Abstract: A binocular includes an eye-piece tube, a first lens system associated with the eye-piece tube for providing a base magnification as seen through the eye-piece tube, and an eye-piece module having a second lens system therein which is interchangeably installed in the eye piece tube for changing the position of the first lens system to a position of a preset increase in magnification.

Abstract: An optical scanning system is provided which includes a light source, a scanning deflector which deflects a bundle of rays emitted from the light source, and a scanning lens system which converges the deflected bundle of rays onto an image surface to form an image. The scanning lens system has at least two lenses, wherein the lens closest to the image surface is a meniscus lens with a surface which is convex in the main scanning direction facing the image surface. A surface of the meniscus lens nearest to the scanning deflector is a deformed toric surface which is convex in a sub scanning direction facing the scanning deflector. The sub scanning direction is normal to the main scanning direction. The convexed toric surface has a radius of curvature which is determined independently of a radius of curvature in the main scanning direction.

Abstract: An optical scanning system is provided which includes a light source, a scanning deflector which deflects a bundle of rays emitted from the light source, and a scanning lens group which converges the deflected bundle of rays onto an image surface to form an image. The scanning lens group includes at least one glass lens and at least two plastic lenses, and the at least one glass lens provides substantially all the power of the scanning lens group.

Abstract: The improved optical deflector including a rotating shaft that is supported freely rotatable around the body of a motor, as well as an optical deflecting element and a magnet that are both fitted around the rotating shaft is further provided with a turbulence forming member in the neighborhood of the rotating element which is composed of the rotating shaft, the optical deflecting element and the magnet. The air stream generated by the rotation of the optical deflecting element is transformed to turbulences so as to block the development of a "negative" pressure in the space between a stator coil base (fixed member) and the magnet (rotating member). Therefore, the grease can be prevented from splashing in the optical deflector that uses ball bearings; in the case where the optical deflector is of a type that uses a dynamic pressure spindle, the galling of the spindle can be prevented.

Abstract: The present invention provides a light deflector which effectively cools a rotation torque generation portion, which leads to miniaturization of the apparatus and economy of electric power.

Abstract: Apparatus and methods for stabilizing a line of sight of an optical system without the use of gimbals. The apparatus includes a fixed plano-concave lens element mounted in a frame and a moveable plano-convex lens element mounted in a carriage. The frame mounts onto a preexisting optical system such that the lens elements are nominally aligned with the line of sight of the preexisting optical system. A motor driving unit is provided in the frame which moves the plano-convex lens element back and forth relative to the fixed plano-concave lens element about two orthogonal movement axes in response to small amplitude disturbances imparted to the optical system. The line of sight stabilization apparatus is suitable for retrofit installation onto preexisting optical systems, and in particular, to missile tracking guidance and sighting systems which were originally manufactured or installed without line of sight stabilization capability.

Abstract: A lens centering apparatus of a lens barrel having therein a lens supporting frame includes male threads provided on an outer periphery of the lens supporting frame, and female thread sets provided on the lens barrel and having different centers. The female thread sets can be selectively engaged by the male threads of the lens supporting frame.

Abstract: The present invention is a scanning system and a novel method for compensating for the variations in the output power of the beam from an A-O cell. The novel method involves varying the amount of drive current through the laser diode in such a fashion as to compensate for the loss of power due to diffraction inefficiencies. The amount of driving current is dependent upon the amount of power desired in the output beam from the A-O cell. The system and method of the present invention sets the output power from the A-O cell to a desired value. As the diffraction efficiency increases at other portions of the scan, the drive current is cut appropriately to compensate for the increased efficiency; thus keeping the output spot power at the desired value. Likewise, as the diffraction efficiency decreases at other portions of the scan, the drive current should be increased to compensate for the decrease in efficiency; thereby maintaining the desired value.

Abstract: The present invention provides a CFRP-made optical cylinder comprising, as the main CFRP layers, (a) CFRP layers containing a carbon fiber arranged in a direction substantially parallel to the cylinder axial direction and (b) CFRP layers containing a carbon fiber arranged in a direction making an angle of substantially.+-.(40.about.50) degree to the cylinder axial direction, in which cylinder at least 50% by weight of the carbon fiber arranged in a direction substantially parallel to the cylinder axial direction has a linear expansion coefficient of -1.times.10.sup.-6 /.degree.C. or less and at least 50% by weight of the carbon fiber arranged in a direction making all angle of substantially.+-.(40.about.50) degree to the cylinder axial direction has a linear expansion coefficient of -1.times.10.sup.-6 /.degree.C. or less, and which cylinder has a linear expansion coefficient of -0.5.times.10.sup.-6 /.degree.C. to 0.5.times.10.sup.-6 /.degree.C. in the axial direction.