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The present invention relates to a digital electronic watch and more
particularly to a digital electronic watch which displays the time in
digital form and which also displays the time remaining before the
expiration of a preset time period.
Many types of mechanical watches and electronic watches are available for
indicating the time in various forms but these watches are not equipped to
display the amount of time remaining before the elapsing of a preset time
period. There are numerous instances when a person wants to know how much
time remains before the expiration of a certain time interval, for
example, students taking timed examinations frequently wish to know how
much time remains within the examination period; businessmen oftentimes
make appointments and would like to know the time remaining before their
appointment; and housewives have many occasions where they wish to know
when a certain time period has elapsed, such as during cooking, adhering
to a schedule of activities, etc.
Unfortunately, the prior art watches do not provide any type of
remaining-time display device for visibly displaying the amount of time
remaining within a preselected time period. As a result, conventional
watches are useful only as timepieces and do not automatically inform the
wearer of the time remaining within a preselected time period.
It is therefore a primary object of the present invention to provide a
watch having a remaining-time display device for displaying the time
remaining from the instant the device is turned ON to the expiration of a
time period set into the device.
It is another object of the present invention to provide a digital
electronic watch having a time display device for displaying the time in
digital form and a remaining-time display device for displaying the time
remaining within a preselected time period.
It is a further object of the present invention to provide a digital
electronic watch having a remaining-time display device including an alarm
for providing an audible warning signal signifying the expiration of a
predetermined portion of the time period being displayed by the
remaining-time display device.
It is yet another object of the present invention to provide a digital
electronic watch having a remaining-time display device which may be
manually set to display a wide range of different time periods thereby
increasing the diversity of purposes to which the watch may be put.
It is still another object of the present invention to provide a digital
electronic watch having a time display device for displaying the time
remaining within a predetermined period and which is smart in appearance
strong in construction and reliable in operation.
The above and other objects of the present invention are carried out by a
digital electronic watch having a time display section for displaying the
time in digital form, a remaining-time display section composed of a
column of liquid crystal display panels, remaining-time display circuitry
for sequentially and progressively energizing the display panels at
preselected time intervals to sequentially turn the display panels ON or
OFF thereby providing an indication of the time remaining in the
preselected time period, a manually operable switch switchable to a series
of different positions to accordingly select a series of time periods
having different durations which are to be displayed by the remaining-time
display device, and a time unit scale juxtaposed along the column of
liquid crystal panels for displaying the time periods selected by the
switch thereby enabling a person to glance quickly at the scale and
determine from the number of liquid crystal panels which are energized the
approximate amount of time remaining in the preselected time period. A
warning device provides an audible warning signal whenever the remaining
time decrease to a certain value.
Having in mind the above and other objects that will be evident from an
understanding of this disclosure, the present invention comprises the
combination and arrangements of parts as illustrated in the presently
preferred embodiments of the invention which are hereinafter set forth in
sufficient detail to enable those persons skilled in the art to clearly
understand the function, operation, construction and advantages of it when
read in conjunction with the accompanying drawings and wherein:
FIG. 1 is a perspective and schematic view of a digital electronic watch
constructed in accordance with the present invention;
FIG. 2 is a schematic block diagram of the electronic circuits employed in
the digital electronic watch;
FIG. 3 is a block diagram of one embodiment of the electronic circuits for
energizing the remaining-time display device shown in FIG. 2;
FIG. 4 is a block diagram of another embodiment of electronic circuits for
energizing another type of remaining-time display device;
FIG. 5 is a block diagram of several of the components shown in FIG. 4;
FIG. 6 is a schematic representation of a portion of the remainingtime
display device shown in FIG. 5; and
FIG. 7 is a chart showing the various possible states of the time units
display sections disclosed in FIG. 6.
One embodiment of the digital electronic watch according to the present
invention is shown in FIG. 1 and comprises a watch band 1 connected to a
watch casing 2 in a conventional manner to form a wrist watch. The watch
casing 2 includes a time display section 3 for displaying the time in
digital form and a remaining-time display section 4 for displaying the
time remaining within a certain time period preselected by the wearer of
the watch
The time display section 3 is of conventional construction and includes an
"hour" display section 5 and a "minute" display section 6 for displaying
in digital form the time in hours and minutes and the display sections
comprise a series of liquid crystal display segments. A "second" display
section 7 comprises five liquid crystal segments disposed in a row beneath
the hour and minute display sections to display the time in seconds. A
time display device developes suitable signals for controlling the
operation of the time display section 3 and will be described in detail
hereinafter.
The remaining-time display section 4 comprises six liquid crystal display
panels or members 4a-4f each having a rectangular shape and arranged in a
column one atop the other. All of the liquid crystal panels are of
conventional construction and have certain optical properties, such as
reflectivity, which vary when the liquid crystal material is electrically
energized so as to provide a shining light output as compared to the
non-shining output when the panels are non-energized. For example, when
non-energized, the liquid crystal panels assume a transparent state and
provide no shining output whereas when energized, the panels assume a
cloudy or milky white state due to light scattering and exhibit a shining
output.
A manually-actuated time-setting switch 8 is turnably mounted on the front
face of the watch casing and the switch 8 is turnable to one of three
working positions in the embodiment shown. The switch 8 is connected to
suitable circuitry to a remaining-time display device which will be
hereinafter described and sets the desired time period or time unit whose
remaining duration is to be displayed by the remaining-time display
section 4. The setting of the switch 8 also turns ON the remaining-time
display device to initiate the running of the time period. The
remaining-time display section 4 then displays the amount of time
remaining within the time unit determined by the setting of the switch 8.
For example, when the time-setting switch 8 is moved into position 1, the
remaining-time display device is placed in a one-hour mode and all the
display panels are initially energized and turned ON and the display
panels 4f-4a are then individually and sequentially deenergized and turned
OFF at 10-minute intervals to collectively provide a visible indication of
the time remaining before the expiration of the one-hour time until set by
the switch 8. When the time-setting switch 8 is moved to position 2, the
remaining-time display device is shifted into a 2-hour mode and the
individual liquid crystal panels 4f-4a are sequentially deenergized at
20-minute intervals and in a similar manner when the time-setting switch 8
is moved to position 3, the remaining-time display device is shifted to a
4-hour mode wherein the liquid crystal panels 4f-4a are sequentially and
successively deenergized at 40-minute intervals.
A time unit display section 9 is positioned along the column of liquid
crystal panels 4a-4f for displaying a time scale of the time unit set by
the time-setting switch 8. The time unit display section 9 has three
different time scales each corresponding to one of the time units selected
by the time-setting switch 8 and each scale is calibrated in hours. The
scale depicted in FIG. 1 corresponds to the one-hour mode of the remaining
time display device corresponding to the positioning of the switch 8 in
position 1. The time unit display section 9 indicates the mode setting of
the switch 8 and also provides a time reference axis to facilitate the
reading of the remaining-time display section 4.
The one-hour time scale comprises a 0 marking adjacent the liquid crystal
panel 4a and a 1.0 hour marking adjacent the liquid crystal panel 4f
indicating that the remaining-time display device is in the 1-hour mode
thus indicating to the user that the individual liquid crystal panels
4f-4a will sequentially be turned off at 10-minute intervals starting with
the liquid crystal panel 4f and progressing successively to the panel 4a.
The scale also includes a 0.5 hour marking midway between the 0 and 1.0
hour markings signifying that only one-half hour remains before the
expiration of the one hour time unit selected by the time-setting switch
8. In a similar manner, the time unit display section 9 includes a 2-hour
time scale having 0, 1.0, 2.0 hour markings corresponding to the 2-hour
mode and a 4-hour time scale having 0, 2.0, 4.0 hour markings
corresponding to the 4-hour mode.
The circuitry of the time display device and the remaining-time display
device for effecting the various operations described above is shown in
FIGS. 2 and 3. A crystal oscillator 10 generates a series of pulses at a
high frequency which serve as a time base and delivers the pulses to a
divider 11 which divides the pulses into a one-second signal having a
frequency of one pulse per second. The 1 second signal output form the
divider 11 is fed into a counter 12 which counts the pulses and at
suitable intervals, delivers the counted pulses as a timing pulse signal
to a time display device composed of a driver circuit 13 which receives
the signal and drives a display circuit 14 which displays the time in
digital form on the time display section 3.
The timing pulse signal is also fed from the counter 12 along a line 12a to
the remaining-time display device which has a divider circuit 15 having
three output lines 15a, 15b and 15c. The divider circuit 15 divides the
timing pulse signal into three different time signals each representative
of one of the time settings selected by a time-setting switch 19 which
corresponds to the switch 8 in FIG. 1. The three time signals are fed to a
gate circuit 16 and one of them is then applied to a shift register 17 for
controlling the operation of a remaining-time display circuit 18 which
displays the time remaining on the remaining-time display section 4. Thus
the setting of the switch 19 determines which of the time signals will be
applied to the shift register 17 to control the energization periods of
the individual liquid crystal panels which constitutes the remaining-time
display section.
The gate circuit 16, shift register 17 and remaining-time display circuit
18 jointly comprise electric circuit means which receive the three time
signals and effect energization of the remaining-time display section 4 in
the proper mode as selected by the switch 19.
The details of one embodiment of a remaining-time display device are shown
in FIG. 3. A divider circuit 20 corresponding to the divider circuit 15 in
FIG. 2 receives a counted pulse signal from a counter and divides the
pulse signal into a 10-minute signal having a frequency of one pulse per
10 minutes which is applied to an output line 20a, a 20-minute signal
having a frequency of one pulse every 20 minutes which is applied to an
output line 20b, and a 40-minute signal having a frequency of one pulse
per 40 minutes which is applied to an output line 20c. Each of the minute
signals is applied to a 6-bit shift register 24 through a logic circuit
composed of NAND and NOT gates. The output line 20a is connected to a NAND
gate 21 which has an output connected to a NOT gate 21a having an output
connected to the shift register 24. In a like manner, the output line 20b
is connected through a NAND gate 22 and a NOT gate 22a to the shift
register 24 whereas the output line 20b is connected through a NAND gate
23 and a NOT gate 23a to the shift register.
The 6-bit shift register 24 has six output lines 24a-24f connected
respectively to liquid crystal panels 26a-26f of a remaining-time display
section 26. A time-setting switch 26 corresponding to the switch 8 in FIG.
1 has three working positions and an output line 25a connects the switch
25 to the NAND gate 21 when the switch is in position 1, an output line
25b connects the switch 25 to the NAND gate 22 when the switch is in
position 2, and an output line 25c connects the switch 25 to the NAND gate
23 when the switch is in the position 3. The output lines from the switch
25 are also connected to a decoder 27 and an output line 27a connects the
decoder 27 to a pair of liquid crystal elements 28 and an output line 27b
connects the decoder 27 to a pair of liquid crystal elements 29.
The liquid crystal elements 28 are positioned at one end of the
remaining-time display section 26, the liquid crystal elements 29 are
positioned at the middle of the section 26 and another liquid crystal
element 30 is positioned at the other end of the section 26. The elements
28, 29 and 30 function in a manner similar to the time unit display
section 9 in FIG. 1 and visually portray the time unit selected by the
switch 25. The element 30 always displays a 0 and the pair of elements 29
alternatively disclose 0.5, 1.0 and 2.0 denoting one-half hour, 1 hour and
2 hours respectively of the time remaining and the pair of elements 28
alternatively display the numbers 1.0 and 2.0, 4.0 indicating that 1, 2 or
4 hours is the time unit selected by the switch 25.
Assuming that the switch 25 is turned ON to the position 1, signals are
generated on the register output lines 24a-24f to energize and turn ON the
liquid crystal panels 26a-26f. Position 1 corresponds to the one-hour time
unit setting and thus the panels 26f-26a will be sequentially turned OFF
at 10 minute intervals. As soon as 10 minutes have elapsed from the
positioning of the switch to position 1, the voltage applied to the shift
register 24 through the NOT circuit 21a is no longer transmitted to the
line 24f whereupon the liquid crystal panel 26f is turned OFF. The panels
26e-26a are sequentially and progressively turned OFF in this fashion at
10 minute intervals thereby providing a visual display of the remaining
time.
When the switch 25 is turned ON to position 1, voltage is applied through a
line 25d to the decoder 27 causing suitable voltages to be generated on
the lines 27a and 27b to drive the pair of elements 28 to display the
number 1.0 and to drive the pair of elements 29 to display the number 0.5
and as aforementioned, the element 30 is always driven to display 0. The
time unit display elements 28 - 30 thus indicate that the remaining-time
display section 26 is operating in the 1-hour mode and therefore each
individual panel will be deenergized at ten minute intervals until 1 hour
has elapsed.
In the embodiment of FIG. 3, the time remaining is displayed by
progressively and sequentially turning OFF the liquid panels 26f-26a at 10
minute intervals. Of course, it is understood that the liquid crystal
panels 26f-26a may be sequentially turned ON at 10 minute intervals to
portray the elapsing time and by this arrangement the time remaining
within the preselected time unit will be displayed as a progressively
decreasing number of darkened panels rather than a progressively
decreasing number of lighted panels.
When the time-setting switch 25 is set in the position 2, the
aforementioned mode of operation is repeated except in this instance, the
time reference scales 28 - 30 display respectively 2.0, 1.0 and 0
indicating that a 2-hour time unit has been selected and the liquid
crystal panels are sequentially turned OFF by the register 24 at 20-minute
intervals. In a similar manner, when the switch 25 is set to the position
3, the scales 28 and 29 respectively display the hour markings 4.0 and 2.0
signifying that a 4-hour time unit has been selected and the individual
liquid crystal panels are turned OFF at 40-minute intervals.
The periodic energization or deenergization of the liquid crystal display
panels at predetermined time intervals provides a visual indication of the
remaining time in digital form which may be easily viewed by the wearer of
the watch. Though the display panels do not display numbers, they do
display the remaining time in discrete units and in this sense, they
display information in digital form.
Another embodiment of the digital electronic watch according to the present
invention is shown in FIGS. 4 and 5 and in this embodiment, an alarm
device is included to provide an alarm signal after the expiration of a
preselected portion of the time set by the time-setting switch. As seen in
FIG. 4, a standard oscillator 31 generates pulses at a preselected
frequency which serve as a time base and delivers the pulses to a divider
32 which divides the pulses into a 1-minute signal having a frequency of
one pulse per minute. The 1-minute signal is applied to a 10-abic counter
decoder 33 and to a gate 37 along a line 32a. The 10-abic counter decoder
33 sums up ten of the 1-minute signals and produces a 10-minute signal
having a frequency of one pulse every 10 minutes and applies this signal
to a 6-abic counter decoder 34 and to the gate 37 along a line 33a. In a
similar manner, the 6-abic counter decoder 34 counts six of the 10-minute
pulses and developes a 1-hour pulse having a frequency of one pulse per
hour and applies this signal to a 12-abic counter decoder 35 as well as to
the gate 37 along the line 34a.
Each of the counter decoder circuits 33-35 comprises an n-abic counter
combined with a decoder. The n-abic counters is obtained by connecting the
flip-flop circuits in cascade with suitable feed-back and an example of
such circuitry is found in the RCA COS/MOS Integrated Circuit Manual
published in March of 1971 in the chapter entitled "Counters and
Registers", pages 70 to 108. Each of the counter decoder circuits is also
connected to a time indicating device 36 which displays the time in
minutes and hours in digital form as known in the art.
The gate 37 receives a one-minute signal, a 10-minute signal and a 1-hour
signal and the particular signal to be gated by the gate 37 is determined
by the position of a manually turnable switch 38. The gate is connected to
another 6-abic counter decoder 39 which is connected to a remaining-time
display device 40 for displaying the time remaining in accordance with the
time unit selected by the switch 38. A time unit displaying circuit 41 is
connected to the switch 38 and to the remaining-time displaying device 40
and functions to change the time scale in the remaining-time displaying
device in accordance with the position of the switch 38.
The gate circuit 37, the switch 38 and the time unit displaying circuit 41
are shown in more detail in FIG. 5. An AND gate 42 receives the one-minute
signal, an AND gate 43 receives the 10-minute signal, and an AND gate 44
receives the 1-hour signal, it being understood that these signals
originate from the divider 32. The switch 38 has four setting positions
comprising a position 0 wherein the movable switch contact is connected to
a 6-bit shift register 46 and a time unit displaying circuit 47, a
position 1 wherein the movable switch contact is connected to the AND gate
circuit 42 and the time unit displaying circuit 47, a position 2 wherein
the movable switch contact is connected to the AND gate circuit 43 and the
time unit displaying circuit 47, and a position 3 wherein the movable
switch contact is connected to the AND circuit 44 and the time unit
displaying circuit 47.
In order to reset the remaining-time display device, the switch 38 is moved
to the position 0 and a signal having a predetermined voltage is applied
through the movable switch contact to the 6-bit register 46 to reset the
register 46 and therefore the remaining-time display device. When the
switch 38 is set to position 1, a signal is applied to one of the two
inputs of the AND gate 42 and therefore the 1-minute pulse signal applied
to the other input passes through the open gate and through an OR circuit
45 to the shift register 46. In a like manner, when the switch is set to
the position 2 or 3, the AND gate 43 or 44 is respectively energized and
accordingly passes therethrough the 10-minute signal or the 1-hour signal.
A remaining-time display section 48 includes six liquid crystal segments
48a-48f and each of these segments or panels is connected to an output of
the shift register 46. An alarm device 49, such as a bell or buzzer, is
connected to the end output of the shift register 46 by a line 46a and the
alarm device sounds an audible alarm when the time unit selected by the
switch 38 has expired. It is understood that the alarm device may be
connected to other outputs of the register 46 to provide an appropriate
alarm signal at times other than at the end of the time unit and for
example, the alarm could sound at the midway point of the time unit or at
any other desired time.
The time unit display device 50 is connected to the time unit displaying
circuit 47 and provides a visible indication of the particular time unit
selected by the switch 38. The time unit display device 50 includes a
display section 51 located adjacent the liquid crystal panel 48a and this
display section always displays 0, a display section 52 adjacent the
liquid crystal panel 48f for displaying the particular time unit selected
by the switch 38, and a display section 53 positioned at the upper right
side of the display section 53 for displaying either a minute or hour
symbol.
FIG. 6 is a schematic representation of an embodiment of the display
sections 51, 52 and 53. Each display section comprises a support member
having thereon a display element such as a liquid crystal element which
becomes milkly white and placed in its shining state when suitably
energized with electrical energy. The display element of the display
section 51 is in the form of a 0 since this is the only symbol displayed
by the display section 51. The display section 52 includes three distinct
liquid crystal elements comprising an E-shaped element and upper and lower
vertical elements arranged as shown and the three elements may be
selectively energized to from either the number 1 or the number 6. The
display section 53 includes two liquid crystal elements comprising a
C-shaped element and an I-shaped element which may be selectively
energized to form either a".degree." or a "'" denoting either an hour
symbol or a minute symbol. The display sections have not been shown to
scale in FIG. 6 but have been shown in enlarged form to facilitate their
understanding.
A common lead line 54 is connected to a voltage source at one end and to
individual ones of the display elements in each of the display sections as
shown in FIG. 6. The particular display elements connected to the line 54
are always energized during use of the remaining-time display device
whereas the remaining display elements in the display sections 52 and 53
are selectively energized in dependence upon the position of the
time-setting switch 38. When the switch 38 is in position 1, voltage is
applied through an OR gate 55 to the E-shaped display element of the
display section 52 and thus this element is energized along with the
element energized by the line 54 to form the number 6. At the same time,
the display section 53 has only the I-shaped element energized denoting
the minute symbol '.
When the switch 38 is in position 2, the E-shaped display element of the
display section 52 is not energized and instead, the upper vertical
element is energized and this forms along with the lower vertical element
energized by the line 54, the number 1. At the same time, voltage is
applied through an OR gate 56 to the C-shaped display element of the
display section 53 which coacts with the vertical I-shaped display element
to form the symbol .degree. denoting hours. When the switch 38 is in
position 3, the E-shaped display element of the display section 52 is
again energized and coacts with the lower vertical element to form the
number 6 while the C-shaped display element of the display section 53 is
energized coincidently with the I-shaped display element to form the
symbol .degree. denoting hours. FIG. 7 is a chart showing the numbers and
symbols present on the display sections 52 and 53 for the three positions
of the time-setting switch 38. Other display elements aside from liquid
crystals may be employed in practicing the present invention, such as
light-emitting diodes.
The invention has been described in conjunction with preferred embodiments
and it is to be understood that obvious modifications and changes may be
made without departing from the spirit and scope of the invention as
defined in the appended claims.
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