To realize automatic zooming of presbyopia glasses, we proposed a gaze distance detection method based on binocular tracking. A theoretical model was built to calculate gaze distance based on the gaze directions of two eyeballs. The gaze direction of each eyeball was obtained by the pupil center corneal reflection method. Three light-emitting diodes (LEDs) and two miniature cameras were placed on the glasses frame around the eyeball. Then, gaze direction was derived by calculating the distances between the pupil center and the positions of three LED reflection images by the corneal from the images captured by cameras. The experiment setup was built to test the gaze direction and gaze distance. The experimental result demonstrates that it is an effective way to obtain the user’s gaze distance for automatically adjusting the focal length of the zoom glasses.
A compact optical zoom camera module with Alvarez freeform elements is reported. A 3 × magnification in the optical zoom system was achieved by means of lateral shifting two pairs of Alvarez lenses. The optical design performances, profiles of the freeform surfaces, tolerance analysis results, and Monte Carlo yield simulation for mass production of the optical zoom system are presented. The optomechanical structures of the whole camera module including the barrels, actuators, and the slide-guiding systems are also described. The Alvarez elements and aspheric lenses were fabricated by precise injection molding and the movable elements are actuated by voice coil motors with a stroke of 3 mm. A camera module was developed with a size of 25 mm (width) × 25 mm (length) × 6 mm (height). The zooming and imaging capabilities of this Alvarez zoom lens were demonstrated experimentally.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.