Apparatus and Circuit with a Multi-Directional Arrangement of Optical Elements

• US 20110248152A1
• Filed: 12/21/2010
• Published: 10/13/2011
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Holcombe, Wayne T., Svajda, Miroslav
• Granted Patent: US 8,704,152 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/46 Indirect determination of position data
• CPC Class Codes: G01S 3/7803 Means for monitoring or calibrating
• CPC Class Codes: G01S 3/7835 using coding masks
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4913 Circuits for detection, sampling, integration or read-out
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers

Abstract

An apparatus includes a housing having a front surface, a rear surface, and at least one sidewall therebetween and a plurality of optical windows formed in the housing to allow light to pass through from multiple directions. The apparatus further includes a plurality of photo detectors to generate electrical signals based on received light, where each of the plurality of photo detectors is disposed within a respective one of the plurality of optical windows. The apparatus also includes a control circuit coupled to the plurality of photo detectors to receive the electrical signals, determine light variations from the electrical signals, and determine a change in position of an object based on variation ratios of the light variations received by at least one pair of photo detectors within the plurality of photo detectors in response to determining the light variations.

Claims

1. An apparatus comprising:

a housing having a front surface, a rear surface, and at least one sidewall therebetween;

a plurality of optical windows formed in the housing, each of the plurality of optical windows allowing light to pass through from multiple directions;

a plurality of photo detectors to generate electrical signals based on received light, each of the plurality of photo detectors disposed within a respective one of the plurality of optical windows; and

a control circuit coupled to the plurality of photo detectors to receive the electrical signals, determine light variations from the electrical signals, and determine a change in position of an object based on variation ratios of the light variations received by at least one pair of photo detectors within the plurality of photo detectors in response to determining the light variations.

2. The apparatus of claim 1, wherein the control circuit is configured to determine the change in position of the object relative to at least one of the front surface, the rear surface, and the at least one sidewall.

3. The apparatus of claim 1, wherein each of the plurality of optical windows comprises:

an opening defined in the housing in the at least one sidewall and along an adjacent portion of one of the front surface and the rear surface; and

a cover extending along a portion of the at least one sidewall and an adjacent portion of at least one of the front surface and the rear surface, the cover configured to seal the opening, the cover including at least one aperture defining a transparent region.

4. The apparatus of claim 1, further comprising:

a plurality of light-emitting diodes; and

a second plurality of optical windows, each of the second plurality of optical windows includes at least one of the plurality of light-emitting diodes.

5. The apparatus of claim 4, wherein the at least one sidewall includes a plurality of corner portions, each of the plurality of corner portions includes one of the second plurality of optical windows.

6. The apparatus of claim 4, where the at least one sidewall includes a plurality of corner portions, each of the plurality of corner portions includes one of the first plurality of optical windows.

7. The apparatus of claim 1, wherein each of the plurality of optical windows allows light to pass through at multiple angles, the multiple angles providing an optical range of greater than ninety degrees.

8. The apparatus of claim 1, wherein at least one of the plurality of optical windows includes an optical reflector configured to direct light in a particular direction.

9. The apparatus of claim 1, wherein the control circuit is configured to communicate the change in position of the object to a host processor to determine a user input in response to the change in position.

10. A circuit comprising:

a substrate including at least one sidewall;

a plurality of photodiodes configured to generate electrical signals based on received light including light variations caused by an object moving relative to the substrate, at least some of the plurality of photodiodes positioned along the at least one sidewall of the substrate and configured to receive light from at least two angles;

a plurality of optical barriers, at least one of the plurality of optical barriers disposed between adjacent ones of the plurality of photodiodes; and

a control circuit coupled to the plurality of photodiodes, the control circuit to receive the electrical signals, determine the light variations from the electrical signals, and determine a change in position of the object based on variation ratios of the light variations received by at least one pair of photodiodes of the plurality of photodiodes in response to determining the light variations.

11. The circuit of claim 10, further comprising:

a plurality of output terminals coupled to the control circuit and configured to couple to a plurality of light-emitting diodes; and

wherein the plurality of optical barriers include at least one optical barrier disposed between the plurality of light-emitting diodes and the at least some of the plurality of photodiodes.

12. The circuit of claim 11, further comprising a reflector adjacent to at least one photodiode from the plurality of photodiodes to expand a view angle of the at least one photodiode from the plurality of photodiodes to receive light from multiple angles.

13. The circuit of claim 11, further comprising a reflector adjacent to at least one light-emitting diode from the plurality of light-emitting diodes to expand a view angle of the at least one light-emitting diode to direct light at multiple angles.

14. The circuit of claim 10, wherein at least one of the plurality of photodiodes is positioned on the substrate at a tilt angle that is greater than zero degrees and less than ninety degrees relative to a planar surface of the substrate.

15. An apparatus comprising:

a housing including a front wall, a rear wall and at least one sidewall extending therebetween;

a plurality of optical elements;

a plurality of optical windows formed along the at least one sidewall, each optical window providing a view angle allowing light to pass through from at least two directions relative to the housing, each of the plurality of optical windows including at least one of the plurality of optical elements; and

a control circuit within the housing and coupled to the plurality of optical elements, the control circuit configured to determine light variations using at least some of the plurality of optical elements and determine a change in position of an object based on variation ratios of the light variations received by at least one pair of optical elements of the plurality of optical elements in response to determining the light variations.

16. The apparatus of claim 15, wherein the control circuit detects a user input in response to determining the change in position of the object.

17. The apparatus of claim 16, wherein the change in position of the object is determined relative to at least one of the front wall, the rear wall, and the at least one sidewall.

18. The apparatus of claim 15, wherein the plurality of optical elements comprises at least one light-emitting diode and at least one photo sensor.

19. The apparatus of claim 15, wherein the view angle comprises multiple directions from which light can be received that provides an angle of greater than ninety degrees.

20. The apparatus of claim 15, further comprising a reflective element disposed within at least one of the plurality of optical windows to expand the view angle to direct light in multiple directions.

21. The apparatus of claim 15, further comprising a plurality of optical barriers adjacent to the control circuit and configured to partially obstruct light from reaching at least some of the plurality of optical elements to provide spatial dependence between the plurality of optical elements.