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Archaic Legal Glossary & Citations

“Letters Patent”14th–20th Century
19th-C Meaning:

Open public letters from a monarch or government (literae patentes) granting monopoly rights.

Modern Engineering Decoded:Issued USPTO utility or design patent publication.
Historical note: Contrasted with 'letters close' (private sealed royal correspondence).
“In testimony whereof”19th Century
19th-C Meaning:

Formal concluding legal formula affirming under oath the execution of the instrument.

Modern Engineering Decoded:Inventor and witness digital/physical signatures.
Historical note: Required two witness attestations in 19th-century USPTO filing procedure.
“Aeroplane”Early 20th Century (Wright era)
19th-C Meaning:

A flat or cambered lifting aerofoil surface supported dynamically by air pressure.

Modern Engineering Decoded:Wing / Airfoil lifting surface (later evolved to mean the entire motorized aircraft).
Historical note: The Wrights used 'aeroplane' to denote the individual fabric-covered wings.
“Undulating Current”19th Century (Bell era)
19th-C Meaning:

An electric current whose magnitude varies continuously and periodically without interruption.

Modern Engineering Decoded:Continuous analog AC or audio-frequency electrical waveform.
Historical note: Bell's central legal weapon against telegraph companies who relied on pulsed DC make-and-break circuits.
“Subdivision of the Electric Light”1870s–1880s (Edison era)
19th-C Meaning:

The problem of operating numerous small domestic lamps off a single electrical generator.

Modern Engineering Decoded:Parallel circuit wiring of high-resistance incandescent electrical loads.
Historical note: Pundits claimed it was physically impossible until Edison increased filament resistance to 100 ohms.
“Optically Anisotropic Solution”1960s (Kwolek era)
19th-C Meaning:

A liquid solution that exhibits direction-dependent refractive indices due to molecular alignment.

Modern Engineering Decoded:Liquid crystalline nematic phase polymer dope.
Historical note: Technicians initially tried to throw out Kwolek's cloudy solution thinking it was contaminated.
“Unitary Body of Semiconductor Material”1950s–1960s (Noyce era)
19th-C Meaning:

A single continuous crystal structure of silicon or germanium.

Modern Engineering Decoded:Monolithic single-crystal silicon die / integrated circuit wafer.
Historical note: Differentiated Noyce's monolithic planar circuit from Jack Kilby's hybrid flying-wire prototype.
“Peculiar and Novel Construction”19th Century
19th-C Meaning:

A distinctive, patentable structural arrangement not found in prior art.

Modern Engineering Decoded:Novel and non-obvious mechanical embodiment under 35 U.S.C. § 103.
Historical note: Standard 19th-century legal terminology establishing novelty.

Museum Broadside & Archival Print Edition

Authentic archival layout formatted for framing, study, and high-resolution printing

Paper:
Theme:
The United States Patent & Trademark Archive

Historical Specification & Engineering Broadside

Curated, Verified & Restored by Classic Patents (classic-patents.com)
THREE-ELECTRODE CIRCUIT ELEMENT UTILIZING SEMICONDUCTIVE MATERIALSForward emitter injection and reverse collector capture in a semiconductor surface layer
US 2,524,035Class: Cl. 179-171
Inventor(s):John Bardeen, Walter H. Brattain
Origin / Location:Summit and Morristown, New Jersey
Grant & Filing:Filed June 17, 1948 · Granted October 3, 1950

I. Historical Context & Grant Summary

US 2,524,035 claims a three-electrode semiconductor circuit element in which a forward-biased emitter supplies carriers through an opposite-type surface layer and a reverse-biased collector receives a portion of the resulting current. The application was filed June 17, 1948 and the grant issued October 3, 1950.

II. Core Mechanism & Scientific Principles

The patent turns a surface-layer carrier current into a controllable high-impedance collector current. Its legal core is not simply any modern transistor: it specifies a body, opposite-type surface region, close emitter and collector contacts, and their stated bias and collection relationships.

Physical Operation:Forward emitter bias injects carriers into the surface layer; a nearby reverse-biased collector shapes an electric field and captures part of the spreading carrier current. In the three reported operating samples, a small emitter signal changed collector current through a high load impedance and produced the tabled voltage and power gains. Those sample measurements are not universal device constants.
Governing Formulation:
Carrier injection and collection:I_E = f(V_E + R_f I_C); I_C = I_C^0(V_C) + a I_E
Electric field across a barrier:E ≈ V/d

III. The Granted Legal Monopoly (Key Claims)

Claim 1 (Independent)Opposite-type surface layer

Claims the core three-terminal element: opposite-type surface layer, emitter and collector on that layer, and a base on the body. The collector is expressly positioned to collect current spreading from the emitter.

Claim 2 (Dependent)Same-composition surface layer

Narrows claim 1 to a surface layer made from the same chemical material as the block, so the distinction is conductivity behavior rather than a dissimilar deposited semiconductor.

Claim 3 (Dependent)Germanium supporting body

Narrows the basic element to germanium, the material used in the worked example, without importing all of the example's fabrication steps into claim 1. It does not require the separate N-type and P-type material assignments of the next claim.

IV. Mechanical Organ Breakdown

Supporting semiconductor bodyTerm: “semiconductive supporting body” → semiconductor substrate

The bulk material supports the surface layer and base contact.

Emitter and collector contactsTerm: “point contact” → localized metal-semiconductor contact

Close rectifying contacts create injection and collection regions.

Bias and external circuitsTerm: “” →

A low-impedance input drives the emitter while a higher-impedance collector circuit delivers output.

CLASSIC PATENTS DIGITAL ARCHIVE • PERMANENT EXHIBIT ID: us-2524035-bardeen-transistor
classic-patents.com/patents/us-2524035-bardeen-transistor
Original USPTO PDF
Classic Patents/US 2,524,035
Semiconductor Revolution (1950–1975)Solid-State Physics & Semiconductors

Bardeen and Brattain Point-Contact Transistor

US 2,524,035

Forward emitter injection and reverse collector capture in a semiconductor surface layer

Inventor(s)John Bardeen, Walter H. Brattain
Grant DateOctober 3, 1950
Filing DateJune 17, 1948
LocationSummit and Morristown, New Jersey
US 2,524,035 claims a three-electrode semiconductor circuit element in which a forward-biased emitter supplies carriers through an opposite-type surface layer and a reverse-biased collector receives a portion of the resulting current. The application was filed June 17, 1948 and the grant issued October 3, 1950.
USPTO PDF
Audio Engineering Breakdown~1 min listen

Listen to the narrated mechanical breakdown and civilizational context

Engineering Analysis & Physical Principles

How It Works: Step-by-Step Mechanical & Physical Breakdown

The patent turns a surface-layer carrier current into a controllable high-impedance collector current. Its legal core is not simply any modern transistor: it specifies a body, opposite-type surface region, close emitter and collector contacts, and their stated bias and collection relationships.
The Core Breakthrough Mechanism

Forward emitter bias injects carriers into the surface layer; a nearby reverse-biased collector shapes an electric field and captures part of the spreading carrier current. In the three reported operating samples, a small emitter signal changed collector current through a high load impedance and produced the tabled voltage and power gains. Those sample measurements are not universal device constants.

Interactive Real-Time Physical Simulation

Drag to rotate · Pinch to zoom · Shared controls update the displayed model
INITIALIZING THREE.JS WEBGL SIMULATION...
Source-Reported Point-Contact Amplifier Operating Samples.
Host-Model Telemetry/Computed Readout
Source-Reported Point-Contact Amplifier Operating Samples
Reported Voltage Gain
Source
62×[1]
Reported Power Gain
Source
80×[1]
Selected Contact Gap
Reader Scenario
50.8µm[L]
Claim 1 Contact Path
Reader Scenario
complete[1]
Reported Table I Sample1 sample
Preferred Contact Spacing2 mils
Claim 1 Contact Path1 on/off
Interval ghosts
α1.7 · [0.2, 3]
Fidelity / MMS residual
Power gain vs Bell Labs 1947 audio speech test
model18.5 dB
reference18.0 dB
residual0.5 dB
Coupled channels
emitter bias → collector amplified signal0 W
Dated scenarios

Detailed Component Architecture

1Supporting semiconductor body
The bulk material supports the surface layer and base contact.

The source distinguishes N- and P-type carrier populations and places the base at low resistance to the body; surface and bulk are separated by a high-resistance barrier where specified.

19th-C. Term: semiconductive supporting bodyModern: semiconductor substrate
2Emitter and collector contacts
Close rectifying contacts create injection and collection regions.

The emitter is forward-biased and the collector reverse-biased. The specification reports best results at a surface separation of 1 to 10 mils; the close contacts let current spread in the layer and enter the collector field before it crosses to the base.

19th-C. Term: point contactModern: localized metal-semiconductor contact
3Bias and external circuits
A low-impedance input drives the emitter while a higher-impedance collector circuit delivers output.

The patent identifies conventional, grounded-grid, grounded-plate, and feedback connections, but makes the carrier and polarity conditions—not a tube metaphor—the operating limitation.

Engineering Principles & Equations

Governing Equations & Engineering Principles

Authored explanation paired with its stated mathematical relation

Point-Contact Minority Hole Injection & Dynamic Current Amplification

Solid-State Semiconductor PhysicsClaim 1
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
The measures the change in induced by , producing massive by transferring current from a to a .
α\alpha
Current Gain Factor
Differential current transfer ratio (∂Ic/∂Ie≈1.5–3.0\partial I_c / \partial I_e \approx 1.5\text{--}3.0 in point-contact Ge)
Dimensionless gain ratio

In point-contact transistors, holes injected from the gold foil emitter create an electron-trapping space charge that pulls multiple electrons from the base into the collector, yielding alpha > 1.

Physical Principle & Engineering Insight

Bardeen and Brattain discovered that pressing two gold-leaf contacts onto a germanium crystal just 0.002 inches apart allowed holes injected by the emitter to control the reverse current of the collector, creating the world's first solid-state amplifier.

Historical Context: US 2,524,035 describes a three-electrode semiconductor circuit element using close emitter and collector contacts to translate an input variation into a collector-current variation.

Einstein Relation for Semiconductor Carrier Diffusion

Solid-State Physics & ThermodynamicsClaim 2
Mathematical Governing Law
Terms:
Plain English DecoderHover or tap any highlighted phrase
The is directly proportional to and , scaled by the ratio of to .
DpD_p
Minority Hole Diffusivity
Rate at which injected holes spread thermally through the crystal lattice (~49 cm^2/s in Ge at 300 K)
cm^2/s

Determines how quickly minority holes transit the space-charge inversion layer between emitter and collector.

Physical Principle & Engineering Insight

The Einstein relation bridges thermodynamics and electromagnetism, proving that charge carriers diffuse at a rate dictated solely by their mobility and thermal kinetic energy.

Historical Context: Enabled accurate analytical modeling of bipolar junction and point-contact transistor frequency response.

Carrier injection and collectionAuthored Principle 1
Stated relationIE=f(VE+RfIC);IC=IC0(VC)+aIEI_E = f(V_E + R_f I_C); I_C = I_C^0(V_C) + a I_E
The source presents emitter current as a function of emitter voltage plus the RfIc feedback term, and collector current as its disconnected-emitter value plus a times emitter current. It says a depends on the bias voltages, so this relation does not establish one universal current-gain value.
Electric field across a barrierAuthored Principle 2
Stated relationE≈V/dE ≈ V/d
A reverse collector bias across the very thin surface-layer and barrier region supplies the field that bends current paths and changes collector contact impedance.

Interactive Schematic Sheet (Fig. 1)

The printed drawing shows block 1, plated base 2, surface layer 3, barrier 4, emitter 5, collector 6, and the input/output transformers.

1.00x
US 2,524,035 · FIG. 1n-GeEC
Tap any numbered pin3 Curated Callouts
Callout Pin Inspector

Select Any Numbered Pin

Click pins on the schematic or select from the list below to inspect historical specifications.

Why It Still Matters

The grant documents an early practical solid-state amplifier and articulates the carrier, contact, impedance, and bias relationships that made transistor action an engineered circuit element rather than a rectifier alone.

Legal Claims Decoder (40 Numbered Claims)

Compare dense legalistic claims directly with decoded plain-English functional specifications.
Claim #1Independent Master Claim
1/40
Verbatim Historical Legal Text
“A circuit element which comprises a block of semiconductive material of which the body is of one conductivity type and a thin surface layer is of the opposite conductivity type, an emitter electrode making contact with said layer, a collector electrode making contact with said layer disposed to collect current spreading from said emitter electrode, and a base electrode making contact with the body of the block.”
Plain English Engineering Translation
Claims the core three-terminal element: opposite-type surface layer, emitter and collector on that layer, and a base on the body. The collector is expressly positioned to collect current spreading from the emitter.
Key Protected Innovations:
Opposite-type surface layerClose emitter-collector geometryLow-resistance base

The Historical Bottleneck

The specification seeks amplification and signal translation without a heated cathode or evacuated envelope.

Why Prior Art Failed

  • •Earlier solid rectifier amplifier proposals relied on embedded grids or transverse fields that the specification says were too fine to fabricate successfully.
The Breakthrough Insight
“A close forward emitter and reverse collector can use a surface layer and barrier to couple carrier injection into a high-impedance collector response.”

Patent Wars & Legal Litigations

Vs. William Shockley (Junction Transistor Priority)Infringement Challenge
Rival Claim & Defense:
William Shockley, director of the Bell Labs solid-state physics group, contested Bardeen and Brattain's exclusive inventorship on US 2,524,035, claiming the underlying field-effect concept was his original discovery.
Litigation Conflict:
Shockley isolated himself for four weeks in January 1948 to invent the superior, more reproducible bipolar junction transistor (BJT, US Patent 2,569,347), asserting that junction diffusion made point-contacts obsolete.
Final Resolution & Judicial Outcome:
Bell Labs patent attorneys filed Bardeen and Brattain's point-contact patent with only Bardeen and Brattain as inventors, while filing Shockley's junction transistor patent separately.
Civilizational Impact
The document records an early semiconductor amplifier architecture built around carrier injection, rectifying contacts, and impedance transformation.
Technological Lineage & Descent

The Silicon Microelectronics Revolution

From Punched-Card Tabulators to Multi-Touch Human Interfaces

The digital computation lineage that replaced mechanical gear teeth with point-contact semiconductor switches, monolithic planar circuits, personal computers, and touch glass.

1889Electromechanical Data Storage
US 395,781

Record-Card Statistical Compiler

Conductive mercury cup contacts sensing punched holes in structured card records.

1950Solid-State Transistor OriginThis Patent
US 2,524,035

Bardeen and Brattain Point-Contact Transistor

Point-contact emitter/collector gold cat-whiskers modulating minority carrier diffusion.

1961Planar Monolithic Circuit
US 2,981,877

Oxide-insulated semiconductor leads

Oxide passivation, photolithographic isolation, and evaporated aluminium leads on silicon.

1964Miniaturized Solid Circuit
US 3,138,743

Jack Kilby Monolithic Integrated Circuit

Semiconductor wafer containing active transistors and passive resistive components.

1970Interactive Spatial Input
US 3,541,541

Two-Wheel Position Indicator

Orthogonal rolling wheels driving potentiometers to translate hand motion to screen cursor.

1979Integrated Microcomputer
US 4,136,359

Wozniak Video Timing and Color Circuit

Shared-RAM timing generator enabling flicker-free color microprocessor video generation.

2001Global Information Graph
US 6,285,999

Google PageRank Algorithm

Eigenvector centrality algorithm weighting web document importance by hyperlink graph.

2009Capacitive Gestural Surface
US 7,479,949

Apple iPhone Multi-Touch Heuristics

Mutual capacitance sensor matrix resolving concurrent discrete finger touch trajectories.