Abstract: An optical film includes a plurality of alternating first and second polymeric layers disposed on a first protective layer. Each of the first and second polymeric layers has an average thickness less than about 500 nm and the first protective layer has an average thickness greater than about 750 nm. An olefin layer can be disposed on the first protective layer opposite the plurality of alternating first and second polymeric layers. The olefin layer includes cyclic olefin copolymer, cyclic olefin polymer, or a blend thereof. The olefin layer can have an unstructured major surface opposite the first protective layer. A bonding layer is disposed between, and bonds together, the olefin layer and the first protective layer. The optical film is integrally formed.

Abstract: An optical assembly includes an integral lens assembly having one or more lenses bonded to each other with spaced apart major first and second lens surfaces. First and second optical films are bonded to respective major first and second lens surfaces. The first and second optical films includes a plurality of polymeric layers. Each of the polymeric layers have an average thickness of less than about 500 nm. For a substantially normally incident light and a visible wavelength range the plurality of polymeric layers in the first optical film has an average optical transmittance and an average optical reflectance of greater than about 70% for a first polarization state and an orthogonal second polarization state, respectively. The plurality of polymeric layers in the second optical film has an average optical transmittance of greater than about 70% for at least one of the first and second polarization states.

Abstract: An optical film includes a first optical stack disposed on a visible light absorbing second optical stack. Each of the first and second optical stacks includes a plurality of alternating polymeric first and second layers. The first layers have a higher index of refraction than the second layers at least along an in-plane same first direction. For substantially normally incident light and for at least 80% of wavelengths in a visible wavelength range, the plurality of alternating polymeric first and second layers for at least the first optical stack reflects more than about 60% of the incident light polarized along the first direction and transmits more than about 45% of the incident light polarized along an in-plane orthogonal second direction, and at least the first layers of the second optical stack are more light absorbing for the incident light polarized along the first direction than the second direction.

Abstract: An optical assembly includes an integral lens assembly having one or more lenses bonded to each other with spaced apart major first and second lens surfaces. First and second optical films are bonded to respective major first and second lens surfaces. The first and second optical films includes a plurality of polymeric layers. Each of the polymeric layers have an average thickness of less than about 500 nm. For a substantially normally incident light and a visible wavelength range the plurality of polymeric layers in the first optical film has an average optical transmittance and an average optical reflectance of greater than about 70% for a first polarization state and an orthogonal second polarization state, respectively. The plurality of polymeric layers in the second optical film has an average optical transmittance of greater than about 70% for at least one of the first and second polarization states.

Abstract: An optical system includes a display, at least one lens, and at least one of a partial reflector and a reflective polarizer. The optical system forms a virtual image of an image emitted by the display for viewing by an eye. The emitted image includes a plurality of cones of image light. Each cone of image light propagates from a different corresponding location on the emitted image and includes a central light ray propagating along a central axis, such that in each of orthogonal first and second planes that include the central axis, an intensity distribution of the cone of image light as a function of angle relative to the central axis includes a substantially flat peak having a full width of at least 15 degrees across which the peak changes by less than about 20%, and a corresponding fullwidth at half maximum that is less than about 60 degrees.

Abstract: Various embodiments of an accessory mounting device are disclosed. The device can be adapted to engage an elongated rail. The device can include a body having top, bottom, and first and second side surfaces. Each of the side surfaces can include a rail engagement portion adjacent the bottom surface of the body and an accessory engagement portion adjacent the top surface. The device can also include a locking mechanism including a lever connected to the body at a pivot, and a tab extending from the lever in a direction away from the bottom surface. In one or more embodiments, the locking mechanism can include first and second levers each connected to the body at a pivot. The lever can rotate about a pivot axis in a direction toward the top surface of the body when the locking mechanism is manipulated from a locked position to an unlocked position.

Abstract: An accessory mounting system (30) and a helmet (10) that includes such systems are disclosed. The accessory mounting system (30) includes a plate (32) adapted to be permanently connected to a substantially continuous portion of a ballistic layer (12) of a helmet, where the ballistic layer has an outer surface (14). The plate (32) includes an inner surface (34) and an outer surface (36), where the inner surface of the plate is adapted to be disposed in contact with an outer surface of the ballistic layer. The accessory mounting system also includes an accessory rail (50) adapted to be removably connected to the plate, where the accessory rail includes an inner surface (52) and an outer surface (54). The inner surface of the accessory rail is adapted to be disposed in contact with the plate.

Abstract: Various embodiments of an accessory mounting device are disclosed. The device can be adapted to engage an elongated rail. The device can include a body having top, bottom, and first and second side surfaces. Each of the side surfaces can include a rail engagement portion adjacent the bottom surface of the body and an accessory engagement portion adjacent the top surface. The device can also include a locking mechanism including a lever connected to the body at a pivot, and a tab extending from the lever in a direction away from the bottom surface. In one or more embodiments, the locking mechanism can include first and second levers each connected to the body at a pivot. The lever can rotate about a pivot axis in a direction toward the top surface of the body when the locking mechanism is manipulated from a locked position to an unlocked position.

Abstract: A method for a light bulb or fixture to emit light and measure ambient light. The method includes driving solid state light sources, such as LEDs, in the bulb with a cyclical signal to repeatedly turn them off and on, where the light sources are turned off and on at a rate sufficient for the bulb to appear on. The method also includes measuring ambient light via a light sensor in or on the bulb during at least some times when the light sources are off, and outputting a signal related to the measured ambient light. In some cases the light sensor saturates when the solid state light sources are active and measures the ambient light level when the solid state light sources are not active. The ambient light level signal can be used to control when the light bulb is on and an intensity of light output by the bulb.

Abstract: A method for a light bulb or fixture to emit light and measure ambient light. The method includes driving solid state light sources, such as LEDs, in the bulb with a cyclical signal to repeatedly turn them off and on, where the light sources are turned off and on at a rate sufficient for the bulb to appear on. The method also includes measuring ambient light via a light sensor in or on the bulb during at least some times when the light sources are off, and outputting a signal related to the measured ambient light. In some cases the light sensor saturates when the solid state light sources are active and measures the ambient light level when the solid state light sources are not active. The ambient light level signal can be used to control when the light bulb is on and an intensity of light output by the bulb.

Abstract: A method for a light bulb or fixture to emit light and measure ambient light. The method includes driving solid state light sources, such as LEDs, in the bulb with a cyclical signal to repeatedly turn the solid state light sources off and on, where the light sources are turned off and on at a rate sufficient for the bulb to appear on. The method also includes measuring ambient light via a light sensor in or on the bulb during at least some times when the light sources are off, and outputting a signal related to the measured ambient light. The ambient light level signal can be used to control when the light bulb is on and an intensity of light output by the bulb.

Abstract: A method for a light bulb or fixture to emit light and measure ambient light. The method includes driving solid state light sources, such as LEDs, in the bulb with a cyclical signal to repeatedly turn the solid state light sources off and on, where the light sources are turned off and on at a rate sufficient for the bulb to appear on. The method also includes measuring ambient light via a light sensor in or on the bulb during at least some times when the light sources are off, and outputting a signal related to the measured ambient light. The ambient light level signal can be used to control when the light bulb is on and an intensity of light output by the bulb.