39results about How to "Shortened back focus" patented technology

An optical imaging lens assembly includes, in order from the object side to the image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has a convex object-side surface in a paraxial region. The fourth lens element with negative refractive power has a concave object-side surface in a paraxial region. The fifth lens element with positive refractive power has a convex image-side surface in a paraxial region. The sixth lens element with negative refractive power has a concave object-side surface in a paraxial region, a concave image-side surface in a paraxial region and at least one convex shape in the off-axial region of the image-side surface of the sixth lens element. The fifth lens element and the sixth lens element are aspheric lens elements.

The invention discloses an optical image system, an image capturing device and an electronic device. The optical image system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial region thereof. The second lens element has an image-side surface being concave in a paraxial region thereof. The third lens element has negative refractive power. The fifth lens element with negative refractive power has an object-side surface and an image-side surface being both aspheric. The sixth lens element has an object-side surface and an image-side surface being both aspheric.

A photographing optical lens assembly includes, in order from object side to image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element with positive refractive power has object-side surface being convex in a paraxial region thereof. The second lens element has positive refractive power. The third and fourth lens elements have refractive power. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region thereof. An object-side surface and the image-side surface of the fifth lens element are aspheric. The sixth lens element with refractive power has an image-side surface being concave in a paraxial region thereof. When specific conditions are satisfied, it is easier to miniaturize the photographing optical lens assembly and achieve better image quality in a limited space.

A digital light processing projection system includes an illuminating device, an optical-path-switching element, a projection device and a prism set. The prism set is arranged between the illuminating device, the optical-path-switching element and the projection device and has a plurality of prisms in which an air gap existing between any two adjacent prisms. According to the invention, a light beam output from the illuminating device directly passes through the prisms and air gaps before being received by the optical-path-switching element. Under a first state, a light beam reflected from the optical-path-switching element is totally reflected at an interface between one of the prisms and one of the air gaps before being received by the projection lens. Under a second state, a light beam reflected from the optical-path-switching element is totally internal reflected back and forth within a prism being adjacent to the optical-path-switching element and is absorbed by a light absorbing material.

This invention provides an image capturing lens system comprising: a positive first lens element having a convex object-side surface; a negative second lens element having a concave object-side surface and a convex image-side surface; a third lens element with refractive power; a positive fourth lens element having a convex image-side surface, both of the object-side and image-side surfaces being aspheric; a fifth lens element with refractive power having a concave image-side surface, both of the object-side and image-side surfaces being aspheric, at least one inflection point is positioned on the image-side surface thereof. When some particular relations are satisfied, the light-focusing spots of various wavelengths can be favorably adjusted for extending the depth of field; therefore, the present image capturing lens system shall be suitable for compact electronic products with Extended Depth of Field (EDOF) function.

The invention provides an optical image capturing lens for a bar code reader, comprising a first lens of meniscus shape, with its convex surface on the object side and with the object side optical surface and the image side optical surface being aspherical surfaces, a second lens of meniscus shape, with its convex surface on the image side and with the object side optical surface and the image side optical surface being aspherical surfaces, and an image sensor. The image sensor is disposed on an imaging surface after combination of the first lens and the second lens and satisfies the relationship that 2 omega is greater than 62.0 degree and is less than 89.5 degree and TL / D1 / 2 is greater than 1.50 and less THAN 2.20, wherein the 2 omega represents diagonal angle of FOV, TL represents the distance from the object side optical surface of the first lens to the imaging surface, and D1 / 2 is a half of the length of a diagonal line of an effective sensing region of the image sensor. The optical image capturing lens for the bar code reader has shorter length, greater FOV, and excellent aberration correction capability.