Liquid crystal display device, optical element, method of fabricating the liquid crystal display device and method of making the optical element

A method of fabricating a liquid crystal display device, the device including:

• two substrates;
• a liquid crystal layer that is sandwiched between the two substrates;
• and two alignment films, each of the alignment films being provided on one surface of associated one of the substrates so as to face the liquid crystal layer, the liquid crystal display device defining multiple picture elements, the method comprising the steps of:
• (a) preparing the two substrates;
• (b) forming at least one of the two alignment films of a polymer material on the surface of at least one of the two substrates, the polymer material including:
• a main chain;
• an atomic group having a bond that is selectively cut when exposed to an actinic ray;
• and a side chain that is bonded to the main chain by way of the atomic group, the polymer material with the side chain giving a pretilt angle of greater than 85 degrees but 90 degrees or less to liquid crystal molecules of the liquid crystal layer;
• (c) exposing at least one region of the alignment film to the actinic ray, thereby cutting the bond of the atomic group of the polymer material in the at least one region and removing the side chain;
• and
• (d) forming the liquid crystal layer that includes liquid crystal molecules to which a pretilt angle of 2 degrees to 15 degrees has been given by the at least one region of the alignment film.

An optical element comprising two alignment films and a birefringence medium layer that is sandwiched between the two alignment films,

• wherein the birefringence medium layer includes liquid crystal molecules of which the orientation state is regulated by the two alignment films, and
• wherein at least one of the two alignment films is made of a polymer material, the polymer material including:
• a main chain;
• an atomic group having a bond that is selectively cut when exposed to an actinic ray;
• and a side chain that is bonded to the main chain by way of the atomic group, and
• wherein the polymer material with the side chain is able to give a pretilt angle of greater than 85 degrees but 90 degrees or less to the liquid crystal molecules, and
• wherein the polymer material without the side chain is able to give a pretilt angle of 2 degrees to 15 degrees to the liquid crystal molecules.

A method of making an optical element, the optical element including two alignment films and a birefringence medium layer that is sandwiched between the two alignment films, the method comprising the steps of:

• (a) forming at least one of the two alignment films of a polymer material, the polymer material including:
• a main chain;
• an atomic group having a bond that is selectively cut when exposed to an actinic ray;
• and a side chain that is bonded to the main chain by way of the atomic group, the polymer material with the side chain giving a pretilt angle of greater than 85 degrees but 90 degrees or less to liquid crystal molecules of the birefringence medium layer;
• (b) exposing at least one region of the alignment film to the actinic ray, thereby cutting the bond of the atomic group of the polymer material in the at least one region and removing the side chain;
• and
• (c) forming the birefringence medium layer that includes liquid crystal molecules to which a pretilt angle of 2 degrees to 15 degrees has been given by the at least one region of the alignment film.

A material of a liquid crystal alignment film, the material being made of a polymer material that includes:

• a main chain;
• an atomic group having a bond that is selectively cut when exposed to an actinic ray;
• and a side chain that is bonded to the main chain by way of the atomic group,
• wherein the polymer material with the side chain is able to give a pretilt angle of greater than 85 degrees but 90 degrees or less to liquid crystal molecules, and
• wherein the polymer material without the side chain is able to give a pretilt angle of 2 degrees to 15 degrees to the liquid crystal molecules.

A material of a liquid crystal alignment film, the material being made of a polymer material that includes:

• a main chain;
• an atomic group having a bond that is selectively cut when exposed to an actinic ray;
• and a side chain that is bonded to the main chain by way of the atomic group,
• wherein the atomic group includes at least one compound that is selected from the group consisting of benzoyl peroxide, benzoyl ether and derivatives thereof.