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US4714836A Expired / Lapsed US ⏱️ 0.0 years remaining

Photosensitive pixel with exposed blocking element

Assignee: Nippon Steel Corp
•
Filing: 1986-09-16
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Granted: 1987-12-22
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Expires: 2006-09-16
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Abstract

Abstract By maintaining the first electrodes of a photogenerative element and a current blocking element at a common potential while electrically interconnecting the second electrodes thereof, the blocking element need not be masked from incident radiation because the stored electrical signal generated by the photogenerative element will not be dissipated by photogenerated carrier pairs contributed by the current blocking element.

Inventors

  • 👤 Koichi Kitamura
  • 👤 Louis D. Swartz
  • 👤 Clive Catchpole
  • 👤 Zvi Yaniv

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 20:50
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40056; H10; H10D; H10D44/00; H10D44/40; H10D44/45; H10D44/452; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18

Claims Analysis

Total Claims: 28
Claim 1
Independent Claim 113 words
A circuit for providing a detectable signal corresponding to the quantity of radiation incident upon a photosensitive pixel, the circuit comprising: a photogenerative element including at least first and second electrodes; means for selectively blocking current flow through at least a portion of the circuit, said blocking means including at least first and second electrodes; the first electrode of the photogenerative element and the first electrode of the blocking means being electrically interconnected; and the second electrode of the photogenerative element and the second electrode of the blocking means held substantially at a common potential; whereby the stored detectable signal will not be dissipated by carrier pairs photogenerated by unmasked current blocking means.
Claim 2
Dependent Claim 113 words
A circuit for providing a detectable signal corresponding to the quantity of radiation incident upon a photosensitive pixel, the circuit comprising: a photogenerative element including at least first and second electrodes; means for selectively blocking current flow through at least a portion of the circuit, said blocking means including at least first and second electrodes; the first electrode of the photogenerative element and the first electrode of the blocking means being electrically interconnected; and the second electrode of the photogenerative element and the second electrode of the blocking means held substantially at a common potential; whereby the stored detectable signal will not be dissipated by carrier pairs photogenerated by unmasked current blocking means.
Claim 3
Dependent Claim 13 words
A circuit as in claim 1, wherein said photogenerative element is a photoresistor.
Claim 4
Dependent Claim 13 words
A circuit as in claim 1, wherein said photogenerative element is a phototransistor.
Claim 5
Dependent Claim 13 words
A circuit as in claim 1, wherein said photogenerative element is a photodiode.
Claim 6
Dependent Claim 20 words
A circuit as in claim 4, wherein said photodiode includes oppositely doped layers formed of thin film semiconductor alloy material.
Claim 7
Dependent Claim 34 words
A circuit as in claim 5, wherein said photodiode further includes a layer formed of substantially intrinsic semiconductor alloy material interposed between said oppositely doped layers so as to form a p-i-n type photodiode.
Claim 8
Dependent Claim 44 words
A circuit as in claim 6, wherein at least one of the semiconductor layers of said p-i-n type photodiode is formed from a material chosen from the group consisting essentially of: amorphous silicon alloy materials, amorphous germanium alloy materials, and amorphous silicon:germanium alloy materials.
Claim 9
Dependent Claim 24 words
A circuit as in claim 6, wherein said photogenerative element includes a plurality of p-i-n type photodiodes stacked in optical and electrical series relationship.
Claim 10
Dependent Claim 32 words
A circuit as in claim 1, wherein said blocking means includes a layer of photoresponsive semiconductor alloy material capable of generating charge carrier pairs in response to the absorption of incident radiation.
Claim 11
Dependent Claim 13 words
A circuit as in claim 1, wherein said blocking means is a transistor.
Claim 12
Dependent Claim 13 words
A circuit as in claim 1, wherein said blocking means is a diode.
Claim 13
Dependent Claim 22 words
A circuit as in claim 11, wherein said diode includes a pair of oppositely doped layers of thin film semiconductor alloy material.
Claim 14
Dependent Claim 31 words
A circuit as in claim 12, wherein said diode includes a layer of intrinsic semiconductor alloy material interposed between said oppositely doped layers so as to provide a p-i-n type diode.
Claim 15
Dependent Claim 40 words
A circuit as in claim 13, wherein said p-i-n type diode includes at least one layer of semiconductor alloy material chosen from the group consisting essentially of: amorphous silicon alloy materials, amorphous germanium alloy materials, and amorphous silicon:germanium alloy materials.
Claim 16
Dependent Claim 24 words
A circuit as in claim 13, wherein said diode comprises a plurality of stacked p-i-n type diodes disposed in optical and electrical series relationship.
Claim 17
Dependent Claim 14 words
A circuit as in claim 11, wherein said diode is a Schottky barrier diode.
Claim 18
Dependent Claim 16 words
A circuit as in claim 1, wherein said blocking means is substantially unshielded from incident radiation.
Claim 19
Dependent Claim 32 words
A circuit as in claim 1, further including means for maintaining the second electrode of the photogenerative element and the second electrode of the current blocking means at a substantially equal potential.
Claim 20
Dependent Claim 21 words
A circuit as in claim 18, wherein said potential maintaining means is adapted to maintain a potential of approximately 0 volts.
Claim 21
Dependent Claim 17 words
A circuit as in claim 18, wherein said potential maintaining means includes a low impedance current amplifier.
Claim 22
Dependent Claim 95 words
A circuit as in claim 1, wherein said photogenerative element is a photodiode having an anode and a cathode; said blocking means is a blocking diode having an anode and cathode; the cathodes of the two diodes electrically interconnected by an electrical conductor so that upon exposure of the photodiode to radiation, an electrical signal in the form of photogenerated carrier pairs will be stored on said electrical conductor; and the anode of the photodiode and the anode of the blocking diode maintained at substantially similar electrical potentials while the circuit is exposed to radiation.
Claim 23
Dependent Claim 13 words
A circuit as in claim 21, wherein said blocking diode is a photodiode.
Claim 24
Dependent Claim 33 words
A circuit as in claim 22, wherein said photodiode and said blocking diode include p-i-n layers of thin film semiconductor alloy material of substantially similar thickness so as to facilitate the fabrication thereof.
Claim 25
Dependent Claim 45 words
A circuit as in claim 23, further comprising a plurality of photodiodes and a plurality of associated blocking diodes operatively disposed and arranged for use as an array of photosensitive pixels, each pixel providing an electrical signal corresponding to the quantity of radiation incident thereupon.
Claim 26
Dependent Claim 13 words
A circuit as in claim 24, wherein said array of pixels is linear.
Claim 27
Dependent Claim 16 words
A circuit as in claim 24, wherein said array of pixels is a two dimensional matrix.
Claim 28
Dependent Claim 26 words
A circuit as in claim 21, wherein the relative surface area of the blocking diode to the photodiode differs by a factor of at least 5.

References Cited (Backward Citations)

US4500924A Cited
US4675739A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-12-21 1991-06-22 1991-12-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-12-21 1995-06-22 1995-12-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-12-21 1999-06-22 1999-12-22 $7700.00 Window Closed / Lapsed

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