Abstract: A projection screen for diffusing illumination light into a range of viewing angles is formed by depositing a coating on a substrate. Within the coating are particles having an average particle height. Protrusions at least two microns higher than the average particle height may be substantially uniformly distributed over the screen. In some embodiments, each protrusion may be no closer than 80 microns to another protrusion.

Abstract: A projection screen for diffusing illumination light into a range of viewing angles is formed by depositing a coating on a substrate. Within the coating are particles having an average particle height. Protrusions at least two microns higher than the average particle height may be substantially uniformly distributed over the screen. In some embodiments, each protrusion may be no closer than 80 microns to another protrusion.

Abstract: A virtual input element image projection apparatus couples a suitable lens and an optical element to increase the diverging angle of a virtual input element image or generate a plurality of portions of the virtual input element image that are coupled to form the complete virtual input element image without reducing diffraction efficiency. The projection distance for generating the virtual input element image may also be shortened.

Abstract: A light guide plate, for use with a back-light module for seasonal scanning in dividing zones, includes a light-pervious substrate having a plurality of dividing blocks formed thereon, an optical grating structure disposed on light incident surface of each of the dividing blocks for allowing light to enter, and a light diffusion structure disposed on an optical surface of each of the dividing blocks for diffusing the light. As the light-pervious substrate is adapted for seasonal scanning in different zones, the provision of the optical grating structure can shorten the light mixing distance while the light diffusion structure can evenly emit and spread the light throughout the light guide plate to solve the drawbacks of the prior techniques. Further, a back-light module having the light guide plate is provided.

Abstract: Direct backlight modules using diffraction optical elements are provided. A direct backlight module includes a light source and a diffraction optical element, wherein the diffraction optical element is disposed above the light source. By properly arranging the phase function, the diffraction optical element can substantially modulate the wavefront of the light emitted from the light source and control light distribution as well as light direction.

Abstract: A brightness enhancement film includes a substrate, a plurality of curved prism units and a plurality of light scattering particles. The curved prism units are extended in parallel and formed on a first surface of the substrate. Each of the curved prism units includes at least one meandering surface to provide with changes in curvature. Thus, the meandering surface of the curved prism unit is able to refract incident light in two dimensions with respect to the substrate that may enhance entire light-collecting efficiency in two dimensions. The light scattering particles are disposed in the curved prism units.

Abstract: A zoom lens formed in a small size adaptable to a thin and portable device, having three lens groups, including, from the object plane to the image forming plane: a first lens group with a negative power, a second lens group with a positive power and a third lens group with a positive power. By controlling the ratio of the focal length of the second lens group and the focal length of the tele-photo end, image distortion may be controlled, and the total length of the lens may be reduced to shrink the size of the lens. Hence production costs may be reduced, which is important to mass production.

Abstract: A brightness enhancement film includes a substrate, a plurality of curved prism units and a light-diffusing microstructure layer. The curved prism units are extended in parallel and formed on a first surface of the substrate. Each of the curved prism units includes at least one meandering surface to provide with changes in curvature. Thus, the meandering surface of the curved prism unit is able to refract incident light in two dimensions with respect to the substrate that may enhance entire light-collecting efficiency in two dimensions. The light-diffusing microstructure layer is formed on a second surface of the substrate.

Abstract: An anti-counterfeit method and system by using a nano metal grating, wherein an object to be recognized is formed with the nano metal grating. During the recognition process, an incidental light is applied on the metal grating. In response to the incidental light, the metal grating has its specific optical incidence and reflection characteristics. The object is then identified whether it is genuine or fake by observing the refraction light passing through and reflection light reflected from the metal grating. Further, the incident light beam can be polarized to generate polarized light beams and then irradiated on the metal grating, whereafter the recognition of the object is performed by observing the reflection and refraction lights of the irradiated polarized light beam. The recognition further can be accomplished by rotating the metal grating, thus the intensity of the refraction and reflection lights will accordingly be changed, thereby identifying the object.

Abstract: Direct backlight modules using diffraction optical elements are provided. A direct backlight module includes a light source and a diffraction optical element, wherein the diffraction optical element is disposed above the light source. By properly arranging the phase function, the diffraction optical element can substantially modulate the wavefront of the light emitted from the light source and control light distribution as well as light direction.

Abstract: A zoom lens formed in a small size adaptable to a thin and portable device, having three lens groups, including, from the object plane to the image forming plane: a first lens group with a negative power, a second lens group with a positive power and a third lens group with a positive power. By controlling the ratio of the focal length of the second lens group and the focal length of the tele-photo end, image distortion may be controlled, and the total length of the lens may be reduced to shrink the size of the lens. Hence production costs may be reduced, which is important to mass production.

Abstract: An anti-counterfeit method and system by using a nano metal grating, wherein an object to be recognized is formed with the nano metal grating. During the recognition process, an incidental light is applied on the metal grating. In response to the incidental light, the metal grating has its specific optical incidence and reflection characteristics. The object is then identified whether it is genuine or fake by observing the refraction light passing through and reflection light reflected from the metal grating. Further, the incident light beam can be polarized to generate polarized light beams and then irradiated on the metal grating, whereafter the recognition of the object is performed by observing the reflection and refraction lights of the irradiated polarized light beam. The recognition further can be accomplished by rotating the metal grating, thus the intensity of the refraction and reflection lights will accordingly be changed, thereby identifying the object.

Abstract: A virtual input element image projection apparatus couples a suitable lens and an optical element to increase the diverging angle of a virtual input element image or generate a plurality of portions of the virtual input element image that are coupled to form the complete virtual input element image without reducing diffraction efficiency. The projection distance for generating the virtual input element image may also be shortened.

Abstract: A grating interference device with adjustable resolution has high stability and precision adjustment functions. The invention has two reflectors and a beam splitter. One of the reflector is installed on a rotating axis along with an optic fiber or a platform of planar waveguide. Through the rotating axis, this reflector and the platform are maintained at a fixed relative angle and rotate with respect to the other reflector and the beam splitter. The period of the interference grating is controlled by the angle change, producing a grating with a micrometer-order period on the optic fiber or the planar waveguide.

Abstract: This specification discloses a planar optical waveguide DWDM (Dense Wavelength Division Multiplexer), which is an integrated DWDM made by using the planar optical waveguide manufacturing technology. A diffractive grating is used in a planar optical path to direct beams of different wavelengths in a beam into different directions. An arrayed waveguide installed at the output end of the planar optical path couples the beams of different wavelengths to an optical fiber connected at the output end, separating the waves. On the other hand, a preferred embodiment of the invention has an arrayed lens between the diffractive grating and the arrayed waveguide. The arrayed lens can correct the deviated diffractive beams due to thermal deformation of the diffractive grating and conduct them into the arrayed waveguide.

Abstract: A grating interference device with adjustable resolution has high stability and precision adjustment functions. The invention has two reflectors and a beam splitter. One of the reflector is installed on a rotating axis along with an optic fiber or a platform of planar waveguide. Through the rotating axis, this reflector and the platform are maintained at a fixed relative angle and rotate with respect to the other reflector and the beam splitter. The period of the interference grating is controlled by the angle change, producing a grating with a micrometer-order period on the optic fiber or the planar waveguide.

Abstract: This specification discloses a planar optical waveguide DWDM (Dense Wavelength Division Multiplexer), which is an integrated DWDM made by using the planar optical waveguide manufacturing technology. A diffractive grating is used in a planar optical path to direct beams of different wavelengths in a beam into different directions. An arrayed waveguide installed at the output end of the planar optical path couples the beams of different wavelengths to an optical fiber connected at the output end, separating the waves. On the other hand, a preferred embodiment of the invention has an arrayed lens between the diffractive grating and the arrayed waveguide. The arrayed lens can correct the deviated diffractive beams due to thermal deformation of the diffractive grating and conduct them into the arrayed waveguide.