Substrate position detection device

A substrate position detection device comprising:

• an irradiator that irradiates a predetermined range of a substrate with a predetermined light;
• an imager that takes an image of the predetermined range of the substrate irradiated with the predetermined light;
• a moving mechanism that causes relative movement of the imager and the substrate;
• and
• a controller that:
• detects a position of the substrate by sequentially executing to a plurality of recognition objects on the substrate:
• a moving process of relatively moving the imager to a position corresponding to a predetermined recognition object among the plurality of recognition objects on the substrate;
• an imaging process of taking an image of the predetermined recognition object under a predetermined imaging condition;
• and
• a recognition process of recognizing the predetermined recognition object based on image data obtained by the imaging process;
• after termination of the imaging process on the predetermined recognition object among the plurality of recognition objects, executes the recognition process on the predetermined recognition object, while executing the moving process of relatively moving the imager to a position corresponding to another recognition object different from the predetermined recognition object;
• and
• when failing to recognize any recognition object that is not sequentially last among the plurality of recognition objects:
• causes the moving mechanism to relatively move the imager to a position corresponding to the recognition object that was not recognized,
• executes a re-imaging process of taking an image of the recognition object again, and
• executes a re-recognition process of recognizing the recognition object based on image data obtained by the re-imaging process.