Device, kit and method for coloring hair

Abstract

A hair-penetrating shield 220 comprises a tooth array having top 280 and bottom 290 surfaces. In some embodiments, for a majority of the teeth, a cross section of each tooth (for example, triangular in shape) has an asymmetric width profile such that the tooth cross section, on average, is narrower near the top of the tooth and wider near the bottom of the tooth. In some embodiments, a ratio between: i) a first average tooth width describing the average tooth width below the top-bottom midpoint; and ii) a second average tooth width describing the average tooth width above the top-bottom midpoint is at least 1.2, or at least 1.6. In some embodiments, a non-viscous hair-coloring agent is dispensed as a mist over the top of the surface of the shield so as to color roots of hair passing through the spaces between the teeth of the user's hair. In some embodiments, closely-spaced teeth of the hair penetrating shield protect the user's scalp from the non-viscous hair-coloring agent. Related methods and kits are disclosed herein.

1 - 25 . (canceled) 
     
     
         26 . A kit for coloring hair roots, the kit comprising:
 a. a hair-penetrating shield comprising a tooth array having top and bottom surfaces and having proximal and distal ends, the tooth array including at least eight closely-spaced teeth such that for a majority of teeth of the tooth array:
 i. each tooth of the majority includes a main portion and a tapered distal portion for facilitating hair penetration; and 
 ii. for each tooth of the majority, the main portion includes a section having a length of at least 2.5 cm where for most locations along the tooth axis within the section:
 A. a cross section of the tooth has an asymmetric width profile along the shield thickness axis such that the tooth cross section, on average, is narrower near the top of the tooth and the tooth cross section, on average, is wider near the bottom of the tooth; 
 B. the tooth cross-section is less than 5 mm̂2; and 
 C. the tooth is separated from a laterally neighboring tooth to provide a minimum gap distance that is between 0.3 mm and 1 mm, and 
 
 b. an aerosol assembly, the aerosol assembly including an aerosol outlet elevated above the top surface of the shield, the aerosol assembly configured to dispense a non-viscous hair-coloring agent as a mist in a proximal-distal direction defined by the array of teeth onto the top surface of the shield such that the hair-penetrating shield protects the space beneath the bottom surface from the non-viscous hair-coloring agent. 
   
     
     
         27 . A hair-coloring device comprising:
 the kit of  claim 26  wherein the hair-penetrating shield is coupled to the aerosol assembly.   
     
     
         28 . The hair-coloring device of  claim 27  wherein each tooth has a top-bottom midpoint that is midway between the tooth's top and bottom, and wherein for the majority of teeth of the tooth array, for most locations along the tooth axis within the section, a width ratio between:
 i. a first average tooth width describing the average tooth width below the top-bottom midpoint; 
 ii. a second average tooth width describing the average tooth width above the top-bottom midpoint is at least 1.2. 
 
     
     
         29 . The hair coloring device of  claim 27  wherein, for the majority of teeth, for most locations along the tooth axis, the tooth cross section is less than 3 mm̂2. 
     
     
         30 . The hair coloring device of  claim 27  wherein, for the majority of teeth, for most locations along the tooth axis wherein:
 i. each pair of laterally neighboring teeth T 1  and T 2  are positioned to form a respective intertooth lateral void that is in between the laterally neighboring teeth within a height range having upper and lower bounds:
 A. the upper bound being the lower height of the top of tooth T 1  and the top of tooth T 2 , and 
 B. the lower bound being the greater height of the bottom of tooth T 1  and the bottom of tooth T 2 , and 
 
 ii. a cross section of the respective intertooth void has an asymmetric width profile along the shield thickness axis such that the void cross section, on average, is wider near the top of the intertooth void and the intertooh void, on average, is narrower near the bottom of the intertooth void. 
 
     
     
         31 . The hair coloring device of  claim 27  wherein:
 i. each void has a top-bottom void mid-height level that is midway between upper and lower bounds of the height range; 
 ii. for the majority of teeth of the tooth array, for most locations along the tooth axis within the section, a width ratio between:
 A. a first average void width describing the average void width above the top-bottom void mid-height level; 
 B. a second average void width describing the average void width below the top-bottom void mid-height level, is at least  1 . 2 . 
 
 
     
     
         32 . A method of touching up hair roots of an individual, the method comprising:
 a. providing a hair-penetrating shield comprising a tooth array having top and bottom surfaces and having proximal and distal ends, the tooth array including at least eight closely-spaced teeth such that for a majority of teeth of the tooth array:
 i. each tooth of the majority includes a main portion and a tapered distal portion for facilitating hair penetration; and 
 ii. for each tooth of the majority, the main portion includes a section having a length of at least 2.5 cm where for most locations along the tooth axis within the section:
 A. a cross section of the tooth has an asymmetric width profile along the shield thickness axis such that the tooth cross section, on average, is narrower near the top of the tooth and the tooth cross section, on average, is wider near the bottom of the tooth; 
 B. the tooth cross-section is less than 5 mm̂2; and 
 C. the tooth is separated from a laterally neighboring tooth to provide a minimum gap distance that is between 0.3 mm and 1 mm, and 
 
   b. engaging the hair-penetrating shield to a user's head so that the bottom surface of the shield faces that user's scalp and so that root regions of the user's hair pass through spaces between the teeth of the shield; and   c. dispensing a non-viscous hair-coloring agent as a mist on the top surface of the shield so as to color the root regions of the user's hair such that the hair-penetrating shield protects, from the non-viscous hair-coloring agent, the user's scalp that is facing the bottom surface of the shield.   
     
     
         33 . A hair-coloring device for coloring hair roots, the device comprising:
 a) a hair-penetrating shield having top and bottom surfaces, comprising a slot array having at least eight elongated shield-thickness-spanning narrow slots that are substantially aligned a proximal-distal direction, the hair-penetrating shield including a longitudinal section of at least 2.5 cm where:
 i) for a majority of slots of the array, each slot provide a shield-thickness-spanning property throughout a majority of the longitudinal section; 
 ii) an array-wide average cross-section-minimum-slot width is between 0.3 mm and 1 mm and/or for the majority of slots of the array each provide, throughout a majority of the longitudinal-subsection cross-section-minimum-slot width that is between 0.3 mm and 1 mm; 
 iii) for the majority of slots of the slot array, a slot aspect ratio within the longitudinal section is at least 30, the slot aspect ratio being defined by a ratio between the slot length within the section and an individual-slot longitudinal-averaged cross-section-minimum-slot width averaged over the longitudinal section; 
   iv) an array-wide average slot-slot lateral distance within the longitudinal section is at most 3 mm and/or at most a value equal to 3 times the array-wide average cross-section-minimum-slot width within the longitudinal section the hair-penetrating shield including a plurality of elongated, tapered penetrating elements located at the distal end of the shield ; and;   b) an aerosol assembly coupled to the hair-penetrating shield, the aerosol assembly including an aerosol outlet elevated above the top surface of the shield, the aerosol assembly configured to dispense a non-viscous hair-coloring agent as a mist in a proximal-distal direction defined by the array of teeth onto the top surface of the shield such that the hair-penetrating shield protects the space beneath the bottom surface from the non-viscous hair-coloring agent.   
     
     
         34 . The device of  claim 33  wherein for each slot of the majority of slots, for most longitudinal locations within the longitudinal section, the slot exhibits an asymmetric width profile along the shield thickness axis such that the slot thickness is narrower near the bottom surface of the shield than it is near the top surface of the shield. 
     
     
         35 . The device of  claim 33  wherein for a majority of a region that is laterally bound by the first and last slot of the slot array and within the longitudinal section, the top surface is rough relative to the bottom surface for a topographic length scale of 1 mm. 
     
     
         36 . The hair coloring device of  claim 33  wherein the slot array having at least  14  elongated shield-thickness-spanning narrow slots.