Abstract: A projection screen includes a reflection layer, a light absorbing structure, a plurality of light diffusion layers, and a lens structure. The light absorbing structure is disposed on the reflection layer and has a plurality of apertures. A part of the reflection layer is exposed via the apertures. The light diffusion layers have a first index of refraction. Each of the light diffusion layer is disposed in the corresponding aperture and contacts the corresponding reflection layer exposed via the corresponding aperture. The lens structure is disposed on the light diffusion layers and the light absorbing structure. A light incidence side of the lens structure includes a plurality of convex lenses. The convex lenses are respectively corresponding with the light diffusion layers. The lens structure has a second index of refraction, and the second index of refraction is smaller than the first index of refraction.

Abstract: A touch display apparatus including a light guide plate, a light emitting module, a display panel, a plurality of prism structures, an image transmission unit, and an image detector is provided. The light guide plate has a first surface, a second surface opposite to the first surface, and a light incident surface connecting the first surface and the second surface. The light emitting module includes at least one visible light source and at least one invisible light source. The prism structures are disposed between the first surface and the display panel. The image transmission unit includes a wedge portion and a light guide portion. The wedge portion is disposed between the prism structures and the display panel. The image detector is disposed beside the light guide portion for receiving the invisible light beam from the light guide portion. A backlight module is also provided.

Abstract: A light guide unit includes a light transmissive base, a plurality of scattering particles, and a plurality of reflective particles. The light transmissive base includes a scattering region and a reflective region. The scattering region has a light emitting surface, a boundary surface, and a light incident surface. The reflective region includes a lamp cover portion and a bottom portion. The lamp cover portion is disposed beside the light incident surface. The bottom portion is disposed at one side of the boundary surface and connected with the scattering region through the boundary surface. The light transmissive base is integrally formed. The scattering particles are doped in the scattering region, and the reflective particles are doped in the reflective region. The number density of the scattering particles in the scattering region is less than that of the reflective particles in the reflective region. A backlight module is also provided.

Abstract: A light condensing film includes a reflective unit, a light-transmissive substrate, a plurality of lenses, and a plurality of refractive units. The reflective unit has a plurality of holes passing through the reflective unit, wherein the holes are distributed at the reflective unit. The light-transmissive substrate is disposed on the reflective unit. The lenses are disposed on the light-transmissive substrate. Moreover, the lenses respectively cover the holes of the reflective unit, and the light-transmissive substrate is disposed between the reflective unit and each of the lenses. The refractive units are disposed on the light-transmissive substrate and distributed among the lenses. The light-transmissive substrate is disposed between the reflective unit and each of the refractive units. Each of the refractive units has a light refraction plane surface. A backlight module and a liquid crystal display are also provided.

Abstract: An optical film has a light incident side and a light emitting side above the light incident side. V shape protrusions disposed side by side are disposed at the light incident side. Collimating units disposed side by side are disposed at the light emitting side. Each of the V shape protrusions and each of the collimating units extend along a predetermined direction. The collimating units are respectively corresponded to the V shape protrusions. Two inclined surfaces of each of the V shape protrusions are respectively a light incident surface and a reflection surface. In each corresponding pair of the V shape protrusion and the collimating unit, a central axis of the collimating unit parallel to the predetermined direction is right above the reflection surface of the V shape protrusion. A backlight module using the optical film is provided to provide a plane light source having high luminance.

Abstract: A brightness enhancement film (BEF) includes a light transmissive substrate having a first surface and a second surface, a plurality of lenses disposed on the first surface, and a reflective layer. Each of the lenses has a curved protruding surface facing away from the light transmissive substrate. The radius of curvature of the curved protruding surface in a first direction parallel to the first surface is R1, the radius in a second direction is R2, and R1?R2. The reflective layer is disposed on the second surface and has a plurality of light pass openings respectively located on the optical axes of the lenses. The distance between the apex of the curved protruding surface and the corresponding light pass opening is L, the refractive index of the lenses is n, and the BEF satisfies L<nR1/(n?1) and L<nR2/(n?1). A backing light module using the BEF is provided.

Abstract: A light emitting diode package includes a substrate, a plurality of light emitting diode chips, a fluorescence layer, and a plurality of reflecting layers. The light emitting diode chips, the fluorescence layer, and the reflecting layers are disposed on the substrate. The fluorescence layer covers the light emitting diode chips, and the reflecting layers are disposed right above the light emitting diode chips, respectively.

Abstract: A color wheel includes a fixing base, a ring filter, a washer, and a fixing ring. The fixing base has a protrusion portion and a supporting portion. The ring filter is fit on the protrusion portion. An inner margin of the ring filter leans on the supporting portion. The washer is connected to the protrusion portion. The ring filter is disposed between the washer and the supporting portion. The washer and the supporting portion clip the inner margin of the ring filter. The fixing ring has an annular supporting portion, a side wall surrounding the annular supporting portion, and fixing blocks connected to the side wall and dotted on an outer margin of the ring filter. The outer margin of the ring filter leans on the annular supporting portion. The fixing blocks, the side wall, and the annular supporting portion clip the outer margin of the ring filter.

Abstract: A projection screen includes a reflection layer, a light absorbing structure, a plurality of light diffusion layers, and a lens structure. The light absorbing structure is disposed on the reflection layer and has a plurality of apertures. A part of the reflection layer is exposed via the apertures. The light diffusion layers have a first index of refraction. Each of the light diffusion layer is disposed in the corresponding aperture and contacts the corresponding reflection layer exposed via the corresponding aperture. The lens structure is disposed on the light diffusion layers and the light absorbing structure. A light incidence side of the lens structure includes a plurality of convex lenses. The convex lenses are respectively corresponding with the light diffusion layers. The lens structure has a second index of refraction, and the second index of refraction is smaller than the first index of refraction.

Abstract: An optical film has a light incident side and a light emitting side above the light incident side. V shape protrusions disposed side by side are disposed at the light incident side. Collimating units disposed side by side are disposed at the light emitting side. Each of the V shape protrusions and each of the collimating units extend along a predetermined direction. The collimating units are respectively corresponded to the V shape protrusions. Two inclined surfaces of each of the V shape protrusions are respectively a light incident surface and a reflection surface. In each corresponding pair of the V shape protrusion and the collimating unit, a central axis of the collimating unit parallel to the predetermined direction is right above the reflection surface of the V shape protrusion. A backlight module using the optical film is provided to provide a plane light source having high luminance.

Abstract: A zoom lens suitable for imaging an object on a photosensitive device is provided. The zoom lens includes a first lens group, a second lens group, a third lens group and a fourth lens group, which are arranged in series. The fourth lens group is disposed near the photosensitive device. The second lens group and the third lens group are suitable for moving between the first lens group and the fourth lens group. The first lens group, the second lens group, the third lens group and the fourth lens group include at least a glass lens and a plurality of plastic lenses. The number of the plastic lenses is more than the number of glass lenses. Thus, overall cost of producing the zoom lens is lower.

Abstract: A zoom lens including a first lens group with a negative refractive power and a second lens group with a positive refractive power is provided. The first lens group includes a first lens, a second lens, and a third lens arranged from an object side to an image side in sequence. The refractive powers of the first, second, and third lenses are negative, negative, and positive sequentially. The second lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged from the object side to the image side in sequence. The refractive powers of the fourth, fifth, sixth, and seventh lenses are positive, positive, negative, and positive sequentially. The first lens group and the second lens group are capable of moving between the object side and the image side.

Abstract: A backlight module including at least one light emitting element and a brightness enhancement diffuser is provided. The light emitting element is capable of emitting a light beam. The brightness enhancement diffuser is disposed in the transmission path of the light beam and has a first surface and a second surface opposite to the first surface. The light beam passes through the first surface and the second surface. The brightness enhancement diffuser includes a plurality of protrusions and a plurality of recesses. The protrusions are disposed on the first surface, and each of the protrusions has a curved surface. The recesses are disposed on the first surface, and each of the recesses has at least one plane surface. Each of the recesses is surrounded by several of the protrusions.

Abstract: An illumination system capable of providing at least one light beam to a light valve is provided. The illumination system includes at least one light source, a linearization beam shaper and an optical scanning device. The light source is capable of providing the light beam. The linearization beam shaper is disposed on a transmission path of the light beam and between the light source and the light valve to expand the light beam along a first direction. The optical scanning device is disposed on the transmission path of the light beam and between the linearization beam shaper and the light valve. The optical scanning device is capable of moving for making the light beam scan on the light valve unidirectionally along a second direction or back and forth along the second direction.

Abstract: A zoom lens including a first lens group with a negative refractive power and a second lens group with a positive refractive power is provided. The first lens group includes a first lens, a second lens, and a third lens arranged from an object side to an image side in sequence. The refractive powers of the first, second, and third lenses are negative, negative, and positive sequentially. The second lens group includes a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged from the object side to the image side in sequence. The refractive powers of the fourth, fifth, sixth, and seventh lenses are positive, positive, negative, and positive sequentially. The first lens group and the second lens group are capable of moving between the object side and the image side.

Abstract: An optical engine including a beam splitting and combining system, which includes a first polarizing beam splitting (PBS) unit, a dichroic unit and a second PBS unit, is provided. A first color beam is reflected by the first PBS unit, is reflected by a first light valve, and passes through the first PBS unit sequentially. A second color beam passes through the first PBS unit, is reflected by a second light valve, and is reflected by the first PBS unit sequentially. The dichroic unit is disposed on an optical path of the first and second color beams. The second PBS unit is capable of allowing a third color beam to travel to a third light valve and allowing the third color beam reflected from the third light valve to travel to the dichroic unit. The dichroic unit is capable of combining the first, second and third color beams.

Abstract: A zoom lens suitable for imaging an object on a photosensitive element is provided. The zoom lens includes a first lens group, a second lens group disposed between the first lens group and the photosensitive element, a third lens group disposed between the second lens group and the photosensitive element, and a fourth lens group. The second lens group is suitable for moving between the first lens group and the third lens group. The third lens group includes two lenses having positive refractive power. The fourth lens group is disposed and suitable for moving between the third lens group and the photosensitive element. The refractive powers of the first lens group, the second lens group, the third lens group, and the fourth lens group are a positive value, a negative value, a positive value, and a positive value respectively.

Abstract: A fixed-focus lens including a first lens group, a second lens group, and a third lens group is provided. The first lens group has a negative refractive power, includes a plurality of lenses, and is disposed between an object side and an image side. The lenses of the first lens group include at least one aspheric lens. The second lens group is disposed between the first lens group and the image side and has a positive refractive power. The third lens group is disposed between the second lens group and the image side and has a positive refractive power. The third lens group includes a first triple cemented lens and a second triple cemented lens arranged from the object side to the image side in sequence.

Abstract: A color wheel includes a fixing base, a ring filter, a washer, and a fixing ring. The fixing base has a protrusion portion and a supporting portion. The ring filter is fit on the protrusion portion. An inner margin of the ring filter leans on the supporting portion. The washer is connected to the protrusion portion. The ring filter is disposed between the washer and the supporting portion. The washer and the supporting portion clip the inner margin of the ring filter. The fixing ring has an annular supporting portion, a side wall surrounding the annular supporting portion, and fixing blocks connected to the side wall and dotted on an outer margin of the ring filter. The outer margin of the ring filter leans on the annular supporting portion. The fixing blocks, the side wall, and the annular supporting portion clip the outer margin of the ring filter.

Abstract: A color wheel includes a motor having a rotary shaft, and a filter set sleeved on the rotary shaft. The filter set including a filter plate having a central axis and upper and lower surfaces, and a first and a second packing disposed concentrically and respectively on the upper and lower surfaces of the filter plate. The first packing has a first notch formed therein. The second packing has a second notch formed in an upper surface thereof. An adhering unit is provided in the first and second notches to fix respectively the first and second packing to the upper and lower surfaces of the filter plate.