U.S. patent number 3,686,880 [Application Number 05/017,806] was granted by the patent office on 1972-08-29 for electronically controlled stop watch.
Invention is credited to Toshihide Samejima.
United States Patent |
3,686,880 |
Samejima |
August 29, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ELECTRONICALLY CONTROLLED STOP WATCH
Abstract
An electronically controlled stop watch in which the output
frequency of a standard frequency oscillator is divided by a
frequency divider means, the divided frequency is counted by a
counter means, the starting and stopping of this counting are
controlled by a start-stop switch means, and by supplying power to
a display means and a register means by the operation of a time
display switch means, the content of said counting is displayed in
a display device. Preferably a single indicating lamp indicates the
off-on condition of a main power switch and also whether or not the
counter is counting. The display means is preferably powered by an
output of the frequency divider to conserve power. Moreover, reset
means is preferably related to the counter control so that the
register means cannot be accidentally reset during counting.
Inventors: |
Samejima; Toshihide (Yachiyo,
JA) |
Family
ID: |
26418348 |
Appl.
No.: |
05/017,806 |
Filed: |
September 7, 1971 |
Foreign Application Priority Data
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Sep 4, 1970 [JA] |
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45/77246 |
Sep 4, 1970 [JA] |
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45/88287 |
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Current U.S.
Class: |
368/112; 968/846;
968/925 |
Current CPC
Class: |
G04F
10/04 (20130101); G04G 9/00 (20130101) |
Current International
Class: |
G04F
10/04 (20060101); G04F 10/00 (20060101); G04G
9/00 (20060101); G04f 003/06 () |
Field of
Search: |
;58/39.5,74,23R,23A
;307/225 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wilkinson; Richard B.
Assistant Examiner: Miller, Jr.; George H.
Claims
What I claim and desire to secure by Letters Patent is:
1. An electronically controlled stop watch comprising; a power
source, a standard frequency oscillator, frequency divider means
for dividing said standard frequency to provide a selected time
signal, counter means for counting said time signal to produce a
counting output thereof, register means for receiving and
registering said counting output, display means actuated by the
output signal of said register means, start-stop switch means for
starting and stopping the counting of said counter means by
controlling said frequency divider means, reset means for resetting
said frequency divider means and counter means, and time display
switch means for supplying power to said register means and display
means only when a time is to be displayed in said display means by
the counting output of said counter means.
2. An electronically controlled stop watch according to claim 1, in
which said frequency divider means include gate means, and said
start-stop switch means includes a start-stop switch controlling
the opening and closing of said gate means to control the starting
and stopping of counting of said counter means.
3. An electronically controlled stop watch according to claim 2, in
which said start-stop means further includes an action indicating
switch interlinked with said start-stop switch and action
indicating means controlled by said action indicating switch to
indicate the on or off state of said start-stop switch.
4. An electronically controlled stop watch according to claim 3, in
which said action indicating switch has two portions in one of
which it supplies continuous current from said power source to said
action indicating means and in the other of which it supplies
intermittent current from said counter means to said indicating
means.
5. An electronically controlled stop watch comprising; a power
source, a standard frequency oscillator for producing a standard
frequency, frequency divider means for dividing said standard
frequency to provide a selected time signal, counter means for
counting said time signal to provide a time counting output
thereof, register means for receiving and registering said time
counting output, display means actuated by the output signal of
said register means, start-stop switch means for starting and
stopping the counting of said counter means by controlling said
frequency divider means, reset switch means for resetting said
frequency divider means and counter means, and time display switch
means including a time duration indication switch for supplying
power to said register means and to said display means only when a
time is displayed in said display means by the time counting output
of said counter means.
6. An electronically controlled stop watch according to claim 5, in
which said register means includes gate means, and said time
display switch means further includes a lap power switch for
supplying power to said register means and display means, and a lap
display switch controlling the opening and closing of the gate
means of said register means.
7. An electronically controlled stop watch according to claim 6 in
which said lap power switch and said lap display switch are
interlinked with each other.
8. An electronically controlled stop watch comprising; a power
source, a standard frequency oscillator for producing a standard
frequency, frequency divider means for dividing said standard
frequency to provide a selected time signal, counter means for
counting said time signal to provide a counting output thereof,
register means for receiving and registering said time counting
output, display means actuated by the output signal of said
register means, start-stop switch means for starting and stopping
the counting of said counter means by controlling said frequency
divider means, reset switch means including a reset switch to
change over said frequency divider means and said counter means to
reset level and reset release level, and a reset power switch to
control the supply of power to said register means and display
means, and a time display switch means for supplying power to said
register means and display means only when a time is displayed in
said display means by the time counting output of said counter
means.
9. An electronically controlled stop watch according to claim 8, in
which said reset switch and said reset power switch are interlinked
with each other.
10. An electronically controlled stop watch according to claim 8,
in which said frequency divider means and said counter means have
reset terminals connected by a reset line to said reset switch
means and in which said reset line is interconnected with said
start-stop switch means to prevent resetting during said
counting.
11. An electronically controlled stop watch comprising; a power
supply, a standard frequency oscillator for producing a standard
frequency, frequency divider means for dividing said standard
frequency to provide a selected time signal, counter means for
counting said time signal to produce a time counting output
thereof, register means for receiving and registering said time
counting output, display means actuated by an output signal of said
register means, start-stop switch means controlling said frequency
divider means to control the starting and stopping of counting by
said counter means, reset means for resetting said frequency
divider means and counter means, and time display means for
supplying high frequency power from said frequency divider to said
register means and display means only when a time is displayed in
said display means by the time counting output of said counter
means.
Description
This invention relates to an electronically controlled stop watch
and more particularly to an electronically controlled stop watch in
which time signals are produced by dividing and counting a standard
frequency and the starting and stopping of this counting is
suitably controlled.
Most of the hitherto-used stop watches have been purely mechanical,
but since stop watches are used more severely than wrist watches
and other watches, not only is the accuracy lowered in long use due
to friction, abrasion etc. of the mechanical parts, but also other
faults are liable to occur. On the other hand, some electrically
controlled stop watches have been introduced, but because of the
complexity of their control circuits, several defects are apt to
appear and moreover, the power consumption is rather large. In
addition, since an indicator showing the on state of a power switch
and an indicator showing whether the counter is counting or not,
are individually provided, the power consumption becomes larger. In
a small sized stop watch that houses a battery, this large power
consumption is a disadvantage. Furthermore, the reset action of the
counter is performed by use of an extremely complex control circuit
having a large power consumption. Also even when the time display
is not operated, power is supplied to the indicating part,
resulting in consuming much electric power.
The present invention overcomes the above-mentioned difficulties
and provides a newly improved electronically controlled stop watch.
A characteristic of the present invention is to provide an
electronically controlled stop watch comprising a standard
frequency oscillator, a frequency divider means that divides the
output frequency of said standard frequency oscillator, a counter
means that produces time output signal by counting the divided
frequency output signal, a register means that receives the time
output signal of the counter means, a display means that provides a
time display of the time output signal of the register means, a
start-stop means that controls the starting and stopping of
counting of the counter means, a reset means that resets the
frequency divider means and counter means, and a time display
switch means that supplies power to said register means and display
means only when the content of the counting is to be displayed by
said display means. Since, by providing the above-mentioned
construction and operation, power is supplied to the display means
only when the time display is made, the power consumption is
reduced. This is convenient especially in a small-sized stop
watch.
It is an object of this invention to provide an electronically
controlled and stabilized stop watch of low power consumption and
high accuracy that is convenient for a small-sized stop watch, by
supplying power to the register means and display means only when
the time display is made.
It is another object of this invention to provide a capability of
confirming the operational state of a stop watch by changing the
indicating condition of an action indicating means according to the
stop state and start state of the start-stop switch means.
It is a further object of this invention to assure a time
measurement from the "O" state of counting, by confirming whether
the reset operation has occurred or not from the indication of the
display means given by supplying power to the display means when
the reset operation is actuated.
It is also an object of this invention to assure a stable time
measurement by preventing a misoperation during measurement in such
a way that the reset can be actuated only when the start-stop means
is in the stop state.
It is a further object of this invention to provide an
electronically controlled stop watch, in which a high-frequency
output is taken out to open and close the power supplying gate of a
display means, whereby the power consumption is reduced by
supplying power to the display means intermittently.
The exact nature of the present invention as well as other objects
and advantages thereof, will become more apparent from
consideration of the following detailed description and the
accompanying drawing in which:
The single FIGURE is an overall block diagram of an electronically
controlled stop watch in accordance with this invention.
In this embodiment, a crystal oscillator that produces a standard
frequency is used as a standard frequency oscillator 1. A frequency
divider means 2 consists of a plurality of flip flop circuits which
divide the output frequency of the standard frequency oscillator 1
to provide a desired frequency. As the stop watch of this
embodiment is to measure 1/100 sec. as a limit, a divided frequency
output of 100 Hz is produced. A counter means 3 consists of
counters 4, 5, ....., 10. Counters 4, 5, 6 and 8 count in units of
1/100 sec., 1/10 sec., 1 second and 1 minute respectively,
producing a binary-coded decimal output. Counters 7 and 9 count in
units of 10 seconds and 10 minutes respectively, producing a
binary-coded hexa decimal output, and the counter 10 counts in
units of 1 hour and 10 hours, producing a binary-coded duo-decimal
output. A register means 11 consists of registers 12, 13, .....,
18, which receive the outputs of the counters 4, 5, ....., 10
respectively. When input gates of the registers are open, the
stored contents of said registers are changed each time when the
counting is changed. When the input gates of the registers 12, 13,
..... 18, are closed, they store the contents of counting supplied
before closing.
A display actuating means 19 consists of display actuating devices
20, 21 . . . . . 26 which supply respective output signals from the
registers 12, 13 . . . . . 18 to respective display elements of a
display device 27 after code converstion and amplification. The
display element for each unit of time of the display device 27
comprises a display pattern composed, for example, of a light
emission diode, a display tube or a liquid crystal. Thus, the
above-mentioned display actuating means 19 and display device 27
compose a display means 28.
A start-stop switch means 29 consists of a start-stop switch 30 and
an action indicating switch 31 which are mutually interlinked. The
start-stop switch 30 consists of a start-stop contact piece 32, a
stop contact point 33 and a start contact point 34. The action
indicating switch 31 consists of a contact piece 35 and contact
points 36, 37. The stop contact point 33 is connected to an input
of a gate in the frequency divider means 2. The start-stop switch
30 is connected in such a way that the gate is closed when the
contact piece 32 is connected with the stop contact point 33, and
the gate of the frequency divider means 2 is opened when the
start-stop contact piece 32 is connected with the start contact
point 34. In other words, the start-stop switch 30 controls the
opening and closing action of the input gate of the frequency
divider means 2 by supplying two different signal levels. The start
contact point 34 is connected to the reset terminals of the
frequency divider means 2 and the counter means 3. The reset level
is set in such a way that the reset is released when said reset
terminals are brought to ground potential. The action indicating
switch 31 controls means for indicating the operational state of
the start-stop switch 30. This action indicating means 38 consists,
for example, of a lamp. The contact point 36 of the action
indicating switch 31 is at ground potential, and the contact point
37 is connected to the output terminals of the counter 6 which
produces a signal of 1 second period. One terminal of the action
indicating means 38 is connected to a power source 40 through a
power switch 39, and the other terminal thereof is connected to the
contact piece 35 of the action indicating switch 31.
A time display switch means 41 is composed of a time duration
indicating switch 42 and a lap time switch means 43. The lap time
switch means 43 controls the display device 27 to display a
particular time during the time elapsed, and consists of a lap
power switch 44 to supply power to the register means 11 and the
display means 28, and a lap display switch 45 that opens and closes
the input gates of the registers 12, 13 . . . . 18. The lap power
supply switch 44 is composed of a contact piece 46 and contact
points 47, 48, and the lap display switch 45 is composed of a
contact piece 49, a lap display contact point 50 and a lap display
stop contact point 51. The contact pieces 46, 49 are interlinked
with each other so as to operate together. The contact piece 46 is
connected to the power source 40, through the power switch 39, and
the contact point 47 is connected to the power input terminals of
the register means 11 and the display means 28. The contact point
50 is connected to the input gates of the registers 12, 13 . . .
18. The time duration indicating switch 42 is connected between the
power switch 39 and the contact point 47 and, when switched on,
gives an indication of the content of counting, i.e., the duration
of time, of the counter means 3.
A reset switch means 52 is composed of a reset switch 53 and a
reset power switch 54. The reset switch 53 is composed of a reset
contact piece 55, a reset release contact point 56 and a reset
contact point 57. The reset contact piece 55 is connected to
ground. The reset indicating power switch 54 is composed of a reset
power contact piece 58 that is interlinked with the reset contact
piece 55, a reset power contact point 59, and a reset release power
contact point 60. The reset contact point 57 is connected to the
reset terminals of the frequency divider means 2 and the counter
means 3. The frequency divider means 2 and the counter means 3 are
reset when the reset contact piece 55 is connected with the reset
contact point 57, and released when the reset contact piece 55 is
connected with the reset release contact point 56. A high-frequency
output of the frequency divider means 2 is supplied to the power
supply gates of the display actuating means 19 and the gates are
opened and closed at this frequency.
The operation of the circuit will now be explained. First, a case
of displaying an arbitrary time duration after the start of a
counting is considered. Before starting the counting, the contact
pieces 32, 35 of the start-stop means 29 are connected with the
contact points 33, 36, and the contact pieces 46, 49 of the lap
time switch means 43 are connected with the contact points 48, 51
respectively. The contact pieces 55, 58 of the reset switch means
52 are connected with the contact points 56, 60. Then, if the power
switch 39 is closed, a current flows from the power source 40 to
ground through the action indicating means 38, contact piece 35,
contact point 36 so as to light the lamp of the action indicating
means 38, thus clearly showing that power from the power source 40
has been supplied. Power from the power source 40 is further
supplied to the standard frequency oscillator 1, frequency divider
means 2, and counter means 3, but the input gate of the frequency
divider means 2 is kept closed because the stop contact 33 is held
at ground level, so that the output of the frequency divider means
2 does not produce an output. In starting the counting, in order to
confirm that the contents of counting of the counters 4, 5 . . . 10
are at "0", the contact piece 55 of the reset switch 53 is
connected with the reset contact point 57 to reset the counters 4,
5 . . . 10 to "0".
Thus, the preparation for starting the counting is completed. At
the outset of counting, when the contact piece 32 of the start-stop
switch 30 is switched to the start contact 34, the contact piece 35
of the action indicating switch 31 is also connected to the contact
point 37. Accordingly, the action indicating means 38 is connected
to the output terminal of 1 sec. signal of the counter 6 through
the contact piece 35 and the contact point 37. Therefore, the
action indicating means 38 receives signals of 1 sec. frequency to
produce alternate lighting and extinguishing as an indication of
being in the state of counting. On the other hand, when the
start-stop switch 30 is switched to the start contact 34, the
potential of contact point 33 is brought to the opening level of
the gate of the frequency divider means 2, and the gate of the
frequency divider means 2 is opened. Therefore, the frequency
divider means 2 divides the standard frequency and produces an
output signal of 100 Hz. The output signal is supplied to the
counter 4. This is counted in the counter 4 and, when a counting of
0.1 sec. is reached, a carry signal is produced from the counter 4
and supplied to the counter 5. When a counting of 1 sec. is reached
in the counter 5, a carry signal is produced from the counter 5 and
supplied to the counter 6. The counter 7 counts 10 sec. units, and
when the counting reaches 60 sec., a carry signal is produced and
supplied to the counter 8. Thus, the counting of respective time
units is performed successively with the lapse of time and the
respective contents of counting are produced at the output
terminals of the respective counters 4, 5, 6 . . . 10 and supplied
to the registers 12, 13, 14 . . . 18. However, the register means
11, display actuating means 19 and the display device 27 are not
supplied with power from the power source 40, so that all of them
are at a standstill.
In case of indicating the time elapsed, when the time duration
indicating switch 42 is switched on, power from the power source 40
is supplied to the register means 11, display actuating means 19,
and display device 27. Therefore, the counting output of the
counter means 3 is converted into a signal for display by the
display actuating means 19 through the register means 11 and, on
being amplified further, indicates the time elapsed by means of the
display device 27. For example, if the elapsed time when the time
duration indicating switch 42 is closed is 15 min. 15 sec., the
time is indicated in the display device 27.
Next, the display action of lap time will be explained. When the
lap time switch means 43 is operated, the contact piece 46 of the
lap power switch 44 is switched to the contact point 47, whereby
power from the power source 40 is supplied to the register means
11, display actuating means 19 and display device 27. On the other
hand, the contact piece 49 of the lap indicating switch 45 is
switched to the contact point 50 to close the gate of the register
means 11, and the counting output from the counter means 3 to the
register means 11 is stopped. Therefore, the time at the time when
the lap indicating switch 45 is switched on is stored in the
register means 11, the output thereof is converted into a signal
through the display actuating means 19, and the lap time is
displayed in the display device 27. In the meanwhile, counting is
being carried out in the counter means 3, which is confirmed by the
on-and-off of the action indicating means 38. When the display of
the lap time is completed, the contact pieces 46, 49 are brought
into contact with the contact points 48, 51 by the action of the
lap time switch means 43 again to interrupt the power supply to the
register means 11 and the display means 28, whereupon the time
display disappears. As it has been devised to supply power only
when the time display is made, the power consumption is extremely
low.
Next, the reset action will be explained in detail. The contact
pieces 55, 58 of the reset means 52 are switched to the contact
points 57, 59 and by reversing the potential level of the contact
point 56 to a value different from ground potential, the frequency
divider means 2 and the counter means 3 are held at the reset level
and are reset to "0". Since power from the power source 40 is
supplied to the register means 11, display actuating means 19 and
display device 27 by the connection between the contact piece 58
and the contact point 59, the "0" output of the counter means 3 is
fed to the register means 11 and a "0" indication is made by the
display device 27 through the display actuating means 19. In this
way it is confirmed that the resetting of the counter means 3 has
been performed.
It is noted that the resetting mentioned above cannot occur during
the action of counting. During this action, the contact piece 32 of
the start-stop switch 30 is connected with the start contact 34,
and the start contact 34 is at ground potential. Therefore, the
reset inputs of the frequency divider means 2 and the counter means
3 are at ground potential, so that even though the contact piece 55
of the reset switch 53 is switched on to the reset contact point
57, the reset inputs of the frequency divider means 2 and the
counter means 3 are kept at ground potential and no resetting is
effected.
To stop the counting, the contact pieces 32, 35 of the start-stop
switch means 29 are switched to the contact points 33, 36 on the
stop side by the action of the start-stop switch means 29, and the
output of the frequency divider means 2 is stopped by closing the
gate of the frequency divider means. Accordingly, the counter means
3 is in a state of storing the content of counting and, when the
start-stop switch 30 is switched again to the start contact 34, the
subsequent time will be integrated with the former content of
counting. Therefore, it is convenient to use for the purpose of
integrating additional time with the former time. On the other
hand, by being connected to ground through the contact piece 35,
the action indicating means 38 is in a lighting state.
As described in detail above, the power source supply and the
counting action state are shown by a single indicating means and,
by making the reset switch means relate to the start-stop switch
means, the reset action is actuated only when the counting is
stopped. By supplying power to the register means and the display
means, the "0" indication is made to appear on the display device,
and further in the case of indicating the elapsed time and the lap
time, power is supplied to the register means and the display means
by the action of the time display switch means. As a result, it is
possible to confirm the conditions of supply of power and action of
counting by one action indicating means. Moreover, since the reset
action is performed in relation to the start-stop switch and the
reset switch, it is possible to make the construction simple and
the operation reliable. Even if the reset switch is operated by
mistake during the action of counting, no effect at all will be
caused. Further, since power is supplied to the register means and
the display means only in the case of time indication, the power
consumption is very low. This is particularly convenient for a
small-sized stop watch in which a battery is housed. Furthermore,
since the required action is directly realized by means of
switches, there is provided a stop watch of simple construction and
reliable performance.
In the above-mentioned embodiment, the number of counters 4, 5 . .
. 10, and the dividing ratio of frequency divider means 2 are
determined according to the time to be measured. For example, in
the case of a stop watch that counts only up to 60 min., the
counter 10, register 18 and display actuating device 26 are not
needed. Accordingly, the numbers of counters and registers are
increased or decreased as required. In the case of the present
embodiment, the action indicating means 38 is supplied with
intermittent current from the output of an appropriate stage of the
frequency divider means 2 or the counter means 3. In case the
action indicating means 38 is not needed, the start-stop means 29
may consist of only the start-stop switch 30. Also, since the
function as a stop watch may be accomplished by providing a display
of an elapsed time, the lap time switch means 43 is not needed. In
this embodiment, the contact piece 46 and the contact piece 49 of
the lap time switch means 43 are interlinked, but the contact piece
46 and the contact piece 49 may be separated from each other to
constitute independent switches individually. In this case the
display of lap time may be made in such a way that, by actuating
the switch for supplying power, the power is supplied to the
register means 11 and the display means 28, then by actuating the
switch for lap time, the lap time is obtained. However, the
construction of interlinking the power supply switch with the lap
time switch affords low power consumption.
If the reset switch means 52 is merely required to carry out the
reset action of the frequency divider means 2 and the counter means
3 only, but not to make a display confirming that the reset has
been done, the reset switch means 52 will comprise the reset switch
53 only.
Further, in the present embodiment the power supply gate of the
display means 28 is opened and closed by the high frequency output
from the frequency divider means 2 to reduce the power consumption.
But if there is no particular necessity of reducing power
consumption, the display device 27 may be supplied with continuous
current instead of intermittent current from the output from the
frequency divider means 2.
* * * * *