Abstract
Light-emitting diodes (LEDs) have been recognized as a generation of new light sources because they possess the properties of energy-saving, environmental protection, long lifetime, and those lacking in conventional lighting. To satisfy the requirements for different applications (e.g., for large-scale displays), determining the spatial radiances of LEDs is important to identifying their viewing angle and utilizing their lighting efficiency. The objective of this paper is to build up a real-time spatial radiance measurement system for LEDs, on the basis of digital signal processing (DSP) techniques. In this paper, the system analysis is given to show the feasibility of this work. Two primary subsystems are devised to perform the real-time measurements. First, in the optoelectronic sensing and signal processing subsystem, a wide-bandwidth photodiode sensing circuit is employed to acquire optical signals at a high speed, and an automatic gain control (AGC) circuit is designed to increase the measurement range. To support high-speed data processing, a DSP-based platform is developed in the subsystem. Second, a light-source rotation scheme is used in the optomechanical subsystem. For performance evaluations, we adopt a standard calibrating light source to test and verify our system. Experimental results indicate that the proposed system gives satisfactory results.
| Original language | English |
|---|---|
| Title of host publication | Light-Emitting Diodes |
| Subtitle of host publication | Research, Manufacturing, and Applications XI |
| DOIs | |
| Publication status | Published - 2007 May 25 |
| Event | Light-Emitting Diodes: Research, Manufacturing, and Applications XI - San Jose, CA, United States Duration: 2007 Jan 24 → 2007 Jan 25 |
Publication series
| Name | Proceedings of SPIE - The International Society for Optical Engineering |
|---|---|
| Volume | 6486 |
| ISSN (Print) | 0277-786X |
Other
| Other | Light-Emitting Diodes: Research, Manufacturing, and Applications XI |
|---|---|
| Country | United States |
| City | San Jose, CA |
| Period | 07/1/24 → 07/1/25 |
Fingerprint
Keywords
- LED
- Real-time measurement
- Spatial radiance
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering
Cite this
Design and implementation of real-time LED spatial radiance measurement systems. / Chang, Gao-Wei; Yeh, Zong-Mu; Liao, Chia Cheng.
Light-Emitting Diodes: Research, Manufacturing, and Applications XI. 2007. 64860K (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6486).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Design and implementation of real-time LED spatial radiance measurement systems
AU - Chang, Gao-Wei
AU - Yeh, Zong-Mu
AU - Liao, Chia Cheng
PY - 2007/5/25
Y1 - 2007/5/25
N2 - Light-emitting diodes (LEDs) have been recognized as a generation of new light sources because they possess the properties of energy-saving, environmental protection, long lifetime, and those lacking in conventional lighting. To satisfy the requirements for different applications (e.g., for large-scale displays), determining the spatial radiances of LEDs is important to identifying their viewing angle and utilizing their lighting efficiency. The objective of this paper is to build up a real-time spatial radiance measurement system for LEDs, on the basis of digital signal processing (DSP) techniques. In this paper, the system analysis is given to show the feasibility of this work. Two primary subsystems are devised to perform the real-time measurements. First, in the optoelectronic sensing and signal processing subsystem, a wide-bandwidth photodiode sensing circuit is employed to acquire optical signals at a high speed, and an automatic gain control (AGC) circuit is designed to increase the measurement range. To support high-speed data processing, a DSP-based platform is developed in the subsystem. Second, a light-source rotation scheme is used in the optomechanical subsystem. For performance evaluations, we adopt a standard calibrating light source to test and verify our system. Experimental results indicate that the proposed system gives satisfactory results.
AB - Light-emitting diodes (LEDs) have been recognized as a generation of new light sources because they possess the properties of energy-saving, environmental protection, long lifetime, and those lacking in conventional lighting. To satisfy the requirements for different applications (e.g., for large-scale displays), determining the spatial radiances of LEDs is important to identifying their viewing angle and utilizing their lighting efficiency. The objective of this paper is to build up a real-time spatial radiance measurement system for LEDs, on the basis of digital signal processing (DSP) techniques. In this paper, the system analysis is given to show the feasibility of this work. Two primary subsystems are devised to perform the real-time measurements. First, in the optoelectronic sensing and signal processing subsystem, a wide-bandwidth photodiode sensing circuit is employed to acquire optical signals at a high speed, and an automatic gain control (AGC) circuit is designed to increase the measurement range. To support high-speed data processing, a DSP-based platform is developed in the subsystem. Second, a light-source rotation scheme is used in the optomechanical subsystem. For performance evaluations, we adopt a standard calibrating light source to test and verify our system. Experimental results indicate that the proposed system gives satisfactory results.
KW - LED
KW - Real-time measurement
KW - Spatial radiance
UR - http://www.scopus.com/inward/record.url?scp=34249057166&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34249057166&partnerID=8YFLogxK
U2 - 10.1117/12.701665
DO - 10.1117/12.701665
M3 - Conference contribution
AN - SCOPUS:34249057166
SN - 0819465992
SN - 9780819465993
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Light-Emitting Diodes
ER -