Range finder and method for finding range

• US 8,310,585 B2
• Filed: 05/14/2008
• Issued: 11/13/2012
• Est. Priority Date: 05/16/2007
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Lee, Ki Min, Lee, Jun Ki
• Primary Examiner(s): Ye, Lin
• Assistant Examiner(s): Morehead, III, John H
• Application Number:
  US12/600,402
• Publication Number:
  US 20100149407A1
• Time in Patent Office: 1,644 Days
• Field of Search: None
• US Class Current: 348/348
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 17/93 for anti-collision purposes
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4817 relating to scanning

Abstract

Provided is a range finder. The range finder comprises a light-emitting unit, a light-receiving unit, a reflection mirror, an actuator, and a controller. The light-emitting unit emits a light pulse, and a light-receiving unit detects reflected light incident thereto. The reflection minor reflects the light pulse emitted from the light-emitting unit to a measurement space, and reflecting the reflected light reflected by an object in the measurement space so that the reflected light is incident to the light-receiving unit. The actuator allows the reflection minor to move. The controller obtains distance information from a signal detected by the light-receiving unit, and obtains location information from the actuator.

Claims

1. A method for finding a range, the method comprising:

emitting a light pulse to a measurement space and detecting reflected incident light reflected by an object to obtain location information and distance information of the object;

varying a direction in which the light pulse is emitted to obtain location information and distance information of the object;

inputting an operating mode;

varying at least one of a frequency of the light pulse, a displacement velocity in the direction in which the light pulse is emitted, and a displacement range in the direction in which the light pulse is emitted depending on the operating mode to obtain location information and distance information of the object;

performing at least one of decreasing a displacement velocity in a horizontal direction parallel to the direction in which the light pulse is emitted, decreasing a displacement velocity or a displacement range in a vertical direction perpendicular to the direction in which the light pulse is emitted, and decreasing a pulse frequency of the light pulse when the operating mode is a long distance measurement mode; and

performing at least one of increasing a displacement velocity in a horizontal direction parallel to the direction in which the light pulse is emitted, increasing a displacement velocity or a displacement range in a vertical direction perpendicular to the direction in which the light pulse is emitted, and increasing a pulse frequency of the light pulse when the operating mode is a short distance measurement mode.

2. The method according to claim 1, comprising emitting the light pulse to a direction moved to at least one of a first direction and a second direction perpendicular to the first direction to obtain the location information and the distance information of the object.

3. The method according to claim 2, wherein the light pulse moves to one of the first and second directions and then moves to the other direction.

4. The method according to claim 2, wherein the light pulse simultaneously moves to both the first direction and the second direction.

5. The method according to claim 1, wherein a direction in which the light pulse is emitted by a reflection mirror is varied.

6. The method according to claim 1, wherein the location information and the distance information are stored by the frame.

7. The method according to claim 6, comprising obtaining and storing the location information and the distance information for a plurality of frames, and combining the location information and the distance information of the plurality of frames to calculate new location information and new distance information.

8. The method according to claim 7, comprising comparing the location information and the distance information of the plurality of frames to calculate a movement or a moving velocity of an object located in the measurement space.

9. The method according to claim 1, comprising:

inputting an operating mode; and

changing the direction in which the light pulse is emitted every frame when the operating mode is a precise measurement mode; and

maintaining the same direction in which the light pulse is emitted every frame when the operating mode is a movement measurement mode.