Power efficient image sensing apparatus, method of operating the same and eye/gaze tracking system

An image sensing apparatus comprising:

• a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out;
• a control unit configured to produce a control signal for setting the light sensitive area in the active mode and the standby mode respectively, said control unit configured to produce the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period;
• and
• an output interface configured to deliver output image data from the light sensitive area,
• wherein one data frame represents readout of the image data having been registered by the light sensitive area during a capture time,
• wherein the light sensitive area is configured to feed a sequence of said data frames through the output interface,
• wherein the control unit is configured to produce the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time, and
• wherein after the operation period, the control unit is configured to produce the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area.

An eye/gaze tracking system comprising an image sensing apparatus, said image sensing apparatus comprising:

• a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, wherein the light sensitive area comprises a set of light sensitive elements arranged in a first number of columns and a second number of rows, and wherein the light sensitive area is controllable to read out image data to an output interface, which image data have been registered exclusively by at least one sub-set of the first number of columns and/or the second number of rows;
• a control unit configured to produce a control signal for setting the light sensitive area in the active mode and the standby mode respectively, said control unit configured to produce the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period, wherein the control unit is further configured to produce the control signal so that said at least one subset of image data is fed to the output interface when the light sensitive area operates in the active mode;
• and
• an output interface configured to deliver output image data from the light sensitive area,
• wherein one data frame represents readout of the image data having been registered by the light sensitive area during a capture time,
• wherein the light sensitive area is configured to feed a sequence of said data frames through the output interface,
• wherein the control unit is configured to produce the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time,
• wherein prior to the operation period, the control unit is configured to produce the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area,
• wherein the image sensing apparatus being arranged to capture image data of a subject whose eye and or gaze is tracked, and
• wherein the control unit is configured to produce the control signal so that said at least one subset of image data represents the image of at least one eye of the subject.

A method of controlling an image sensing apparatus having a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, and said image sensing apparatus further having an output interface configured to deliver output image data from the light sensitive area;

• the method comprising:
• producing a control signal for setting the light sensitive area in the active mode and the standby mode respectively;
• producing the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period;
• reading out one data frame representing image data having been registered by the light sensitive area during a capture time;
• feeding out a sequence of said data frames from the light sensitive area through the output interface;
• and
• producing the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time,
• wherein, prior to the operation period, said producing comprises producing the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area.

A computer program product stored on a non-transitory computer readable medium, comprising software instructions for operation by a computer controller for controlling an image sensing apparatus having a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, and said image sensing apparatus further having an output interface configured to deliver output image data from the light sensitive area, said instructions comprising:

• first instructions for producing a control signal for setting the light sensitive area in the active mode and the standby mode respectively;
• second instructions for producing the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period;
• third instructions for reading out one data frame representing image data having been registered by the light sensitive area during a capture time;
• and
• fourth instructions for feeding out a sequence of said data frames from the light sensitive area through the output interface,
• wherein said second instructions includes instructions for producing the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time, and
• wherein said second instructions comprising, prior to the operation period, instructions for producing the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area.

An eye/gaze tracking system comprising an image sensing apparatus, said image sensing apparatus comprising:

• a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, wherein the light sensitive area comprises a set of light sensitive elements arranged in a first number of columns and a second number of rows, and wherein the light sensitive area is controllable to read out image data to an output interface, which image data have been registered exclusively by at least one sub-set of the first number of columns and/or the second number of rows;
• a control unit configured to produce a control signal for setting the light sensitive area in the active mode and the standby mode respectively, said control unit configured to produce the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period, wherein the control unit is further configured to produce the control signal so that said at least one subset of image data is fed to the output interface when the light sensitive area operates in the active mode;
• and
• an output interface configured to deliver output image data from the light sensitive area,
• wherein one data frame represents readout of the image data having been registered by the light sensitive area during a capture time,
• wherein the light sensitive area is configured to feed a sequence of said data frames through the output interface,
• wherein the control unit is configured to produce the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time,
• wherein after the operation period, the control unit is configured to produce the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area,
• wherein the image sensing apparatus being arranged to capture image data of a subject whose eye and or gaze is tracked, and
• wherein the control unit is configured to produce the control signal so that said at least one subset of image data represents the image of at least one eye of the subject.

A method of controlling an image sensing apparatus having a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, and said image sensing apparatus further having an output interface configured to deliver output image data from the light sensitive area;

• the method comprising:
• producing a control signal for setting the light sensitive area in the active mode and the standby mode respectively;
• producing the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period;
• reading out one data frame representing image data having been registered by the light sensitive area during a capture time;
• feeding out a sequence of said data frames from the light sensitive area through the output interface;
• and
• producing the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time,
• wherein, after the operation period, said producing comprises producing the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area.

A computer program product stored on a non-transitory computer readable medium, comprising software instructions for operation by a computer controller for controlling an image sensing apparatus having a light sensitive area configured to register image data in response to an incoming amount of light, the light sensitive area being operable in an active mode wherein image data can be read out there from and a standby mode wherein image data cannot be read out, and said image sensing apparatus further having an output interface configured to deliver output image data from the light sensitive area, said instructions comprising:

• first instructions for producing a control signal for setting the light sensitive area in the active mode and the standby mode respectively;
• second instructions for producing the control signal such that the light sensitive area transitions from operation in the active mode to the standby mode and back to the active mode in a cyclic manner during an operation period;
• third instructions for reading out one data frame representing image data having been registered by the light sensitive area during a capture time;
• and
• fourth instructions for feeding out a sequence of said data frames from the light sensitive area through the output interface,
• wherein said second instructions includes instructions for producing the control signal so that the operation period extends over at least one capture time and at least two periods during which the light sensitive area operates in the standby mode, the light sensitive area operating in the active mode during said at least one capture time, and
• wherein said second instructions comprising, after the operation period, instructions for producing the control signal so that the light sensitive area operates in the active mode during an unbroken period of time exceeding a typical capture time associated with a full readout of image data from the light sensitive area.