Abstract: An ultra-short focus projection lens is configured to receive an image beam from an image source side and project the image beam toward a projection surface. The ultra-short focus projection lens has an optical axis. The ultra-short focus projection lens includes a reflective optical element, a first lens group, a stop, and a second lens group arranged in sequence along the optical axis. The image beam from the image source side passes through the second lens group, the stop, and the first lens group in sequence, and is reflected by the reflective optical element and projected to the projection surface. The first lens group includes a plurality of lenses having diopters. The second lens group 10 includes a plurality of lenses having diopters. The first lens group and the second lens group include ten lenses having diopters in total. A projection device is also provided.

Abstract: A projection lens includes a first lens group, an aperture stop, a second lens group, a reflective optical element, and a refractive optical element arranged in sequence on a transmission path of an image beam. The first lens group, the aperture stop and the second lens group are sequentially arranged from a minified side to a magnified side along an optical axis. The reflective optical element and the refractive optical element are located on opposite sides of the optical axis. The image beam sequentially passes through the first lens group, the aperture stop and the second lens group from the minified side to be transmitted to the reflective optical element. The image beam is reflected by the reflective optical element to the refractive optical element, and passes through the refractive optical element to form a projection beam toward the magnified side.

Abstract: A projection lens including a first lens group, an aperture stop, a second lens group, and a reflective optical element sequentially arranged from a reduction side to a magnification side along an optical axis is provided. The first lens group has positive refractive power. The second lens group has negative refractive power. The reflective optical element has positive refractive power. The projection lens satisfies 1.2<|F2/F1|<3.5, wherein F2 is an effective focal length of the reflective optical element, and F1 is an effective focal length of the first lens group and the second lens group. A projection apparatus is also provided.

Abstract: A projection lens structure mainly includes a first group of lenses with a negative dioptric value, a second group of lenses with a positive dioptric value, a third group of lenses with a positive dioptric value and a fourth group of lenses with a negative dioptric value. The first group of lenses further includes at least a first lens and a second lens, of which the first lens ha a plastic aspheric lens in a meniscus shape with a focal length between ?25˜?80 mm. The second group of lenses further includes at least a third lens. The third group of lenses further includes at least a first doublet with a focal length between 25˜80 mm. The fourth group of length further includes at least a group of doublets, a fourth lens and a fifth lens.

Abstract: A projection lens structure mainly includes a first group of lenses with a negative dioptric value, a second group of lenses with a positive dioptric value, a third group of lenses with a positive dioptric value and a fourth group of lenses with a negative dioptric value. The first group of lenses further includes at least a first lens and a second lens, of which the first lens ha a plastic aspheric lens in a meniscus shape with a focal length between ?25˜?80 mm. The second group of lenses further includes at least a third lens. The third group of lenses further includes at least a first doublet with a focal length between 25˜80 mm. The fourth group of length further includes at least a group of doublets, a fourth lens and a fifth lens.

Abstract: A projection lens structure includes a first group of lens, an aperture stop and a second group of lend. The aperture stop is arranged at a rear of the first group of lens to form a long-focus lens with a focal length between 30-80 mm and the second group of lens is arranged at a rear of the aperture stop to form a short-focus lens with a focal length between 20-30 mm. With the long-focus lens and the short-focus lens operated correspondingly, the structure of the projection lens is simple and the manufacturing cost is low without affecting the quality of produced images.

Abstract: A projection lens structure includes a first group of lens, an aperture stop and a second group of lend. The aperture stop is arranged at a rear of the first group of lens to form a long-focus lens with a focal length between 30-80 mm and the second group of lens is arranged at a rear of the aperture stop to form a short-focus lens with a focal length between 20-30 mm. With the long-focus lens and the short-focus lens operated correspondingly, the structure of the projection lens is simple and the manufacturing cost is low without affecting the quality of produced images.