CA1159571A - Electronic calculator - Google Patents
Electronic calculatorInfo
- Publication number
- CA1159571A CA1159571A CA000365358A CA365358A CA1159571A CA 1159571 A CA1159571 A CA 1159571A CA 000365358 A CA000365358 A CA 000365358A CA 365358 A CA365358 A CA 365358A CA 1159571 A CA1159571 A CA 1159571A
- Authority
- CA
- Canada
- Prior art keywords
- unit
- display
- inch
- conversion
- metric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Calculators And Similar Devices (AREA)
- Digital Computer Display Output (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention discloses a compact electronic calculator having controller for displaying the numerical information before and after unit conversion together with respective unit symbols by means of two numerical display units and capable of displaying said unit symbols by means of the combinations of display elements.
The present invention discloses a compact electronic calculator having controller for displaying the numerical information before and after unit conversion together with respective unit symbols by means of two numerical display units and capable of displaying said unit symbols by means of the combinations of display elements.
Description
g 57 ~
The present invention relates to an improvement in a desk-top or compact electronic calculator capable of con-version bet~een different unit systems of length, weight, etc.
An electronic calculator of conventional structure has a double key function system in which unit~cbnver-sion is achieved by pressing a conversion key 4 from the Imperial or the U. S. customary systems (referred to for convenience as the inch system) to metric system or another conversion key 5 from metric system to inch system after the figure to be converted is entered from the keyboard or is displayed on the display unit as the result of the cal-culation instructed by the keyboard, and then pressing a key in the keyboard corresponding to the desired unit con-version, whereby the displayed figure is multiplied ordivided by a determined conversion factor to display a con-verted figure in the desired unit system.
Such unit conversion calculato~s as explained above have eliminated the cumbersome operation associated with the conventional unit conversion table. As an example, in case of conversion from inch to centimeter with such a conversion table, it has been necessary to establish that 1 inch = 2.54 cm, and to multiply the desired figure by
The present invention relates to an improvement in a desk-top or compact electronic calculator capable of con-version bet~een different unit systems of length, weight, etc.
An electronic calculator of conventional structure has a double key function system in which unit~cbnver-sion is achieved by pressing a conversion key 4 from the Imperial or the U. S. customary systems (referred to for convenience as the inch system) to metric system or another conversion key 5 from metric system to inch system after the figure to be converted is entered from the keyboard or is displayed on the display unit as the result of the cal-culation instructed by the keyboard, and then pressing a key in the keyboard corresponding to the desired unit con-version, whereby the displayed figure is multiplied ordivided by a determined conversion factor to display a con-verted figure in the desired unit system.
Such unit conversion calculato~s as explained above have eliminated the cumbersome operation associated with the conventional unit conversion table. As an example, in case of conversion from inch to centimeter with such a conversion table, it has been necessary to establish that 1 inch = 2.54 cm, and to multiply the desired figure by
2.54 in order to obtain the value in centimeters.
In such a calculator, however, the figure shown on : ' , '~ ' : ' ,. , 1 ~5957~
the display unitis undefinedbothwhenenteredfromthekey-board or when converted from inch system to metric system or from metric system to inch system and cannot therefore be identified by persons other than the operator or even by the operator if he interrupts the operation for a while.
The object of the present invention is to provide a calculator not associated with the aforementioned draw-backs and capable of simultaneously displaying the figures before and after the conversion together with the unit symbols, thus providing accurate and convenient information to the operator.
Also the unit symbols are displayed by the combina-tion of segment elements whereby the number of drive sig-nals for driving the display unit can be decreased topermit an inexpensive circuit structure.
- In -the drawings:-Figure 1 is an external view of a conventional unit conversion calculator with a keyboard 2, a display unit 3, an '.inch:' metric conversion.key 4 and a metric-'inch' con-version-key 5;
Figure 2 is an external view of the calculator em-bodying the present invention provided with a display unit 9 of the present invention having a metric display unit 7 and an 'inch' display unit 8;
Figure 3 is an example of unit conversions applicable both in the conventional calculator and in the calculator ~, ., . ~ ,~
': :
' :1 15957~
of the present invention;
Figure 4A is a detailed view of the display by the display unit 9 provided with a metric numeric display sec-tion 12, an 'inch' numeric display section 13, a metric unit symbol display section 10 and an 'inch' unit symbol display section 11;
Figures 4B and 4C are detailed views of the unit symbol display sections,provided with display segments for indicating degree 101; Celsius and milliliter 102; milli-liter and centimeter 103; centimeter, meter, kilometer,square meter and cubic meter 104; second power 105; third power 106; kilometer and kilogram 107; gram and kilogram 108; liter 109; U.S. unit system 110; degree 111; Fahren-heit, foot,square foot,cubic foot and fluid amount 112;
foot 113; second power 114, third power 115; gallon 116;
U.K. (Imperial) unit system 117; weight or fluid ounce 118;
inch, square inch and cubic inch 119; mile 120 and pound 121;
Figures 5A to 5F are views showing examples of dis-plays in response to various key actuations;
Figure 6 is a block diagram of an embodlment of the present invent.ion where 21 is an operation circuit, 22 is a read-only memory (ROM), 23 and 24 are registers, 25 and 26 are decoders, 27 and 28 are display drivers; and Figure 7 is a list of displays of unit symbols in an embodiment of the present invention.
Fig. 1 shows an example of the electronic calculator , , , ~:
: ~.
9 5 '7 ~!
of the conventional structure with a double key function system in which unit conversion is achieved by pressing a conversion key 4 from inch system to metric system or another conversion key 5 from metric system to inch system after the figure to be converted is entered from the key-board 2 or is displayed on the display unit 3 as the re-sult of a calculation instructed by the keyboard 2, and then pressing a key in said keyboard 2 corresponding to the desired unit conversion, whereby the displayed figure is multiplied or divided by a determined conversion factor to display a converted figure in the desired unit system.
Fig. 3 lists the unit conversions in correspondence to the numeral keys in the example shown in Fig. 1.
Such a unit conversion calculator as explained above has eliminated the cumbersome operation associated with the conventional unit conversion table. As an example, in case of conversion from inch to centimeter with such con-version table, it had been necessary to establish the relationship 1 inch = 2.54 cm, and to multiply by this figure in order to obtain the value ~n ~entimeters.
In such a calculator, however, the figure shown on the display unit 3 is undefined both when ent~red from the keyboard 2 or when converted from inch system to metric system or from metric system to inch system and cannot therefore be identified by a person other than the operator or even by the operator if he interrupts the operation for a while. Also in such calculator, erroneous manipulation ,~
, ~ ~
~95'7'~
a~a -is not detectable. For example, in case of a conversion from inches to centimeters, if the operator erroneously actuates the key '8' instead of the correct key '7' in the example shown in Fig. 3, the conversion is conducted with a conversion factor of 1 ft = 0.3048m for converting feet into meters in the place of the correct factor of 1 in =
2.54 cm, thus providing a false result. The fact that the inch syst~m contains mutually similar units such as U. S.
units and U. K. units or weight and fluid ounces has tended to increase the possibility of erroneous operations.
Fig. 2 is an external view of the electronic calcu-lator embodying the present invention, of which keyboard 2 is capable of calculations and unit conversions the same as those in the aforementioned conventional calculator, as listed in Fig. 3.
On the other hand the display unit 9 embodying the ...
.,"~
-~ ~ , . ' 1 present invention is composed of two display units, i.e. a metric display unit 7 and an inch display unit 8, as detailedly~
shown in FigO 4A. Numeral display sections 12, 13 of said display units 7, 8 perform 7-segment numeral display in the same manner as in the conventional electronic calculators.
A metric unit symbol display section 10 is composed, in the present embodiment, of 9 segments 101 - 109 as shown in Fig. 4B
Similarly an inch unit symbol display section 11 in the present embodiments is composed of 12 segments 110 - 121 as shown in Fig. 4C. The function of said display uni~s 7, 8 is detailedly shown in Fig. 5.
At first there is given an example of converting 12.5 U.S. fluid ounces into c.c. (milliliters) in metric system. Fig. 5A shows a state after a figure "12.5" is entered from the keyboard 2 shown in Fig. 2. In this state the unit symbol is not displayed as there has been conducted numeral entry alone. Successively the inch to metric conversion key 4 is actuated to assume the conversion mode. Fig. 5B shows the display in this state, in which the figure "12.5" is displayed in the inch display unit 8 as in Fig. 5A, since the entered figure of the figure before conversion belongs to the inch system as the intended conversion is from the inch system to the metric system. Then the conversion is completed by actuating a key "6" for converting fluid ounce into c.c.
(milliliter), whereupon the result of conversion is displayed . : :
.
:
as shown in Fig. 5C. The display includes a figure "369.675"
obtained by converting 12.5 U.S. fluid ounces into milliliters and corresponding unit symbols "cc" in the metric display unit 7, and the figure "12.5" before conversion and correspond-ing unit symbols "usfoz" indicating U.S. fluid ounces in the inch display unit ~.
In this state, segments 102 and 103 in the metric unit symbol display section 10 are selected to indicate "cc"
while, in the inch unit symbol display section 11, segments 110, 112 and 11~ are selected to display "usfoz".
In the following there will be given an example of converting 7.5 square meters into s~uare feet in the inch system. In the similar manner as explained in the foregoing, Fig. 5D shows the state of display after a figure "7.5" is entered from the keyboard 2. Successively the conversion key 5 is actuated to assume the conversion mode from the metric system to the inch system. Fig. 5E shows the display in this state, in which the entered figure belonging to the metric system is now transferred to the metric display unit 7.
Successively the conversion is completed by actuating a key "5" for converting square meters into square feet, whereupon the display assumes a state shown in Fig. 5F, in which the inch display unit ~ shows a converted figure "~0. 731969" and corresponding unit symbols "ft" indicating square feet, while the metric display unit 7 shows the original figure "7.5" and 115957~
corresponding unit symbols "m2" indieating square meters.
In the ineh unit symbol display seetion 11, the segments 112, 113 and 114 are seleeted to display "ft2", while in the metrie ¦
unit symbol display section 10 the segments 104 and 105 are seleeted to display "m2l' Fig. 6 is a block diagram of the calculator shown in Fig. 2, in which the numeric information and conversion instructions entered from the keyboard 2 are processed in an operation cireuit 21 according to the programs or conversion factors stored in a read-only memory 22/ and stored in register 3 23, 24 respectively for numeric and unit data of metric system and inch system. Such numeric and unit data are respectively converted by a metric decoder 25 and an inch decoder 26 into the signals for display and supplied to the display units 7, 8 through display drivers 27, 28. The numeral display sections perform 7-segment decimal display, while the unit symbol display seetions perform 9-segment display and 12-segmen t display respectively in the metric system and in the inch system. Naturally the display in the display unit 9 varies in the known manner corresponding to the content of the memory registers aceording to the instructions from the keyboar 2.
Fig. 7 shows the examples of unit symhols displayed for the unit conversions shown in Figs. 2 and 3. Although 26 symbols are required for covering the unit conversions shown '~
~ , , ll~g571 1 li in Fig. 3, the present invention employs only 21 siynals to perform corresponding displays through segment display method.
More specifically, in the metric unit symbol display section, 12 different unit symbols are represented by 9 segments. As shown in Fig. 4B, the segment 102 represents "C" in combinatio~
with the segment 101, and "CC" in combination with the segment 103. Also the segment 102 performs plural functions of representing 'Icm'' in combination with the segment 103, "km"
in combination with the segment 107, "cm2" in combination with the segments 103 and 105, I'cm3l' in combination with the segments 103 and 106, 'Im2'' in combination with the segment 105, and 'Im3'l in combination with the segment 106. Such combined displays allow to reduce the number of drive signals in the circuit structure and are advantageous in avoiding the limitation resulting from the dimension or pin number of the large-scale integrated circuit and also in realizing, for example in a liquid crystal display unit, larger display symbols for a display unit of determined dimension.
As detailedly explained in the foregoing, the electroni calculator of the present invention, capable of displaying the converted figure of length, weight, area, volume or the like together with the corresponding unit symbols, not only provides readily understandable numeric information but also allows the operator to avoid the errors resulting from the use of double function keys or from the presence of mutually '~ .
1 resembling units, and to avoid the necessity of repeating the conversion from the beginning even when the calculation is interrupted for a while since the displayed figures are always associated with the corresponding unit symbols.
In such a calculator, however, the figure shown on : ' , '~ ' : ' ,. , 1 ~5957~
the display unitis undefinedbothwhenenteredfromthekey-board or when converted from inch system to metric system or from metric system to inch system and cannot therefore be identified by persons other than the operator or even by the operator if he interrupts the operation for a while.
The object of the present invention is to provide a calculator not associated with the aforementioned draw-backs and capable of simultaneously displaying the figures before and after the conversion together with the unit symbols, thus providing accurate and convenient information to the operator.
Also the unit symbols are displayed by the combina-tion of segment elements whereby the number of drive sig-nals for driving the display unit can be decreased topermit an inexpensive circuit structure.
- In -the drawings:-Figure 1 is an external view of a conventional unit conversion calculator with a keyboard 2, a display unit 3, an '.inch:' metric conversion.key 4 and a metric-'inch' con-version-key 5;
Figure 2 is an external view of the calculator em-bodying the present invention provided with a display unit 9 of the present invention having a metric display unit 7 and an 'inch' display unit 8;
Figure 3 is an example of unit conversions applicable both in the conventional calculator and in the calculator ~, ., . ~ ,~
': :
' :1 15957~
of the present invention;
Figure 4A is a detailed view of the display by the display unit 9 provided with a metric numeric display sec-tion 12, an 'inch' numeric display section 13, a metric unit symbol display section 10 and an 'inch' unit symbol display section 11;
Figures 4B and 4C are detailed views of the unit symbol display sections,provided with display segments for indicating degree 101; Celsius and milliliter 102; milli-liter and centimeter 103; centimeter, meter, kilometer,square meter and cubic meter 104; second power 105; third power 106; kilometer and kilogram 107; gram and kilogram 108; liter 109; U.S. unit system 110; degree 111; Fahren-heit, foot,square foot,cubic foot and fluid amount 112;
foot 113; second power 114, third power 115; gallon 116;
U.K. (Imperial) unit system 117; weight or fluid ounce 118;
inch, square inch and cubic inch 119; mile 120 and pound 121;
Figures 5A to 5F are views showing examples of dis-plays in response to various key actuations;
Figure 6 is a block diagram of an embodlment of the present invent.ion where 21 is an operation circuit, 22 is a read-only memory (ROM), 23 and 24 are registers, 25 and 26 are decoders, 27 and 28 are display drivers; and Figure 7 is a list of displays of unit symbols in an embodiment of the present invention.
Fig. 1 shows an example of the electronic calculator , , , ~:
: ~.
9 5 '7 ~!
of the conventional structure with a double key function system in which unit conversion is achieved by pressing a conversion key 4 from inch system to metric system or another conversion key 5 from metric system to inch system after the figure to be converted is entered from the key-board 2 or is displayed on the display unit 3 as the re-sult of a calculation instructed by the keyboard 2, and then pressing a key in said keyboard 2 corresponding to the desired unit conversion, whereby the displayed figure is multiplied or divided by a determined conversion factor to display a converted figure in the desired unit system.
Fig. 3 lists the unit conversions in correspondence to the numeral keys in the example shown in Fig. 1.
Such a unit conversion calculator as explained above has eliminated the cumbersome operation associated with the conventional unit conversion table. As an example, in case of conversion from inch to centimeter with such con-version table, it had been necessary to establish the relationship 1 inch = 2.54 cm, and to multiply by this figure in order to obtain the value ~n ~entimeters.
In such a calculator, however, the figure shown on the display unit 3 is undefined both when ent~red from the keyboard 2 or when converted from inch system to metric system or from metric system to inch system and cannot therefore be identified by a person other than the operator or even by the operator if he interrupts the operation for a while. Also in such calculator, erroneous manipulation ,~
, ~ ~
~95'7'~
a~a -is not detectable. For example, in case of a conversion from inches to centimeters, if the operator erroneously actuates the key '8' instead of the correct key '7' in the example shown in Fig. 3, the conversion is conducted with a conversion factor of 1 ft = 0.3048m for converting feet into meters in the place of the correct factor of 1 in =
2.54 cm, thus providing a false result. The fact that the inch syst~m contains mutually similar units such as U. S.
units and U. K. units or weight and fluid ounces has tended to increase the possibility of erroneous operations.
Fig. 2 is an external view of the electronic calcu-lator embodying the present invention, of which keyboard 2 is capable of calculations and unit conversions the same as those in the aforementioned conventional calculator, as listed in Fig. 3.
On the other hand the display unit 9 embodying the ...
.,"~
-~ ~ , . ' 1 present invention is composed of two display units, i.e. a metric display unit 7 and an inch display unit 8, as detailedly~
shown in FigO 4A. Numeral display sections 12, 13 of said display units 7, 8 perform 7-segment numeral display in the same manner as in the conventional electronic calculators.
A metric unit symbol display section 10 is composed, in the present embodiment, of 9 segments 101 - 109 as shown in Fig. 4B
Similarly an inch unit symbol display section 11 in the present embodiments is composed of 12 segments 110 - 121 as shown in Fig. 4C. The function of said display uni~s 7, 8 is detailedly shown in Fig. 5.
At first there is given an example of converting 12.5 U.S. fluid ounces into c.c. (milliliters) in metric system. Fig. 5A shows a state after a figure "12.5" is entered from the keyboard 2 shown in Fig. 2. In this state the unit symbol is not displayed as there has been conducted numeral entry alone. Successively the inch to metric conversion key 4 is actuated to assume the conversion mode. Fig. 5B shows the display in this state, in which the figure "12.5" is displayed in the inch display unit 8 as in Fig. 5A, since the entered figure of the figure before conversion belongs to the inch system as the intended conversion is from the inch system to the metric system. Then the conversion is completed by actuating a key "6" for converting fluid ounce into c.c.
(milliliter), whereupon the result of conversion is displayed . : :
.
:
as shown in Fig. 5C. The display includes a figure "369.675"
obtained by converting 12.5 U.S. fluid ounces into milliliters and corresponding unit symbols "cc" in the metric display unit 7, and the figure "12.5" before conversion and correspond-ing unit symbols "usfoz" indicating U.S. fluid ounces in the inch display unit ~.
In this state, segments 102 and 103 in the metric unit symbol display section 10 are selected to indicate "cc"
while, in the inch unit symbol display section 11, segments 110, 112 and 11~ are selected to display "usfoz".
In the following there will be given an example of converting 7.5 square meters into s~uare feet in the inch system. In the similar manner as explained in the foregoing, Fig. 5D shows the state of display after a figure "7.5" is entered from the keyboard 2. Successively the conversion key 5 is actuated to assume the conversion mode from the metric system to the inch system. Fig. 5E shows the display in this state, in which the entered figure belonging to the metric system is now transferred to the metric display unit 7.
Successively the conversion is completed by actuating a key "5" for converting square meters into square feet, whereupon the display assumes a state shown in Fig. 5F, in which the inch display unit ~ shows a converted figure "~0. 731969" and corresponding unit symbols "ft" indicating square feet, while the metric display unit 7 shows the original figure "7.5" and 115957~
corresponding unit symbols "m2" indieating square meters.
In the ineh unit symbol display seetion 11, the segments 112, 113 and 114 are seleeted to display "ft2", while in the metrie ¦
unit symbol display section 10 the segments 104 and 105 are seleeted to display "m2l' Fig. 6 is a block diagram of the calculator shown in Fig. 2, in which the numeric information and conversion instructions entered from the keyboard 2 are processed in an operation cireuit 21 according to the programs or conversion factors stored in a read-only memory 22/ and stored in register 3 23, 24 respectively for numeric and unit data of metric system and inch system. Such numeric and unit data are respectively converted by a metric decoder 25 and an inch decoder 26 into the signals for display and supplied to the display units 7, 8 through display drivers 27, 28. The numeral display sections perform 7-segment decimal display, while the unit symbol display seetions perform 9-segment display and 12-segmen t display respectively in the metric system and in the inch system. Naturally the display in the display unit 9 varies in the known manner corresponding to the content of the memory registers aceording to the instructions from the keyboar 2.
Fig. 7 shows the examples of unit symhols displayed for the unit conversions shown in Figs. 2 and 3. Although 26 symbols are required for covering the unit conversions shown '~
~ , , ll~g571 1 li in Fig. 3, the present invention employs only 21 siynals to perform corresponding displays through segment display method.
More specifically, in the metric unit symbol display section, 12 different unit symbols are represented by 9 segments. As shown in Fig. 4B, the segment 102 represents "C" in combinatio~
with the segment 101, and "CC" in combination with the segment 103. Also the segment 102 performs plural functions of representing 'Icm'' in combination with the segment 103, "km"
in combination with the segment 107, "cm2" in combination with the segments 103 and 105, I'cm3l' in combination with the segments 103 and 106, 'Im2'' in combination with the segment 105, and 'Im3'l in combination with the segment 106. Such combined displays allow to reduce the number of drive signals in the circuit structure and are advantageous in avoiding the limitation resulting from the dimension or pin number of the large-scale integrated circuit and also in realizing, for example in a liquid crystal display unit, larger display symbols for a display unit of determined dimension.
As detailedly explained in the foregoing, the electroni calculator of the present invention, capable of displaying the converted figure of length, weight, area, volume or the like together with the corresponding unit symbols, not only provides readily understandable numeric information but also allows the operator to avoid the errors resulting from the use of double function keys or from the presence of mutually '~ .
1 resembling units, and to avoid the necessity of repeating the conversion from the beginning even when the calculation is interrupted for a while since the displayed figures are always associated with the corresponding unit symbols.
Claims (2)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electronic calculator, comprising:
two numeric display units; and control means adapted for displaying numeric information before unit conversion and numeric information after unit conversion together with corresponding unit symbols respectively on said two numeric display units.
two numeric display units; and control means adapted for displaying numeric information before unit conversion and numeric information after unit conversion together with corresponding unit symbols respectively on said two numeric display units.
2. An electronic calculator according to the claim 1, wherein said display of unit symbols is performed by combinations of display elements.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15899579A JPS5680758A (en) | 1979-12-06 | 1979-12-06 | Electronic desk-top calculator |
| JP158995/1979 | 1979-12-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1159571A true CA1159571A (en) | 1983-12-27 |
Family
ID=15683917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000365358A Expired CA1159571A (en) | 1979-12-06 | 1980-11-24 | Electronic calculator |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5680758A (en) |
| CA (1) | CA1159571A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS642182Y2 (en) * | 1981-05-12 | 1989-01-19 |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5214115A (en) * | 1975-07-23 | 1977-02-02 | Mazda Motor Corp | Suction device of rotary piston engine |
| JPS5347251A (en) * | 1976-10-12 | 1978-04-27 | Seiko Epson Corp | Calculator |
-
1979
- 1979-12-06 JP JP15899579A patent/JPS5680758A/en active Pending
-
1980
- 1980-11-24 CA CA000365358A patent/CA1159571A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5680758A (en) | 1981-07-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4744044A (en) | Hand-held calculator for dimensional calculations | |
| US4545022A (en) | Fractional calculator | |
| US4481598A (en) | Electronic equipment having a second function keying system | |
| US4100602A (en) | Recipe conversion calculator | |
| CA1159571A (en) | Electronic calculator | |
| JPS55147755A (en) | Electronic type cash register | |
| US4290113A (en) | Minicomputer | |
| US4511987A (en) | Method of entering and performing operations on complex numbers on calculators | |
| US4538501A (en) | Electronic musical chord calculator | |
| US4473886A (en) | Data processing apparatus with algebraic memory operation and entry sequence | |
| JPS6356581B2 (en) | ||
| US4266623A (en) | Price calculating balance with aimed price input | |
| JPS5912670Y2 (en) | shopping calculator | |
| US4495592A (en) | Electronic data processing apparatus with equation operating system having implied multiplication of two hierarchical ranks | |
| JPH021627Y2 (en) | ||
| JPS5559542A (en) | Display system for computer or the like | |
| JPS5935265A (en) | Electronic calculator | |
| JPS6030949B2 (en) | electronic desk calculator | |
| JPH035956Y2 (en) | ||
| JPS61267855A (en) | Electronic equipment | |
| JPH054044Y2 (en) | ||
| JPS6284846U (en) | ||
| JPS642182Y2 (en) | ||
| JPS6117482Y2 (en) | ||
| JP3071528U (en) | Calculator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |