In-line inspection of ophthalmic device with auto-alignment system and interferometer

An in-line apparatus for measuring a physical characteristic of an ophthalmic device that is a contact lens mold or a lens, the apparatus comprising:

• a vibration insensitive interferometer that is configured to determine physical dimensions of a constant supply of the ophthalmic device;
• an automatic alignment system comprising a camera, a positioner, and a controller employing control loop feedback, the system being effective to position the interferometer;
• and
• a central processing unit (CPU) in communication with the automatic alignment system and receiving measurements from the interferometer,
• wherein a front curve radius, a back curve radius, and/or a power of the ophthalmic device are determined in real time.

A method of measuring a physical characteristic of an ophthalmic device in-line comprising:

• continuously supplying the ophthalmic device;
• obtaining a vibration insensitive interferometer that sends measurements to a central processing unit (CPU);
• positioning the interferometer or ophthalmic device with an automatic alignment system that is in communication with the CPU;
• and
• determining in real time physical dimensions of the ophthalmic device.

An in-line system for measuring a physical characteristic of an ophthalmic device, the system comprising:

• a camera that is configured to image an actual position of a feature of the ophthalmic device;
• a vibration resistant interferometer that is configured to project a surface measurement beam having a wavelength that transmits through a beam splitter onto the ophthalmic device, the vibration resistant interferometer being configured to send measurements to a central processing unit (CPU);
• and
• an automatic alignment system that is effective to position the interferometer and the camera, the automatic alignment system being in communication with the CPU,
• wherein an optimal X, Y position of the ophthalmic device is determined by moving the camera to an expected position of the ophthalmic device and calculating an offset as a difference between the expected position and the actual position,
• wherein a laser measurement device is configured to move in a Z-direction to focus the surface measurement beam at the calculated X, Y position and determine a Z position for the feature of the ophthalmic device, and
• wherein the measurements of the ophthalmic device are completed by moving the vibration resistant interferometer and/or ophthalmic device based on the determined X, Y, Z position in relation to the ophthalmic device.

A method of measuring a physical characteristic of an ophthalmic device in-line comprising:

• determining an X, Y position in relation to the ophthalmic device by moving a camera to an expected position of the ophthalmic device, imaging an actual position of the ophthalmic device, calculating an offset as a difference between the expected position and the actual position, and applying the offset to the expected position;
• positioning a vibration insensitive interferometer to the X, Y position in relation to the ophthalmic device using an automatic alignment system, the automatic alignment system comprising a positioner;
• projecting a surface measurement beam onto the ophthalmic device, the surface measurement beam having a wavelength that transmits through a beam splitter;
• determining a Z position in relation to the ophthalmic device by moving a laser measurement device to the ophthalmic device at the calculated X, Y position in a direction of the surface measurement beam and focusing the surface measurement beam on the determined X, Y position of the ophthalmic device;
• and
• completing the measurements of the ophthalmic device by moving the vibration resistant interferometer and/or ophthalmic device based on the determined X, Y, Z position.