High aperture LCD with insulating color filters overlapping bus lines on active substrate
View Patent ↗A high aperture active matrix liquid crystal display (AMLCD) includes pixel electrodes in respective pixels which overlap adjacent address lines. The color filters are formed on the active substrate in a manner such that the filters also overlap the address lines and function as an insulating layer between the pixel electrodes and address lines in the areas of overlap. Accordingly, line-pixel capacitances are reduced and the resulting AMLCD is easier to manufacture. The total number of process step in manufacturing is reduced, and plate-to-plate (active to passive plate) alignment is much easier and less important.
1. A liquid crystal display (LCD) device having a plurality of pixels, each pixel comprising:
first and second substrates;
a gate electrode and a gate line on the first substrate;
a gate insulating layer on the gate electrode;
a semiconductor layer on the gate insulating layer;
source and drain electrodes and a data line on the semiconductor layer;
a photo imageable color filter layer in each pixel, spaced from one another, the photo imageable color filter layer overlapping the gate and data lines and having a dielectric constant less than about 5.0 and a thickness in a range between about 0.5 μm and about 2.0 μm;
a contact hole in the photo imageable color filter layer;
a pixel electrode having a thickness in a range between about 300 Å and about 900 Å directly on the photo imageable color filter layer in each pixel and electrically connected to the drain electrode through the contact hole;
a storage capacitor having a first electrode of the gate line and a second electrode, the second electrode provided within the gate line and connected to the pixel electrode through another contact hole in the photo imageable color filter layer; and
a liquid crystal layer between the first and second substrates,
wherein the photo imageable color filter layer is of a photo imageable material with a color filter pigment or dye added thereto,
wherein a parasitic capacitance between the pixel electrode and the data line is no greater than 0.01 pF with a reference pixel pitch of about 150 μm, and
wherein an aperture ratio of the LCD display is in a range between about 68% and about 80%.
2. The LCD device according to claim 1 , wherein the photo imageable color filter layer has one of red, green, and blue colors.
3. The LCD device according to claim 1 , wherein the photo imageable color filter layer is transparent.
4. The LCD device according to claim 1 , wherein the photo imageable color filter layer has a dielectric constant less than about 3.0.
5. The LCD device according to claim 1 , wherein the photo imageable color filter layer is made of an organic insulating material.
6. The LCD device according to claim 1 , wherein the photo imageable color filter layer is a negative resist.
7. The LCD device according to claim 1 , wherein the photo imageable color filter layer has a refractive index between about 1.5 to about 2.0.