Keystone-Correcting Flex Lens


Keystone-Correcting Flex Lens


Manufacturing License Available

      For multi-screen projection where projected images must be aligned without keystoning, the projectors cannot be toed in but rather the lenses must be shifted laterally or vertically.  Keystone prevention is particularly important when projecting 3-D images with side-by-side dual video projectors.  The projectors must be kept parallel, and the lenses shifted closer together to slide the rectangular images across the screen until they register.  

Keystone-Correcting Flex Lens-01-540p   Keystone-Correcting Flex Lens-02-wobble-265w


      Previous keystone-correcting lenses were large and heavy with complicated vertical and horizontal translation mechanisms.  

     This describes a projection lens that allows the image to be shifted vertically and horizontally using three equal-length spring-steel legs, which maintain parallelism between the inner and outer barrels.  The back ends of the three legs are rigidly attached to the outter barrel, and the front ends are rigidly attached to the movable inner barrel.  Thumb screws thread through the top and side of the outer barrel to push the inner barrel vertically and horizontally. 

     The inner lens barrel can be held against the adjustment screws with a leaf spring trapped between the inner and outer barrels, or a coiled tension spring looped around the inner barrel, or by pre-loading the three legs with a spring force.


Hines' lab notebook #1 entry:

p. 83


      This is a technology announcement and license offer.  This is not a product being offered for sale.  HinesLab seeks a licensee for the Keystone-Correcting Flex Lens.  Interested manufacturers, please contact Steve Hines at:


HinesLab, Inc.
Glendale, California, USA
ph. 818-507-5812