# US 8,570,420 B2 · Image pickup system, image pickup apparatus and sensitivity control method for correcting sensitivity of an image pickup apparatus using an electron multiplying-charge coupled device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,570,420 B2 - Document ID: US8570420B2 - Status: Granted - Kind: B2 - Application number: 13/064,158 - Filed: 2011-03-09 - Published: 2011-10-27 - Granted: 2013-10-29 - Earliest claimed: 2010-04-21 - Assignees: Hitachi Kokusai Electric Inc. - Applicants: Yutaka Muto; Akira Fukushima - Inventors: Yutaka Muto; Akira Fukushima - Web page: https://patentgrep.com/patent/US8570420B2 ## CPC - H04N 17/002: {for television cameras} - H04N 23/90: Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums - H04N 25/616: involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling - H04N 25/71: Charge-coupled device [CCD] sensors; Charge-transfer registers specially adapted for CCD sensors - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image pickup system includes a plurality of electron multiplication image pickup apparatuses; and a correction coefficient calculating device. The correction coefficient calculating device measures electron multiplication properties of image signals output from the electron multiplication image pickup apparatuses on a regular basis, calculates correction coefficients that are used to adjust the sensitivity of image signals from the electron multiplication apparatus, and sets the calculated correction coefficients in the electron multiplication image pickup apparatuses. ## Claims ### Claim 1 An image pickup system comprising: a plurality of electron multiplication image pickup apparatuses; and a correction coefficient calculating device for measuring electron multiplication properties of image signals output from the electron multiplication image pickup apparatuses, calculating correction coefficients that are used to adjust the sensitivity of image signals from the electron multiplication apparatus, and setting the calculated correction coefficients in the electron multiplication image pickup apparatuses. ### Claim 2 (depends on 1) The image pickup system of claim 1, wherein the correction coefficient calculating device measures electron multiplication properties of image signals output from the electron multiplication image pickup apparatuses on a regular basis, and compares an initially measured electron multiplication property with a most recently measured electron multiplication property for each of the electron multiplication image pickup apparatuses and, if the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property is equal to or greater than a threshold, outputs an alarm signal to the outside. ### Claim 3 (depends on 1) The image pickup system of claim 1, wherein the correction coefficient calculating device measures electron multiplication properties of image signals output from the electron multiplication image pickup apparatuses on a regular basis, and compares an initially measured electron multiplication property with a most recently measured electron multiplication property for each of the electron multiplication image pickup apparatuses and controls each of the electron multiplication image pickup apparatuses such that the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property does not exceed a threshold value. ### Claim 4 An image pickup apparatus for outputting an image signal comprising: an electron multiplying charge coupled device for obtaining an electric signal by performing a photoelectric conversion on an incident light and carrying out an electron multiplication on the electric signal at an electron multiplication factor to generate a multiplied electric signal to be converted into the image signal; a memory unit for storing a correction coefficient acquired from outside the image pickup apparatus based on the image signal output from the image pickup apparatus; a sensitivity setting unit for setting a sensitivity value for the image signal; and a control unit for controlling the electron multiplying-charge coupled device based on a value obtained by multiplying the sensitivity value by the correction coefficient stored in the memory unit. ### Claim 5 (depends on 4) The image pickup apparatus of claim 4, wherein the control unit regularly receives electron multiplication properties measured outside the image pickup apparatus; and compares an initially measured electron multiplication property with a most recently measured electron multiplication property for each of the image pickup apparatuses and, if the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property is equal to or greater than a threshold, outputs an alarm signal to the outside. ### Claim 6 (depends on 4) The image pickup apparatus of claim 4, wherein the control unit regularly receives electron multiplication properties measured outside the image pickup apparatus; and compares an initially measured electron multiplication property with a most recently measured electron multiplication property for each of the image pickup apparatuses and controls each of the image pickup apparatuses such that the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property does not exceed a threshold value. ### Claim 7 A sensitivity control method comprising: measuring electron multiplication properties of an image signal output from an electron multiplication image pickup apparatus; setting a sensitivity value for the image signal; correcting the sensitivity value by multiplying the sensitivity value by a correction coefficient calculated outside the electron multiplication image pickup apparatus based on the measured electron multiplication properties of the image signal; and controlling the electron multiplication image pickup apparatus based on the corrected sensitivity value. ### Claim 8 (depends on 7) The method of claim 7, wherein the measuring of the electron multiplication properties is performed on a regular basis, and the method further comprises: comparing an initially measured electron multiplication property with a most recently measured electron multiplication property; and outputting an alarm signal to the outside, if the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property is equal to or greater than a threshold. ### Claim 9 (depends on 7) The method of claim 7, wherein the measuring of the electron multiplication properties is performed on a regular basis, and the method further comprises: comparing an initially measured electron multiplication property with a most recently measured electron multiplication property; and controlling the electron multiplication image pickup apparatus such that the difference between the initially measured electron multiplication property and the most recently measured electron multiplication property does not exceed a threshold value.