Electronic distance meter

An electronic distance meter comprising:

• a sighting telescope having an objective lens configured to sight an object;
• a reflection member positioned behind said objective lens;
• an optical distance meter which includes a light-transmitting optical system configured to transmit a measuring light via said reflection member and said objective lens, and a light-receiving optical system configured to receive light which is reflected by said object, subsequently passed through said objective lens and not interrupted by said reflection member;
• a beam-diameter varying device, provided in association with said light-transmitting optical system, configured to vary a beam diameter of said measuring light;
• a controller configured to vary said beam diameter via said beam-diameter varying device in accordance with a distance from said object to said electronic distance meter;
• and
• a light-emitting element which emits said measuring light;
• wherein said beam-diameter varying device comprises a lens, said beam-diameter varying device inserting and retracting said lens into and from an optical path of said light-transmitting optical system in front of said light-emitting element in accordance with said distance.

An electronic distance meter equipped with an autofocus system, comprising:

• a sighting telescope for sighting an object, said telescope including an objective lens and a focusing lens;
• a reflection member positioned behind said objective lens;
• an optical distance meter which includes a light-transmitting optical system for transmitting a measuring light via said reflection member and said objective lens, and a light-receiving optical system for receiving light which is reflected by said object, subsequently passed through said objective lens and eventually not interrupted by said reflection member;
• a beam-diameter varying device, provided in association with said light-transmitting optical system, for varying a beam diameter of said measuring light;
• a focus detecting device for detecting a focus state of said sighting telescope;
• an autofocus drive system which drives said focusing lens to bring said object into focus in accordance with said focus state detected by said focus detecting device;
• and
• a controller which varies said beam diameter via said beam-diameter varying device in accordance with a lens position of said focusing lens which is detected via said autofocus drive system.

An electronic distance meter equipped with an autofocus system, comprising:

• a sighting telescope configured to sight an object, said telescope including an objective lens and a focusing lens;
• a reflection member positioned behind said objective lens;
• an optical distance meter which includes a light-transmitting optical system configured to transmit a measuring light via said reflection member and said objective lens, and a light-receiving optical system configured to receive light which is reflected by said object, subsequently passed through said objective lens and eventually not interrupted by said reflection member;
• a beam-diameter varying device, provided in association with said light-transmitting optical system, configured to vary a beam diameter of said measuring light;
• a focus detecting device configured to detect a focus state of said sighting telescope;
• an autofocus drive system configured to drive said focusing lens to bring said object into focus in accordance with said focus state detected by said focus detecting device;
• a controller configured to vary said beam diameter via said beam-diameter varying device in accordance with a lens position of said focusing lens which is detected via said autofocus drive system;
• and
• a light-emitting element which emits said measuring light;
• wherein said beam-diameter varying device comprises a lens, said beam-diameter varying device inserting and retracting said lens into and from an optical path of said light-transmitting optical system in front of said light-emitting element in accordance with said distance.