Time-of-flight camera with motion detection
A method for operating a time-of-flight camera including a time-of-flight sensor comprising an array of time-of-flight pixels with at least two integration nodes, wherein in a 3D mode the time-of-flight sensor and an illumination means are operated by means of a modulation signal and on the basis of the charges accumulated at the integration nodes distance values are determined, characterized in that in a power saving mode the time-of-flight sensor is operated with a control signal for motion detection, the frequency of which is lower than a lowest frequency of the modulation signal for a distance determination in the 3D mode, wherein an object motion is determined based on a differential value at the integration nodes is provided.
1. A method for operating a time-of-flight camera including a time-of-flight sensor comprising an array of time-of-flight pixels with at least two integration nodes, wherein in a 3D mode the time-of-flight sensor and an illumination means are operated by means of a modulation signal and on the basis of the charges accumulated at the integration nodes distance values are determined;
wherein in a power saving mode the time-of-flight sensor is operated for motion detection with a control signal, wherein each of the at least two integration nodes are triggered by means of the control signal and wherein the frequency of the control signal is lower than a lowest frequency of the modulation signal for a distance determination in the 3D mode,
wherein an object motion is determined based on a differential value at the at least two integration nodes.
2. The method according to claim 1 , wherein in the power saving mode, the differential value is compared with a threshold value and, if the threshold value is exceeded, this is identified as an object motion.
3. The method according to claim 1 , wherein the power saving mode is switched to the 3D mode as soon as an object motion is identified in a power saving mode.
4. The method according to claim 1 , wherein in the power saving mode the detection of the differential values is performed with a lower acquisition rate compared to the 3D mode.
5. The method according to claim 1 , wherein in the power saving mode the frequency of the control signal is less than 10% of the lowest frequency of the modulation signal used for the distance determination in the 3D mode.
6. A time-of-flight camera comprising a time-of-flight sensor including an array of time-of-flight pixels comprising at least two integration nodes, wherein the time-of-flight camera is configured such that in a 3D mode a modulator provides a modulation signal based on which an illumination means emits modulated light and the time-of-flight sensor demodulates detected light for determining a distance value;
wherein the time-of-flight camera is configured to carry out a method according to claim 1 .
7. The method according to claim 1 , wherein each of the at least two integration nodes is triggered only once within an acquisition period.