Abstract: A four-piece infrared single wavelength projection lens system in accordance with the present invention comprises, in order from an image side to an image source side: a stop; a first lens element with a positive refractive power having an image-side surface being convex near an optical axis, the first lens element is made of glass material; a second lens element with a refractive power having an image-side surface being convex near the optical axis and an image source-side surface being concave near the optical axis; a third lens element with a negative refractive power having an image-side surface being concave near the optical axis and an image source-side surface being concave near the optical axis; and a fourth lens element with a positive refractive power having an image-side surface being concave near the optical axis and an image source-side surface being convex near the optical axis.

Abstract: A two-piece infrared single wavelength projection lens system includes, in order from an image side to an image source side: a first lens element with a positive refractive power having an image-side surface being convex near an optical axis and an image source-side surface being concave near the optical axis, at least one of the image-side and the image source-side surfaces of the first lens element being aspheric; a second lens element with a positive refractive power having an image-side surface being concave near the optical axis and an image source-side surface being convex near the optical axis, at least one of the image-side and the image source-side surfaces of the second lens element being aspheric; and a stop disposed before the image source-side surface of the first lens element or between the image source-side surface of the first lens element and an image-side surface of the second lens element.

Abstract: A six-piece optical lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a negative refractive power, a third lens element with a positive refractive power, a fourth lens element with a negative refractive power, a fifth lens element with a positive refractive power, and a sixth lens element with a negative refractive power. Such arrangements can provide a miniaturized six-piece optical lens system having a big stop and high image quality.

Abstract: A three-piece infrared single wavelength projection lens system includes, in order from an image side to an image source side: a first lens element with a positive refractive power; a second lens element with a negative refractive power; a third lens element with a positive refractive power; and a stop disposed before an image source-side surface of the first lens element or between an image-side surface of the first lens element and an image source-side surface of the second lens element. Such arrangements can provide a three-piece infrared single wavelength projection lens system with better image sensing function.

Abstract: A three-piece infrared single wavelength projection lens system includes, in order from an image side to an image source side: a first lens element with a positive refractive power; a second lens element with a refractive power; a third lens element with a positive refractive power; a stop disposed before an image source-side surface of the first lens element or between the image source-side surface of the first lens element and an image source-side surface of the second lens element; and the first lens element or the second lens element is made of glass. Such arrangements can provide a three-piece infrared single wavelength projection lens system with better image sensing function.

Abstract: A four-piece infrared single wavelength lens system includes, in order from the object side to the image side: a first lens element with a positive refractive power, a stop, a second lens element with a refractive power, a third lens element with a positive refractive power, and a fourth lens element with a negative refractive power. The focal length of the first lens element is f1, the focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: 0.05<f1/f23<1.8. When the above relation is satisfied, a wide field of view can be obtained and the resolution can be improved evidently.

Abstract: A four-piece infrared single wavelength lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power. Such arrangements can provide a four-piece infrared single wavelength lens system which has a wide field of view, high resolution, short length and less distortion.

Abstract: A four-piece infrared single wavelength lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power. Such arrangements can provide a four-piece infrared single wavelength lens system which has a wide field of view, high resolution, short length and less distortion.

Abstract: A two-piece infrared single wavelength projection lens system includes, in order from an image side to an image source side: a first lens element with a refractive power having an image-side surface being convex near an optical axis and an image source-side surface being concave near the optical axis, at least one of the image-side surface and the image source-side surface of the first lens element being aspheric; a stop; a second lens element with a positive refractive power having an image-side surface being convex near the optical axis and an image source-side surface being concave near the optical axis, at least one of the image-side surface and the image source-side surface of the second lens element being aspheric. Such arrangements can provide a two-piece infrared single wavelength projection lens system with better image sensing function.

Abstract: A five-piece optical lens system with a wide field of view includes, in order from the object side to the image side: a first lens element with a negative refractive power, a stop, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, a fifth lens element with a negative refractive power. Such arrangements can provide a five-piece optical lens system which has a wide field of view, high resolution, short length and less distortion.

Abstract: A five-piece optical lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a negative refractive power, a third lens element with a negative refractive power, a fourth lens element with a negative refractive power, a fifth lens element with a positive refractive power. Such arrangements not only can be applied to a portable electronic product, but also has a long focal length, high pixel and low height.

Abstract: A five-piece optical imaging lens, in order from an object side to an image side, includes: an aperture stop; a first lens element with a positive refractive power having an object-side surface being convex near an optical axis and the image-side surface being concave near the optical axis; a second lens element with a negative refractive power having an object-side surface being convex near the optical axis and an image-side surface being concave near the optical axis; a third lens element with a negative refractive power having an image-side surface being concave near the optical axis; a fourth lens element with a positive refractive power having an object-side surface being concave near the optical axis and an image-side surface being convex near the optical axis; a fifth lens element with a negative refractive power having an image-side surface being concave near the optical axis.

Abstract: A three-piece infrared single wavelength lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a positive refractive power, and a third lens element with a positive refractive power. The focal length of the first lens element is f1, the focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: 0.5<f1/f23<1.0. When the above relation is satisfied, a wide field of view can be obtained and the resolution can be improved evidently.

Abstract: A six-piece microscope lens system includes, in order from the object side to the image side: a first lens element with a positive refractive power, a stop, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, a fifth lens element with a positive refractive power, a sixth lens element with a negative refractive power. Such arrangements can reduce the volume so as to reduce the manufacturing cost, has high pixel and image magnification 4.5×, and can detect biological fluid.

Abstract: A six-piece microscope lens system includes, in order from the object side to the image side: a first lens element with a positive refractive power, a stop, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, a fifth lens element with a positive refractive power, a sixth lens element with a negative refractive power. Such arrangements can reduce the volume so as to reduce the manufacturing cost, has high pixel and image magnification 4.5×, and can detect biological fluid.

Abstract: A six-piece optical lens system includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a negative refractive power, a third lens element with a positive refractive power, a fourth lens element with a negative refractive power, a fifth lens element with a positive refractive power, and a sixth lens element with a negative refractive power. Such arrangements can provide a miniaturized six-piece optical lens system having a big stop and high image quality.

Abstract: A five-piece optical imaging lens, in order from an object side to an image side, includes: an aperture stop; a first lens element with a positive refractive power having an object-side surface being convex near an optical axis and the image-side surface being concave near the optical axis; a second lens element with a negative refractive power having an object-side surface being convex near the optical axis and an image-side surface being concave near the optical axis; a third lens element with a negative refractive power having an image-side surface being concave near the optical axis; a fourth lens element with a positive refractive power having an object-side surface being concave near the optical axis and an image-side surface being convex near the optical axis; a fifth lens element with a negative refractive power having an image-side surface being concave near the optical axis.

Abstract: A six-piece optical lens system with a wide field of view includes, in order from the object side to the image side: a first lens element with a negative refractive power, a second lens element with a positive refractive power, a stop, a third lens element with a positive refractive power, a fourth lens element with a negative refractive power, a fifth lens element with a positive refractive power, a sixth lens element with a negative refractive power. Abbe numbers of the third, fourth, fifth, sixth lens elements are V3, V4, V5, V6, a focal length of the six-piece optical lens system with a wide field of view is f, a distance from an object-side surface of the first lens element to an image plane along an optical axis is TL, satisfying the relations: 29<V3?V4<42; 29<V5?V6<42; 0.1<f/TL<0.4.

Abstract: An optical lens system with a wide field of view includes, in order from the object side to the image side: a stop, a first lens element with a negative refractive power, a second lens element with a positive refractive power, a third lens element with a negative refractive power, a fourth lens element with a positive refractive power, and a fifth lens element with a negative refractive power. Such arrangements can provide a five-piece optical lens system which has a wide field of view, high resolution, short length and less distortion.

Abstract: An optical lens system with a wide field of view includes, in order from the object side to the image side: a stop, a first lens element with a positive refractive power, a second lens element with a negative refractive power, a third lens element with a positive refractive power, and a fourth lens element with a negative refractive power. The focal length of the first lens element is f1, the focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation: 0.4<f1/f23<1.7. When the above relation is satisfied, a wide field of view can be obtained and the resolution can be improved evidently.