# US 4,396,912 A · Method and means for point connecting with a differential integrator dot connector circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,396,912 A - Document ID: US4396912A - Status: Granted - Kind: A - Application number: 06/293,711 - Filed: 1981-08-17 - Granted: 1983-08-02 - Earliest claimed: 1981-08-17 - Assignees: Hewlett-Packard Company - Inventors: Michael A. Pozzi - Web page: https://patentgrep.com/patent/US4396912A ## CPC - G01R 13/20: Cathode-ray oscilloscopes - G09G 1/12: the deflection signals being produced by essentially analogue means - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A novel circuit employing a differential integrator having differential inputs V.sub.1 and V.sub.2 provides a substantially uniformly varying output voltage representative of a straight line for connecting two display points having voltage levels V.sub.1 and V.sub.2. This circuit is ideally used in the reconstruction of analog waveforms from digitally stored data for display on an oscilloscope. ## Claims ### Claim 1 An apparatus to display two points having voltage levels V.sub.1 and V.sub.2 interconnected by a substantially uniformly varying voltage representative of a straight line, comprising: current source means for providing an output current directly proportional to the difference of its input voltages, said current source means having first and second input ports for accepting said V.sub.1 and V.sub.2 volts, respectively; capacitance means coupled to said first current source means for providing in response to said output current said substantially uniformly varying voltage; and a video display having an amplitude input port coupled to said substantially uniformly varying voltage. ### Claim 2 An apparatus to connect two display points having voltage levels V.sub.1 and V.sub.2 with a substantially uniformly varying voltage representative of a straight line, comprising: current source means for providing an output current directly proportional to the difference of its input voltages, said current source means having first and second input ports for accepting said V.sub.1 and V.sub.2 volts, respectively; capacitance means coupled to said current source means for providing in response to said output current said substantially uniformly varying voltage; a sample-and-hold circuit having its input port coupled to said capacitance means and its output port coupled to said current source means for sampling a voltage level at said capacitance means and for providing said sampled voltage as said V.sub.1 to said first input port; and input amplifier means coupled to said second input port for providing said V.sub.2 to said current source means. ### Claim 3 (depends on 2) The apparatus as in claim 2 wherein said input amplifier means comprises a digital-to-analog converter means for converting digital data into a voltage output V.sub.2. ### Claim 4 (depends on 2, 3) The apparatus as in claim 2 or 3 further comprising a buffer amplifier coupled to said capacitance means for coupling externally said substantially uniformly varying voltage having V.sub.1 and V.sub.2 as end points. ### Claim 5 A method for displaying two points having voltage levels V.sub.1 and V.sub.2 interconnected by a substantially uniformly varying voltage representative of a straight line, comprising the steps of: applying said V.sub.1 to a first input port of a current source means for providing an output current directly proportional to the difference of its input voltages; applying said V.sub.2 to a second input port of said current source means; charging with said output current a capacitance means for providing in response to said output current said substantially uniformly varying voltage; and applying said substantially uniformly varying voltage to the amplitude input port of a video display. ### Claim 6 A method for connecting two display points having voltage levels V.sub.1 and V.sub.2 with a substantially uniformly varying voltage representative of a straight line, comprising the steps of: applying said V.sub.1 to a first input port of a current source means for providing an output current directly proportional to the difference of its input voltages; applying said V.sub.2 to a second input port of said current source means; charging with said output current a capacitance means for providing in response to said output current said substantially uniformly varying voltage; sampling said capacitance means at a select voltage level; coupling said sampled voltage to said first input port, said sampled voltage being said V.sub.1 ; amplifying an applied input; and coupling said amplified applied input to said second input port, said amplified input being said V.sub.2. ### Claim 7 (depends on 6) The method as in claim 6 wherein said step of amplifying comprises converting an applied digital input to an analog voltage and amplifying same. ### Claim 8 (depends on 6, 7) The method as in claim 6 or 7 further comprising the step of amplifying said substantially uniformly varying voltage to provide a buffered output signal.