Abstract: An optical device having a variable optical surface is given by the combination of an elastic body and a relatively rigid member having an opening and disposed to contact the elastic body to expose a part of the surface of the elastic body. The exposed surface part forms a variable optical surface, the shape of which is changed by deforming the elastic body to vary the focal length.

Abstract: A variable-focus optical device comprises an elastomeric member having a gradient of shear modulus along its optical axis, and a deforming member having an aperture adapted for causing projection or sinking of the elastomeric member therethrough or thereat to deform the surface of the elastomeric member. The gradient of shear modulus is preferably one of continuously decreasing from the surface toward the inside of the elastomeric member. The gradient of shear modulus is provided by a concentration gradient of an inorganic substance such as silica dispersed in an elastomeric substance such as polysilioxane.

Abstract: An array lens comprises a member having a plurality of arranged openings, an elastic member provided in intimate contact with the member and having its surface shape deformable by an extraneous pressure, and means for imparting a force to the elastic member to deform the surface shape of the elastic member in the openings of the member.

Abstract: An optical device having an elastic body sandwiched between typically two optical surfaces, which are capable of changing relative positions through deformation of the elastic body. The two optical surfaces may be given by, for example, parallel flat plate glasses or lenses. By changing the distnace or relative positions between the two optical surfaces, focusing or correction of chromatic aberration of photographic lenses, etc. can be effected.

Abstract: This specification discloses a single lens having an index gradient in a direction perpendicular to the optic axis thereof, and the surface of the single lens on the light beam incidence side when the single lens is used at a reduced magnification is formed into a surface concave relative to the object side, whereby the working distance is sufficiently long and aberration are well corrected.

Abstract: A functional optical element comprises a first optical member, a second optical member provided in contact with said first optical member, the interface between said first optical member and said second optical member being non-flat planar, a means for changing the refractive index of said second optical member, said means for changing refractive index being capable of creating selectively a first state in which said first optical member and said second optical member have an equal refractive index and a second state in which said first optical member and said second optical member have different refractive indices by changing the refractive index of said second optical member.

Abstract: Optical modulation is carried out by providing a transparent member having a surface, providing an elastomeric body disposed spaced apart from the surface, irradiating the surface with a light beam, and causing the elastomeric body to contact the surface so that the proportion of the light beam transmitted through the surface is changed.

Abstract: A variable focal length lens in which a lens comprising a transparent elastic member having a non-uniform distribution of refractive index is adapted to be deformed by an extraneous force.

Abstract: A focus detecting device comprises an image sensor; sharpness detecting means for detecting the sharpness of an image from image signals obtained from the image sensor; in-focus state identifying means for identifying an in-focus state of the image on the image sensor by comparing plural values of sharpness detected in different focus states; and focus state control means for varying the focus state during a period t at an interval T, wherein t<T, and maintaining a fixed focus state during a period T-t.

Abstract: An electrophotographic apparatus has illuminating means for illuminating an original, scanning means for scanning the original, imaging means for imaging the reflected light or the transmitted light from the original on a light-receiving member, the imaging means having at least one variable refractive power element, control means for varying the refractive power of the variable refractive power element, and driving means for moving the light-receiving member in synchronism with the scanning of the original.

Abstract: An afocal variable magnification optical system has a first optical system having at least one variable refracting power element; and a second optical system.

Abstract: A gradient index lens includes first and second flat end faces. A refractive index N(.gamma.) at a position deviated by a distance .gamma. from an optical axis of the lens is given asN(.gamma.)=N.sub.0 +N.sub.1 .gamma..sup.2 +N.sub.2 .gamma..sup.4 + . . .for N.sub.1 <0where N.sub.0, N.sub.1, N.sub.2, . . . are constants, and the following conditions are satisfied: ##EQU1## where f is a focal length of the lens, a is an effective lens diameter, Sk' is a work distance, and .lambda. is a wavelength in units of microns.

Abstract: In a gradient index type single lens having a gradient index in a direction perpendicular to the optic axis thereof, the surface of the single lens on the light beam incidence side when the single lens is used at a reduced magnification forms a planar surface, the surface of the single lens on the light beam emergence side forms a convex surface and are satisfied the following conditions:0.55.ltoreq.(1-N.sub.0).multidot.f/r.sub.2 .ltoreq.1.200.8.ltoreq.d/f.ltoreq.2.2where r.sub.2 is the radius of curvature of the surface on said light beam emergence side, d is the thickness of the single lens, N.sub.0 is the on-axis refractive index of the single lens, and f is the focal length of the single lens.

Abstract: The disclosure relates to a rotary indicating device preferably in use, for example, for wheel covers for motor vehicles. The device includes a base member having an indication region and adapted to be rotated about a rotary axis. The indication region indicates a desired image and comprises a plurality of reflection faces. The reflection faces are inclined in the same direction and also at the same angle with respect to a standard plane perpendicular to a rotary axis of the base member. Thus, when the base member rotates, the observer can visually recognize the image as a clear single image due to the after image phenomenon.

Abstract: An apparatus for covering a disc wheel supporting a tire for a motor vehicle has a wheel cover mounted on the disc wheel and covering an outer side of the disc wheel, and at least one ventilation opening in the wheel cover for communicating the inside of the wheel cover with the atmosphere. The apparatus is provided with a closing plate for closing the ventilation opening when a temperature inside the wheel cover is not more than a predetermined temperature and opening the ventilation opening when the temperature inside the wheel cover is more than the predetermined temperature. A heat sensing member, which may be made of a shape memory effect alloy is connected to the closing plate and deforms when the temperature inside the wheel cover is more than the predetermined temperature so as to displace the closing plate away from the opening to open the opening.

Abstract: An optical system for scanning a medium with a beam spot includes a light beam generator, a deflector for deflecting the light beam in a predetermined direction and in deflection plane, and an imaging optical system between the deflector and the medium for imaging the light beam from the deflector on the medium as a beam spot, the imaging optical system having at least one lens element mode of a moisture absorbing material. The lens element has a shape in which the dimension in a direction parallel to the deflection plane of the light beam is greater than the dimension in a direction perpendicular to the deflection plane of the light beam. A device mitigates any influence on the imaged condition of the light beam on the medium caused by the lens element being subjected to moisture.

Abstract: A colored image reading apparatus has a light source for illuminating the surface of an original, a transmitting optical system for dividing the light beam from the surface of the original into two beams of short wavelength zone and long wavelength zone and transmitting them to a light detector, a processing circuit for effecting an operation between the signals from the light detector and obtaining a plurality of electrical signals, and a converter circuit for converting the plurality of electrical signals into signals corresponding to respective colors, and is capable of well discriminating and reading four colors, black, blue, red and white, by selecting to predetermined values the wavelength .lambda.'b of the overall spectral characteristic on the short wavelength zone side including all of the spectral characteristics of the light source, the transmitting optical system and the light detector relative to the maximum value of the transmission factor and the wavelength .lambda.

Abstract: A communication system between mobile and wayside stations wherein the mobile stations are traveling on a track which is divided into sections by means of an open-type transmission line paralleling the track. A frequency selection and conversion device for each section of transmission line or track is connected to the transmission line to define the length of each section. A series of lower frequency carriers transmitted on the line are allotted respectively to each specific section of transmission line. These low-frequency carriers travel with a low loss along the transmission line and they are selected and converted by their respective frequency selection and converter device to a common high-frequency carrier signal for leaky transmission to a mobile station on the corresponding track section.