Patents by Inventor Do-chan Choi

Do-chan Choi 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: 20240080320
    Abstract: A server according to an embodiment includes a processor configured to receive a friend add request for a target account from a user terminal accessed with a user account; based on one of the user account and the target account being a protected account, transmit an approval request for the friend add request to a protector account connected to the protected account; and based on receiving a reply to the approval request from the protector terminal, add the target account to a friend list of the user account.
    Type: Application
    Filed: April 27, 2023
    Publication date: March 7, 2024
    Inventors: You Jin KIM, Jung Woo CHOI, Jenog Ryeol CHOI, Joong Seon KIM, Hong Chan YUN, Ju Ho CHUNG, Do Hyun YOUN, Hyung Min KIM, Hyun Ok CHOI, Chun Ho KIM, Soo Beom KIM, Min Jeong KIM, Chang Oh HEO, Eun Soo HEO
  • Publication number: 20070038831
    Abstract: A memory module includes a plurality of semiconductor memory devices, a plurality of module tabs and a memory buffer. The plurality of the semiconductor memory devices stores first data, wherein at least one of the plurality of the semiconductor memory devices has a lower latency. The plurality of the module tabs is used to transfer a signal and data to/from an external device. The memory buffer buffers the first data output from the semiconductor memory devices to the module tabs and buffers second data and a signal provided from an external device through the module tabs to the semiconductor memory devices. Therefore, a latency of a memory module may be reduced.
    Type: Application
    Filed: May 2, 2006
    Publication date: February 15, 2007
    Inventors: Hong-Kyun Kim, Do-Chan Choi
  • Patent number: 6012122
    Abstract: A plurality of memory types are distinguished from one another in memory systems containing a plurality of memory types by applying an input signal to the memory system containing the plurality of memory types and detecting differing outputs from the plurality of memory types during a predetermined time period after the input signal is applied. Extended data output (EDO), dynamic random access memories (DRAM) are thereby distinguished from fast page mode (F/P) DRAM. Similarly, nonvolatile memory such as DRAM interface flash memory (DIFM) are distinguished from conventional DRAMs.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: January 4, 2000
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-Chan Choi, Tae-Sung Jung, Oh-Seung Kwon
  • Patent number: 5809553
    Abstract: Nonvolatile memory devices and methods include an array of nonvolatile memory cells which are arranged in a plurality of rows and a plurality of columns. A plurality of word lines are also included, a respective one of which is connected to the nonvolatile memory cells in a respective one of a plurality of columns. A plurality of lockable cells are also included. A respective one of the lockable cells is connected to a respective one of the plurality of word lines. Each of the lockable cells stores therein a first or a second binary value. The first binary value indicates that nonvolatile memory cells which are connected to the corresponding column of word lines cannot be erased or reprogrammed. The second binary value indicates that nonvolatile memory cells which are connected to the corresponding column of words lines can be erased or programmed.
    Type: Grant
    Filed: December 20, 1996
    Date of Patent: September 15, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-Chan Choi, Jong-Chang Son
  • Patent number: 5737258
    Abstract: An electrically erasable and programmable nonvolatile memory device (EEPROM) such as a flash memory, is pin compatible with a dynamic random access memory device (DRAM), such that flash memory may be connected to a DRAM bus. Preferably, the flash memory is read and write timing-compatible with the DRAM read and write signals and is also preferably block read and block write timing compatible with DRAM block read and block write signals. The flash memory accepts signals to perform sleep and erase functions from signal lines of a DRAM bus which are not used by a DRAM. In order to perform a block erase, which is a characteristic of flash memory, the device preferably accepts an instruction to perform a block erase from signal lines of a DRAM bus which are not used by a DRAM and a block address for the block erase from the most significant bit address lines of the DRAM bus.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: April 7, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-Chan Choi, Woung-Moo Lee, Tae-Sung Jung, Syed Ali, Ejaz Haq
  • Patent number: 5732018
    Abstract: Nonvolatile integrated circuit memory devices, such as EEPROMs, use unselected shared latching sense amplifiers to latch data from memory cells which are to be reprogrammed after a page erase, and to resupply the latch data to the memory cells which are to be programmed after erase, to thereby internally reprogram the latched data into erased memory cells after page programming. Transferring circuits and methods are provided for transferring data between shared latching sense amplifiers to permit internal reprogramming. High speed and simplified reprogramming of EEPROMs is thereby provided.
    Type: Grant
    Filed: October 29, 1996
    Date of Patent: March 24, 1998
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-Chan Choi, Tae-Sung Jung, Woung-Moo Lee, Ejaz Haq, Syed Ali
  • Patent number: 5717354
    Abstract: An input protection circuit for a semiconductor memory device senses when the level of an external input signal drops below a reference voltage corresponding to a predetermined logic level, thereby enabling instant correction. The input protection circuit is interposed between an external power voltage terminal and an input terminal of the input buffer, and the external power voltage is transferred to the input terminal of the input buffer when the level of the external input signal applied to the input terminal drops below the predetermined logic level. The circuit includes an internal reference voltage generator which supplies a voltage having a level corresponding to the predetermined logic level and designed to compensate for a known device offset so that the external input signal applied to the input terminal can be instantly corrected.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: February 10, 1998
    Assignee: Samsung Electronics Co., LTD.
    Inventors: Myung-Jae Kim, Do-Chan Choi
  • Patent number: 5367489
    Abstract: A high density semiconductor device is provided with an improved voltage pumping (bootstrapping) circuit. The voltage pumping circuit generates at an initial power-up state a first output voltage which is substantially identical to the memory device source supply voltage. The pumping circuit then pumps the first output voltage up to a second output voltage which is higher than the first output voltage. The pumping operation is achieved prior to or upon the semiconductor memory device being enabled in response to a series of pulses output from an oscillator.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: November 22, 1994
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chan-Sok Park, Young-Gwon Choi, Dong-Jae Lee, Do-Chan Choi, Dong-Soo Jun, Yong-Sik Seok
  • Patent number: 5321306
    Abstract: A method for manufacturing a semiconductor device includes forming contact holes in insulating layers to expose an impurity doped region of a semiconductor substrate. An epitaxial layer is then grown in the contact hole. A polycrystalline silicon layer is formed over the top to provide the lower electrode of a capacitor. Accordingly, the polycrystalline layer is separated from the impurity doped region thereby preventing current leakage.
    Type: Grant
    Filed: February 7, 1992
    Date of Patent: June 14, 1994
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-chan Choi, Kyung-tae Kim
  • Patent number: 5305282
    Abstract: An address input buffer of a semiconductor memory device comprises an address input terminal, a column address switch, a row address switch, a column address latch connected to the column address switch, a row address latch connected to the row address switch, and an input buffer connected to the address input terminal, and the common node of the column address switch and the row address switch and controlled by an input buffer control signal. Thus, layout area can be reduced by buffering the row and column address input signals with one input buffer without separating the column and row address buffers.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: April 19, 1994
    Assignee: Samsung Electric Co., Ltd.
    Inventor: Do-chan Choi
  • Patent number: 5291052
    Abstract: A MOS semiconductor device and the methods for constructing the device. The MOS device provided with first and second MOS transistors are formed on two identical wafer sections. The impurity region of the first transistor and a first group of gate side wall spacers are aligned to the gate of the first transistor. The impurity region of the second transistor and a second group of gate side wall spacers are aligned to the gate of the second MOS transistor. The second group of gate side wall spacers have a thickness different from that of the first group of gate side wall spacers.
    Type: Grant
    Filed: August 30, 1991
    Date of Patent: March 1, 1994
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyeong-tae Kim, Do-chan Choi
  • Patent number: 5175121
    Abstract: A method for manufacturing a semiconductor device includes forming contact holes in insulating layers to expose an impurity doped region of a semiconductor substrate. An epitaxial layer is then grown in the contact hole. A polycrystalline silicon layer is formed over the top to provide the lower electrode of a capacitor. Accordingly, the polycrystalline layer is separated from the impurity doped region thereby preventing current leakage.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: December 29, 1992
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-chan Choi, Kyung-tae Kim
  • Patent number: 5045494
    Abstract: A method for manufacturing a semiconductor device includes forming contact holes in insulating layers to expose an impurity doped region of a semiconductor substrate. An epitaxial layer is then grown in the contact hole. A polycrystalline silicon layer is formed over the top to provide the lower electrode of a capacitor. Accordingly, the polycrystalline layer is separated from the impurity doped region thereby preventing current leakage.
    Type: Grant
    Filed: March 15, 1990
    Date of Patent: September 3, 1991
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Do-chan Choi, Kyung-tae Kim