摘要:
A zoom lens assembly comprises a photo-taking optical system having a focusing portion, a zooming portion, and an optic axis, a manual operator movable in the direction of the optic axis for zooming and rotatable about the optic axis for focusing, an electrically rotated drive shaft, a member for moving the zooming portion of the photo-taking optical system for zooming in response to the movement of the manual operator in the direction of the optic axis, an intermediate member rotatable in response to the rotation of the manual operator to move the focusing portion of the photo-taking optical system for focusing, and movable in the direction of the optic axis with the manual operator, a transmission system for coupling the intermediate member to the drive member for movement in the direction of the optic axis to thereby transmit the rotation of the drive member to the intermediate member irrespective of the movement of the intermediate member in the direction of the optic axis, and a change-over device operable to connect and disconnect the rotation of the manual operator and the intermediate member.
摘要:
In a zoom lens a zoom operating ring is rotatable to vary the focal length of an optical system between a first focal length and a second focal length. A distance ring is rotatable to effect focusing of the optical system with respect to an object to be photographed which is positioned in a normal photographing distance range including infinity. A macro operating ring is rotatable to effect focusing of the optical system with respect to an object to be photographed which is positioned in a macro photographing distance range including an area of a shorter distance than a close distance in the normal photographing distance range. The optical system has a maximum magnification when the focal length is equal to the first focal length. In response to rotation of the macro operating ring, the zoom operating ring is rotated when the focal length of the optical system is equal to a given focal length different from the first focal length and the macro operating ring is in a position of rotation corresponding to a shortest distance within the macro photographing distance range conforming to the given focal length.
摘要:
A DC motor control system which has means for detecting the rise and fall of a drive command signal to generate an ON ACCELERATION/DECELERATION signal and means for generating a current limit signal for driving a DC motor by the ON ACCELERATION/DECELERATION signal to produce a rated output and for driving the DC motor to produce an output 1/n times the rated output when the DC motor is switched from an acceleration state to a stationary state. When the DC motor is accelerated or decelerated by the drive command signal, a current for obtaining the rated output is applied to the armature of the DC motor and, in the stationary state, even when a load on the DC motor is maximum a current for obtaining an output 1/n times the rated output is applied to the armature of the DC motor to reduce the output of the large-output DC motor, thereby providing an enlarged constant output DC motor range.
摘要:
A system for a DC motor associated with a field winding and driven by using a three-phase anti-parallel thyristor bridge circuit, comprising a first means for controlling an armature current I.sub.a flowing through an armature of the DC motor, and; a second means for controlling a field current I.sub.f flowing the field winding by obtaining the feedback values of a voltage E.sub.a of the armature and the field current I.sub.f and by changing the maximum level of the current I.sub.f in accordance with a three-phase alternating voltage V.sub.ac applied to the three-phase anti-parallel thyristor bridge circuit. In the system, when the three-phase alternating voltage V.sub.ac decreases to a value lower than a predetermined value V.sub.o, the field current I.sub.f are decreased so that the armature voltage E.sub.a is decreased.
摘要:
A porous carbon that has an extremely high specific surface area while being crystalline, and a method of manufacturing the porous carbon are provided. A porous carbon has mesopores 4 and a carbonaceous wall 3 constituting an outer wall of the mesopores 4, wherein the carbonaceous wall 3 has a portion forming a layered structure. The porous carbon is fabricated by mixing a polyamic acid resin 1 as a carbon precursor with magnesium oxide 2 as template particles; heat-treating the mixture in a nitrogen atmosphere at 1000° C. for 1 hour to cause the polyamic acid resin to undergo heat decomposition; washing the resultant sample with a sulfuric acid solution at a concentration of 1 mol/L to dissolve MgO away; and heat-treating the noncrystalline porous carbon in a nitrogen atmosphere at 2500° C.
摘要:
A purification method for a carbon material containing carbon nanotubes is provided, which satisfies the following requirements: The method should prevent carbon nanotubes from being damaged, broken or flocculated; the method should be capable of removing the catalyst metal and carbon components other than the carbon nanotubes; and the method should be applicable to not only multi-walled carbon nanotubes but also single-walled carbon nanotubes which will undergo significant structural changes when heated to 1400° C. or higher temperatures. The method is characterized by including a carbon material preparation process for preparing a carbon material containing carbon nanotubes by an arc discharge method, using an anode made of a material containing at least carbon and a catalyst metal; and a halogen treatment process for bringing the carbon material into contact with a gas containing a halogen and/or halogen compound.
摘要:
A carbon fiber reinforced carbon composite, obtained by a method comprising impregnating a pitch or a resin into a molded member formed of carbon fibers for densification thereof; forming an impregnated pyrolytic carbon layer by CVI after densification; and forming a coated pyrolytic carbon layer on the impregnated pyrolytic carbon layer by CVD; a method of making the carbon fiber reinforced carbon composite; and a pulling single crystal member made from the carbon fiber reinforced carbon composite.
摘要:
A heat-resistant adhesive is provided for use in an adhesive member for the fabrication of a semiconductor package by bonding a semiconductor chip to a lead frame with the adhesive member and sealing at least the semiconductor chip and a bonded part between the semiconductor chip and the lead frame with a sealant. The adhesive has a coming-out length of not more than 2 mm and a water absorption rate of not more than 3 wt. %. Preferably, the adhesive has a glass transition point of at least 200° C.
摘要:
A device for detecting opposite phases and an open phase in an input three-phase voltage for a DC motor, wherein the input three-phase voltage is rectified by a three-phase bridge circuit and supplied to the armature of the DC motor. The input three-phase voltage is supplied to the three-phase bridge circuit when the maximum level is equal to or less than the reference voltage, while the input three-phase voltage is not supplied to the bridge circuit when the maximum level is greater than the reference voltage. In this case, both opposite phases and an open phase can be detected by using a common device. In addition, only two phases, such as U- and W-phases, are used for detecting opposite phases and an open phase no matter how these phases may be generated in any phase such as U-, V- or W-phase of the input three-phase voltage. As a result, the device is small in size, simple in electrical construction and low in cost.
摘要:
The invention provides an anode material for lithium ion secondary battery using a coated graphite powder as a raw material, which is coated thermoplastic resin of a carbonization yield of ≦20 wt % in a proportion of ≦10 parts by weight the carbonized material per 100 parts by weight graphite powder. Coating with thermoplastic resin increases the accumulative pore volume by ≦5%, relative to the uncoated powder, and results in pore sizes of 0.012-40 μm via mercury porosimeter method. Calculated with the BJH method as viewed from desorption isotherm, the coated graphite powder has a mesopore volume ≦0.01 cc/g or ≦60% of the pore volume of the uncoated graphite powder. This coated powder also has an average particle size ranging from 10-50 μm measured by a laser-scattering-particle-size-distribution measuring device, and a standard deviation to the average particle size (σ/D) ratio of ≦0.02.