Cutting length adjustment mechanism, adjustment drive and hair cutting appliance

A cutting length adjustment mechanism for a hair cutting appliance, comprising:

• a movable portion movable with respect to a housing portion of the hair cutting appliance;
• and
• an adjustment drive comprising:
• an actuator configured to have both of a standard mode or a cutting length adjustment mode, wherein in the cutting length adjustment mode, the actuator is configured to actuate said movable portion of the cutting length adjustment mechanism with respect to said housing portion of the hair cutting appliance,
• a movement sensor unit configured to:
• detect a movement of the hair cutting appliance, said movement of the hair cutting appliance comprising at least one of:
• an orientation change and a position change:
• determine an adjustment control signal based on a rate of change and direction of said detected movement of said hair cutting appliance;
• and
• output said adjustment control signal derived from the detected movement,
• wherein in the standard mode involving a cutting action, the actuator is deactivated;
• wherein, in the cutting length adjustment mode, the actuator is operated on the basis of the adjustment control signal, and
• wherein when the movement sensor detects at least one of:
• a forward rotation of the hair cutting appliance;
• a rearward rotation of the hair cutting appliance;
• a speed of rotation of the hair cutting appliance;
• and a rotation angle of the hair cutting appliance, and the actuator is operating in the cutting length adjustment mode, the adjustment control signal causes a length adjustment of the cutting length adjustment mechanism.

A method of operating a cutting length adjustment mechanism for a hair cutting appliance, the method comprising acts of:

• providing an adjustment drive comprising an actuator for actuating a movable portion of the cutting length adjustment mechanism,
• providing a movement sensor configured to detect a movement of the hair cutting appliance, involving at least one of an orientation change and a position change,
• providing both of a standard mode, wherein a movement of the hair cutting appliance occurs while cutting hair without producing a corresponding change in a cutting length of the hair cutting appliance, or a cutting length adjustment mode, wherein the movement of the hair cutting appliance is provided for producing the corresponding change in the cutting length, wherein during the cutting length adjustment mode, the method comprising acts of:
• detecting a movement of the hair cutting appliance;
• determining an adjustment control signal based on at least one of a rate of change and a direction of said detected movement of said hair cutting appliance;
• operating the actuator to change the cutting length of the hair cutting appliance based on the adjustment control signal,
• wherein when the movement of the hair cutting appliance is at least one of a forward rotation of the hair cutting appliance;
• a rearward rotation of the hair cutting appliance;
• a speed of rotation of the hair cutting appliance;
• and a rotation angle of the hair cutting appliance, and the actuator is operating in the length adjustment mode, the adjustment control signal causing a length adjustment of the cutting length adjustment mechanism.