Abstract: An optical zoom lens module includes, in this order from the object side to the image side thereof, a first lens group of positive refraction power, a second lens group of negative refraction power, a third lens group of positive refraction power, and a fourth lens group of positive refraction power. The optical zoom lens module satisfies the formula: 12<TTL/FW<16, and 6<F1/F<8, where TTL is the total length of the optical zoom lens module, FW is the smallest effective focal length of the optical zoom lens module, F1 is the effective focal length of the first lens group, and F is the effective focal length of the optical zoom lens module.

Abstract: The present invention provides an imaging lens assembly, comprising in order from an object side toward an image side, a first lens element with positive refractive power having a convex object-side surface, a second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and an aperture stop positioned between an imaged object and the first lens element. The above lens arrangement shortens the total track length effectively, enabling a high performance imaging lens assembly with a wide field of view.

Abstract: Disclosed is an image pickup lens (LN) including at least three lens blocks (BK) each equipped with a lens substrate (LS) being a parallel flat plate, and a lens or lenses (L) having a positive or negative power and being connected to at least one of an object-side surface and an image-side surface of the lens substrate (LS). In the image pickup lens (LN), a first lens block (BK1) arranged at a closest position to an object side has a positive powder, a second lens block (BK2) arranged at an image side of the first lens block (BK1) has s negative power, and predetermined conditional expressions are satisfied, whereby the image pickup lens capable of being easily produced at a low cost and having a high performance and a compact size can be provided.

Abstract: A wide-angle projection optical system includes a first lens set with positive power, an aperture stop, a second lens set with positive power, a third lens set with negative power, and a negative power reflecting mirror. The first lens set provides optical characteristics to match with a light beam coming from the object side. The second lens set is arranged behind the aperture stop to converge the light beam. The third lens set is configured to diverge the light to enlarge a full field angle. The negative power reflecting mirror is configured to further enlarge the full field angle and correct image distortion. The first lens set, the second lens set, the third lens set and the reflecting mirror have a common optical axis. The optical axis is shifted with respect to a center of a micro display.

Abstract: The present disclosure relates to a projection lens. The projection lens includes, in order from the magnified end to the minified end thereof, a first lens of negative refraction power, a second lens of positive refraction power, a third lens of negative refraction power, a fourth lens of positive refraction power, and a fifth lens of positive refraction power. The forth lens and the third lens are bonded to integrally form a compound lens of negative refraction power. The projection lens satisfies the following condition: 0.4<R12/f<0.9. Wherein, R12 is a radius of curvature of the surface at the minified end of the first lens, f is an effective focal length of the projection lens.

Abstract: The present invention relates to an optical part holding member made of ceramic and a production method thereof, and provides an optical part holding member made of ceramic such that a sintered body after processes of degreasing and sintering has small dimensional changes over dimensions of a mold, and a production method thereof. An example includes a lens holder to hold an optical part, made of a silicon nitride ceramic base composite material produced through a process in which silicon and nitrogen are reacted to be nitrided and contains silicon carbide and an iron compound.

Abstract: The present invention relates to an optical part holding member made of ceramic and a production method thereof, and provides an effective permeability to prevent dew condensation. The optical part holding member is made of a silicon nitride ceramic base composite material to hold an optical part, which is produced through a process of nitriding in which silicon is caused to react with nitrogen. By using the silicon nitride ceramic base composite material containing silicon carbide and an iron compound, an airflow volume of 50 ml or more per minute is achieved in an effective airflow area of 1.5 cm2 when an air pressure is added with a pressure difference of 0.4 MPa between both surfaces of a sample of the silicon nitride ceramic base composite material having 1 mm thickness, and the optical part holding member having effective permeability to prevent dew condensation is obtained.

Abstract: An external lens device is mounted in front of a lens of an image pickup device. The external lens device includes a fixer and an external lens. The fixer includes a fixing slot and an alignment slice. The alignment slice includes a first reference mark and a second reference mark. The first reference mark is enclosed by the second reference mark. The first reference mark is arranged in the middle portion of the second reference mark. After the fixer is placed in front of the image pickup device, an outer portion of the second reference mark of the alignment slice is parallel with the lens fastening part of the lens of the image pickup device, the first reference mark is aligned with a center of the lens of the image pickup device, and the second reference mark is concentric with a lens fastening part of the lens.

Abstract: Provided is a lens driving device reduced in sizes. In a right side region divided by a virtual center line vertically passing the outer circumference region of both lens group holding frames, including an optical axis, a lens driving device concentratedly has a first guide pole, a second guide pole, a lead screw of a first piezoelectric motor, and a lead screw of a second piezoelectric motor, when viewed from the front. Furthermore, the lead screw of the first piezoelectric motor and the lead screw of the second piezoelectric motor are arranged in an intermediate region between the first guide pole and the second guide pole.

Abstract: An optical apparatus includes a lens barrel, an optical apparatus body, a body-side mounting unit, a lens-side mounting unit arid a position determination mechanism. A plurality of projection pins protrude from an outer circumferential surface of a cylindrical part of the body-side mounting unit. A groove is formed in an inner circumferential surface of the lens-side mounting unit. Cutout regions that are in communication with the groove are formed in a surface of the lens-side mounting unit that faces toward a flange part of the body-side mounting unit at positions that respectively correspond to positions of the projection pins. The position determination mechanism determines a position of the lens-side mounting unit around the optical axis of the optical apparatus body.

Abstract: An exterior rearview mirror assembly for a motor vehicle includes a housing defining an interior and including a mirror opening oriented rearward when the exterior rearview mirror assembly is secured to the motor vehicle. A backing plate is operatively connected to the housing in the interior. The backing plate is selectively moveable within the housing. A primary mirror is fixedly secured to a first portion of the backing plate. A secondary mirror is fixedly secured to a second portion of the backing plate. The secondary mirror is spaced apart from the primary mirror. An adhesive member extends between the backing plate and the primary and secondary mirrors such that the single adhesive member secures all of the primary and secondary mirrors to the backing plate. A demarcation divider separates the primary and secondary mirrors. The demarcation divider is secured to the backing plate.

Abstract: This invention relates to a dispersant for an organic pigment comprising a compound represented by the below-described formula (1) or (2), and also to its use. According to the present invention, it is possible to provide a dispersant or the like, which can afford a coating formulation for a color filter. The coating formulation is prevented from an increase in viscosity and a reduction in storage stability even when the concentration of a pigment is high, and can fabricate the color filter with excellent transparency and color quality.

Abstract: A color filter array includes a die region having at least a die corner defined therein, a plurality of color filters arranged in a matrix in the die region, and at least a step-shaped corner positioned corresponding to the die corner.

Abstract: A TAMR (Thermal Assisted Magnetic Recording) write head uses the energy of optical-laser generated plasmons in a plasmon antenna to locally heat a magnetic recording medium and reduce its coercivity and magnetic anisotropy. To enable the TAMR head to operate most effectively, the maximum gradient of the magnetic recording field should be concentrated in the small region being heated. Typically this does not occur because the spot being heated by the antenna is offset from the position at which the magnetic pole concentrates its magnetic field. The present invention incorporates a magnetic core within a plasmon antenna, so the antenna effectively becomes an extension of the magnetic pole and produces a magnetic field whose maximum gradient overlaps the region being heated by edge plasmons being generated in a conducting layer surrounding the antenna's magnetic core.

Abstract: A waveguide is provided, in which the optical coupling efficiency to a light source is sufficiently high, and the light-emitting spot center is stably provided at the intended position. The waveguide comprises a multilayered structure in which refractive indexes of layers having a surface contact with each other are different from each other. The multilayered structure is divided into a plurality of groups, and the length from the light-receiving end surface to the light-emitting end surface of one group is different from that of the neighboring group, and the protruded light-emitting end surface of the first group defined as a group that has the largest length includes a center of the light-emitting spot. In this waveguide, the state in which the light-emitting spot center is positioned within the light-emitting end surface does not easily be changed, even when the light-receiving spot center within the light-receiving end surface is rather displaced.

Abstract: A control device includes an acquisition section which acquires a reading signal from a head under plural heat amounts, an computation section which computes plural kinds of characteristic values representing characteristics of the reading signal for each of the plural generated heat amounts by using at least one kind of algorithm, a contact determination section which determines whether or not the head contacts the storage medium for each of the two or more kinds of characteristic values based on a change of the characteristic values for the generated heat amount, and an association determination section which determines an association of a distance between the head and the storage medium with the generated heat amount when determined that the head contacts the storage medium for any of the characteristic values as the generated heat amount when the head contacts the storage medium so that the is considered to be zero.

Abstract: The objective of this invention is to provide a motor control device, and a disk drive device using the same, in which during emergency operation it is possible to supply necessary power to the motor while limiting enlargement of the circuit area. During the retraction operation, control is performed to alternate between a short-circuit mode in which each terminal U, V, W of the spindle motor Ml is short-circuited to the terminal ICOM, and a rectifying mode in which the back electromotive force of the spindle motor M1 is rectifies and output to the power supply line ISO3V, VGND while the input of power from the power supply line ISO3V, VGND to the spindle motor M1 is blocked.

Abstract: A method to adjust the orientation of a read head comprising a first read element and a second read element, wherein the first read element and the second read element are separated by a distance, wherein the method moves a sequential information storage medium adjacent to the read head, determines a skew angle for the sequential information storage medium with respect to the read head using the first read element and the second read element, and encodes that skew angle in a computer readable medium.

Abstract: A method is presented to rotate a read/write head rotatable along a first axis and comprising a first assembly having a first servo element and a second servo element. The method moves a sequential information storage medium adjacent to the read/write head along a second axis, wherein the second axis is substantially orthogonal to the first axis, and determines the rotation angle for the read/write head with respect to the sequential information storage medium using the first servo element and the second servo element. The method then positions the read/write head with respect to the second axis based upon the rotation angle.

Abstract: A perpendicular magnetic write head capable of suppressing damage and corrosion of a magnetic pole to secure a stable writing performance is provided. A non-magnetic protruding layer protruding from a main magnetic pole layer (tip portion) toward an air bearing surface side is formed on both sides of the tip portion in a writing track width direction. The non-magnetic protruding layer is located closer to a recording medium than the tip portion during writing operation, and more likely to be in contact with the writing medium instead of the tip portion. Since the portion of the protective film covering the tip portion hardly peels off while the portion of the protective film covering the non-magnetic protruding layer is easy to peel off, the tip portion is hardly damaged or corroded. Since the tip portion is protected physically and chemically by the non-magnetic protruding layer, the deterioration of the soft magnetic characteristics of the tip portion is suppressed.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling both a radial dynamic pressure groove array and a pumping groove array to have a sufficient axial dimension. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion, so that any air bubbles introduced into a lubricating oil by the pumping groove array can be efficiently caused to flow downward through the through hole and out of the bearing apparatus.

Abstract: A substrate for a magnetic read/write head is disclosed. The substrate can reduce detachment of crystal grains when unexpected vibrations or impacts are applied. The substrate may be machined when the substrate is cut into strips or a flow path surface recess is formed to produce the magnetic read/write head. The reduced detachment of crystal grains makes the magnetic read/write head more resilient to chipping, which allows the magnetic read/write head to have good performance in read/write.

Abstract: A head gimbal assembly for use with a load beam includes a gimbal, a slider for carrying a transducing head, and first and second tabs. The gimbal is configured to be supported by the load beam, and includes a gimbal tongue. At least a portion of the slider is secured to the gimbal tongue. The first tab extends from the gimbal tongue proximate a first corner of the slider. The second tab is spaced from the first tab and extends from the gimbal tongue proximate a second corner of the slider.

Abstract: A head gimbal assembly includes a gimbal, a slider, and a polymer layer. The gimbal comprises a metal layer, and the metal layer of the gimbal defines a gimbal mounting portion for attachment to a metallic load beam and a gimbal tongue extending from the gimbal mounting portion. The slider comprises a ceramic material for carrying a transducing head, and at least a portion of the slider is secured to the gimbal tongue. The polymer layer is positioned adjacent to the gimbal and configured for limiting ceramic-to-metal and metal-to-metal contact.

Abstract: According to one embodiment, a head gimbal assembly includes: base plate body; flexure; through hole passing through the base plate body; cylindrical base that upstands from the front surface of the base plate body, and has a first inner diameter; a cylindrical flange that continues to the base around the through hole and has a second inner diameter smaller than the first inner diameter; and inner wall surface that is defined by the flange and extends along a cylindrical surface formed by a generating line parallel to a central axis of the through hole. A ratio of a thickness T of the flange defined along a virtual plane orthogonal to the central axis of the through hole to a length L of the inner wall surface defined in a direction parallel to the central axis of the through hole is set to 1.5 or less.

Abstract: According to an embodiment, a magnetic head for perpendicular recording, includes a slider including a facing surface opposed to a recording medium, and a head portion on the slider and configured to perform information processing for the recording medium. The head portion includes a main pole configured to apply a perpendicular recording magnetic field to the recording medium, a recording coil configured to excite the main pole, a write shield pole opposing the main pole across a write gap, side shields arranged individually on opposite sides of the main pole in a track width direction and magnetically isolated from the main pole, and low-flux-density layers formed of a material having a saturation magnetic flux density lower than that of the main pole, located between the main pole and the side shields, and configured to regulate magnetic fluxes flowing from the main pole to the side shields.

Abstract: An electro-static-discharge (ESD) protection circuit protects core transistors. An internal node to the gate of an n-channel output transistor connects to the drain of an n-channel gate-grounding transistor to ground. The gate of the gate-grounding transistor is a coupled-gate node that is coupled by an ESD coupling capacitor to the output and to ground by an n-channel disabling transistor and a leaker resistor. The gate of the n-channel disabling transistor is connected to power and disables the ESD protection circuit when powered. An ESD pulse applied to the output is coupled through the ESD coupling capacitor to pulse high the coupled-gate node and turn on the gate-grounding transistor to ground the gate of the n-channel output transistor, which breaks down to shunt ESD current. The ESD pulse is prevented from coupling through a parasitic Miller capacitor of the n-channel output transistor by the gate-grounding transistor.

Abstract: A system for testing a power supply unit includes a test sub-system and a test control sub-system connected to the test sub-system and the power supply unit. The test sub-system perform tests and record the results. The test control sub-system is capable of selecting test items to test the power supply unit and setting an execution sequence of the test items. The test items includes a standby test item for testing the power supply unit at a standby state, a normal test item for testing the power supply unit at a normal state, and an over temperature protection test item for testing the power supply unit at an over heated state. The test control sub-system is further capable of automatically switching the standby test item to the normal test item, and switching the normal test item to the over temperature protection test item.

Abstract: An over-current protection circuit is disclosed that provides a current limit threshold using resistors in the path of a scaled mirror current of a load current. The protective circuit has a first state that passes a supply source to a device, but when the threshold is reached the circuit becomes a feedback circuit that allows only a set final current to be passed to the device. When the load current reaches the threshold, the mirror current reaches a corresponding threshold that triggers a comparator and circuitry that then limits and fold backs the load current.

Abstract: A semiconductor device which combines reliability and the guarantee of electrical characteristics is provided. A power MOSFET and a protection circuit formed over the same semiconductor substrate are provided. The power MOSFET is a trench gate vertical type P-channel MOSFET and the conduction type of the gate electrode is assumed to be P-type. The protection circuit includes a planar gate horizontal type offset P-channel MOSFET and the conduction type of the gate electrode is assumed to be N-type. These gate electrode and gate electrode are formed in separate steps.

Abstract: Connectors for cables such as a 30-pin connector are provided. The connectors may have thermal protection circuits and may carry a power supply voltage and a ground voltage. The thermal protection circuits may disable the power supply voltage when the temperature of the connector exceeds a threshold value. The connectors may have structures that encourage any dendritic failure to occur in a preferred location.

Abstract: A circuit protection device for protecting a photovoltaic (PV) system from an overcurrent condition. The circuit protection device includes a first electrode electrically connectable to a first line of an electrical circuit, a second electrode electrically connectable to a second line of the electrical circuit. A first thermal element, second thermal element and an overload assembly define a first conductive path between the first and second electrodes. A bypass shunt defines a second conductive path between the first and second electrodes. The overload assembly electrically connects the first thermal element to the second thermal element, and is moveable between a closed position and an open position (i.e., overload condition). A low melt temperature solder electrically connects the overload assembly to the second thermal element. The low melt temperature solder softens and melts as the temperature increases in response to an overcurrent condition.

Abstract: The invention discloses a transient voltage detection circuit suitable for an electronic system. The electronic system includes a high voltage line and a low voltage line. The transient voltage detection circuit includes at least one detection circuit and a judge module. Each detection circuit includes a P-typed transistor and/or an N-typed transistor, a capacitor and a detection node. The transistor is coupled with the capacitor, and the detection node is located between the transistor and the capacitor. The judge module is coupled to each of the detection nodes. The judge module generates a judgment according to voltage levels of the detection nodes. Accordingly, the transient voltage detection circuit is formed. The electronic system may selectively execute a protective action according to the judgment.

Abstract: An electronic weapon has an installed deployment unit from which an electrode, tethered by a filament, is launched, according to various aspects of the present invention. The electronic weapon provides a stimulus signal through a target to inhibit locomotion by the target. The electrode includes a body and a spear. The body has an interior. The spear has a tang. During assembly of the electrode, the filament is positioned in the interior. The tang is positioned in the interior over the filament. The tang is then mechanically coupled to the body, securing the filament in the interior. After assembly, applying a force along the filament results in friction between the filament and the interior. The interior of the body may include an undulation.

Abstract: An electronic weapon has an installed deployment unit from which an electrode, tethered by a filament, is launched. According to various aspects of the present invention, the deployment unit includes a housing, two filaments stored in the housing prior to launching, and two electrodes, each coupled to the end of one of the filaments. A propellant in the housing launches the electrodes responsive to the launch device. In operation, an end portion of each filament experiences a tensile stress during launching. The tensile stress follows a nonlinear path along a surface of an undulation of an interior of the respective electrode.

Abstract: An electrical component capable of performing hot switching at low power consumption is disclosed. The electrical component has a first electrical component and a second electrical component connected in parallel to the first electrical component. The first electrical component includes a first electrode and a second electrode facing the first electrode with a space in between, the second electrode is moved by a first actuator portion. The second electrical component includes a third electrode and a fourth electrode facing the third electrode with a space in between, the fourth electrode is moved by a second actuator portion having a stiffness higher than a stiffness of the first actuator portion, the second electrical component has an impedance becoming higher or lower than an impedance of the first electrical component depending on a moving state of the fourth electrode.

Abstract: According to the preferred embodiment, an integrated capacitor having a fence-shaped structure is provided. The integrated capacitor comprises a fence-shaped, outer metal pattern and a dielectric layer. The fence-shaped, outer metal pattern encompasses an inner metal pattern, and the dielectric layer is situated between the outer metal pattern and the inner metal pattern.

Abstract: [Problem to be Solved] To provide a helical capacitor for controlling a high-frequency power which flows in power lines, and a manufacturing method of the helical capacitor. [Solution] A helical capacitor is constituted by helically spiraling a belt shape capacitor line 1001 which includes an internal metal body to be a helically spiraled belt-shape internal electrical conductor, a dielectric film covering the internal electrical conductor, and an electrically conductive layer covering the dielectric film. The capacitor line of belt shape 1001 can be wrapped around the internal support body 1200. Internal metal body lead terminals 1311, 1321 are respectively formed at both ends of the internal metal body, and electrically conductive layer lead terminals 1312, 1322 can be respectively formed at both ends of the electrically conductive layer.

Abstract: Capacitors and methods of forming capacitors are disclosed, and which include an inner conductive metal capacitor electrode and an outer conductive metal capacitor electrode. A capacitor dielectric region is received between the inner and the outer conductive metal capacitor electrodes and has a thickness no greater than 150 Angstroms. Various combinations of materials of thicknesses and relationships relative one another are disclosed which enables and results in the dielectric region having a dielectric constant k of at least 35 yet leakage current no greater than 1×10?7 amps/cm2 at from ?1.1V to +1.1V.

Abstract: At least one wound film/foil or metalized film capacitor is sealed between its electrodes to form a sealed enclosed annular region between the interior of the enclosure, the electrodes and the exterior of the wound capacitor to form a sealed capacitor assembly. A fluid dielectric can be introduced into the sealed enclosed annular region under a vacuum to form a sealed and impregnated wound capacitor assembly.

Abstract: A portable extension memory storage device comprises a body and a slide positioning member. The body includes an elastic positioning tongue. The slide positioning member includes a positioning rib to be engaged into a positioning concave in the positioning tongue. With the elastic positioning tongue, the abrasion can be reduced, and the service life can be extended. The positioning concave offers an assured and firm engagement to improve the convenience in use. The assembly of the portable extension memory storage device can be finished without using any other threaded elements or locking elements, thus reducing the material and labor cost.

Abstract: A monocoque housing for a mobile unit comprises a base, an end cap, and an isolation gasket. The mobile unit includes an electronic stack assembly. The base has an opening. The end cap is adapted to removably couple with the base. The end cap includes a cap and a frame where the frame is received by the base through the opening so that the cap covers the opening. The isolation gasket is disposed between the frame and the electronic stack assembly. The electronic stack assembly is not mechanically fastened to the isolation gasket. When the mobile unit experiences a shock load, the isolation gasket absorbs the shock load to reduce the shock load on the electronic stack assembly.

Abstract: A portable electronic device includes a first body, a second body, a rotating member and a covering member. The second body is connected to the first body and comprises an opening. The rotating member is rotatably disposed in the second body between a first position and a second position. When the rotating member is in the first position, the rotating member is exposed outside of the second body through the opening, and when the rotating member is in the second position, the rotating member is hidden in the second body. The covering member is connected to the rotating member and disposed in the second body between a third position and a fourth position. When the rotating member is in the first position, the covering member is in the third position, and when the rotating member is in the second position, the covering member is in the fourth position.

Abstract: A support for a fragile and/or brittle front piece includes a base plate member and a rim. The support is shaped to receive a specifically shaped piece of brittle material, such as ceramic, sapphire, precious or semi precious stone. The piece of brittle material has a front surface, a rear surface and sides. The rear surface is secured to a base plate of the support and a rim of the support surrounds the edges of the piece of brittle material.

Abstract: An electronic device and a retreating apparatus are disclosed. The retreating apparatus comprises at least one moving element, at least one first elastic element, an operating element, and at least one linking element. When the electronic device connects to an external device via connecting interfaces, the retreating apparatus disposed in the electronic device is capable of detaching the external device successfully from the electronic device by different working types.

Abstract: The present invention relates to an electrical device, comprising: a support made out of an electrically-insulating material, said support being configured to be fastened under an item that can be handled by a user, or forming part of the item; at least one battery; at least one electrical component; and electrical conductors that connect the battery to the electrical component; the electrical conductors including at least one electrical conductor that is fastened mechanically to the support, said electrical conductor being capable of being, in particular configured to be, subjected to movement relative to the battery or to another conductor in response to thrust exerted vertically on the device, in such a manner that the electrical component is automatically powered electrically when the item is picked up off a surface on which it was standing, and in such a manner that the component automatically ceases to be powered electrically when the item is put back on said surface.

Abstract: A computer monitor is supported by a stand connected to the back of the monitor. A shelf is positioned behind the computer monitor, where the shelf is connected to either the stand or the computer monitor back surface. The shelf has a flat portion which is essentially horizontal for holding various items.

Abstract: An electronic device housing may contain a display module. The display module may contain layers of material such as a color filter layer and a thin-film transistor layer. These layers of material may be mounted in a display module chassis. A cover glass may cover the display module. The housing may have springs that mate with corresponding holes in the chassis of the display module to hold the display module in place within the housing. The springs may flex about a flex axis that is perpendicular to a planar rear housing surface and the planar layers of the display module. A disassembly tool may be inserted into a gap between the cover glass and housing sidewalls. When the disassembly tool is rotated, a fin on the tool may press against an engagement structure in the spring and may release the spring from the display module.

Abstract: The present invention provides for repeatedly pulsing coolant through a first channel exposed to heat-generating computer components. The pulsing involves a relatively low baseline coolant flow rate with repeated excursions to a relatively high expulsion coolant flow rate.

Abstract: A chassis includes a main box body. The said main box body includes a back panel, an upper cover panel, a lower cover panel, a left side panel and a right side panel connected with each other. An upper single panel slideway and a lower single panel slideway are provided in the main box body for fixing single panels. A fan is provided on the top of the main box body. A power distribution unit is provided on the bottom of the main box body. A connection portion is provided in the chassis for connecting the fan and the power distribution unit. The connection portion is a groove provided from the top to the bottom of the side panel for holding acable or two holes provided on the upper and the lower locations of the side panel for guiding the cable.