This application is based upon and claims the benefit of priority from a prior Taiwanese Patent Application No. 097111653, filed on Mar. 31, 2008, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The invention relates to liquid crystal display (LCD) devices, and in particular to single layer color cholesteric liquid crystal display devices and fabrication methods thereof.
2. Description of the Related Art
Liquid crystal display (LCD) devices have many advantages such as a smaller size, lighter weight and lower power consumption, and are applicable in a variety of electronic and communication devices including notebook computers, personal digital assistants (PDA), mobile phones and the like due to its lighter weight, thinner profile, and portability. Conventional reflective memorable color liquid crystal display devices are widely applicable in electronic books, electronic papers, and the likes. The structures and fabrication methods of conventional cholesteric liquid crystal display devices use a tri-layered red (R), green (G), and blue (B) pixel stacked structure corresponding to various different driving methods. However, stacking tri-layered R, G, and B pixels may result in optical aberration and misalignment during fabrication. Moreover, the tri-layered R, G, and B liquid crystal layer stacked structure are so complicated that layout of electrodes is difficult to design and an LCD panel using the stacked structure has a rigid port, resulting in an intricate fabrication process and high fabrication costs.
Accordingly, the use of single layer color cholesteric liquid crystal display devices and fabrication methods thereof can effectively ameliorate optical aberration, simplify the fabrication process, and reduce fabrication costs. Particularly, the device is applicable to the field of color flexible LCD devices. U.S. Pat. No. 5,825,451, the entirety of which is hereby incorporated by reference, discloses a single layer color cholesteric LCD device using a combination of light decomposable/polymerizable chiral agents and a single layer cholesteric LC structure. The single layer color cholesteric LCD device is illuminated by a UV light disrupting or reducing contents of chiral agent at a single region to achieve colorizing of a single layer cholesteric LCD device. However, the single layer color cholesteric LCD device is easily affected by ambient light deteriorating display stability thereof.
U.S. Pat. No. 6,741,321, the entirety of which is hereby incorporated by reference, discloses an LCD device using a single LC layer and a double substrate assembly process. Different color LC materials are respectively injected into LC channels during fabrication. However, the single layer LCD assembly is not sealed enough such that overflow occurs between the adjacent LC channels resulting in color mixing and color saturation.
The features and aspects of the invention are related to single layer color cholesteric liquid crystal display devices and fabrication methods thereof. A bank portion and a base portion of the first substrate are optionally designed as a continuous unified structure, creating different length liquid crystal (LC) channels. An adhesion layer is optionally formed on another opposing substrate or the bank portion. The two opposing substrate are assembled. The assembled structure is sequentially cut, injected red, green, and blue LC, and sealed to prevent color mixing and reduce color saturation.
Embodiments of the invention provide a color cholesteric liquid crystal display device, comprising: a first substrate with a base portion and a periodic protruding bank portion; a second substrate opposing the first substrate to create a plurality of color sub-pixel channels; and a plurality of color cholesteric liquid crystals respectively filled in each of the color sub-pixel channels, wherein the base portion and the periodic protruding bank portion are a continuous unified structure.
Embodiments of the invention also provide a fabrication method for a color cholesteric liquid crystal display device, comprising: providing a first substrate; forming a patterning mask layer on the first substrate; etching the first substrate to create a base portion and a periodic protruding bank portion; forming a first conductive layer on the first substrate; removing the mask layer and the first conductive layer thereon, leaving a first electrode on the base portion along a first direction; providing a second substrate with a second electrode along a second direction; assembling the first substrate and the second substrate to adhere the periodic protruding bank portion to the second substrate and divide a plurality of color sub-pixel channels; and sequentially injecting a plurality of color cholesteric liquid crystals in the corresponding color sub-pixel channels and sealing each of the color sub-pixel channels with a sealant material.
Embodiments of the invention further provide a fabrication method for a color cholesteric liquid crystal display device, comprising: providing a first substrate; forming a thin-film layer on the first substrate; imprinting the first substrate with a template to create a base portion and a periodic protruding bank portion; depositing a first conductive layer on the first substrate; removing the thin-film layer on the bank portion and the first conductive layer on the thin-film layer, leaving a first electrode on the base portion along a first direction; providing a second substrate with a second electrode along a second direction; assembling the first substrate and the second substrate to adhere the periodic protruding bank portion to the second substrate and divide a plurality of color sub-pixel channels; and sequentially injecting a plurality of color cholesteric liquid crystals in the corresponding color sub-pixel channels and sealing each of the color sub-pixel channels with a sealant material.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
Subsequently, preparation of a second substrate structure (such as an upper substrate structure) is performed including providing a second substrate (step S220) and forming a patterned second electrode along the second direction on the second substrate (step S222). An adhesion layer is formed overlying the second substrate (step S226).
The first and second substrate structures are assembled opposed to each other with a gap interposed therebetween (step S230). The patterned bank portions and the adhesion layer are tightly combined to prevent mixtures of color LCs between adjacent LC channels from overflowing. A first color cholesteric LC is filled in a first stripe LC channel and then sealed (step S240). The assembly structure is cut to expose a second stripe LC channel (step S250). A second color cholesteric LC is filled in the second stripe LC channel and then sealed (step S260). The assembly structure is cut to expose a third stripe LC channel (step S270). A third color cholesteric LC is filled in the third stripe LC channel and then sealed (step S280). After all the three color cholesteric LCs are filled and sealed, fabrication of the single layer color cholesteric LCD device is completed (step S290).
According to another embodiment of the invention, preparation of another first substrate structure (such as a lower substrate structure) is optionally or alternatively performed including providing a first substrate (step S310) and forming a thin-film layer, such as photoresist, on the first substrate (step S312). The thin-film layer and the first substrate are imprinted by a template to create a protruding bank structure on the surface of the first substrate (step S314). The bank structure includes a base portion and a periodic protruding bank portion. Next, a conductive layer, serving as a first electrode, is blankly formed on the first substrate (step S316). The thin film layer and part of the conductive layer on the bank portion are removed (step S318), thereby leaving a first electrode along a first direction on the first substrate, as shown in
According to another embodiment of the invention, if the first substrate is adhesive, formation of the adhesion layer on the second substrate (step S226) can be omitted. The first and second substrate can thus be tightly combined.
Next, referring to
Referring to
According to another embodiment of the invention, a patterned adhesion layer 475 can be selectively formed on the second substrate 450, as shown in
According to another embodiment of the invention, if the first substrate 410 is adhesive, formation of the adhesion layer on the second substrate 450 can be omitted. The bank portions of the first substrate are tightly combined with the second substrate, as shown in
Next, referring to
Referring to
According to another embodiment of the invention, a patterned adhesion layer 575 can be selectively formed on the second substrate 550, as shown in
According to another embodiment of the invention, if the first substrate 510 is adhesive, formation of the adhesion layer on the second substrate 550 can be omitted. The bank portions of the first substrate are tightly combined with the second substrate.
According to another embodiment of the invention, a patterned adhesion layer 475 corresponding the periodic bank portions can be optionally disposed between the bank portions 412 of the first substrate and the second substrate 450 such that the adhesion layer is tightly adhered so as to prevent LC overflow between adjacent LC channels, as shown in
According to another embodiment of the invention, if the bank portions 412 of the first substrate are adhesive, formation of the adhesion layer on the second substrate 450 can be omitted. The bank portions of the first substrate are tightly combined with the second substrate.
Referring to
According to another embodiment of the invention, a patterned adhesion layer 575 corresponding the periodic bank portions can be optionally disposed between the bank portions 512 of the first substrate and the second substrate 550 such that the adhesion layer is tightly adhered so as to prevent LC overflow between adjacent LC channels, as shown in
According to another embodiment of the invention, if the bank portions 512 of the first substrate are adhesive, formation of the adhesion layer on the second substrate 550 can be omitted. The bank portions of the first substrate are tightly combined with the second substrate.
Referring to
Referring to
While the invention has been described by way of example and in terms of the several embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Number | Date | Country | Kind |
---|---|---|---|
97111653 A | Mar 2008 | TW | national |
Number | Name | Date | Kind |
---|---|---|---|
4090501 | Chaitin | May 1978 | A |
4281902 | Kmetz et al. | Aug 1981 | A |
4451122 | Oh et al. | May 1984 | A |
4744639 | Tsuboyama | May 1988 | A |
4805188 | Parker | Feb 1989 | A |
4834500 | Hilsum et al. | May 1989 | A |
4877307 | Kalmanash | Oct 1989 | A |
5096520 | Faris | Mar 1992 | A |
5172256 | Sethofer et al. | Dec 1992 | A |
5189534 | McDonnell et al. | Feb 1993 | A |
5221982 | Faris | Jun 1993 | A |
5268782 | Wenz et al. | Dec 1993 | A |
5399390 | Akins | Mar 1995 | A |
5400610 | Macedo | Mar 1995 | A |
5541745 | Fergason | Jul 1996 | A |
5599412 | Faris | Feb 1997 | A |
5692226 | Hall | Nov 1997 | A |
5808594 | Tsuboyama et al. | Sep 1998 | A |
5808794 | Weber et al. | Sep 1998 | A |
5822021 | Johnson et al. | Oct 1998 | A |
5825451 | Ma et al. | Oct 1998 | A |
5933205 | Yamazaki et al. | Aug 1999 | A |
5942154 | Kim et al. | Aug 1999 | A |
6088159 | Weber et al. | Jul 2000 | A |
6285434 | Ma et al. | Sep 2001 | B1 |
6331884 | Masazumi et al. | Dec 2001 | B1 |
RE37509 | Bradshaw et al. | Jan 2002 | E |
6404789 | Kopp et al. | Jun 2002 | B1 |
6411635 | Kopp et al. | Jun 2002 | B1 |
6416768 | Ravaux et al. | Jul 2002 | B1 |
6424387 | Sato et al. | Jul 2002 | B2 |
6678297 | Kopp et al. | Jan 2004 | B2 |
6741321 | Jeong et al. | May 2004 | B2 |
6761066 | Rait | Jul 2004 | B2 |
6821249 | Casscells, III et al. | Nov 2004 | B2 |
6833892 | Kamijo | Dec 2004 | B2 |
6879362 | Kawabata | Apr 2005 | B2 |
6909478 | Ichihashi et al. | Jun 2005 | B2 |
7012365 | Adachi et al. | Mar 2006 | B2 |
7067985 | Adachi | Jun 2006 | B2 |
7106402 | Suzuki et al. | Sep 2006 | B2 |
20010036212 | Kopp et al. | Nov 2001 | A1 |
20020047965 | Suzuki et al. | Apr 2002 | A1 |
20020093284 | Adachi et al. | Jul 2002 | A1 |
20020097357 | Huang et al. | Jul 2002 | A1 |
20020130993 | Ichihashi et al. | Sep 2002 | A1 |
20020157464 | Rait | Oct 2002 | A1 |
20020167630 | Fujieda et al. | Nov 2002 | A1 |
20030025865 | Takatori et al. | Feb 2003 | A1 |
20030090607 | Kamijo | May 2003 | A1 |
20030092975 | Casscells, III et al. | May 2003 | A1 |
20030107538 | Asao et al. | Jun 2003 | A1 |
20030137625 | Okazaki et al. | Jul 2003 | A1 |
20030137632 | Kawabata | Jul 2003 | A1 |
20030154784 | Rait | Aug 2003 | A1 |
20030160923 | Ma | Aug 2003 | A1 |
20030214617 | Bierhuizen et al. | Nov 2003 | A1 |
20040011995 | Faris | Jan 2004 | A1 |
20040051445 | Adachi | Mar 2004 | A1 |
20040119926 | Chung | Jun 2004 | A1 |
20040189167 | Adachi et al. | Sep 2004 | A1 |
20040222960 | Suzuki et al. | Nov 2004 | A1 |
20040223098 | Nose et al. | Nov 2004 | A1 |
20040246221 | Izumi | Dec 2004 | A1 |
20040257537 | Bierhuizen et al. | Dec 2004 | A1 |
20050068279 | Hirota et al. | Mar 2005 | A1 |
20050099575 | Liang | May 2005 | A1 |
20060050204 | Kim et al. | Mar 2006 | A1 |
20060119782 | Sha et al. | Jun 2006 | A1 |
20060119936 | Ockenfuss | Jun 2006 | A1 |
20060124897 | Shingai et al. | Jun 2006 | A1 |
20060158096 | Adachi et al. | Jul 2006 | A1 |
20060176257 | Wang et al. | Aug 2006 | A1 |
20060176258 | Sha et al. | Aug 2006 | A1 |
20060187520 | Bierhuizen | Aug 2006 | A1 |
20060262246 | Stephenson, III | Nov 2006 | A1 |
20060262247 | Stephenson, III et al. | Nov 2006 | A1 |
20070046794 | He et al. | Mar 2007 | A1 |
20070047037 | Yoshizawa et al. | Mar 2007 | A1 |
20080252821 | Liao et al. | Oct 2008 | A1 |
Number | Date | Country | |
---|---|---|---|
20090244442 A1 | Oct 2009 | US |