EMC-Optimized Transparency: Reducing Electromagnetic Emissions in Surveillance Camera Domes
(2023) BMEM05 20231Department of Biomedical Engineering
- Abstract
- Electromagnetic compatibility (EMC) is a crucial aspect to product development. Companies need to make sure their products live up to the standards that exists around the world. One way of reducing electromagnetic emissions is to shield the product, using some conducting material, for instance, copper. An issue arises, though, when transparency is needed, like it is for cameras. At Axis Communications some cameras require a large aperture in its chassis, which increases emissions. This thesis aims to find solutions for transparent shielding of cameras with a dome-surface. This was done by creating prototype shields of different materials. The materials tested are an indium tin oxide film, a silver film, a galvanized steel wire mesh and an... (More)
- Electromagnetic compatibility (EMC) is a crucial aspect to product development. Companies need to make sure their products live up to the standards that exists around the world. One way of reducing electromagnetic emissions is to shield the product, using some conducting material, for instance, copper. An issue arises, though, when transparency is needed, like it is for cameras. At Axis Communications some cameras require a large aperture in its chassis, which increases emissions. This thesis aims to find solutions for transparent shielding of cameras with a dome-surface. This was done by creating prototype shields of different materials. The materials tested are an indium tin oxide film, a silver film, a galvanized steel wire mesh and an aluminium wire mesh. Shielding using aluminium foil with an aperture around the camera lens was also tested.
These prototypes were then evaluated based on reduction of emissions, while taking image quality and cost into account. The electromagnetic emissions were measured both from a comb generator circuit and an Axis camera. A comb generator is a harmonic signal generator that served as a consistent noise source. The measurements were made with near field probes and in an EMC chamber.
The results show that the prototypes manage to reduce emissions across a spectrum, some better than others, using both the comb generator and camera. The materials had varying transparencies, with some being indistinguishable with a regular camera lens. However, all prototypes, except for the aluminium foil with an aperture, had problems with infrared light. Thus, more research is needed before the materials can be implemented on real products. (Less) - Popular Abstract
- Transparent Shielding for Fixed Dome Cameras
Through rigorous testing with materials that are both transparent and conductive. We have been able to reduce emissions from a camera dome while keeping transparency.
As technology advances in both complexity and volume. It becomes more and more crucial to make sure that devices do not interfere electrically with each other. Therefore, a large chunk of product development is delegated to making sure that the devices satisfy the directives of the relevant markets. Imagine this: you’re working on the latest fixed dome camera at Axis and you bump into a problem. The camera is really noisy! Since the camera needs to have a large hole to be able to see, the fix is to spend a lot of time... (More) - Transparent Shielding for Fixed Dome Cameras
Through rigorous testing with materials that are both transparent and conductive. We have been able to reduce emissions from a camera dome while keeping transparency.
As technology advances in both complexity and volume. It becomes more and more crucial to make sure that devices do not interfere electrically with each other. Therefore, a large chunk of product development is delegated to making sure that the devices satisfy the directives of the relevant markets. Imagine this: you’re working on the latest fixed dome camera at Axis and you bump into a problem. The camera is really noisy! Since the camera needs to have a large hole to be able to see, the fix is to spend a lot of time troubleshooting the circuit board. But now instead, a “quick fix” could be to simply shielding using a transparent material and see an instant reduction of emissions.
The plan was to construct prototypes of different transparent materials and then testing emissions and image quality for evaluations. These prototypes can be seen as the camera’s own little ozone layer. Protecting the camera from BAD emissions, just like how the ozone layer protects Earth from ultra violet light
To test the emissions a circuit that generated noise was constructed to serve as a main noise source, but a camera was also used. The results point to a broad reduction of emissions using all prototypes, especially with the noise generator. The camera had some uncertainties, but the materials still managed to show potential!
Some of the prototypes has great clarity in the visible spectrum. But oh no! A problem occurs when using infrared light, which is used for lighting up dark areas. The infrared light LEDs bounces back from the prototypes and destroys the image quality. From both the aluminium mesh and silver film nothing could be seen, because of the small aperture size on the mesh and the reflections from the silver. The ITO had a greater shot at reflections, the image in front of the camera was visible with minor reflections. For the galvanized steel mesh the image quality was the best because of its larger aperture size. Still the mesh hid some image information for the camera. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9129304
- author
- Sondh, Fabian LU and Hansson, Erik LU
- supervisor
- organization
- alternative title
- EMC-optimerad transparens: Minskad elektromagnetisk strålning i kupoler för övervakningskameror
- course
- BMEM05 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- additional info
- 2023-08
- id
- 9129304
- date added to LUP
- 2023-06-26 10:59:25
- date last changed
- 2023-06-26 10:59:25
@misc{9129304,
abstract = {{Electromagnetic compatibility (EMC) is a crucial aspect to product development. Companies need to make sure their products live up to the standards that exists around the world. One way of reducing electromagnetic emissions is to shield the product, using some conducting material, for instance, copper. An issue arises, though, when transparency is needed, like it is for cameras. At Axis Communications some cameras require a large aperture in its chassis, which increases emissions. This thesis aims to find solutions for transparent shielding of cameras with a dome-surface. This was done by creating prototype shields of different materials. The materials tested are an indium tin oxide film, a silver film, a galvanized steel wire mesh and an aluminium wire mesh. Shielding using aluminium foil with an aperture around the camera lens was also tested.
These prototypes were then evaluated based on reduction of emissions, while taking image quality and cost into account. The electromagnetic emissions were measured both from a comb generator circuit and an Axis camera. A comb generator is a harmonic signal generator that served as a consistent noise source. The measurements were made with near field probes and in an EMC chamber.
The results show that the prototypes manage to reduce emissions across a spectrum, some better than others, using both the comb generator and camera. The materials had varying transparencies, with some being indistinguishable with a regular camera lens. However, all prototypes, except for the aluminium foil with an aperture, had problems with infrared light. Thus, more research is needed before the materials can be implemented on real products.}},
author = {{Sondh, Fabian and Hansson, Erik}},
language = {{eng}},
note = {{Student Paper}},
title = {{EMC-Optimized Transparency: Reducing Electromagnetic Emissions in Surveillance Camera Domes}},
year = {{2023}},
}