Photon counting detector to generate high-resolution images and high-contrast images, and photon counting and detecting method using the same

A photon counting and detecting method in readout circuits to count photons in multi-energy radiation incident to a sensor, the photons being counted with respect to each of a plurality of energy bands of the multi-energy radiation, the method comprising:

• determining an energy band of a photon;
• in response to the determined energy band of the photon being a first predetermined energy band, counting the photon in one of the readout circuits that corresponds to a pixel to which the photon has been incident;
• and
• in response to the determined energy band of the photon being an n-th predetermined energy band, receiving, from all of the readout circuits, comparison results based on the n-th predetermined energy band, and counting the photon of the n-th predetermined energy band.

A photon counting detector, comprising:

• l number of readout circuits, each of which is configured to count photons in multi-energy radiation incident to a sensor, the readout circuits comprising
• m number of first and n-th comparators disposed in respective readout circuits, each of the first comparators configured to compare photons converted by the sensor with a first threshold, and each of the n-th comparators configured to compare the photons with a n-th threshold;
• l number of primary counters disposed in respective readout circuits, each of the primary counters configured to count the photons based on the first threshold;
• and
• m−1 number of secondary counters disposed in at least one of the readout circuits, each of the secondary counters configured to count the photons based on the n-th threshold.