US6507286B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Luminance control of automotive displays using an ambient light sensor
Assignee: Visteon Global Technologies Inc
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Filing: 2000-12-29
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Granted: 2003-01-14
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Expires: 2020-12-29
Abstract
Abstract According to the system and the method of the present invention, a display's visibility is maintained depending on lighting conditions that are sensed by an ambient light sensor ( 16 ). Logic ( 10 ) is applied to the output of the light sensor ( 16 ) and in conjunction with a headlight status indicator ( 14 ) to determine whether daytime (D) or nighttime (N) lighting condition exists and to determine a brightness level ( 18 ) to be commanded to the display. The logic ( 10 ) of the present invention maintains a visible display even in situations where a vehicle's headlights are active during daylight lighting conditions.
Inventors
- 👤 Paul F. L. Weindorf
- 👤 Gregory John Milne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:30
CPC Classifications
B; B60; B60Q; B60Q3/00; B60Q3/10; B60Q3/16; B60Q3/18; B60K; B60K2360/00; B60K2360/20; B60K2360/33; B60K2360/349
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
133 words
A method for maintaining visibility of a display in a vehicle's cockpit when the vehicle's headlights are turned on during daytime lighting conditions, said method comprising the steps of: determining a status of a lighting switch indicating a vehicle's headlight status detecting an ambient light level; determining lighting conditions based on said detected ambient light level; logically selecting a brightness level to be commanded to said display based on said vehicle's headlight status, said detected ambient light level, and said determined lighting conditions; overriding an automatic nighttime luminance control of said display; and applying said selected brightness level to said display increasing said brightness level of said display to an appropriate daytime brightness level for maintaining visibility of said display particularly during periods of daytime lighting conditions when said vehicle's headlights are active.
Claim 2
Independent Claim
133 words
A method for maintaining visibility of a display in a vehicle's cockpit when the vehicle's headlights are turned on during daytime lighting conditions, said method comprising the steps of: determining a status of a lighting switch indicating a vehicle's headlight status detecting an ambient light level; determining lighting conditions based on said detected ambient light level; logically selecting a brightness level to be commanded to said display based on said vehicle's headlight status, said detected ambient light level, and said determined lighting conditions; overriding an automatic nighttime luminance control of said display; and applying said selected brightness level to said display increasing said brightness level of said display to an appropriate daytime brightness level for maintaining visibility of said display particularly during periods of daytime lighting conditions when said vehicle's headlights are active.
Claim 3
Dependent Claim
30 words
The method as claimed in claim 1 further comprising the step of applying a time constant filter and hysteresis to said ambient light sensor output for determining nighttime versus daytime.
Claim 4
Dependent Claim
38 words
The method as claimed in claim 1 wherein said step of logically determining a brightness level to be commanded further comprises determining whether a manually selected brightness level is desired or an automatically selected brightness level is desired.
Claim 5
Dependent Claim
59 words
The method as claimed in claim 3 further comprising the steps of: selecting a predetermined brightness command from a source containing stored values for daytime and nighttime lighting conditions when a manual mode is selected; and selecting a predetermined brightness command from a source containing stored values for daytime and nighttime lighting conditions when an automatic mode is selected.
Claim 6
Dependent Claim
42 words
The method as claimed in claim 4 further comprising the step of applying a time constant filter to said step of selecting a predetermined brightness command in a daytime automatic mode for preventing objectionable switching of a brightness level of said display.
Claim 7
Dependent Claim
43 words
The method as claimed in claim 4 further comprising the step of applying a software filter algorithm to said step of selecting a predetermined brightness command in a daytime automatic mode to control a speed of transition between brightness levels of said display.
Claim 8
Dependent Claim
73 words
The method as claimed in claim 4 further comprising the steps of: applying a time constant filter to said step of selecting a predetermined brightness command in an automatic mode for preventing objectionable switching of a brightness level of said display; and applying a software filter algorithm to said step of selecting a predetermined brightness command in a daytime automatic mode to control a speed of transition between brightness levels of said display.
Claim 9
Dependent Claim
33 words
The method as claimed in claim 1 further comprising the step of selecting a predetermined brightness command only from a source containing stored values for daytime lighting conditions when said headlights are inactive.
Claim 10
Dependent Claim
34 words
The method as claimed in claim 1 wherein said step of logically selecting a brightness level further comprises selecting a brightness level based on an instrument lighting control setting during an automatic nighttime mode.
Claim 11
Independent Claim
100 words
A system for maintaining visibility of a display in a vehicle's cockpit when the vehicle's headlights are turned on during daytime lighting conditions and an automatic nighttime luminance control is activated, said system comprising: an ambient light sensor having an output; a switch having an output that indicates a status of the vehicle's headlights; and an algorithm using said ambient light sensor output and said headlight status to logically determine a brightness level to be commanded to the display by overriding the automatic nighttime luminance control and increasing a brightness level of the display to said logically determined brightness level.
Claim 12
Independent Claim
100 words
A system for maintaining visibility of a display in a vehicle's cockpit when the vehicle's headlights are turned on during daytime lighting conditions and an automatic nighttime luminance control is activated, said system comprising: an ambient light sensor having an output; a switch having an output that indicates a status of the vehicle's headlights; and an algorithm using said ambient light sensor output and said headlight status to logically determine a brightness level to be commanded to the display by overriding the automatic nighttime luminance control and increasing a brightness level of the display to said logically determined brightness level.
Claim 13
Dependent Claim
28 words
The system as claimed in claim 10 further comprising a filter applied to said ambient light sensor output for determining a rate of transition between display brightness levels.
Claim 14
Dependent Claim
27 words
The system as claimed in claim 11 wherein said filter further comprises a time delay for controlling a transition from daytime lighting conditions to nighttime lighting conditions.
Claim 15
Dependent Claim
24 words
The system as claimed in claim 10 further comprising a night-to-day hysteresis for controlling a transition from nighttime lighting conditions to daytime lighting conditions.
Claim 16
Dependent Claim
49 words
The system as claimed in claim 13 wherein said night-to-day hysteresis further comprises: a nighttime threshold brightness level; a daytime threshold brightness level; and a predetermined value said ambient light sensor output must increase over said nighttime threshold level to transition from nighttime lighting conditions to daytime lighting conditions.
Claim 17
Dependent Claim
65 words
The system as claimed in claim 14 further comprising: a predetermined value said ambient light sensor output must decrease below said nighttime threshold brightness for determining a transition from daytime to nighttime lighting conditions: and wherein said predetermined value for determining a transition from nighttime to daytime lighting conditions is greater than said predetermined value for determining a transition from daytime to nighttime lighting conditions.
Claim 18
Dependent Claim
16 words
The system as claimed in claim 10 wherein said ambient light sensor is a logarithmic sensor.
Claim 19
Dependent Claim
25 words
The system as claimed in claim 10 further comprising a switch for selecting between a manual and an automatic mode of operation for said system.
Claim 20
Dependent Claim
32 words
The system as claimed in claim 17 wherein said algorithm uses a manual brightness determination look up table to determine said brightness level to be commanded for said manual mode of operation.
Claim 21
Dependent Claim
31 words
The system as claimed in claim 17 wherein said algorithm uses an automatic brightness control scheme to determine a brightness level to be commanded to said display for an automatic mode.
Claim 22
Dependent Claim
48 words
The system as claimed in claim 10 wherein said algorithm logically determines a daytime brightness level to be commanded to said display when said switch indicates active headlights and said ambient light sensor indicates daytime lighting conditions in order to avoid an objectionable brightness level for said display.
Claim 23
Dependent Claim
29 words
The system as claimed in claim 10 wherein said algorithm logically determines a nighttime brightness level to be commanded to said display based on an instrument lighting control setting.
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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) | 2006-01-13 | 2006-07-15 | 2007-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-01-13 | 2010-07-15 | 2011-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-01-13 | 2014-07-15 | 2015-01-14 | $7700.00 | Window Closed / Lapsed |