News Column

Patent Application Titled "Liquid Crystal Display Apparatus" Published Online

September 4, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors NOMURA, Yasuhiro (Tokyo, JP); IWAMOTO, Yoshihisa (Tokyo, JP), filed on February 12, 2014, was made available online on August 21, 2014.

The assignee for this patent application is Stanley Electric Co., Ltd.

Reporters obtained the following quote from the background information supplied by the inventors: "The present invention relates to a vertical alignment liquid crystal display apparatus which is driven by multiplex driving.

"A liquid crystal display apparatus is broadly used as an information display unit in various electronic devices for consumer or automobile use. In General, a liquid crystal display apparatus is configured by disposing a liquid crystal layer made of a liquid crystal material between two substrates that are placed opposite each other with a gap of roughly several micrometers. As one type of this kind of liquid crystal display apparatus, a vertical alignment liquid crystal display apparatus is known. For example, Japanese Patent Laid-Open No. 2012-93578 according to a patent application by the applicant of this application discloses a liquid crystal display apparatus configured so that the pixel edges of the respective pixels include line segments that are obliquely crossed relative to the direction of the orientation process. According to this precedent, it is possible to obtain a liquid crystal display apparatus that homogenizes the light leakage near the edges of the respective pixels when the apparatus is observed from an anti-viewing direction, and thus improves the display quality. Further, it has also been verified that the liquid crystal display apparatus of this precedent is capable of homogenizing the light leakage even in a case where the ambient temperature becomes relatively high, thereby maintaining the display quality. Furthermore, in the liquid crystal display apparatus of the precedent, it is only necessary to form at least one of the electrode edges of the electrodes respectively provided to the upper and lower substrates into a periodically bending shape, thereby resulting in the additional advantage of making it possible to align the direction of the orientation process to the up-down direction or left-right direction of the liquid crystal display apparatus, which is the generally preferred direction.

"The liquid crystal display apparatus of the precedent described above forms the electrode edges in the planar view of the respective electrodes of one substrate into periodically bending shapes, and forms the respective electrodes of the other substrate into stripe shapes in the planar view, establishing each location where both electrodes overlap as a pixel. Specifically, the respective electrodes of one substrate of the liquid crystal display apparatus of the precedent are disposed so that the bending apex portions of these electrode edges overlap with the gaps between the respective electrodes of the other substrate. As a result, the bending apex portion is disposed between two adjacent pixels.

"Nevertheless, in a case where a configuration wherein the bending apex portion is disposed between two adjacent pixels is adopted, high accuracy is required in the alignment process of the two substrates, resulting in the disadvantage of causing a decrease in yield as well as a decrease in production efficiency. This disadvantage becomes quite significant in a case where an attempt is made to increase the aperture ratio by further decreasing the distance between the electrodes."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "An object of a specific mode of the present invention which relates to a vertical alignment liquid crystal display apparatus driven by multiplex driving, is to increase the yield and production efficiency while maintaining the effectiveness of improving the display quality.

"The liquid crystal display apparatus according to a specific mode of the present invention comprises (a) a first substrate and a second substrate placed opposite each other, (b) a first electrode provided on one surface of the first substrate and which extends in a first direction, a second electrode provided on one surface of the second substrate and which extends in a second direction that intersects to the first direction, and (d) a mono-domain vertical alignment type liquid crystal layer with a pretilt angle of less than 90.degree., provided between one surface of the first substrate and one surface of the second substrate, (e) wherein a pixel is configured in a region where the first electrode and the second electrode intersect, (f) an orientation process is performed in a direction perpendicular to the second direction on at least one of the first substrate and the second substrate, (g) an electrode edge of at least one side of the second electrode is of a shape that includes lines or curves that are obliquely crossed relative to the first direction and periodically bend back, (h) the pixel edges of the pixel are demarcated, including the lines or curves that are obliquely crossed, and (i) all change points where a plurality of the lines or curves of the electrode edge of the second electrode interconnects are disposed so that they are superimposed in the planar view with the first electrode.

"According to the foregoing configuration, since the pixel edges are demarcated on including the line segments that are obliquely crossed relative to the direction of the alignment treatment, it is possible to homogenize the light leakage near the edges of the respective pixels on observing the liquid crystal display apparatus from an anti-viewing direction, and improve the display quality. Further, the change point of the electrode edge of the second electrode (for example, the bending point where the lines connect) is set to a position that is superimposed with the first electrode, thereby eliminating the need for high accuracy in the alignment of the first substrate and the second substrate and making it possible to improve the yield as well as production efficiency.

"In the above described liquid crystal display apparatus, the change point is preferably disposed at the center between the electrode edges of both sides of the first electrode, for example. The term 'center' here refers to an intermediate point between the first element and the second element, permitting a range of .+-.5% with respect to the intermediate point taking into consideration the manufacturing tolerance.

"As a result, a pixel edge of a horizontally or vertically symmetrical shape is obtained.

"In the above described liquid crystal display apparatus, the change point is preferably disposed so that it is biased toward the side near the electrode edge of either one side of the first electrode, for example.

"As a result, the margin of the alignment of the first substrate and the second substrate is further increased. Further, an effect of further homogenizing the orientation state of the liquid crystal layer is achieved.

"In the above described liquid crystal display apparatus, the obliquely crossing lines are preferably disposed at an angle greater than 0.degree. and less than or equal to 15.degree. using the second direction as standard.

"As a result, it is possible to visually recognize the shape of the pixel edge as close to that of a rectangle.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a schematic cross section showing the structure of the liquid crystal display apparatus according to one embodiment of the present invention.

"FIG. 2 is a schematic plan view showing an example of the electrode structure.

"FIG. 3 is a schematic plan view showing other example of the electrode structure.

"FIG. 4 is a schematic plan view showing other example of the electrode structure.

"FIG. 5 is a schematic plan view showing other example of the electrode structure.

"FIG. 6 is a schematic plan view showing other example of the electrode structure.

"FIG. 7 is a schematic plan view showing other example of the electrode structure.

"FIG. 8 is a schematic plan view showing an example of a modified electrode structure.

"FIG. 9A is a diagram showing the aligned texture during the bright display state of the liquid crystal display apparatus of an execution example.

"FIG. 9B is a diagram showing the aligned texture during the bright display state of the liquid crystal display apparatus of another execution example.

"FIG. 9C is a diagram showing the aligned texture during the bright display state of the liquid crystal display apparatus of a comparison example.

"FIG. 10 is a schematic plan view showing a modified configuration of the electrode edges."

For more information, see this patent application: NOMURA, Yasuhiro; IWAMOTO, Yoshihisa. Liquid Crystal Display Apparatus. Filed February 12, 2014 and posted August 21, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3997&p=80&f=G&l=50&d=PG01&S1=20140814.PD.&OS=PD/20140814&RS=PD/20140814

Keywords for this news article include: Stanley Electric Co. Ltd.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


For more stories covering the world of technology, please see HispanicBusiness' Tech Channel



Source: Politics & Government Week


Story Tools






HispanicBusiness.com Facebook Linkedin Twitter RSS Feed Email Alerts & Newsletters