Hairstyling device

1 . A hairstyling device comprising:

a heatable hair contact member having a hair-contactable surface, the hair contact member being operable to apply heat to a tress of hair of a user via the hair-contactable surface by movement of the hair contact member along the tress of hair between a first end of the tress and a second end of the tress;

sensor equipment configured to generate a sensor output dependent on movement of the hair contact member; and

a controller configured to:

determine, based on the sensor output, that the hair contact member is moving along the tress from a first end of the tress towards a second end of the tress, comprising determining a displacement of the hair contact member from the first end of the tress; and

based on the determining, control heating of the hair contact member to cause the operating temperature of the hair contact member to change as the hair contact member moves along the tress from the first end of the tress towards the second end of the tress, comprising controlling heating of the hair contact member based on the determined displacement.

2 . The hairstyling device according to claim 1 ,

wherein the first end of the tress comprises a hair-root end of the tress, and

wherein the second end of the tress comprises a hair-tip end of the tress.

3 . The hairstyling device according to claim 2 , wherein the controller is configured to cause the operating temperature of the hair contact member to increase as the hair contact member moves along the tress from the hair-root end of the tress towards the hair-tip end of the tress.

4 . The hairstyling device according to claim 1 ,

wherein the controller is configured to control heating of the hair contact member based on a predetermined threshold operating temperature of the hair contact member, and

wherein the predetermined threshold operating temperature is dependent on the determined displacement of the hair contact member from the first end of the tress.

5 . The hairstyling device according to claim 1 , wherein the controller is configured to:

determine, based on the sensor output, a speed of the hair contact member; and

control heating of the hair contact member based on the determined speed.

6 . The hairstyling device according to claim 5 , wherein the controller is configured to cause the operating temperature of the hair contact member to increase at a rate dependent on the determined speed.

7 . The hairstyling device according to claim 1 , wherein the sensor equipment comprises an inertial measurement unit, IMU.

8 . The hairstyling device according to claim 1 , wherein the sensor equipment comprises a Hall effect sensor.

9 . The hairstyling device according to claim 1 , wherein the controller is configured to process the sensor output using a velocity and/or position estimation algorithm.

10 . The hairstyling device according to claim 9 , wherein the velocity and/or position estimation algorithm comprises a Madgwick filter.

11 . The hairstyling device according to claim 1 , wherein causing the operating temperature to change comprises adjusting an amount of energy used to heat the hair contact member as the hair contact member moves along the tress from the first end of the tress towards the second end of the tress.

12 . The hairstyling device according to claim 1 , wherein the controller is configured to cause the operating temperature of the hair contact member to increase at a predetermined rate as the hair contact member moves along the tress from the first end towards the second end.

13 . The hairstyling device according to claim 1 , wherein the controller is configured to cause the operating temperature of the hair contact member when the hair contact member is at the second end to be between 40 and 80 degrees higher than the operating temperature of the hair contact member when the hair contact member is at the first end.

14 . The hairstyling device according to claim 1 , wherein the controller is configured to:

determine whether the hairstyling device is being used according to a first styling behaviour or a second, different styling behaviour; and

control heating of the hair contact member in dependence on whether the hairstyling device is being used according to the first styling behaviour or the second styling behaviour.

15 . The hairstyling device according to claim 14 , wherein the controller is configured to cause the operating temperature of the hair contact member to increase at a rate that is dependent on the whether the hairstyling device is being used according to the first styling behaviour or the second styling behaviour.

16 . The hairstyling device according to claim 1 ,

wherein the hairstyling device comprises a heating element operable to heat the hair contact member, and

wherein the controller is configured to control the heating element to cause the operating temperature of the hair contact member to change as the hair contact member moves along the tress from the first end towards the second end.

17 . The hairstyling device according to claim 1 , wherein the hairstyling device comprises a hair straightening device and/or a hair curling device.

18 . A hairstyling device comprising:

a heatable hair contact member having a hair-contactable surface, the hair contact member being operable to apply heat to a tress of hair of a user via the hair-contactable surface by movement of the hair contact member along the tress of hair between a first end of the tress and a second end of the tress;

sensor equipment configured to generate a sensor output dependent on movement of the hair contact member; and

a controller configured to:

receive the sensor output from the sensor equipment;

determine, based on the sensor output, that the hair contact member is moving along the tress from a first end of the tress towards a second end of the tress, comprising determining a displacement of the hair contact member from the first end of the tress;

determine, based on the sensor output, a speed of the hair contact member;

based on the determined displacement and the determined speed, control heating of the hair contact member to cause the operating temperature of the hair contact member to change as the hair contact member moves along the tress from the first end of the tress towards the second end of the tress; and

cause the operating temperature of the hair contact member to increase at a rate dependent on the determined speed.

19 . A hairstyling device comprising:

a heatable hair contact member having a hair-contactable surface, the hair contact member being operable to apply heat to a tress of hair of a user via the hair-contactable surface by movement of the hair contact member along the tress of hair between a first end of the tress and a second end of the tress;

sensor equipment configured to generate sensor output indicative of current use of the hairstyling device; and

a controller configured to:

determine that the hair contact member is moving along the tress from a first end of the tress towards a second end of the tress;

based on the determining, control heating of the hair contact member to cause the operating temperature of the hair contact member to change as the hair contact member moves along the tress from the first end of the tress towards the second end of the tress; and

cause the operating temperature of the hair contact member to increase at a predetermined rate as the hair contact member moves along the tress from the first end towards the second end.

20 . A hairstyling device comprising:

a heatable hair contact member having a hair-contactable surface, the hair contact member being operable to apply heat to a tress of hair of a user via the hair-contactable surface by movement of the hair contact member along the tress of hair between a first end of the tress and a second end of the tress;

sensor equipment configured to generate sensor output indicative of current use of the hairstyling device;

a heating element operable to heat the hair contact member; and

a controller configured to:

determine that the hair contact member is moving along the tress from a first end of the tress towards a second end of the tress;

determine whether the hairstyling device is being used according to a first styling behaviour or a second, different styling behaviour;

control heating of the hair contact member, by controlling the heating element, to cause the operating temperature of the hair contact member to change as the hair contact member moves along the tress from the first end of the tress towards the second end of the tress in dependence on whether the hairstyling device is being used according to the first styling behaviour or the second styling behaviour.