System including distance sensor for non-contact temperature sensing

• US 9,891,110 B1
• Filed: 03/26/2015
• Issued: 02/13/2018
• Est. Priority Date: 08/07/2014
• Status: Active Grant

• Current Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Original Assignee: Maxim Integrated Products, Inc. (Analog Devices, Inc.)
• Inventors: Pei, Cheng-Wei, Emadi, Arvin
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): Cotey, Philip
• Application Number:
  US14/669,335
• Time in Patent Office: 1,055 Days
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: G01J 5/0275 Control or determination of height or distance or angle information for sensors or receivers

Abstract

A system includes a temperature sensor and a distance sensor. The distance sensor provides an indication of distance between the temperature sensor and an object to be measured. By determining the distance between the temperature sensor and the object, the system determines whether the object is sufficiently close to the temperature sensor to make an accurate temperature measurement, such as by determining whether the object completely fills the field of view of the sensor. In an implementation, the distance sensor includes a light source and a photodetector configured to detect light having wavelengths that correspond to those generated by the light source.

Claims

1. A system configured for non-contact temperature measurements, comprising:

a non-contact temperature sensor configured to measure electromagnetic radiation exchange between the non-contact temperature sensor and an object to be measured;

a distance sensor configured to measure a distance between the distance sensor and the object to be measured; and

control circuitry configured to determine whether the distance measured is within a threshold distance, the control circuitry configured to determine the threshold distance responsive to receipt of input of a target class of the object to be measured, the target class associated with a target threshold distance based on an emissivity of the target class.

2. The system as recited in claim 1, wherein the distance sensor includes a light source configured to generate light having a particular spectrum of wavelengths and a photodetector sensitive to the particular spectrum of wavelengths.

3. The system as recited in claim 1, wherein the non-contact temperature sensor includes a thermopile.

4. The system as recited in claim 1, wherein the electromagnetic radiation includes infrared radiation.

5. The system as recited in claim 1, wherein the threshold distance corresponds to a distance determined to provide an accurate temperature measurement from the non-contact temperature sensor based upon a field of view of the non-contact temperature sensor.

6. The system as recited in claim 1, wherein when the distance measured is within the threshold distance, the control circuitry is configured to direct the non-contact temperature sensor to perform a measurement of electromagnetic radiation exchange between the non-contact temperature sensor and the object.

7. The system as recited in claim 1, wherein when the distance measured is not within the threshold distance, the control circuitry is configured to direct the non-contact temperature sensor to perform a measurement and is configured to direct a user interface to display a potential inaccuracy of the measurement of the non-contact temperature sensor.

8. The system as recited in claim 7, wherein the inaccuracy is due to a limitation of the field of view of the non-contact temperature sensor.

9. The system as recited in claim 1, wherein when the distance measured is not within the threshold distance, the control circuitry is configured to direct a user interface to display a request to bring the distance sensor and the object closer in proximity.

10. A method for non-contact temperature measurement, comprising:

measuring a distance between a distance sensor and an object;

determining a threshold distance between the object and a non-contact temperature sensor responsive to receipt of input of a target class of the object to be measured, the target class associated with a target threshold distance based on an emissivity of the target class;

determining whether the measured distance is within the threshold distance; and

when the measured distance is determined to be within the threshold distance, directing a non-contact temperature sensor to measure electromagnetic radiation exchange between the non-contact temperature sensor and the object.

11. The method as recited in claim 10, wherein the threshold distance corresponds to a distance determined to provide an accurate temperature measurement from the non-contact temperature sensor based upon a field of view of the non-contact temperature sensor.

12. The method as recited in claim 10, further comprising:

when the distance measured is not within the threshold distance, directing the non-contact temperature sensor to measure electromagnetic radiation exchange between the non-contact temperature sensor and the object; and

directing a user interface to display a potential inaccuracy of the measurement of the non-contact temperature sensor.

13. The method as recited in claim 12, wherein the inaccuracy is due to a limitation of the field of view of the non-contact temperature sensor.

14. The method as recited in claim 10, further comprising:

when the distance measured is not within the threshold distance, directing a user interface to display a request to bring the distance sensor and the object closer in proximity.

15. A system configured for non-contact temperature measurements, comprising:

a non-contact temperature sensor configured to measure electromagnetic radiation exchange between the non-contact temperature sensor and an object to be measured;

a distance sensor configured to measure a distance between the distance sensor and the object to be measured, the distance sensor including a camera configured to detect a pulse signal from the object; and

control circuitry configured to determine whether the distance measured is within a threshold distance, the control circuitry configured to determine the threshold distance responsive to receipt of input of a target class of the object to be measured, the target class associated with a target threshold distance based on an emissivity of the target class.

16. The system as recited in claim 15, wherein when the distance measured is within the threshold distance, the control circuitry is configured to direct the non-contact temperature sensor to perform a measurement of electromagnetic radiation exchange between the non-contact temperature sensor and the object.

17. The system as recited in claim 15, wherein when the distance measured is within the threshold distance and the pulse signal is detected, the control circuitry is configured to direct the non-contact temperature sensor to perform a measurement of electromagnetic radiation exchange between the non-contact temperature sensor and the object.

18. The system as recited in claim 15, wherein when the distance measured is not within the threshold distance, the control circuitry is configured to direct the non-contact temperature sensor to perform a measurement and is configured to direct a user interface to display a potential inaccuracy of the measurement of the non-contact temperature sensor.

19. The system as recited in claim 18, wherein the inaccuracy is due to a limitation of the field of view of the non-contact temperature sensor.