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 zoom lens comprising, in the order of an increasing distance from an object; a fixed first lens group (1) having a positive refractive power; a second lens group (2) containing an aspherical surface, having a negative refractive power and being in charge of a variable power action by being moved; a fixed third lens group (3) containing an aspherical surface and having a positive refractive power; and a fourth lens group (4) containing an aspherical surface, having a positive refractive power and moving while following up a moving object point; wherein the surface on the image plane side of a lens positioned closest to the image plane in the third lens group (3) has a concave plane having a strong refractive power with respect to the image plane and a relation, 2.0
摘要:
In a wavelength-selective phase-grating type optical low-pass filter including at least a pair of adjacent first and second transparent layers, there is provided at least one adhesive layer through which a pair of adjacent first and second transparent layers stacked on each other in a phase grating form for generating a phase difference distribution on the boundary surface between the pair of adjacent first and second transparent layers. The optical low-pass filter satisfies the following conditions under a condition of 470 nm .nu.d2, and (c) 0.9
摘要翻译:在包括至少一对相邻的第一和第二透明层的波长选择相位光栅型光学低通滤波器中,设置有至少一个粘合剂层,一对彼此堆叠的相邻的第一和第二透明层 用于在所述一对相邻的第一和第二透明层之间的边界表面上产生相位差分布的相位光栅形式。 光学低通滤波器在470nm <λ<580nm的条件下满足以下条件:(a)No(λ)= Ni(λ),(b)nu d1 nu d2, 和(c)0.9
摘要:
A very compact zoom lens system is provided which has a zoom ratio of 10.times., a bright f-number of 1.4 and a wide angle of view of 59 degree or greater although having a fewer number of lens. The zoom lens system comprises from the object side to the image side: a fixed first lens unit having a negative power lens, a positive power lens and a positive power meniscus lens; a second lens unit having an aspherical surface, having a negative power lens, a negative power biconcave lens and a positive power lens and performing zooming by moving; a fixed third lens unit having an aspherical surface and having a positive power lens, a positive power lens and a negative power lens; and a fourth lens unit having an aspherical surface, having positive power and moves according to zooming and a movement of an object point. The image side surface of the most image side lens of the third lens unit is a concave surface having strong power to the image side. When the focal length at the wide-angle limit is fw, the angle of view at the wide-angle limit is .omega., the focal length of the first lens unit is f1 and the focal length of the second lens unit is f2, the following condition is satisfied:0.17
摘要:
A first lens group having a negative refracting power and a second lens group having a positive refracting power are arranged in order from the photographing object side. Zooming is performed by changing the aerial interval between the first and second lens groups, and both the first and second lens groups have one or more aspheric surfaces. The first lens group includes two negative lenses and a positive lens which are arranged in order from the object side, and the second lens group includes a positive lens, a cemented lens having a positive lens and a negative lens, and a positive lens which are arranged in order from the object side.
摘要:
A wavelength-selective phase-grating optical low-pass filter has a phase difference structure formed at a boundary face between two layer materials which have different refractive index distributions and an identical refractive index at an intended wavelength. A trapezoid form is adopted at the phase difference section of the phase grating to achieve an excellent MTF characteristic in the condition of: ##EQU1## thereby obtaining a wavelength-selective phase-grating optical low-pass filter capable of adjusting the cutoff characteristic and improving the characteristic in the low-frequency region of the spatial frequency.
摘要:
A compact zoom lens comprising a small number of lenses, providing an aperture of about F1.4 and a zoom ration of about 14, with a full angle of view at the wide angle end of 64.degree. or wider. The zoom lens of the present invention comprises, aligned respectively from the object side, a fixed first lens group, comprising a lens with a negative refracting power, a lens with a positive refracting power, and a meniscus lens with a positive refracting power; a movable second lens group to provide zooming effect, comprising a lens with a negative refracting power, a biconcave lens with a negative refracting power, and a lens with a positive refracting power, with at least one surface of these lenses aspheric; a fixed third lens group with a positive refracting power, with at least one surface of these lenses aspheric; a fourth lens group, movable for compensating the position of the focal plane, with a positive refracting power, with at least one surface of the lenses aspheric. The below mentioned formula (1) is satisfied,0.1
摘要:
A plurality of types of ink having different wavelength characteristics are used for multiple printing of code information. When two or more types of ink are to be printed in an overlapping manner, in a region 8 in which one type of ink 4 and another type of ink 5 are printed in the overlapping manner, the ink 4 and the ink 5 are printed so as not to completely overlap each other by using a checkered pattern 9. As a result, the multiple printing can be performed without strict constraints on the wavelength characteristics of the ink.
摘要:
A two-dimensional optical low-pass filter includes an optical phase grating having a plurality of unitary grating periods on only one side of a grating plane. Each of the unitary grating periods includes at least two phase retardation structures spaced from each other, thereby providing phase retardation across the grating plane. The two phase retardation structures invariably have at least one non-continuous phase retardation configuration substantially in all directions on the grating plane.
摘要:
A zoom lens assembly includes, in succession order from the object side, a first fixed lens group of a positive refractive power including a negative lens, a positive lens and a positive meniscus lens; a second movable lens group of a negative refractive power including a negative meniscus lens, a positive lens and a positive lens for effecting a variation of image magnification by moving along an optical axis of the zoom lens assembly; a third fixed lens group of a positive refractive power having at least one aspherical face and including a positive lens and a negative lens; and a fourth movable lens group of a positive refractive power including having at least one aspherical surface and also including negative and positive lenses cemented together.