A projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) in a projection system comprising a plurality of projection devices (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) configured to perform position measurement and projection on a target object (105, 106), the projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) comprising: an invisible light projection unit configured to project invisible measurement light onto the target object (105, 106); a light receiving unit configured to receive reflection light of the measurement light, the reflection light being reflected from the target object (105, 106); and a visible light projection unit configured to project a visible light video content on the basis of position information of the target object (105, 106), wherein the projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) projects the measurement light at a different projection timing than other projection devices (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) of the plurality of projection devices do, wherein the projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) further comprises a computing unit configured to calculate the position information of the target object (105, 106) on the basis of the reflection light of the measurement light, wherein the computing unit is configured to perform a computation relating to the position information while an invisible light projection unit of another projection device (100, 100B, 140, 160B, P2) of the plurality of projection devices projects measurement light, and the projection device (100, 100A, 140, 160A, P1) is configured to project the video content, while the computing unit of the other projection device (100, 100B, 140, 160B, P2) performs a computation relating to the position information and calculates a shape and a position of the target object (105, 106). an invisible light projection unit configured to project invisible measurement light onto the target object (105, 106); a light receiving unit configured to receive reflection light of the measurement light, the reflection light being reflected from the target object (105, 106); and a visible light projection unit configured to project a visible light video content on the basis of position information of the target object (105, 106), wherein the projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) projects the measurement light at a different projection timing than other projection devices (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) of the plurality of projection devices do, wherein the projection device (100, 100A, 100B, 140, 160A, 160B, P1, P2, P3) further comprises a computing unit configured to calculate the position information of the target object (105, 106) on the basis of the reflection light of the measurement light, wherein the computing unit is configured to perform a computation relating to the position information while an invisible light projection unit of another projection device (100, 100B, 140, 160B, P2) of the plurality of projection devices projects measurement light, and the projection device (100, 100A, 140, 160A, P1) is configured to project the video content, while the computing unit of the other projection device (100, 100B, 140, 160B, P2) performs a computation relating to the position information and calculates a shape and a position of the target object (105, 106).