A detection device that is configured to detect light emitted onto a detection target object , the detection device comprising: a first light source that is configured to emit light onto the detection target object from a first direction; a second light source that is configured to emit light onto the detection target object from a second direction; a detecting section for detecting light emitted from the first light source and light emitted from the second light source , wherein the detecting section is a single camera ; a first guiding member that is configured to guide light, emitted from the first light source onto the detection target object , to the detecting section via a first light path for imaging the detection target object from the first direction; and a second guiding member that is configured to guide light, emitted from the second light source onto the detection target object , to the detecting section via a second light path for imaging the detection target object from the second direction; the detection device being characterized by the first light path and the second light path being different, and a light-blocking member that is configured to block light emitted from the first light source such that light emitted from the first light source does not arrive at the detecting section along the second light path, while allowing light emitted from the second light source to arrive at the detecting section along the second light path, wherein the light-blocking member comprises a first light-blocking block , which is provided between the second light source and the detection target object , and a second light-blocking block , which is provided between the detection target object and the second guiding member , wherein slits are formed respectively in the first light-blocking block and the second light-blocking block , and match the direction of light emitted from the second light source . a first light source that is configured to emit light onto the detection target object from a first direction; a second light source that is configured to emit light onto the detection target object from a second direction; a detecting section for detecting light emitted from the first light source and light emitted from the second light source , wherein the detecting section is a single camera ; a first guiding member that is configured to guide light, emitted from the first light source onto the detection target object , to the detecting section via a first light path for imaging the detection target object from the first direction; and a second guiding member that is configured to guide light, emitted from the second light source onto the detection target object , to the detecting section via a second light path for imaging the detection target object from the second direction; the detection device being characterized by the first light path and the second light path being different, and a light-blocking member that is configured to block light emitted from the first light source such that light emitted from the first light source does not arrive at the detecting section along the second light path, while allowing light emitted from the second light source to arrive at the detecting section along the second light path, wherein the light-blocking member comprises a first light-blocking block , which is provided between the second light source and the detection target object , and a second light-blocking block , which is provided between the detection target object and the second guiding member , wherein slits are formed respectively in the first light-blocking block and the second light-blocking block , and match the direction of light emitted from the second light source . <EOS>