Abstract:
Image pickup systems capable of preventing blurred images are provided, in which a first sensor detects a variation in inclination of an image pickup device to generate a first sensing data, a second sensor detects a position movement from an image sensor in the image pickup device to generate a second sensing data and a driving unit is coupled to the image sensor. A processing module receives the first and second sensing data, integrates the first sensing data, calculates the integrated first sensing data and the second sensing data to obtain control information, and enables the driving unit to adjust the position of the image sensor according to the control information.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to image pickup systems, and in particular to an image pickup system which integrates a data sensed by an angular velocity signal to compensate vibration. 
   2. Description of the Related Art 
   Recently, digital cameras have become a part of every day life, due to ease of use when reviewing and processing captured images in related devices such as computers. 
   Vibration occurs with all cameras, particularly light and thin digital cameras. Since the hand is often unstable when taking pictures, most cameras contend with unsteady focus due to vibration prior to or at the moment of image capture, resulting in image blur. Thus, anti-vibration mechanisms are always provided in digital cameras. 
   United State patent publication (2005/0031326) and two Japan patents (H08-136962 and H11-308521) recited within, utilizing a position sensor to detect position movement of the image sensor and a gyro sensor to detect angular velocity to adjust for vibration. The digital camera processor calculates a compensation value according to the detected data to move a compensation lens in the digital camera by a driver for vibration compensation, thereby preventing blurred images caused by camera vibrations. However, excessive movement of a lens to adjust for vibration can cause damage between lenses. 
   BRIEF SUMMARY OF THE INVENTION 
   Embodiments of an image pickup system are provided, in which a first sensor detects a variation in inclination of an image pickup device to generate a first sensing data, a second sensor detects a position movement from an image sensor in the image pickup device to generate a second sensing data and a driving unit is coupled to the image sensor. A processing module receives the first and second sensing data, integrates the first sensing data, calculates the integrated first sensing data and the second sensing data to obtain control information, and enables the driving unit to adjust the position of the image sensor according to the control information. 
   The invention provides another embodiment of a method for pickup images, in which a variation in inclination of an image pickup device is detected to generate a first sensing data by a first sensor and a position movement from an image sensor in the image pickup device is detected to generate a second sensing data by a second sensor. The first sensing data is integrated, and the integrated first sensing data and the second sensing data obtains control information which is calculated, and a driving unit is enabled to adjust the position of the image sensor according to the control information. 
   The invention provides another embodiment of an image pickup system, in which a gyro sensor detects a variation in inclination of an image pickup device to generate an angular velocity signal of the image pickup device, and a Hall effect sensor detects a position movement from an image sensor in the image pickup device to generate a position signal of the image sensor. A processing module comprises an integrator integrating the angular velocity signal, a combination unit processing the integrated angular velocity signal and the position signal to output a combined data, and a proportional-integral-derivative (PID) controller generating control information according to the combined data. A driver control unit generates a corresponding control signal according to the control information, and a driving unit adjusting the position of the image sensor according to the corresponding control signal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
       FIG. 1  shows an embodiment of an image pickup system; 
       FIG. 2  shows a flowchart of the image pickup method in the embodiment; 
       FIG. 3A  shows a relationship between an angular signal of an image pickup device; 
       FIG. 3B  shows a relationship between variations in angular velocity of the image pickup device and time; 
       FIG. 3C  shows a relationship between variations in angular acceleration and time; 
       FIG. 4A  shows a relationship between variations in position of the image sensor and time; 
       FIG. 4B  shows a relationship between variations in movement velocity of the image sensor and time; and 
       FIG. 4C  shows a relationship between variations in movement acceleration of the image sensor and time. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
     FIG. 1  shows an embodiment of an image pickup system. The image pickup system  100  can be implemented as an image pickup device with vibration compensation. An example using an image pickup system includes a digital camera but is not limited thereto. As shown, the image pickup system  100  comprises a gyro sensor  10 , a Hall effect sensor  20 , a processing module  30 , a driving unit  40 , an image sensor  50 , a high pass filter  60  and amplifiers  70 A and  70 B. 
   The gyro sensor  10  can be disposed in the image pick device to detect variations in inclination and generate corresponding sensing data. For example, the gyro sensor  10  generates an angular velocity signal of the image pickup device, the angular velocity signal can be variations in an angular velocity ({right arrow over (ω)}) under different times as shown in  FIG. 3B , or can be variations in an angular acceleration ({right arrow over (a)}) under different times as shown in  FIG. 3C . 
   The Hall effect sensor  20  can be disposed adjacent to the image sensor  50  to detect position movement of the image sensor  50  and generate sensing data accordingly. For example, the Hall effect sensor  20  generates a position signal of the image sensor  50 . The position signal can be variations in position (p) of the image sensor  50  under different times as shown in  FIG. 4A , or variations in movement velocity ({right arrow over (v)}) of the image sensor  50  under different times as shown in  FIG. 4B . 
   The processing module  30  comprises analog-to-digital converters (ADC)  41 A and  41 B, an integrator  42 , a phase compensation unit  43 , a combination unit  44 , proportional integral derivative (PID) controllers  45 A and  45 B, a selection unit  46 , a driver controller  47 , a pulse width modulator (PWM)  48  and a general purpose input/output (GPIO) terminal  49 . The processing module  30  is coupled to the gyro sensor  10 , the hall effect sensor  20  and the driving unit  40 , integrating the angular velocity signal and calculating control information according to the integrated angular velocity signal and the position signal, such that the driving unit  40  adjusts the position of the image sensor  50  in an image pickup device according to the control information. 
   In the embodiment, the gyro sensor  10  detects variations in inclination of the image pickup device to generate corresponding data output to the high pass filter  30 , thereby eliminating signal shifts or unwanted signals. Then, the filtered signal is transmitted to the ADC converter  41 A in the processing module  30  after being amplified by an amplifier  70 A. The ADC  41 A  30  converts the amplified signal from the amplifier  70 A into sensing data S 1  and transmits sensing data S 1  to the integrator  42  and the phase compensation unit  43 . It should be noted that the digital signal from the ADC  41 A is also output to the compensation unit  43  for phase compensation and outputs corresponding phase compensation data to the combination unit  44 . 
   In addition, as the amplifier  70 B amplifies the Hall effect sensor  20  signal, the amplifier  70 B can be integrated into the Hall effect sensor  20  but is not limited thereto. For example, the signal outputted from the amplifier  70 B is outputted to the other ADC  41 B, such that the signal sensed by the Hall effect sensor  20  is converted into digital sensor data S 2  and outputted to the combination unit  44  and the PID controller  45 B. The PID controller  45 B generates corresponding information I 2  according to the received data. 
   Further, after integrating the sensing data S 1 , the integrator  42  provides the integrated sensing data S 11  to the combination unit  44 . The combination unit  44  combines the integrated sensing data S 11 , the phase compensation data S 3  and the sensing data S 2  to obtain a combined data S 4  output to the PID controller  45 A, thereby generating corresponding information I 1 . 
   It should be noted that the information I 1  and I 2  output from PID controllers  45 A and  45 B are transferred to a selection unit  46 , such as a multiplexer. For example, when powering on, the image pickup device can preset the information I 2  to serve as the initial compensation setting of the control information C 1  and transfer it to the driver controller  47  for vibration compensation. The image pickup can also select the information I 1  to serve as the control information C 1  according to the user&#39;s option and transfer it to the driver controller  47  for vibration compensation. 
   Driver controller  47  receives the control information C 1  from the selection device  46  and outputs pulse width modulation signal AS and direction control signal DS to the driving unit  40  through the pulse width modulator  48  and the GIPO terminal  49 . 
   The driving unit  40  is coupled to the image sensor  50 , to receive the pulse width modulation signal AS and direction control signal DS thereafter outputting a control signal to adjust the position of the image sensor  50 . It should be noted that the driving unit in the embodiment is not limited to any type, the driving unit  40  can, for example, be one of a coil driving unit, a piezoelectric actuator or a step motor, used to move the position of the image sensor  50  in the image pickup device. 
   The control signal from the driver controller  47  can be different depending on the design of the driving unit  40 . For example, the control signal can be a control voltage for the driving unit  40 , such that the driving unit  40  can adjust the image sensor  50  at different levels according to different pulse frequencies or different pulse widths. 
   Image sensor  50  can be CCD or a CMOS disposed on a support frame (not shown) which can move up, down, left or right, to pick up images. For example, the moveable support frame can adjust the position of the image sensor  50  in the image pickup device to compensate for vibration thereby preventing blurred images 
   The invention also provides an embodiment of an image pickup method.  FIG. 2  shows a flowchart of the image pickup method in the embodiment. 
   In step S 10 , a variation in inclination of the image pickup device is detected to generate sensing data by a gyro sensor  10 . Next, the gyro sensor  10  outputs an angular velocity signal of the image pickup device, i.e., variations in angular velocity under different times as shown in  FIG. 3B  or variations in angular acceleration under different times as shown in  FIG. 3C . It should be noted that the signal detected by the gyro sensor  10  is transmitted to the high pass filter to remove signal shifts or unwanted signal components and then is amplified by the amplifier  70 A. The amplified signal (i.e. the signal detected by the gyro sensor  10 ) is converted to a digital signal S 1  by the ADC  41 A and transmitted to the integrator  42  and the phase compensation unit  43 . 
   In step S 20 , the position variations of the image sensor  50  in the image pickup device is detected by a Hall effect sensor  20  and generates corresponding data accordingly. Next, the Hall effect sensor  20  generates a position signal of the image sensor  50 , i.e., position variations under different times shown in  FIG. 4A , or velocity variations under different times as shown in  FIG. 4B . The signal detected by the Hall effect sensor  20  is amplified by the amplifier  70 B, then converted into a digital sensing data S 2  by the ADC  41 B and transmitted to the combination unit  44  and the PID controller  45 B. 
   In step S 30 , the sensing data S 1  from the ADC  41 A is integrated by the integrator  42  and the integrated sensing data S 11  is transmitted to the combination unit  44 . In addition, the sensing data S 1  from the ADC  41 A is also processed by a phase compensation unit  43  to provide corresponding phase compensation data S 3  to the combination unit  44 . 
   In step S 40 , integrated sensing data S 11 , sensing data S 2  and phase compensation data S 3  are combined by the combination unit  44 , thereby obtaining control information CI. It should be noted that the combined data from combination unit  44  is processed by the PID controller  45 A to obtain information I 1  and the sensing data S 2  from the ADC  41 B is processed by the PID controller  45 B to obtain information I 2 . The respective information I 1  and I 2  output from the PID controllers  45 A and  45 B is transferred to the selection unit  46  and the information I 1  and I 2  is output as control information CI under different conditions. For example, when powering on, the image pickup device can preset information I 2  to function as the initial compensation setting of control information C 1  for vibration compensation. In addition, the information I 1  can also be selected to function as control information C 1  for vibration compensation according to user&#39;s options. 
   It should be noted that the signal sensed by the gyro sensor  10  can comprises variations in an angular velocity ({right arrow over (ω)}) under different times as shown in  FIG. 3B , or variations in an angular acceleration ({right arrow over (a)}) under different times as shown in  FIG. 3C . Further, the signal sensed by the Hall effect sensor  20  can comprise variations in position (p) of the image sensor  50  under different times as shown in  FIG. 4A , or variations in movement velocity ({right arrow over (v)}) of the image sensor  50  under different times as shown in  FIG. 4B . Thus, there are at least three methods to obtain the combined data S 4  of the combination unit  44  in the embodiment. 
   If the sensing signal sensed by the gyro sensor  10  is variations in an angular velocity ({right arrow over (ω)}) shown in  FIG. 3B  and the signal sensed by the Hall effect sensor  20  is variations in position (p) of the image sensor  50  shown in  FIG. 4A , the angular velocity signal sensed by the gyro sensor  10  is integrated by integrator  42  to become an angular signal shown in  FIG. 3A . The angular signal and the position movement sensed by the Hall effect sensor are combined (or compared) to obtain the combined data S 4 . 
   Alternately, if the signal sensed by the Hall effect sensor  20  is variations in movement velocity ({right arrow over (v)}) of the image sensor  50  shown in  FIG. 4B , variations in an angular acceleration ({right arrow over (a)}) sensed by the gyro sensor  10  is integrated by the integrator  42  to become the angular velocity signal shown in  FIG. 3A . The angular velocity signal and the movement velocity sensed by the Hall effect sensor are combined (or compared) to obtain the combined data S 4 . 
   Moreover, if the signal sensed by the gyro sensor  10  is variations in an angular acceleration ({right arrow over (a)}) under different times as shown in  FIG. 3C  and the signal sensed by the Hall effect sensor  20  is variations in position (p) of the image sensor  50  shown in  FIG. 4A , variations in an angular acceleration ({right arrow over (a)}) sensed by the gyro sensor  10  is integrated trice by the integrator  42  to become the angular velocity signal shown in  FIG. 3A . The angular velocity signal and the movement velocity sensed by the Hall effect sensor are combined (or compared) to obtain the combined data S 4 . 
   In step S 50 , position of the image sensor  50  is adjusted by the driving unit  40  according to the control information CI. For example, the driver controller  47 , according to the control information CI, controls the pulse width modulator  48  and the GPIO terminal  49  to output a pulse width modulation signal AS and a direction signal DS to function as the control signal for adjusting the position of the image sensor  50 . 
   It should be note that the driving unit in the embodiment is not limited to any type, and the driving unit  40  can, for example, be one of a coil driving unit, a piezoelectric actuator or a step motor used to move the position of the image sensor  50  in the image pickup device. The control signal from the driver controller  47  can be different depending on the design of the driving unit  40 . For example, the control signal can be a control voltage for the driving unit  40 , wherein according to different pulse frequencies or different pulse widths, the driving unit  40  will adjust the image sensor  50  at different levels. 
   While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.