Patent US3874377A successfully refreshed from Google Patents.
Patent US5159186A successfully refreshed from Google Patents.
US5159186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoconversion device with capacitive compensation in shielded dark current element
Assignee: Canon Inc
•
Filing: 1991-09-30
•
Granted: 1992-10-27
•
Expires: 2011-09-30
Abstract
Abstract A photoconversion device has light receiving cells and also a dark cell to provide a dark output to enable the signals from the light receiving cells to be compensated for noise due to dark current. The dark cell resembles the light cells, but its light receiving region is covered by a light shielding layer (5). Capacitive coupling between the light shielding layer (5) and a charge accumulation region (3) distorts the dark cell output so that it does not match the dark current noise in the light cell outputs. This capacitive coupling is reduced by interposing a conductive layer (1) between the light shielding layer and the charge accumulation region (2). Preferably the conductive layer (1) is connected to the read-out electrode. Preferably the read-out electrode (1) of the light cells is enlarged to further reduce the difference between the capacitance of the charge accumulation region (2) of the dark cell and that of the light cells.
Inventors
- 👤 Hayao Ohzu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:11
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
90 words
Photoconversion device comprising: a first photoconversion element having a photoconversion region for accumulating carriers caused by incident light; and a second photoconversion element having a photoconversion region for producing dark output that is corresponding to the dark output of said first photoconversion element and having a light shielding region over the photoconversion region, said photoconversion device further comprising a capacitance adjusting means located near the photoconversion region of said second photoconversion element for reducing the difference between the capacitances of said photoconversion regions of said first and second photoconversion elements.
Claim 2
Dependent Claim
90 words
Photoconversion device comprising: a first photoconversion element having a photoconversion region for accumulating carriers caused by incident light; and a second photoconversion element having a photoconversion region for producing dark output that is corresponding to the dark output of said first photoconversion element and having a light shielding region over the photoconversion region, said photoconversion device further comprising a capacitance adjusting means located near the photoconversion region of said second photoconversion element for reducing the difference between the capacitances of said photoconversion regions of said first and second photoconversion elements.
Claim 3
Dependent Claim
15 words
Photoconversion device according to claim 1, wherein said capacitance adjusting means comprises a conductive layer.
Claim 4
Dependent Claim
26 words
Photoconversion device according to claim 2, wherein said conductive layer is located between said light shielding region and said photoconversion region of said second photoconversion element.
Claim 5
Dependent Claim
39 words
Photoconversion device according to claim 1, wherein each said photoconversion element has a control electrode region as the photoconversion region and a main electrode region for outputting a signal corresponding to the carriers accumulated in the control electrode region.
Claim 6
Dependent Claim
42 words
Photoconversion device according to claim 4 further comprising a conductive layer located over a part of said control electrode region of said first photoconversion element wherein said conductive layer and the main electrode region of said first photoconversion element are electrically connected.
Claim 7
Dependent Claim
98 words
A photoconversion device comprising first and second elements, each element comprising a first portion, the first portion of the first element being exposed to light and the first element being for providing an output signal in accordance with the amount of light received by its first portion, and the second element further comprising light shielding means for shielding its first portion from light, the second element being for providing a comparison output signal, the second element further comprising further means for reducing an electrical effect on the comparison output signal of the presence of the light shielding means.
Claim 8
Dependent Claim
98 words
A photoconversion device comprising first and second elements, each element comprising a first portion, the first portion of the first element being exposed to light and the first element being for providing an output signal in accordance with the amount of light received by its first portion, and the second element further comprising light shielding means for shielding its first portion from light, the second element being for providing a comparison output signal, the second element further comprising further means for reducing an electrical effect on the comparison output signal of the presence of the light shielding means.
Claim 9
Dependent Claim
26 words
A photoconversion device according to claim 6 in which the first portion of each said element comprises at least a part of a charge accumulation region.
Claim 10
Dependent Claim
32 words
A photoconversion device according to claim 7 in which the further means reduces the effect of the presence of the light shielding means on an electrical parameter of the charge accumulation region.
Claim 11
Dependent Claim
14 words
A photoconversion device according to claim 8 in which the electrical parameter is capacitance.
Claim 12
Dependent Claim
21 words
A photoconversion device according to claim 6 in which the further means is an electrical conductor or a low dielectric material.
Claim 13
Dependent Claim
20 words
A photoconversion device according to claim 6 in which the further means is electrically isolated from the light shielding means.
Claim 14
Dependent Claim
19 words
A photoconversion device according to claim 6 in which the further means is coupled to a fixed electrical potential.
Claim 15
Dependent Claim
23 words
A photoconversion device according to claim 6 in which the further means is coupled to an electrode for a region of the element.
Claim 16
Dependent Claim
16 words
A photoconversion device according to claim 13 in which the electrode carries the comparison output signal.
Claim 17
Dependent Claim
147 words
A photoconversion device according to claim 6 in which each said element comprises an electrode and the elements have substantially identical arrangements of parts in the vicinity of the electrode, the light shielding means of the second element shielding the vicinity of the electrode from light and the second element further comprising a light shielding means shielding the vicinity of the electrode from light but leaving a part of the first portion unshielded, the electrode of the first element comprising an electrode region having substantially the same size and shape as either (i) the electrode of the second element, or (ii) where a part of the electrode of the second element extends beyond the area corresponding to the area of the first element shielded by the light shielding means of the first element, the part of the electrode of the second element which does not so extend.
Claim 18
Dependent Claim
79 words
A comparison element for a photoconversion device, the element comprising a first portion, which comprises at least a part of a charge accumulation region and light shielding means for shielding the first portion from light, the element providing a comparison output signal in accordance with the amount of charges accumulated in the charge accumulation region, the element further comprising further means for reducing an electrical effect on the comparison output signal of the presence of the light shielding means.
Claim 19
Dependent Claim
79 words
A comparison element for a photoconversion device, the element comprising a first portion, which comprises at least a part of a charge accumulation region and light shielding means for shielding the first portion from light, the element providing a comparison output signal in accordance with the amount of charges accumulated in the charge accumulation region, the element further comprising further means for reducing an electrical effect on the comparison output signal of the presence of the light shielding means.
Claim 20
Dependent Claim
31 words
An element according to claim 16 in which the further means reduces the effect of the presence of the light shielding means on an electrical parameter of the charge accumulation region.
Claim 21
Dependent Claim
13 words
An element according to claim 17 in which the electrical parameter is capacitance.
Claim 22
Dependent Claim
20 words
An element according to claim 16 in which the further means is an electrical conductor or a low dielectric material.
Claim 23
Dependent Claim
19 words
An element according to claim 16 in which the further means is electrically isolated from the light shielding means.
Claim 24
Dependent Claim
18 words
An element according to claim 16 in which the further means is coupled to a fixed electrical potential.
Claim 25
Dependent Claim
22 words
An element according to claim 16 in which the further means is coupled to an electrode for a region of the element.
Claim 26
Dependent Claim
15 words
An element according to claim 22 in which the electrode carries the comparison output signal.
Claim 27
Dependent Claim
94 words
A photoconversion device comprising first and second elements, each element comprising a first portion, the first portion of the first element being exposed to light and the first element being for providing an output in accordance with the amount of light received by its first portion, and the second element further comprising light shielding means for shielding its first portion from light, the second element being for providing a comparison output signal, the second element further comprising a conductive layer or a low dielectric layer between its first portion and the light shielding means.
Claim 28
Dependent Claim
94 words
A photoconversion device comprising first and second elements, each element comprising a first portion, the first portion of the first element being exposed to light and the first element being for providing an output in accordance with the amount of light received by its first portion, and the second element further comprising light shielding means for shielding its first portion from light, the second element being for providing a comparison output signal, the second element further comprising a conductive layer or a low dielectric layer between its first portion and the light shielding means.
Claim 29
Dependent Claim
24 words
A photoconversion device according to claim 24 in which the conductive layer or low dielectric layer is electrically isolated from the light shielding means.
References Cited (Backward Citations)
US4740824A
Cited
US4794279A
Cited
EP0260858A2
Cited
JPS63114254A
Cited
US4905033A
Cited
US4879470A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-27 | 1996-04-27 | 1996-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-27 | 2000-04-27 | 2000-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-27 | 2004-04-27 | 2004-10-27 | $7700.00 | Window Closed / Lapsed |