LOW-COST LARGE-SCREEN WIDE-ANGLE FAST-RESPONSE LIQUID CRYSTAL DISPLAY APPARATUS
The present invention discloses a super large wide-angle high-speed response liquid crystal display apparatus manufactured by using a photolithographic procedure for three times. The invention adopts a halftone exposure technology to form a gate electrode, a common electrode, a pixel electrode and a contact pad, and then uses the halftone exposure technology to form a silicon (Si) island and a contact hole, and a general exposure technology to form a source electrode, a drain electrode and an orientation control electrode. A passivation layer uses a masking deposition method. A film is formed by using a P—CVD method, or a protective area is formed at a local area by using an ink coating method or spray method, and a TFT array substrate used for the super large wide-angle high-speed response liquid crystal display apparatus manufactured by using a photolithographic procedure for three times can be produced.
The present invention relates to a large-screen wide-angle liquid crystal display apparatus manufactured by using a halftone exposure method.
BACKGROUND OF THE INVENTIONIn multi-domain vertical alignment (MVA) liquid crystal display apparatuses, an orientation control electrode for controlling an alignment of a liquid crystal molecule has been disclosed in Japan Laid Open Patents Nos. 07-230097, 11-109393 and 2001-042347.
SUMMARY OF THE INVENTIONIn view of the shortcomings of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct researches and experiments, and finally developed a large-screen wide-angle liquid crystal display apparatus in accordance with the present invention to overcome the foregoing shortcomings.
Therefore, it is a primary objective of the present invention to adopt a prior art orientation control electrode of an LCD panel structure to correspond to smaller pixels. Since only one type of orientation control electrode is used only, and the edge field effect of a pixel electrode is adopted, therefore it is not applicable for lager pixels.
At present, the mainstream of multi-domain vertical alignment (MVA) liquid crystal display apparatus generally uses a bump or slit electrode for the alignment control of the sides of a color filter (CF) substrate, and this method can make a proper alignment if the pixel is large, but the cost of CF substrates is high, and becomes an obstacle for manufacturing a large-screen liquid crystal TV by a low cost.
Therefore, it is a primary objective of the present invention to reduce the number of photolithographic procedures of the TFT active matrix substrate and the CF substrate during the manufacture of the TFT active matrix liquid crystal display apparatus, in order to shorten the manufacturing procedure, lowering the manufacturing cost, and improving the yield rate.
The technical measures taken by the present invention are described as follows.
In Measure 1, unstable and swinging discrimination lines are avoided, and two types of orientation control electrodes are installed at an upper layer of a pixel electrode through an insulating film, and between common electrodes corresponding to the pixel electrodes. With the foregoing two different types of orientation control electrodes, the oblique direction of anisotropic liquid crystal molecules having a negative dielectric constant can be controlled precisely.
In Measure 2, one type of orientation control electrode is installed at an upper layer of a pixel electrode through an insulating film, and a slender slit is formed in the pixel electrode, and these two alignment control mechanisms can control the oblique direction of anisotropic liquid crystal molecules having a negative dielectric constant precisely.
In Measure 3, the orientation control electrodes as used in Measures 1 and 2 is connected to the pixel electrodes as closer to the substrate as possible.
In Measure 4, the alignment control mechanisms as used in Measures 1 and 2 provides four perfect area alignments for a curvature of 90 degrees at a position proximate to the center of the pixel.
In Measure 5, a halftone exposure method is introduced into the manufacturing process of the TFT array substrate to reduce the number of photolithographic procedures.
In Measure 6, a basic unit pixel is divided into two sub pixels, and the common electrodes are installed parallelly on a video signal line, and the common electrodes of odd-numbered rows and even-numbered rows switch signals with different polarities in each scan period, and produce different voltages applied to the liquid crystal molecules of the two sub pixels.
With Measures 1 and 2, the TFT array substrate has all alignment control functions, and thus it is not necessary to form a pad or slit on the CF substrate for the alignment control, so that the MVA LCD panel can be manufactured with a low-cost CF substrate to lower the cost and improve the yield rate.
With Measure 3, the orientation control electrode connected to the pixel electrode is proximate to the substrate for enhancing the rotational torque of an electric field of anisotropic liquid crystal molecules having negative dielectric constant and acted at the vertical alignment, so as to achieve a high-speed response.
With Measure 4, unnecessary discrimination lines can be avoided to improve the overall light transmission rate of the screen and reduce unevenness of the LCD panel.
With Measures 1, 2 and 5, the processing costs for both CF substrate and TFT array substrate can be lowered, and thus the manufacturing cost of MVA LCD panels can be lowered significantly; the production efficiency can be improved, and the yield rate can be enhanced.
With Measures 5 and 6, the liquid crystal alignment control mechanism can be manufactured by a very simple manufacturing process, and the correction of y curve can be achieved by a very simple circuit, and thus a little cost is incurred for enhancing the display quality of a MVA liquid crystal display apparatus.
To make it easier for our examiner to understand the objective, innovative features and performance of the present invention, we use a preferred embodiment and the accompanying drawings for a detailed description of the present invention.
Referring to
Referring to
With the two basic structures as shown in
From
If a cell gap is greater than 5 μm, the structure of a pixel electrode of a TFT substrate connected to the liquid crystal orientation control electrode in accordance wit the present invention almost has no effect. However, if the cell gap is below 3 μm, the effect is significant. If the cell gap is below 2.5 μm, a sufficiently equal-potential distribution diagram is formed for controlling the alignment of liquid crystal molecules.
Referring to
Referring to
In the first of the three times of photolithographic procedure ass shown in
Since aluminum alloy is used for making a scan line (or a gate electrode) in this invention, therefore ITO cannot be used in the pixel electrode, because a partial battery reaction will result, and the abnormal corrosion or ITO blackening issues usually occur. As a result, the pixel electrode is generally a transparent electrode made of a thin film oxide such as titanium nitride or zirconium nitride.
The nitride of the transparent pixel electrode and the P—SiNxo of the gate insulating film cannot have a large selectivity for creating a contact hole by a y etching method, and the manufacturing processes of the previous embodiments as shown in
In the second time of the photolithographic procedure, the thin film semiconductor components are separated and the contact hole is formed, and this procedure is illustrated in
In the third photolithographic procedure as shown in
In
In
Referring to
Embodiments 1 and 2 of the present invention include all alignment control functions at the TFT substrate side. Compared with the previous methods as shown in
Referring to
Referring to
The common electrode has not been divided into two, but both upper and lower portions integrated.
Even the modes of liquid crystals are different, the circuit models of the common electrode and the video signal line is identical to those as shown in
The common electrode has not been divided into two, but it is connected from top to bottom as a whole. To prevent the blocks of upper and lower screens from being separated, the video signals are written from the center of the screen upward or downward, or the video signals are written from the top or bottom of the screen towards the center of the screen. The driving method for the scan lines is identical to that of Embodiment 3.
Referring to
Since a poor alignment area as shown in
Even if the FFS TFT substrate as shown in
Claims
1. An active matrix vertical alignment liquid crystal display apparatus, characterized in that: an upper layer of a transparent pixel electrode is used for coating an insulating film onto said transparent pixel electrode for two types of liquid crystal orientation control electrodes connected to two different potentials, and only one TFT array substrate side is used for controlling an oblique direction of a vertical alignment negative dielectric constant anisotropic liquid crystal molecule completely, without the need of installing a bump or slit electrode onto a substrate corresponding to said TFT array substrate for a liquid crystal alignment control.
2. An active matrix vertical alignment liquid crystal display apparatus, characterized in that: an upper layer of a slender slit transparent pixel electrode is used for installing an insulating film coated onto said transparent pixel electrode corresponding to a liquid crystal orientation control electrode for controlling a liquid crystal alignment, without the need of installing a bump or slit electrode onto a substrate corresponding to said TFT array substrate for a liquid crystal alignment control, and only one TFT array substrate side is used for controlling an oblique direction of a vertical alignment negative dielectric constant anisotropic liquid crystal molecule completely.
3. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein an upper layer of a transparent pixel electrode is used for installing an insulating film coated onto said transparent pixel electrode into two different types of liquid crystal orientation control electrodes connected to two different potentials, and one liquid crystal orientation control electrode is connected to the same potential of said transparent pixel electrode of said TFT array substrate.
4. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein an upper layer of a transparent pixel electrode is used for installing an insulating film coated onto said insulating film of said transparent pixel electrode and coupled with two types of liquid crystal orientation control electrodes of two different potentials, and said liquid crystal orientation control electrode at an end is coupled to a common electrode of a substrate with the same potential with respect to said TFT array substrate.
5. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said transparent pixel electrode upper layer is coated by an insulating film of said transparent pixel electrode and coupled to two types of liquid crystal orientation control electrodes of two different potentials, and said liquid crystal orientation control electrode at an end is coupled to a common electrode of a substrate with the same potential with respect to said TFT array substrate, and said liquid crystal orientation control electrode at another end is coupled to a pixel electrode with the same potential of said TFT array substrate.
6. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said transparent pixel electrode is coated by an insulating film of said transparent pixel electrode, and coupled to two types of liquid crystal orientation control electrodes of two different potentials, and said liquid crystal orientation control electrode at an end is coupled to a common electrode of a substrate with the same potential with respect to said TFT array substrate, and said liquid crystal orientation control electrode at another end is coupled to a pixel electrode with the same potential of said TFT array substrate, and also connected to an orientation control electrode with the same potential of said pixel electrode of said TFT array substrate, and having a closer potential to a substrate with respect to said TFT array substrate than said common electrode coupled to an orientation control electrode at another end.
7. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said transparent pixel electrode is coated by an insulating film of said transparent pixel electrode and coupled to two types of liquid crystal orientation control electrodes of two different potentials, and said liquid crystal orientation control electrode at an end is coupled to a common electrode of a substrate with the same potential with respect to said TFT array substrate, and said liquid crystal orientation control electrode at another end is coupled to a pixel electrode with the same potential of said TFT array substrate, and said transparent pixel electrode and said video signal line are bent with 90 degrees for more than one time at the position proximate to the center of said pixel electrode of said two different types of orientation control electrodes for aligning said scan lines in a direction of ±45 degrees.
8. The active matrix vertical alignment liquid crystal display apparatus of claim 2, wherein said upper layer of a slender slit transparent pixel electrode is formed for controlling a liquid crystal alignment, and coated by an insulating film of said transparent pixel electrode, and said liquid crystal orientation control electrode is coupled to a pixel electrode having the same potential as said TFT array substrate.
9. The active matrix vertical alignment liquid crystal display apparatus of claim 2, wherein said upper layer of a slender slit transparent pixel electrode is formed for controlling a liquid crystal alignment, and coated by an insulating film of said transparent pixel electrode, and said liquid crystal orientation control electrode is coupled to a pixel electrode having the same potential as said TFT array substrate, and said video signal line and said transparent pixel electrode are formed at said slender slit for controlling a liquid crystal alignment inside said transparent pixel electrode, and bent with 90 degrees the position proximate to the center of said pixel electrode of said liquid crystal orientation control electrode for aligning said scan lines in a direction of ±45 degrees.
10. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said transparent pixel electrode is coated by an insulating film of said transparent pixel electrode, and coupled to two types of liquid crystal orientation control electrodes of two different potentials, and said two types of orientation control electrodes are formed by the same electrode material and on the same layer.
11. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said insulating film coated onto said transparent pixel electrode installs two types of liquid crystal orientation control electrodes of two different potentials, and said two types of orientation control electrodes are formed by the same electrode material and on the same layer, and said liquid crystal orientation control electrode at an end is coupled to a transparent pixel electrode having the same potential of said TFT array substrate, and said liquid crystal orientation control electrode is closer to a substrate with respect to said TFT array substrate than said liquid crystal orientation control electrode at another end having a different potential.
12. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said insulating film coated onto said transparent pixel electrode installs two types of liquid crystal orientation control electrodes coupled to two different potentials, and said two types of liquid crystal orientation control electrodes are installed at different layers.
13. The active matrix vertical alignment liquid crystal display apparatus of claim 1, wherein said upper layer of said insulating film coated onto said transparent pixel electrode installs two types of liquid crystal orientation control electrodes of two different potentials, and said two types of liquid crystal orientation control electrodes are formed at different layers, and a liquid crystal orientation control electrode at an end is coupled to a transparent pixel electrode having the same potential of said TFT array substrate, and said liquid crystal orientation control electrode is closer to a substrate of said TFT array substrate than said liquid crystal orientation control electrode at another end connected to a different potential.
14. A method of fabricating MVA active matrix substrate, and said substrate constituting an active matrix display device, characterized in that: a photolithographic procedure is performed three times for the manufacture:
- (1) forming a gate electrode, a pixel electrode, a common electrode and a contact pad in said pixel electrode (wherein said photolithographic procedure using a halftone exposure method for the first time);
- (2) forming a separate thin film semiconductor layer component, and a contact hole (wherein said photolithographic procedure using a halftone exposure method for the second time);
- (3) forming a source electrode, a drain electrode and an orientation control electrode (wherein said photolithographic procedure using a general exposure method); such that after an ohmic contact layer of a channel portion of said thin film transistor is dry etched, a partial film of a passivation layer is formed by a silicon nitride film by using a mask deposition method (wherein said film is formed at a terminal portion other than those of a gate electrode, a source electrode and a common electrode).
15. A method of fabricating MVA active matrix substrate, and said substrate constituting an active matrix display device, characterized in that: a photolithographic procedure is performed three times for the manufacture:
- (1) forming a gate electrode, a pixel electrode and a contact pad in said pixel electrode (wherein said photolithographic procedure uses a halftone exposure method for the first time);
- (2) forming a separate thin film semiconductor layer component, and a contact hole (wherein said photolithographic procedure uses a halftone exposure method for the second time);
- (3) forming a source electrode, a drain electrode, an orientation control electrode and a common electrode (wherein said photolithographic procedure uses a general exposure method); such that after an ohmic contact layer of a channel portion of said thin film transistor is dry etched, a partial film of a passivation layer is formed by a silicon nitride film by using a mask deposition method (wherein said film is formed at a terminal portion other than those of a gate electrode, a source electrode and a common electrode).
16. A MVA active matrix liquid crystal display apparatus, manufactured by a manufacturing method of claim 14.
17. A MVA active matrix liquid crystal display apparatus, manufactured by a manufacturing method of claim 15, and characterized in that a basic unit pixel constitute an area of 2:1, and a video signal line (or a source electrode) is divided longitudinally into two, and said two divided pixel electrodes are coupled to each thin film transistor component respectively, and a source electrode of said two thin film transistor components is coupled to said video signal line that divides said pixel into two, and said two thin film transistor components are switched by a same scan line (or gate electrode), and said two divided pixel electrodes form a capacitor with different common electrode and insulating film aligned in parallel with said video signal wire, and said video signal wires are aligned in parallel on odd-numbered rows and even-numbered rows of said common electrode, and a voltage is applied to signals with different opposite polarities within a horizontal scan period (H period), and said video signal line in said two divided pixel electrodes is used for applying a voltage greater than an effective signal of large pixel electrode liquid crystal molecules on small pixel electrode liquid crystal molecules.
18. A method of fabricating an IPS active matrix substrate, and said substrate constituting an active matrix display device, characterized in that: a photolithographic procedure is performed for three times for the manufacture:
- (1) forming a gate electrode, a comb pixel electrode, a common electrode for shielding a video signal line (or a source electrode), a contact pad in said pixel electrode, and a video signal line for shielding said contact pad in common electrode (wherein said photolithographic procedure uses a halftone exposure method for the first time);
- (2) forming a separate thin film semiconductor layer component, and a contact hole (wherein said photolithographic procedure uses a halftone exposure method for the second time);
- (3) forming a source electrode (or video signal line), a drain electrode, a common electrode at the center of a pixel and a comb common electrode (wherein said third time of photolithographic procedure uses a halftone exposure method), such that after an ohmic contact layer of a channel portion of said thin film transistor is dry etched, a partial film of a passivation layer is formed by a silicon nitride film by using a mask deposition method (wherein said film is formed at a terminal portion other than those of a gate electrode, a source electrode and a common electrode).
19. A method of fabricating FFS active matrix substrate, and said substrate constituting an active matrix display device, characterized in that: said substrate is fabricated by applying a photolithographic procedure for three times:
- (1) forming a gate electrode, a pixel electrode and a contact pad in said pixel electrode (wherein a first time of applying said photolithographic procedure adopts a halftone exposure method);
- (2) forming a separate thin film semiconductor layer component, and a contact hole (wherein a second time of applying said photolithographic procedure adopts a halftone exposure method); and
- (3) forming a source electrode (or a video signal line), a drain electrode, a common electrode at the center of a pixel and a comb common electrode (wherein a third time of applying said photolithographic procedure adopts a halftone exposure method), such that after an ohmic contact layer of a channel portion of said thin film transistor is dry etched, a partial film of a passivation layer is formed by a silicon nitride film by using a mask deposition method (wherein said film is formed at a terminal portion other than those of a gate electrode, a source electrode and a common electrode).
20. A horizontal electric field active matrix liquid crystal display apparatus, manufactured by a method of claim 18.
21. A FFS active matrix liquid crystal display apparatus, manufactured by a method of claim 19, characterized in that: an upper layer of a pixel electrode at a position proximate to the center of a pixel installs a common electrode in parallel with a video signal line by an insulating film, and a signal voltage is applied to odd-numbered rows and even-numbered rows of said common electrode in a horizontal scan period (H period) and having opposite polarities with each other, and said polarities are opposite to the polarities of said video signal line within said horizontal scan period (H period, and said video signal line of said screen is divided into two at the middle of said display screen, and the signals at said upper and lower video signal line have the same polarity, and said common electrode disposed at the center of said pixel integrates said display screen from top to bottom as a whole.
Type: Application
Filed: May 3, 2007
Publication Date: Dec 20, 2007
Inventors: Sakae Tanaka (Mito City), Toshiyuki Samejima (Kodaira City)
Application Number: 11/743,749
International Classification: G02F 1/1337 (20060101);