Abstract: A photolithography projection lens, having a plurality of lens elements and a light diaphragm arranged among them, arranged along an optical axis, and comprising an object side and an image side respectively arranged at the front and rear ends of the plurality of lens elements; wherein: the diopters of the two lenses respectively near the object side and the image side must be positive; each of the lens elements is a single lens without cement; the angle between the chief rays at different image height positions and the optical axis is <1 degree, and the angle between the chief rays at different object height positions and the optical axis is <1 degree; and under the projection of 350˜450 nm wavelength light, it provide the imaging effect of precise magnification.

Abstract: A method of scanning a tag for tracking a cloth by Point of Sale (POS) device during the selling process and the method comprises following steps of: 1) scanning a cloth tag that is attached to cloth for identifying the cloth and transmitting a cloth-identification signal indicating a location of the cloth; 2) renting the cloth to a customer with an option to buy followed by tracking the location of the cloth by receiving the cloth-identification signal from the cloth tag; and 3) managing the availability of the cloth when the customer returns the cloth after a prearranged rental period.