Infrared sensor module

• US 8,735,824 B2
• Filed: 11/01/2011
• Issued: 05/27/2014
• Est. Priority Date: 11/17/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hong, Jun Pyo, So, Jea Yun, Yoon, Sang Sik
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US13/317,939
• Publication Number:
  US 20120119091A1
• Time in Patent Office: 938 Days
• Field of Search: 356/3.06, 356/3.08, 356/3.11, 250/341.7, 250/349
• US Class Current: 250/341.7
• CPC Class Codes: G01C 3/10 using a parallactic triangle with variable angles and a base of fixed length in the observation station, e.g. in the instrument
• CPC Class Codes: G01S 17/003 Bistatic lidar systems; Multistatic lidar systems
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements

Abstract

An infrared sensor module includes a first infrared sensor that includes a first light emitting unit configured to emit infrared light to an object and a first light receiving unit configured to detect an amount of infrared light reflected from the object, a second infrared sensor that includes a second light emitting unit configured to emit infrared light to the object and a second light receiving unit configured to detect an amount of the infrared light reflected from the object, and a controller to measure reflectivity of the object using a peak output voltage of the first light receiving unit, and to measure a distance to the object using not only the measured object reflectivity but also an output voltage of the second light receiving unit. As a result, the distance from the infrared sensor to the object can be correctly measured irrespective of the reflectivity of the object.

Claims

1. An infrared sensor module comprising:

a first infrared sensor that includes a first light emitting unit configured to emit infrared light to an object and a first light receiving unit configured to detect an amount of an infrared light reflected from the object;

a second infrared sensor that includes a second light emitting unit configured to emit infrared light to the object and a second light receiving unit configured to detect an amount of the infrared light reflected from the object; and

a controller to measure reflectivity of the object using a peak output voltage of the first light receiving unit, and to measure a distance to the object using not only the measured object reflectivity but also an output voltage of the second light receiving unit.

2. The infrared sensor module according to claim 1, wherein the first infrared sensor is arranged at the outside of the second infrared sensor.

3. The infrared sensor module according to claim 1, wherein the controller controls the first light emitting unit to alternately emit infrared light having two or more emission strengths when measuring the object reflectivity.

4. The infrared sensor module according to claim 3, wherein the controller controls the second light emitting unit to emit one strength of infrared light when measuring the distance to the object.

5. The infrared sensor module according to claim 4, further comprising:

a memory to store not only a lookup table that indicates reflectivity corresponding to a peak output voltage of the first light receiving unit in association with emission of the infrared light having two or more emission strengths of the first light emitting unit, but also a distance lookup table that depends upon not only the reflectivity associated with emission of one-strength infrared light of the second light emitting unit but also an output voltage of the second light receiving unit.

6. The infrared sensor module according to claim 5, wherein the controller is configured to measure the object reflectivity using the lookup table on the basis of a peak output voltage of the first light receiving unit in association with emission of the infrared light having two or more emission strengths of the first light emitting unit or using an interpolation method based on the lookup table.

7. The infrared sensor module according to claim 5, wherein the controller is configured to measure the distance to the object using the distance lookup table on the basis of an output voltage of the second light receiving unit in association with emission of the one-strength infrared light of the second light emitting unit or using an interpolation method based on the distance lookup table.

8. The infrared sensor module according to claim 3, wherein the controller controls the second light emitting unit to emit infrared light having two or more emission strengths when measuring the distance to the object.

9. The infrared sensor module according to claim 8, further comprising:

a memory to store not only a lookup table that indicates reflectivity corresponding to a peak output voltage of the first light receiving unit in association with emission of the infrared light having two or more emission strengths of the first light emitting unit, but also a distance lookup table that depends upon not only the reflectivity associated with emission of the infrared light having two or more emission strengths of the second light emitting unit but also an output voltage of the second light receiving unit.

10. The infrared sensor module according to claim 9, wherein the controller is configured to measure the object reflectivity using the lookup table on the basis of a peak output voltage of the first light receiving unit in association with emission of the infrared light having two or more emission strengths of the first light emitting unit or using an interpolation method based on the lookup table.

11. The infrared sensor module according to claim 9, wherein the controller is configured to measure the distance to the object using the distance lookup table on the basis of an output voltage of the second light receiving unit in association with emission of the infrared light having two or more emission strengths of the second light emitting unit or using an interpolation method based on the distance lookup table.

12. An infrared sensor module comprising:

a first infrared sensor that includes a first light emitting unit configured to emit infrared light to an object, and first and second light receiving units configured to detect an amount of the infrared light reflected from the object at a first and second location, respectively; and

a controller to measure reflectivity of the object using a peak output voltage of the first light receiving unit, and to measure the distance to the object using the measured object reflectivity and an output voltage of the second light receiving unit.

13. The infrared sensor module according to claim 12, wherein the first light receiving unit is arranged at the outside of the second light receiving unit.

14. The infrared sensor module according to claim 12, wherein the controller controls the first light emitting unit to alternately emit the infrared light having two or more emission strengths when measuring the object reflectivity.

15. The infrared sensor module according to claim 14, wherein the controller controls the first light emitting unit to emit the infrared light having two or more emission strengths when measuring the distance to the object.

16. An infrared sensor module comprising:

an infrared sensor that includes first and second light emitting units configured to emit infrared light to an object and a first light receiving unit configured to detect an amount of the infrared light reflected from the object; and

a controller to measure reflectivity of the object using a peak output voltage of the first light receiving unit in association with infrared light emission of the first light emitting unit, and to measure the distance to the object using the measured object reflectivity and an output voltage of the first light receiving unit in association with infrared light emission of the second light emitting unit.

17. The infrared sensor module according to claim 16, wherein the first light emitting unit is arranged at the outside of the second light emitting unit.

18. The infrared sensor module according to claim 16, wherein the controller controls the first light emitting unit to alternately emit the infrared light having two or more emission strengths when measuring the object reflectivity.

19. The infrared sensor module according to claim 18, wherein the controller controls the second light emitting unit to emit the one-strength infrared light when measuring the distance to the object.

20. The infrared sensor module according to claim 18, wherein the controller controls the second light emitting unit to emit the infrared light having two or more emission strengths when measuring the distance to the object.