Patents by Inventor Shou Nagao

Shou Nagao 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: 20140159045
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD?GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Application
    Filed: February 14, 2014
    Publication date: June 12, 2014
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 8665197
    Abstract: A pulse is input to first and second TFTs to turn ON the first and second TFTs so that the potential of a node a rises. When the potential of the node a reaches (VDD?VthN), the node ? enters a floating state. Accordingly, a third TFT then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the third TFT further rises due to an operation of capacitance as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the third TFT.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: March 4, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 8659532
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: February 25, 2014
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Publication number: 20130251091
    Abstract: A driver circuit of a display device, which includes TFTs of a single conductivity type and outputs an output signal with normal amplitude. A pulse is inputted to TFTs 101 and 104 to turn ON the TFTs and a potential of a node ? is raised. When the potential of the node ? reaches (VDD?VthN), the node ? becomes in a floating state. Accordingly, a TFT 105 is turned ON and a potential of an output node is raised as a clock signal becomes High level. On the other hand, a potential of a gate electrode of the TFT 105 is further raised due to an operation of a capacitance means 107 as the potential of the output node is raised, so that the potential of the gate electrode of the TFT 105 becomes higher than (VDD+VthN). Thus, the potential of the output node is raised to VDD without causing a voltage drop due to a threshold voltage of the TFT 105.
    Type: Application
    Filed: February 6, 2013
    Publication date: September 26, 2013
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shou Nagao, Yoshifumi Tanada, Yutaka Shionoiri, Hiroyuki Miyake
  • Publication number: 20130063328
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD?GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Application
    Filed: September 14, 2012
    Publication date: March 14, 2013
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Munehiro AZAMI, Shou NAGAO, Yoshifumi TANADA
  • Publication number: 20130057161
    Abstract: A pulse is input to first and second TFTs to turn ON the first and second TFTs so that the potential of a node ? rises. When the potential of the node ? reaches (VDD?VthN), the node ? enters a floating state. Accordingly, a third TFT then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the third TFT further rises due to an operation of capacitance as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the third TFT.
    Type: Application
    Filed: September 6, 2012
    Publication date: March 7, 2013
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 8284151
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: October 9, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 8264445
    Abstract: A drive circuit of a display device, which comprise only single conductive TFTs and in which amplitude of an output signal is normal, is provided. A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node á rises. When the potential of the node á reaches (VDD?VthN), the node á became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105. An output at the subsequent stage is then inputted to TFTs 102 and 103 to turn the TFTs 102 and 103 ON, while the potential of the node á drops down to turn the TFT 105 OFF.
    Type: Grant
    Filed: October 8, 2009
    Date of Patent: September 11, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Publication number: 20110149189
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Application
    Filed: March 3, 2011
    Publication date: June 23, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 7903079
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: March 8, 2011
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 7817170
    Abstract: The invention provides a driving method of a semiconductor display device in which generation of a pseudo contour can be suppressed while the operating frequency of a driver circuit is suppressed. Furthermore, the invention provides a driving method of a semiconductor display device in which generation of a pseudo contour can be suppressed while the decrease in image quality is suppressed. In a semiconductor display device including a plurality of pixels, tables each storing data for determining a subframe period for light emission among a plurality of subframe periods are provided for a plurality of arbitrary pixels among the plurality of pixels respectively. The table is stored in a memory.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: October 19, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Keisuke Miyagawa, Shou Nagao, Hisashi Ohtani
  • Patent number: 7710384
    Abstract: A drive circuit of a display device, which comprise only single conductive TFTs and in which amplitude of an output signal is normal, is provided. A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node á rises. When the potential of the node á reaches (VDD?VthN), the node á became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105. An output at the subsequent stage is then inputted to TFTs 102 and 103 to turn the TFTs 102 and 103 ON, while the potential of the node á drops down to turn the TFT 105 OFF.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: May 4, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Publication number: 20100073348
    Abstract: A drive circuit of a display device, which comprise only single conductive TFTs and in which amplitude of an output signal is normal, is provided. A pulse is inputted to TFTs 101 and 104 so that the TFTs would turn ON and then potential of a node á rises. When the potential of the node á reaches (VDD?VthN), the node á became in a floating state. Accordingly, a TFT 105 then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the TFT 105 further rises due to an operation of capacitance 107 as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the TFT 105. An output at the subsequent stage is then inputted to TFTs 102 and 103 to turn the TFTs 102 and 103 ON, while the potential of the node á drops down to turn the TFT 105 OFF.
    Type: Application
    Filed: October 8, 2009
    Publication date: March 25, 2010
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 7683860
    Abstract: The invention provides a display device with high image quality and high definition, a driving method thereof and an element substrate. Further, the invention provides a display device with improved degradation of a light emitting element, a driving method thereof and an element substrate. The display device of the invention has a first transistor, a second transistor, a third transistor, a light emitting element, a source driver, a first gate driver, and a second gate driver. A gate electrode of the first transistor is connected to a gate line, one of a source electrode and a drain electrode thereof is connected to a source line and the other is connected to a gate electrode of the third transistor. The light emitting element, the second transistor and the third transistor are connected in series between a first power source and a second power source.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: March 23, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shou Nagao, Hajime Kimura, Aya Anzai, Yu Yamazaki, Mitsuaki Osame, Yoshifumi Tanada
  • Patent number: 7683372
    Abstract: The present invention is to carry out stable doping and to prevent the drastic pressure change in a treatment chamber by reducing degasification of resist during adding impurities. In the present invention, the stability of the impurity ion injection can be ensured by reducing degasification of resist by reducing the area (resist area proportion, that is, the ratio of the area of resist to the whole area of a substrate) of resist pattern which is used depending on the conditions such as acceleration voltage or current density of a doping process.
    Type: Grant
    Filed: July 21, 2008
    Date of Patent: March 23, 2010
    Assignee: Semiconductor Energy Laboratory Co., Ltd
    Inventors: Hitomi Ushitani, Shou Nagao, Tomoyuki Iwabuchi
  • Publication number: 20090322716
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Application
    Filed: September 2, 2009
    Publication date: December 31, 2009
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Patent number: 7586478
    Abstract: There is provided a semiconductor device in which fabrication steps can be reduced by constructing a circuit using only TFTs of one conductivity type and in which a voltage amplitude of an output signal can be normally obtained. A capacitance (205) is provided between a gate and a source of a TFT (203) connected to an output node, and a circuit formed of TFTs (201) and (202) has a function to bring a node ? into a floating state. When the node ? is in the floating state, a potential of the node ? is caused higher than VDD by using gate-source capacitance coupling of the TFT (203) through the capacitance (205), thus an output signal having an amplitude of VDD-GND can be normally obtained without causing amplitude attenuation due to the threshold value of the TFT.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: September 8, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Munehiro Azami, Shou Nagao, Yoshifumi Tanada
  • Publication number: 20090189921
    Abstract: The invention provides a driving method of a semiconductor display device in which generation of a pseudo contour can be suppressed while the operating frequency of a driver circuit is suppressed. Furthermore, the invention provides a driving method of a semiconductor display device in which generation of a pseudo contour can be suppressed while the decrease in image quality is suppressed. In a semiconductor display device including a plurality of pixels, tables each storing data for determining a subframe period for light emission among a plurality of subframe periods are provided for a plurality of arbitrary pixels among the plurality of pixels respectively. The table is stored in a memory.
    Type: Application
    Filed: July 25, 2005
    Publication date: July 30, 2009
    Inventors: Keisuke Miyagawa, Shou Nagao, Hisashi Ohtani
  • Patent number: 7550790
    Abstract: A D/A conversion circuit with a small area is provided. In the D/A conversion circuit, according to a digital signal transmitted from address lines of an address decoder, one of four gradation voltage lines is selected. A circuit including two N-channel TFTs is connected in series to a circuit including two P-channel TFT, and a circuit including the circuits connected in series to each other is connected in parallel to each of the gradation voltage lines. Further, an arrangement of the circuit including the two N-channel TFTs and the circuit including the two P-channel TFTs is reversed for every gradation voltage line. By this, the crossings of wiring lines in the D/A conversion circuit becomes small and the area can be made small.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: June 23, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Mitsuaki Osame, Yukio Tanaka, Munehiro Azami, Naoko Yano, Shou Nagao
  • Patent number: 7544981
    Abstract: There is provided an active matrix type semiconductor display device which realizes low power consumption and high reliability. In the active matrix type semiconductor display device of the present invention, a counter electrode is divided into two, different potentials are applied to the two counter electrodes, respectively and inversion driving is carried out each other. Since a potential of an image signal can be made low by doing so, it is possible to lower a voltage necessary for operation of a driver circuit. As a result, it is possible to realize improvement of reliability of an element such as a TFT and reduction of consumed electric power. Moreover, since it is possible to lower a voltage of a timing pulse supplied by the driver circuit, a booster circuit can be omitted, and reduction of an area of the driver circuit can be realized.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: June 9, 2009
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yukio Tanaka, Shou Nagao