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 |
| 3388385 | HP | May 19, 1966 | June 11, 1968 | Lukes | - | Nondestructive round-off display circuit | - |
| 3566160 | HP | June 23, 1966 | February 23, 1971 | Osborne | pre-HP9100 prototype | Simplified race-preventing flip-flop having a selectable noise immunity threshold | - |
| 3576983 | HP | October 2, 1968 | May 4, 1971 | Cochran | - | Digital calculator system for computing square roots | - |
| 3623156 | HP | June 23, 1966 | November 23, 1971 | Osborne | pre-HP9100 prototype | Calculator employing multiple registers and feedback paths for flexible subroutine control | - |
| 3668461 | HP | June 23, 1966 | June 6, 1972 | Osborne | pre-HP9100 prototype | Output display for use with a calculator | Stroked vector scheme for displaying numbers on a CRT |
| 3675213 | HP | October 14, 1970 | July 4, 1972 | Spangler | HP9100? | Stored data recall means for an electronic calculator | - |
| 3678466 | HP | October 14, 1970 | July 18, 1972 | Spangler | - | Electronic calculator | Provides for a switch selectable secondary display register for program step and instruction data, leaving data in primary numeric display register undisturbed |
| 3769621 | HP | May 26, 1969 | October 30, 1973 | Osborne | pre-HP9100 prototype | Calculator with provision for automatically interposing memory access cycles between otherwise regularly recurring logic cycles | See 3566160 and 3623156 |
| 3781820 | HP | May 30, 1972 | December 25, 1973 | Cochran | HP35 | Portable electronic calulator | - |
| 3839630 | HP | December 27, 1971 | October 1, 1974 | Olander | HP9820 | Programmable calculator employing algebraic language | - |
| 3855461 | HP | August 30, 1973 | December 17, 1974 | Stockwell | HP65 | Calculator with key code association and display features | Keystroke programmable calculator associates key with two digit row-column number, and numberic keys with the digit |
| 3859635 | HP | June 15, 1971 | January 7, 1975 | Watson | HP9810 | Programmable calculator | - |
| 3863060 | HP | October 30, 1972 | January 28, 1975 | Rode | HP80 | General purpose calculator with capability for performing interdisciplinary business calculations | Financial calculator; includes source code |
| 3892958 | HP | January 11, 1974 | July 1, 1975 | Tung | HP65 | Inverse/complementary function prefix key | Inverse and complementary function keys, allowing up to 4 functions to be assigned to a key |
| 3916135 | HP | July 3, 1974 | October 28, 1975 | Holden | classic series | Keyboard type switch with rocker type key actuator | - |
| 3934695 | HP | September 23, 1974 | January 27, 1976 | Kovalich | HP19C/HP10 | Method and apparatus for enhancing and maintaining character quality in thermal printers | - |
| 3941953 | HP | August 23, 1971 | March 2, 1976 | Mission | HP35 | Keyboard having switches with tactile feedback | - |
| 3946218 | HP | October 30, 1972 | March 23, 1976 | Rode | HP80 | General purpose calculator with capability for performing yield-to-maturity of a bond calculation | - |
| 3955074 | HP | October 30, 1972 | May 4, 1976 | Rode | HP80 | General purpose calculator having keys with more than one function assigned thereto | Dual-function keys, second function accessed using a shift key |
| 3971925 | HP | December 26, 1972 | July 27, 1976 | Wenninger | HP9805 | Adaptable programmed calculator having provision for plug-in keyboard and memory modules | - |
| 3973110 | HP | July 26, 1974 | August 3, 1976 | Rode | HP01? | Circulating shift register time-keeping circuit | - |
| 3987290 | HP | May 19, 1975 | October 19, 1976 | Dickinson | HP25 | Calculator apparatus for displaying data in engineering notation | - |
| 3996562 | HP | June 26, 1964 | December 7, 1976 | Reach | Mathatron | Programmable electronic calculator for evaluating mathematical problems | - |
| 4001569 | HP | May 29, 1973 | January 4, 1977 | Dickinson | HP45 | General purpose calculator having selective data storage, data conversion and time-keeping capabilities | Metric and degrees-minutes-seconds conversions; includes source code |
| 4009379 | HP | December 16, 1974 | February 22, 1977 | Musch | HP65 | Portable programmable calculator displaying absolute line number addresses and key codes and automatically altering display formats | Keystroke programmable calculator displaying key-codes in row-column format along with line number; includes source code |
| 4010456 | HP | March 10, 1975 | March 1, 1977 | Erni | HP21 | Low battery voltage indicator for a portable digital electronic instrument | - |
| 4012725 | HP | July 7, 1972 | March 15, 1977 | Spangler | HP9830 | Programmable calculator | - |
| 4028538 | HP | December 27, 1971 | June 7, 1977 | Olander | HP9820 | Programmable calculator employing algebraic language | - |
| 4035627 | HP | May 29, 1973 | July 12, 1977 | Dickinson | HP45 | Scientific calculator | (Not HP-55!) stopwatch function. |
| 4037092 | HP | November 26, 1973 | July 19, 1977 | Osborne | HP67/97 | Calculator having preprogrammed user-definable functions | User programmable function keys which default to predefined functions upon powerup |
| 4047012 | HP | May 29, 1973 | September 6, 1977 | Dickinson | HP45 | General purpose calculator having factorial capability | Factorial function key |
| 4055757 | HP | August 27, 1976 | October 25, 1977 | Tillman | HP22 | Calculator apparatus with annuity switch for performing begin-and end-period annuity calculations | Financial calculator with annuity begin/end period switch |
| 4059213 | HP | October 17, 1974 | November 22, 1977 | Toomay | ? | Clutchless paper advance mechanism | - |
| 4059750 | HP | May 29, 1973 | November 22, 1977 | Dickinson | HP55 | General purpose calculator having selective data storage, data conversion and time-keeping capabilities | Last-X function-key/register |
| 4063221 | HP | June 15, 1971 | December 13, 1977 | Watson | HP9810 | Programmable calculator | - |
| 4070680 | HP | August 20, 1976 | January 24, 1978 | Shelley | - | Thermal printer-plotter system for multi-directional printing and plotting | - |
| 4075679 | HP | December 8, 1975 | February 21, 1978 | Christopher | HP9825 | Programmable calculator | - |
| 4078257 | HP | August 23, 1976 | March 7, 1978 | Bagley | ? | Calculator apparatus with electronically alterable key symbols | - |
| 4089059 | HP | July 21, 1975 | May 9, 1978 | Miller | HP9815 | Programmable calculator employing a read-write memory having a movable boundary between program and data storage sections thereof | - |
| 4091270 | HP | July 19, 1976 | May 23, 1978 | Musch | ? | Electronic calculator with optical input means | - |
| 4099246 | HP | December 17, 1973 | July 4, 1978 | Osborne | HP65 | Calculator having merged key codes | Partially merged keystrokes, 6-bit instruction word; includes source code |
| 4106677 | HP | August 19, 1976 | August 15, 1978 | Helmso | ? | Wrist wearable electronic device with an engagedly stored selected tool | - |
| 4109315 | HP | August 30, 1976 | August 22, 1978 | Pan | HP01 | Wristwatch calculator with selectively scanned keyboard | Power saving keyboard scanning technique |
| 4126898 | HP | July 7, 1972 | November 21, 1978 | Spangler | HP9830 | Programmable calculator including terminal control means | - |
| 4127897 | HP | July 7, 1972 | November 28, 1978 | Spangler | HP9830 | Programmable calculator having extended input/output capability | - |
| 4145742 | HP | December 27, 1971 | March 20, 1979 | Olander | HP9820 | Programmable calculator including user-definable keys | - |
| 4145752 | HP | December 27, 1971 | March 20, 1979 | Olander | HP9820 | Programmable calculator including separate line numbering means for user-definable functions | - |
| 4152769 | HP | December 27, 1971 | May 1, 1979 | Olander | HP9820 | Programmable calculator including means for permitting data entry during program execution | - |
| 4152770 | HP | December 27, 1971 | May 1, 1979 | Olander | HP9820 | Programmable calculator including means for programmably controlling magnetic storage units | - |
| 4152771 | HP | December 27, 1971 | May 1, 1979 | Olander | HP9820 | Programmable calculator including display means for signaling the user to indicate the exhaustion of a printer paper supply | - |
| 4152773 | HP | December 27, 1971 | May 1, 1979 | Olander | HP9820 | Programmable calculator including means for establishing a priority for executing algebraic operations | - |
| 4152774 | HP | December 27, 1971 | May 1, 1979 | Olander | HP9820 | Programmable calculator including keyboard function means for raising the number ten to any designated power | - |
| 4156282 | HP | December 27, 1971 | May 22, 1979 | Olander | HP9820 | Programmable calculator including relational operator means | - |
| 4156285 | HP | December 27, 1971 | May 22, 1979 | Olander | HP9820 | Programmable calculator including keyboard functions whose argument may be a numeric constant, a storage register, or an arithmetic expression | - |
| 4156917 | HP | December 27, 1971 | May 29, 1979 | Olander | HP9820 | Programmable calculator including separate user program and data memory areas | - |
| 4156918 | HP | December 27, 1971 | May 29, 1979 | Olander | HP9820 | Programmable calculator including means for performing computed jumps during program execution | - |
| 4156921 | HP | December 26, 1972 | May 29, 1979 | Wenninger | HP9805 | Adaptable programmed calculator including automatic decimal point positioning | - |
| 4158228 | HP | December 27, 1971 | June 12, 1979 | Olander | HP9820 | Programmable calculator including alphanumeric error display means | - |
| 4158231 | HP | December 27, 1971 | June 12, 1979 | Olander | HP9820 | Programmable calculator including program listing means | - |
| 4158233 | HP | December 27, 1971 | June 12, 1979 | Olander | HP9820 | Programmable calculator including means for performing implied multiply operations | - |
| 4158285 | HP | February 9, 1976 | June 19, 1979 | Heinsen | HP01 | Interactive wristwatch calculator | - |
| 4159525 | HP | December 27, 1971 | June 26, 1979 | Olander | HP9820 | Programmable calculator employing computed memory addresses | - |
| 4161031 | HP | December 27, 1971 | July 10, 1979 | Olander | HP9820 | Programmable calculator including boolean flag variable means | - |
| 4162532 | HP | December 27, 1971 | July 24, 1979 | Olander | HP9820 | Programmable calculator including data format display control means | - |
| 4164019 | HP | December 27, 1971 | August 7, 1979 | Olander | HP9820 | Programmable calculator including alphanumeric display means | - |
| 4164039 | HP | December 27, 1971 | August 7, 1979 | Olander | HP9820 | Programmable calculator including a key for performing either a subtraction or a unary minus function | - |
| 4177518 | HP | December 27, 1971 | December 4, 1979 | Olander | HP9820 | Programmable calculator including scrolling alphanumeric display means | - |
| 4177520 | HP | August 14, 1975 | December 4, 1979 | Meff | HP65 | Calculator apparatus having a single-step key for displaying and executing program steps and displaying the result | - |
| 4178633 | HP | December 27, 1971 | December 11, 1979 | Olander | HP9820 | Programmable calculator including multifunction keys | - |
| 4180854 | HP | September 29, 1977 | December 25, 1979 | Walden | HP9845 | Programmable calculator having string variable editing capability | - |
| 4181965 | HP | December 27, 1971 | January 1, 1980 | Olander | HP9820 | Programmable calculator including program trace means | - |
| 4181966 | HP | December 26, 1972 | January 1, 1980 | Wenninger | HP9805 | Adaptable programmed calculator including a percent keyboard operator | - |
| 4187547 | HP | December 27, 1971 | February 5, 1980 | Olander | HP9820 | Programmable calculator including means for controllably introducing blank lines on a printed record during program execution | - |
| 4197586 | HP | April 24, 1978 | April 8, 1980 | Nidiffer | Spice | Electronic calculator assembly | - |
| 4198684 | HP | June 26, 1964 | April 15, 1980 | Reach | Mathatron | Electronic calculator with keyboard-controlled unary function capability | - |
| 4203152 | HP | June 15, 1971 | May 13, 1980 | Watson | HP9810 | Programmable calculator including key-log printing means | - |
| 4232382 | HP | May 26, 1977 | November 4, 1980 | Heinsen | HP01 | Incrementing signal hold circuit for a clock/calculator | - |
| 4281390 | HP | December 27, 1971 | June 28, 1981 | Olander | HP9820 | Programmable calculator including means for performing computed and uncomputed relative branching during program execution | - |
| 4291385 | HP | December 17, 1973 | September 22, 1981 | Osborne | HP65 | Calculator having merged key codes | Partially merged keystrokes, 6-bit instruction word; includes source code |
| 4300844 | HP | August 22, 1979 | November 17, 1981 | Keil | - | Moving head printer mechanism | - |
| 4309761 | HP | June 26, 1964 | January 5, 1982 | Reach | Mathatron | Calculator for evaluating numerical answers to problems | - |
| 4322816 | HP | July 7, 1972 | March 30, 1982 | Spangler | HP9830 | Programmable calculator having structure for controlling an x-y plotter | - |
| 4327366 | HP | January 24, 1980 | April 27, 1982 | Schafter | - | Flexible low friction platen cover for recording apparatus | Soft platen for thermal printer |
| 4330839 | HP | July 21, 1973 | May 18, 1982 | Miller | HP9815 | Programmable calculator including means for automatically processing information stored on a magnetic record member | - |
| 4366553 | HP | July 7, 1972 | December 28, 1982 | Spangler | HP9830 | Electronic computing apparatus employing basic language | - |
| 4381554 | HP | June 26, 1964 | April 26, 1983 | Reach | Mathatron | Calculator for storing source data and evaluating numerical answers to problems | - |
| 4384328 | HP | June 15, 1971 | May 17, 1983 | Watson | HP9810 | Programmable calculator including magnetic reading and recording means | - |
| 4412300 | HP | June 15, 1971 | October 25, 1983 | Watson | HP9810 | Programmable calculator including alphabetic output capability | - |
| 4430531 | HP | March 15, 1982 | February 7, 1984 | Wright | Voyager | Snap disc keyboard | - |
| 4437156 | HP | December 8, 1975 | March 13, 1984 | Christopher | HP9825 | Programmable calculator | - |
| 4455607 | HP | June 15, 1971 | June 19, 1984 | Watson | HP9810 | Programmable calculator having keys for performing angular measurement unit conversion | - |
| 4455618 | HP | September 29, 1977 | June 19, 1984 | Walden | HP9845 | Programmable calculator | - |
| 4456964 | HP | December 27, 1971 | June 26, 1984 | Olander | HP9820 | Calculator including means for displaying alphanumeric prompting messages to the operator | - |
| 4477134 | HP | August 14, 1981 | October 16, 1984 | Wright | HP71B | Electrostatic discharge protected integrated circuit module | - |
| 4480305 | HP | June 15, 1971 | October 30, 1984 | Watson | HP9810 | Programmable calculator including editing capability | - |
| 4546448 | HP | July 7, 1972 | October 8, 1985 | Spangler | HP9830 | Programmable calculator including program variable initialization means and definition means array | - |
| 4566072 | HP | July 21, 1975 | January 21, 1986 | Mortensen | HP9815 | Programmable calculator including means for digitizing the position of an X-Y plotter pen | - |
| 4611307 | HP | June 26, 1964 | September 9, 1986 | Reach | Mathatron | Function analyzing | - |
| 4615015 | HP | December 27, 1971 | September 30, 1986 | Olander | HP9820 | Self-contained electronic computer including means for immediately executing or storing alphanumeric statements entered into the computer | - |
| 4698784 | HP | January 6, 1984 | October 6, 1987 | Abell | HP71B | Syntactic device for chain calculations | - |
| 4774493 | HP | May 15, 1986 | September 27, 1988 | Rabinowitz | - | Method and apparatus for transferring information into electronic systems | Method of transferring test program into a chip modulated over power supply pins, thus avoiding a separate test pins; shows calculator architecture as example |
| 4821118 | HP | December 24, 1986 | April 11, 1989 | Wickes | HP28C | Method and apparatus for computation stack recovery in a calculator | - |
| 4821228 | HP | December 24, 1986 | April 11, 1989 | Wickes | HP28C | Method and apparatus for computation stack recovery in a calculator | - |
| 4825395 | HP | May 29, 1986 | April 25, 1989 | Kinser | HP28C | Apparatus with torsionally stressed conductors routed through a hollow articulated hinge | - |
| 4834504 | HP | October 9, 1987 | May 30, 1989 | Garner | - | Lcd compensation for non-optimum voltage conditions | - |
| 4843590 | HP | May 29, 1986 | June 27, 1989 | Wechsler | HP18C | History stack | - |
| 4845652 | HP | May 29, 1986 | July 4, 1989 | Bunsen | HP18C | Generic equation solver interface for solving mathematical equations | - |
| 4852057 | HP | October 27, 1986 | July 25, 1989 | Patton | HP28C | Algebraic expression manipulation method and implementation for an electronic data processing apparatus | - |
| 4868745 | HP | May 30, 1986 | September 18, 1989 | Patton | HP28C? | Data processing system and method for the direct and indirect execution of uniformly structured object types | - |
| 4878293 | HP | May 29, 1986 | November 7, 1989 | Kinser | HP28C | Method of interconnecting assemblies using torsionly stressed conductors routed through a hollow articulated hinge | - |
| 4885430 | HP | May 29, 1986 | December 5, 1989 | Kinser | HP28C | Flexible printed circuit assembly with torsionly rotated conductors | - |
| 4885714 | HP | October 27, 1986 | December 5, 1989 | Eisenstein | HP28C | Calculator having a user-accessible object stack for the uniform application of mathematical functions and logical operations to a multiplicity of object types | - |
| 5007008 | HP | August 17, 1990 | April 9, 1991 | Beers | HP48S | Method and apparatus for selecting key action | - |
| 5020012 | HP | December 15, 1988 | May 28, 1991 | Stockberger | HP32S | Method and apparatus for matching menu labels with keys | - |
| 5025403 | HP | October 30, 1989 | June 18, 1991 | Stephens | HP32SII | Fraction entry and display | - |
| 5060990 | HP | February 8, 1991 | October 29, 1991 | Smith | HP48S | Multi-stage door snap | - |
| 5065356 | HP | December 19, 1988 | November 12, 1991 | Puckette | HP42S | Shared use of keyboard and memory lines | - |
| 5067102 | HP | January 31, 1990 | November 19, 1991 | Eisenstein | HP48S | Method and apparatus for displaying and editing mathematical expressions in textbook format | - |
| 5075792 | HP | March 20, 1989 | December 24, 1991 | Brown | HP48S?/HP95LX | Low power optical transceiver for portable computing devices | (see 5,495,358 for HP95LX referenced as prior art) |
| 5089980 | HP | October 30, 1989 | February 18, 1992 | Bunsen | HP32SII | Double keystroke fraction entry and interface method | - |
| 5123102 | HP | December 19, 1988 | June 16, 1992 | Puckette | ? | Method and apparatus for suspending computation due to detection of electrostatic discharge | - |
| 5128887 | HP | January 31, 1991 | July 7, 1992 | Smith | - | Numeric accuracy indicator for rounded numeric value display method | Shows > or < if displayed fraction or decimal value different than internal falue |
| 5175700 | HP | January 25, 1991 | December 29, 1992 | Vogel | HP48S | Method and apparatus for solving multiple equations | - |
| 5216627 | HP | January 25, 1991 | June 1, 1993 | McClellan | HP48S | Method and apparatus for computing with terms having units | Objects containing scalar and units parts |
| 5260886 | HP | July 26, 1991 | November 9, 1993 | Bunsen | ??? | Default denominator for fraction entry and display | - |
| 5530234 | HP | December 23, 1994 | June 25, 1996 | Loh | - | Hand held calculator having a retractable cover | (not sold, probably HP38G alternative design) |
| 5594673 | HP | February 5, 1993 | January 14, 1997 | Coffin | HP48G? | Method and apparatus for displaying menu options for selection with a minimum of key stroke | - |
| RE30743 | HP | August 20, 1976 | September 15, 1981 | Shelley | - | Thermal printer-plotter system for multi-directional printing and plotting | Reissue of 4070680 |
Last updated November 5, 2006
