Patents by Inventor Yasushi Tomioka

Yasushi Tomioka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170363920
    Abstract: In a liquid crystal display device, a common electrode is formed on an organic passivation film, an interlayer insulating film is formed on the common electrode, a pixel electrode with a slit is formed on the interlayer insulating film, and a through hole is formed in the organic passivation film and the interlayer insulating film, so that the pixel electrode is connected to a source electrode of a TFT through the through hole. Further, the taper angle around the upper base of the through hole is smaller than the taper angle around the lower base. Thus, the alignment film material can easily flow into the through hole when the diameter of the through hole is reduced to connect the pixel and source electrodes, preventing display defects such as uneven brightness due to the absence of the alignment film or due to the alignment film irregularity around the through hole.
    Type: Application
    Filed: September 1, 2017
    Publication date: December 21, 2017
    Inventors: Yasushi TOMIOKA, Yosuke HYODO, Hidehiro SONODA, Noboru KUNIMATSU
  • Patent number: 9841633
    Abstract: In the step of curing a resin for bonding a TFT substrate and a counter substrate each having an alignment film that has been optically aligned by using UV-light, damage to the alignment film due to the UV-light can be prevented without using a light shielding mask. A UV-light absorption layer is formed between each black matrix on the counter substrate. The TFT and counter substrates are sealed at their periphery by a resin that is cured by UV-light radiated from the counter substrate side. Since the absorption layer has a high absorbability to UV-light at a wavelength of 300 nm or less that degrades the alignment film, damage to the alignment film due to the UV-light for curing the resin can be prevented. Thus, provision of a light shielding mask for shielding the UV-light for the display region can be saved.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: December 12, 2017
    Assignee: Japan Display Inc.
    Inventors: Noboru Kunimatsu, Yuko Matsumoto, Yasushi Tomioka, Masateru Morimoto, Atsuhiro Katayama
  • Patent number: 9841636
    Abstract: A high-definition and high-contrast liquid crystal display device having a high aperture ratio without light leakage around a columnar spacer is provided. The liquid crystal display device of a horizontal electric field type includes a TFT substrate with a pixel electrode and a common electrode, a color filter substrate with a color filter, a columnar spacer interposed between the substrates, and a liquid crystal layer arranged between the substrates. A liquid crystal alignment film formed between the substrates is a photo-alignment film. The columnar spacer, formed on the color filter substrate or the TFT substrate, has a wall-like shape and an inclined surface extending in a direction parallel to or perpendicular to a direction in which the liquid crystal is initially aligned.
    Type: Grant
    Filed: April 10, 2014
    Date of Patent: December 12, 2017
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Osamu Itou, Toshimasa Ishigaki, Hidehiro Sonoda, Yosuke Hyodo
  • Patent number: 9817288
    Abstract: A liquid crystal display device comprising a TFT substrate having pixels each including a common electrode formed on an organic passivation film, an interlayer insulating film formed so as to cover the common electrode, a pixel electrode having a slit and formed on the interlayer insulating film, a through-hole formed in the organic passivation film and the interlayer insulating film, and a source electrode electrically conducted to the pixel electrode via the through-hole. A taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees. The pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. This configuration facilitates the alignment film material to flow into the through-hole, thereby solving a thickness unevenness of the alignment film in vicinity of the through-hole.
    Type: Grant
    Filed: November 4, 2016
    Date of Patent: November 14, 2017
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Toshimasa Ishigaki, Hidehiro Sonoda, Sumito Ueta
  • Publication number: 20170322442
    Abstract: A liquid crystal display device includes: a TFT substrate having gate lines and data lines arranged thereon, the gate lines extending in a first direction and arranged in a second direction, the data lines extending in the second direction and arranged in the first direction; a counter substrate having a black matrix and a color filter; and liquid crystals put between the TFT substrate and the counter substrate. Columnar spacers are fainted on the counter substrate. Pedestals are formed on portions of the TFT substrate, the portions corresponding to the columnar spacers. A convex portion and a concave portion are present at the top end of the columnar spacer. The pedestal is formed corresponding to the concave portion. The concave portion is opened at the ends thereof and connected to the lateral side of the columnar spacer.
    Type: Application
    Filed: July 26, 2017
    Publication date: November 9, 2017
    Inventors: Yasushi TOMIOKA, Noboru KUNIMATSU, Yosuke HYODO, Toshiki KANEKO, Yuko MATSUMOTO
  • Patent number: 9785013
    Abstract: A liquid crystal display device includes a TFT substrate having a first alignment film and an opposing substrate having a second alignment film with liquid crystals sandwiched therebetween. One of the first and second alignment films, comprises a first polyimide produced via polyamide acid ester containing cyclobutane as a precursor and a second polyimide produced via polyamide acid as a precursor. The polyamide acid has a higher polarity than that of the polyamide acid ester. The one of the first and second alignment films is responsive to photo-alignment. A first side of the one of the first and second alignment films is adjacent to the liquid crystals, and a second side thereof is closer to one of the TFT substrate and the counter substrate than the first side. The first side contains more of the first polyimide and less of the second polyimide than the second side.
    Type: Grant
    Filed: September 23, 2015
    Date of Patent: October 10, 2017
    Assignees: Japan Display Inc., Panasonic Liquid Crystal Display Co., Ltd.
    Inventors: Noboru Kunimatsu, Chikae Matsui, Hidehiro Sonoda, Yuko Matsumoto, Shoichi Uchino, Masaki Matsumori, Yasushi Tomioka
  • Patent number: 9778520
    Abstract: In a liquid crystal display device, a common electrode is formed on an organic passivation film, an interlayer insulating film is formed on the common electrode, a pixel electrode with a slit is formed on the interlayer insulating film, and a through hole is formed in the organic passivation film and the interlayer insulating film, so that the pixel electrode is connected to a source electrode of a TFT through the through hole. Further, the taper angle around the upper base of the through hole is smaller than the taper angle around the lower base. Thus, the alignment film material can easily flow into the through hole when the diameter of the through hole is reduced to connect the pixel and source electrodes, preventing display defects such as uneven brightness due to the absence of the alignment film or due to the alignment film irregularity around the through hole.
    Type: Grant
    Filed: January 9, 2017
    Date of Patent: October 3, 2017
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Yosuke Hyodo, Hidehiro Sonoda, Noboru Kunimatsu
  • Patent number: 9746718
    Abstract: A liquid crystal display device includes: a TFT substrate having gate lines and data lines arranged thereon, the gate lines extending in a first direction and arranged in a second direction, the data lines extending in the second direction and arranged in the first direction; a counter substrate having a black matrix and a color filter; and liquid crystals put between the TFT substrate and the counter substrate. Columnar spacers are formed on the counter substrate. Pedestals are formed on portions of the TFT substrate, the portions corresponding to the columnar spacers. A convex portion and a concave portion are present at the top end of the columnar spacer. The pedestal is formed corresponding to the concave portion. The concave portion is opened at the ends thereof and connected to the lateral side of the columnar spacer.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: August 29, 2017
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Noboru Kunimatsu, Yosuke Hyodo, Toshiki Kaneko, Yuko Matsumoto
  • Patent number: 9703152
    Abstract: In an IPS mode liquid crystal display device, a counter electrode is formed flat on a first insulating film. A second insulating film is formed in the peripheral portion of the counter electrode. A third insulating film is formed so as to cover the counter electrode and the second insulating film. A pixel electrode is formed on the third insulating film. The second and third insulating films are present between the pixel electrode and the counter electrode in the periphery of the pixel. The third insulating film is present between the pixel electrode and the counter electrode in the portion other than the peripheral portion of the pixel. An electric field between the pixel electrode and the counter electrode is smaller in the periphery of the pixel than in the vicinity of the center of the pixel, to prevent the occurrence of a domain in the periphery of the pixel.
    Type: Grant
    Filed: August 13, 2014
    Date of Patent: July 11, 2017
    Assignee: Japan Display Inc.
    Inventors: Takeshi Sakai, Toshimasa Ishigaki, Yasushi Tomioka
  • Publication number: 20170146872
    Abstract: In a liquid crystal display device, a common electrode is formed on an organic passivation film, an interlayer insulating film is formed on the common electrode, a pixel electrode with a slit is formed on the interlayer insulating film, and a through hole is formed in the organic passivation film and the interlayer insulating film, so that the pixel electrode is connected to a source electrode of a TFT through the through hole. Further, the taper angle around the upper base of the through hole is smaller than the taper angle around the lower base. Thus, the alignment film material can easily flow into the through hole when the diameter of the through hole is reduced to connect the pixel and source electrodes, preventing display defects such as uneven brightness due to the absence of the alignment film or due to the alignment film irregularity around the through hole.
    Type: Application
    Filed: January 9, 2017
    Publication date: May 25, 2017
    Inventors: Yasushi TOMIOKA, Yosuke HYODO, Hidehiro SONODA, Noboru KUNIMATSU
  • Publication number: 20170137667
    Abstract: According to one embodiment, a varnish for a photo alignment film includes a first polyamic acid-based compound, which is a polyamic acid or a polyamic acid ester, in an organic solvent. The first polyamic acid-based compound has terminal skeletons containing no primary amino group.
    Type: Application
    Filed: November 9, 2016
    Publication date: May 18, 2017
    Applicant: Japan Display Inc.
    Inventors: Hidehiro SONODA, Yasushi TOMIOKA, Noboru KUNIMATSU, Takenori HIROTA
  • Publication number: 20170075179
    Abstract: A liquid crystal display device comprising a TFT substrate having pixels each including a common electrode formed on an organic passivation film, an interlayer insulating film formed so as to cover the common electrode, a pixel electrode having a slit and formed on the interlayer insulating film, a through-hole formed in the organic passivation film and the interlayer insulating film, and a source electrode electrically conducted to the pixel electrode via the through-hole. A taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees. The pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. This configuration facilitates the alignment film material to flow into the through-hole, thereby solving a thickness unevenness of the alignment film in vicinity of the through-hole.
    Type: Application
    Filed: November 4, 2016
    Publication date: March 16, 2017
    Inventors: Yasushi TOMIOKA, Toshimasa ISHIGAKI, Hidehiro SONODA, Sumito UETA
  • Patent number: 9575385
    Abstract: In a liquid crystal display device, a common electrode is formed on an organic passivation film, an interlayer insulating film is formed on the common electrode, a pixel electrode with a slit is formed on the interlayer insulating film, and a through hole is formed in the organic passivation film and the interlayer insulating film, so that the pixel electrode is connected to a source electrode of a TFT through the through hole. Further, the taper angle around the upper base of the through hole is smaller than the taper angle around the lower base. Thus, the alignment film material can easily flow into the through hole when the diameter of the through hole is reduced to connect the pixel and source electrodes, preventing display defects such as uneven brightness due to the absence of the alignment film or due to the alignment film irregularity around the through hole.
    Type: Grant
    Filed: July 18, 2016
    Date of Patent: February 21, 2017
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Yosuke Hyodo, Hidehiro Sonoda, Noboru Kunimatsu
  • Publication number: 20170023814
    Abstract: The present invention prevents the shaving of an alignment film caused by a columnar spacer in a liquid crystal display device of an IPS method using photo-alignment. A plinth higher than a pixel electrode is formed at a part where a columnar spacer formed over a counter substrate touches a TFT substrate. When an alignment film of a double-layered structure is applied over the pixel electrode and the plinth, the thickness of the alignment film over the plinth reduces by a leveling effect. When photo-alignment is applied in the state, a photodegraded upper alignment film over the plinth disappears and a lower alignment film having a high mechanical strength remains. As a result, it is possible to prevent the shaving of the alignment film.
    Type: Application
    Filed: October 4, 2016
    Publication date: January 26, 2017
    Inventors: Noboru KUNIMATSU, Masaki MATSUMORI, Hidehiro SONODA, Yasushi TOMIOKA, Toshiki KANEKO
  • Publication number: 20170003537
    Abstract: There is provided a display device including a first base material, a second base material, an optical layer placed between the first base material and the second base material, and a first retardation layer placed in contact with the first base material, wherein the first base material and the second base material are formed from a polyimide, and the first retardation layer and the second retardation layer are liquid crystal layers which are vertically aligned. Providing the first and second retardation layers in contact with the first and second base materials make it possible to achieve a reduction in the thickness of the display device.
    Type: Application
    Filed: June 27, 2016
    Publication date: January 5, 2017
    Inventors: Shinichiro OKA, Toshinari SASAKI, Yasushi TOMIOKA
  • Publication number: 20160377925
    Abstract: A liquid crystal display is provided which is capable of reducing the occurrence of defective display due to variations in the initial alignment direction of a liquid crystal alignment control film in a liquid crystal display of an IPS scheme, realizing the stable liquid crystal alignment, providing excellent mass productivity, and having high image quality with a higher contrast ratio. The liquid crystal display has a liquid crystal layer disposed between a pair of substrates, at least one of the substrates being transparent, and an alignment control film formed between the liquid crystal layer and the substrate. At least one of the alignment control films 109 comprises photoreactive polyimide and/or polyamic acid provided with an alignment control ability by irradiation of substantially linearly polarized light.
    Type: Application
    Filed: June 27, 2016
    Publication date: December 29, 2016
    Inventors: Yasushi TOMIOKA, Hidetoshi ABE, Katsumi KONDO
  • Publication number: 20160377926
    Abstract: Various layer separation states are generated by the combination of a polyamide acid ester and a polyamide acid and a long residual image characteristic cannot be further improved merely by combining them. A liquid crystal display device comprises a substrate, a liquid crystal layer, and an orientation film placed between the substrate and the liquid crystal layer. The orientation film comprises a polyimide precursor having two or more components. In the polyimide precursor, an octanol-water partition coefficient is defined as log P and the difference in log P (? log P) between the two components having most distant log Ps is set so as to fall within a prescribed range.
    Type: Application
    Filed: September 13, 2016
    Publication date: December 29, 2016
    Inventors: Masaki MATSUMORI, Shuji IMAZEKI, Yasushi TOMIOKA, Noboru KUNIMATSU
  • Patent number: 9523897
    Abstract: To take measures against the phenomenon of difficulty for the orientation film material to flow into the through-hole when the diameter of through-holes which connects the pixel electrode and the source electrode becomes small. An interlayer insulating film 109 made of SiN is formed on a counter electrode, and a pixel electrode 110 having a slit 1101 is formed on the interlayer insulating film 109. A through-hole 111 which connects the pixel electrode 110 and the source electrode of a TFT has a large opening on the upper side, a small opening on the lower side, and an inner wall extending between the large opening and the small opening. The pixel electrode 110 covers the through-hole 111 on an inner side of the pixel of the through-hole 111 but does not cover a periphery of the large opening of the through-hole on an outer side of the through-hole 111.
    Type: Grant
    Filed: November 17, 2014
    Date of Patent: December 20, 2016
    Assignee: Japan Display Inc.
    Inventors: Yosuke Hyodo, Yasushi Tomioka, Noboru Kunimatsu, Hidehiro Sonoda, Yasuo Imanishi, Takenori Hirota
  • Patent number: 9519196
    Abstract: To prevent a phenomenon that an alignment film material is difficult to flow into the through-hole where a diameter of a through-hole for connecting between a pixel electrode and a source electrode is reduced. A liquid crystal display device comprising a TFT substrate having pixels each including a common electrode formed on an organic passivation film, an interlayer insulating film formed so as to cover the common electrode, a pixel electrode having a slit and formed on the interlayer insulating film, a through-hole formed in the organic passivation film and the interlayer insulating film, and a source electrode electrically conducted to the pixel electrode via the through-hole. A taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees. The pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole.
    Type: Grant
    Filed: December 9, 2014
    Date of Patent: December 13, 2016
    Assignee: Japan Display Inc.
    Inventors: Yasushi Tomioka, Toshimasa Ishigaki, Hidehiro Sonoda, Sumito Ueta
  • Publication number: 20160357078
    Abstract: A liquid crystal display device includes a TFT substrate, a CF substrate, and a liquid crystal interposed between the TFT substrate and the CF substrate, and drives the liquid crystal in a horizontal electric field. The TFT substrate includes a recess, and the CF substrate includes a columnar protrusion. The protrusion of the CF substrate is fitted to the recess of the TFT substrate so as to function as a stopper for preventing a positional gap between the TFT substrate and the CF substrate.
    Type: Application
    Filed: August 16, 2016
    Publication date: December 8, 2016
    Inventors: Yasushi TOMIOKA, Takato HIRATSUKA, Osamu ITOU