Presence sensing method, presence sensing device and light system

A presence sensing device for a light, comprising:

• a sensing module, configured to detect a presence of a user with a first sensitivity while the light is off, and detect actions of the user with a second sensitivity higher than the first sensitivity while the light is on;
• and
• a controller, coupled with the sensing module and configured to:
• turn on the light if the sensing module identifies the presence of the user while the light is off and set a preset length for a delay time period during which the light is on,
• determine a length of a next delay time period based on the actions of the user during the previous delay time period immediately prior to the next delay time period, and
• set the delay time period as the determined length.

A light system, comprising:

• a light;
• and
• a presence sensing device coupled with the light, the presence sensing device comprising:
• a sensing module, configured to detect a presence of a user with a first sensitivity while the light is off, and detect actions of the user with a second sensitivity higher than the first sensitivity while the light is on, and
• a controller, coupled with the sensing module and configured to:
• turn on the light if the sensing module identifies the presence of the user while the light is off and set a preset length for a delay time period during which the light is on,
• determine a length of a next delay time period based on the actions of the user during the previous delay time period immediately prior to the next delay time period, and
• set the delay time period as the determined length.