Method for operating a camera and a projector in a synchronized manner
A method for synchronizing a camera that has an image sensor with a projector that can generate a synchronization signal which corresponds to the projector frame rate. The projector is operated with a frame rate (F 2 ), and the camera is operated with a frame rate (F 1 ). A blanking interval is formed between individual images, and the synchronization signal of the projector is provided for controlling the camera. In order to match a phase (P 1 ) of the frame rate (F 1 ) of the camera to a phase (P 2 ) of the frame rate (F 2 ) of the projector and/or in order to match the frame rate (F 1 ) of the camera to the frame rate (F 2 ) of the projector, one or more blanking intervals between the individual images of the camera are varied dependent on the synchronization signal of the projector. For this purpose, a control circuit carries out a comparison between the phase (P 1 ) of the frame rate (F 1 ) of the camera and the phase (P 2 ) of the frame rate (F 2 ) of the projector and/or between the frame rate (F 1 ) of the camera and the frame rate (F 2 ) of the projector, wherein the trigger input of the image sensor is not activated for the matching process.
1. A method for synchronizing a camera that comprises an image sensor with a projector that can generate a synchronization signal which corresponds to a projector frame rate, comprising the steps of:
a) operating the projector that projects a pattern at a projection frame rate F 2 ,
b) operating the camera and capturing the projected pattern at a capture frame rate F 1 , wherein a blanking interval is formed/defined between individual frames, before capturing these frames,
c) providing the synchronization signal of the projector for controlling the camera, before capturing these frames,
d) varying one or several blanking intervals between the individual frames of the camera depending on the synchronization signal from the projector to match a phase P 1 of the capture frame rate F 1 of the camera and the projection frame rate F 2 of the projector, in a way that a starting point of an exposure of the camera or the image sensor occurs simultaneously with a starting point of a projection of the projector, for which purpose a control circuit compares the phase P 1 of the capture frame rate F 1 of the camera and the phase P 2 of the projection frame rate F 2 of the projector and/or of the capture frame rate F 1 of the camera and the projection frame rate F 2 of the projector, wherein a trigger input of an image sensor is not actuated for adjusting the blanking interval.
2. The method according to claim 1 , wherein the synchronization signal comprises an almost constant frequency.
3. The method according to claim 2 , wherein the blanking intervals are in the case in which the phase P 1 of the capture frame rate F 1 of the camera is shifted toward early relative to phase P 2 of the projection frame rate F 2 of the projector and that the blanking intervals are decreased in the case in which the phase P 1 of the capture frame rate F 1 of the camera is shifted toward late relative to the phase P 2 of the projection frame rate F 2 of the projector.
4. The method according to claim 3 , wherein the blanking intervals are increased in the case in which the capture frame rate F 1 of the camera is greater than the projection frame rate F 2 of the projector, and/or the blanking intervals are decreased in the case in which the capture frame rate F 1 of the camera is smaller than the projection frame rate F 2 of the projector.
5. The method according to claim 4 , wherein a camera is used whose capture frame rate F 1 is greater than the projection frame rate F 2 of the projector before the synchronization takes place.
6. The method according to claim 5 , wherein the synchronization signal is captured by the projector via an electronic component, a circuit, a closed-loop control circuit, or an IC and the length of the blanking intervals is controlled and/or regulated via an electronic component, a circuit, a closed-loop control circuit, or an IC.
7. The method according to claim 6 , wherein another camera or unit issuing a synchronization signal is used in addition to the projector and that the capture frame rate F 1 and/or phase P 1 of the camera is adjusted to its projection frame rate F 2 .
8. The method according to claim 1 , wherein the blanking intervals are in the case in which the phase P 1 of the capture frame rate F 1 of the camera is shifted toward early relative to phase P 2 of the projection frame rate F 2 of the projector and that the blanking intervals are decreased in the case in which the phase P 1 of the capture frame rate F 1 of the camera is shifted toward late relative to the phase P 2 of the projection frame rate F 2 of the projector.
9. The method according to claim 1 , wherein the blanking intervals are increased in the case in which the capture frame rate F 1 of the camera is greater than the projection frame rate F 2 of the projector, and/or the blanking intervals are decreased in the case in which the capture frame rate F 1 of the camera is smaller than the projection frame rate F 2 of the projector.
10. The method according to claim 1 , wherein a camera is used whose capture frame rate F 1 is greater than the projection frame rate F 2 of the projector before the synchronization takes place.
11. The method according to claim 1 , wherein the synchronization signal is captured by the projector via an electronic component, a circuit, a closed-bop control circuit, or an IC and the length of the blanking intervals is controlled and/or regulated via an electronic component, a circuit, a closed-loop control circuit, or an IC.
12. The method according to claim 1 , wherein another camera or unit issuing a synchronization signal is used in addition to the projector and that the capture frame rate F 1 and/or phase P 1 of the camera is adjusted to its projection frame rate F 2 .
13. A system for generating 3D images with a camera and a projector or another camera, which is operated using the method according to claim 1 .