Proximity sensor and proximity sensing method using light quantity of reflection light

• US 9,243,904 B2
• Filed: 07/12/2013
• Issued: 01/26/2016
• Est. Priority Date: 07/18/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Jun Haeng, Ryu, Hyun Surk, Lee, Kyoobin, Delbruck, Tobi, Berner, Raphael
• Primary Examiner(s): Ratcliffe, Luke
• Assistant Examiner(s): Woldemaryam, Assres H
• Application Number:
  US13/940,349
• Publication Number:
  US 20140022528A1
• Time in Patent Office: 928 Days
• Field of Search: 356 301- 316, 356 401- 41, 702/159
• US Class Current: 1/1
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01C 3/02 Details
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: H03K 17/941 using an optical detector H03K17/968 takes precedence
• CPC Class Codes: H03K 2217/94108 making use of reflection
• CPC Class Codes: H03K 2217/94116 increasing reliability, fail-safe

Abstract

A proximity sensor and proximity sensing method using a change in light quantity of a reflected light are disclosed. The proximity sensor may include a quantity change detection unit which detects a change in a quantity of reflected light which is output light which has been reflected by an object, where an intensity of the output light changes, and a proximity determination unit which determines a proximity of the object to the quantity change detection unit based on a change in the intensity of the output light and the detected change in the quantity of the reflected light.

Claims

1. A proximity sensor comprising:

a light source which varies an intensity of output light over time;

a quantity change detection unit which measures an increase or decrease in a quantity of light incident to pixels, and outputs a number of on events or off events respectively based on the increase or decrease in the quantity of the light incident to the pixels, each of the number of on events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is increased and each of the number of off events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is decreased; and

a proximity determination unit which uses an occurrence number of the on events or the off events to determine a proximity of an object,

wherein the output light is reflected by the object and is incident to the pixels.

2. The proximity sensor of claim 1, wherein the on events or the off events correspond to the change detected in the quantity of the light incident to the pixels during a predetermined time measured from a time when the change in intensity of the output light occurs.

3. The proximity sensor of claim 1, wherein the proximity determination unit determines the proximity of the object further based on a temporal distribution pattern of the on events or the off events.

4. The proximity sensor of claim 1, wherein the proximity determination unit determines the proximity of the object using a difference between a time when the number of the on events or the off events is maximized and a time when the change in the intensity of the output light occurs.

5. The proximity sensor of claim 1, wherein the quantity change detection unit detects a change in a quantity of environmental light incident on the pixels when the light source does not output the output light, wherein the on events or the off events correspond to the change in the quantity of the environmental light incident on the pixels,

wherein an intensity of the environmental light varies over time according to a motion of the object, and

wherein the environmental light is different from the output light from the light source and the incident light corresponding to the output light.

6. The proximity sensor of claim 5, further comprising a motion recognition unit which recognizes the motion of the object using the change in the quantity of the environmental light related to the motion of the object.

7. The proximity sensor of claim 6, wherein the motion recognition unit recognizes the motion of the object using the number of the on events or the oft events.

8. The proximity sensor of claim 6, wherein the motion recognition unit recognizes the motion of the object using an interval of the on events or the off events.

9. The proximity sensor of claim 6, wherein the motion recognition unit recognizes the motion of the object using an occurrence direction of the on events or the off events.

10. The proximity sensor of claim 6, wherein the motion recognition unit recognizes the motion of the object using a type of the on events or the off events, each of the on events or off events corresponding to a change in the quantity of the environmental light incident to a pixel in an image including the object related to the motion of the object.

22. The proximity sensor of claim 1, wherein the proximity determination unit determines the proximity of the object using a relationship between the time when the light source changes the intensity of the output light and a time when the on events or the off events are detected.

23. The proximity sensor of claim 22, wherein the proximity determination unit determines the proximity of the object by measuring a difference between the time when the light source changes the intensity of the output light and a time when the number of the on events or the off events is at a maximum during a predetermined time after the change in the intensity of the output light occurs.

24. The proximity sensor of claim 6, wherein the motion recognition unit determines when the on events or off events exceed a reference value, counts an excess number based on a number of the on events or the off events that exceed the reference value and determines the the motion of the object using the excess number.

11. A proximity sensing method comprising:

varying an intensity of output light over time;

measuring an increase or decrease in a quantity of light incident to pixels;

determining an occurrence number corresponding to a number of on events or off events respectively based on the increase or decrease in the quantity of the light incident to the pixels, each of the number of on events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is increased and each of the number of off events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is decreased; and

determining a proximity of an object using the occurrence number of the on events or the off events,

wherein the output light is reflected by the object and is incident to the pixels.

12. The proximity sensing method of claim 11, wherein the on events or the off events correspond to the change detected in the quantity of the light incident to the pixels during a predetermined time measured from a time when the change in intensity of the output light occurs.

13. The proximity sensing method of claim 11, wherein the determining comprises determining the proximity of the object further based on a temporal distribution pattern of the on events or the off events.

14. The proximity sensing method of claim 11, wherein the determining comprises determining the proximity of the object using a difference between a time when the number of the on events or the off events is maximized and a time when the change in the intensity of the output light occurs.

15. The proximity sensing method of claim 11, further comprising detecting a change in a quantity of environmental light incident on the pixels when a light source does not output the output light, wherein the on events or the off events correspond to the change in the quantity of the environmental light incident on the pixels,

wherein an intensity of the environmental light varies over time according to a motion of the object, and

wherein the environmental light is different from the output light from the light source and the incident light corresponding to the output light.

16. The proximity sensing method of claim 15, further comprising recognizing the motion of the object using the change in the quantity of the environmental light related to the motion of the object.

17. The proximity sensing method of claim 16, wherein the recognizing comprises recognizing the motion of the object using the number of the on events or the off events.

18. The proximity sensing method of claim 16, wherein the recognizing comprises recognizing the motion of the object using an interval of the on events or the off events.

19. The proximity sensing method of claim 16, wherein the recognizing comprises recognizing the motion of the object using an occurrence direction of the on events or the off events.

20. The proximity sensing method of claim 16, wherein the recognizing comprises recognizing the motion of the object using a type of the on events or the off events.

21. A non-transitory computer readable recording medium storing a program to cause a computer to execute a method comprising:

varying an intensity of output light over time;

receiving a number of on events or off events respectively based on an increase or decrease in a quantity of light incident to pixels;

each of the number of on events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is increased and each of the number of off events corresponding to a respective pixel among the pixels at which the quantity of light incident to the respective pixel is decreased;

determining an occurrence number corresponding to the number of the on events or the off events; and

determining a proximity of an object using the occurrence number of on the events or the off events,

wherein the output light is reflected by the object and is incident to the pixels.