Abstract: An electronic device has an optical lens. The optical lens includes in order from an object side to an image-forming side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The second lens and the third lens have negative powers respectively, and the fourth lens, the sixth lens, and the eighth lens have positive powers respectively. The first lens is a plastic lens. The object-side surface of the first lens is a convex, surface and/or the image-side surface of the first lens is a concave surface. The sixth lens and the seventh lens are made into a doublet lens.

Abstract: An optical lens, in order from an object side to an image-forming side, includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The object-side surface of the first lens has an effective diameter ?1. The image-side surface of the first lens has a curvature radius R2 and an effective radius D2. The object-side surface of the second lens has an effective diameter ?2. The optical lens satisfies at least one of the following conditions: 0.2??2/?1, ?2/?1?0.65, 0.65?D2/R2 and D2/R2?1.2.

Abstract: An electronic device has an optical lens. The optical lens includes in order from an object side to an image-forming side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The second lens and the third lens have negative powers respectively, and the fourth lens, the sixth lens, and the eighth lens have positive powers respectively. The first lens is a plastic lens. The object-side surface of the first lens is a convex, surface and/or the image-side surface of the first lens is a concave surface. The sixth lens and the seventh lens are made into a doublet lens.

Abstract: An optical lens, in order from an object side to an image-forming side, includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The object-side surface of the first lens has an effective diameter ?1. The image-side surface of the first lens has a curvature radius R2 and an effective radius D2. The object-side surface of the second lens has an effective diameter ?2. The optical lens satisfies at least one of the following conditions: 0.2??2/?1, ?2/?1?0.65, 0.65?D2/R2 and D2/R2?1.2.

Abstract: This invention provides compact photographic and projection modules and electronic systems having the photographic and projection modules, which not only can project image data but also can capture image with good image quality high zoom ratio. Additionally, the photographic and projection modules are reliable and able to be made with low cost.

Abstract: A zoom lens primarily includes, in order from an object side to an image-forming side, a first lens group having negative refractive power; a second lens group having positive refractive power and at least consisting of a first lens and a second lens; and a third lens group having positive refractive power. The refractive index of the first lens (Nd21), the refractive index of the second lens (Nd22), the total length of the first lens group, the second lens group, and the third lens group (TTL), and the shortest focal length of the zoom lens (fw) satisfy the following conditions: Nd21?Nd22>0.1 and TTL/fw?1.3.

Abstract: This invention provides compact photographic and projection modules and electronic systems having the photographic and projection modules, which not only can project image data but also can capture image with good image quality high zoom ratio. Additionally, the photographic and projection modules are reliable and able to be made with low cost.

Abstract: A zoom lens primarily includes, in order from an object side to an image-forming side, a first lens group having negative refractive power; a second lens group having positive refractive power and at least consisting of a first lens and a second lens; and a third lens group having positive refractive power. The refractive index of the first lens (Nd21), the refractive index of the second lens (Nd22), the total length of the first lens group, the second lens group, and the third lens group (TTL), and the shortest focal length of the zoom lens (fw) satisfy the following conditions: Nd21?Nd22>0.1 and TTL/fw?1.3.

Abstract: Embodiments of the present invention disclose a lens module and its temperature-compensating method. The lens module primarily includes several lenses and a compensating lens. The several lenses comprise two plastic lenses and the ratio of the focal length of one plastic lens to the other is predetermined. The temperature-compensating method employs the compensating lens to shift alone an optical axis for compensation of the focal length departure. In one embodiment, the ratio of the two focal lengths is more than or equal to 0.5 and less than or equal to 2.

Abstract: An image-projecting and image-capturing system primarily includes a projecting sub-system for projecting an image and a capturing sub-system for capturing an image. The capturing sub-system primarily comprises a zoom lens that consists of many lens groups moving along an optical axis. When capturing an image, the projecting sub-system is arranged at a location out of the optical axis; when projecting an image, the projecting sub-system is moved to aim the optical axis.

Abstract: A structure of a light source for a projector includes a light source, a housing and a shade. The housing includes a transparent surface. The light source is disposed in the housing. The shade is disposed on the transparent surface for blocking part of light emitted from the light source.

Abstract: A color wheel of a projector includes a red segment, a green segment, a blue segment and a white segment. The white segment is coated so as to provide color temperature of 6500K or 7000K. The red, green and blue segments are coated so as to provide full-segment transmission. The area ratio of the red segment, the green segment and the blue segment on the color wheel is designed based on the color temperature of the color wheel, so that color coordinate deviations can be reduced.

Abstract: A projector and a color filtering device thereof. The color filtering device for filtering a light includes a first filter and a second filter. The first filter includes a yellow filter area, a cyan filter area and a green filter area. The second filter includes a magenta filter area. The second filter is movable with respect to the first filter, so that the magenta filter area is selectively overlapped with the yellow filter area and the cyan filter area respectively. The light passing through the overlapping magenta filter area and yellow filter area is red, while the light passing through the overlapping magenta filter area and cyan filter area is blue.