Brückner, Stefan ; Trinh, Quang Vinh ; Khanh, Tran Quoc (2011)
Double-binned LEDs reduce inhomogeneity in rearlamps?
In: 9th International Symposium on Automotive Lighting
Book Section, Bibliographie
Abstract
When developing automotive rearlamps employing multiple LEDs manufacturers face inhomogeneity problems. Realizing brake and taillight with the same LEDs introduces the need of dimming these LEDs. Widely used dimming methods are Pulse Width Modulation (PWM) and Constant Current Reduction (CCR). CCR has several advantages over PWM, including flicker-free operation and energy efficiency. On the downside, CCR can cause inhomogeneity in rearlamps, at least in combination with traditional single binned LEDs. Recently introduced double-binned LEDs are selected (binned) at two different forward currents, according to brake and taillight level. Thus, the perceived inhomogeneity could be reduced.
In our Lab we measured a number of double binned red rearlamp LEDs. For comparison reasons, we also measured single binned LEDs of the same type. We present an analysis of the results, giving answers if the spread in luminous flux or dominant wavelength changes with forward current or temperature, and if these changes lead to drop out of the ECE color range or if they are noticeable by the human eye.
| Item Type: | Book Section |
|---|---|
| Erschienen: | 2011 |
| Creators: | Brückner, Stefan ; Trinh, Quang Vinh ; Khanh, Tran Quoc |
| Type of entry: | Bibliographie |
| Title: | Double-binned LEDs reduce inhomogeneity in rearlamps? |
| Language: | English |
| Date: | September 2011 |
| Place of Publication: | Darmstadt |
| Book Title: | 9th International Symposium on Automotive Lighting |
| Abstract: | When developing automotive rearlamps employing multiple LEDs manufacturers face inhomogeneity problems. Realizing brake and taillight with the same LEDs introduces the need of dimming these LEDs. Widely used dimming methods are Pulse Width Modulation (PWM) and Constant Current Reduction (CCR). CCR has several advantages over PWM, including flicker-free operation and energy efficiency. On the downside, CCR can cause inhomogeneity in rearlamps, at least in combination with traditional single binned LEDs. Recently introduced double-binned LEDs are selected (binned) at two different forward currents, according to brake and taillight level. Thus, the perceived inhomogeneity could be reduced. In our Lab we measured a number of double binned red rearlamp LEDs. For comparison reasons, we also measured single binned LEDs of the same type. We present an analysis of the results, giving answers if the spread in luminous flux or dominant wavelength changes with forward current or temperature, and if these changes lead to drop out of the ECE color range or if they are noticeable by the human eye. |
| Uncontrolled Keywords: | LED, rearlamps |
| Divisions: | 18 Department of Electrical Engineering and Information Technology 18 Department of Electrical Engineering and Information Technology > Institute for Electromechanical Design (dissolved 18.12.2018) 18 Department of Electrical Engineering and Information Technology > Light Technology (from Oct. 2021 renamed "Adaptive Lighting Systems and Visual Processing") |
| Date Deposited: | 19 Jan 2012 13:05 |
| Last Modified: | 23 May 2024 10:48 |
| PPN: | |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Send an inquiry |
Options (only for editors)
 |
Show editorial Details |
Drucken
Impressum