A photosensor device and an optical pickup device incorporating the photosensor device are advantageously used in an optical compact disc player of the type where the optical pickup device is driven along a path at an acute tilt angle relative to the sides of a rectangular casing. The photosensor has a plurality of photosensitive elements aligned in a first direction and a plurality of terminal leads extending parallel to each other and perpendicular to a second direction so that the photosensor may be mounted on a circuit board in a conventional configuration to save space. Within the optical pickup device, the photosensitive elements are aligned at a mounting angle which is a function of the tilt angle so that the three optical beams are received thereon in the proper orientation.