Patent US1779116A successfully refreshed from Google Patents.
US6097024A
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US
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Moisture sensor and windshield fog detector
Assignee: Gentex Corp
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Filing: 1999-07-02
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Granted: 2000-08-01
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Expires: 2019-07-02
Abstract
Abstract A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield. By providing a system for automatically detecting the presence of fog on the interior and exterior of the windshield, serious performance limitations of known automatic rain sensors are eliminated.
Inventors
- 👤 Joseph S. Stam
- 👤 Jon H. Bechtel
- 👤 John K. Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:59
CPC Classifications
B; B60; B60S; B60S1/00; B60S1/02; B60S1/04; B60S1/06; B60S1/08; B60S1/0818; B60S1/0822; B60S1/0833; B60S1/0844; B60S1/0874; B60S1/0885; B60S1/0888; G; G06; G06T; G06T7/00; G06T7/40; G06T7/41; G06T7/42; G06V; G06V20/00; G06V20/50; G06V20/56; H; H04; H04N; H04N23/00; G06T2207/00; G06T2207/20; G06T2207/20048; G06T2207/20056; G06T2207/30; G06T2207/30248; G06T2207/30252; Y; Y10; Y10S; Y10S15/00; Y10S15/15; Y10S318/00; Y10S318/02
Claims Analysis
Total Claims: 88
Claim 1
Independent Claim
76 words
A system for detecting moisture on a surface, comprising: an array image sensor; an optical system to image a portion of the surface onto the array image sensor; and a processing system coupled to the array image sensor, the processing system analyzing images from the array image sensor to detect moisture, wherein the processing system alternately processes the images from different subwindows of the array image sensor, the subwindows being smaller than the array image sensor.
Claim 2
Independent Claim
76 words
A system for detecting moisture on a surface, comprising: an array image sensor; an optical system to image a portion of the surface onto the array image sensor; and a processing system coupled to the array image sensor, the processing system analyzing images from the array image sensor to detect moisture, wherein the processing system alternately processes the images from different subwindows of the array image sensor, the subwindows being smaller than the array image sensor.
Claim 3
Dependent Claim
25 words
The system of claim 1, wherein the processing system receives pixel information from only a subwindow of the array image sensor during a sampling interval.
Claim 4
Dependent Claim
27 words
The system of claim 1, wherein the processing system includes a memory, the memory storing pixel information associated with the received subwindow of the array image sensor.
Claim 5
Dependent Claim
39 words
The system of claim 3, wherein the memory includes a random access memory having a capacity less than that required to store pixel information for the entire array image sensor and sufficient to store information for the received subwindow.
Claim 6
Dependent Claim
35 words
The system of claim 1, wherein the array image sensor includes a windowing feature to alternately image different regions of the image array sensor smaller than the entire imaging area of the array image sensor.
Claim 7
Dependent Claim
35 words
The system of claim 1, wherein the optical system causes at least a portion of the surface to be focused on the array image sensor and blurs objects at a distance greater than the surface.
Claim 8
Dependent Claim
16 words
The system of claim 1, wherein the processing system determines the spatial composition of subwindow images.
Claim 9
Dependent Claim
23 words
The system of claim 7, wherein the processing system determines the spatial composition of subwindow images by determining the high spatial frequency components.
Claim 10
Dependent Claim
22 words
The system of claim 7, wherein the processing system determines the spatial composition of subwindow images by analyzing edges in the subwindow.
Claim 11
Dependent Claim
18 words
The system of claim 1, wherein the array image sensor comprises fewer than approximately 64 rows of pixels.
Claim 12
Dependent Claim
25 words
The system of claim 1, where in the array image sensor comprises a pixel array including approximately 50 to 64 rows and columns of pixels.
Claim 13
Dependent Claim
23 words
The system of claim 1, wherein the surface area imaged by the array image sensor is less than approximately 1000 mm 2 .
Claim 14
Dependent Claim
29 words
The system of claim 1, wherein the image array sensor is positioned with a top of the array positioned closer to the surface than the bottom of the array.
Claim 15
Dependent Claim
27 words
The system of claim 1, wherein the sensitivity of the array image sensor is reduced during high ambient light conditions and increased during low ambient light condition.
Claim 16
Dependent Claim
25 words
The system of claim 14, wherein the sensitivity of the array image sensor is varied by changing an integration interval for pixels in the sensor.
Claim 17
Dependent Claim
30 words
The system of claim 14, wherein the sensitivity of the array image sensor is varied depending upon the average gray scale of pixels in an image in a previous cycle.
Claim 18
Dependent Claim
28 words
The system of claim 14, wherein an ambient light measurement is made as a function of the gray scale values of at least a portion of the pixels.
Claim 19
Dependent Claim
27 words
The system of claim 17, wherein the ambient light measurement is a function of the average gray scale value of at least a portion of the pixels.
Claim 20
Dependent Claim
22 words
The system of claim 1, wherein the image array sensor is a low resolution image array sensor having a plurality of pixels.
Claim 21
Dependent Claim
25 words
The system of claim 19, wherein the ratio of the number of pixels to the imaged area in square millimeters is approximately 4 to 1.
Claim 22
Dependent Claim
15 words
The system of claim 19, wherein the image array sensor includes approximately 40 μm pixels.
Claim 23
Dependent Claim
28 words
The system of claim 19, wherein the ratio of the size of a pixel in μm to the imaged area in square meters is approximately 40 to 1.
Claim 24
Dependent Claim
44 words
The system of claim 1, further including a wiping system and an actuation signal for the wiping system, the processing system to analyze an image taken after generation of the actuation signal to generate a value representative of the spatial composition on the surface.
Claim 25
Dependent Claim
42 words
The system of claim 1, wherein the processing system is operative to analyze images from the image sensor to detect long term spatial components on at least a portion of the surface and to distinguish moisture components from the long term components.
Claim 26
Dependent Claim
24 words
The system of claim 1, wherein the processing system ignores pixels in the array image sensor producing a gray scale value above a threshold.
Claim 27
Dependent Claim
36 words
The system of claim 1, wherein the processing system analyzes at least one sub window of the array image sensor more frequently than other portions of the array image sensor in order to detect a condition.
Claim 28
Dependent Claim
37 words
The system of claim 26, wherein the processing system is selectively responsive to the array image sensor following actuation of the wiper for detecting whether the wiper has moved over at least a portion of the surface.
Claim 29
Independent Claim
106 words
A method of detecting moisture on a surface, using a system including an image sensor, an optical system operative to focus at least a portion of the surface onto the image sensor, a wiping system operative to remove moisture from at least a portion of the surface imaged, and a processing system in communication with the image sensor, the method comprising the steps of: detecting an actuation signal for the wiping system; analyzing an image from the image sensor responsive to generation of the actuation signal; and generating an initial reference measurement of the spatial composition on the surface responsive to the analysis of the image.
Claim 30
Independent Claim
106 words
A method of detecting moisture on a surface, using a system including an image sensor, an optical system operative to focus at least a portion of the surface onto the image sensor, a wiping system operative to remove moisture from at least a portion of the surface imaged, and a processing system in communication with the image sensor, the method comprising the steps of: detecting an actuation signal for the wiping system; analyzing an image from the image sensor responsive to generation of the actuation signal; and generating an initial reference measurement of the spatial composition on the surface responsive to the analysis of the image.
Claim 31
Dependent Claim
24 words
The method of claim 28, further including the step of generating a new initial reference measurement following each actuation signal for the wiper system.
Claim 32
Dependent Claim
35 words
The method of claim 28, further including the step of subtracting the initial reference measurement from at least one future image to detect a change in the spatial composition on the surface due to moisture.
Claim 33
Dependent Claim
24 words
The method of claim 28, further including the step of comparing the initial measurement to later measurements to detect a change in spatial composition.
Claim 34
Dependent Claim
48 words
The method of claim 28, wherein the wiping system includes a wiper blade, and the method further including the step of detecting whether the wiper blade has passed through the at least a portion of the surface during a time period following generation of the wiper actuation signal.
Claim 35
Dependent Claim
44 words
The method of claim 28, further including the step of activating the defroster and deactivating the wiper system if the wiper blade has not passed through the at least a portion of the surface during a time period following generation of the actuation signal.
Claim 36
Dependent Claim
26 words
The method of claim 33, further including the step of determining if the outside temperature is within a freezing climate condition prior to actuating the defroster.
Claim 37
Dependent Claim
23 words
The method of claim 33, wherein the step of deactivating the wiper includes suspending operation of the wiper for a period of time.
Claim 38
Independent Claim
95 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image at least a portion of the surface onto the image sensor; and a processing system in communication with the image sensor and operative to analyze images from the image sensor to detect moisture, wherein the sensitivity of the image sensor during high ambient light conditions is reduced and the sensitivity of the image sensor during low ambient light conditions is increased whereby the image sensor has a variable sensitivity which is lower during high ambient light conditions.
Claim 39
Independent Claim
95 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image at least a portion of the surface onto the image sensor; and a processing system in communication with the image sensor and operative to analyze images from the image sensor to detect moisture, wherein the sensitivity of the image sensor during high ambient light conditions is reduced and the sensitivity of the image sensor during low ambient light conditions is increased whereby the image sensor has a variable sensitivity which is lower during high ambient light conditions.
Claim 40
Dependent Claim
14 words
The system of claim 36, wherein the image sensor includes an array of pixels.
Claim 41
Dependent Claim
24 words
The system of claim 37, wherein a measurement of the ambient light conditions is made using the value of pixels from a previous cycle.
Claim 42
Dependent Claim
31 words
The system of claim 38, wherein the measurement of the ambient light condition is the average gray scale value of at least a portion of the pixels in a previous cycle.
Claim 43
Dependent Claim
23 words
The system of claim 36, wherein the sensitivity of the image sensor is varied by changing the integration period for the image sensor.
Claim 44
Dependent Claim
21 words
The system of claim 36, wherein the image sensor images and the processing system processes a subwindow of the image sensor.
Claim 45
Dependent Claim
20 words
The system of claim 36, further including a supplemental illuminator for selectively illuminating at least a portion of the surface.
Claim 46
Dependent Claim
19 words
The system of claim 42, wherein the processing system turns on the supplemental illuminator during low ambient light conditions.
Claim 47
Dependent Claim
30 words
The system of claim 43, wherein the supplemental illuminator is turned on for a current cycle when a measured light level in a previous cycle is below a threshold value.
Claim 48
Dependent Claim
27 words
The system of claim 44, wherein the measured light level is the average pixel level of at least a portion of the array in a previous cycle.
Claim 49
Dependent Claim
14 words
The system of claim 42, wherein the supplemental illuminator produces light in visible wavelengths.
Claim 50
Dependent Claim
14 words
The system of claim 42, wherein the supplemental illuminator produces light in infrared wavelengths.
Claim 51
Independent Claim
77 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image at least a portion of the surface onto the image sensor; and a processing system in communication with the image sensor, the processing system operative to analyze images from the image sensor to detect moisture on at least a portion of the surface imaged, the processing system further operative to distinguish long term spatial components on the surface imaged.
Claim 52
Independent Claim
77 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image at least a portion of the surface onto the image sensor; and a processing system in communication with the image sensor, the processing system operative to analyze images from the image sensor to detect moisture on at least a portion of the surface imaged, the processing system further operative to distinguish long term spatial components on the surface imaged.
Claim 53
Dependent Claim
23 words
The system of claim 48, wherein the processing system determines the spatial components of the at least a portion of the surface imaged.
Claim 54
Dependent Claim
20 words
The system of claim 48, wherein the spatial composition is determined by analyzing the image for high spatial frequency components.
Claim 55
Dependent Claim
24 words
The system of claim 50, wherein said processing system subtracts long term high spatial frequency component measurements when analyzing an image to detect moisture.
Claim 56
Dependent Claim
21 words
The system of claim 48, wherein the spatial composition is determined by analyzing the image for sharp discontinuities caused by edges.
Claim 57
Dependent Claim
20 words
The system of claim 52, wherein said processing system subtracts long term discontinuities when analyzing an image to detect moisture.
Claim 58
Independent Claim
76 words
A system for detecting moisture on a surface comprising: an array image sensor including a plurality of pixels; an optical system operative to image a portion of the surface onto the array image sensor; and a processing system in communication with the array image sensor operative to analyze images from the array image sensor to detect moisture, wherein the processing system ignores pixels in the array image sensor having a gray scale value above a threshold.
Claim 59
Independent Claim
76 words
A system for detecting moisture on a surface comprising: an array image sensor including a plurality of pixels; an optical system operative to image a portion of the surface onto the array image sensor; and a processing system in communication with the array image sensor operative to analyze images from the array image sensor to detect moisture, wherein the processing system ignores pixels in the array image sensor having a gray scale value above a threshold.
Claim 60
Dependent Claim
20 words
The system of claim 54, wherein the processing system includes an analog-to-digital converter for converting pixel levels into digital signals.
Claim 61
Dependent Claim
16 words
The system of claim 55, wherein the threshold is the saturation level of the analog-to-digital converter.
Claim 62
Dependent Claim
18 words
The system of claim 55, wherein those pixels whose outputs cause saturation of the analog-to-digital converter are skipped.
Claim 63
Dependent Claim
37 words
The system of claim 54, wherein the processing system reduces the sensitivity of the image sensor during high ambient light conditions and the processing system increases the sensitivity of the image sensor during low ambient light conditions.
Claim 64
Dependent Claim
28 words
The system of claim 58, wherein an ambient light measurement is made as a function of the gray scale values of at least a portion of the pixels.
Claim 65
Dependent Claim
27 words
The system of claim 59, wherein the ambient light measurement is a function of the average gray scale value of at least a portion of the pixels.
Claim 66
Independent Claim
80 words
A system for detecting moisture on a surface comprising: an image sensor including a plurality of pixels; an optical system operative to image a portion of the surface onto the image sensor; and a processing system in communication with the image sensor operative to analyze images from the image sensor to detect moisture, wherein the processing system analyses a sub window of the image sensor more frequently than other portions of the image sensor in order to monitor a condition.
Claim 67
Independent Claim
80 words
A system for detecting moisture on a surface comprising: an image sensor including a plurality of pixels; an optical system operative to image a portion of the surface onto the image sensor; and a processing system in communication with the image sensor operative to analyze images from the image sensor to detect moisture, wherein the processing system analyses a sub window of the image sensor more frequently than other portions of the image sensor in order to monitor a condition.
Claim 68
Dependent Claim
25 words
The system of claim 61, further including a wiper system, wherein the condition monitored is removal of moisture following actuation of the moisture removal system.
Claim 69
Dependent Claim
26 words
The system of claim 61, wherein the condition monitored is passage of the wiper within a period of time following actuation of the moisture removal system.
Claim 70
Dependent Claim
26 words
The system of claim 61, wherein the processing system monitors the ratio of the vertical component of an image to the horizontal component of an image.
Claim 71
Dependent Claim
24 words
The system of claim 64, wherein the processing system detects the windshield wiper when the horizontal component is much greater than the vertical component.
Claim 72
Dependent Claim
47 words
The system of claim 61, wherein the processing system reduces the sensitivity at least a portion of the image sensor during high ambient light conditions and the processing system increases the sensitivity of the at least a portion of the image sensor during low ambient light conditions.
Claim 73
Dependent Claim
40 words
The system of claim 61, wherein the image sensor includes an array of pixels and the ambient light measurement is derived from the average gray scale value of at least a portion of the pixels measured in a previous cycle.
Claim 74
Independent Claim
64 words
A system for detecting moisture on a surface, comprising an image sensor imaging at least a portion of the surface, and a processing system coupled to the image sensor to analyze the image to detect moisture, wherein the image sensor has a sensitivity that is varied such that the sensitivity is reduced under high ambient light conditions and lengthened under low ambient light conditions.
Claim 75
Independent Claim
64 words
A system for detecting moisture on a surface, comprising an image sensor imaging at least a portion of the surface, and a processing system coupled to the image sensor to analyze the image to detect moisture, wherein the image sensor has a sensitivity that is varied such that the sensitivity is reduced under high ambient light conditions and lengthened under low ambient light conditions.
Claim 76
Dependent Claim
23 words
The system of claim 68, wherein the image sensor further includes an illuminator for selectively illuminating the surface viewed by the image sensor.
Claim 77
Dependent Claim
47 words
The system of claim 68, wherein the processing system is responsive to previous images from the image sensor to generate signals to reduce the sensitivity of the image sensor during high ambient light conditions and increase the sensitivity of the image sensor during low ambient light conditions.
Claim 78
Dependent Claim
28 words
The system of claim 68, wherein the image sensor includes an array of pixels and an ambient light measurement is made as a function of previous pixel measurements.
Claim 79
Dependent Claim
33 words
The system of claim 71, wherein the ambient light measurement is made as a function of the average gray scale value of at least a portion of the pixels in a previous image.
Claim 80
Independent Claim
77 words
A system for detecting moisture on a surface, comprising a low resolution image array sensor; an optical system operable to image a portion of the surface onto the image sensor, to focus objects at the surface onto the image sensor, and to blur objects away from the surface; and a processor in communication with the image sensor, the processor operative to detect the edges of moisture whereby a signal may be generated based on the edges detected.
Claim 81
Independent Claim
77 words
A system for detecting moisture on a surface, comprising a low resolution image array sensor; an optical system operable to image a portion of the surface onto the image sensor, to focus objects at the surface onto the image sensor, and to blur objects away from the surface; and a processor in communication with the image sensor, the processor operative to detect the edges of moisture whereby a signal may be generated based on the edges detected.
Claim 82
Dependent Claim
26 words
The system of claim 73, wherein the image array sensor has less than approximately 65 rows of pixels and less than approximately 65 columns of pixels.
Claim 83
Dependent Claim
13 words
The system of claim 74, wherein the pixels are approximately 40 μm pixels.
Claim 84
Dependent Claim
25 words
The system of claim 73, wherein the ratio of the number of pixels to the imaged area in square millimeters is approximately 4 to 1.
Claim 85
Dependent Claim
18 words
The system of claim 73, wherein the image array sensor has approximately 50 to 64 columns of pixels.
Claim 86
Dependent Claim
18 words
The system of claim 73, wherein the image array sensor has approximately 50 to 64 rows of pixels.
Claim 87
Independent Claim
102 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image a portion of the surface onto the image sensor; a wiper; and a processing system in communication with the image sensor and the wiper, the processing system selectively responsive to the image sensor for actuating the wiper and detecting whether the wiper has moved over at least a portion of the surface, the processing system outputting a control signal if the wiper does not move over the at least a portion of the surface within a certain time period following actuation of the wiper.
Claim 88
Independent Claim
102 words
A system for detecting moisture on a surface comprising: an image sensor; an optical system operative to image a portion of the surface onto the image sensor; a wiper; and a processing system in communication with the image sensor and the wiper, the processing system selectively responsive to the image sensor for actuating the wiper and detecting whether the wiper has moved over at least a portion of the surface, the processing system outputting a control signal if the wiper does not move over the at least a portion of the surface within a certain time period following actuation of the wiper.
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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) | 2003-08-01 | 2004-01-31 | 2004-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-01 | 2008-01-31 | 2008-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-01 | 2012-01-31 | 2012-08-01 | $7700.00 | Window Closed / Lapsed |