Control circuit for image-capturing device
View Patent ↗Performing data processing more effectively for camera shake correction is desirable. Movement of an image-capturing device is compensated on the basis of displacement velocity of the image-capturing device detected by a displacement velocity detector and position regarding a focus adjustment member of the image-capturing device detected by a position detector. An input data format converter converts the displacement velocity detected at the displacement velocity detector from fixed-point format to floating-point format and converts the detected position of the focus member to floating-point data. Furthermore, a gyro filter uses data processing in floating-point format to calculate displacement data for a required amount the image-capturing device is to be displaced and a Hall filter uses data processing in floating-point format to generate drive data for the focus adjustment member. Then, the drive data in floating-point format from the Hall filter is converted to drive data in fixed-point format.
1. An image-capturing control device for calculating drive data for a focus adjustment member to compensate for movement of an image-capturing device on the basis of a displacement velocity of the image-capturing device detected by a displacement velocity detector and a position of the focus adjustment member of the image-capturing device detected by a position detector, the image-capturing control device comprising:
a first input data format converter for converting fixed-point format data regarding displacement velocity detected in said displacement velocity detector to displacement velocity data in floating-point format;
a displacement calculation circuit for calculating displacement data for a required amount said image-capturing device is to be displaced by data processing in floating-point format from displacement velocity data in floating-point format;
a second input data format converter for converting the position of the focus adjustment member detected by said position detector to position data in floating-point format;
a drive data generation circuit for generating drive data for said focus adjustment member by data processing in floating-point format of position data of said focus adjustment member in floating-point format and said displacement data in floating-point format; and
an output data format conversion circuit for converting drive data in floating-point format to drive data in fixed-point format.
2. The control circuit for image-capturing device according to claim 1 , wherein:
said first input data format conversion circuit and said second input data format conversion circuit are composed utilizing one data format conversion circuit in time division.
3. The control circuit for image-capturing device according to claim 2 , wherein:
detection signals regarding analog displacement velocity and position are output from said displacement velocity detector and said position detector, the detection signals are converted from analog to digital in time division by an A/D converter to yield fixed-point format displacement velocity data and position data; and
the obtained fixed-point format displacement velocity data and position data are sequentially supplied to said first input data format converter and said second input data format converter.
4. The control circuit for image-capturing device according to claim 1 , wherein:
said displacement velocity detector is a gyro sensor.
5. The control circuit for image-capturing device according to claim 1 , wherein:
said focus adjustment member is an optical lens; and
said position detector is a Hall sensor for detecting a position of said optical lens.
6. The control circuit for image-capturing device according to claim 4 , wherein:
said gyro sensor outputs an angular velocity Dω;
said displacement calculation circuit integrates said angular velocity Dω, calculates a data Dθ regarding a vibration angle around the x axis and the y axis, and calculates on the basis of this a displacement data Ds, which is an amount the image-capturing device is to be displaced in the x axis and the y axis directions.
7. The control circuit for image-capturing device according to claim 6 , wherein:
said drive data generation circuit adds displacement data Ds in the x axis and y axis directions to the position in said x axis and y axis directions detected by said position detection circuit, respectively, to calculate said drive data in the x axis and y axis directions.