Fn (Function) Key and Layer Types
HHKB Studio has four layers for each profile. Associating each function key ([Fn] (Fn1) to [Fn3]) with each layer allows you to assign several operations to a single physical key.
Fn (Function) key type
In HHKB Studio, you can switch layers using the [Fn] (Fn1) to [Fn3] keys.
By default, the [Fn] (Fn1) key and [Fn2] key are assigned to the keys as shown below.
![Position of [Fn] (Fn1) and [Fn2] Keys](../common/../images/fn1fn2_US.png)
The [Fn3] key is not assigned. For details, refer to "Layer type" below.
Layer type
You can use the following four layers differently for each profile.
- Standard layer
This layer can be used when none of the [Fn] (Fn1) to [Fn3] keys are pressed.
- Fn1 layer
This layer can be used when the [Fn] (Fn1) key is pressed.
By default, the operations printed on the front side of the key tops, such as F1 to F12, PgUp (Page Up), Caps, and the arrow keys (cursor) are assigned. For details, refer to Inputting Characters on the Front Side of Key Tops.
The [Fn] (Fn1) key is assigned to a key on the keyboard labeled as "Fn".
- Fn2 layer
This layer can be used when the [Fn2] key is pressed.
By default, the operations to change the movements of the pointing stick and gesture pads are assigned. For details, refer to the following sections.
The [Fn2] key is assigned to the mouse key center button.
- Fn3 layer
You can assign a new key to the Fn3 layer by assigning the [Fn3] key that is not set by default to a desired key using Keymap Tool.
Using Keymap Tool, you can also change the operations for assigning to each layer, change the positions of the [Fn] (Fn1) and [Fn2] keys, and assign the [Fn3] key to a desired key.