Proximity sensors and methods for sensing proximity
First Claim
1. A method for use in monitoring the proximity of an object, comprising:
- (a) controlling a light source;
(b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object;
(c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and
(d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto so that an affect of the ambient light on the output is substantially removed;
wherein because the affect of the ambient light on the output is substantially removed, the output produced at step (d) can be used to produce one or more estimate of the proximity of the object that is/are substantially unaffected by the ambient light.
3 Assignments
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Accused Products
Abstract
In an embodiment, a proximity sensor includes a driver, a photo-diode (PD) and an analog-to-digital converter (ADC). The proximity sensor can also include a controller to control the driver. The driver selectively drives a light source, e.g., an infrared (IR) light emitting diode (LED). The PD, which produces a current signal indicative of the intensity of light detected by the PD, is capable of detecting both ambient light and light produced by the light source that is reflected off an object. The ADC receives one or more portion of the current signal produced by the PD. The ADC produces one or more digital output that can be used to estimate the proximity of an object to the PD in a manner that compensates for ambient light detected by the PD and transient changes to the detected ambient light.
26 Citations
25 Claims
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1. A method for use in monitoring the proximity of an object, comprising:
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(a) controlling a light source; (b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object; (c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and (d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto so that an affect of the ambient light on the output is substantially removed; wherein because the affect of the ambient light on the output is substantially removed, the output produced at step (d) can be used to produce one or more estimate of the proximity of the object that is/are substantially unaffected by the ambient light. - View Dependent Claims (2, 3, 4)
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5. A method for use in monitoring the proximity of an object, comprising:
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(a) controlling a light source; (b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object; (c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and (d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto; wherein the output can be used to estimate the proximity of the object; wherein step (d) comprises producing the output by subtracting one or more value indicative of the intensity detected at step (c) from one or more value indicative of the intensity detected at step (b). - View Dependent Claims (6)
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7. A method for use in monitoring the proximity of an object, comprising:
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(a) controlling a light source; (b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object; (c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and (d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto; wherein the output produced at step (d) can be used to estimate the proximity of the object; and wherein step (d) includes; increasing a count value of an up-down counter or an accumulator based on the intensity detected at step (b); and decreasing a count value of the up-down counter or the accumulator based on the intensity detected at step (c); wherein the output produced at step (d) is an output of the up-down counter or the accumulator.
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8. A method for use in monitoring the proximity of an object, comprising:
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(a) controlling a light source; (b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object; (c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and (d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto; wherein the output produced at step (d) can be used to estimate the proximity of the object; and wherein step (d) includes using a dual-input single output analog to digital converter (ADC) to produce the output that can be used to estimate the proximity of the object.
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9. A method for use in monitoring the proximity of an object, comprising:
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(a) controlling a light source; (b) during one or more time period, detecting an intensity of both ambient light and light produced by the light source that is reflected off the object; (c) during one or more further time period while the light source is not producing light, detecting the intensity of the ambient light; and (d) producing, based on the intensities detected at steps (b) and (c), an output indicative of the intensity of the detected light produced by the light source that is reflected off the object, and that compensates for the ambient light including transient changes thereto; wherein step (a) comprises selectively driving an infrared light emitting diode (IR LED); and wherein step (b) comprises detecting light at a photo-diode (PD); wherein during the one or more time period of step (b), the intensity of the light detected by the PD is indicative of both ambient light and IR light produced by an IR LED that is reflected off the object; wherein during the one or more further time period of step (c), the intensity of the light detected by the PD is indicative of the intensity of the ambient light; and wherein the output produced at step (d) can be used to estimate the proximity of the object.
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10. A proximity sensor, comprising:
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a driver to selectively drive a light source; a photo-diode (PD) that produces a current signal indicative of the intensity of light detected by the PD, the PD capable of detecting ambient light and detecting light produced by the light source that is reflected off an object; and an analog-to-digital converter (ADC) that receives one or more portion of the current signal produced by the PD; wherein the ADC produces one or more digital output that can be used to estimate the proximity of an object to the PD in a manner that compensates for the ambient light detected by the PD and transient changes to the detected ambient light. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A proximity sensor, comprising:
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a driver to selectively drive a light source; a photo-diode (PD) that produces a current signal indicative of an intensity of light detected by the PD; an analog-to-digital converter (ADC) that includes a first input, a second input and an output; a controller to control the driver and to control switches that direct portions of the current signal produced by the PD to either the first input or the second input of the ADC; wherein the ADC includes up-down counter that selectively counts up or down, based on the portions of the current signal provided to the first and second inputs, to thereby produce a count value that is indicative of light produced by the light source that is reflected off an object and detected by the PD; and wherein the count value, which is provided at the output of the ADC, can be used to estimate the proximity of an object to the PD.
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25. A system, comprising:
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a driver to selectively drive a light source; a photo-diode (PD) that produces a current signal indicative of the intensity of light detected by the PD, the PD capable of detecting ambient light and detecting light produced by the light source that is reflected off an object; and an analog-to-digital converter (ADC) that receives one or more portion of the current signal produced by the PD; wherein the ADC produces one or more digital output indicative of the proximity of an object to the PD in a manner that compensates for the ambient light detected by the PD and transient changes to the detected ambient light; a comparator or processor that receives the one or more digital output and enables or disables a subsystem based on the one or more digital signal indicative of the proximity of the object to the PD.
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Specification