Abstract: The present invention reduces the capacity of the AC-DC converter for the peak load and realizes low price and reduction in the volume of the power unit. The apparatus built-in backup power supply has the peak cut function for sharing a part of the load current at the time of peak load from the secondary battery. The two-way DC-DC converter 5 and the secondary battery 4 are installed on the DC output side of the AC-DC converter 3 and a current larger than a predetermined peak cut level is discharged from the secondary battery 4 at the time of peak load. Further, when the load is less than the predetermined cut level, the secondary battery 4 is charged from the AC-DC converter 3 via the two-way DC-DC converter 5. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.

Abstract: An Automatic Transfer Switch System includes a control circuit in which high frequency transformers, designed to operate linearly in a frequency range above the operating frequency range of utility-level power, are employed for voltage sensing. An output signal from a high frequency line matching transformer is received by a microprocessor which evaluates the signal for both a voltage level and frequency and uses these values as indices to an empirically-derived look-up table which provides an actual voltage level to the microprocessor. The actual voltage value can then be evaluated by the microprocessor to determine if and when the power delivered to a load should be supplied by a first or a second power supply.

Abstract: The invention concerns an apparatus and a method for modifying a power flux in an electrical transmission line section (6,8), each section including phase lines having n conductors (10,12) electrically insulated from one another and shorted at the ends (40) of the section. The apparatus comprises a power exchange unit including a power converter (18) for power conversion between first and second pairs of terminals (20,22), the first pair of terminals (20) being connected in series to at least one conductor of the section; and an electrical element (24) connected to the second pair of terminals (22) and adapted to circulate power through the power converter to modify said power flux.

Abstract: A method is disclosed to add functionality to a terminal of a high voltage integrated circuit without the penalty of additional high voltage circuitry. The benefit is that alternative modes of operation can be selected for testing, trimming parameters of the integrated circuit, or any other purpose without the cost of an additional terminal. In one embodiment, ordinary low voltage circuitry monitors the voltage on the terminal that normally is exposed to high voltage. The configuration of a simple voltage detector and an ordinary latch allows easy entry into the test and trimming mode when the integrated circuit is not in the intended application, but prohibits entry into the test and trimming mode when the integrated circuit operates in the intended application.

Abstract: Disclosed are a stator for a reciprocating motor and a manufacturing method thereof which are able to simplify assembling processes, to reduce assembling time, and thereby to improve productivity by laminating an inner stator to be a straight line shape and bending to be a cylindrical shape. The stator is fabricated by laminating lamination sheets as a straight line and bending it to be a cylindrical shape, and a mounting band is fixed on inner circumferential surface of the lamination sheets so as to maintain the lamination sheets connected when the lamination sheets are bent to be the cylindrical shape.

Abstract: A solenoid-based propulsion system and methodology comprised of at least one multiple wire coil set solenoid that reversibly receives at least a portion of a magnetic object, wherein the wire coil sets of the solenoid are connected to the energizing control system that controls the alternate energizing of the wire coil sets; the adjustable dwell angle of the energizing; and provides for skip energizing. The electronic format of the energizing control system utilizes an electronic timer to establish the frequency at which the alternate energization occurs to propel the magnetic object in a reciprocal motion. The energizing control system in a payload delivery system embodiment of the invention helps converts the kinetic energy stored in the reciprocal motion of the magnetic object into a movement propelling the magnetic object completely and unilaterally out of the invention.

Abstract: The motor assembly which produces an oscillating action for a personal care device includes a horizontally positioned U-shaped stator portion, and an armature portion which includes a torsion spring shaft which is anchored at one end thereof. The armature portion also includes a U-shaped magnet mounting member which is fixed near the upper end of the spring shaft, the U-shaped member including two opposing legs which extend along a substantial part of the length of the spring shaft, away therefrom. At the tips of each leg are magnet assemblies, which interact with the stator portion in alternating torsion, to produce a back-and-forth oscillation of the armature and a brushhead or other workpiece attached thereto.

Abstract: The invention relates to a drum drive that delimits an interior space intended for receiving an electromotor for producing a rotating movement of the drum. The electromotor comprises a stator, shell and stator cap. The stator is turnably journalled about the shaft (7), wherein the drive comprises at least one damping device (10) connected to the shaft (7) and to the stator, and extending radially from the shaft in a plane that is essentially at right angles thereto; and wherein the damping device (10) is configured for absorbing forces that strive to rotate the stator about the shaft.

Abstract: An electric motor having a fan and baffle for directing a flow of cooling air through the motor while minimizing generation of noise. The fan has blades which are curved in a direction opposite to the direction of rotation of the fan. The blades are spaced from a hub of the fan thereby forming a clearance region to inhibit air flow shear and turbulence. The baffle has an annular shape with upstream and downstream faces for directing air flow. The downstream face is inclined so that air flowing along its surface has a component of motion in the downstream direction to inhibit separation of flow from the surface. The baffle is received in a casing of the motor with a slip fit.

Abstract: Disclosed is an axial fan motor for air-cooling a heat sink of a heating element and thermally connected to the heat sink. The casing of the axial fan motor is formed of a plurality of laminated metal plates. The plurality of metal plates include a single first metal plate and a plurality of second metal plates. The single first metal plate, which is an outermost layer located at the air exhaust side of the fan, has a peripheral portion, a central portion, and a plurality of arm portions for connecting the peripheral portion and the central portion. A bearing holder for supporting a rotary shaft of the fan is attached to the central portion.

Abstract: Plurality of air gaps are formed in a torus-shaped stator body of the resolver. If a straight line were drawn from a center point of the stator body toward the outside in the radial direction of the stator body and the straight line were rotated 360 degrees about the center point, the straight line would intersect with at least one of an inside air gap and an outside air gap. Therefore, magnetic flux (i.e., noise caused by magnetism) that has penetrated from the outer peripheral surface side of the stator body will always pass through a portion of the stator body that is to the outside in the radial direction of the air gaps, such that a large portion of the magnetic flux is eliminated by the air gaps.

Abstract: An electromagnetic actuator includes a fixed core supported by a bottom wall of a housing, a movable core arranged opposite to the fixed core via an air gap to drive the movable member, and coil assembly supported by the housing to surround both the cores, wherein the movable member and the movable core are connected by connecting means for adjusting the air gap between the fixed core and the movable core, and wherein an adjustment operating hole through which the connecting means is adjusted is provided on the fixed core so as to be opened outside the bottom wall of the housing. Thus, it is possible to freely adjust the air gap between the fixed core and the movable core without preparing several types of connecting members.

Abstract: A driver IC and passive parts, which convert a direct current voltage into a three-phase voltage, and an FP coil for cyclically generating a magnetic field through the driver IC are mounted on a flexible substrate, which constitutes a small vibration motor. The driver IC is a so-called bare chip in which a circuit section is exposed and is not molded with resin and the like. Magnets and an unbalance weight are installed on a yoke having a shaft. The FP coil and the magnet are placed so as to face each other. A cover is caulked to fixed to a bottom plate. Thus, the vibration motor can be miniaturized and thinned. Moreover, the vibration motor can be automatically manufactured, and installing them to an electronic apparatus can be automatically performed.

Abstract: Disclosed is a brushless vibration motor having a driving circuit therein, which is capable of operating like a typical DC motor. The brushless vibration motor having an eccentric rotor R having an eccentric weight 5b, a rotor case 5 and a magnet 6 which has a plurality of magnetic poles arranged in the rotor case; a shaft 2 for supporting the eccentric rotor, a housing H for supporting the shaft, a stator S which is disposed around the shaft on a stator base 1 constructing a part of the housing and which consists of armature coils to drive the rotor, and a driving circuit member lC which is mounted in a space K corresponding to an area of at least one armature coil.

Abstract: Disclosed is a coin type vibrating motor including: a rotor provided with an upper base including at least one wound coil placed on the upper surface thereof; a stator including a pair of brushes placed on the upper surface of a lower base, on which a magnet is mounted corresponding to the wound coil; and a shafting unit including a bearing member formed integrally with the upper base to surround the wound coil and the weight, and a shaft, of which the bearing member is installed on the outer periphery, wherein an oil scattering-preventing portion, which exposes an assembling region, and has an inner surface extended downwardly to a designated length while being spaced from the inner surface of the shaft, is formed integrally with the lower surface of an insulator exposed to the outside through an opening of the upper base.

Abstract: A motor includes a stator formed of a stack of silicon steel sheet members and a winding holder mounted inside the stack of silicon steel sheet members, axles inserted through the stator in four corners, front and back covers respectively covered on the front and back sides of the stator and engaged with the ends of the axles and affixed to the stator with screws, and a rotor supported between the front and back covers and suspending within the stator.

Abstract: An axial gap electrical machine employs unique architecture to (1) overcome critical limits in the air gap at high speeds, while maintaining high torque performance at low speeds, while synergistically providing a geometry that withstands meets critical force concentration within these machines, (2) provides arrangements for cooling said machines using either a Pelletier effect or air fins, (3) “windings” that are produced as ribbon or stampings or laminates, that may be in some cases be arranged to optimize conductor and magnetic core density within the machine. Arrangements are also proposed for mounting the machines as wheels of a vehicle, to provide ease of removing and installing said motor.

Abstract: A spoke permanent magnet rotor that includes a shaft defining a rotor axis. A first non-magnetic end portion is coupled to the shaft and a ferromagnetic pole piece defines an aperture therethrough. A second non-magnetic end portion is positioned to dispose the pole piece between the first end portion and the second end portion. A portion of one of the first end portion and the second end portion extends through the aperture and bonds with the other of the first end portion and the second end portion.

Abstract: In a fuel pump, four permanent magnets are installed in a housing. An armature is installed inside the permanent magnets rotatably. Six magnetic pole coil portions of the armature are installed in a central core. Each magnetic pole coil portion has a coil core, a bobbin and a coil formed by winding a winding on the bobbin in a concentrated winding form. Each coil core has an outer region in opposition to the permanent magnet in a direction of revolution, and a board-shaped coil-winding portion extending from the outer region toward the central core. Each bobbin covers the coil core except for the outer surface of the outer region and a convex portion.

Abstract: The present invention is related to a permanent magnet electrical generator/motor comprising a stator, a rotor, a rotational axis and an air gap between stator and rotor so that the magnetic flux across said air gap is essentially oriented along said rotational axis, said rotor preferably comprising a plurality of permanent magnets to form rotor poles, said generator/motor being characterised in that said stator comprises a disc (1), and a plurality of magnetic cores (2), said cores (2) being attached to said disc (1) by attachment means, said cores comprising coils (6) wound round the legs of said cores. Furthermore, said machine comprises means for distributing the flux across the air gap between rotor and stator. Preferably, this takes on the form of flux distribution plates (28,29), placed between rotor and stator.

Abstract: The present invention combines bending mode mechanical (frm) and electrical (fre) resonances, whereby a relatively good efficiency can be achieved within a relatively broad frequency range (?f3). An electrical resonance (frc) or mechanical resonance is designed to be situated in the same order of magnitude as another mechanical resonance (frm), but separated therefrom. Preferably, the separation (?f2) is smaller than 2f1/Q1, where f1 is the resonance frequency for the resonance having lowest quality value, and Q1 is the corresponding quality value of the mechanical resonance. An electromechanical motor comprising a driving element and electrical resonance circuit according to the above ideas may comprise a double bimorph driving element having one single actuating point influencing a body to be moved. The double bimorph driving element is excited in bending vibrations perpendicular to a main displacement direction, whereby both tangential and perpendicular motions are created by bending mode vibrations.

Abstract: A motor includes a resonator and a vibration source coupled to the resonator. The vibration source can be a piezoelectric vibration source. A drive shaft is coupled to the resonator via a linkage. The vibration source(s) impart a vibration along the resonator such that a lateral displacement of the resonator is focused at a location coupled to the linkage. The lateral displacement is coupled to the drive shaft to provide rotational motion of the drive shaft.

Abstract: A vibration wave linear motor comprises a vibrator unit having two driving contacting parts which are respectively formed on top and bottom surfaces of the vibrator unit, two guide members guiding the running of the vibrator unit by sandwiching the vibrator unit in parallel with the running direction. The upper guide member is fixed to the supporting member. The lower guide member is held in shaft bearing long holes, pressed upward by coil springs within hollow convex parts. The vibrator unit self-runs and moves forward and backward between the two guide members with an ultrasonic vibration. A linking pin fixed on the side surface of the vibrator unit engages with the member to be driven, so that moving force is transmitted.

Abstract: A tool has a tool insert and an electrically operated drive unit oscillatingly driving the tool insert. The drive unit has a piezo actuator and an adjusting travel enlarger coupled to the piezo actuator. The adjusting travel enlarger has a master piston, at least one slave piston, and at least one pressure chamber. The master piston acts through the at least one pressure chamber on the at least one slave piston. The piezo actuator and the master piston are fixedly connected to one another.

Abstract: A rotation/displacement converting actuator has an actuator unit constituted by a displacing body and an actuator in which the displacing body can be linearly displaced. The actuator has a pair of plate-shaped bases, a rotor, a vibrating element that rotates the rotor, and a cam mechanism for converting rotary motion of the rotor to linear motion of the displacing body. The rotor is fixed to a shaft to which the rotor (cam rotor) is fixed. An outer circumferential surface of the rotor constitutes a cam surface of the cam mechanism. A roller is provided at a tip portion of the displacing body. The roller abuts on the outer circumferential surface (cam surface) of the rotor.

Abstract: An oscillating-type generator is provided in which an impact member impacts piezoelectric elements to generate electricity and which can efficiently increase the number of impacts and generate a large amount of electricity. This oscillating-type generator includes: a generator member 2 having an impact member 22 impacting piezoelectric elements 21 to generate electricity; and an elastic member 4 having elasticity, attached to the generator member 2 and, when applied an external force, adapted to oscillate the generator member 2 to cause the impact member 22 to repeat impacting the piezoelectric elements 21.

Abstract: A piezoelectric device including an IC chip mounted on an inner bottom surface of a package, and a piezoelectric vibrating reed electrically and mechanically connected onto a TAB tape in which a lead is provided on a surface of a resin tape. The TAB tape to which the piezoelectric vibrating reed has been joined is mounted in the package, whereby the piezoelectric vibrating reed is arranged above the IC chip.

Abstract: A piezoelectric actuator including two or more piezoelectric layers each of which is formed of a piezoelectric material and which are stacked on each other; three or more electrode layers which are stacked alternately with the piezoelectric layers; and one or more active portions each of which includes respective portions of the piezoelectric layers that are sandwiched by the electrode layers in a direction of stacking of the piezoelectric layers. Each active portion is expanded and contracted when an electric voltage is applied to the electrode layers. The piezoelectric layers include one or more first piezoelectric layers each having a first thickness, and one or more second piezoelectric layers each having a second thickness greater than the first thickness.

Abstract: The present invention provides arrangements for electroluminescent displays 10 comprising a packaged semiconductor light emitting element 12 that has a light emitting display side 16. A heat sink 22 is disposed in the region of a rear side of the light-emitting element 12 opposite to the display side. Electrical connections 28 from the light emitting element 12 pass through said heat sink 22. Drive circuitry 30 for the light emitting element 12 is connected thereto by the electrical connections 28 and spaced apart from the heat sink 22 in such a manner that at least one cooling channel 34 is defined between the heat sink 22 and the drive circuitry 30 for the passage in use of a cooling fluid.

Abstract: A LED package including an LED that emits excitation light at an excitation light wavelength and a layer of phosphor material positioned to receive the excitation light and having a first index of refraction at the excitation light wavelength. The phosphor material emits visible light at a visible light wavelength when illuminated with the excitation light. An interference reflector is positioned adjacent to the layer of phosphor material and a TIR promoting layer is in contact with the layer of phosphor material. The TIR promoting layer has a second index of refraction at the excitation light wavelength that is less than the first index of refraction at the excitation light wavelength.

Abstract: An illuminating device is made from a transparent hollow envelope that encloses a filler gas. The envelope has inner and outer surfaces. The illuminating device has a coating of a fluorescent material deposited on the inner surface of the transparent envelope where the fluorescent material emits light having a visible component and an ultraviolet component; and a titanium dioxide film having first and second opposing surfaces where the first surface of the titanium dioxide film is formed on the outer surface of the transparent envelope. A light transmittance of the titanium dioxide film is at least 50% for light having a wavelength of 550 nm, and the light transmitted from the fluorescent material through the transparent envelope and the first surface of the titanium dioxide film to the second surface thereof causes photocatalytic activity to be generated on the second surface of the titanium dioxide film.

Abstract: An electron tube includes a vessel, a primary linear member installed in the vessel, an electrode disposed in the vessel, a first auxiliary linear member and a second auxiliary linear member disposed at different heights to interpose the primary linear member therebetween, and a plurality of fixing members. The fixing members are formed at a single substrate for constituting a part of the vessel, for fixing end portions of the first auxiliary and the second auxiliary linear member thereto.

Abstract: Ribs for an image display medium, which ribs can be retained between a pair of substrates. These image display medium ribs are formed by liquid injection molding (LIM molding), utilizing a heat-curable epoxy resin. In addition, the image display medium ribs are formed so as to have a cell-form arrangement.

Abstract: A transfer film comprising a base film (11), a parting-agent layer (12), a protective film (13), and a metal film (14), the latter three being formed on the base film (11) in order, wherein the protective film (13) contains a softening agent such as a phosphate, an aliphatic monobasic acid ester, an aliphatic dibasic acid ester, or a dihydric alcohol ester. By using such a transfer film, a metal back layer is formed. Since the transfer layer of the transfer film has a surface resistivity of as high as 102–108 ?/, the surface resistivity of the formed metal back layer is high, and discharge is suppressed.

Abstract: In a projection cathode ray tube device in which a projection cathode ray tube and a projection lens assembly are coupled and held by a coupler, superior focus characteristics and high resolution are realized by eliminating the deviation between the center of the phosphor screen of the cathode ray tube and the center of the lens assembly. In the cathode ray tube, each of the outside and inside surfaces of a faceplate is formed as a spherical convex surface which is curved toward an electron gun.

Abstract: A single-component, yellow-emitting electroluminescent phosphor, a method for making same, and an electroluminescent lamp containing same, are described. The phosphor produces a yellow emission having an x color coordinate from 0.420 to 0.500 and y color coordinate from 0.420 to 0.460 when stimulated by an electric field.

Abstract: A blink plasma backlight system for a liquid crystal display comprises a first substrate; a second substrate arranged substantially in parallel with and spaced-apart from the first substrate, forming a gas discharge space therebetween; at least one electrode pair disposed on an inner surface of the second substrate, the electrode pair containing a first electrode and a second electrode approximately parallel to each other; a control unit coupled to the electrode pair, for periodically providing an energy to ignite a gas discharge between the first and second substrates; a dielectric layer disposed on the inner surface of the second substrate covering the electrode pairs; and a first fluorescent layer disposed on the inner surface of the first substrate.

Abstract: A self-luminescence display device, in which dispersion in display among a plurality of pixels, caused by dispersion in characteristics among drive thin-film transistors, is decreased and uniform display free of unevenness can be obtained. The device includes a plurality of pixels having current drive type luminescent elements, and parallel-connected n (n?2) thin-film transistors to feed a drive current to the respective current drive type luminescent elements. The transistors are arranged in different pixels, respectively, for example, in a first region of pixels adjacent to one another along a first direction. A second region of dummy pixels can be provided on at least one side of said first region along said first direction.

Abstract: A field emission device for use as a backlight of a liquid crystal display comprises a conductive anode having a light-emitting layer and a cathode separated from the anode by a spacer. The cathode comprises nanofiber electron emitters. For example, the nanofiber electron emitters comprise a substrate, a conductive film adhered to the substrate and a plurality of isolated, hemispheroidal nanofiber clusters that are capable of emitting electrons at high current density and low field strength.

Abstract: A field emission display device includes: a first substrate; an electron emission assembly arranged on the first substrate; a second substrate arranged a predetermined distance from the first substrate, the first and second substrates forming a vacuum space; an illumination assembly arranged on the second substrate, the illumination assembly being illuminated by electrons emitted from the electron emission assembly; and a mesh grid and above the electron emission assembly.

Abstract: An image formation apparatus is disclosed which includes, within an enclosure configured by a pair of substrates placed face to face and an external frame placed between the substrates, an electron source placed on one of the pair of substrates, an image formation material placed on the other substrate, and spacers placed between the substrates, characterized in that the spacers and the external frame is conductive and device is provided for electrically connecting the spacers and the external frame so that the equipotential surfaces between the spacers and the external frame are quasi-parallel when driven.

Abstract: A self-charging organic electroluminescent display is disclosed. A solar cell and an organic electroluminescent device are installed on a same substrate or different substrates. Using the photoelectric conversion property of the solar cell, the solar energy is converted into electrical energy and stored in a battery. Therefore, the electrical energy converted from the solar energy can be provided for the organic electroluminescent device to emit light, forming a self-charging organic electroluminescent display module.

Abstract: A front emitting or a dual-side emitting organic electroluminescent display device which has uniform luminance. The organic electroluminescent display device includes a substrate on which a first electrode for defining at least a portion of a pixel region is formed. An organic film layer including an emitting layer is formed on the substrate, and a second electrode including a first semi-transmissive type metal layer is formed on the organic film layer. A first transmissive type conductive oxide layer is formed on the first semi-transmissive type metal layer. A second semi-transmissive type metal layer is formed on the first transmissive type conductive oxide layer, and the second transmissive type conductive oxide layer is formed on the second semi-transmissive type metal layer.

Abstract: A light emitting diode including an element substrate, a light emitting element mounted on said element substrate, a sealing body which transmits and emits light from the light emitting element and which seals the light emitting element, and a light shielding member to form light emitting parts for directing light from the sealing body in two dimensional directions which are formed from a combination of two axes of three dimensional axes X, Y and Z, has the light shielding member configured to cause one portion of the light emitting parts to emit light and the other of the light emitting parts to shield light.

Abstract: There is disclosed a gas discharge plasma display device comprising one or more ionizable gas filled elongated tubes. In one embodiment, the device is operated as a positive column gas discharge display. In another embodiment, the display is a monolithic or single substrate display.

Abstract: A plasma display panel comprises: a plurality of substrate having a front substrate and a back substrate disposed opposite to each other; dielectric walls disposed between a front surface and a back surface, and defining discharge cells in cooperation with the front substrate and the back substrate; a plurality of discharge electrodes separately disposed around the discharge cells and buried into the dielectric walls; dummy electrodes formed at outer portions of the discharge electrodes disposed in one direction of the substrate and etched when over-etching takes place during the time of developing; and red, green and blue color fluorescent layers coated within the discharge cells.

Abstract: The present invention relates to a headlight lamp (110) having a multifunction structure in which a lighting angle of a headlight of a vehicle is automatically and manually controlled based on a running speed of a vehicle, a brightness of a headlight of an opponent vehicle and a surrounding brightness of a vehicle. The headlight lamp (110) includes a plurality of high angle headlight filaments (115), capable of lighting for providing a high angle beam to a vehicle, a plurality of low angle headlight filaments (111) capable of lighting for providing a low angle beam to the vehicle, low angle headlight reflection covers (112) provided in the low angle headlight filaments (111) respectively, for thereby allowing the light from the low angle headlight filaments (111) to have a low beam pattern angle, and external connection terminals.

Abstract: An approach for stabilizing the interactions between a plasma and the generator powering the plasma is provided. Reactive elements disposed between the power generator and plasma operate to modify the apparent impedance characteristics of the plasma such that the trajectory of the plasma load impedance as a function of power is substantially aligned locally with the contours of constant power output in impedance space. In this way, instabilities in the generator and plasma system are avoided because reinforcement or amplification of fluctuations in plasma impedance due to interactions between the generator and the plasma are reduced or eliminated. The reactive elements may be variable in order to align plasma trajectories and generator power contours under a range of process conditions.

Abstract: In a detection mode, a reverse bias voltage VM is applied to any one of scan lines K1–Km arranged in a light emitting display panel 1. The electrical potentials generated at respective data lines A1–An of this time are supplied to potential determination means J1–Jn. In the potential determination means J1–Jn, the electrical potentials generated at the respective data lines A1–An are supplied to switching elements Q31–Q3n via transfer switches Q11–Q1n. When the electrical potentials are the threshold voltages of the switching elements Q31–Q3n or greater, the outputs of comparators CP1–CPn are inverted, and the states of this time are latched in latch circuits LC1–LCn to be stored in a data register 11. By data stored in the data register 11, it is determined whether or not a defect has occurred in pixels of the display panel, and the location thereof is also determined.

Abstract: First resistors (R1, R2) for setting a forward current value are connected in series to light-emitting diodes (LED 1, LED 2) respectively to constitute first serial circuits (112, 113), which are connected to an input terminal (111). Second serial circuits (115, 116) are connected in parallel to the first serial circuits (112, 113) respectively. The second serial circuits (115, 116) are constituted by a combination of a Zener diode (ZD1) and a second resistor (R3), and another combination of a Zener diode (ZD2) and a second resistor (R4). When a higher voltage than rated voltages of the light-emitting diodes (LED 1, LED 2) is applied, the Zener diodes (ZD1, ZD2) shunt current into the second serial circuit (115, 116) to allow the light-emitting diodes (LED 1, LED 2) to light up at desirable luminance levels different from each other.