US4663526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nondestructive readout of a latent electrostatic image formed on an insulating material
Assignee: Optical Diagnostic Systems Inc
•
Filing: 1985-04-03
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Granted: 1987-05-05
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Expires: 2005-04-03
Abstract
Abstract A method and apparatus are described for the nondestructive readout of a latent electrostatic image formed on a sheet or layer of insulating material. A sheet or layer of semiconductor material is disposed in relatively close proximity to the insulating material. The latent electrostatic image formed on the insulating material causes a surface depletion layer to by produced by induction at the surface of the semiconductor material. The location and distribution of the accumulated charges on the semiconductor material are read out as analog electrical signals corresponding to the ac surface photovoltage induced on the semiconductor material as the semiconductor material is scanned with a low intensity modulated light beam of appropriate wavelength, the magnitude of the analog signals depending on the local charge density. The analog electrical signals so obtained are then digitized, processed and stored and/or displayed.
Inventors
- 👤 Emil Kamieniecki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:16
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/28; G01R; G01R29/00; G01R29/24; G01R31/00; G01R31/26; G01R31/265; G01R31/2656; G01T1/24; G01T1/246; G03; G03G; G03G15/00; G03G15/054; G03G15/22; G03G15/221; G03G5/00; G03G5/02
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
106 words
A method of reading out accumulated charges on an insulator without destroying the accumulated charges, the method comprising: a. providing a semiconductor which is conductive in the dark, b. positioning the insulator relative to the semiconductor such that the accumulated charges on the insulator are in close proximity to but not in contact with the semiconductor, the accumulated charges on the insulator inducing a depletion layer in the semiconductor, the accumulated charges in the depletion layer in the semiconductor being related to the accumulated charges on the insulator, and c. detecting the magnitude and location of the accumulated charges in the depletion layer in the semiconductor.
Claim 2
Independent Claim
106 words
A method of reading out accumulated charges on an insulator without destroying the accumulated charges, the method comprising: a. providing a semiconductor which is conductive in the dark, b. positioning the insulator relative to the semiconductor such that the accumulated charges on the insulator are in close proximity to but not in contact with the semiconductor, the accumulated charges on the insulator inducing a depletion layer in the semiconductor, the accumulated charges in the depletion layer in the semiconductor being related to the accumulated charges on the insulator, and c. detecting the magnitude and location of the accumulated charges in the depletion layer in the semiconductor.
Claim 3
Dependent Claim
30 words
The method of claim 1 and wherein detecting the magnitude and location of the accumulated charges in the depletion layer in the semiconductor comprises using the ac surface photovoltage effect.
Claim 4
Dependent Claim
38 words
The method of claim 2 and wherein using the ac surface photovoltage effect comprises providing a reference electrode, illuminating the semiconductor with a beam of light and measuring the photovoltage signal across the reference electrode and the semiconductor.
Claim 5
Dependent Claim
14 words
The method of claim 3 and wherein the beam of light is intensity modulated.
Claim 6
Dependent Claim
16 words
The method of claim 4 and wherein the beam of light is scanning over the semiconductor.
Claim 7
Dependent Claim
24 words
The method of claim 27 and wherein the reference electrode is positioned such that the insulator is between the reference electrode and the semiconductor.
Claim 8
Dependent Claim
17 words
The method of claim 6 and wherein the reference electrode is transparent to the beam of light.
Claim 9
Dependent Claim
30 words
The method of claim 7 and further providing a protective insulating layer between the semiconductor and the insulator for preventing the flow of charges between the insulator and the semiconductor.
Claim 10
Dependent Claim
15 words
The method of claim 8 and wherein the semiconductor is scanned through the reference electrode.
Claim 11
Dependent Claim
34 words
The method of claim 9 and wherein the semiconductor has a top and a bottom, the depletion layer induced in the semiconductor is near the top and the semiconductor is scanned through the bottom.
Claim 12
Dependent Claim
11 words
The method of claim 10 and wherein said insulator is photoconductive.
Claim 13
Dependent Claim
14 words
The method of claim 11 and further including digitizing the photovoltage signals so generated.
Claim 14
Dependent Claim
18 words
The method of claim 12 and wherein the accumulated charges are formed on the insulator by the radiation.
Claim 15
Dependent Claim
22 words
The method of claim 13 and wherein the scanning beam of light is of photon energy that will interact with the semiconductor.
Claim 16
Dependent Claim
12 words
The method of claim 1 and wherein the semiconductor is a wafer.
Claim 17
Dependent Claim
18 words
The method of claim 1 and wherein the semiconductor and the insulator are both films on a substrate.
Claim 18
Dependent Claim
21 words
The method of claim 1 and wherein the semiconductor is a wafer and the insulator is a film on the wafer.
Claim 19
Dependent Claim
104 words
Apparatus for use in reading out accumulated charges on an insulator without destroying the accumulated charges, the apparatus comprising: a. a semiconductor, said semiconductor being conductive in the dark and being disposed in relatively close proximity to but not in contact with the accumulated charges on the insulator such that a depletion layer related to the accumulated charges on the insulator is induced in the semiconductor, b. a reference electrode, and c. means for scanning said semiconductor with a beam of light, the beam of light producing an electrical signal between the semiconductor and the reference electrode corresponding to charges induced in the semiconductor.
Claim 20
Dependent Claim
104 words
Apparatus for use in reading out accumulated charges on an insulator without destroying the accumulated charges, the apparatus comprising: a. a semiconductor, said semiconductor being conductive in the dark and being disposed in relatively close proximity to but not in contact with the accumulated charges on the insulator such that a depletion layer related to the accumulated charges on the insulator is induced in the semiconductor, b. a reference electrode, and c. means for scanning said semiconductor with a beam of light, the beam of light producing an electrical signal between the semiconductor and the reference electrode corresponding to charges induced in the semiconductor.
Claim 21
Dependent Claim
16 words
The apparatus of claim 18 and wherein the semiconductor is in the form of a plate.
Claim 22
Dependent Claim
12 words
The apparatus of claim 19 and wherein the plate is a wafer.
Claim 23
Dependent Claim
16 words
The apparatus of claim 18 and wherein the semiconductor is in the form of a film.
Claim 24
Dependent Claim
18 words
The apparatus of claim 18 and wherein the semiconductor and the insulator are both films on a substrate.
Claim 25
Dependent Claim
21 words
The apparatus of claim 18 and wherein the semiconductor is a plate and the insulator is a film on said plate.
Claim 26
Dependent Claim
29 words
The apparatus of claim 18 and wherein the semiconductor is selected from the group consisting of microcrystalline silicon, polycrystalline silicon, amorphous silicon, alloys of silicon and alloys of silicon-germanium.
Claim 27
Dependent Claim
15 words
The apparatus of claim 18 and further including a protective insulating layer on the semiconductor.
Claim 28
Dependent Claim
14 words
The apparatus of claim 25 and wherein the beam of light is intensity modulated.
Claim 29
Dependent Claim
14 words
The apparatus of claim 26 and further including an electrical contact on the semiconductor.
Claim 30
Dependent Claim
29 words
The apparatus of claim 18 and wherein the reference electrode comprises: a. a transparent nonconductive substrate, and b. a plurality of parallel stripes of conductive material on said substrate.
Claim 31
Dependent Claim
52 words
The apparatus of claim 18 and wherein the reference electrode comprises: a. a substrate of transparent nonconductive material, b. a uniform layer of photoconductive insulating material on top of the substrate, and c. a pluraity of parallel stripes of conductive material sandwiched between the substrate and the layer of photoconductive insulating material.
Claim 32
Dependent Claim
116 words
Apparatus for use in reading out accumulated charges on an insulator, the apparatus comprising: a. a semiconductor which is conductive in the dark, said semiconductor being disposed on one side of the insulator in relatively close proximity but not in contact with the accumulated charges on the insulator such that a depletion layer is induced thereon related to the accumulated changes on the insulator; b. a reference electrode on the other side of the insulator, c. means for scanning the semiconductor with a beam of light, the beam of light producing an electrical signal between the semiconductor and the reference electrode corresponding to charges induced on the semiconductor, and d. means for detecting the electrical signal.
Claim 33
Dependent Claim
116 words
Apparatus for use in reading out accumulated charges on an insulator, the apparatus comprising: a. a semiconductor which is conductive in the dark, said semiconductor being disposed on one side of the insulator in relatively close proximity but not in contact with the accumulated charges on the insulator such that a depletion layer is induced thereon related to the accumulated changes on the insulator; b. a reference electrode on the other side of the insulator, c. means for scanning the semiconductor with a beam of light, the beam of light producing an electrical signal between the semiconductor and the reference electrode corresponding to charges induced on the semiconductor, and d. means for detecting the electrical signal.
Claim 34
Independent Claim
103 words
A method of reading out accumulated charges on an insulator without destroying said accumulated charges, the method comprising: a. providing a semiconductor which is conductive in the dark, b. forming a depletion layer in the semiconductor, c. positioning the semiconductor in close proximity to, but not in contact with the insulator so that accumulated charges on the insulator cause a change in the depletion layer in the semiconductor, said change in the depletion layer in the semiconductor being related to the accumulated charges on the insulator, and d. detecting the magnitude and location of the changes in the depletion layer in the semiconductor.
Claim 35
Independent Claim
103 words
A method of reading out accumulated charges on an insulator without destroying said accumulated charges, the method comprising: a. providing a semiconductor which is conductive in the dark, b. forming a depletion layer in the semiconductor, c. positioning the semiconductor in close proximity to, but not in contact with the insulator so that accumulated charges on the insulator cause a change in the depletion layer in the semiconductor, said change in the depletion layer in the semiconductor being related to the accumulated charges on the insulator, and d. detecting the magnitude and location of the changes in the depletion layer in the semiconductor.
Claim 36
Dependent Claim
29 words
The method of claim 31 and wherein detecting the magnitude and location of the changes in the depletion layer in the semiconductor comprises using the ac surface photovoltage effect.
Claim 37
Dependent Claim
38 words
The method of claim 32 and wherein using the ac surface photovoltage effect comprises providing a reference electrode, illuminating the semiconductor with a beam of light and measuring electrical signals generated between the reference electrode and the semiconductor.
Claim 38
Independent Claim
108 words
A method of reading out accumulated charges in a first layer of insulating material, said first layer of insulating material being on top of a second layer of insulating material, said second layer of insulating material being on top of a layer of semiconductor material, said layer of semiconductor material being conductive in the dark and being on the top surface of a substrate, said accumulated charges in said first layer of insulating material inducing a depletion layer in said layer of semiconductor material, said method comprising: a. providing a reference electrode, and b. measuring the surface photovoltage between the layer of semiconductor material and the reference electrode.
Claim 39
Independent Claim
108 words
A method of reading out accumulated charges in a first layer of insulating material, said first layer of insulating material being on top of a second layer of insulating material, said second layer of insulating material being on top of a layer of semiconductor material, said layer of semiconductor material being conductive in the dark and being on the top surface of a substrate, said accumulated charges in said first layer of insulating material inducing a depletion layer in said layer of semiconductor material, said method comprising: a. providing a reference electrode, and b. measuring the surface photovoltage between the layer of semiconductor material and the reference electrode.
Claim 40
Independent Claim
135 words
A method of reading out accumulated charges on a sheet of insulating material without destroying the accumulated charges, the method comprising: a. providing a sheet of semiconductor material which is conductive in the dark, b. positioning the sheet of insulating material relative to the sheet of semiconductor materials such that the accumulated charges on the sheet of insulating material are in close proximity to but not in contact with the sheet of semiconductor material, the accumulated charges on the sheet of insulating material including a depletion layer in the sheet of semiconductor material, the accumulated charges in the depletion layer in the sheet of semiconductor material being related to the accumulated charges in the sheet of insulating material, and c. detecting the magnitude and location of the accumulated charges in the sheet of semiconductor material.
Claim 41
Independent Claim
135 words
A method of reading out accumulated charges on a sheet of insulating material without destroying the accumulated charges, the method comprising: a. providing a sheet of semiconductor material which is conductive in the dark, b. positioning the sheet of insulating material relative to the sheet of semiconductor materials such that the accumulated charges on the sheet of insulating material are in close proximity to but not in contact with the sheet of semiconductor material, the accumulated charges on the sheet of insulating material including a depletion layer in the sheet of semiconductor material, the accumulated charges in the depletion layer in the sheet of semiconductor material being related to the accumulated charges in the sheet of insulating material, and c. detecting the magnitude and location of the accumulated charges in the sheet of semiconductor material.
Claim 42
Dependent Claim
29 words
The method of claim 35 and wherein detecting the magnitude and location of the accumulated charges in the sheet of semiconductor material comprises using the ac surface photovoltage effect.
Claim 43
Independent Claim
67 words
A device for use in recording and reading out a charge distribution pattern comprising: a. a substrate of conductive material, b. a layer of semiconductor material on top of the substrate, the layer of semiconductor material being conductive in the dark, c. a protective insulative layer on top of the layer of semiconductive material, and d. a photoconductive insulating layer on top of the protective insulating layer.
Claim 44
Independent Claim
67 words
A device for use in recording and reading out a charge distribution pattern comprising: a. a substrate of conductive material, b. a layer of semiconductor material on top of the substrate, the layer of semiconductor material being conductive in the dark, c. a protective insulative layer on top of the layer of semiconductive material, and d. a photoconductive insulating layer on top of the protective insulating layer.
Claim 45
Dependent Claim
20 words
The device of claim 37 and wherein the reference electrode comprises a plurality of conductive stripes on a transparent substrate.
Claim 46
Dependent Claim
15 words
The device of claim 37 and wherein the reference electrode is a transparent conductive material.
Claim 47
Dependent Claim
21 words
A photoreceptor comprising: a. a semiconductor, b. a protective insulator on the semiconductor, c. a photoconductive insulator on the protective insulator.
Claim 48
Dependent Claim
21 words
A photoreceptor comprising: a. a semiconductor, b. a protective insulator on the semiconductor, c. a photoconductive insulator on the protective insulator.
Claim 49
Dependent Claim
43 words
A photoreceptor comprising: a. a wafer of semiconductor material, having a top surface and a bottom surface, b. a protective insulating layer on the top surface of the wafer, and c. a metal electrode above and spaced apart from the protective insulating layer.
Claim 50
Dependent Claim
43 words
A photoreceptor comprising: a. a wafer of semiconductor material, having a top surface and a bottom surface, b. a protective insulating layer on the top surface of the wafer, and c. a metal electrode above and spaced apart from the protective insulating layer.
Claim 51
Dependent Claim
18 words
The photoreceptor of claim 41 and wherein the wafer is a semiconductor having a single type of dopant.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |