The eye-tracking system is based on the reflection of four light emitting diodes (LED)s at the cornea of user's eve. The LEDs emit infrared light at 900 nanometers and the virtual images formed behind the cornea as well as a near infrared image of the pupil are displayed on a charged couple device (CCD) sensor. The optical system used to display virtual environments is also used to conjugate the virtual images of the LEDs to the CCD sensor. This optimizes the integration of eyetracking system into the head mounted device (HMD). The four LEDs are laid out around the imaging (optical) system and their beam (rays) impinge directly on the eye by reflection on the hot mirror. Then the light reflected by the cornea is reflected again by the hot mirror, goes through the optical system and the cold mirror to be imaged on the sensor. The whole eye is illuminated by near infrared light and the contrast between the dark pupil and the bright iris on the CCD sensor allows knowledge of the location of the center of the entrance pupil. The processing of the location of the cornea images and the center of the entrance pupil leads to determine the sight direction.
This invention relates to head mounted optical eye tracking apparatus, and in particular to a method and apparatus for the display of a virtual image to a user's eyes while tracking at least one of the user's eyes to detect its sight direction and this Patent Application claims the priority of U.S. Provisional Application 60/116040 filed Jan. 14. 1999.
A wide-field-of-view projection display comprises a circularly symmetric lens and an array of light emitters, positioned along the focal circumference of the circularly symmetric lens so that light from each of the light emitters is substantially collimated by the lens in a different direction. A ray-diverting means, such as a slab waveguide or a reflector, ejects the collimated light out of the plane of the lens to the viewer. The planar circularly symmetric lens has no aberration, allowing adjacent views to be seamlessly joined because they can all be diffused by the same angular amount.
A method for determining registration accuracy of an augmented reality system is provided. The method includes the steps of providing an input device for inputting a position of a user's touch; registering the input device with a workspace coordinate system of the augmented reality system; displaying a virtual object in a known position; recording a user's touch position in response to the user attempting to touch the virtual object; and calculating a registration error of the augmented reality system by comparing the user's touch position to the known position of the virtual object. The input device may be a passive device used in conjunction with a tracking system of the augmented reality system or an active device, such as a touch-sensitive device, coupled to the augmented reality system which outputs the user's touch position.
A system for eye tracking that determines the line of sight of a user according to the relative position between the center of the pupil and a reference point, the system including an image detector that captures an image of the eye, a pupil-illuminating light source that illuminates the pupil of the user, a reference light source that illuminates a different portion of the face of the user as a reference point and an imaging processor that analyzes the captured eye image to determine the line of sight.
An imaging system illuminates body tissue with infrared light to enhance visibility of subcutaneous blood vessels, and generates a video image of the body tissue and the subcutaneous blood vessels based on reflected infrared light. The system includes an infrared light source for generating the infrared light and a structure for diffusing the infrared light. The diffusing structure includes one or more layers of diffusing material for diffusing the light. The system further includes a video imaging device for receiving the infrared light reflected from the body tissue and for generating a video image of the body tissue based on the reflected infrared light.
The present invention includes a method of fabricating an optically-pumped disk-array solid-state laser amplifier having one or more disks, wherein one or more of the one or more disks having two opposed surfaces, including the steps of patterning a photoresist mask on one or more of the two opposed surfaces of the one or more disks and processing the one or more disks through the patterned photoresist mask, whereby the temperature profile improved radially across the disk's surface, amplified spontaneous emission are reduced, or combinations thereof.
