US3928864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear display device
Assignee: US Philips Corp
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Filing: 1973-12-18
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Granted: 1975-12-23
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Expires: 1993-12-18
Abstract
Abstract A solid-state display device or indicator producing a luminous column is described. The device includes an elongated semiconductor electro-luminescent diode, an insulator on the surface, and a resistance layer on the insulator. The diode junction is forward biased to produce a luminous column. The voltage to be indicated is applied to the resistance layer to establish a gradient therein which tends to move carriers in the semiconductor from an area of radiative bulk recombination to an area of non-radiative recombination, thereby reducing or extinguishing the column end in relation to the magnitude of the applied voltage.
Inventors
- 👤 Jacques Fertin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:45
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H10; H10H; H10H20/00; H10H20/062; H10H20/80
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
257 words
A DEVICE COMPRISING AN ELECTROLUMINESCENT DIODE HAVING AN ELONGATED FIRST REGION OF A FIRST CONDUCTIVITY TYPE, AN ELONGATED SECOND REGION OF THE OPPOSITE CONDUCTIVITY TYPE EXTENDING ON THE FIRST REGION AND FORMING THEREWITH A P-N JUNCTION AND SHOWING ELECTROLUMINESCENT PROPERTIES WHEN CHARGE CARRIERS ARE INJECTED INTO IT, ELECTRODE, CONNECTIONS TO THE FIRST AND SECOND REGIONS, A THIN ELONGATED INSULATED LAYER EXTENDING ON THE SAID SECOND REGION AND OVER AND PARALLEL TO SAID P-N JUNCTION TION, AN ELONGATED RESISTANCE LAYER EXTENDING ON THE SAID INSULATING LAYER AND OVER SAID P-N JUNCTION, SAID RESISTANCE LAYER AND SAID INSULATING LAYER BEING TRANSPARENT TO THE RADIATION EMITTED FROM SAID SECOND REGION, MEANS CONNECTED TO THE FIRST AND SECOND REGION ELECTRODE CONNECTIONS TO FORWARD BIAS THE JUNCTION CAUSING THE INJECTION OF CHARGE CARRIERS INTO THE SECOND REGION ALONG ITS LENGTH WHEREBY SAID CARRIERS RECOMBINE IN THE SECOND REGION BULK AND RADIATION IS EMITTED, SAID MEANS BEING CAPABLE OF ESTABLISHING A COLUMN OF RADIATION ALONG THE LENGTH OF THE DEVICE, AND MEANS TO ESTABLISH A POTENTIAL DIFFERENCE BETWEEN ONE END OF SAID RESISTANCE LAYER AND SAID SECOND REGION AND TO CAUSE A POTENTIAL GRADIENT ALONG THE LENGTH OF AND IN THE DIRECTION OF THE OTHER END OF SAID RESISTANCE LAYER, SAID POTENTIAL DIFFERENCE BEING SUCH AS TO DRIVE THE INJECTED CARRIERS IN ACCORDANCE WITH ITS MAGNITUDE TOWARD THE SURFACE OF THE SECOND REGION WHERE THEY TEND TO RECOMBINE IN A NONRADIATIVE MANNER THEREBY REDUCING THE RADIATION THEREAT, WHEREBY THE LENGTH OF THE RADIATION COLUMN IS RELATED TO THE VALUE OF THE POTENTIAL DIFFERENCE.
Claim 2
Independent Claim
257 words
A DEVICE COMPRISING AN ELECTROLUMINESCENT DIODE HAVING AN ELONGATED FIRST REGION OF A FIRST CONDUCTIVITY TYPE, AN ELONGATED SECOND REGION OF THE OPPOSITE CONDUCTIVITY TYPE EXTENDING ON THE FIRST REGION AND FORMING THEREWITH A P-N JUNCTION AND SHOWING ELECTROLUMINESCENT PROPERTIES WHEN CHARGE CARRIERS ARE INJECTED INTO IT, ELECTRODE, CONNECTIONS TO THE FIRST AND SECOND REGIONS, A THIN ELONGATED INSULATED LAYER EXTENDING ON THE SAID SECOND REGION AND OVER AND PARALLEL TO SAID P-N JUNCTION TION, AN ELONGATED RESISTANCE LAYER EXTENDING ON THE SAID INSULATING LAYER AND OVER SAID P-N JUNCTION, SAID RESISTANCE LAYER AND SAID INSULATING LAYER BEING TRANSPARENT TO THE RADIATION EMITTED FROM SAID SECOND REGION, MEANS CONNECTED TO THE FIRST AND SECOND REGION ELECTRODE CONNECTIONS TO FORWARD BIAS THE JUNCTION CAUSING THE INJECTION OF CHARGE CARRIERS INTO THE SECOND REGION ALONG ITS LENGTH WHEREBY SAID CARRIERS RECOMBINE IN THE SECOND REGION BULK AND RADIATION IS EMITTED, SAID MEANS BEING CAPABLE OF ESTABLISHING A COLUMN OF RADIATION ALONG THE LENGTH OF THE DEVICE, AND MEANS TO ESTABLISH A POTENTIAL DIFFERENCE BETWEEN ONE END OF SAID RESISTANCE LAYER AND SAID SECOND REGION AND TO CAUSE A POTENTIAL GRADIENT ALONG THE LENGTH OF AND IN THE DIRECTION OF THE OTHER END OF SAID RESISTANCE LAYER, SAID POTENTIAL DIFFERENCE BEING SUCH AS TO DRIVE THE INJECTED CARRIERS IN ACCORDANCE WITH ITS MAGNITUDE TOWARD THE SURFACE OF THE SECOND REGION WHERE THEY TEND TO RECOMBINE IN A NONRADIATIVE MANNER THEREBY REDUCING THE RADIATION THEREAT, WHEREBY THE LENGTH OF THE RADIATION COLUMN IS RELATED TO THE VALUE OF THE POTENTIAL DIFFERENCE.
Claim 3
Dependent Claim
32 words
A device as claimed in claim 1 and comprising non-rectifying contacts at the two ends of the resistance layer, and means connecting one of the resistance layer ends to the second region.
Claim 4
Dependent Claim
48 words
A device as claimed in claim 1 and comprising a single non-rectifying contact at said one end of the resistance layer, the length resistance of the resistance layer taken between the two ends being significantly higher than the transverse resistance of the insulating layer taken along its thickness.
Claim 5
Dependent Claim
34 words
A device as claimed in claim 3, wherein the ratio between the said longitudinal resistance of the resistance layer and the said transverse resistance of the insulating layer is at least equal to 10.
Claim 6
Dependent Claim
42 words
A device as claimed in claim 1 and comprising a non-rectifying contact at said one end of said resistance layer and a non-rectifying contact on the part of the second region which is present below the other end of said resistance layer.
Claim 7
Dependent Claim
62 words
A device as claimed in claim 1 and comprising a non-rectifying contact at said one end of said resistance layer, a non-rectifying contact on a part of the second region which is present below said one end, and a connection which connects the other end of the resistance layer to the part of the second region which lies below the other end.
Claim 8
Dependent Claim
27 words
A device as claimed in claim 1, wherein the ratio between the length and the average width of the resistance layer is at least equal to 10.
Claim 9
Dependent Claim
47 words
A device as claimed in claim 7, wherein the first region is of the n- conductivity type and the second region is of the p-conductivity type, the thickness of the second region lying between one and ten times the diffusion length for electrons in the second region.
Claim 10
Dependent Claim
55 words
A device as claimed in claim 8, wherein for at least a value of the applied potential difference the distance between the P-N junction and the surface of the second region which lies below said one end of the resistance layer is smaller than the diffusion length for minority carriers in the said second region.
Claim 11
Dependent Claim
22 words
A device as claimed in claim 1, wherein the length of the radiation column varies inversely proportionally with the applied potential difference.
Claim 12
Dependent Claim
36 words
A device as claimed in claim 1, wherein the first region and the second region are constituted of III-V semiconductor materials, the insulating layer is of silicon oxide, and the resistance layer is of indium oxide.
Claim 13
Dependent Claim
16 words
A device as claimed in claim 1, wherein the biasing means comprises a constant current generator.
Claim 14
Independent Claim
279 words
A method of displaying a voltage value comprising providing a device including an electroluminescent diode having an elongated first region of a first conductivity type, an elongated second region of the opposite conductivity type extending on the first region and forming therewith a P-N junction and showing electroluminescent properties when charge carriers are injected into it, electrode connections to the first and second regions, a thin elongated insulated layer extending on the said second region and over and parallel to said P-N junction, and an elongated resistance layer extending on the said insulating layer and over said P-N junction, said resistance layer and said insulating layer being transparent to the radiation emitted from said second region, said diode emitting radiation when charge carriers injected into the second region recombine in the second region bulk, whereas carriers driven toward the surface of the second region tend to recombine in a non-radiative manner, comprising the steps of applying across the first and second region electrodes a constant current voltage which forward biases the P-N junction and causes injection of charge carriers into the second region along the length thereof, said voltage being such as to cause the said length of the second region to become luminous, and applying between one end of said resistance layer and the second region a signal voltage causing a potential gradient in the resistance layer and a field in the second region which in accordance with its value attracts the injected charge carriers toward the surface whereat they tend to undergo non-radiative recombination whereby the end of the second region reduces in luminosity, the total luminous length thus being inversely related to the signal voltage magnitude.
Claim 15
Independent Claim
279 words
A method of displaying a voltage value comprising providing a device including an electroluminescent diode having an elongated first region of a first conductivity type, an elongated second region of the opposite conductivity type extending on the first region and forming therewith a P-N junction and showing electroluminescent properties when charge carriers are injected into it, electrode connections to the first and second regions, a thin elongated insulated layer extending on the said second region and over and parallel to said P-N junction, and an elongated resistance layer extending on the said insulating layer and over said P-N junction, said resistance layer and said insulating layer being transparent to the radiation emitted from said second region, said diode emitting radiation when charge carriers injected into the second region recombine in the second region bulk, whereas carriers driven toward the surface of the second region tend to recombine in a non-radiative manner, comprising the steps of applying across the first and second region electrodes a constant current voltage which forward biases the P-N junction and causes injection of charge carriers into the second region along the length thereof, said voltage being such as to cause the said length of the second region to become luminous, and applying between one end of said resistance layer and the second region a signal voltage causing a potential gradient in the resistance layer and a field in the second region which in accordance with its value attracts the injected charge carriers toward the surface whereat they tend to undergo non-radiative recombination whereby the end of the second region reduces in luminosity, the total luminous length thus being inversely related to the signal voltage magnitude.
References Cited (Backward Citations)
US3492548A
Cited
US3558897A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |