Abstract:
The present invention provides an image pickup lens with a large focal depth from the center to the outer part of an image plane formed on an image sensor and capable of maintaining its focal depth within a practical range and thus suppressing a decline in the resolution. An image pickup lens 7 includes, in order from the object side to the image plane side, an aperture stop 5, a first lens 1 that is a biconvex lens having positive power, a second lens 2 that is a meniscus lens having negative power and whose lens surface facing the object side is convex, a third lens 3 that is a meniscus lens having positive power and whose lens surface facing the object side is concave, and a fourth lens 4 that is a biconcave lens having negative power. The image pickup lens 7 includes a multifocal lens on the lens surface of the first lens 1 facing the object side. D and Ymax satisfy the following conditional expression (1): 0≦D/Ymax≦0.1 (1) where D is an absolute value of the distance between the multifocal lens surface and a surface of the aperture stop on the optical axis, and Ymax is the absolute value of the maximum image height on an image plane formed on the image sensor.
Abstract:
The electronic flash unit disclosed comprises: a transformer (14) to vary voltages of a power supply; an accumulator (16) composed of a main capacitor (17) to charge an electric energy supplied from the transformer (14); a lamp unit (4) provided with a flashlamp (20), set inside of a reflector (19), that flashes by discharging of energy storages in the main capacitor (17) upon applying a voltage on a trigger terminal (21); and a trigger circuit (10) to generate the voltage to apply on the trigger terminal (21), wherein at least the lamp unit (4) is coated with an insulation material.
Abstract:
In an electronic flash device of the type in which depending upon the exposure conditions an electronic flash lamp converts into light the energy stored on a main flash capacitor or the energies stored not only on the main flash capacitor but also on an auxiliary flash capacitor, a switching element which is turned on or off so as to permit or interrupt the discharge of the auxiliary flash capacitor is controlled by a simplified control circuit comprising a switching element control circuit which delivers a low voltage supplied from a low-voltage power source to the switching element as a turn-on signal and a detection circuit which controls the switching element control circuit in response to the exposure conditions such as a distance to a subject or a selected aperture. Therefore, an inversion circuit which is used in the prior art electronic flash devices can be eliminated.
Abstract:
A camera lens unit includes a first lens including a first lens section having a first optical axis along which light runs, and a second lens. The second lens includes a second lens section having a second optical axis along which the light runs, a flange provided on an outer circumference of the second lens and having a surface facing the first lens, and a cylindrical section having an inner circumference extending from the flange along the second optical axis. The inner circumference of the cylindrical section faces the second lens section. The first lens contacts the inner circumference of the cylindrical section of the second lens and is engaged into the cylindrical section. The cylindrical section of the second lens includes plural protrusions protruding along the second optical axis, such that plural crenels are provided between the protrusions and have heights along the second optical axis lower than the protrusions. The camera lens unit prevents diffuse reflection caused by unnecessary incident light.
Abstract:
The electronic flash unit disclosed comprises: a transformer (14) to vary voltages of a power supply; an accumulator (16) composed of a main capacitor (17) to charge an electric energy supplied from the transformer (14); a lamp unit (4) provided with a flashlamp (20), set inside of a reflector (19), that flashes by discharging of energy storages in the main capacitor (17) upon applying a voltage on a trigger terminal (21); and a trigger circuit (10) to generate the voltage to apply on the trigger terminal (21), wherein at least the lamp unit (4) is coated with an insulation material.
Abstract:
In a motion verifying photography method, a latent image is captured during a film exposure time interval. The film exposure time interval has an initial portion, a middle portion, and a final portion. A first digital image is captured during the initial portion of the film exposure time interval. A second digital image is captured during the final portion of the film exposure time interval. A representation of both electronic images is visualized. A motion verifying camera has an exposure frame, an electronic array imager spaced from the exposure frame, an optical system directing light along a first path to the exposure frame and along a second path to the imager. Shutters are disposed on both paths. A shutter release connects to an actuator and responsive to the actuator, momentarily opens the film shutter for a film exposure time interval having an initial portion, a middle portion, and a final portion. The actuator momentarily opens the imager shutter during the initial portion and momentarily opens the imager shutter during the final portion.
Abstract:
Electric zoom camera wherein zooming speed is not influenced even by drop of power source voltage, by driving its zooming electric motor by an electric pulse current such that the period (T.sub.0, T.sub.1, T.sub.2, - - -) is defined by present period of a lens position signal "b" from a lens position detector (2) which consists of a photo-interrupter and a photo-coupler, and each of the period length is divided into a first portion (Po) (off-portion) wherein motor current is off and a second portion (Pd) (duty portion) wherein the motor current is on, the length of the first portion (Po) being adjusted responding to the present zooming speed obtained from the lens position signal outputted from the lens position detector (2).
Abstract:
An imaging apparatus is composed of a lens holder (3) arranged concentrically with an imaging element (2); a lens barrel (4) which has an imaging lens removably inserted from the leading end section side of the lens holder (3); a cover (6) removably fitted at the leading end section of the lens holder (3); and a cam mechanism section arranged on the lens barrel (4), the lens holder (3) and the cover (6) so that the lens barrel (4) turns around the optical axis to the imaging element (2) and that the lens barrel moves in the optical axis direction by such turning. The cam mechanism section is composed of a first cam surface (10a) formed on the inner circumference surface of the lens holder (3); a cam protruding section (10b) formed on the outer circumference surface of the lens barrel (4); and a second cam surface (10c) formed on the inner surface of the cover (6). The cam mechanism section smoothly turns the lens barrel (4) around the optical axis and moves the lens barrel in the optical axis direction. The cam mechanism section can be easily manufactured at low cost.
Abstract:
A lens unit including a first lens including a first lens section having a first optical axis along which light passes, and a second lens. The second lens includes a second lens section having a second optical axis along which light passes, and a flange provided at the outer circumferential part of the second lens section and having a surface opposed to the first lens, and a tubular section extending from the flange in the direction of the second optical axis and having an inner side face opposed to the second lens section. The first lens is fitted in the tubular section and in contact with the inner side face of the tubular section of the second lens. The tubular section of the second lens has a plurality of protrusions protruding in the direction of the second optical axis and a plurality of valleys provided between the protrusions.
Abstract:
An image-capturing device includes a detector which detects that a resistance value of an actuator, made of shape memory alloy, is maintained within a predetermined range. The image-capturing device moves a lens step by step from a place corresponding to a first field in order to obtain image data from each one of the fields provided in a focus region. The image-capturing device also calculates a target place, where the lens should be finally positioned, by using the obtained image data, and then positions the lens at the calculated target place. The foregoing structure allows obtaining reliable and stable data.