Abstract: An optical instrument equipped with a zoom lens installed in a zoom lens barrel having a lens guide arrangement for zooming up and down and focusing which includes a zooming-up guide path for guiding the lens group and positioning it in one of fixed zoom positions during zooming-up, a zooming-down guide for guiding the lens group and positioning it in one of fixed zoom positions during zooming-down, and focusing guide paths arranged parallel to one another and connect the zooming-up and zooming-down guide path in the fixed zoom position for guiding the lens group during focusing after zooming up or down to one of the fixed zoom position.

Abstract: An electronic flash unit is caused to perform a pre-flash immediately before a photographing operation, and the quantity of light reflected by the subject during the pre-flash is measured by a flash metering unit. Based upon the output from the flash metering unit, a decision is made as to whether or not another pre-flash is to be implemented. Based upon the results of the decision-making, another pre-flash is performed if necessary. Thus, if the quantity of light measured by the flash metering unit during the pre-flash is too small or too large and a sufficient degree of accuracy is not achieved in the measurement, another pre-flash is performed to assure a high degree of accuracy in metering.

Abstract: A zoom lens device has a zooming position detector consisting of a code plate and a brush device. The code plate is mounted to a front face of a shutter unit that is attached to a front end of an axial movement barrel. The axial movement barrel is located inside a helical movement barrel so as to be immovable in the axial direction relative to the helical movement barrel, but is rotated relative to the helical movement barrel for zooming. The brush device is mounted to an inner peripheral portion of a lens barrel that is located near the face of the shutter unit and rotates relative to the face of the shutter unit, such that the electric contact strips brush the code plate while the shutter unit rotates relative to the lens barrel for zooming. A zooming position of the zoom lens device is determined based on output signals from the brush device.

Abstract: A gas pressure-reducing valve in which a valve member to be seated on a valve seat having a valve hole opened at its central portion and leading to a pressure-reducing chamber between a body and a diaphragm is fixed on a valve stem connected to the central portion of the diaphragm and arranged coaxially with the valve axis. A bottomed mounting bore which is aligned with the valve axis and opened toward the pressure-reducing chamber is formed in the body. A cylindrical valve seat member forming a valve chamber between itself and the closed end of the mounting bore for accommodating the valve member and inserted into the mounting bore is fixed on the body. A valve seat facing the valve chamber is formed on the inner surface of the end portion of the valve seat member on the side of the pressure-reducing chamber. This arrangement makes it possible to reduce the number of parts and to enhance the degree of freedom for the arrangement of the parts in the body.

Abstract: A gas pressure-reducing valve in which a valve member to be seated on a valve seat opened at its central portion with a valve hole leading to a pressure-reducing chamber between a body and a diaphragm is fixed on a valve stem coaxially extending through the valve hole, and in which the valve stem is fastened to a fastened member fixed on the central portion of the diaphragm. The fastened member is provided with a fitting bore opened at its one end on the side of the valve stem and a bottom threaded bore having a diameter smaller than that of the fitting bore and coaxially leading to the other end of the fitting bore. The valve stem is provided at its end portion on the side of the diaphragm with a fitting stem portion to be fitted in the fitting bore and an externally threaded portion capable of being screwed in the threaded bore and coaxially leading to the fitting stem portion. The externally threaded portion has a shorter axial length than that of the fitting bore.

Abstract: A flash control device for a camera includes a light emission unit which emits light to illuminate a subject to be imaged by the camera, a preliminary light emission control unit which causes the light emission unit to emit light during a preliminary light emission operation prior to a main exposure operation to be performed by the camera and until a predetermined amount of light is received by the camera during the preliminary light emission operation, a range computing unit which computes a distance from the camera to the subject, an exposure calculation unit which computes an aperture value for the camera during the preliminary light emission operation, a main light emission calculation unit which calculates a length of time that the light emission unit is to emit light during a main light emission operation based on the preliminary light emission operation, the computed distance to the subject, and the aperture value, and a main light emission control unit which controls the emission of light by the light

Abstract: A zoom lens device has a zooming position detector consisting of a code plate and a brush device. The code plate is mounted to a front face of a shutter unit that is attached to a front end of an axial movement barrel. The axial movement barrel is located inside a helical movement barrel so as to be immovable in the axial direction relative to the helical movement barrel, but is rotated relative to the helical movement barrel for zooming. The brush device is mounted to an inner peripheral portion of a lens barrel that is located near the face of the shutter unit and rotates relative to the face of the shutter unit, such that the electric contact strips brush the code plate while the shutter unit rotates relative to the lens barrel for zooming. A zooming position of the zoom lens device is determined based on output signals from the brush device.

Abstract: The present invention is directed to a zinc-molybdenum-based dithiocarbamate derivative which is a complex salt having the metallic components of zinc and molybdenum in the same molecule. When used as a lubricant additive, it imparts a notable friction-reducing effect to the lubricant composition in which it is incorporated, reducing its friction coefficient and improving its stability of friction coefficient at both low and high temperature, particularly at high temperature. In particular, it improves friction-related characteristics much more notably than a combination of a molybdenum and zinc compound.

Abstract: A photometry device of a camera has a photometry circuit which measures the luminance value of the object field, a colorimetry circuit which measures the color balance of the object field, and a scene discrimination unit which discriminates the scene on the basis of the output from the colorimetry circuit. The device calculates the proper exposure value of the object field on the basis of the outputs from the photometry circuit and scene discrimination unit. Scene discrimination is preferably made using photographing mode information, photographing distance information, or current time information to improve discrimination accuracy.

Abstract: A photometric circuit performs photometry on an object field using an accumulating photometric element, such as, for example, a CCD. An accumulation controller controls the photometric circuit. An abnormality sensor determines whether an abnormality, such as, for example, the inversion effect of the photometric output of the photometric circuit has occurred. The accumulation controller sets the accumulation time of the photometric element for the next round of photometry to a minimum value, for example, when it has been determined by the abnormality sensor that an abnormality has occurred. This allows the photometric circuit to return to normal operation as quickly as possible.

Abstract: A zoom lens device has a zooming position detector consisting of a code plate and a brush device. The code plate is mounted to a front face of a shutter unit that is attached to a front end of an axial movement barrel. The axial movement barrel is located inside a helical movement barrel so as to be immovable in the axial direction relative to the helical movement barrel, but is rotated relative to the helical movement barrel for zooming. The brush device is mounted to an inner peripheral portion of a lens barrel that is located near the face of the shutter unit and rotates relative to the face of the shutter unit, such that the electric contact strips brush the code plate while the shutter unit rotates relative to the lens barrel for zooming. A zooming position of the zoom lens device is determined based on output signals from the brush device.

Abstract: Proper exposure is obtained even when the mirror down time is short, which occurs, for example, during continuous photography. This is achieved, for example, by determining the accumulation time and gain for a subsequent round of photometry based on whether a photometry prohibiting signal interrupted the current round of photometry. Additionally, the photometry parameters that are used for photometry can be changed (or set) based on changes in the film feed mode of the camera. The camera can include a photometry circuit that performs photometry on an object field using an accumulating type of photometry element. An accumulation controller controls the start and finish of the accumulation of the photometry element. A feed mode setting device is capable of setting a film feed mode from among a plurality of film feed modes.

Abstract: An initial position of a variable focus lens is set substantially halfway between a wide and a telephotographing end. Thus, just after the initial position is set by turning on a power switch, both the wide photographing and the telephotographing can be performed quickly. The instantaneous change of a moving object can be quickly photographed in a desired visual field. In the present invention, a composition at the initial position which is set by turning on the power switch is not so different from a composition at the wide photographing side or the telephotographing side. Therefore the user is not confused by any composition during photographing.

Abstract: A zoom lens device has a helical movement barrel and a drive ring mounted in a fixed barrel to be rotatable about an optical axis. The helical movement barrel holds front and rear lens groups therein. The drive ring is rotated by a motor through gears. The drive ring is coupled to a helical movement barrel with a clearance in the circumferential direction, so the drive ring can rotate relative to the helical movement barrel within an angle defined by the clearance. While the drive ring rotates relative to the helical movement barrel, the rotational movement of the drive ring causes a cam barrel to move along the optical axis relative to the helical movement barrel. The axial movement of the cam barrel causes the rear lens group to move along the optical axis. When the drive ring is rotated beyond the angle defined by the clearance, the rotational movement of the drive ring causes the helical movement barrel to rotate together with the cam barrel.

Abstract: A control circuit generates a control signal which is of a low level during a certain period of time after the power supply of a solid state imager has been turned on or a power save mode thereof has been canceled, and of a high level after elapse of the period of time. Based on the control signal, a timing generator generates transfer clock signals having a high frequency than when the solid state imager is in a normal transfer mode, and applies the transfer clock signals to a CCD shift register to remove or transfer excessive invalid charges at a high rate therefrom. After the power supply has been turned on or the power save mode has been canceled, therefore, the time required to bring the solid state imager into a condition capable of imaging a subject is shortened.

Abstract: A photometry device includes a light-receiving element that photoelectrically converts light from the subject field and outputs an electrical signal corresponding to the intensity of the light. The light-receiving element is provided with at least one light-receiving pixel that is optically shielded from the light A photometry value input unit inputs the photometric output from the light-receiving element. An accumulation time setting unit sets the accumulation time of the light-receiving element on the basis of the output of the photometry value input unit, and computes the setting value of the accumulation time on the basis of the output of the light-receiving pixel.

Abstract: A photometric apparatus is capable of obtaining a precise photometric value without any saturation of a photometric output value even when measuring a light intensity of a flicker light source. The photometric apparatus has a photometric portion for measuring the field by use of a charge type photometric device, and a charge time determining portion for determining a value of a next charge time of the photometric device on the basis of an output value of the photometric portion and a value of the charge time at that time. The charge time determining portion determines the value of the next charge time so that a photometric output value in the next photometric process approximates a predetermined target value.

Abstract: A camera having a line of sight detecting device, includes a line of sight detection portion for detecting the line of sight position of a photographer, a portion of selection of a line of sight mode for selecting one of a single mode for locking a line of sight position obtained when a plurality of previous detection results of the line of sight detection portion satisfy a predetermined eye-gazing condition and a continuous mode for renewing the line of sight position on the basis of the latest line of sight position from the line of sight detection portion, a control mode setting portion for selecting a control mode for setting a camera phototaking condition, and a phototaking control for setting the camera phototaking condition in accordance with the line of sight position of the photographer when the control mode is selected, wherein when the control mode is selected by the control mode setting portion, the continuous mode is selected by the portion of selection of a line of sight mode, and the camera pho

Abstract: A chromatic balancer determines an optimal chromatic balance between strobe illumination and light illumination during balance synchro photography. A photometric detector measures the amount of light from one or more regions in the scene to be photographed. A chromatic balance calculator determines the chromatic balance of the photograph scene. A background exposure correction value calculator determines a background light exposure correction value. A flash level correction value calculator determines a flash level correction value.

Abstract: In a case in which the photometry region selected through a photometry region selection part is in the center of the screen, body spot photometry is selected for photometry of the object field, using luminous flux not passing through the screen. In all other cases, an output is selected for photometry of the image of the object field formed on the screen.