# US 5,243,398 A · Surveying instrument including low power light plane generator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,243,398 A - Document ID: US5243398A - Status: Granted - Kind: A - Application number: 07/657,097 - Filed: 1991-02-15 - Granted: 1993-09-07 - Earliest claimed: 1991-02-15 - Assignees: Laser Alignment, Inc. - Inventors: Edward G. Nielsen - Web page: https://patentgrep.com/patent/US5243398A ## CPC - G01C 15/002: {Active optical surveying means (optical plumbing G01C15/105)} - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) ## Abstract A surveying instrument is provided which includes an optical sighting scope having a sighting barrel and orthogonal reticular lines visible to an observer viewing through the barrel, in combination with a miniature light plane generator that is oriented to produce a plane of light that is coincident with one of the reticular lines in the direction viewed by an observer viewing through the barrel of the optical sighting scope. The miniature light plane generator includes a laser diode that generates a beam of light, a collimating lens positioned within the beam of light generated by the laser diode in order to produce a beam of collimated light, and a fan lens positioned within the beam of collimated light in order to divert the beam of light into a plane. The miniature generator additionally includes a power supply that supplyies power at a low duty cycle. Because of the resulting reduction in electrical power required by the generator, the components making up the generator, including a battery for supplying energy to the power supply, may be combined within the housing of the optical sighting scope in order to provide a compact instrument. ## Claims ### Claim 1 A surveying apparatus for use by an observer, comprising: an optical sighting scope including a barrel and means defining orthogonal reticular lines visible to an observer viewing through said barrel; a first light generator including a light emitter and optical system adapted to generating and projecting a datum plane of light to coincide with one of said reticular lines in the direction viewed by an observer viewing through said barrel; and a second light generator including a second light emitter and optical system adapted to generating and projecting a datum plane of light to coincide with the other one of said reticular lines in the direction viewed by an observer viewing through said barrel. ### Claim 2 (depends on 1) The surveying apparatus in claim 1 further including optic means positioned in said barrel to project the plane of light generated by one of said first and second laser generators along said barrel away from the observer. ### Claim 3 (depends on 2) The surveying apparatus in claim 2 wherein said optic means includes a beam splitter. ### Claim 4 (depends on 1) The surveying apparatus in claim 1 further including optic means positioned in said barrel to project the plane of light generated by each of said first and second laser generators along said barrel away from the observer. ### Claim 5 (depends on 4) The surveying apparatus in claim 4 wherein said optic means includes a pair of beam splitters. ### Claim 6 (depends on 1) The surveying apparatus in claim 1 wherein each of said first and second light generators is positioned to project their respective plane of light substantially perpendicular the axis of said barrel. ### Claim 7 (depends on 1) The surveying apparatus in claim 1 wherein each of said first and second light generators include: a laser diode that generates a beam of light; and a fan lens positioned within said beam of light; and power supply means for supplying power to said laser diode. ### Claim 8 (depends on 7) The surveying apparatus in claim 7 wherein said power supply means supplies power to said laser diode at a low duty cycle. ### Claim 9 A surveying apparatus for use by an observer, comprising: a housing and means defining an optical passage through said housing; means defining orthogonal reticular lines observable by an observer viewing along a line of sight through said optical passage; a miniature light generator positioned in said housing for generating a datum plane of light transverse said optical passage; and optical means in said passage for diverting said plane of light in the direction of said line of sight of said observer and coincident with one of said reticular lines along said line of sight. ### Claim 10 (depends on 9) The surveying apparatus in claim 9 wherein said miniature light generator includes: a laser diode that generates a beam of light; a collimating lens positioned within the beam of light generated by said laser diode in order to produce a beam of collimated light; a fan lens positioned within said beam of collimated light; and power supply means for supplying power to said laser diode. ### Claim 11 (depends on 10) The surveying apparatus in claim 10 wherein said power supply means supplies power to said laser diode at a low duty cycle. ### Claim 12 (depends on 10) The surveying apparatus in claim 10 wherein said power supply includes a battery positioned in said housing. ### Claim 13 (depends on 9) The surveying apparatus in claim 9 wherein said optical means includes a beam splitter positioned in said passage. ### Claim 14 (depends on 9) The surveying apparatus in claim 9 further including another miniature light generator positioned in said housing for generating another datum plane of light transverse said optical passage and wherein said optical means diverts said another plane of light in said direction of said line of sight of said observer and coincident with the other one of said reticular lines along said line of sight. ### Claim 15 (depends on 14) The surveying apparatus in claim 14 wherein said light generators are angularly offset from each other 90 degrees with respect to said line of sight of said observer. ### Claim 16 (depends on 14) The surveying apparatus in claim 14 wherein said optical means includes a pair of beam splitters, each of said beam splitters positioned to divert one of said planes of light in said direction of said line of sight of said observer. ### Claim 17 (depends on 14) The surveying apparatus in claim 14 wherein each of said miniature light generators includes: a laser diode that generates a beam of light; a collimating lens positioned within the beam of light generated by said laser diode in order to produce a beam of collimated light; a fan lens positioned within said beam of collimated light; and power supply means for supplying power to said laser diode. ### Claim 18 (depends on 17) The surveying apparatus in claim 17 further including a battery in said housing for supplying electrical energy to said power supply means. ### Claim 19 (depends on 17) The surveying apparatus in claim 17 wherein said power supply means supplies power to said laser diode at a low duty cycle.