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Optimized Day/Night Filter Mechanism

Håkansson, Anna LU and Carlson, Lisa LU (2014) MMK820 20141
Innovation
Abstract
This report is a result of a Master Thesis project made by Anna Håkansson and Lisa Carlson, two students from Mechanical Engineering with the specialization Product Development. The project was made at Axis Communications AB at the Department of Mechanics in interaction with the Division Machine Design at the Department of Design Science, Faculty of Engineering (LTH), Lund University.

Axis Communications AB is based in Lund, Sweden, and the company focuses on network and surveillance video cameras. Axis is currently a market leader within network video with customers worldwide and their intention is to keep expanding their business in the future and to keep deliver new, safe and reliable solutions in order to maintain their leading... (More)
This report is a result of a Master Thesis project made by Anna Håkansson and Lisa Carlson, two students from Mechanical Engineering with the specialization Product Development. The project was made at Axis Communications AB at the Department of Mechanics in interaction with the Division Machine Design at the Department of Design Science, Faculty of Engineering (LTH), Lund University.

Axis Communications AB is based in Lund, Sweden, and the company focuses on network and surveillance video cameras. Axis is currently a market leader within network video with customers worldwide and their intention is to keep expanding their business in the future and to keep deliver new, safe and reliable solutions in order to maintain their leading position on the market.

This project was started due to several issues regarding an IR-cut filter, also called Day/ Night filter, which is used in most of Axis’ cameras. Depending on the surrounding light, the device can switch between two modes in order to change the range of wavelengths that reaches the sensor. Since infrared radiation can impair the image quality, this mechanism makes it possible to acquire qualitative images independent of environmental circumstances.

The aim was to improve a current IR-cut filter that was designed for a specific fixed dome camera without changing the outer design of the camera. It was also desired to further investigate a pre-study of an auto back focus mechanism. Back focus is used to do fine adjustments regarding focus after having the camera installed. Axis have different techniques to adjust back focus, but this was a new solution and it was interesting to investigate if a combination of an IR-cut filter and the back focus mechanism was possible, in order to optimize costs and size. A prototype of the most promising solution should be made in order to prove the concept.

By identifying the requirements of the IR-cut filter and study various competitor solutions available on the market, a deeper knowledge and understanding of the mechanism was achieved. Primary concepts with different characteristics were generated and later evaluated regarding earlier identified requirements. Concepts with estimated potential were further developed after passing the first evaluation. Eventually the concepts ended up in one final concept. However, two different alternatives of the final concept were made as proof-of-concept prototypes and tested in order to ensure what alternative that was most technically feasible before future work.

The final design was called The Fan and consisted of a filter holder, which was attached to a shaft passing through the printed circuit board (PCB). The shaft was connected to a step motor, which was glued on the heat sink. A plug was designed in order to prevent light and dust inlet from where the device was inserted. (Less)
Please use this url to cite or link to this publication:
author
Håkansson, Anna LU and Carlson, Lisa LU
supervisor
organization
alternative title
Optimerad Dag/Natt-filter Mekanism
course
MMK820 20141
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Surveillance camera, IR-cut filter, Day/Night filter, Product development, Concept development, Engineering design, Mechanics
other publication id
ISRN LUTMDN/TMKT 14/5493 SE
language
English
id
4465579
date added to LUP
2014-06-13 16:10:39
date last changed
2014-06-13 16:10:39
@misc{4465579,
  abstract     = {{This report is a result of a Master Thesis project made by Anna Håkansson and Lisa Carlson, two students from Mechanical Engineering with the specialization Product Development. The project was made at Axis Communications AB at the Department of Mechanics in interaction with the Division Machine Design at the Department of Design Science, Faculty of Engineering (LTH), Lund University.

Axis Communications AB is based in Lund, Sweden, and the company focuses on network and surveillance video cameras. Axis is currently a market leader within network video with customers worldwide and their intention is to keep expanding their business in the future and to keep deliver new, safe and reliable solutions in order to maintain their leading position on the market.

This project was started due to several issues regarding an IR-cut filter, also called Day/ Night filter, which is used in most of Axis’ cameras. Depending on the surrounding light, the device can switch between two modes in order to change the range of wavelengths that reaches the sensor. Since infrared radiation can impair the image quality, this mechanism makes it possible to acquire qualitative images independent of environmental circumstances.

The aim was to improve a current IR-cut filter that was designed for a specific fixed dome camera without changing the outer design of the camera. It was also desired to further investigate a pre-study of an auto back focus mechanism. Back focus is used to do fine adjustments regarding focus after having the camera installed. Axis have different techniques to adjust back focus, but this was a new solution and it was interesting to investigate if a combination of an IR-cut filter and the back focus mechanism was possible, in order to optimize costs and size. A prototype of the most promising solution should be made in order to prove the concept.

By identifying the requirements of the IR-cut filter and study various competitor solutions available on the market, a deeper knowledge and understanding of the mechanism was achieved. Primary concepts with different characteristics were generated and later evaluated regarding earlier identified requirements. Concepts with estimated potential were further developed after passing the first evaluation. Eventually the concepts ended up in one final concept. However, two different alternatives of the final concept were made as proof-of-concept prototypes and tested in order to ensure what alternative that was most technically feasible before future work.

The final design was called The Fan and consisted of a filter holder, which was attached to a shaft passing through the printed circuit board (PCB). The shaft was connected to a step motor, which was glued on the heat sink. A plug was designed in order to prevent light and dust inlet from where the device was inserted.}},
  author       = {{Håkansson, Anna and Carlson, Lisa}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Optimized Day/Night Filter Mechanism}},
  year         = {{2014}},
}