Image sensing device
An image sensing device may include an image sensing pixel array including a plurality of image sensing pixels operable to respond to light and to produce imaging pixel signals, and a first grid structure disposed between image sensing pixels to separate adjacent image sensing pixels. The image sensing pixel array is structured to include a center area located at or near a center of the image sensing pixel array, first and second diagonal edge areas disposed on opposite sides of the center area in a first diagonal direction, and third and fourth diagonal edge areas disposed on opposite sides of the center area in a second diagonal direction that is different from the first diagonal direction. The first grid structure includes a bent portion in at least one of the first to fourth diagonal edge areas to cover one vertex and adjacent parts of each image sensing pixel.
1. An image sensing device comprising:
an image sensing pixel array including a plurality of image sensing pixels operable to respond to light and to produce imaging pixel signals; and
a plurality of first grid structures disposed between image sensing pixels to separate adjacent image sensing pixels,
wherein the image sensing pixel array is structured to include a center area located at or near a center of the image sensing pixel array, first and second diagonal edge areas disposed on opposite sides of the center area in a first diagonal direction, and third and fourth diagonal edge areas disposed on opposite sides of the center area in a second diagonal direction that is different from the first diagonal direction,
wherein a length of each of the first grid structures in the center area is smaller than a length of a corresponding side of a corresponding image sensing pixel,
wherein each of the plurality of first grid structures in the first to the fourth diagonal edge areas includes a bent portion to cover one vertex and adjacent parts of each image sensing pixel to separate the imaging pixel from adjacent image sensing pixels,
wherein each of the plurality of first grid structures includes a low index layer having a refractive index lower than a refractive index of surroundings,
wherein the low index layer of the bent portion in the first grid structure corresponding to a first image sensing pixel in one of the first to fourth diagonal edge areas is physically isolated from the low index layer of the bent portion in the first grid structure corresponding to a second image sensing pixel adjacent to the first image sensing pixel,
wherein each of the plurality of first grid structures in the first to the fourth diagonal edge areas is in contact with three image sensing pixels,
wherein the first grid structures located in the center region are symmetrically located on four sides of each image sensing pixel, and
wherein the bent portion of a first grid structure in the first to fourth diagonal edge areas covers only one vertex of each image sensing pixel that is farthest from the center region and portions of adjacent sides of the vertex.
2. The image sensing device of claim 1 , wherein the low index layer includes a structure filled with air.
3. The image sensing device of claim 1 , wherein each of the first grid structures includes an L-shaped structure disposed at a vertex of the image sensing pixel.
4. The image sensing device of claim 3 , wherein the center area further comprises a second grid structure disposed between the first grid structure to physically isolate the first grid structures from each other.
5. The image sensing device of claim 4 , wherein the second grid structure includes a material layer different from the low-index layer.
6. The image sensing device of claim 3 , wherein a length of each of the first grid structures in the center area is smaller than a length of the corresponding side of the image sensing pixel.
7. The image sensing device of claim 1 , wherein each of the first grid structures further comprises a first capping film configured to cover the low-index layer.
8. The image sensing device of claim 7 , wherein the first capping film has a higher refractive index than the low-index layer, and a lower refractive index than a color filter abutting the first grid structure.
9. The image sensing device of claim 7 , wherein each of the first grid structures further comprises a second capping film configured to cover the first capping film and having a larger thickness than the first capping film.
10. The image sensing device of claim 7 , wherein each of the first grid structures further comprises a metal layer disposed under the low-index layer and formed of metal.
11. The image sensing device of claim 1 , wherein a direction facing a vertex of an image sensing pixel of the plurality of image sensing pixels that is surrounded by the first grid structure from a center of the image sensing pixel corresponds to a direction facing a diagonal edge area including the image sensing pixel among the first to fourth diagonal edge areas from the center area of the image sensing pixel array.
12. The image sensing device of claim 11 , wherein the first diagonal edge area is disposed on a first side of the center area, and comprises an L-shaped first grid structure disposed at a first vertex of the image sensing pixel corresponding to the first side of the center area.
13. The image sensing device of claim 11 , wherein the second diagonal edge area is disposed on a second side of the center area, and comprises an L-shaped first grid structure disposed at a second vertex of the image sensing pixel corresponding to the second side of the center area.
14. The image sensing device of claim 11 , wherein the third diagonal edge area is disposed on a third side of the center area, and comprises an L-shaped first grid structure disposed a third vertex of the image sensing pixel corresponding to the third side of the center area.
15. The image sensing device of claim 11 , wherein the fourth diagonal edge area is disposed on a fourth side of the center area, and comprises an L-shaped first grid structure disposed at a fourth vertex of the image sensing pixel corresponding to the fourth side of the center area.
16. The image sensing device of claim 1 , wherein the image sensing pixel array further comprises first and second horizontal edge areas disposed on both sides of the center area along a horizontal line passing through the center area, and first and second vertical edge areas disposed on both sides of the center area along a vertical line passing through the center area,
wherein the shapes and positions of the first grid structures included in the first and second horizontal edge areas and the first and second vertical edge areas, respectively, correspond to the shape and position of the first grid structure included in the center area.
17. The image sensing device of claim 16 , wherein from any one area of the first horizontal edge area, the second horizontal edge area, the first vertical edge area and the second vertical edge area, toward the diagonal edge area adjacent to the any one area, the position of the first grid structure gradually gets close to the vertex where the first grid structure included in a diagonal edge area adjacent to the any one area is located.