Abstract: Dichroic mirrors are disposed at the same inclination angle in a position such that a plane including an incidence optical path and a reflection optical path (transmission optical path of green light) of blue light reflected at a reflecting surface of one dichroic mirror is orthogonal to a plane including an incidence optical path and a reflection optical path of red light reflected at the other dichroic mirror. The other dichroic mirror is formed by cementing two glass substrates, and a red light reflecting layer is formed on the joint surface.

Abstract: A projector optical system has an illumination optical system, a dichroic surface, and a projection lens system. The dichroic surface is inclined with respect to the illumination principal ray traveling from the beam center of the illumination light emitted from the illumination optical system to the centers of the reflection-type display panels, and also with respect to the projection principal ray traveling from the centers of the reflection-type display panels to the center of the aperture stop of the projection lens system.

Abstract: A color projection display apparatus has a white light source, splitting means, a reflective color display device and projecting means. The splitting means splits a white luminous flux from the white light source into a plurality of luminous fluxes of different wavelength ranges, and from which luminous fluxes corresponding to the wavelength ranges exit in different directions. The reflective color display device modulates and reflects the luminous fluxes corresponding to the wavelength ranges which luminous fluxes exit from the splitting means and are incident from different directions. The projecting means projects the luminous fluxes modulated by the reflective color display device as image light. The luminous fluxes modulated and reflected by the reflective color display device are incident on the projecting means after being again transmitted by the splitting means.

Abstract: A scanning-type image viewing optical system has a light source for emitting luminous flux; a main scanning means for scanning luminous flux in a first direction; a sub-scanning means for scanning luminous flux in a second direction different from the first direction; and an eyepiece lens for directing luminous flux scanned by the two scanning means to the pupil of an observer, wherein the main scanning means has a conjugate relationship with the pupil position of the observer via the eyepiece lens, and when the pupil diameter, i.e., the luminous flux diameter of the incident luminous flux at the pupil position of the observer, is designated d and the main scan diameter, i.e., the luminous flux diameter exiting the main scanning means, is designated d', the conjugate magnification .beta. calculated by d/d' satisfies the conditional equation .beta..ltoreq.0.85.

Abstract: A scanning-type image viewing optical system has a light source for emitting luminous flux; a main scanning means for scanning luminous flux in a first direction; a sub-scanning means for scanning luminous flux in a second direction different from the first direction; and an eyepiece lens for directing luminous flux scanned by the two scanning means to the pupil of an observer, wherein the main scanning means has a conjugate relationship with the pupil position of the observer via the eyepiece lens, and when the pupil diameter, i.e., the luminous flux diameter of the incident luminous flux at the pupil position of the observer, is designated d and the main scan diameter, i.e., the luminous flux diameter exiting the main scanning means, is designated d', the conjugate magnification .beta. calculated by d/d' satisfies the conditional equation 1.2.ltoreq..beta..

Abstract: A projector optical system has a reflection-type display panel, an illumination optical system for illuminating the reflection-type display panel, a projection optical system for projecting the images displayed on the reflection-type display panel onto a projected surface, and a light-deriving means for directing illumination light toward the reflection-type display panel. The projection optical system has, from the projected-surface side, a front lens unit and a rear lens unit. The light-deriving means is disposed between the front and rear lens units. Additionally, the following condition is fulfilled:-1.5<.phi.F/.phi.<-0.1where .phi.F represents the optical power of the front lens unit of the projection optical system, and .phi. represents the optical power of the entire projection optical system.

Abstract: An apparatus has a member to be driven, an actuator for driving the member, a position detector and a controller. The actuator drives the member to move by an amount proportional to a given number of pulses. The position detector detects a position of the member in predetermined detection steps. The controller determines in steps smaller than the predetermined detection steps a target position up to which the member is to be moved. Then, it controls the actuator up to a detection-step position before the target position by closed-loop control in accordance with a detection result from the detector. Further, it controls the actuator from the detection step position to the target position by open-loop control.

Abstract: In a zoom lens system that consists of a plurality of lens units and that performs zooming by varying the distances between the lens units, one of the lens units other than the lens unit disposed at the object side end includes a hand-shake correction lens unit that is decentered in a direction perpendicular to the optical axis for hand-shake correction and a fixed lens unit that is disposed on the image side of the hand-shake correction lens unit and that is kept in a fixed position during hand-shake correction. With respect to the lens element disposed at the image-side end of the hand-shake correction lens unit and the lens element disposed next to the image-side surface of the former lens element and kept in a fixed position during hand-shake correction, the relations between their shape factors and refractive powers are defined.

Abstract: A viewfinding system for use with an optical system that creates a first object image includes an objective block which is sealed as a unit. The objective block includes a focusing screen for forming the first object image and relay optics for transmitting the first object image. A zoom block includes a zoom optical system for providing a modification of the magnification of the first object image to provide a second object image. An eyepiece block receives the second object image and includes a reflecting member and an eyepiece through which the second object image is observed. The eyepiece block is sealed and the second object image is realized within the sealed eyepiece block.

Abstract: A taking optical system capable of correcting an image blur resulting from vibration of the optical system consists of a first positive lens unit, a second negative lens unit, a third positive lens unit, and a fourth negative lens unit, and achieves zooming by varying distances between these lens units. The second lens unit includes a decentered lens element, which has a diffracting optical surface formed on its image-side surface, so that an image blur is corrected by decentering the decentered lens element translationally.

Abstract: A system includes a compensating lens unit capable of decentering for camera shake compensation and a non-decentering lens located closer to an image than the compensating lens unit and not decentering in camera shake compensation. An aspherical surface is formed in the compensating lens unit, and an aspherical surface which tends to counteract an aspherical effect of the aspherical surface formed in the compensating lens unit is formed in the non-decentering lens.

Abstract: An apparatus has a member to be driven, an actuator for driving the member, a position detector and a controller. The actuator drives the member to move by an amount proportional to a given number of pulses. The position detector detects a position of the member in predetermined detection steps. The controller determines in steps smaller than the predetermined detection steps a target position up to which the member is to be moved. Then, it controls the actuator up to a detection-step position before the target position by closed-loop control in accordance with a detection result from the detector. Further, it controls the actuator from the detection step position to the target position by open-loop control.

Abstract: In a camera having a function or recording a scope of printing (printing scope) in an exposed picture of a film, under a panoramic photography mode, that is, a mode in which the ratio of the horizontal dimension to the vertical dimension of a printing scope is larger than that of a standard picture from a film, an aperture is controlled to be smaller than in standard photography.

Abstract: A zoom viewfinder system for a single reflex camera comprises a relay optical system through which said first object image is formed as a second object image and plural reflecting members for reflecting light rays of said first object image, wherein the reflecting members except one reflecting member provided closest to a first object image is moved in order to adjust an angle of light rays of the first object image to the reflecting members. The zoom viewfinder system also comprises a holder for holding the reflecting members located parallel in the relay optical system in order to determine relative positions of the reflecting members precisely. The zoom viewfinder system further comprises holding members for holding plural parts of an optical system respectively, wherein each part is fixed to compose a viewfinder system, so that assembly and maintenance can be easy and the optical axis can be prevented from deviating.

Abstract: In a telescope, the adjustment order is limited so that dioptric power adjustment is made after adjustment of a distance between a pair of optical systems is completed. A pupil distance and a dioptric power correction amount are stored in a memory for every user. When a user uses the telescope, his or her pupil distance and dioptric power correction amount are read out from the memory to automatically make adjustment.

Abstract: A camera shake compensating optical system has a first lens and a second lens from the object side. The image side surface of the first lens is convex to the object side. The object side surface of the second lens is convex to the object side. A direction in which a luminous flux is transmitted is slightly changed by a relative displacement of the second lens with respect to the first lens. By an obtained transmission deflection angle, blur of an image taken when the taking optical system is inclined is compensated for. The relative displacement is made so that an incident surface of the first lens and an exit surface of the second lens are not decentered from the optical axis of the taking optical system.

Abstract: A finder optical system is shown which includes a photo-taking lens, a mirror reflecting light rays passed through the photo-taking lens upward, a focusing screen on which a first object image is formed, a relay lens system through which the first object image is reformed as a second object image smaller than the first object image, and an eye piece which enlarges second object image. The relay lens system is located above the focusing screen and parallel to an optical axis of the photo-taking lens. The finder optical system allows for compactness in both depth and height.

Abstract: A camera having a learning function which automatically sets data for current photographing in accordance with a tendency of data set in the past (learned data) and takes a photograph in accordance with the data thus set.

Abstract: A camera having an auto zoom function includes: a taking lens for photographing an object; a distance measuring device for measuring a distance to the object; a magnification setting device for setting a photographing magnification for the object; and a focal length calculator for calculating a focal length of the taking lens to obtain the photographing magnification set with respect to the distance to the object. Auto zoom operation is carried out by automatic movement of the taking lens so that the focal length of the taking lens may be equal to the calculated focal length.

Abstract: An auto focus camera includes a usual zoom lens and provides a pseudo focal length mode, in which the size of focus condition detecting area, to the photographing scene to be printed, is variable. A pseudo focal length is stored and a focus condition is detected in accordance with a ray of light passed through the zoom lens. When the camera is in such a mode as to continuously detect focus condition for keeping an object in focus, or to be operated when the contrast of the object whose focus condition is detected is low, the focal length of the zoom lens and the pseudo focal length are controlled respectively in accordance with the mode.