Coin counting calculator

An electronic calculator allows a user to quickly add up change. The user simply pushes one of the coin switches clearly marked to represent a particular coin denomination in order to add up the change. Each time a coin switch is activated, an accumulated sum is incremented by a value associated with the value of the coin denomination represented by the activated coin switch. The accumulated sum is then displayed to the user. If the user depresses the wrong coin switch, an error switch is provided which subtracts the previous entry made from the tabulated sum to arrive at the tabulated sum previous to the depression of the coin switch.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to electronic calculators used for tabulating 
a total sum of money. More particularly, the present invention pertains to 
those electronic calculators having coin push buttons dimensioned to have 
a diameter substantially equivalent to the diameter of a particular coin 
denomination and used to increment a displayed number by the value 
associated with that particular coin denomination. 
2. Description of the Prior Art 
Devices for the tabulation of money have been proposed for specialized 
purposes, e.g., education or balancing a checkbook. Electrical calculators 
designed for the purpose of tabulating money include desk top units or 
portable units small enough to fit into a checkbook. Mechanical devices 
for the tabulation of money include games, calculators, cash registers, 
and others. 
U.S. Pat. No. 4,959,017 issued Sep. 25, 1990 to Barbara J. Thompson et al 
discloses an electronic calculating device for teaching user of the device 
how to handle money. The device has several programs to provide a variety 
of question and answer sessions to the user. 
U.S. Pat. No. 4,308,588 issued Dec. 29, 1981 to John T. Siwula discloses a 
portable calculator for balancing a checkbook. One of the features of the 
device allows tile user to key-in a monetary amount and perform a "trial 
balance" operation which updates the remainder of the user's balance for 
each entry. 
U.S. Pat. No. 3,488,864 issued Jan. 13, 1970 to Catherine T. McManus 
discloses a mechanical device for improving the monetary skills of the 
user. The device is designed to receive ten pennies located above two 
nickels located above one dime. 
U.S. Pat. No. 4,571,189 issued Feb. 18, 1986 to Spencer L. Shank discloses 
a board using overlays having a predetermined number of printed coins 
thereon for allowing a user to count the printed coins and associate a 
predetermined number of coins with another single coin or paper bill 
printed thereon. 
None or the above inventions and patents, taken either singly or in 
combination, is seen to describe the instant invention as claimed. 
SUMMARY OF THE INVENTION 
The coin counting calculator of the present invention is used for 
tabulating coins in incremental steps associated with the value of the 
individual denominations of the coins. The calculator includes a plurality 
of coin pushbuttons, each one thereof representing the magnitude of the 
value of a particular coin denomination. A display, preferably a liquid 
crystal (LCD) display is used to indicate the tabulated sum of money. Each 
time a particular coin pushbutton is depressed, the tabulated sum is 
incremented by the value of the coin denomination that particular coin 
pushbutton represents. A clear button resets the calculator and an error 
button decrements the tabulated sum by the value of the previous entry so 
as to subtract the last entry from the tabulated sum. The calculator also 
has a display select switch to change the format of the display. The 
calculator is preferably solar powered. 
Accordingly, it is a principal object of the invention to provide a 
handheld portable coin calculator which is easily transported. 
It is another object of the invention to provide such a calculator which is 
easily tabulates coins by pushing one button. 
It is a further object of the invention to provide pushbuttons readily 
identifiable with a particular coin denomination. 
Still another object of the invention is to allow the user to change the 
format used by the display in indicating the amount of the tabulated sum. 
It is an object of the invention to provide improved elements and 
arrangements thereof in an apparatus for the purposes described which is 
inexpensive, dependable and fully effective in accomplishing its intended 
purposes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As illustrated in FIG. 1, the coin counting calculator 1 has a top face 2 
including a plurality of pushbuttons 3 located thereon, each one 
representing a particular coin denomination. A first pushbutton 3a 
represents a magnitude of the value of a penny, e.g. one cent. A second 
pushbutton represents a magnitude of the value of a nickel, e.g. five 
cents. Likewise, the pushbuttons 3c and 3d represent magnitude associated 
with the value of a dime and a quarter, respectively, e.g. ten and 
twenty-five cents. The coin counting calculator 1 is preferably powered by 
solar cell 7 when exposed to light. Alternatively, or in addition to the 
solar cell 7, an electric battery may be included in the calculator 1 as 
the sole or as the alternate power source. If both solar cell 7 and a 
battery are included in the coin counting calculator 1, a switch would 
have to be provided for selecting between the two alternate power sources. 
Each time one of the pushbuttons 3 is depressed, a tabulated sum is 
incremented by a step value equal to the magnitude of the value of the 
coin denomination that particular pushbutton 3 represents. This tabulated 
sum is indicated by the display 5. As shown in FIG. 1, the sum of 
twenty-five cents is displayed. This may be accomplished by the first 
depression of pushbutton 3d after the calculator is cleared, by the fifth 
depression of the pushbutton 3b after the calculator is cleared, or by any 
other combination of depressions of the pushbuttons 3 which result in a 
sum of twenty-five cents. Note that it is not necessary for the user to 
depress any other button to tabulate an amount of change, i.e. an 
additional function button is not required to be depressed in order to 
tabulate the sum indicated on display 5. 
A clear button 9 is used to reset the tabulated sum back to zero. Further, 
an error pushbutton 11 is used to decrement the tabulated sum by the value 
previously tabulated thereto. In this manner, if the user makes a mistake 
by depressing the wrong coin pushbutton 3, the user need only depress the 
error pushbutton 3 to arrive at the tabulated sum before he or she made 
the mistake. As illustrated in FIG. 3, a display select pushbutton 13 is 
used to alternate the format of displaying the tabulated sum. Each of the 
pushbuttons of the pushbuttons 9, 11, and 13 are marked with a symbol 
easily associating each with their respective function. The clear 
pushbutton 9 has a "C" printed thereon, the error pushbutton 11 has an "E" 
printed thereon, and the display select switch 13 has the ying-yang symbol 
printed thereon. In this manner the user can readily identify the function 
of each pushbutton 9, 11, and 13. 
The display 5 as illustrated in FIG. 1, depicts one format for displaying 
the tabulated sum. The same display 5 illustrated in FIG. 2 depicts an 
alternate display format for indicating the tabulated sum. As stated 
above, alternating between one display format or the other display format 
is accomplished by depressing the pushbutton 13. The ying-yang symbol is 
printed on the pushbutton 13 to readily illustrate that alternating 
feature of the display select button 13. 
In the preferred embodiment, the pushbuttons 3 each have an attachment 
means associated therewith, e.g. raised edges, for allowing the user to 
securely place a coin thereover to readily identify the coin denomination 
associated with the particular pushbutton 3. In this manner, a penny may 
be placed over the pushbutton 3a, a nickel over pushbutton 3b, a dime over 
pushbutton 3c, and a quarter over pushbutton 3d. Alternatively, artificial 
coins or labels may be securely attached over each of the pushbuttons 3. 
FIG. 3 illustrates the electronic circuitry needed to perform the 
operations identified above. A microprocessor 15 is used as the central 
controller of all operations and contains the necessary memory and 
software needed to carry out the operations described above. More 
specifically, the microprocessor contains step value buffers for storing 
in specific locations the individual magnitudes representing the value of 
each of the coin denominations depicted by the coin pushbuttons 3. In this 
manner a particular step value buffer has the value one stored therein, 
another step value buffer has the value five stored therein, and two other 
step value buffers have the values of ten and twenty-five stored therein. 
The microprocessor 15 also has a buffer for storing the tabulated sum. 
Upon depression of one of the coin pushbuttons 3, the value represented by 
the magnitude of the coin denomination represented by that pushbutton 3 is 
added to the tabulated sum through the use of a conventional arithmetic 
logic unit, A.L.U 17. 
As described above, each of the function buttons 21, e.g. clear pushbutton 
9, error pushbutton 11, and display select pushbutton 13, also control the 
display 5. A previous value input buffer is used to store the appropriate 
value represented by the magnitude of the value of the coin denomination 
represented by a particular coin pushbutton 3 upon the depression of that 
pushbutton 3. As stated above, the tabulated sum is incremented by the 
appropriate value upon the depression of that particular pushbutton 3. In 
this manner, if the error pushbutton 11 is depressed directly afterwards, 
the microprocessor outputs the data in the previous value input buffer to 
the A.L.U. 17 along with the tabulated sum so as to subtract the data in 
the previous value input buffer from the tabulated sum. The output of the 
A.L.U. 17 is then stored in the memory location designated for the 
tabulated sum so that the new value thereof reflects that value before the 
depression of the previously depressed coin pushbutton 11. 
It is to be understood that the present invention is not limited to the 
sole embodiment described above, but encompasses any and all embodiments 
within the scope of the following claims.