Hair stying device

Abstract

A hair styling device comprises an optical radiation source (L) for radiating hair (H), a sensor unit (S) for measuring effects from radiating hair (H), and a feedforward control device for controlling the optical radiation source (L) in dependence on a signal from the sensor unit (S). The optical radiation source (L1, L2) may produce a first flash having a first energy density that may be lower than required for photo-thermal hair reshaping, the optical radiation source being controlled to produce a subsequent flash in dependence on a sensor signal obtained in response to the first flash, which subsequent flash may have at least the first energy density. The sensor unit (S) may include a sensor arranged before the optical radiation source in a hair flow direction. The hair styling device may comprise, along a direction in which the hair (H) is guided, a first sensor (Si), a first LED unit (L1) being controlled in dependence on a signal from the first sensor (Si), a second sensor (S2), and a second LED unit (L2) being controlled in dependence on a signal from the second sensor (S2). The direction in which hair is guided through the hair styling device may determine which part of the optical radiation source will act as the first LED unit (L1). The hair styling device may comprise a drive mechanism (D) to move the hair (H) along the optical radiation source (L) at a speed controlled by the feedforward control device in dependence on the signal from the sensor unit (S).

1 . A hair styling device comprising:
 an optical radiation source for radiating hair,   a sensor unit for measuring effects from radiating hair; and   a feedforward control device for controlling the optical radiation source in dependence on a signal from the sensor unit.   
     
     
         2 . The hair styling device as claimed in  claim 1 , wherein the optical radiation source is controlled to produce a first flash having a lower energy density than required for photo-thermal hair reshaping, the optical radiation source being controlled to produce a subsequent flash in dependence on a sensor signal obtained in response to the first flash. 
     
     
         3 . The hair styling device as claimed in  claim 1 , wherein the optical radiation source is controlled to produce a first flash having a first energy density, the optical radiation source being controlled to produce a subsequent flash in dependence on a sensor signal obtained in response to the first flash, the subsequent flash having at least the first energy density. 
     
     
         4 . The hair styling device as claimed in  claim 1 , wherein the sensor unit includes a sensor arranged before the optical radiation source in a hair flow direction. 
     
     
         5 . The hair styling device as claimed in  claim 1 , comprising, along a direction in which the hair is guided, a first sensor, a first LED unit being controlled in dependence on a signal from the first sensor, a second sensor, and a second LED unit being controlled in dependence on a signal from the second sensor. 
     
     
         6 . The hair styling device as claimed in  claim 5 , wherein the direction in which hair is guided through the hair styling device determines which part of the optical radiation source will act as the first LED unit. 
     
     
         7 . The hair styling device as claimed in  claim 1 , wherein the sensor unit includes LEDs that momentarily do not produce light. 
     
     
         8 . The hair styling device as claimed in  claim 1 , comprising a drive mechanism to move the hair along the optical radiation source at a speed controlled by the feedforward control device in dependence on the signal from the sensor unit.