Imaging apparatus and method for controlling white balance
View Patent ↗An imaging apparatus has: a white balance control circuit for detecting an achromatic portion of an image of an object and controlling gains of the chrominance; an object distance detecting circuit for detecting a distance to the object; and a zoom value detecting circuit for detecting a zoom value of the optical system. The imaging apparatus further has: an object brightness detecting circuit for detecting brightness of the object; and a white balance control amount adjustment value setting circuit for forming a white balance control amount adjustment value to adjust a control amount in the white balance control circuit on the basis of object brightness information, object distance detection information, and zoom value information, wherein the white balance control amount is adjusted on the basis of the white balance control amount adjustment value.
1. An imaging apparatus, comprising:
object distance detecting means for detecting distance to an object;
zoom value detecting means for detecting zoom value of an optical system;
object brightness detection means for detecting brightness of the object;
white balance controlling means for detecting an achromatic portion of the object based on a chrominance signal generated from an output signal of an imaging element through the optical system, and controlling gain of the chrominance signal in accordance with shift amount of white balance detected from the achromatic portion, wherein:
in cases where object distance detection information is fixed, and
when object brightness information is a first value, while zoom value information changes, on a border of a first threshold value, adjustment of white balance is made operative or stopped, and
when the object brightness information is a second value different from the first value, and when the zoom value information is changed, adjustment of white balance is made operative or stopped on the border of a second threshold value different from the first boundary value.
2. An imaging apparatus according to claim 1 , wherein:
when the object brightness information is the first value, it is controlled so that white balance adjustment is not carried out when the zoom value information is more than the first threshold value, and to adjust white balance when it is less than the first threshold value, and
when the object brightness information is the second value, it is controlled so that white balance is not adjusted when the zoom value information is above the second threshold value, and to control white balance adjustment when it is less than the second threshold value.
3. An imaging apparatus, comprising:
object distance detecting means for detecting distance to an object;
zoom value detecting means for detecting zoom value of an optical system;
object brightness detection means for detecting brightness of the object;
white balance controlling means for detecting an achromatic portion of the object based on a chrominance signal generated from an output signal of an imaging element through the optical system, and controlling gain of the chrominance signal in accordance with shift amount of white balance detected from the achromatic portion, wherein:
in cases where object distance detection information is fixed, and
when zoom value information is a first value, and object brightness information is to be changed, on a border of a first threshold value, adjustment of white balance is made operative or stopped, and
when the zoom value information is a second value different from the first value, and when the object brightness information is changed, on a border of a second threshold value different from the first threshold value, adjustment of white balance is made operative or stopped.
4. An imaging apparatus according to claim 3 , wherein:
when the zoom value information is the first value, it is controlled so that adjustment of white balance is carried out when the object brightness information is larger than the first threshold value, and not to adjust white balance when it is less than the first threshold value, and
when the zoom value information is the second value, it is controlled so that adjustment of white balance is carried out when the object brightness information is larger than the second threshold value, and not to adjust white balance when it is less than the second threshold value.
5. An imaging apparatus, comprising:
object distance detecting means for detecting distance to an object;
zoom value detecting means for detecting zoom value of an optical system;
object brightness detecting means for detecting brightness of the object;
white balance controlling means for detecting an achromatic portion of the object based on a chrominance signal generated from an output signal of an imaging element through the optical system, and controlling gain of the chrominance signal in accordance with shift amount of white balance detected from the achromatic portion, wherein:
in cases where the zoom value is fixed, and
when object distance detection information is a first value, while object brightness information changes, on a border of a first threshold value, adjustment of white balance is made operative or stopped, and
when the object distance detection information is a second value different form the first value, and when the object brightness information is changed, adjustment of white balance is made operative or stopped on a border of a second threshold value different from the first threshold value.
6. An imaging apparatus according to claim 5 , wherein:
when the object distance detection information is a first value, it is controlled so that adjustment of white balance is carried out when the object brightness information is larger than the first threshold value, and adjustment of white balance is not carried out when it is less than the first threshold value, and
when the object distance detection information is the second value, it is controlled so that adjustment of white balance is carried out when the object brightness information is larger than the second threshold value, and adjustment of white balance is not carried out when it is less than second threshold value.
7. An imaging apparatus, comprising:
object distance detecting means for detecting distance to an object;
zoom value detecting means for detecting zoom value of an optical system;
object brightness detecting means for detecting brightness of the object;
white balance controlling means for detecting an achromatic portion of the object based on a chrominance signal generated from an output signal of an imaging element through the optical system, and controlling gain of the chrominance signal in accordance with shift amount of white balance detected form the achromatic portion, wherein:
in cases where the zoom value is fixed, and
when object brightness information is a first value, while object distance detection information changes, on a border of a first threshold value, adjustment of white balance is made operative or stopped, and
when the object brightness information is a second value different from the first value, and when the object distance detection information is changed, adjustment of white balance is made operative or stopped on a border of a second threshold value different from the first threshold value.
8. An imaging apparatus according to claim 7 , wherein:
when the object brightness information is a first value, it is controlled so that adjustment of white balance is carried out when the object distance detection information is larger than the first threshold value, and not to carry out adjustment of white balance when it is less than the first threshold value, and
when the object brightness information is a second value, it is controlled so that adjustment of white balance is carried out when the object distance detection information is larger than the second threshold value, and adjustment of white balance is not carried out when it is less than the second threshold value.