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;
wherein the output can be used to estimate the proximity of the object.
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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.
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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; wherein the output can be used to estimate the proximity of the object. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9)
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5. The method of 1, wherein step (d) includes:
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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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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