Transparent composite material having ridge portion formed in transparent resistance film for transparent coordinate input device
View Patent ↗A transparent composite material is able to promote visibility in a transparent coordinate input device due to the reflection of display light while the generation of an interference fringe at an input operating time is restrained. Many ridge portions extending in one direction are formed on the surface of a first transparent resistance film. Such ridge portions are projected stripes formed in a triangular shape in section, and are constructed by alternately forming one set of slanting faces on the surface of the first transparent resistance film.
1. A transparent composite material for a transparent coordinate input device, comprising:
a transparent base material disposed over a liquid crystal display panel and a light device comprising a light source and a light guiding plate;
a transparent resistance film formed on a surface of the transparent base material; and
a plurality of ridge portions formed on the surface of the transparent base material,
wherein the transparent base material is disposed between the transparent resistance film and the liquid crystal display panel, and is disposed between the transparent resistance film and the light device, the surface of the transparent resistance film in each section of the ridge portions includes a vertex, a first inclined plane, and a second inclined plane, wherein the first inclined plane is formed at one side with respect to the vertex and the second inclined plane is formed at the other side with respect to the vertex, and the first and second inclined planes are symmetrically in-line with respect to the vertex;
wherein a height (H) between the vertex of the surface of the transparent resistance film in each section of the ridge portions and the lowest part of the surface of the transparent resistance film is formed over a valley between adjacent ridge portions, and ranges from 0.1 μm to 10 μm;
wherein the ridge portions are transparent, have a polygonal shape in section, are narrow in width, and are formed as projected strips longitudinally extending in one direction;
wherein the ridge portions are adjacent to each other, and are formed with a predetermined constant pitch by repeating the ridge portions;
wherein the polygonal shape is a triangular shape or a triangular shape with a curved top, the triangular shape or the triangular shape with a curved top having a vertical angle that is an obtuse angle;
wherein a surface of the transparent resistance film formed on the upper face of the ridge portions is formed along the projected stripes longitudinally extending in one direction of the ridge portions, and has an obtuse vertical angle in each section of the ridge portions;
wherein an angle formed by the first inclined plane and the second inclined plane is an obtuse angle, and the obtuse angle in each section of the ridge portions is constant; and
wherein the constant pitch of the ridge portions is between 100 μm and 500 μm, inclusive.
2. The transparent composite material for a transparent coordinate input device according to claim 1 , wherein an angle of a valley between the ridge portions adjacent to each other in section is an obtuse angle.
3. The transparent composite material for a transparent coordinate input device according to claim 1 , wherein the surface of the transparent resistance film formed on the upper face between the ridge portions adjacent to each other has an obtuse valley angle in section.
4. The transparent composite material for a transparent coordinate input device according to claim 1 , wherein the thickness of the transparent resistance film ranges from 0.01 μm to 0.05 μm.
5. The transparent composite material for a transparent coordinate input device according to claim 1 , wherein the transparent coordinate input device comprising:
another transparent base material facing the transparent base material with a clearance therebetween and having another transparent resistance film disposed on a face thereof opposing the transparent resistance film,
wherein the transparent base material is disposed below the another transparent base material.
6. The transparent composite material for a transparent coordinate input device according to claim 5 , wherein the another transparent material and the another transparent resistance film are configured to flex toward the transparent base material based on input received during operation such that the another transparent resistance film contacts the transparent resistance film and that an interference fringe is generated on the first and second inclined planes.