Apparatus and method for compensating hand blur
An apparatus and method for compensating hand blur are disclosed. The method according to an exemplary embodiment of the present invention comprises receiving an angular velocity by tilt of the camera module, determining a first driving signal for driving the second actuator using the angular velocity, calculating a ratio of effective focal length relative to a lens moving distance using the driving of the first actuator, and determining a second driving signal amplifying the first driving signal, using the ratio of effective focal length relative to the lens moving distance.
1. An apparatus for compensating an image blur caused by hand blur of a camera module including a first actuator for AF (Auto Focus)/zoom, and a second actuator for OIS (Optical Image Stabilizer), the apparatus comprising:
a controller configured to determine a first driving signal for driving the second actuator using angular velocity information by tilt of the camera module;
a calculator configured to calculate a ratio of effective focal length relative to a lens moving distance, in a case a lens focal length is changed by the first actuator; and
an amplifier configured to determine a second driving signal amplifying the first driving signal, using the ratio of effective focal length relative to the lens moving distance.
2. The apparatus of claim 1 , further comprising:
an angular velocity sensor configured to detect an angular velocity by the tilt of the camera module.
3. The apparatus of claim 1 , further comprising:
a first driving unit configured to drive the first actuator.
4. The apparatus of claim 3 , wherein the first driving unit provides code information based on lens movement to the calculator.
5. The apparatus of claim 4 , wherein the calculator calculates the ratio of effective focal length relative to the lens moving distance by determining the lens moving distance using the code information based on the lens movement.
6. The apparatus of claim 3 , further comprising:
storage configured to store lens moving distance corresponding to the code information based on the lens movement.
7. The apparatus of claim 6 , wherein the calculator calculates the ratio of effective focal length relative to the lens moving distance by receiving the lens moving distance from the storage.
8. The apparatus of claim 1 , further comprising:
a second driving unit configured to drive the second actuator using the second driving signal.
9. The apparatus of claim 1 , wherein the controller obtains an angle tilted by the camera module by integrating the angular velocity, and determines the first driving signal using a compensation stroke by obtaining the compensation stroke from the tilted angle.
10. A method for compensating image blur caused by hand blur in a camera module including a first actuator for AF (Auto Focus)/zoom, and a second actuator for OIS (Optical Image Stabilizer), the method comprising:
receiving an angular velocity by tilt of the camera module;
determining a first driving signal for driving the second actuator using the angular velocity;
calculating a ratio of effective focal length relative to a lens moving distance using the driving of the first actuator; and
determining a second driving signal amplifying the first driving signal, using the ratio of effective focal length relative to the lens moving distance.
11. The method of claim 10 , wherein the determining the first driving signal comprises:
obtaining an angle tilted by the camera module by integrating the angular velocity;
obtaining a compensation stroke using the tilted angle; and
determining the first driving signal using the compensation stroke.
12. The method of claim 10 , wherein the calculating the ratio comprises:
receiving code information based on the lens movement;
determining the lens moving distance using the code information; and
calculating the ratio of effective focal length relative to the lens moving distance.
13. The method of claim 10 , wherein the calculating the ratio of effective focal length relative to the lens moving distance comprises:
receiving the lens moving distance corresponding to the code information based on the lens movement; and
calculating the ratio of effective focal length relative to the lens moving distance.
14. The method of claim 10 , wherein the second driving signal is determined by the following Math Figure:
Δ V′=ΔV ·(1+Ratio)
where, ΔV′ is the second driving signal, ΔV is the first driving signal, Ratio is a ratio of effective focal length relative to the lens moving distance.
15. The method of claim 10 , further comprising:
driving the second actuator using the first driving signal or the second driving signal.