# US 2018/0324370 A1 · Method, apparatus, and system providing an imager with pixels having extended dynamic range > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0324370 A1 - Document ID: US20180324370A1 - Status: Published application - Kind: A1 - Application number: 16/025,842 - Filed: 2018-07-02 - Published: 2018-11-08 - Earliest claimed: 2006-08-25 - Assignees: Micron Technology, Inc. - Applicants: Micron Technology, Inc. - Inventors: Nikolai E. Bock - Web page: https://patentgrep.com/patent/US20180324370A1 ## CPC - H04N 25/59: by controlling the amount of charge storable in the pixel, e.g. modification of the charge conversion ratio of the floating node capacitance - H04N 23/76: by influencing the image signals - H04N 25/53: Control of the integration time - H04N 25/532: by controlling global shutters in CMOS SSIS - H04N 25/57: Control of the dynamic range - H04N 25/583: with different integration times - H04N 25/589: with different integration times, e.g. short and long exposures - H04N 25/75: Circuitry for providing, modifying or processing image signals from the pixel array - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H10F 39/813: {Electronic components shared by multiple pixels, e.g. one amplifier shared by two pixels} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract The dynamic range of a pixel is increased by using selective photosensor resets during a frame time of image capture at a timing depending on the light intensity that the pixel will be exposed to during the frame time. Pixels that will be exposed to high light intensity are reset later in the frame than pixels that will be exposed to lower light intensity. ## Claims ### Claim 1 A method of operating an imager, the method comprising: determining a value of light intensity to which a pixel will be exposed during a frame time; resetting charge accumulated in a photosensor of the pixel during the frame time at a timing determined in response to the determined value of light intensity; transferring the charge on the photosensor at the end of the frame time to a storage region; and generating a pixel image signal in response to the charge transferred to the storage region. ### Claim 2 (depends on 1) The method of claim 1, wherein the charge is reset earlier in the frame time when the determined value of light intensity is lower, and wherein the charge is reset later in the frame time when the determined value of light intensity is higher. ### Claim 3 (depends on 1) The method of claim 1, wherein the charge is reset at a predetermined time of a plurality of predetermined times during the frame time. ### Claim 4 (depends on 3) The method of claim 3, wherein the predetermined time corresponds to a predetermined range of potential values of light intensity of a plurality of predetermined ranges of potential values of light intensity, and wherein the determined value of light intensity falls within the predetermined range of potential values of light intensity. ### Claim 5 (depends on 3) The method of claim 3, wherein the predetermined time is one of four predetermined times during the frame time, wherein the predetermined time corresponds to a predetermined range of potential values of light intensity of four predetermined ranges of potential values of light intensity, and wherein the determined value of light intensity falls within the predetermined range of potential values of light intensity. ### Claim 6 (depends on 1) The method of claim 1, further comprising adjusting a gain of the pixel image signal using a value that correlates to a range of potential values of light intensity into which the determined value of light intensity falls. ### Claim 7 (depends on 1) The method of claim 1, further comprising assigning a brightness value to the pixel, wherein the brightness value corresponds to a range of potential values of light intensity of a plurality of ranges of potential values of light intensity, and wherein the determined value of light intensity falls within the range of potential values of light intensity. ### Claim 8 (depends on 7) The method of claim 7, wherein the charge is reset at a timing associated with the brightness value assigned to the pixel. ### Claim 9 (depends on 7) The method of claim 7, wherein the range of potential values of light intensity is one of four ranges of potential values of light intensity. ### Claim 10 (depends on 7) The method of claim 7, further comprising storing the brightness value assigned to the pixel to memory. ### Claim 11 (depends on 10) The method of claim 10, wherein the brightness value is assigned to a zone of contiguous pixels that include the pixel, and wherein the brightness value is stored to memory by storing the brightness value and a location of the zone. ### Claim 12 (depends on 11) The method of claim 11, wherein the location of the zone is stored to memory by storing (i) a location of a pixel located to a farthest point left in each row of the zone, (ii) a location of a pixel located to a farthest point right in each row of the zone, (iii) a location of an uppermost row of the zone, and (iv) a location of a lowermost row of the zone. ### Claim 13 (depends on 11) The method of claim 11, wherein the location of the zone is stored to memory by (i) approximating a shape of the zone using a simple shape and (ii) storing a location of the simple shape to memory. ### Claim 14 (depends on 13) The method of claim 13, wherein the simple shape is a rectangle, and wherein the location of the rectangle is stored to memory by storing (i) a location of a corner of the rectangle, (ii) a length of the rectangle, and (iii) a width of the rectangle. ### Claim 15 (depends on 13) The method of claim 13, wherein the simple shape is a circle, and wherein the location of the circle is stored to memory by storing (i) a location of a center of the circle and (ii) a radius of the circle. ### Claim 16 A method of operating an imager, the method comprising: acquiring information regarding an intensity of light to which a pixel will be exposed during a subsequent image capture period; correlating the information with a range of light intensity values within a plurality of ranges of light intensity values; and using the range of light intensity values to set a timing to reset a charge accumulated in a photosensor of the pixel during the image capture period. ### Claim 17 (depends on 16) The method of claim 16, wherein the charge is reset earlier in the image capture period when the intensity of light is lower, and wherein the charge is reset later in the image capture period when the intensity of light is higher. ### Claim 18 (depends on 16) The method of claim 16, further comprising: transferring the charge to a storage region at the end of the image capture period; and generating a pixel image signal from the charge transferred to the storage region. ### Claim 19 (depends on 18) The method of claim 18, further comprising adjusting a gain of the pixel image signal using a value that correlates to the information. ### Claim 20 A method of storing values assigned to pixels in a pixel array to memory, the method comprising storing a location of and a value assigned to a zone of a plurality of contiguous pixels in the pixel array. ### Claim 21 (depends on 20) The method of claim 20, wherein the location of the zone is stored to memory by storing (i) a location of a pixel located to a farthest point left in each row in the zone, (ii) a location of a pixel located to a farthest point right in each row in the zone, (iii) a location of an uppermost row in the zone, and (iv) a location of a lowermost row in the zone. ### Claim 22 (depends on 20) The method of claim 20, wherein the location of the zone is stored to memory by (i) approximating a shape of the zone using a simple shape and (ii) storing a location of the simple shape to memory. ### Claim 23 (depends on 22) The method of claim 22, wherein the simple shape is a rectangle, and wherein the location of the rectangle is stored to memory by storing (i) a location of a corner of the rectangle, (ii) a length of the rectangle, and (iii) a width of the rectangle. ### Claim 24 (depends on 22) The method of claim 22, wherein the simple shape is a circle, and wherein the location of the circle is stored to memory by storing (i) a location of a center of the circle and (ii) a radius of the circle. ### Claim 25 A method of operating an imager, the method comprising: accumulating charge in a first pixel in a pixel array for a first time period during a frame time; accumulating charge in a second pixel in the pixel array for a second time period during the frame time, wherein the first time period is longer in duration than the second time period, wherein a duration of the first time period is determined in response to a first brightness to which the first pixel will be exposed during the frame time, and wherein a duration of the second time period is determined in response to a second brightness to which the second pixel will be exposed during the frame time. ### Claim 26 (depends on 25) The method of claim 25, wherein the charge accumulated in the second pixel is reset during the frame time prior to the second time period. ### Claim 27 (depends on 26) The method of claim 26, wherein the charge accumulated in the second pixel is reset (i) earlier in the frame time when the second brightness is lower and (ii) later in the frame time when the second brightness is higher. ### Claim 28 (depends on 26) The method of claim 26, wherein the charge accumulated in the second pixel is reset at a predetermined time during the frame time in a plurality of predetermined times during the frame time. ### Claim 29 (depends on 28) The method of claim 28, wherein the predetermined time corresponds to a predetermined range of brightness in a plurality of predetermined ranges of brightness, and wherein the second brightness falls within the predetermined range of brightness. ### Claim 30 A method of operating an imager, the method comprising: establishing a time frame during which a pixel may capture data, and capturing data for only a portion of the frame time in response to illumination to which the pixel is exposed during the frame period. ### Claim 31 (depends on 30) The method of claim 30, further comprising deleting data accumulated outside the portion of the frame time by resetting a charge accumulated by the pixel. ### Claim 32 (depends on 30) The method of claim 30, wherein a length of the portion of the frame time is (i) longer when the illumination is lower and (ii) shorter when the illumination is higher. ### Claim 33 (depends on 32) The method of claim 32, wherein the length of the portion of the frame time is a predetermined length of a plurality of predetermined lengths. ### Claim 34 (depends on 33) The method of claim 33, wherein the predetermined length corresponds to a predetermined range of illumination of a plurality of predetermined ranges of illumination, and wherein the illumination to which the pixel is exposed falls within the predetermined range of illumination.