Electric distance meter

An electric distance meter, which measures a distance to an object, comprising:

• a light receiving and emitting mechanism configured to emit light from a light source and receive light by a light receiver;
• an optical path forming optical system configured to form an emission optical path which emits outgoing light from the light receiving and emitting mechanism from an objective lens on an irradiation optical axis toward the object and form a reflection optical path which guides reflection light of the outgoing light from the object entered onto the objective lens to the light receiving and emitting mechanism in a sate without having a central portion, which circularly surrounds the outgoing light;
• an emitting optical fiber configured to connect the light receiving and emitting mechanism and the optical path forming optical system, and guide the outgoing light emitted from the light receiving and emitting mechanism to the emission optical path of the optical path forming optical system;
• and
• a light-receiving optical fiber configured to connect the light receiving and emitting mechanism and the optical path forming optical system, and guide the reflection light via the reflection optical path of the optical path forming optical system to the light receiver of the light receiving and emitting mechanism, wherein
• the reflection optical path includes a reflection light collimator optical member configured to convert the reflection light into a substantial parallel light beam and a condensing optical member configured to condense the reflection light via the reflection light collimator optical member to be entered onto an incident end face of the light-receiving optical fiber, and
• a cone prism configured to change a cross-section shape of a light beam while reducing an outer diameter of the light beam without generating a transmission deflection angle is provided between the reflection light collimator optical member and the condensing light optical member.

An electric distance meter, which measures a distance to an object, comprising:

• a light receiving and emitting mechanism configured to emit light from a light source and receive light by a light receiver;
• an optical path forming optical system configured to form an emission optical path which emits via the objective lens outgoing light from the light receiving and emitting mechanism to surround an irradiation optical axis toward the object, and to form a reflection optical path which guides the reflection light from the object entered onto the objective lens near the irradiation optical axis to be surrounded by the outgoing light to the light emitting and receiving mechanism;
• an emitting optical fiber configured to connect the light receiving and emitting optical mechanism and the optical path forming optical system and guide the outgoing light emitted from the light receiving and emitting mechanism to the emission optical path of the emission optical system;
• a light-receiving optical fiber configured to connect the light receiving and emitting optical mechanism and the optical path forming optical system and guide the reflection light via the reflection optical path of the light receiving optical system to the light receiver of the light receiving and emitting mechanism, wherein
• the emission optical path includes an outgoing light collimator optical member configured to convert the emission light into a parallel light beam, and
• the cone prism configured to convert the emission light via the outgoing light collimator optical member into a parallel light beam without having a central portion by changing a cross-section shape of the light beam while increasing an outer diameter of the light beam without generating a transmission deflection angle is provided between the outgoing light collimator optical member and the objective lens.