# Optical sensors

## System Definition - Goal and scope
### Definition

* Optical/image sensor = device that detects and converts light rays into electrical signals, that can be viewed, analyzed, or stored
* Context : In smartphones and cameras, the number of image sensors is increasing. No environmental data available

#### What is it used for?

They are used in phones, cars, laptops, tablets, industrial/medical systems, security cameras, cars and other vehicles, etc.

#### Are there different types/technologies?

Two main types :

* Charge-coupled device (CCD)
* Active-pixel sensor (CMOS sensor) -> cheaper, low electricity consumption. They are more used in modern cameras.
* IR sensor (for night vision)

CDDs' characteristics:

* Global shutter
* Low noise
* High dynamic range
* Medium range frame rates
* Subject to smearing

Moderm CMOS characteristics:

* Global shutter and rolling shutter models
* Low to very low noise
* High to very high dynamic range
* Very high frame rates
* No smearing

#### If different types, what are the differences in terms of materials, process, use consumption?

TBC

#### Is there a generic component that represents a family of components?

TBC

#### How many sub-parts does the system consist of?

The main parts of a CMOS image sensor are the following:

* Sensor chip (wafer)
* Wire bonds
* Package
* Cover glass
* Contact pads

Sources :

* [Blog post - Thinklucid](https://thinklucid.com/tech-briefs/understanding-digital-image-sensors/)
* [Blog post - Ansys](https://www.ansys.com/simulation-topics/what-is-cmos-image-sensor)


### Perimeter

#### What is included?
TBC
#### What is excluded?
TBC

### Functional unit and reference flows
#### What is the functional unit?
TBC
#### What are the reference flows?
TBC


## Life Cycle - Inventory
=> Goal: Define state of the art on life cycle stages to be considered.

### Database and tools
#### What are the already existing data (dataset, parametric model, paper, etc.)?
TBC

### Raw materials
=> Goal: List the technical information needed for the LCI.

#### What is it made of?
TBC
#### Who are the main mining? Where are they located?
TBC
#### Is there mining processes information available?
TBC
### Manufacturing
=> Goal: List the technical information needed for the LCI.

//For each system sub-part://
#### What are the manufacturing processes?
TBC
#### What are the assembly processes?
TBC
#### For each process, what is the energy consumption?
TBC
#### For each process, what are the inputs (water, chemicals, etc.) ?
TBC
#### For each process, what is the yield? Are they co-products and/or losses?
TBC

#### How the “main” manufacturers can be characterized: by the number of components manufactured, the market share (€), other?
TBC

#### Who are the main manufacturers? Where are they located?

* Sony corporation (Japan, Integrated Device Manufacturer (IDM))
* Samsung Electronics (South Korea, IDM)
* OmniVision Technologies (US, fabless)
* onsemi (US, IDM)
* STMicroelectronics (CH, IDM)

[Source](https://www.marketsandmarkets.com/ResearchInsight/image-sensor-semiconductor-market.asp#:~:text=Major%20Image%20Sensors%20companies%20include,Components%20Industries%2C%20LLC%20(US)



### Distribution and packaging
=> Goal: List the technical information needed for the LCI.

#### What are the packaging? Made of which materials?
TBC
#### Which are the transport modes?
TBC
#### What are the transport distances?
TBC

### Use
=> Goal: List the technical information needed for the LCI.

#### What is the service lifespan? (durée d'utilisation)
TBC
#### Is there a reparation factor?
TBC
#### Is there sub-parts replacement?
TBC

#### Where is it used?
TBC
#### Who are the users?
TBC
#### Which + how much energy does it need?
TBC
#### Is there emissions from use?
TBC

### End of life
=> Goal: List the technical information needed for the LCI.

#### What is the lifetime? (durée de vie)
TBC
#### Is it different from lifespan and why?
TBC
#### Is it refurbished? + Where?
TBC
#### Is it recyclable? Can it be dismantled? Which material can be separated? + Where and how?
TBC
#### Is it incinerated with energy recovery? Just incinerated? Buried? + Where?
TBC
#### Which part of waste can be considered as mismanaged (neither recycled, nor incinerated, nor buried)?
TBC


## Environmental assessment
=> Goal: Define state of the art on environmental impacts. 

### What are the impact assessment methods used (EF, ReCiPe, others)?
TBC
### What are the known environmental impacts associated to the system (indicators)?
TBC
### What are the known hotspots? Which raw material? Which life stage?

* CCD / CMOS
* Mono / color sensor
* Resolution → sensor size
* Pixel size → sensor size


### What are the potential parameters affecting environmental impacts?
TBC
### What are the main source of uncertainty?
TBC


## Bibliography
=> Goal: Source every data we cited previously

### List of our sources
TBC
### Data origin: bibliographic source / consortium hypothesis / expert opinion - required if a Data Quality Rating (DQR) must be completed
TBC


## Next steps
=> Goal: List challenges and clarify priority areas for action

### What do we know we don't know?
TBC
### What are the identified challenges?
TBC
### What paths/ideas should be explored?
TBC