Lens blank alignment and blocking device and method

A method of positioning a lens blank for blocking comprising the steps of:

• providing a screen having a first side and a second side;
• providing a stage;
• placing a lens blank on the stage, said lens blank having a first surface facing the stage and reference markings on said first surface;
• generating alignment markings on the screen viewable from the first side of the screen;
• projecting a non-inverted image of the reference markings on the first side of the lens blank onto the second side of the screen;
• and
• moving the lens blank with respect to the stage while directly viewing the real image of the lens blank and the generated alignment markings until image of the reference markings on the lens blank projected on the screen are aligned with the generated alignment markings on the screen.

A method of positioning a lens blank for blocking comprising the steps of:

• providing a screen having a first side and a second side;
• providing a stage;
• placing a lens blank on the stage;
• generating alignment markings on the screen viewable from the first side of the screen;
• projecting an enlarged image of the lens blank onto the second side of the screen;
• and
• moving the lens blank with respect to the stage while viewing the enlarged image of the lens blank and the generated alignment markings until selected portions of the enlarged image of the lens blank projected on the screen are aligned with the generated alignment markings on the screen.