Image forming apparatus, image forming method and image sensor

An image forming method comprising:

• sequentially emitting illuminating light beams from multiple different irradiation directions with respect to an object and irradiating the object with the illuminating light beams;
• capturing a plurality of different images in the multiple different irradiation directions, respectively, using an image sensor which is arranged at a position where the illuminating light beams that have been transmitted through the object are incident;
• forming a high-resolution image of the object, having a higher resolution than any of the plurality of images, based on the plurality of images;
• and
• storing in a memory data about the ratio of light rays that have been incident on a photoelectric conversion section of each pixel of the image sensor to light rays that have passed through the upper surface of a plurality of subpixels included in the pixel with respect to each of the multiple irradiation directions,
• wherein the forming a high-resolution image of the object includes the forming the high-resolution image of the object by multiplying the inverse matrix of a matrix having the ratio as its element by the vector of the pixel values based on the data that has been retrieved from the memory by extracting, as a vector, a set of pixel values associated with the multiple irradiation directions from pixel values that form each of the plurality of images.

An image sensor for use in an image forming apparatus, the image forming apparatus comprising:

• i) an illumination system which sequentially emits illuminating light beams from multiple different irradiation directions with respect to an object and irradiates the object with the illuminating light beams;
• ii) a holder which holds the image sensor in an attachable and removable state;
• iii) an image processing section which forms, based on a plurality of different images that have been captured by the image sensor in the multiple different irradiation directions, respectively, a high-resolution image of the object having a higher resolution than any of the plurality of images;
• and iv) a memory which stores data about the ratio of light rays that have been incident on a photoelectric conversion section of each pixel of the image sensor to light rays that have passed through the upper surface of a plurality of subpixels included in the pixel with respect to each of the multiple irradiation directions, the image processing section forming the high-resolution image of the object based on the data that has been retrieved from the memory by extracting, as a vector, a set of pixel values associated with the multiple irradiation directions from pixel values that form each of the plurality of images,
• the image sensor being arranged attachably to, and removably from, the image forming apparatus,
• an imaging surface of the image sensor has an object supporting portion which is a region on which the object is able to be mounted, and
• the image sensor is arranged at a position where the illuminating light beams transmitted through the object are incident while being held by the holder onto the image forming apparatus and captures the plurality of different images in the multiple different irradiation directions.