| 摘要 |
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. |
