An imaging system includes first and second heaters configured to pre-heat a thermochromic coating. The first heater heats at least one of a substrate and the thermochromic coating disposed on the substrate. The second heater heats an ambient environment surrounding the thermochromic coating. The first and second heaters are configured to pre-heat the thermochromic coating to a temperature below a threshold temperature of the thermochromic coating. The system further includes a patterned heater configured to heat the pre-heated thermochromic coating to one or more temperatures above the threshold temperature according to a predetermined pattern.

An imaging system includes first and second heaters configured to pre-heat a thermochromic coating. The first heater heats at least one of a substrate and the thermochromic coating disposed on the substrate. The second heater heats an ambient environment surrounding the thermochromic coating. The first and second heaters are configured to pre-heat the thermochromic coating to a temperature below a threshold temperature of the thermochromic coating. The system further includes a patterned heater configured to heat the pre-heated thermochromic coating to one or more temperatures above the threshold temperature according to a predetermined pattern.

Formation of a multi-colored image in thermochromic material involves controlling operation of first, second, and third heat sources. The first heat source heats pixels of the thermochromic material to activate the pixels. The second and third heat sources are selectively controlled to heat different sets of pixels using neither, one, or both of the second and third heat sources.

The temperature evaluation system is provided with: a read-in device that acquires image data pertaining to the indicator; a storage device that stores the relationship between color density and temperature for each thermosensitive material; and a processing device provided with a color density estimation unit that estimates the color density of the thermosensitive material from the image data, a material identification unit that specifies the thermosensitive material used in the indicator, and a temperature estimation unit that selects, from among the relationships between color density and temperature for each thermosensitive material, the relationship between color density and temperature of the thermosensitive material specified by the material identification unit, and that estimates the highest temperature reached or the lowest temperature reached from the relationship between color density and temperature of the specified thermosensitive material and the color density estimated by the color density estimation unit.

The temperature evaluation system is provided with: a read-in device that acquires image data pertaining to the indicator; a storage device that stores the relationship between color density and temperature for each thermosensitive material; and a processing device provided with a color density estimation unit that estimates the color density of the thermosensitive material from the image data, a material identification unit that specifies the thermosensitive material used in the indicator, and a temperature estimation unit that selects, from among the relationships between color density and temperature for each thermosensitive material, the relationship between color density and temperature of the thermosensitive material specified by the material identification unit, and that estimates the highest temperature reached or the lowest temperature reached from the relationship between color density and temperature of the specified thermosensitive material and the color density estimated by the color density estimation unit.

A thermochromic display board is described that includes an array of nanofiber yarns in contact with an electrode. When electrified, the nanofiber yarns generate heat. This heat causes a thermochromic transition in a thermochromic layer. The presence of the nanofiber yarns, which are thermally conductive, can increase the rate at which the thermochromic layer within the di splay board transitions between thermochromic states.

Disclosed is a substrate which has thereon a marking or layer comprising a salt-free cured chiral liquid crystal precursor composition which comprises one or more nematic compounds A and one or more chiral dopant compounds B which are capable of giving rise to a cholesteric state of the chiral liquid crystal precursor composition and are of formula (I) as set forth herein. A modifying resin made from one or more polymerizable monomers comprising an average of at least one ether functionality per polymerizable group is disposed between the substrate and the marking or layer and in contact with the marking or layer in one or more areas thereof. The modifying resin changes the position of a selective reflection band exhibited by the cured chiral liquid crystal precursor composition on the substrate in the one or more areas.

An approach for forming a multi-colored image on a substrate that includes a thermochromic material capable of producing at least two different colors is disclosed. Individually selected pixels of the thermochromic material that correspond to the image are heated to predetermined temperatures. Each predetermined temperature corresponds to a predetermined color shift of the thermochromic material. While the individually selected pixels are being heated, an area that includes the individually selected pixels is flooded with an amount of UV radiation sufficient to at least partially polymerize the thermochromic material. A color of each individually selected pixel is determined by a predetermined temperature to which the pixel is heated and the amount of UV radiation to which the pixel is exposed.

A method of forming a multi-colored image on a substrate that includes a thermochromic material capable of producing at least two different colors is disclosed. The method includes heating individually selected pixels of the thermochromic material that correspond to the image to one or more first temperatures sufficient to activate the selected pixels of the thermochromic material for color shift. The area corresponding to the individually selected pixels is flooded with a first UV radiation dosage sufficient to at least partially polymerize the thermochromic material. The individually selected pixels are heated to one or more second temperatures while the area is flooded with a second UV radiation dosage.

Aspects of the invention include color change compositions having a color former and color developer composition that transitions from a first color state to a second color state upon application of an applied stimulus and an amount of a copolymer sufficient to eliminate background color of the color former and color developer composition during transition from the first color state to the second color state. Methods for preparing and devices employing the color change compositions of the invention are also described.