Abstract: In an image recorder, a recording photobeam and a reference photobeam are periodically deflected by a polygon mirror in a main scanning direction. The recording photobeam is supplied to a photosensitive film while the reference beam is supplied to a transparent grating scale on which a transparent area and an opaque area are formed. The combination boundary of the transparent area and the opaque area has a portion parallel to the main scanning direction. The reference beam transmitted through the transparent area is detected, and the photobeams are deflected in a subscanning direction by an acoustic-optical deflector in response to the detected optical amount of the reference photobeam.

Abstract: An optical lighting system comprising either an optical system or an optical mirror system. In the optical lens and optical mirror systems, the light incident and exiting planes of the lenses and mirrors, are formed to satisfy given equations. Accordingly, in a contact or proximity exposure system, it is possible to unify irradiance on a surface to be irradiated and reduce the optical path length, thus reducing the overall device size. In a projection system, it is possible to unify irradiance on an image surface while efficiently utilizing light by ommitting a gradient filter.

Abstract: An illumination system applicable to contact or proximity exposure apparatuses provides excellently collimated light without any irradiance reduction in the peripheral area of an object to be illuminated and includes a light source, an ellipsoidal mirror positioned with respect to the light source, an optical system designed so that the entrance height of the light received in the entrance pupil thereof is substantially proportioned to the tangent of the exit angle in the exit pupil thereof, and a single Fresnel lens designed so that light passing therethrough is abated in the spherical aberration. Light exiting from the optical system is received on the front surface of the Fresnel lens, where the irradiance distribution is uniform through the surface, and the Fresnel lens transmits light received with abated spherical aberration to a mask film bearing a desired circuit pattern.

Abstract: Disclosed is a novel optical system for illuminating an object which provides an increased irradiance in the peripheral area of the object. The optical system includes a light source, an entrance pupil for receiving light from the light source, an exit pupil for passing the light received to the object, and an optical axis which extends through the optical system to the light source and the object, respectively, wherein the relationship among the incident height h to the entrance pupil, an illumination height H on the object, and a changing rate (dh/dH) of the incident height and the illumination height is defined by a function, f(H)=(h/H)(dh/dH). The optical system is designed so as to satisfy the following formula in the peripheral area of the object: f(0)<f(H). The function f(0) is represented by f(0)=[fa'/(a'-f)b'}].sup.2, where a' is a distance between the light source and the primary principal point of the optical system, and b' is a distance between the real image of the light source and the object.

Abstract: An optical system, useful for a flying-spot scanning apparatus includes a laser tube, an acousto-optical modulator, a deflecting mirror directing the laser beam in a first direction, and an objective lens having the characteristic of h=f.multidot.sin .theta., where h is the distance on an object between the optical axis and the point upon which the laser beam impinges, f is the focal length of the objective lens and .theta. is the angle formed by the beam entering the objective lens with respect to the optical axis. The objective lens includes a first optical unit having the negative focal length and a second optical unit having a positive focal length. The third-order distortion coefficient of the objective lens is approximately "1". Straight and parallel scanning loci can be effected on a recording medium, as the recording medium is fed in a second direction.

Abstract: An optical system for use in a flying spot scanning apparatus. The optical system includes a laser tube, an optoelectronic integrated circuit which divides a laser beam into a plurality of beams and individually modulates the beams, a focusing lens for focusing the beams, a deflection mirror for reciprocatingly deflecting the beams to scan a recording medium, a concave mirror receiving the beams thereon, and a recording medium disposed optically behind the concave mirror. The recording medium is fed in a predetermined direction while the beams are scanned across the recording medium.

Abstract: A method of measuring the orientation of the constituents of specimens is disclosed, which includes the steps of preparing a cavity resonator in the form of a pair of waveguides forming a cavity, said waveguides being formed with a slit, inserting a specimen sheet or web in said slit, oscillating said cavity resonator by microwaves of fixed frequency while producing a relative rotation between said inserted specimen sheet or web and the plane of microwaves of the cavity resonator, measuring the amount of attenuation of the output signal or transmitted microwave intensity from said cavity resonator with respect to said exciting input signal, and measuring the orientation from the relation between said amount of attenuation or transmitted microwave intensity and the angle of said specimen sheet with respect to the cavity resonator, said method being characterized in that the oscillation frequency of said microwaves is set shifted slightly toward the higher side from the resonance frequency of the cavity resonat