An image sensor has a plurality of pixels arranged in an array on an imaging surface and converts a captured optical image into an image signal. A modulator is provided on a light receiving surface of the image sensor and modulates the light intensity using a grating pattern. An image processor performs image processing of the image signal output from the image sensor. The modulator has a grating substrate and a first grating pattern is formed on a first side of the grating substrate adjacent to a light receiving side of the image sensor. The grating pattern is composed of a plurality of concentric circle patterns. Each concentric circle pattern has concentric circles having a pitch which becomes smaller in inverse proportion to the distance from the center thereof. The plurality of concentric circle patterns do not overlap with each other in the grating pattern.