U.S. patent number 3,803,834 [Application Number 05/329,973] was granted by the patent office on 1974-04-16 for wristwatch calculator.
This patent grant is currently assigned to Time Computer, Inc.. Invention is credited to Robert O. Reese.
United States Patent |
3,803,834 |
Reese |
April 16, 1974 |
WRISTWATCH CALCULATOR
Abstract
Disclosed is a combination wristwatch and wrist calculator. The
wristwatch comprises an eight digit electro-optical display
indicating time and calendar information when in the time display
mode and indicating the result of a computation when in the
calculate mode. A manually operated mode switch controls the
display and calculations are entered by way of a miniature keyboard
on the watch face.
Inventors: |
Reese; Robert O. (Lancaster,
PA) |
Assignee: |
Time Computer, Inc. (Lancaster,
PA)
|
Family
ID: |
23287806 |
Appl.
No.: |
05/329,973 |
Filed: |
February 6, 1973 |
Current U.S.
Class: |
708/111; 200/5A;
D10/31; 368/87; 368/239; 368/159; 434/202; 968/937; 200/5R |
Current CPC
Class: |
G04G
9/007 (20130101); G06F 15/0208 (20130101); G06F
3/0202 (20130101); H01H 13/84 (20130101) |
Current International
Class: |
H01H
13/84 (20060101); H01H 13/70 (20060101); G06F
3/02 (20060101); G04G 9/00 (20060101); G06F
15/02 (20060101); G04b 047/06 (); G04b
019/30 () |
Field of
Search: |
;58/4,23R,23A,5R,127,152R ;235/152 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wilkinson; Richard B.
Assistant Examiner: Jackmon; Edith C. S.
Attorney, Agent or Firm: LeBlanc & Shur
Claims
What is claimed and desired to be secured by United States Letters
Patent is:
1. A combination wristwatch and wrist calculator comprising a
wristwatch case, an electro-optical digital display on said case, a
timing circuit in said case, means for coupling said timing circuit
to said display, a calculator keyboard on said case, an electronic
calculator circuit in said case coupled to said keyboard, and means
for coupling said calculator circuit to said display.
2. A device according to claim 1 wherein said display comprises a
plurality of light emitting diodes.
3. A device according to claim 1 wherein said electro-optical
display comprises four display stations for displaying the hours
and minutes of time.
4. A device according to claim 3 wherein said display comprises
additional display stations for displaying calendar
information.
5. A device according to claim 4 wherein said additional stations
comprise four stations for displaying day and month in numerical
form.
6. A combination wristwatch and wrist calculator comprising an
electro-optical digital display, a power source coupled to said
display, an electronic timing circuit including a reference
frequency electrical signal source, a decoder coupling said timing
circuit to said electro-optical digital display, a calculator
keyboard, an electronic calculator coupled to said keyboard, and a
manually operated switch for coupling said electronic calculator to
said decoder, said decoder coupling the output of said calculator
to said display when said switch is operated.
7. A device according to claim 6 wherein said reference frequency
electrical signal source comprises a crystal oscillator.
8. A device according to claim 6 wherein said power source
comprises a battery.
9. A device according to claim 8 including a voltage up-converter
coupling said battery to said electro-optical display.
10. A device according to claim 6 wherein said switch is actuated
by a mode button on said device.
11. A device according to claim 6 wherein said switch also couples
said power source to said electronic calculator whereby said
calculator is only energized upon operation of said switch.
12. A combination wristwatch and wrist calculator comprising a
wristwatch having a watch face, an electro-optical digital display
on said watch face, a power source coupled to said display, an
electronic timing circuit including a crystal oscillator and
divider normally coupled to said display, a keyboard mounted on
said watch face adjacent said display, an electronic calculator
coupled to said keyboard, and a manually operated mode switch
coupled to said timing circuit and to said calculator for
uncoupling said display from the output of said timing circuit and
coupling said display to the output of said calculator.
13. A device according to claim 12 wherein said keyboard comprises
a plurality of flexible and resilient keys.
14. A device according to claim 13 wherein said keys are made of an
electrically conductive plastic.
15. A device according to claim 12 wherein said keyboard is made
entirely of stationary elements.
16. A device according to claim 15 wherein said keyboard comprises
an electrically conductive metallic layer on said face, said layer
including a plurality of apertures, and an electrically conductive
pin passing through said face and into each of said apertures
whereby an electrical circuit may be completed between said layer
and one of said pins by inserting an electrically conductive stylus
into one of said apertures.
17. A device according to claim 12 including a common decoder
coupling said timing circuit and said electronic calculator to said
display, said mode switch switching the input of said decoder
between the output of said timing circuit and the output of said
calculator.
18. A device according to claim 17 including a transmission gate
coupling said calculator to said decoder.
19. A device according to claim 18 wherein said mode switch is
coupled to said transmission gate.
20. A device according to claim 1, wherein said display is a liquid
crystal display.
21. A device according to claim 20, wherein said display is a field
effect liquid crystal display.
22. A device according to claim 12, wherein said display comprises
a plurality of display stations, each formed of light-emitting
diodes, a strobe signal source, and means coupling said strobe
signal source to said display for sequentially energizing at least
some of the stations of said display.
Description
This invention relates to a combination wristwatch and calculator
and more particularly to a combination solid state wrist calculator
and crystal controlled precision timepiece incorporating a
miniature keyboard array and an eight digit electro-optical digital
display in the form of a plurality of liquid crystal elements or
light emitting diodes. The time display and the calculate
operations are mutually exclusive and are selected by a mode
switch.
In recent years there have been developed a variety of new
wristwatches generally referred to as "electronic" watches. In many
instances these devices use as a timing source a crystal controlled
electronic oscillator whose frequency is divided down to produce
timing signals at a frequency of 1 Hz and less by a low power solid
state divider often incorporating complementary MOS transistors. In
some instances the wristwatches have incorporated an
electro-optical digital display in the form of liquid crystals or
light emitting diodes. A wristwatch of this general type
incorporating light emitting diodes is disclosed in assignee's U.S.
Pat. No. 3,672,155 whereas a similar wristwatch construction
utilizing a liquid crystal digital display is disclosed in
assignee's U.S. Pat. No. 3,701,249. Through the use of large-scale
integrated circuits it is possible to form most of the active
components of the wristwatch from a single large-scale integrated
circuit chip or at the most only a few chips.
Recent years have also seen the development of a new family of
electronic calculators generally referred to as pocket calculators.
These calculators have taken a wide range of forms depending upon
size and complexity but in many cases have incorporated integrated
circuitry in combination with a digital numerical display. While in
some instances the pocket calculators have been sufficiently small
to be readily held in the palm of one hand, they have in all
instances been quite large and bulky in relation to a modern sized
man's wristwatch. One of the limiting factors in further reduction
in size of a pocket calculator has been the necessity for a readily
accessible keyboard which can be easily and accurately operated
without placing undue requirements on the manual dexterity of the
operator to perform the desired mathematical calculations.
The present invention is directed to a novel wristwatch device
which combines the features of both a precision timepiece and a
very small or miniature electronic calculator. This is made
possible by combining in a novel manner certain features of the
newer type wristwatches with certain features of the so-called
pocket calculators and by providing an improved and unique
miniature keyboard on the watch face.
In the present invention time, which as used herein includes
calendar information such as the day and month of the year, is
constantly kept. This time information is displayed when desired on
the face of the watch in the form of a digital numerical display.
In the preferred embodiment the display takes the form of an eight
digit electro-optical display using two digits to display minutes,
two digits for hours, two digits for the day of the month and the
last two digits for the month of the year. By manually depressing a
mode switch on the wristwatch the calculator portion of the device
is actuated and the eight digit display made responsive to the
digital calculator circuitry. By depressing appropriate keys on the
face of the wristwatch the desired mathematical calculations are
performed by the calculator circuits within the watch and the
result is displayed on the same eight digit display previously used
to indicate time. Important features of the present invention
include the fact that time is constantly being kept in the
wristwatch even when operating in the calculate mode so that
accurate time may be displayed at any instant. In addition, when
the device is being utilized to display time, i.e., is not in the
calculate mode, the calculator circuits are de-energized so as to
minimize the power drain on the small size energy source or battery
provided in the wristwatch case. In one embodiment of the present
invention the display is formed by a plurality of liquid crystals
preferably of the newer field effect type while in a second
embodiment of the present invention the display is an active one
incorporating light emitting diodes.
It is, therefore, one object of the present invention to provide an
improved wrist calculator.
Another object of the present invention is to provide a wristwatch
incorporating a digital calculator.
Another object of the present invention is to provide an improved
wrist calculator having a novel miniaturized calculator
keyboard.
Another object of the present invention is to provide a combination
wristwatch and calculator which both share a common digital
display.
Another object of the present invention is to provide an electronic
wristwatch having a novel miniaturized calculator keyboard on the
wristwatch face.
Another object of the present invention is to provide a combination
wristwatch and calculator including a calendar time display.
Another object of the present invention is to provide a combination
wristwatch and electronic calculator incorporating a common
electro-optical display in the form of liquid crystals or light
emitting diodes.
Another object of the present invention is to provide a combination
wristwatch and electronic calculator in which time is constantly
kept and in which the calculator circuitry is only energized when
the calculate mode is selected by the wearer.
These and further objects and advantages of the present invention
will be more apparent upon reference to the following
specification, claims and appended drawings wherein:
FIG. 1 is a perspective view of a combination wristwatch and
electronic calculator constructed in accordance with the present
invention;
FIG. 2 is a block diagram of the electronic circuitry forming the
device of FIG. 1;
FIG. 3 is a perspective view of a portion of the calculator
keyboard of FIG. 1;
FIG. 4 is a cross section through a portion of the keyboard of FIG.
1;
FIG. 5 is a cross section through a modified keyboard construction
which may be used in the device of FIG. 1;
FIG. 6 is a perspective view similar to FIG. 1 showing a modified
combination wristwatch and electronic calculator constructed in
accordance with the present invention; and
FIG. 7 is a block diagram for the circuitry of the modified device
of FIG. 6.
Referring to the drawings, the novel combination wristwatch and
electronic claculator of the present invention is generally
indicated at 10 in FIG. 1 as comprising a watch case 12 to which is
attached a wristwatch band or bracelet 14. Mounted on the face 16
of the watch is an electrical digital display 18 and a calculator
keyboard 20. The display includes a four digit calendar portion 22
with the numerals 12/28 indicating the date of Dec. 28 and with a
four digital time portion 24 showing the numerals 10:37 indicating
that it is 37 minutes after 10 o'clock. Keyboard 20 is provided
with keys for the decimal numbers 0 through 9, with a decimal point
key, and with keys for addition, subtraction, multiplication and
division and additional keys for either constant or chain
operation.
In operation, the hours and minutes of time as well as day and
month of the year are continuously displayed at the display
stations 18 and appropriately advance in indication with a change
in time. The digital display stations are each preferably formed
from a plurality of liquid cyrstals either of the light scattering
type or preferably of the newer field effect type. Since liquid
crystals draw little power the time may be continuously displayed
at the display stations without unduly loading the watch battery
incorporated in the display case. When it is desired to operate the
device in a calculate mode a push button 26 mounted on the watch
case is depressed closing a switch which clears the calculator and
causes the display to display all zeros. The keyboard is then
operated to perform the desired calculation of either addition,
subtraction, multiplication or division through binary calculator
circuitry incorporated in the watch case in a well known manner.
When calculations have been completed the result appears on the
display 18 and once the result has been noted, the display may be
returned to its time display function by again depressing the push
button 26 to open the mode switch.
FIG. 2 is a detailed block diagram of the electronic circuit for
the device 10 of FIG. 1. The electronic circuit generally indicated
at 30 comprises a power source 32 which by way of example only may
comprise a pair of conventional 1 1/2 volt wristwatch batteries
connected in series to provide a nominal 3 volt power supply to the
various components of the device 10. Energized from the battery is
a time-keeping circuit generally indicated at 34 which comprises
crystal oscillator 36, a divider 38, a time circuit 40 (hours and
minutes) and a calendar circuit 42 (days and months). These
elements are connected to the positive side of the power supply 32
by respective leads 44, 46, 48 and 50. This connection is
continuous so that time is constantly being kept by the time
circuit 34 irrespective of whether time information is displayed or
the device is operating in the calculate mode. In the preferred
embodiment, oscillator 36, divider 40, time circuit 42 and calendar
circuit 44 are formed of complementary MOS transistors utilizing
large-scale integration circuit techniques. The digital display 18
in FIG. 2 is shown as connected to the positive side of the power
source through a voltage up-converter 52 which converts the three
volt output of battery 32 to the approximately 15 volts or more
necessary to drive the liquid crystal elements of the display 18.
As previously indicated, the liquid crystals draw very small
current and, therefore, may be continuously illuminated without
resulting in an undue amount of current drain from battery 32.
Battery 32 also has its positive side connected by a lead 54 to a
decoder 56 which by way of example only may be a binary coded
decimal to seven segment decoder and whose output drives the
digital display 18 by way of lead 58. Decoder 56 is preferably
formed from low power complementary MOS transistors and receives
timing information from time circuit 40 by way of lead 60 and
calendar information from calendar circuit 42 by way of lead 62.
This information passes to the decoder from the time circuit 40 and
the calendar or date circuit 42 by way of a transmission gate
circuit 68 receiving energy from the power supply over lead 72. The
time-keeping portion of the circuit 34 as well as the decoder 56
and transmission gate 68 by way of example only may be of the CMOS
type shown and described in assignee's copending application Ser.
No. 219,953 filed Jan. 24, 1972 entitled SOLID STATE WATCH WITH
CALENDAR DISPLAY.
The keys of the keyboard 20 of FIG. 1 are connected to
corresponding keyboard switches 64 of FIG. 2 which are in turn
connected to an electronic calculator circuit 66. This circuit is
preferably formed of complementary MOS transistors and is provided
with sufficient storage to perform the addition, subtraction,
multiplication and division previously described. The output of the
calculator circuit 66 which is preferably in the same BCD form as
the time and date information is passed to the transmission gate 56
over lead 70. The output from calculator 66 as well as the outputs
from time circuit 40 and calendar circuit 42 are preferably encoded
in accordance with the 8421 bcd code.
Calculator 66 and transmission gate 68 are energized from the power
supply 32 through a mode switch 74 which is actuated in response to
depression of the push button 26 of FIG. 1. When mode switch 74 of
FIG. 2 is closed, energy is supplied from the power supply 32 to
the calculator and to the gate. Closure of mode switch 74 switches
the gate so that instead of passing time information from the time
leads 60 and 62 to the decoder it passes the calculator output
information on lead 70. Depression of the keyboard keys cause the
calculator to perform the desired operation and its output which is
internally converted into 8421 bcd signals passes through decoder
56 to energize display 18 with the desired answer or result. Once
calculations are completed, push buttom 26 is again depressed
opening switch 74, de-energizing the calculator circuits and
removing the signal on lead 74 to the transmission gate so that the
decoder again displays time information from time circuit 40 and
calendar circuit 42.
FIG. 3 shows a portion of the keyboard 20 including a plurality of
keys 78 and FIG. 4 is a cross section through three of these keys.
The keys 78 are preferably formed of electrical conductive plastic
of the snap acting type having sufficient resiliency to snap back
after depression into the arcuate shape illustrated by keys 80 in
FIG. 4. By way of example only the conductive plastic for the keys
may be formed of a composition of micron-size copper particles
dispersed in a cross linked polymer classified as a conductive
polymer. Volume resistivity and thermal elasticity are a function
of the metal loading by weight. When one of the keys such as key 84
in FIG. 4 is depressed as by the end of a standard ball point pen
or similar device, the central portion of the key engages the head
of an electrically conductive pin 86 passing through the face 16 of
the watch. Similar pins 88 and 90 secure the edges of the key and
each of these pins is connected to an electrically conductive lead
92 while the center pin 86 is connected to a corresponding lead 94.
It can be seen that depression of key 84 into engagement with the
head of pin 86 establishes an electrical circuit between leads 92
and the central lead 94 so as to complete a circuit in the
calculator circuitry 66 of FIG. 2. When the key is released the
inherent resiliency of the plastic material from which it is formed
causes it to snap back into the arcuate position illustrated by the
keys 80 and 82, thus breaking the circuit to the calculator.
FIG. 5 shows a modified keyboard construction involving no moving
keys. In this embodiment the electrically insulating watch face 16
has secured to it an electrically conductive metallic layer 100
having suitable key indicia imprinted on it. This layer is
connected to the calculator circuit 66 of FIG. 2 by a common lead
102. Passing through face plate 16 of the watch are electrically
conductive pins 104, 106 and 108 and the upper ends of these pins
extend above the face plate 16 and are received in concave hollows
or cavities 110, 112, and 114 etched out of or otherwise suitably
provided in conductive metal layer 100. An electrical circuit is
completed from the common lead 102 through layer 100 to the
appropriate one of pins 104, 106 or 108 by inserting conductive
metallic stylus 116 into the appropriately labelled aperture or
cavity so that the stylus is in contact both with the metal layer
100 and with the appropriate pin such as the pin 108. This
completes a circuit to the calculator by way of lead 102 and the
corresponding one of the electrical leads 118, 120 and 122 of the
pin 104, 106 and 108.
FIG. 6 shows a modified embodiment of the combination wristwatch
and electronic calculator of the present invention with like parts
bearing like reference numerals. In the embodiment of FIG. 6 the
liquid crystal display 18 is replaced with an identical display 112
except that the display 112 employs light emitting diodes rather
than liquid crystals. That is, whereas the liquid crystal display
18 in the embodiment of FIG. 1 is a passive display, the display
112 of FIG. 6 is an active one. Furthermore, since the light
emitting diodes forming the display 112 draw a significant amount
of current from the wristwatch battery when they are illuminated,
the device 110 of FIG. 6 also incorporates a demand push button 114
so that the time information is only displayed, that is, the light
emitting diodes are only energized to display time when the push
button 114 is manually depressed.
The operation of the calculator portion of the device 110 of FIG. 6
is the same as that in the embodiment of FIG. 1 previously
described. However, in order to further conserve the energy drawn
from the battery by the light emitting diodes in the embodiment of
FIG. 6, the diode stations forming the display 112 are preferably
strobed so that only two digits of the time display are on at any
one time. However, this strobing is at a sufficiently high rate or
sufficiently high frequency so as to give the appearance of a
continuous light emitting display at all stations whenever the
demand push button 114 is depressed. FIG. 7 shows an overall block
diagram of the electrical circuit for the embodiment of FIG. 6
including the arrangement for strobing the light emitting diode
display 112. Reference made be had to assignee's copending
application Ser. No. 219,956 filed Jan. 24, 1972 for a detailed
disclosure of an arrangement for strobing a light emitting diode
time display which may be utilized in the embodiment of FIGS. 6 and
7 of this invention.
Briefly, with reference to FIG. 7, the crystal oscillator 36 is
connected to the time and date circuits 118 which correspond to the
time circuit 40 of FIG. 2 and the calendar circuit 42 of FIG. 2 but
which in the embodiment of FIG. 7 are combined into the single
circuit 118. Again the circuit is preferably formed of large-scale
integrated circuits comprising as active elements only
complementary symmetry MOS transistors. The time information in
binary coded decimal form according to an 8421 bcd code is supplied
to the combined switching, decoding, and logic circuits 120 again
formed solely of active elements in the form of CMOS. Also forming
a part of the LSI time and data circuit 118 of FIG. 7 is the CMOS
divider 38 of FIG. 2 and from this divider is derived a clock
strobe pulse signal generally indicated in FIG. 7 by the clock
strobe pulse source 122 feeding a strobe pulse into circuit 120.
The strobe pulses generated in circuit 120 are applied by lines 124
to strobe the display 112. Timing information in suitable form for
driving a seven bar segment array of light emitting diodes at each
station is supplied to the display over leads 126. These are
applied through discrete bipolar driver transistors 128 to the
eight stations of the display 112. The keyoard and mode circuit 130
operates in the manner previously described in conjunction with the
embodiment of FIG. 1 as does the LSI calculator circuit 132. As in
the previous embodiment when the mode button 26 of FIG. 6 is
depressed, the calculator circuit is energized, the calculator
memories are cleared, and the light emitting diode display stations
are all energized to display a zero at each station. The desired
problem is inserted by the keyboard and the result of the addition,
subtraction, multiplication or division is numerically displayed by
the eight digit display station 112. When the calculation is
completed and the result noted the push button 26 of FIG. 6 is
again depressed opening the mode switch, de-energizing the
calculator portion of the device and switching the decode circuit
over to receive the input from the combination time and date
circuit 118. As previously indicated in the embodiment of FIGS. 6
and 7 although timing information is supplied to the display, the
display is not actually energized to display timing information
until the demand button 114 of FIG. 6 is depressed.
It is apparent from the above that the present invention provides
an improved wrist calculator and in particular provides a wrist
device which combines the features of both a wristwatch or
timepiece and a miniature calculator. Important features of the
present invention include a novel miniature keyboard which is
incorporated on a wristwatch case and also includes the utilization
of common decoding circuitry for displaying both time and the
results of mathematical calculations. Since all active electrical
elements of the combined device with the exception of the bipolar
drivers for the light emitting diode display in the embodiment of
FIGS. 6 and 7 are preferably formed of complementary symmetry MOS
transistors, substantially the entire electrical circuitry for the
device of this invention may be formed using large-scale integrated
circuit techniques and may consist of only one or at the msot only
a few large-scale integrated circuit chips. The use of
complementary symmetry MOS transistors insures that there is only a
small power drain on the wristwatch battery forming the sole power
supply for the device since complementary symmetry MOS transistors
draw only a minimum amount of current. Based upon a normal number
of operations per day a conventional two cell wristwatch battery
should have a life in the device of the present invention of from 6
months up to as much as a year and one half before it need be
replaced.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiments are therefore to be considered in all respects
as illustrative and not restrictive, the scope of the invention
being indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *