Quality Control
We are actively taking measures to improve product quality levels.


Why Hamamatsu?


Our company

( )

Select your region and country.

HPK_08_Auto air con-kv_xx

Automatic air conditioner

Automatic air conditioner is a function that automatically controls the air conditioner, based on the temperature inside the car and the amount of sunlight. It uses a sunlight sensor with built-in photodiode to detect the amount of sunlight.
In recent years, automatic air conditioner has become a standard feature installed in automobiles, and it is rapidly achieving greater sophistication, with features such as “left and right independent controls”. Because of this, it has become necessary to make the installed sunlight sensors capable of not only detecting the amount of sunlight, but also the position of the sun.
It is also necessary to make sunlight sensors more compact and integrated with other sensors that monitor external environment such as raindrop detectors and light and dark detectors, with consideration for the interior design of vehicles when increasing the number of sensors installed in them. Hamamatsu can also provide optical semiconductor devices with custom specifications that meet such requirements.

Mechanism of the automatic air conditioner (application of sunlight sensors)

Si photodiodes are used in sunlight sensors installed in automobiles. It controls the air conditioner by outputting a current according to the amount of sunlight.

Recommended products

Sunlight sensor (photodiode assembly)

■ Features
・Wide photosensitive area
・Wide temperature range, high reliability
・Low price



This is a sunlight sensor with an integrated connector. It comes equipped with a wide directivity cover suitable for on-board automatic air conditioner sunlight sensors.




Photosensors for sunlight sensors


Si photodiode S9674

This Si photodiode comes in a glass epoxy package applicable to lead-free solder reflow. It features a wide operating and storage temperature range. Photosensitive area: 2 × 2 mm.


Si photodiode S9981-01CT

This Si photodiode comes in a glass epoxy package applicable to lead-free solder reflow. It features a wide operating and storage temperature range (-40 to +125 ℃). Photosensitive area: 1.3 × 1.3 mm.


4-segment Si PIN photodiode S5981

This 4-segment photodiode comes in a ceramic package. Photosensitive area: 10 × 10 mm.


Si PIN photodiode S14016-01DT

This surface mount type Si PIN photodiode comes in a plastic package. Photosensitive area: 1.8 × 2.1 mm.

IC technology

We incorporate a photodiode and peripheral circuit into a single package and converted to IC, so it can contribute to reducing the number of parts and mounting space. We also offer custom support for this type of specification.

Contact us for more information.

  • Literature
  • Price
  • Delivery
  • Custom order
  • Support
  • Other

Contact us