Abstract: A low-cost wide-angle lens assembly being comprised of a decreased number of lenses yet capable of properly correcting optical aberrations. The second lens in each lens group from the minimum to the maximum horizontal viewing angle is commonly used, and the first lens in each lens group from a reference angle to the maximum horizontal viewing angle is commonly used, thus reducing the total number of required lenses. Aberrations are favorably corrected by satisfying predetermined conditions as to focal distances and back focuses of the lenses.

Abstract: A laser processing apparatus includes a laser beam source, a focusing optical system for focusing a laser beam from the source as a processing laser beam to a surface of an article, an illuminating optical system using a laser beam of the same frequency as that of the processing laser beam as an illumination laser beam for illuminating the surface of the article, and a photographing device for detecting the illumination laser beam reflected from the article through the focusing optical system to thereby monitor a position to be processed. Since the laser beam of the illuminating optical system is of the same frequency as that of the processing beam chromatic aberration is prevented. This allows increased monitoring accuracy so that an article such as copper foil can be processed by a laser beam with an accuracy of 10 microns to monitor and correct a processing position.

Abstract: Emitted light of a light emitting device (3) placed interiorly of a transparent cylindrical member (1) is reflected by a flat mirror (8) formed on an end of the transparent cylindrical member (1), then the reflected light is focused on a bar code (41) to be detected by an elliptical mirror (11) formed on the side (11A) of the cylindrical member (1), and reflected light from the bar code (41) is converged on a light receiving device (2) disposed interiorly of the cylindrical member (1) by a convex lens (9) which is formed on the other end of the transparent cylindrical member (1).

Abstract: An optical pattern detecting apparatus has a ball lens (2), a light emitting device such as LED (3) and a light receptor such as photodiode (4), the latter two (3, 4) being disposed side-by-side with their optical axis substantially in parallel so that light from the light emitting device (3) passes is converged by the ball lens (2) onto barcode mark (7) and light reflected from said barcode mark (7) is guided by the same ball lens (2) to the light receptor (4); and by use of the ball lens, the apparatus can stably detect the barcode mark even at inclination of the apparatus to the surface of the barcode mark.