This compilation Copyright (C) 2005 Mike Sebastian. No copyright claim is made to original U.S. Government works.
| U.S. Patent No. | Assignee | File Date | Issue Date | Inventor1 | Product | Title | Comments |
| 3021066 | Kienzle Apparate G.m.b.H. | December 17, 1956 | February 13, 1962 | Martens | - | Electronic calculator | Floating decimal-point calculation |
| 3380031 | Control Data Corp. | August 10, 1965 | April 23, 1968 | Clayton | - | Remote calculator | - |
| 3676656 | General Electric Co. | June 30, 1969 | July 11, 1972 | Schmidt | - | Electronic digital slide rule | Not traditional calculator architecture |
| 3803834 | Time Computer, Inc. | February 6, 1973 | April 16, 1974 | Reese | - | Wristwatch calculator | - |
| 3881807 | Kabushiki Kaisha Suwa Seikosha | November 12, 1970 | May 6, 1975 | Hosokawa | - | Liquid crystal display for small-sized electronic calculator | Display cover to reflect light onto LCD |
| 3911234 | AMP Inc. | July 5, 1973 | October 7, 1975 | Kotaka | - | Keyboard type switch assembly having fixed and moveable contacts disposed on foldable flexible printed circuit board | - |
| 3911424 | IBM | September 5, 1974 | October 7, 1975 | Giannuzzi | - | Alphanumeric character display scheme for programmable electronic calculators | Keystroke programmable calculator utilizes LED next to each key during program review to identify key/function instead of a 2-digit row-column key code |
| 3920979 | Jack S. Kilby | October 19, 1973 | November 18, 1975 | Kilby | - | Electronic check writer | Checkbook calculator with printer |
| 3939452 | Olivetti | July 11, 1973 | February 17, 1976 | Faggian | - | Desk-top electronic computer with MOS circuit logic | Multi-chip MOS calculator system |
| 3940758 | (none) | September 20, 1974 | February 24, 1976 | Margolin | - | Expandable keyboard for electronic pocket calculators and the like | - |
| 3941989 | MOS Technology, Inc. | December 13, 1974 | March 2, 1976 | McLaughlin | - | Reducing power consumption in calculators | Reducing clock rate to reduce power consumption |
| 3947976 | Eric F. Burtis | March 10, 1975 | April 6, 1976 | Hafel | - | Mathematical problem and number generating system | Arithmetic quiz calculator |
| 3950654 | ami | November 14, 1974 | April 13, 1976 | Broedner | - | Power-on initializing circuit for a calculator system | - |
| 3955355 | Optel Corp. | March 27, 1974 | May 11, 1976 | Luce | calculator watch | Electronic calculator watch structures | Uses Texas Instruments TMS0100 |
| 3961159 | (none) | June 5, 1975 | June 1, 1976 | Hursey | - | Light shield/support device | Glare shield; may be flipped and used as a calculator stand |
| 3963906 | Kabushiki Kaisha Suwa Seikosha | November 16, 1971 | June 15, 1976 | Yamamura | - | Compact electronic calculator | Magnetic reed switches activated by magnetic stylus for a keyboard |
| 3967084 | KB-Denver, Inc. | May 12, 1975 | June 29, 1976 | Pounds | - | Keyboard switch assemblies having two foot support legs on dome-shaped contact member | Calculator keyboard snap-domes |
| 3974575 | (none) | June 24, 1974 | August 17, 1976 | Duncan | - | Teaching machine | Calculator chip (TMS1802, MK5020, MK5021, Rockwell 15330) based math drill device reading answers to problems from punched cards |
| 3978453 | Olivetti | April 24, 1973 | August 31, 1976 | Garziera | - | Input keyboard apparatus for an electronic computer | Keyboard matrix scanning circuit |
| 3983380 | McDonnell Douglas Corp. | August 11, 1975 | September 28, 1976 | Sharif | - | Auxiliary memory unit for use with an electronic display calculator | Almost “tapeless” adding machine review of entries |
| 3990053 | IBM | October 15, 1973 | November 2, 1976 | Evans | - | Stored program selector for electronic calculator | Rotary switch to select preprogrammed functions |
| 4000565 | IBM | May 5, 1975 | January 4, 1977 | Overby | - | Digital audio output device | Uses National Semiconductor MM5736 calculator chip; for visually impaired users |
| 4001566 | Pico Electronics Ltd. | March 19, 1971 | January 4, 1977 | Stevenson | - | Floating point calculator with RAM shift register | - |
| 4002892 | (none) | September 15, 1973 | January 11, 1977 | Zielinski | - | Portable calculator | Low profile LED calculator construction technique with removable rechargeable battery pack |
| 4014016 | Ball Brothers Research Corp. | November 29, 1974 | March 22, 1977 | Sherritt | - | Audio indicating system | Uses National Semiconductor MM5738 calculator chip |
| 4016411 | Jardine Industries, Inc. | January 29, 1976 | April 5, 1977 | Genin | - | Mini electronic calculator with blackboard display format | - |
| 4020527 | (none) | January 2, 1976 | May 3, 1977 | O'Neill | - | Grip for a hand held portable device | Sleeve for one or more fingers attached to calculator to prevent dropping |
| 4032753 | (none) | April 19, 1976 | June 28, 1977 | Lieberman | - | Programming apparatus | Mechanical button pusher |
| 4037200 | (none) | October 28, 1975 | July 19, 1977 | Cranmer | - | Braille display switching matrix and circuit utilizing the same | Braille calculator utilizing Cal-Tex CT5005 chip |
| 4040048 | (none) | March 10, 1975 | August 2, 1977 | Lien | - | Display of mathematical equations | Display of mathematical equations in arithmetic quiz calculator |
| 4041295 | Kabushiki Kaisha Suwa Seikosha | November 7, 1973 | August 9, 1977 | Ido | - | Electronic timepiece calculator | Shifted function keys reduce keyboard size on calculator watch |
| 4042439 | KB-Denver, Inc. | May 12, 1975 | August 15, 1977 | Pounds | - | Method of making keyboard assemblies | Calculator keyboard snap-domes |
| 4044980 | Cummins Enterprises | April 26, 1976 | August 30, 1977 | Cummins | - | Collapsible desktop stand for portable electronic calulator | Calculator stand; millions of these were sold |
| 4047010 | Centre Electronique Horloger S.A. | September 4, 1974 | September 6, 1977 | Perotto | calculator watch | Multi-function electronic watch | Calculator watch with stroked data entry; uses Texas Instruments TMS0100 |
| 4051608 | (none) | June 24, 1974 | October 4, 1977 | Duncan | - | Teaching machine | Calculator chip (TMS1802, MK5020, MK5021, Rockwell 15330) based math drill device reading answers to problems from punched cards |
| 4051942 | Alps Electric Co,. Ltd. | October 11, 1975 | October 4, 1977 | Suzuki | - | Printing apparatus | Two print wheels: numbers, symbols - very common printer mechanism |
| 4056700 | Western Digital Corp. | January 19, 1976 | November 1, 1977 | Stannek | - | Keyboard assembly momentary contact push button switch with tactile action | - |
| 4064399 | NEC | April 3, 1975 | December 20, 1977 | Muranaka | - | Electronic calculator having keyboard for entering data | Keyboard circuit to minimize interconnections between keyboard and chip |
| 4069659 | (none) | January 19, 1976 | January 24, 1978 | Harris | - | Electronic switch activated by current flow through the human body | Calculator watch with touch keyboard; uses MM5738 |
| 4071065 | (none) | December 16, 1976 | January 31, 1978 | Halbich | - | One piece container particularly adapted for calculator | Plastic calculator carrying case |
| 4078420 | Time Computer, Inc. | March 10, 1977 | March 14, 1978 | Reese | - | Digital watch analyzer | Digital watch test fixture has a built-in calculator |
| 4085306 | KB-Denver, Inc. | June 9, 1977 | April 18, 1978 | Dunlap | - | Keyboard switch assemblies | Calculator keyboard snap-dome |
| 4086654 | Kabushiki Kaisha Suwa Seikosha | November 7, 1974 | April 25, 1978 | Ido | - | Electronic timepiece calculator | Shifted (via SPDT switch) function keys to reduce keyboard size on calculator watch |
| 4087861 | Shinshu Seiki Kabushiki Kaisha and Kabushiki Kaisha Suwa Seikosha | December 10, 1975 | May 2, 1978 | Futagawa | - | Calculator | LCD calculator utilizing display lines as part of keyboard matrix |
| 4089124 | Eric F. Burtis | December 22, 1976 | May 16, 1978 | Burtis | - | Arithmetic training apparatus | Arithmetic quiz calculator that indicates an error as soon as first wrong digit for answer entered |
| 4091446 | Olivetti | January 24, 1975 | May 23, 1978 | Demonte | - | Desk top electronic computer with a removably mounted ROM | Calculator with removable ROM modules |
| 4093992 | Kabushiki Kaisha Suwa Seikosha | November 7, 1975 | June 6, 1978 | Kawamura | - | Electronic wristwatch | - |
| 4095217 | (none) | March 7, 1977 | June 13, 1978 | Tani | - | Combined liquid crystal display and photovoltaic converter | - |
| 4096577 | (none) | March 3, 1975 | June 20, 1978 | Ferber | - | Thin flexible electronic calculator | Uses National Semiconductor MM5736 |
| 4101963 | Time Computer, Inc. | May 25, 1977 | July 18, 1978 | Reese | calculator watch | Wristwatch with interface chip | Interface chip drives display for watch chip or calculator chip |
| 4103289 | (none) | April 27, 1976 | July 25, 1978 | Kolber | - | Calculator theft prevention device | PIN entry |
| 4113212 | (none) | June 8, 1977 | September 12, 1978 | Coriden | - | Collapsible electronic calculator stand | Calculator stand that is stuck to back of calculator |
| 4114026 | Olivetti | September 15, 1975 | September 12, 1978 | Fiorenza | - | Electronic desk-top accounting machine and calculator | Mechanical drum for programs |
| 4119839 | W & G Instruments, Inc. | November 30, 1976 | October 10, 1978 | Beckmann | - | Keyboard mask for general-purpose calculator | Keyboard overlay allows access to certain keys and blocks other keys; illustrated with HP-9825 |
| 4120039 | (none) | June 25, 1976 | October 10, 1978 | Ficher | calculator watch | Electronic digital watch combined with a computer | Calculator watch with hinged keyboard |
| 4120040 | Tokyo Shibaura Electric Co. | March 14, 1975 | October 10, 1978 | Aihara | - | Electronic calculator | Only four keys |
| 4120044 | RCA Corp. | September 16, 1976 | October 10, 1978 | Harayda | - | Data encoding keyboard | Encoded rotary thumbwheel pushbutton switch |
| 4139864 | (none) | January 14, 1976 | February 13, 1979 | Schulman | - | Security system for a solid state device | PIN entry |
| 4149257 | Citizen Watch Co. Ltd. | June 21, 1976 | April 10, 1979 | Nakagiri | - | Alarm watch equipped with electronic calculator | - |
| 4154007 | (none) | September 21, 1977 | May 15, 1979 | Judd | - | Demonstration calculator for classroom use and the like | Overhead projector calculator |
| 4158007 | (none) | September 21, 1977 | May 15, 1979 | Judd | - | Demonstration calculator for classroom use and the like | Overhead projector calculator |
| 4165554 | (none) | June 12, 1978 | August 28, 1979 | Faget | - | Hand-held portable calculator assembly | Protective case/cover |
| 4177501 | Harris Corp. | November 15, 1977 | December 4, 1979 | Karlin | - | Illuminated keyboard | - |
| 4186385 | Kabushiki Kaisha Suwa Seikosha | June 4, 1976 | January 29, 1980 | Nagashima | - | Electronic apparatus push button keyboard assembly | Keyboard matrix scanning circuit |
| 4195210 | KB-Denver, Inc. | February 27, 1979 | March 25, 1980 | Pounds | - | Switching assemblies | Non-spherical snap dome for calculator keyboard |
| 4202038 | (none) | August 10, 1977 | May 6, 1980 | Petersson | - | Method of effecting one of several different circuit connections | Reduced number of keys by assigning multiple functions to a key; disclosed embodiment uses TI-30 chip (TMC0981). |
| 4238806 | Olivetti | April 14, 1978 | December 9, 1980 | Bovio | - | Dot matrix printing device | Thermal print head designed to leave a blank area between first 14 and last 2 character positions |
| 4259568 | Henning Dynesen | October 12, 1979 | March 31, 1981 | Dynesen | - | Combined casing and operational support for a pocket calculator | Cover folds to form stand for calculator |
| 4262337 | General Motors Corp. | September 3, 1974 | April 14, 1981 | Jones | - | Portable calculator incorporating an anti-theft feature | Number sequence or calculation result required to enable display on calculator; apparently prototyped with Heathkit IC-2009 |
| 4264962 | Beam Engineering Kabushiki Kaisha | February 7, 1978 | April 28, 1981 | Kodaira | - | Small-sized electronic calculator | Solar powered calculator with cells on folding cover |
| 4268913 | Citizen Watch Co. Ltd. | May 18, 1976 | May 19, 1981 | Nakagiri | - | Electronic calculator watch | - |
| 4290708 | (none) | August 7, 1978 | September 22, 1981 | Siwula | - | Attachable microprocessors | Calculator housing that can be screwed, bolted, or clipped to other objects |
| 4320838 | BCG, Ltd. | January 7, 1980 | March 23, 1982 | Braver | - | Calculator tray apparatus | Calculator incorporated into writing tray |
| 4323979 | Litton Business Systems, Inc. | August 20, 1979 | April 6, 1982 | Johnston | - | Cartridge and bezel assembly for a calculator | Plug-in ROM cartridge like a video game cartridge |
| 4333155 | Litton Business Systems, Inc. | May 18, 1979 | June 1, 1982 | Johnston | - | Calculator having a modular keyboard | User replaceable key block (similar to HP-9805 key block) |
| 4375017 | RCA Corp. | December 6, 1976 | February 22, 1983 | Smith | - | Calculator type keyboard including printed circuit board contacts and method of forming | - |
| 4409666 | NEC | September 5, 1978 | October 11, 1983 | Nishiguchi | - | Electronic desk-top calculator with indication function of stored data range | Range checking |
| 4427314 | Epson | November 11, 1980 | January 24, 1984 | Fujiwara | - | Speed controlled printer | Thumbwheel provides printer mechanism energy, see 4433925 |
| 4433925 | Epson | November 10, 1981 | February 28, 1984 | Fujiwara | - | Manually-operated dot printer for pocket sized calculators | Thumbwheel provides printer mechanism energy, see 4427314 |
| 4551716 | Tokyo Shibaura Denki Kabushiki | June 30, 1981 | November 5, 1985 | Saito | - | Display control for electronic calculator | Different circuit for LCD calculator utilizing display lines as rows for the keyboard matrix |
| 4552464 | (none) | July 17, 1984 | November 12, 1985 | Rogers | - | Analogue dial calculator/wrist watch | - |
| 4587519 | Tokyo Shibaura Denki Kabushiki | July 15, 1981 | May 6, 1986 | Munetsugu | - | Input device | Different circuit for LCD calculator utilizing display lines as rows for the keyboard matrix |
| 4631700 | Laitram Corp. | January 21, 1983 | December 23, 1986 | Lapeyre | - | Magnetically coded software for multi-purpose computer | Keyboard overlay contains magnetic or optical stripe around edges for programs to be read by handheld calculator/computer |
| 4635219 | (none) | September 28, 1983 | January 6, 1987 | Howard | - | Printing calculator | Calculator prints when moved over a special pad of paper |
| 4680455 | Aurora Mechatronecs Corp. | March 31, 1986 | July 14, 1987 | Kuo | - | Method of manipulating a calculator and device used therewith | Scientific calculator with keyboard overlays providing instructions and exposing relevant keys |
| 4686643 | (none) | September 16, 1981 | August 11, 1987 | Ishiwata | - | Electronic equipment selectively storing a frequently used conversion function | Metric converter saves last conversion constant for shortcut reuse |
| 4751664 | Durratec Corp. | March 20, 1986 | June 14, 1988 | Holm | - | Enclosure device with magnetically attached calculator | Checkbook cover with magnetic flap to attach calculator |
| 4768648 | (none) | September 13, 1985 | September 6, 1988 | Glass | - | Calculator money clip | - |
| 4836786 | Joseph Leeb Enterprises, Inc. | August 7, 1987 | June 6, 1989 | Wong | - | Demonstration calculator | Overhead projector calculator |
| 4882685 | (none) | August 25, 1986 | November 21, 1989 | van der Lely | - | Voice activated compact electronic calculator | - |
| 5035502 | (none) | August 28, 1989 | July 30, 1991 | Stokes | - | Transparent calculator for overhead projection | Non-graphing transparent overhead calculator |
| 5093760 | (none) | January 11, 1991 | March 3, 1992 | Bedol | - | Calculator having a thin resilient clip disposed about the outer periphery | Giant plastic paperclip-like calculator case |
| 5209592 | (none) | December 9, 1991 | May 11, 1993 | Bedol | - | Notebook insert with calculator and holepunch | - |
| 5243550 | (none) | March 27, 1992 | September 7, 1993 | Cannizzaro | - | Multi-column printing calculator | Multi-column printing for deposit slips, invoices, etc. |
| 5404186 | (none) | August 28, 1989 | April 4, 1995 | Stokes | - | Transparent calculator for overhead projection | Non-graphing transparent overhead calculator |
| 5515125 | (none) | November 14, 1994 | May 7, 1996 | Gerver | - | Storage cart for instructional devices | Storage cart is cage for overhead projector and remote LCD view screen to prevent theft |
| 5515304 | (none) | July 19, 1994 | May 7, 1996 | Ishii | - | Portable calculator for an array calculation | Array/tabular calculator |
| 5623433 | (none) | January 11, 1993 | April 22, 1997 | Redin | X-Number | Extended numerical keyboard with structured data-entry capability | - |
| 5638308 | (none) | December 22, 1994 | June 10, 1997 | Stokes | - | Calculator with keys which can selectively be disabled | Disable selected keys under software control |
| 6178085 | CCL Products Enterprises, Inc. | April 27, 1998 | January 23, 2001 | Leung | many different models | Calculator lid mechanism | Flip-top display cover |
| 6557018 | (none) | January 7, 2000 | April 29, 2003 | Shibasaki | - | Desk calculator capable of easy checking and trustworthy calculation | History buffer allows review and correction of calculations |
| 6606762 | Myron Corp. | March 4, 2002 | August 19, 2003 | Levine | - | Hinge for a rotatably connected cover | Different spring mechanism for flip-top calculator display cover |
| 6754683 | Samsung | March 5, 1999 | June 22, 2004 | Park | - | Method of implementing an electronic calculator function in a portable terminal | Calculator function for cell phone or similar device |
| 6820800 | (none) | August 1, 2001 | November 23, 2004 | Samson | - | Electronic calculator | Educational calculator requiring input of estimated result by student |
Last updated November 5, 2006
