US Patent 10049272 User authentication using multiple capture techniques

Examples are disclosed herein that relate to user authentication. One example provides a biometric identification system comprising an iris illuminator, an image sensor configured to capture light reflected from irises of a user as a result of those irises being illuminated by the iris illuminator, a drive circuit configured to drive the iris illuminator in a first mode and a second mode that each cause the irises to be illuminated differently, the first and second modes thereby yielding a first mode output at the image sensor and a second mode output at the image sensor, respectively, and a processor configured to process at least one of the first mode output and the second mode output and, in response to such processing, select one of the first mode and the second mode for use in performing an iris authentication on the user.