Patents by Inventor Tetsuo Asaba

Tetsuo Asaba 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).

  • Patent number: 7888715
    Abstract: A complementary metal-oxide semiconductor (CMOS) active pixel sensor includes a photodiode, a transfer transistor with a coupled gate, a reset transistor and a signal transfer circuit, where the photodiode generates electric charges in response to incident light, the transfer transistor transfers the electric charges integrated in the photodiode to a floating diffusion node, wherein the transfer transistor has a first transfer gate and a second transfer gate, and the first and second transfer gates have a coupled gate structure, the reset transistor resets a potential level of the floating diffusion node by a given voltage level, the signal transfer circuit transfers the potential level of the floating diffusion node to an internal circuit in response to a selection signal, and the CMOS active pixel sensor with the coupled gate may increase a capacity of the photodiode and reduce an image lag by using a voltage coupling effect of the coupled gate.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: February 15, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jung-Chak Ahn, Tetsuo Asaba, Young-Chan Kim
  • Patent number: 7750281
    Abstract: An image sensor includes a pixel with a drive transistor and a select transistor. The drive transistor is driven according to a voltage at a floating diffusion node. The select transistor is coupled in series with the drive transistor for being turned on when the pixel is selected. The image sensor also includes a current mirror unit having first and second branches conducting mirrored currents. The first branch is coupled to the drive transistor, and the second branch is coupled to the select transistor at an output node of the pixel. With such biasing by the current mirror, gain drop in the drive transistor is minimized.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: July 6, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tetsuo Asaba, Jung-Chak Ahn
  • Patent number: 7679112
    Abstract: Color image sensors include pixels having varying color characteristics. One of the pixels is a cyan-type pixel, which includes primary and secondary photodetectors therein. The primary photodetector extends adjacent a portion of a surface of a semiconductor substrate that is configured to receive visible light incident thereon. The secondary photodetector is buried in the semiconductor substrate. The secondary photodetector is configured to receive visible light that has passed through the primary photodetector.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: March 16, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Tetsuo Asaba
  • Patent number: 7652707
    Abstract: A pixel circuit of an image sensor includes a floating diffusion node and a reset transistor. The reset transistor is coupled between the floating diffusion node and a reset control signal node of another pixel circuit of the image sensor. A voltage applied on the reset control signal node of the other pixel circuit is a reset voltage transmitted to the floating diffusion node via the reset transistor.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: January 26, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-Chan Kim, Tetsuo Asaba, Yi-Tae Kim
  • Publication number: 20090189057
    Abstract: An image sensor includes a pixel with a drive transistor and a select transistor. The drive transistor is driven according to a voltage at a floating diffusion node. The select transistor is coupled in series with the drive transistor for being turned on when the pixel is selected. The image sensor also includes a current mirror unit having first and second branches conducting mirrored currents. The first branch is coupled to the drive transistor, and the second branch is coupled to the select transistor at an output node of the pixel. With such biasing by the current mirror, gain drop in the drive transistor is minimized.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 30, 2009
    Inventors: Tetsuo Asaba, Jung-Chak Ahn
  • Patent number: 7521661
    Abstract: An image sensor includes a set of at least two pixels each sensing light of a same color coupled to a signal converter. A driver simultaneously turns on a respective switching element for transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a moving image. Alternatively, the driver separately turns on the respective switching element for sequentially transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a still image.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: April 21, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Tetsuo Asaba
  • Patent number: 7521659
    Abstract: A solid-state image-sensing device includes a pixel array and an averaging unit. The pixel array includes a matrix of pixels and includes a respective output line for each of a plurality of pixel groupings such as for each column of pixels. The averaging unit receives respective signals from first and second output lines of the pixel array to generate a pulse width signal that indicates an average of such respective signals. A respective signal of the first output line is generated from combining photocurrents from a first set of at least two pixels sensing a same first color in the pixel array.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: April 21, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tetsuo Asaba, Su-Hun Lim
  • Patent number: 7508429
    Abstract: Provided are an improved solid-state image-sensing device for averaging sub-sampled analog signals and a method for driving the same. The solid-state image-sensing device receives a video signal from each pixel column and converts the video signal into a digital signal while a switch for averaging is turned off when the solid-state image-sensing device captures a still image. When the solid-state image-sensing device photographs a moving picture, one of two CDS circuits receives a signal corresponding to an average of video signals of columns having the same color pixel and converts the signal into a digital signal using the switch turned on.
    Type: Grant
    Filed: June 21, 2005
    Date of Patent: March 24, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Su-hun Lim, Tetsuo Asaba
  • Publication number: 20080224191
    Abstract: An image pickup device includes an active pixel sensor (APS), a row driver, and a leakage current breaker. The active pixel sensor includes an array of a plurality of pixels. The row driver selects at least one pixel to be activated to output signals. The leakage current breaker decreases the leakage current through the unselected pixels by applying a leakage current breaker voltage at the bit lines of the APS array.
    Type: Application
    Filed: March 5, 2008
    Publication date: September 18, 2008
    Inventors: Jung-Chak Ahn, Yi-Tae Kim, Kyung-Ho Lee, Hyuck-In Kwon, Ju-Hyun Ko, Tetsuo Asaba, Jong-Jin Lee, Su-Hun Lim, Jung-Yeon Kim, Se-Young Kim, Sung-In Hwang
  • Patent number: 7414233
    Abstract: A pixel circuit of an image sensor includes a photo-converting unit such as a photo-diode for generating charge from incident light. The pixel circuit also includes a charge storing capacitor for storing the charge generated by the photo-converting unit. The pixel circuit further includes a floating diffusion node that receives the charge from the charge storing unit after being reset. Thus, an image signal VSIG is generated after a reset signal VRES is generated from the pixel circuit.
    Type: Grant
    Filed: June 19, 2006
    Date of Patent: August 19, 2008
    Assignee: Samsung Electronic Co., Ltd.
    Inventor: Tetsuo Asaba
  • Publication number: 20080179641
    Abstract: Color image sensors include pixels having varying color characteristics. One of the pixels is a cyan-type pixel, which includes primary and secondary photodetectors therein. The primary photodetector extends adjacent a portion of a surface of a semiconductor substrate that is configured to receive visible light incident thereon. The secondary photodetector is buried in the semiconductor substrate. The secondary photodetector is configured to receive visible light that has passed through the primary photodetector.
    Type: Application
    Filed: October 31, 2007
    Publication date: July 31, 2008
    Inventor: Tetsuo Asaba
  • Publication number: 20080001067
    Abstract: A solid-state image-sensing device includes a pixel array and an averaging unit. The pixel array includes a matrix of pixels and includes a respective output line for each of a plurality of pixel groupings such as for each column of pixels. The averaging unit receives respective signals from first and second output lines of the pixel array to generate a pulse width signal that indicates an average of such respective signals. A respective signal of the first output line is generated from combining photocurrents from a first set of at least two pixels sensing a same first color in the pixel array.
    Type: Application
    Filed: July 5, 2007
    Publication date: January 3, 2008
    Inventors: Tetsuo Asaba, Su-Hun Lim
  • Publication number: 20070257185
    Abstract: An image sensor includes a set of at least two pixels each sensing light of a same color coupled to a signal converter. A driver simultaneously turns on a respective switching element for transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a moving image. Alternatively, the driver separately turns on the respective switching element for sequentially transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a still image.
    Type: Application
    Filed: July 5, 2007
    Publication date: November 8, 2007
    Inventor: Tetsuo Asaba
  • Patent number: 7256381
    Abstract: An image sensor includes a set of at least two pixels each sensing light of a same color coupled to a signal converter. A driver simultaneously turns on a respective switching element for transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a moving image. Alternatively, the driver separately turns on the respective switching element for sequentially transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a still image.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: August 14, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Tetsuo Asaba
  • Publication number: 20060284054
    Abstract: A pixel circuit of an image sensor includes a photo-converting unit such as a photo-diode for generating charge from incident light. The pixel circuit also includes a charge storing capacitor for storing the charge generated by the photo-converting unit. The pixel circuit further includes a floating diffusion node that receives the charge from the charge storing unit after being reset. Thus, an image signal VSIG is generated after a reset signal VRES is generated from the pixel circuit.
    Type: Application
    Filed: June 19, 2006
    Publication date: December 21, 2006
    Inventor: Tetsuo Asaba
  • Publication number: 20060278811
    Abstract: A pixel circuit of an image sensor includes a floating diffusion node and a reset transistor. The reset transistor is coupled between the floating diffusion node and a reset control signal node of another pixel circuit of the image sensor. A voltage applied on the reset control signal node of the other pixel circuit is a reset voltage transmitted to the floating diffusion node via the reset transistor.
    Type: Application
    Filed: June 8, 2006
    Publication date: December 14, 2006
    Inventors: Young-Chan Kim, Tetsuo Asaba, Yi-Tae Kim
  • Publication number: 20060138489
    Abstract: A complementary metal-oxide semiconductor (CMOS) active pixel sensor includes a photodiode, a transfer transistor with a coupled gate, a reset transistor and a signal transfer circuit, where the photodiode generates electric charges in response to incident light, the transfer transistor transfers the electric charges integrated in the photodiode to a floating diffusion node, wherein the transfer transistor has a first transfer gate and a second transfer gate, and the first and second transfer gates have a coupled gate structure, the reset transistor resets a potential level of the floating diffusion node by a given voltage level, the signal transfer circuit transfers the potential level of the floating diffusion node to an internal circuit in response to a selection signal, and the CMOS active pixel sensor with the coupled gate may increase a capacity of the photodiode and reduce an image lag by using a voltage coupling effect of the coupled gate.
    Type: Application
    Filed: December 23, 2005
    Publication date: June 29, 2006
    Inventors: Jung-Chak Ahn, Tetsuo Asaba, Young-Chan Kim
  • Publication number: 20060108618
    Abstract: A CMOS image sensor having buried channel MOS transistors is disclosed. The CMOS image sensor includes a photo converting device and a source follower transistor. The photo converting device generates a current signal and changes a voltage of a floating node in response to energy of an incident light. The source follower transistor has a source region doped with a first conductivity-type material, a drain region doped with the first conductivity-type material, a gate region doped with a second conductivity-type material that is complementary to the first conductivity-type material, and a buried channel having the first conductivity-type material. The buried channel is formed between the source region and the drain region and under the gate region.
    Type: Application
    Filed: November 16, 2005
    Publication date: May 25, 2006
    Inventors: Jung-Chak Ahn, Tetsuo Asaba, Yi-Tae Kim, Jung-Yeon Kim, Sung-In Hwang
  • Publication number: 20050280730
    Abstract: Provided are an improved solid-state image-sensing device for averaging sub-sampled analog signals and a method for driving the same. The solid-state image-sensing device receives a video signal from each pixel column and converts the video signal into a digital signal while a switch for averaging is turned off when the solid-state image-sensing device captures a still image. When the solid-state image-sensing device photographs a moving picture, one of two CDS circuits receives a signal corresponding to an average of video signals of columns having the same color pixel and converts the signal into a digital signal using the switch turned on.
    Type: Application
    Filed: June 21, 2005
    Publication date: December 22, 2005
    Inventors: Su-hun Lim, Tetsuo Asaba
  • Publication number: 20050189472
    Abstract: An image sensor includes a set of at least two pixels each sensing light of a same color coupled to a signal converter. A driver simultaneously turns on a respective switching element for transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a moving image. Alternatively, the driver separately turns on the respective switching element for sequentially transferring a respective photocurrent from a respective photodiode within each of such pixels to the signal converter, for capturing a still image.
    Type: Application
    Filed: February 25, 2005
    Publication date: September 1, 2005
    Inventor: Tetsuo Asaba