, which comprises an
external operating switch, 25 is a hand setting warning signal
output means, which outputs a hand setting warning signal starting
immediately after a reset signal from a microcomputer reset means
33 is canceled, the output of the hand setting warning signal being
stopped by means of an operating signal of the switch means 24. The
reference 26 numeral denotes an electrical generation means formed
by, for an example, a solar cell and a storage cell, and 27 is a
voltage detection means, which outputs a first detection signal S1
if the voltage from the electrical generation means 26 is 1.27 V or
lower, a second detection signal S2 if the voltage from the
electrical generation means 26 is 1.20 V or lower, and a third
detection signal S3 if the voltage of from the electrical
generation means is 1.15 V or lower.
Reference numeral 28 denotes a charge warning signal output means,
which outputs a charge warning signal JS when it receives the
signal S1 from the voltage detection means 27, the output of the
signal JS being stopped 30 second after the signal S1 is canceled,
and 29 is a stoppage warning signal output means, which outputs a
stoppage warning signal TS when it receives the signal S3 from the
voltage detection means 27, the output of the stoppage warning
signal TS being stopped when the signal S2 is canceled.
The above-noted hand setting warning signal output means 25, charge
warning signal output means 28, and stoppage warning signal output
means 29 are configuration so as to output their respective signals
immediately after operation starts.
The reference numeral 30 denotes a mode control means, which
controls the switching of the mode of the electronic watch upon
receiving a signal from the input means 24, and 31 is a OR gate
circuit which performs control so that the mode control means 30
does not operate if any one of the hand setting warning signal,
charge warning signal, and stoppage warning signal is output.
Elements such as the above-noted selector means 20, counter control
means 22, mode control means are formed as part the microcomputer
100.
In the present invention, the control section management means 400
is formed by the stoppage warning signal output means 29.
The reference numeral 32 denote an oscillation detection circuit,
which outputs an oscillation detection signal when the oscillator
circuit 1 is oscillating, and 33 is a microcomputer reset means,
which in the condition in which the stoppage warning signal is
being output, if it receives either the oscillation detection
signal output by the oscillation detection circuit 32 or the
writing completed signal from the counter control means 22, outputs
a microcomputer reset signal.
Within the above-described configuration, the watch circuit 200 is
formed by, for example, the oscillator circuit 100 and the
microcomputer 100.
Next, the operation of an embodiment of the present invention will
be described, with reference being made to FIG. 1 and FIG. 2 is an
outer view of a multifunction electronic watch having an electrical
generation mechanism according to the present invention.
In FIG. 2, the reference numeral 50d denotes a condition indicating
section which indicates the condition of the electronic watch 300,
this condition indicating section 50d comprising an warning mark
50a which indicates the charge warning state, a stop mark 50b which
indicates the stopped state, and the hand setting mark 50c which
indicates the hand setting state.
The reference numeral 51f denotes a mode indicating section, the
mode mark of which that is currently being pointed to by the mode
hand 51e being the current mode. In FIG. 2, "TIME" is being pointed
to, indicating that the current mode is the normal time mode.
In an electronic watch 300 according to the present invention,
while it is necessary to at first cause the second hand 6 and the
chronograph 13 to coincide with a reference position, this will not
be described, since it is done by mean of known technology.
The case in which the voltage decreases is described below.
The electronic watch 300 operates as a normal multifunction watch
at a electrical generation means 26 voltage down to 1.27 V. When
the voltage of the electrical generation means 26 reaches 1.27 V,
the voltage detection means 27 outputs the first detection signal
S1, causing the charge warning signal output means 28 to output the
charge warning signal JS.
As a result, the selector means 20 switches the output from the
second counter to the 18 counter 19 contents. This results in the
second hand 6 stopping at the "warning" mark at the 18-second
position, thereby indicating the charge warning state. This is to
inform the user that the amount of electrical energy in the
electrical generation means 26 is insufficient, thereby prompting
the user to perform charging.
Additionally, because the charge warning signal JS is output to the
mode control circuit 30 via the OR gate circuit 31, the mode
control circuit 30 controls the waveform-shaping circuit 3 so as to
forcibly hold the electronic watch 300 in the time mode.
If the voltage of the electrical generation means 26 decreases
further to 1.20 V, the voltage detection means 27 outputs the
second detection signal S2.
However, even if it receives this second detection signal S2, the
stoppage warning signal output means 29 does not operate. If the
voltage of the electrical generation means 26 further decreases to
1.15 V, the voltage detection means 27 outputs the third detection
signal S3. The stoppage warning signal output means 29, upon
receiving this third detection signal S3, outputs the stoppage
warning signal TS. As a result, the selector means 20 switches the
output from the 18 counter 19 to the 21 counter 17.
The result of this is that the position of the second hand 6 moves
so that it stops at the "STOP" mark 50b in FIG. 2, and the watch
goes into the stoppage warning state.
This is the state in which the user is notified that the electronic
watch 300 is in the stopped state. Additionally, because by means
of this stoppage warning signal TS the hour/minute hand control
means 50 is not longer able to operate, the hour/minute hand 9
stops.
Next, when the stoppage warning signal TS is received and the
second-hand position counter 10 count value reaches 21, the counter
control circuit 22 writes the contents of the second-hand position
counter 10 and the chronograph hand position counter 14 into the
non-volatile memory 23.
When the writing of these contents is completed, a writing complete
signal is output to the microcomputer reset means 33. The
microcomputer reset means 33 receives this writing complete signal
and outputs a reset signal. This places the microcomputer in the
reset condition.
If the voltage stops, the oscillation of the oscillator circuit 1
also stops, so that the watch circuit 200, which includes the
microcomputer 100, completely stops.
Turning now to a description of the case in which the voltage of
the electrical generation means 26 increases, when the voltage of
the electrical generation means 26 is 0 V, all constitutional
elements shown in FIG. 1 stop. Thereafter, if, for example,
incident light is received, so that the voltage of the electrical
generation means 26 exceeds some value (normally approximately 0.75
V), the oscillator circuit 1 begins to oscillate. When this occurs,
the oscillation detection circuit 32 outputs the oscillation
detection signal.
This signal is received at the microcomputer reset means 33, which
thereupon outputs a microcomputer reset signal. This places the
microcomputer in the reset condition. Elements other than the
microcomputer 100, such as the stop-page warning signal output
means 29 are reset and initialized by means of a power-on reset
circuit (not shown in the drawing). The voltage detection means 27
also begins to operate. Because the voltage value of the electrical
generation means 26 is lower than 1.15 V, all first detection
signal S1, second detection signal S2, and third detection signal
S3 are all output.
If the voltage of the electrical generation means 26 further
increases so that it exceeds 1.15 V, the voltage detection means 27
cancels the third detection signal S3 that is being output to the
stoppage warning signal output means 29.
However, the stoppage warning signal output means 29 continues to
output the stoppage warning signal TS. For this reason, the
hour/minute hand control means 50 does not pass the pulse from the
waveform-shaping circuit 3, so that the hour/minute hand 9 remains
in the stopped condition. Because the microcomputer also remains in
the reset condition, the second hand 6 remains stopped at the STOP
mark 50b.
If the voltage of the electrical generation means 26 increases
further, so that it exceeds 1.2 V, the voltage detection means 27
cancels the second detection signal S2, at which point the stoppage
warning signal output means 29 cancels the stoppage warning signal
TS.
When the stoppage warning signal is canceled, the microcomputer
control means 33 is controlled so that the reset condition of the
microcomputer 100 is canceled. The result of this is that the
microcomputer starts to operate.
The hour/minute hand control means 50 now passes the step pulse
from the waveform-shaping circuit 3, so that the hour/minute hand 9
starts to operate. Next, the counter control means 22 starts to
operate by reading out the contents of the second-hand position
counter 10 and the chronograph hand position counter 14 from the
non-volatile memory 23, these contents being transferred to the
respective counters.
In addition, the counter control means 22 outputs a readout
completed signal to the coincidence detection circuit 21, for the
purpose of ending the readout operation. Because the microcomputer
100 has already been reset, the hand setting warning signal output
means 25 and the charge warning signal output means 28 are at this
point outputting the signals HS and JS, respectively.
Therefore, at the selector means 20, the hand setting warning
signal HS input at the C2 terminal has priority and the contents of
the 24 counter 18 are output. The coincidence detection circuit 21
controls the waveform-shaping circuit 3 until the contents of the
24 counter 18 and the contents of the second-hand position counter
10 coincide.
Therefore, the second hand 6 is stopped at the 24-second position,
which is the "HAND SETTING" mark 50c. That is, the electronic watch
is in the hand-setting state.
This is a mode which the user is warned that the watch has
completed stopped, and that the minute and hour hands indicate a
time that is different than the correct time.
If at this point the user operates the switch means 24 to set the
minute/hour hand 9 to the correct time, the hand setting warning
signal output means 25 inputs an operating signal from the switch
means 24 and cancels the output of the hand setting alarm signal
HS.
The result is that the selector means 20 outputs the contents of
the 18 counter 19, this further resulting in the second hand 6
stopping at the 18-second position, which is the "warning" mark
50a. At this point, during the period in which the OR gate circuit
31 is outputting either the hand setting alarm signal HS or the
charge warning signal JS, the mode control means 30 is controlled,
so that the electronic watch 300 is held in the time mode.
If the voltage of the electrical generation means 26 increases
further so that it exceeds 1.27 V, the voltage detection means 27
cancels the first detection signal S1. However, even if the first
detection signal S1 is canceled, the charge warning signal output
means 28 continues to output the charge warning signal JS until
that condition is maintained continuously for 30 minutes.
Then, if the cancellation of the first detection signal S1 is
detected continuously for 30 minutes, the charge warning signal JS
is canceled. When this occurs, the selector means 20 outputs the
second counter 16, resulting in the second-hand position counter 10
coinciding with the second counter 16. This causes the second hand
6 to indicate the second of the current time, and to start to step
in one-second intervals.
The mode control means 30 also goes into the operating condition,
so that by operating the switch means 24 it is possible to change
the electronic watch 300 to a different mode, such as the
chronograph mode.
The actual transition of the mode is performed by causing the
second-hand position counter 10 to coincide with the chronograph
counter (not shown in the drawing), but since this is not directly
related to the present invention, this will not be described in
further detail.
If the voltage of the electrical generation means 26 further
increases so that it becomes 2.6 V, a limiter circuit (not shown in
the drawing) operates to control the voltage so that it does not
exceed 2.6 V. This action enables operation as a normal
multifunction electronic watch when the voltage of the electrical
generation means 26 is in the range 1.27 V to 2.6 V.
The state transitions in the electronic watch 300 according to the
present invention will be described in further detail, with
reference being made to FIG. 2 and FIG. 5.
In FIG. 5, the reference numeral 501 denotes the normal state, 502
is the charge warning state, 503 is the stoppage warning state, and
504 is the hand setting warning state. In this drawing, the lines
L1 through L4 represent the voltage condition of the electrical
generation means 26, L1 being the line when the voltage of 1.27 V
is continuously detected for 30 minutes, L2 being the 1.27-V line,
L3 being the 1.20-V line, and L4 being the 1.15-V line.
The various state transitions are described below.
(1) Transition from the normal state 501 to the charge warning
state 502
In the normal state 501, it is possible to use not only the current
time display function of the electronic watch 300, but also such
other functions as the chronograph function thereof. If in this
condition the voltage of the electrical generation means 26
decreases so that it reaches 1.27 V, the electronic watch goes into
the charge warning state. In this state, the mode of the electronic
watch 300 is fixed as the current time display mode, and only the
minute/hour hand 9 is driven. The second hand 6 stops at the
"warning" mark 50a which is shown in FIG. 2. This state informs so
as to prompt the user to perform charging.
(2) Transition from the charge warning state 502 to the normal
state 501
In the charge warning state 502, if the user performs charging of
the electrical generation means 26 (application of light when the
electric generation mechanism is optical, or movement of the
electronic watch 300 if the electrical generation mechanism is
mechanical), so that the voltage thereof is 1.27 for 30 minutes,
the electronic watch 300 goes into the normal state 501.
(3) Transition from the charge warning state to the stop-page
warning state 503
If in the charge warning state the voltage of the electrical
generation means 26 further decreases so that it reaches 1.15 V,
the electronic watch 300 goes into the stoppage warning state 503.
In this state, the second hand 6 is stopped at the position of the
"STOP" mark which is shown in FIG. 2, and the microcomputer is in
the reset condition, so that the minute/hour hand 9 is stopped.
(4) Transition from the stoppage warning state 503 to the hand
setting warning state 504
In the stoppage warning state 503, if the user performs charging of
the electrical generation means 26 so that the voltage thereof
exceeds 1.20 V, the microcomputer 100 begins to operate, and the
electronic watch 300 transitions into the hand setting warning
state 504. In this state, the second hand 6 is stopped at the HAND
SETTING mark which is shown in FIG. 2, to notify the user that it
is necessary to correct the time of the minute/hour hand 9, which
has been disturbed.
(5) Transition from the hand setting warning state 504 to the
stoppage warning state 503
In the hand setting warning state 504, if the voltage of the
electrical generation means 26 falls to 1.15 V, transition is made
to the stoppage warning state 503, and the second hand 6 stops at
the STOP mark 50b which is shown in FIG. 2.
(6) Transition from the hand setting warning state 504 to the
charge warning state 502
In the hand setting warning state 504, when hand setting is
performed by operating the input means 24, transition is made to
the charge warning state 502. When this occurs, the second hand 6
stops at the WARNING mark which is shown in FIG. 2, and the
minute/hour hand 9 begins to indicate the current time.
(7) Transition from the hand setting warning state 504 to the
normal state 501
In the hand setting warning state, if the user does not perform
hand setting, even the voltage of the electrical generation means
26 increase so that the value of voltage is detected as being 1.27
V for 30 minutes continuously, as long as the user does not operate
the switch means 24 to perform time correction, the hand setting
warning state 504 will be maintained. In this case, however, when
time correction is performed, transition is made to the normal
state.
As described above, whereas the transition from the normal state
501 to the charge warning state 502 is made when the voltage value
of the electrical generation means 26 becomes 1.27 V, the
transition from the charge warning state 502 to the normal state
501 is only made when the voltage value of the electrical
generation means 26 is detected as having reached 1.27 V for 30
minutes.
By providing this temporal hysteresis between these two state
transitions, frequent state transitions are prevented in the case
in which the voltage of the electrical generation means 26 varies
in the region of 1.27 V.
Additionally, whereas the transition from the charge warning state
502 to the stoppage warning state 503 is made when the voltage
value of the electrical generation means 26 becomes 1.15 V, the
transition from the stoppage warning state 503 (via the hand
setting warning state 504) is made when the voltage value of the
electrical generation means 26 becomes 1.2 V, thereby providing
voltage hysteresis between these two states and making it possible
to eliminate state transitions and prevent unnecessary hand
position storage operations when the voltage value of the
electrical generation means 26 varies between 1.15 and 1.2 V.
Although the above is a description of the state transitions in an
electronic watch according to the present invention, the present
invention is not limited in this manner, and it is possible to
provide either temporal hysteresis and voltage hysteresis between
any state transition.
A different aspect of the present invention is an electronic watch
comprising an electrical generation means, an electrical power
storage means which storage energy generated by the above-noted
electrical generation means, an oscillator circuit, a control
section which operates in response to a clock from the above-noted
oscillator circuit, and a display section which is controlled by
the above-noted control section, and which displays the time and
also selectively displays a function other than the time display,
this electronic watch being provided with a voltage detection
means, having a first mode in which the above-noted function other
than the time display operates based on the voltage of this voltage
detection means, and a second mode in which, based on the voltage
of the voltage detection means the above-noted function other than
the time display does not operate, hysteresis being provided
between the point of transition from mode 1 to mode 2 and the point
of transition from mode 2 to mode 1.
Next, a specific configuration of the electrical generation means
26 will be described, using FIG. 3.
In this drawing, reference numeral 51 denotes an electric power
generator means, which can be, for example a solar cell, in which
case it would generate electrical energy in response to received
light, 52 is a small-capacitance capacitor, which is an electrical
power storage means for the purpose of quickly operating the watch
circuit 200 which is shown in FIG. 1, and 53 is a secondary cell,
which is used in along with the small-capacitance capacitor 52 to
store electrical energy that is generated by the solar cell or
other type of electric power generator means 51.
The reference numerals 55 and 56 denote reverse-current preventing
diodes which prevent leakage of a charge which is stored in the
small-capacitance capacitor 52 and in the secondary cell 53 via the
solar cell 51, and 54 is a time-division switch, which is
configured by an NPN-type MOS transistor.
The time-division switch 54 is provided to receive a prescribed
clock from the oscillator circuit 2 and alternately charge the
small-capacitance capacitor 52 and the secondary cell 53. The
reference numeral 55' is a capacitively coupled switch, which is
configured by an NPN-type MOS transistor. The capacitively coupled
switch 55' is controlled by the above-described stoppage warning
signal, so that it switches to on when the stoppage warning signal
is canceled.
In addition to the solar cell used in the descriptions above, the
electric power generator means 51 used in the present invention can
be a mechanical electrical generating means which makes used of the
movement of the arm, for example, to generate electrical energy.
Additionally, both of the electrical power storage means 52 and 53
are not absolutely necessary, it being possible to use a capacitor
or a plurality thereof only or to use only a secondary cell
alone.
The operation of the electrical generation means 26 will be
described below, with reference being made to FIG. 3.
Assume first that there is amount of stored energy in the
small-capacitance capacitor 52 and the secondary cell 53 is zero,
and that light is not being received. In this condition, if light
strikes the solar cell 51, an electrical voltage will be generated.
Because the time division switch 54 is off at this point, the
generated voltage is stored in the small-capacitance capacitor 52.
Because the small-capacitance capacitor 52 has a small capacitance,
it is charged quickly, this being used as electrical energy to
start operation of the watch circuit.
First, the oscillator circuit 1 begins to oscillate, a clock which
is derived by frequency dividing the oscillation signal thereof
controlling the time division switch 54 so as to charge the
small-capacitance capacitor 52 and the secondary cell 53
alternately. However, because the voltage of the secondary cell 53
does not increase immediately, the watch circuit operates for a
while from the small-capacitance capacitor 52.
Next, the characteristics of the secondary cell 53 used as the
electrical power storage means 53 in this embodiment will be
described, using FIG. 4. FIG. 4 shows the discharge characteristics
of a titanium lithium ion secondary cell used in this embodiment.
Because this secondary cell is not only compact, and also because
compared to a large-capacitance capacitor that was used in the
past, the amount of storage is very large, it is suitable for use
as an electrical generation means in an electronic watch having a
electrical generation mechanism.
However, as shown in FIG. 4, when the amount of charge in this
titanium lithium ion secondary cell decreases, it exhibits a sharp
decrease in voltage in the 1.2 V region. To be able to use a
charged secondary cell for as long as possible, then, it is
desirable to stop the operation of the microcomputer in the region
of 1.15 V.
Doing this, however, requires the hand position storage operation,
which was described earlier, when the voltage of the secondary cell
crosses the 1.15 V level. If however, as is done in this
embodiment, the voltage at which the microcomputer operation is
stopped is set at 1.15 V and the voltage at which the microcomputer
operation is started is set at 1.2 V, once the microcomputer is
stopped, because the voltage of the secondary cell will be
stabilized at the point at which the microcomputer begins operating
once again, the above-described problem is prevented.
As described above, the present invention offers a particularly
large effect when used with electrical power storage means 53
having characteristics such as those of a titanium lithium ion
secondary cell is used in combination with a power supply of type
that exhibits voltage increase and voltage decrease, such as a
solar cell or a mechanical electrical generation means.
Although in the above embodiment, temporal hysteresis is provided
at the switching point between the normal state and the charge
warning state and voltage hysteresis is provided at the switching
point between the charge warning state and the stoppage warning
state, the present invention is not limited in this manner, it
being possible to achieve the object of the present invention by
applying either type of hysteresis at any point.
As described above, in the present invention because hysteresis is
provided between the switching point between the normal state and
the charge warning state, even using a secondary cell having an
unstable supply voltage, it is possible to avoid excessively
frequent changes in state, and to avoid confusion on the part of
the user. By also providing hysteresis at the switching point
between the charge warning state and the stoppage warning state,
the frequent resetting and canceling of resetting of the
microcomputer are prevented, thereby preventing unnecessary hand
position storage operations.
Describing an example of the second aspect of an electronic watch
300 according to the present invention with reference to the above
example, as noted in the above example, an electronic watch 300
according to the present invention indicates the current voltage
level of the electrical generation means 26 by means of at least
one of the plurality of hands used in the time display, such as the
minute/hour hand, for example, the second hand 6.
In addition, in the above-noted second aspect of the electronic
watch 300 according to the present invention, it is desirable that
the control section management section 400 be configured so as to
operate the control section 100 in response to a detection signal
from the voltage detection means 27, so that at least one hand,
such as the second hand 6, of the plurality of hands used for the
time display, is caused to stop at a pre-established position for
the purpose of displaying the current voltage level of the
electrical generation means 26.
That is, in an electronic watch 300 of the second aspect of the
present invention, in addition to informing the user as to what
type of condition the voltage of the electrical generation means 26
is currently in, the type and relationship of information for the
purpose of causing execution of the necessary operation being
priorly set, so that in response to the condition the second hand
is caused to stop at a pre-established position, making it easy for
the user to understand the current condition of the electrical
generation means 26 used in the electronic watch 300.
More specifically, a plurality of positions which indicate the
current voltage level of the electrical generation means 26 are
provide, such as shown as 50a, 50b, and 50c in FIG. 2, and if the
above-noted voltage detection means 27 detects a priorly
established first voltage value, or example a level of 1.27 V or
lower, for the output voltage of the electrical generation means
26, the second hand 6 is stopped at, for example, a first stopping
position 50a, if the voltage detection means 27 detects a priorly
established second voltage value, for example a level of 1.15, for
the output voltage of the electrical generation means 26, the
second hand 6 is stopped at, for example, a second stopping
position 50b.
Specifically, the above-noted first stopping position is the
position which indicates the charge warning state of the electrical
generation means, and the above-noted second stopping position is
the position which indicates the state in which the timekeeping
function of the electronic watch 300 is stopped.
In addition, in the above-noted second aspect of an electronic
watch 300 according to the present invention, it is desirable that
the above-noted control section management section 400 be
configured so as to have an additional third stopping position 50c,
to which at least one hand, such as the second hand 6, of the
plurality of hands used in the time display, is caused to point by
the control section management section 400, in response to a
detection signal of the above-noted voltage detection means 27 and
an operation of the input operation means 24, the control section
100 so as to control the above-noted hand, thereby indicating that
the currently displayed time is not the current accurate time.
In a second aspect of an electronic watch 300 according to the
present invention, by virtue of the above-described constitution,
it is possible to stop the second hand at a position which
indicates the condition of storage of the electrical generation
means or the electrical power storage means, thereby informing the
user thereof, without having to consume electrical energy
unnecessarily.
* * * * *