Detection device and optical filter

An optical filter comprising:

• a protective film;
• a plurality of first light-blocking layers that are directly formed on the protective film and are arranged in a matrix having a row-column configuration;
• a second light-blocking layer overlapping the first light-blocking layers;
• a plurality of lenses;
• a first light-transmitting resin layer located between the first light-blocking layers and the second light-blocking layer;
• and
• a second light-transmitting resin layer located between the second light-blocking layer and the lenses, wherein
• the first light-blocking layers are arranged so as to be separated from one another by slits between the first light-blocking layers adjacent to each other, the first light-blocking layers being not formed in the slits,
• each of the first light-blocking layers has a plurality of first openings,
• the second light-blocking layer has second openings overlapping the respective first openings, and
• the lenses overlap the respective first openings and the respective second openings.