1. Field of the Invention
The present invention relates to an image sensor, and an image capturing apparatus and a cellular phone using the image sensor.
2. Description of the Related Art
Conventionally, many types of image capturing apparatuses, such as digital cameras and video cameras, using image sensors represented by a CCD and CMOS sensor have been developed, and the number of pixels of the image sensor has been increased in order to obtain a high definition image.
In these image capturing apparatuses, since all the pixels are read out from the image sensor in a still image shooting, a high resolution image can be obtained. On the other hand, it takes time to read out image data from all the pixels of the image sensor, and a frame rate decreases. Moreover, power consumption increases if all the pixels are read out at high speed.
In order to solve the above problem, Japanese Patent Laid-Open No. 09-247689 discloses an image capturing apparatus that takes 4×4 pixels as one unit, and signals of the same color are thinned out and added.
However, according to the technique disclosed in Japanese Patent Laid-Open No. 09-247689, power consumption is reduced by performing thinning readout, but there is no consideration about power consumed by a readout circuit for pixels which are not read out.