# US 2021/0344857 A1 · Image sensing device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344857 A1 - Document ID: US20210344857A1 - Status: Published application - Kind: A1 - Application number: 17/039,008 - Filed: 2020-09-30 - Published: 2021-11-04 - Earliest claimed: 2020-05-04 - Assignees: SK hynix Inc. - Applicants: SK hynix Inc. - Inventors: Won Seok HWANG - Web page: https://patentgrep.com/patent/US20210344857A1 ## CPC - H04N 25/75: Circuitry for providing, modifying or processing image signals from the pixel array - H04N 25/76: Addressed sensors, e.g. MOS or CMOS sensors - H04N 25/709: Circuitry for control of the power supply - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H03K 5/2481: {with at least one differential stage} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract An image sensing device includes first and anterior comparators and first and second posterior comparators. The first anterior comparator generates a first anterior comparison signal based on a first pixel signal and a ramp signal. The first posterior comparator performs a first comparison that compares the first anterior comparison signal with a first reference signal under a first comparison precondition and generates a first posterior comparison signal corresponding to a result of the first comparison. The second anterior comparator generates a second anterior comparison signal based on a second pixel signal and the ramp signal. The second posterior comparator performs a second comparison that compares the second anterior comparison signal with a second reference signal under a second comparison precondition different from the first comparison precondition. The second posterior comparator generates a second posterior comparison signal corresponding to a result of the second comparison. ## Claims ### Claim 1 An image sensing device comprising: a first anterior comparator suitable for generating a first anterior comparison signal based on a first pixel signal and a ramp signal; a first posterior comparator suitable for performing a first comparison that compares the first anterior comparison signal with a first reference signal under a first comparison precondition and generating a first posterior comparison signal corresponding to a result of the first comparison; a second anterior comparator suitable for generating a second anterior comparison signal based on a second pixel signal and the ramp signal; and a second posterior comparator suitable for performing a second comparison that compares the second anterior comparison signal with a second reference signal under a second comparison precondition different from the first comparison precondition, and suitable for generating a second posterior comparison signal corresponding to a result of the second comparison. ### Claim 2 (depends on 1) The image sensing device of claim 1, wherein the first comparison precondition includes a condition for initializing an input terminal, to which the first anterior comparison signal is input, to a first voltage level, and the second comparison precondition includes a condition for initializing an input terminal, to which the second anterior comparison signal is input, to a second voltage level different from the first voltage level. ### Claim 3 (depends on 2) The image sensing device of claim 2, wherein the first voltage level corresponds to a voltage level of the first reference signal adjusted during an initialization time, and the second voltage level corresponds to a voltage level of the second reference signal adjusted during the initialization time. ### Claim 4 (depends on 1) The image sensing device of claim 1, wherein the first comparison precondition includes a condition for adjusting a voltage level of the first reference signal to a first voltage level, and the second comparison precondition includes a condition for adjusting a voltage level of the second reference signal to a second voltage level different from the first voltage level. ### Claim 5 (depends on 1) The image sensing device of claim 1, wherein the first and second anterior comparators operate under a same comparison precondition. ### Claim 6 (depends on 1) The image sensing device of claim 1, further comprising: a first sampling circuit coupled to the first posterior comparator and suitable for sampling the first reference signal; and a second sampling circuit coupled to the second posterior comparator and suitable for sampling the second reference signal. ### Claim 7 (depends on 1) The image sensing device of claim 1, wherein the first posterior comparator generates and adjusts the first reference signal through self-generation based on a first control code signal. ### Claim 8 (depends on 1) The image sensing device of claim 1, wherein the first posterior comparator includes: an input circuit suitable for receiving the first pixel signal and the first reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal and suitable for generating a first current corresponding to a voltage level of the first reference signal; and a second current source coupled between the input circuit and the second voltage terminal and suitable for generating a first adjusting current for adjusting the voltage level of the first reference signal based on a first control code signal. ### Claim 9 (depends on 1) The image sensing device of claim 1, wherein the second posterior comparator generates and adjusts the second reference signal through self-generation based on a second control code signal. ### Claim 10 (depends on 1) The image sensing device of claim 1, wherein the second posterior comparator includes: an input circuit suitable for receiving the second pixel signal and the second reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal, and suitable for generating a second current corresponding to a voltage level of the second reference signal; and a second current source coupled between the input circuit and the second voltage terminal, and suitable for generating a second adjusting current for adjusting the voltage level of the second reference signal based on a second control code signal. ### Claim 11 An image sensing device, comprising: a first anterior comparator configured to be initialized during an initialization time and suitable for generating a first anterior comparison signal based on a first pixel signal and a ramp signal during a row time; a first posterior comparator suitable for initializing a first input terminal to a first voltage level and a first sub-input terminal to a default voltage level during the initialization time and generating a first posterior comparison signal based on the first anterior comparison signal input through the first input terminal and a first reference signal input through the first sub-input terminal during the row time; a second anterior comparator configured to be initialized during the initialization time and suitable for generating a second anterior comparison signal based on a second pixel signal and the ramp signal during the row time; and a second posterior comparator suitable for initializing a second input terminal to a second voltage level different from the first voltage level and a second sub-input terminal to the default voltage level during the initialization time, and generating a second posterior comparison signal based on the second anterior comparison signal input through the second input terminal and a second reference signal input through the second sub-input terminal during the row time. ### Claim 12 (depends on 11) The image sensing device of claim 11, further comprising: a first sampling circuit coupled to the first posterior comparator and suitable for sampling the first reference signal; and a second sampling circuit coupled to the second posterior comparator, and suitable for sampling the second reference signal. ### Claim 13 (depends on 11) The image sensing device of claim 11, wherein the first posterior comparator generates and adjusts the first reference signal through self-generation based on a first control code signal, and the second posterior comparator generates and adjusts the second reference signal through self-generation based on a second control code signal. ### Claim 14 (depends on 11) The image sensing device of claim 11, wherein the first posterior comparator includes: an input circuit suitable for receiving the first pixel signal and the first reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal, and suitable for generating a first current corresponding to a voltage level of the first reference signal; and a second current source coupled between the input circuit and the second voltage terminal, and suitable for generating a first adjusting current for adjusting the voltage level of the first reference signal based on a first control code signal. ### Claim 15 (depends on 11) The image sensing device of claim 11, wherein the second posterior comparator includes: an input circuit suitable for receiving the second pixel signal and the second reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal, and suitable for generating a second current corresponding to a voltage level of the second reference signal; and a second current source coupled between the input circuit and the second voltage terminal, and suitable for generating a second adjusting current for adjusting the voltage level of the second reference signal based on a second control code signal. ### Claim 16 An image sensing device, comprising: a first anterior comparator to be initialized during an initialization time and suitable for generating a first anterior comparison signal based on a first pixel signal and a ramp signal during a row time; a first posterior comparator suitable for adjusting a voltage level of a first reference signal to a first voltage level during the initialization time, and generating a first posterior comparison signal based on the first anterior comparison signal and the first reference signal during the row time; a second anterior comparator to be initialized during the initialization time, and suitable for generating a second anterior comparison signal based on a second pixel signal and the ramp signal during the row time; and a second posterior comparator suitable for adjusting a voltage level of a second reference signal to a second voltage level different to the first voltage level during the initialization time, and generating a second posterior comparison signal based on the second anterior comparison signal and the second reference signal during the row time. ### Claim 17 (depends on 16) The image sensing device of claim 16, further comprising: a first sampling circuit coupled to the first posterior comparator and suitable for sampling the first reference signal; and a second sampling circuit coupled to the second posterior comparator, and suitable for sampling the second reference signal. ### Claim 18 (depends on 16) The image sensing device of claim 16, wherein the first posterior comparator generates and adjusts the first reference signal through self-generation based on a first control code signal, and the second posterior comparator generates and adjusts the second reference signal through self-generation based on a second control code signal. ### Claim 19 (depends on 16) The image sensing device of claim 16, wherein the first posterior comparator includes: an input circuit suitable for receiving the first pixel signal and the first reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal, and suitable for generating a first current corresponding to a voltage level of the first reference signal; and a second current source coupled between the input circuit and the second voltage terminal, and suitable for generating a first adjusting current for adjusting the voltage level of the first reference signal based on a first control code signal. ### Claim 20 (depends on 16) The image sensing device of claim 16, wherein the second posterior comparator includes: an input circuit suitable for receiving the second pixel signal and the second reference signal; a loading circuit coupled between the input circuit and a first voltage terminal; a first current source coupled between the input circuit and a second voltage terminal, and suitable for generating a second current corresponding to a voltage level of the second reference signal; and a second current source coupled between the input circuit and the second voltage terminal and suitable for generating a second adjusting current for adjusting the voltage level of the second reference signal based on a second control code signal.