Optical film
Assignee3M Innovative Properties Company
InventorsDale L. Ehnes, Mark E. Gardiner, Alan B. Campbell
Life of this patent
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Abstract
Optical films having anti-Moiré and anti-wetout features are described, along with systems and methods for making these optical films. A master used to make optical films is formed using a single axis actuator cutting along a trajectory that is out of plane with the surface of the master. Movement of the cutting tool along the trajectory cuts grooves having variable depth and variable pitch into the surface. Prisms formed from the master have variable depth, variable height prisms that provide anti-wetout and anti-Moiré features.
Claims53
A system for modifying a surface to produce a master for making optical films, the system comprising:
- a cutting tool;
- a drive mechanism configured to provide relative motion between the cutting tool and the surface;
- and
- a single axis actuator coupled to move the cutting tool along a trajectory that is out-of-plane with the surface, the trajectory having a non-zero x-component, perpendicular to the surface, and a non-zero z-component, parallel to the surface, wherein movement of the cutting tool along the trajectory during the relative motion between the cutting tool and the surface is configured to cut grooves having variable depth and variable pitch into the surface.
A method of modifying a surface to produce a master for making optical films, the method comprising:
- moving a cutting tool across the surface;
- and
- as the cutting tool moves across the surface, also moving the cutting tool back and forth along a trajectory that has a non-zero x component, perpendicular to the surface, and a non-zero z-component, parallel to the surface, to cut grooves having variable pitch and variable depth into the surface.
A master for making optical films, comprising:
- a surface;
- and
- grooves in the surface, the grooves having varying pitch and varying depth, wherein the variation in pitch is dependent on the variation in depth.
An optical film, comprising prisms, each of the prisms having variation in pitch and variation in height, wherein the variation in pitch is dependent on the variation in height.
An optical film, comprising:
- a substantially flat surface;
- and
- a second surface comprising a first group of prisms interleaved with a second group of prisms, each prism of the first group having a prism peak that lies in a plane substantially parallel to the flat surface and having variation in pitch, each prism of the second group having relatively greater height than the prisms of the first group.
A system for modifying a surface to produce a master for making optical films, the system comprising:
- a cutting tool;
- a machine drive mechanism configured to provide relative motion between the cutting tool and the surface, the machine drive mechanism also configured to move the cutting tool perpendicular to the surface to cut grooves in the surface having a low frequency variation in depth of about 0.5 microns to about 50 microns;
- and
- an actuator configured to move the cutting tool parallel to the surface to cut high frequency pitch variation in the grooves, the high frequency pitch variation having a range of about 0.5 microns to about 50 microns and a wavelength of about 5 microns to about 500 microns.
A method of modifying a surface to form a master for making the optical films, comprising:
- moving a cutting tool to cut grooves in the surface, the grooves having a low frequency variation in depth in range of about 0.5 microns to about 50 microns;
- and
- moving the cutting tool to cut a high frequency pitch variation in the grooves, the high frequency variation in pitch having a range of 0.5 microns to 50 microns with a wavelength of about 5 microns to about 500 microns.
A master for making an optical film, comprising:
- a surface;
- and
- grooves in the surface, each groove having a variation in pitch and a variation in depth, where the variation in pitch has a higher frequency than the variation in depth.
An optical film, comprising:
- a substantially flat surface;
- and
- a second surface comprising an array of prisms, each prism of a first group of the prisms having a prism peak that lies in a plane substantially parallel to the flat surface and having a variation in pitch and each prism of a second group of the prisms having a variation in height.
Dependencies are inferred from the claim text.