US 11,537,201 B1 · Eye tracking imager with gated detectors receiving a specular reflection

Abstract

Technologies are described herein for an eye tracking that may be employed by devices and systems such as head mount display (HMD) devices. Light that is reflected from a user's eye may be specular or scattered. The specular light has an intensity or magnitude that may saturate the electronics. The presently disclosed techniques mitigate saturation by generating detected signals from an optical detector, evaluating the signal levels for the detected signal, and selectively gating the detected signals that have saturated. The remaining scattered signals can be combined to achieve a combined signal that can be converted into a digital signal without saturating the electronics, which can then be processed to form an image of the eye for identification purposes, for tracking eye movement, and for other uses. The described technologies provide a clear image without ambient light reflections or specular light interfering with the image.

Claims20

Dependent claims

A device to detect and process light reflected from an eye of a user, the device comprising:

a first optical detector circuit that provides a first analog detection signal responsive to a first incident light reflected from the eye of the user;
a second optical detector circuit that provides a second analog detection signal responsive to a second incident light reflected from the eye of the user;
a first path selector with a first input to receive the first analog detection signal, a second input to receive the second analog detection signal, a control input to receive a first selection signal, and an output to selectively couple one of the first and second inputs to the output responsive to the first selection signal;
a second path selector with a first input to receive the second analog detection signal, a second input to receive the first analog signal, a control input to receive a second selection signal, and an output to selectively couple one of the first and second inputs to the output responsive to the second selection signal;
and
a summer with a first input that is coupled to the output of the first path selector, a second input that is coupled to the output of the second path selector, and generate a combined analog signal as a summation of the first and second inputs to the summer.

3 more elements

A device to detect and process incident light reflected from an eye of a user, the device comprising:

an array of optical detectors, each configured to provide a corresponding one of an array of analog detection signals responsive to a corresponding incident light reflected from the eye of the user;
an array of saturation detectors, each configured to receive the corresponding array of analog detection signal and generate a corresponding selection signal responsive to a comparison of the corresponding analog detection signal to a corresponding threshold;
and
a signal combiner configured to receive the plurality of selection signals and the plurality of analog detection signals, wherein the signal combiner is configured to selectively combine the plurality of analog detection signals to generate a combined analog signal based on the array of selection signals, wherein non-saturated signals are promoted over saturated signals in the combined analog signal.

1 more element

A device to generate an electrical response to light incident that light includes specular and scattered reflections from the eye of a user, the device comprising:

an optical detector that generates a plurality of electrical signals responsive to the light incident on the optical detector;
a signal combiner that receives the plurality of electrical signals from the optical detector, evaluates a signal level of each of the plurality of electrical signals to determine when the signal level of the corresponding one of the plurality of electrical signals has saturated, and selectively combines the plurality of electrical signals to generate a combined analog signal based on the determined signal levels such that non-saturated signals are promoted over saturated signals in the combined analog signal;
and
an analog-to-digital converter that receives the combined analog signal from the signal combiner, samples the combined analog signals, and generates a digital signal as a conversion of the sampled analog signal into a digital value.

1 more element

Dependencies are inferred from the claim text.

Eye tracking imager with gated detectors receiving a specular reflection

Life of this patent

Eye tracking imager with gated detectors receiving a specular reflection

Life of this patent

Abstract

Claims20