摘要:
A video camera has an automatic focusing system provided with a focus detecting section for calculating and outputting a focus signal corresponding to a focus condition of an picked-up image from a video signal produced by an image pickup element. Either the image pickup element or a focusing lens in a photographic lens is oscillated back and forth of its present position, as needed, to detect an in-focus direction at the moment. The focusing lens is moved in the in-focus direction up to a position at which an optimum focus condition is obtained.
摘要:
A zoom lens driving apparatus always detects a position of an image magnification varying lens section, and drives the image magnification varying lens section in accordance with a preset relationship between the position of the image magnification varying lens section and a zoom driving speed in such a manner that the driving speed becomes higher on one side, where the focal length of the zoom lens corresponding to the position of the image magnification varying lens section is small, than on another side where the focal length is large. Accordingly, the amount of focal shift, which in the zoom lens of the inner focusing system would otherwise abruptly increase with increasing focal length, is significantly suppressed, so that an auto focus adjusting mechanism or a focus correcting device effective during zooming, provided in the zoom lens, can function satisfactorily as to follow the focal shift of the zoom lens, whereby the lens control of a superior response can always be achieved.
摘要:
A semiconductor light position detector for a rangefinder which projects a light beam onto an object and receives a reflected light beam from the object to measure a distance to the object. A portion of the light-receiving surface of the detector on which the reflected beam will not form a light spot is partially covered with a member that blocks unwanted light. Thus, the malfunctions caused by the flare component of the light from the light projector and the malfunctions due to increases in the shot noise under a high illuminance are reduced greatly.
摘要:
This invention provides a surface acoustic wave device which comprises a multi-layered substrate. The multi-layered substrate comprises at least a piezoelectric zinc oxide layer, an intermediate silicon oxide layer and an .alpha.-Al.sub.2 O.sub.3 base made of a single crystal havine an (0112) crystallographic plane or an equivalent crystallographic plane. This surface acoustic wave device is operable at ultra-high frequency.
摘要翻译:本发明提供了一种包括多层基板的表面声波装置。 多层基板至少包括压电氧化锌层,中间氧化硅层和由单晶铪(0112)晶面或等效晶面制成的α-Al 2 O 3基底。 该声表面波装置可以超高频工作。
摘要:
Provided from the object side are a first lens group (11) having a positive refracting power and fixed to the image plane, a second lens group (12) having a negative refracting power and a magnification varying action exhibited when moving along the optical axis, a third lens group (13) fixed to the image plane and having a positive refracting power, and a fourth lens group (14) movable along the optical axis so as to maintain the image plane moving with the movements of the second lens group (12) and of the object in a fixed position from a reference plane. Hence the movement of the image due to camera shake is corrected by moving the whole third lens group (13) vertically to the optical axis. The size is reduced and the aberrations are small because the whole groups whose optical performance is united are decentered.
摘要:
A zoom lens is described that includes: a first lens group having positive refracting power and fixed with respect to an image plane; a second lens group having negative refracting power and varying power, wherein the power is varied by moving along an optical axis; a third lens group having positive refracting power and fixed with respect to the image plane; and a fourth lens group having: positive refracting power and moving along an optical axis so as to keep the image plane varied by movement of the second lens group and an object at a predetermined position from a reference surface. The first, second, third, and fourth lens groups are disposed from the object side to the image plane side in this order. The second lens group is composed of two negative lenses and one positive lens. The third lens group is composed of two positive lenses and one negative lens. The fourth lens group is composed of a positive lens. The second to fourth lens groups include at least one aspherical surface, respectively.
摘要:
A device for calculating diffraction efficiencies of a diffraction lens divided into a plurality of regions, each region comprising at least one grating ring, comprises a first memory for storing information about diffraction efficiencies of the regions; a second memory for storing information about weights corresponding to the regions; and a first processor for retrieving information from the first and the second memory, and calculating diffraction efficiencies of the entire diffraction lens using the formula E j = ∑ m = 1 M W m η mj ( 1 ) wherein: j: integer indicating the order of diffraction light Ej: diffraction efficiency for j-th order diffraction light of the diffraction lens M: positive integer (M>1) indicating the number of regions for which the diffraction efficiency is calculated m: index of the region for which the diffraction efficiency is calculated &eegr;mj: diffraction efficiency for the j-th order diffraction light of the m-th region (stored in the first memory) Wm: weight for the m-th region (stored in the second memory means). Thus, the diffraction efficiency of the diffraction lens can be calculated easily.
摘要:
A projection lens for projecting an image appearing on a cathode-ray tube onto a screen, small in residual aberrations, having a high imaging performance, also having a large aperture ratio and a wide field angle, suitable for a video projector having a high definition of, say, 1,125 scanning lines. The projection lens has, successively from the screen side, a Gauss type lens system, a positive lens mainly for enlarging the aperture ratio, and a negative lens mainly for widening the field angle, which negative lens has a strongly concave surface at the screen end.
摘要:
A surface acoustic wave device comprising a piezoelectric substrate which comprises an .alpha.-alumina layer as a base region and a zinc oxide layer as a surface region formed on the .alpha.-alumina layer. Preferably the two layers are each made of a single crystal, and the thickness of the zinc oxide layer and an angle between a crystallographic axis of the zinc oxide single crystal and the direction of wave propagation are determined so as to fall within optimum ranges, respectively. This device features an increased phase velocity and an augmented value for the electromechanical coupling coefficient and accordingly is of use at very-high to ultra-high frequencies.
摘要:
Provided from the object side are a first lens group (11) having a positive refracting power and fixed to the image plane, a second lens group (12) having a negative refracting power and a magnification varying action exhibited when moving along the optical axis, a third lens group (13) fixed to the image plane and having a positive refracting power, and a fourth lens group (14) movable along the optical axis so as to maintain the image plane moving with the movements of the second lens group (12) and of the object in a fixed position from a reference plane. Hence the movement of the image due to camera shake is corrected by moving the whole third lens group (13) vertically to the optical axis. The size is reduced and the aberrations are small because the whole groups whose optical performance is united are decentered.