An article transport facility includes a plurality of mobile bodies movable along a single track for transporting articles, and a control device for controlling movement of the mobile bodies. The control device is capable of executing a joint moving operation for moving the mobile bodies in combination. In this operation, a first mobile body which is one of the mobile bodies pushes a second mobile body which is another of the mobile bodies.

This invention relates to an article transport facility, and more particularly to an article transport facility having a plurality of mobile bodies movable forward and backward along a single track for transporting articles, and a control means for controlling operation of the mobile bodies. The invention relates also to a method of operating the facility.
The above article transport facility transports articles by reciprocal movement of each of the mobile bodies along a track. This facility realizes improved transport capacity by transporting articles with the plurality of mobile bodies.
A conventional article transport facility as noted above has two mobile bodies for moving forward and backward along the track. The control means is provided for controlling operation of the two mobile bodies to move and transport articles as separated from each other at least by a predetermined distance (see Japanese Patent Publication (Unexamined) H11-59819, for example).
In the conventional article transport facility, when the distance between the two mobile bodies moved in transporting articles becomes less than the predetermined distance, the two mobile bodies are stopped to avoid a collision.
Thus, the above conventional article transport facility, when moving the plurality of mobile bodies for article transport, does not permit the distance between the two mobile bodies adjoining longitudinally of the track to become less than the predetermined distance. In this case, there is a possibility that the plurality of mobile bodies cannot move efficiently for article transport.
When, for example, the two mobile bodies are moved in order to transport articles to two locations close to each other longitudinally of the track, the two mobile bodies are moved close to each other. When the distance between the two mobile bodies becomes less than the predetermined distance, the mobile bodies are stopped. Therefore, the mobile bodies cannot be moved efficiently for article transport. When an abnormality occurs with one of the mobile bodies, the abnormal mobile body cannot be moved by using the normal mobile body.
When the two mobile bodies standing still close to each other longitudinally of the track are moved to transport articles, for example, the mobile body located forward is first moved. The rearward mobile body is moved only after the two mobile bodies become spaced apart by the predetermined distance, In this way, it is necessary to perform a operation for making the distance between the two mobile bodies at least the predetermined distance, Thus, the plurality of mobile bodies cannot be moved efficiently for article transport.
In order to eliminate the above inconvenience, for example, a coupling device may be provided for coupling the two mobile bodies. When moving the two mobile bodies for article transport, the two mobile bodies may be coupled by the coupling device to move together. In this case, however, the coupling device must be attached to and detached from the mobile bodies manually. This operation is time-consuming, and consequently the plurality of mobile bodies cannot be moved efficiently for article transport.
In order to move the two mobile bodies together for article transport, it is also conceivable to attach a coupling device with an actuator to the mobile bodies, so that the mobile bodies are coupled by operation of the actuator. In this case, the coupling device with the actuator must newly be provided for the mobile bodies, resulting in a complicated construction.

Article transport facility and a method of operating the facility


According to the present invention, a semiconductor package is provided. In one version of the invention, the semiconductor package includes a laminated substrate having a semiconductor die mounted on its upper surface, electrical connections between bond pads on the semiconductor die and conductive traces on the substrate, as well as electrical connections between the conductive traces and electrical contacts on the lower surface of the substrate. The semiconductor package also includes a molded covering on the upper surface of the substrate which covers the semiconductor die and the electrical connections. The molded covering has a mold body portion and a mold gate runner which extends from the mold body portion to an edge of the substrate. The mold gate runner is provided with a surface that is substantially even with the edge of the substrate and rises perpendicularly from the upper surface of the substrate.

As the ability to fabricate greater numbers of transistors on a given semiconductor die size increases, the circuits on the die become more complex and require a greater number of external electrical connections. To accommodate the required number of external contacts, semiconductor packages have evolved from lead frame based packages, such as dual-in-line ("DIPs") and quad-flat-pack ("QFP") packages, to laminated substrate based packages, such as ball grid arrays ("BGA").
FIG. 1 is a cross-sectional view of a conventional BGA package. As shown, the package comprises a laminated substrate 106 formed of, for example, a ceramic or plastic material such as epoxy-glass. Electrically conductive traces (not shown) are formed on conductive layers of the substrate 106. Methods for forming conductive traces are known in the art. For example, photo-lithographic techniques may be used to image a desired pattern into a photo-resist material disposed on a conductive layer of the substrate 106. The photoresist material is then "developed," i.e., the photoresist material not exposed by the image, is removed, thereby creating a corresponding pattern of exposed conductive material on the substrate. The exposed conductive material is then removed in an etching process. Finally, the remaining photoresist material is removed, leaving the desired pattern of conductive material on the substrate.
Electrical connections between the layers are formed by conductive vias, such as via 114. Vias are formed in the substrate by known techniques, such as mechanical or laser drilling. After the via is created, it is plated with a conductive material to provide the desired electrical contact. A plurality of electrical contacts to the conductive traces of the package are provided on the lower surface of the package substrate 106. Solder balls 108 are attached to each of the contacts to allow electrical connection between the semiconductor package and external electronic components, such as printed wire boards. Solder balls 108 are conventional and typically are constructed from a lead-tin alloy and are attached to the contacts by well known methods such as re-flow soldering. Of course, other conventional electrical connectors could be substituted for the solder balls 108, such as conductive pins attached to contacts on the lower surface of substrate 106.
A semiconductor die 102 is mounted to the upper surface of the package substrate 106 by a suitable die attach material 110, such as epoxy. Electrical connection between bond pads on the die 102 and the conductive traces on the substrate 106 is provided by bond wires 104. Of course, in addition to the bond wires shown, different methods of providing electrical connections from the die to the package are also well known in the art, such as wire bonding and C4, or "flip-chip" techniques.
All semiconductor packages must not only provide for a number of electrical connections to be made from bond pads on a semiconductor die to external contacts on the package, but must also provide physical protection to prevent damage to the die during handling. To protect the die 102 and bond wires 104, a molded covering 112 is formed on the substrate 106. Generally, molded covering 112 is formed on the package by a transfer or injection molding process. Conventional transfer molding processes are known to those of skill in the art and are described in, for example, U.S. Pat. No. 5,635,671, issued to Freyman et al., incorporated herein by reference. This is explained in greater detail with respect to FIG. 2.
FIG. 2 is a cross-sectional view of a conventional two-piece mold. In this case, the mold comprises an upper mold section 200 which is adapted to mate with a lower mold section 202. The lower mold 202 has a recess formed therein for receiving and holding the semiconductor package during the molding process. The semiconductor package is conventional and includes a package substrate 106 having a semiconductor die 102 mounted thereon by means of a die attach material 110. Electrical connection between the die 102 and the substrate 106 is provided by bond wires 104. Lower mold section 202 also has an opening formed therein for receiving a transfer ram 210. The transfer ram 210 is slideably inserted into an opening in lower mold section 202 to force molding material into the cavity 204 as will be discussed in greater detail herein.
A cavity 204 is formed in the upper mold section 200 such that when the mold sections are placed together the cavity 204 is disposed over the die 102 and bond wires 104. As seen from the figure, the shape of the cavity 204 controls the shape of the molded covering. It will also be noted that the sides of the cavity 204 are provided with a slight slope to make removal of the package from the mold easier. Upper mold section 200 is also provided with a cavity 206 which is designed to receive the molding material 208. Cavity 206 is sometimes referred to as the "pot." Molding material 208 is generally a plastic material which hardens upon curing. A channel 212 is formed in upper mold section 200 which connects the pot 206 to the cavity 204. The channel 212 is sometimes referred to as the "runner" channel.
It will be understood by those of skill in the art that the mold sections are generally designed to fit within a frame, referred to as a "chase", during the molding process. The mold sections are often formed as separate removable units, referred to as "bars". The bar which corresponds to the upper mold section will be referred to herein as the "cavity bar". A multiplicity of mold cavities, such as cavity 204, are machined into the cavity bar to allow molding of several packages at once. The mold bars are typically removable from the chase so that the same chase can be used to mold packages of different sizes by simply substituting different mold bars. Similarly, a multiplicity of pots are also often formed on a separate bar, referred to as a "runner bar", to allow substitution of different pots for different packaging applications.
To facilitate simultaneous molding of a number of packages, individual substrates are provided on a substrate strip which contains multiple substrates which are later separated or "singulated", after the molding process. This is described in greater detail with respect to FIGS. 3A-3B.
FIG. 3A is a top view of a substrate strip 300. Substrate strip 300 contains four substrates, 302 (for simplicity, only two substrates are denoted by the number 302). Substrate strip 300 is also provided with a number of tooling holes, such as tooling hole 304, around its outer perimeter to allow the substrate strip 300 to be attached to other devices in the molding process, such as the cavity bars. Slots 306 are formed on substrate strip 300 between each of the substrates 302. Slots 306 operate to provide stress relief to the strip 300 to reduce or prevent warping during the molding process. Punching holes 305 are also provided on strip 300 at the comer of the substrates 302. Punching holes 305 are useful during the singulation process to reduce or prevent rough edges from being created on the substrates when they are punched out of the strip. Each substrate 302 is provided with a die attach area 307 to allow attachment of a semiconductor die (not shown) to the substrate 302. The die is attached both mechanically, by for example, die attach material, and electrically, by for example, bond wires or flip-chip solder ball connections.
It will be understood that substrates 302 are substantially the same as substrate 106 shown in FIG. 1 in that they are formed from a laminate material and are provided with conductive traces and vias, as discussed previously. The opposite side of strip 300 (not shown) is provided with conductive regions intended to provide electrical connection between conductive traces on the substrate and corresponding electrical contacts on external circuitry, such as printed wire boards ("PWB"). Such electrical connections are often referred to as second level interconnects and are implemented by, for example, solder balls as shown in FIG. 1.
FIG. 3B is a top view of conventional molding equipment with substrate strips attached. As shown, the molding equipment includes a mold chase 308. The mold chase allows attachments of cavity bars 310 on each side which are separated by runner bar 312. Substrate strips 300 are attached to cavity bars 310 by tooling holes 304 which fit over corresponding pins projecting from the top surface of the cavity bars 310. Slots 306 are, again, provided between the substrates 302 to help prevent warping of the strip 300.
Each substrate 302 is aligned with a cavity 204 (indicated by dotted lines) formed on the cavity bar 310. The strips 300 are disposed on the cavity bars 310 such that the upper, or die attach surface, faces the top surface of the cavity bar 310. Thus, the die and bond wires mounted to each of the substrates will be enclosed by the cavity 204. For simplicity, only one cavity is denoted by the numeral 204. It is to be understood, however, that the other cavities illustrated in the figure are substantially similar, and the following description is equally applicable to them.
Cavity 204 is connected by runner channel 212 to pot 206. Pot 206 is one of four substantially similar pots formed on runner bar 312. Each pot feeds two cavities on either side of the runner bar 312. However, this is for purposes of illustration, and numerous other arrangements are known in the art. Runner channel 212 joins cavity 204 at gate 316.
Since the molding operation is substantially the same for each of the substrate strips 300, it will be described with respect to a single package substrate 204 and its associated molding material pot 206, for the sake of simplicity. After the substrate strips 300 are attached to the cavity bars, the molding material is placed into the pot 206, and the bar containing the lower mold sections are pressed against the cavity and runner bars shown in the figure. This holds the substrate strips 300 firmly in place. Transfer rams (not shown) are then pushed into the pot 206 in order to force the mold material through runner channel 212 and gate 316 and into cavity 204. A sufficient amount of material is forced into cavity 204 to completely fill the cavity and enclose the die and bond wires (not shown) on the package substrate 302. After the mold material cures, the bars are separated and the substrate strips 300 removed. The package substrate 302 is then singulated by punching it out of the strip 300, resulting in a molded semiconductor die, such as that shown in the cross-section view of FIG. 1.
However, one shortcoming of the above process is apparent. Specifically, the mold material not only fills the cavity 204 but also the gate 316, runner channel 212 and pot 206. Therefore, when the mold material is cured, the cured material not only covers the die and bond wires, but also extends along the surface of the package substrate and outward from the package along the runner channel 212 to the pot 206. This excess cured material is often referred to as the "runner" and must be removed from the substrate strips before they are singulated.
Accordingly, gate 316 is generally made somewhat smaller in cross-sectional area than the runner in order to assist in the "degating" process, i.e., the removal of the excess material. Generally, the degating process is performed simply by peeling the runner away from the substrate until it separates at the gate. However, the mold material tends to adhere to the surface of the package substrate during the degating process. This adhesion is likely to cause damage to the surface of the package substrate as the mold material is peeled away due to tearing or rupturing of the substrate. The damage may be merely cosmetic, or if severe enough, may fracture the substrate or damage electrically conductive traces on the substrate surface, resulting in functional damage to the substrate. Additionally, peeling away the runner may also tear away part of the solder mask on the substrate surface, exposing the metal traces underneath to oxidation, or attack by other chemical pollutants. Even if no damage is done to the package substrate, the degating process may still weaken the seal between the molded body and the upper surface of the substrate, thus increasing the chances of moisture penetration in the package.
Efforts at addressing this problem involve providing a metallic trace, such as gold, on the upper surface of the package substrate which contacts the gate and runner. Since conventional molding materials do not adhere well to gold, it is easier, and less likely to cause damage, to peel away the runner. However, adding such an additional trace increases the overall cost of the package. Moreover, the trace also requires the use of a substantial amount of area on the package substrate, thus reducing the total amount of available area for routing conductive traces to be used for electrical connections on the package. Therefore, there is a need for a semiconductor package which allows easy removal of the runner without risk of damage to the package substrate. It is also desirable that such a package will not require additional manufacturing step, or a reduction in the amount of available area for routing conductive traces.

Molded laminate package with integral mold gate


A system and method for reprogramming a non-volatile memory of one or more on-board vehicle computers through a serial communication link between an off-board controller and the on-board vehicle computer. An interface circuit is also provided on the vehicle in order to process the command signals from the portable controller which will enable the non-volatile memory to receive and store new computer program code. The method follows a predetermined transfer protocol which assists in preventing the existing computer program code stored in the non-volatile memory from being improperly erased or re-written. This transfer protocol includes the transmission of a command signal from the off-board controller which has a voltage level that exceeds the voltage level of any signal which may recognized on the serial communication link.

The present invention generally relates to on-board vehicle computer systems, and particularly to a system and method for reprogramming on-board vehicle computer systems.
For over a decade, computers have been used on vehicles, such as automobiles and trucks, to control particular operations of one or more mechanical vehicle systems. In this regard, one of the first and still principal applications of vehicle computer technology has been to control various aspects of the engine used to drive the vehicle. In recent years, computers have also come to be used in a wide variety of vehicle systems, such as transmission systems, brake systems, suspension systems, operator control panels and even motorized seats. An example of one such computerized vehicle system is described in Leising et. al U.S. Pat. No. 4,875,391, issued on Oct. 24, 1989, entitled "Electronically-Controlled, Adaptive Automatic Transmission System". This commonly assigned patent is hereby incorporated by reference. As described in this patent, the vehicle transmission system includes a computer circuit which controls a plurality of solenoid-actuated valves that regulate the flow of hydraulic fluid within the transmission.
Due to the complexity and inter-relationship between some of these vehicle systems, on-board computer communication systems have also developed to enable data and other signals to be passed between particular vehicle computers. These communication systems typically include a plurality of wires which are connected to the vehicle computers in a particular electronic configuration, generally referred to as a "bus".
One example of an appropriate vehicle bus structure is represented by the Chrysler Collision Detection ("C.sup.2 D") Serial Data Bus. This technology is described in the following publications and patents: SAE paper No. 860389, entitled "Chrysler Collision Detection (C.sup.2 D)--A Revolutionary Vehicle Network", by Frederick O. R. Miesterfeld, 1986; SAE paper No. 890529, entitled "The All-Adaptive Controls for the Chrysler Ultradrive Transaxle", 1989; U.S. Pat. No. 4,706,082, entitled "Serial Data Bus For Intermodule Data Communications," which issued on Nov. 10, 1987; and U.S. Pat. No. 4,719,458, entitled "Method of Data Arbitration and Collision Detection In A Data Bus," which issued on Jan. 12, 1988; and U.S. Pat. No. 4,739,323, entitled "Serial Data Bus For Serial Communication Interface (SCI), Serial Peripheral Interface (SPI) and Buffered SPI Modes of Operation," which issued on Apr. 19, 1988; and U.S. Pat. No. 4,739,324, entitled "Method for Serial Peripheral Interface (SPI) in a Serial Data Bus," which issued on Apr. 19, 1988; and U.S. Pat. No. 4,742,349 entitled "Method for Buffered Serial Peripheral Interface (SPI) in a Serial Data Bus", which will issue on May 3, 1988. These co-assigned patents and the identified publications are all hereby incorporated by reference.
In this regard, it should be noted that the engine controller and the transmission controller discussed in the above referenced U.S. Pat. No. 4,875,391 are both connected to the C.sup.2 D Serial Data Bus. This Serial Data Bus may also be accessible to off-board vehicle computers through one or more diagnostic connectors on the vehicle. In this regard, it should be appreciated that any vehicle bus structure needs to be accessible to off-board computer systems in order to permit the bus itself to be tested and permit direct access to and communication with any of the vehicle computers tied to the vehicle bus.
One or more of these vehicle diagnostic connectors also typically provide separate communication links or channels with both the vehicle's engine control computer and the vehicle's transmission control computer. These communication links are generally designed to conduct serial communications directly with these particular on-board vehicle computers during certain diagnostic procedures.
In any event, diagnostic connectors have been employed since engine computers were first used on vehicles to permit communication between on-board and off-board computers. Thus, for example, data being gathered by the on-board vehicle computer from various sensors (such as engine speed and manifold pressure) may be transmitted to an off-board computer for programmed or operator analysis. Additionally, it may be desirable for an off-board computer to transmit commands which will actuate or energize electronically controlled devices on the vehicle (such as the air switch solenoid) to examine the response achieved. As another example of possible forms of communication, it may be advantageous for a test program from an off-board computer to be "down-loaded" into the transmission control computer in order to execute one or more prescribed tests of the transmission system before the vehicle leaves the manufacturing facility.
As with any computer system, an on-board vehicle computer cannot function without a set of instructions for the computer hardware to follow. This set of instructions may comprise one or more computer programs which are sometimes referred to generically as computer software. In order for the computer hardware to use this set of instructions, the computer programs need to be stored in some medium which is readily accessible to the computer's hardware. In terms of on-board vehicle computers, the computer programs are typically stored in a form of circuitry which will retain the computer program even when there is no electrical power connected to the computer circuit.
Specifically, on-board vehicle computer programs are stored in one or more types of non-volatile ROM, which stands for "Read-Only Memory". ROM circuits come in various types, such as permanent circuits (ROM), programmable circuits (PROM), erasable-programmable circuits (EPROM) or electrically erasable-programmable circuits (EEPROM). Each of these ROM circuits are produced in the form of a semiconductor integrated circuit (IC) or circuit "chip" which may be separately mounted to a circuit board or contained in a larger chip that includes other circuits as well.
With a permanent ROM, the computer programs are hard-wired into the chip during the manufacture of the chip, and the program cannot be changed. With a PROM, the computer program is electronically inserted or injected into the chip after it has been manufactured. The EPROM is like a PROM except it has the added capability of erasing the entire computer program stored in the chip by irradiating the chip with ultra-violet light for a period of time on the order of 20 minutes. Once the program is erased, then another computer program may be inserted into the chip to take its place. The EEPROM is similar to the EPROM in that it permits erasure and subsequent re-programming. However, with an EEPROM, the entire computer program need not be erased, and the erasure may be accomplished very rapidly (e.g., 1-2 seconds) through the application of electrical signals.
Additionally, a new form of non-volatile ROM chip, known as a "flash memory", has also become available. A flash memory chip is like an EEPROM in terms of being electrically erasable and re-programmable. However, unlike an EEPROM, individual memory cells cannot be erased in a flash memory chip. At the present time, a flash memory only has the capability of erasing selected sections of the memory or the entire contents of the memory. Nevertheless, a flash memory has several advantages over EEPROMs, including high density and the ability to operate at a low voltage (e.g., 5 volts). A further description of flash memories may be found in an IEEE Spectrum article by Pashley et. al., entitled "Flash memories: the best of two worlds", December, 1989. This article is hereby incorporated by reference.
As will be appreciated from the above discussion of ROM memories, each of these memory types present different options when it is desired to update, revise or expand upon the computer programs which are stored in the memory chip. With permanent ROMs and PROMs, the chip itself has to be removed from the circuit board and replaced with a new memory chip which contains the desired computer programs. With an EPROM, the memory chip still needs to be removed from the circuit board in order to be erased. However, the EPROM chip may then be replaced on the circuit board after the new program has been injected into the chip.
Due to the amount of time, labor and possible replacement costs involved in these procedures, none of these three types of ROM chips present particularly attractive options for applications where it may be desirable to periodically update the software stored on the memory chip. In contrast, EEPROMs and flash memories do offer a potentially viable option for updating or otherwise replacing existing software. In this regard, it is generally not necessary for a EEPROM or flash memory chip to be removed from a circuit board in order to erase all or part of a computer program and subsequently re-program the appropriate memory cells. Additionally, as discussed above, the entire erasure/reprogramming procedure for these memory chips may be carried out very quickly.
With respect to the computer programs used in on-board vehicle computer systems, a need exists to provide a way which will permit these computer programs to be easily updated or changed at a qualified dealership. As each model year brings further sophistication to on-board vehicle computer systems and their computer programs, it would be a distinct benefit to the consumer to permit one or more of the vehicle computers to be upgraded with the latest software on an economical basis.
Accordingly, it is a principal objective of the present invention to provide a secure system and method for reprogramming on-board vehicle computers.
It is a more specific objective of the present invention to provide a secure system and method for reprogramming on-board vehicle computers which is reliable, quick and economical.
It is another objective of the present invention to provide a secure system and method for reprogramming on-board vehicle computers which minimizes the amount of hardware changes required to reprogram all or part of computer programs residing in an on-board memory chip.
It is a further objective of the present invention to provide a secure system and method for reprogramming on-board vehicle computers which utilizes the existing vehicle communication structure for transmitting new computer instructions to the on-board memory chip being reprogrammed.

System and method for reprogramming vehicle computers


To perform a high dustproof when a disk drive apparatus records and/or reproduces information signals on a disk shape recording medium, which is stored rotatably within a disk cartridge. The present invention provides a disk drive apparatus for recording and/or reproducing information signals on a disk shape recording medium, which is stored rotatably within a disk cartridge comprising a case having a cartridge storing space in which the disk cartridge is inserted, rotatably driving means for holding the disk shape recording medium, which is stored within the disk cartridge, which is inserted in the cartridge storing space and for rotatably driving the disk shape recording medium, shielding means for defining a shielded space by covering a surrounding area of the rotatably driving means for holding the disk shape recording medium and a filter for removing a dust or the like inside of the cartridge storing space. The shielded space and the cartridge storing space communicate each other via said filter.

1. Field of the Invention
The present invention relates to a disk drive apparatus for recording and/or reproducing a recording medium with a disk shape such as a magnetic disk or an optical disk, which is stored rotatably inside a disk cartridge.
2. Prior Art
The conventional art, for example, may be exemplified by a Removable Hard Disk Drive (hereinafter referred to as an R-HDD) as a mass storage device, which is used in an information processing apparatus such as a computer. The R-HDD records or reproduces information signals on a magnetic disk, which is rotatably stored inside a disk cartridge. The disk cartridge may be used detachably for the R-HDD.
FIG. 1 shows an embodiment of a configuration of an R-HDD. FIG. 2 shows an embodiment of a configuration of a disk cartridge to be stored in the R-HDD.
As shown in FIG. 1, the R-HDD 100 comprises a spindle motor 102, a chucking magnet 103, a head actuator 105 and a holder 106 inside an apparatus body 101 of an R-HDD 100, in which a disk cartridge is inserted. The spindle motor 102 rotatably drives the magnetic disk, which is rotatably stored inside the disk cartridge. The chucking magnet 103 comprises a permanent magnet attached to the spindle motor 102. The head actuator 105 is provided with a floating head slider 104, on which a magnet head for recording or reproducing the information signals on the magnetic disk is mounted, at a head end. The holder 106 holds the disk cartridge that is inserted inside the apparatus body 101.
On the other hand, as shown in FIG. 2, in a disk cartridge 200, a magnetic disk 201 is clipped by a cartridge body 204, comprising an upper half 202 and a lower half 203. In this arrangement, an approximately center of the magnetic disk 201 is provided with a hub 205. The hub 205 comprises a ferromagnetic body designed to chuck using a permanent magnet. On the contrary, in the cartridge body 204, an opening (hereinafter referred to as an opening for a hub) 206 is defined on an approximately center of the lower half 203. The opening 206 causes the hub 205 attached to the magnetic disk 201 to face outside. The cartridge body 204 is provided with an opening (hereinafter referred to as an opening for a head) 207 at a portion of the build-up-peripheral-wall 204a of the side face. The opening 207 causes the head actuator 105 of the R-HDD 100 to approach inside of the disk cartridge 200. Further, in order to prevent the dust or the like from inserting therein, the disk cartridge 200 is provided with a shutter mechanism 208 for shutting up the opening for the hub 206 and the opening for the head 207 when they are not used.
In the R-HDD 100, when the disk cartridge 200 is inserted inside of the apparatus body 101, the opening for the hub 206 and the opening for the head 207 of the disk cartridge 200 are open. Then, the disk cartridge 200 comes down toward the spindle motor 102 together with the holder 106. At this time, the hub 205 of the magnetic disk 201 facing to outside from the opening for the hub 206 of the disk cartridge 200 is stuck to the chucking magnet 103 attached to the spindle motor 102. As a result of that, the spindle motor 102 can hold the magnetic disk 201, which is stored in the disk cartridge 200.
In the R-HDD 100, upon reproducing the record, the spindle motor 102 rotatably drives the magnetic disk 201, which is stored inside the disk cartridge 200. Also in the R-HDD 100, if the magnetic disk 201 is rotatably driven at a predetermined number of rotations, the head actuator 105 approaches from the opening for the head 207 of the disk cartridge 200. Then, the floating head slider 104 attached to the head end of the head actuator 105 records or reproduces the information signals on the magnetic disk 201 by the magnet head mounted on the floating head slider 104. At the same time, the floating head slider 104 is floating slightly by the air film which is generated between the floating head slider 104 and the magnetic disk 201 which is rotating.
In the R-HDD 100, the disk cartridge 200 is discharged from the apparatus body 101 of the R-HDD 100 by an adverse operation to the above stated operation when the usage of the disk cartridge 200 was over.
As described above, upon recording or reproducing the information signals on the magnetic disk 201 which is stored inside of the disk cartridge 200, R-HDD 100 is provided with the floating slider 104, floating over a surface for recording signals of the magnetic disk 201, which is rotating with a minute distance according to an aerodynamic influence. As a result of that, the magnet head, which is mounted, on the floating slider 104 and the magnetic disk 201 can be prevented from being touched to be worn out.
However, in the R-HDD 100, the magnetic disk 201 is rotating at a high speed as the floating head slider 104 is floating over a main surface of the magnetic disk 201 which is rotating with a minute distance, for example, some tens of nano meters. On this account, the R-HDD 100 is very weak for the dust or the like. Accordingly, if the dust or the like inserts inside of the disk cartridge 200 and it sticks to the surface of the magnetic disk 201, even the very minute dust may cause the disk cartridge 200 to record the information signals defectively. Further, in some instances, it is feared that the dust or the like inserts between the magnetic disk 201 and the floating head slider 104 so that the magnetic disk 201 is damaged and the magnet head mounted on the floating head slider 104 is physically clashed (head clash).
The magnetic disk 201 rotates inside of the disk cartridge 200 so that airflow is generated on the main surface of the magnetic disk 201 in the R-HDD 100. Then, a kind of influence caused by a centrifugal pump is generated, so that a vicinity of a rotation center of the magnetic disk 201 inside of the disk cartridge 200 comes to have a negative pressure. As a result of that, outside air containing the dust or the like communicates through the opening for the hub 206, which is provided on the center portion of the lower half 203 of the cartridge body 204, to flow into inside of the disk cartridge 200. At the same time, air inside of the disk cartridge 200 flows out from the opening for the head 207, which is disposed on the build-up-peripheral-wall 204a of the side face of the disk cartridge body 204.
Therefore, there was the case that the outside air containing the dust or the like flowed into the opening for the hub 207 in the R-HDD 100, so that the inside of the disk cartridge 200 was polluted.
Also, there was the case that the outside air containing the dust or the like flowed into the inside of the apparatus body 101 of the R-HDD 100, inserted the disk cartridge 200, even from a small gap of the apparatus body 101 due to spreading or locally decreasing of a pressure. As a result of that, the inside of the apparatus body 101 and the inside of the disk cartridge 200 was polluted.
There is an idea that a surrounding area of the opening for the hub 206 of the disk cartridge 200 is shielded by a shielding member to prevent the outside air containing the dust or the like from flowing into the inside of the R-HDD 100. However, since the vicinity of the rotation center of the magnetic disk 201 inside of the disk cartridge 200 comes to have a negative pressure in the R-HDD 100, a pressure of the vicinity of the spindle motor 102 for holding the magnetic disk 201 also comes down. Thus, there is a problem that a grease inside of the spindle motor 102, an operational fluid or air bubbles inside of the magnet fluid seal blows out to pollute the inside of the disk cartridge 200.
The present invention has been made taking the foregoing problem into consideration, an object of which is to provide a disk drive apparatus for performing a high dustproof when recording and/or reproducing information signals on a disk shape recording medium, which is stored rotatably inside of a disk cartridge.
A disk drive apparatus for recording and/or reproducing information signals on a disk shape recording medium, which is stored rotatably within a disk cartridge comprises a case having a cartridge storing space in which the disk cartridge is inserted, rotatably driving means for holding the disk shape recording medium, which is stored within the disk cartridge, which is inserted in the cartridge storing space and for rotatably driving the disk shape recording medium, shielding means for defining a shielded space by covering a surrounding area of the rotatably driving means for holding the disk shape recording medium and a filter for removing a dust or the like inside of the cartridge storing space. The shielded space and said cartridge storing space communicate each other via said filter.
In the above arrangement of the disk drive apparatus, the disk shape recording medium, which is stored inside of the disk cartridge is rotatably driven by rotating driving means, so that the pressure in the surrounding area of the rotating driving means for holding the disk shape recording medium becomes negative.
A shielded space covering the surrounding area of the rotating driving means is defined by the shielding means in this disk drive apparatus. The rotating driving means holds the disk shape recording medium. Therefore, air containing the dust or the like does not flow into the inside of the disk cartridge from a surrounding area of the rotating driving means for holding the recording medium in the disk, so that the inside of the disk cartridge may be kept clean. In this disk drive apparatus, the shielded space communicates to the cartridge storing space via a filter. Accordingly, air, which is cleaned by a filter, can be supplied from the cartridge storing space to the shielded space, that is, into the inside of the disk cartridge. As a result, the dust or the like does not pollute the inside of the disk cartridge so that a pressure in the shielded area can be prevented from extremely lowering.
The air in the cartridge storing space of the disk drive apparatus is inlet to the shielded space side through the filter. Accordingly, the air in the cartridge storing space can be cleaned.
The pressure in the cartridge storing space of the disk drive apparatus is higher than the pressure in the outside, so that the outside air containing the dust or the like can be prevented from flowing into the cartridge storing space.
The shielding means covers the outer circumference of the rotatably driving means and preferably comprises a member of connecting under pressure configured so as to connect to the disk cartridge under pressure. Thus, the shielded space can be shielded with high accuracy to prevent the dust from inserting into the inside of the disk cartridge. The member for connecting under pressure is preferably made of an elastic material.
The filter is preferably arranged so as to be positioned in a vicinity of the side face in said cartridge storing space, in which said disk cartridge is inserted.
In the above case, it is possible to collect the dust, which is inserted from the outside of the cartridge storing space, effectively so as to clean the inside of the cartridge storing space.
The disk cartridge is provided with an opening in which a head for recording and/or reproducing said disk shape recording medium is inserted. The filter is preferably arranged so as to be positioned in a vicinity of the opening, which is defined in the disk cartridge of the cartridge storing space when the disk cartridge is stored in the cartridge storing space.
In the above case, it is possible to utilize a filter with a less pressure loss. Accordingly, a pressure in the shielded area can be prevented from extremely lowering.
The filter is preferably arranged to be positioned so as not to overlap with the disk cartridge in the cartridge storing space when the disk cartridge is stored in the cartridge storing space.
In the above case, it is possible to utilize the inside of the cartridge storing space effectively to thicken a wall of the filter.
The disk drive apparatus preferably comprises a supporting plate for supporting the driving means. The shielded space and the cartridge storing space preferably communicate with each other via a duct line having a linear groove which passes through a rotation center of the disk shape recording medium, which is defined on the supporting plate.
In this state, it is possible to suppress the rigidity of a supporting plate for supporting the driving means so that vibrations occurred in the supporting plate can be prevented.
As described above in detail, the disk drive apparatus according to the present invention is provided with the shielded space for covering the surrounding area of the rotating driving means, which is defined by the shielding means in the disk drive apparatus. The rotating driving means holds the disk shape recording medium. Therefore, the air containing the dust or the like does not flow into the inside of the disk cartridge from the surrounding area of the rotating driving means for holding the recording medium in the disk, so that the inside of the disk cartridge may be kept clean. In this disk drive apparatus, the shielded space and the cartridge storing space communicate with each other via a filter. Accordingly, the air, which is cleaned by a filter, can be supplied from the cartridge storing space to the shielded space, that is, into the inside of the disk cartridge. As a result, the dust or the like does not pollute the inside of the disk cartridge so that a rapid decrease in pressure in the shielded area can be prevented.
The air in the cartridge storing space of the disk drive apparatus is inlet to the shielded space side through the filter. Accordingly, the air in the cartridge storing space can be cleaned.
The pressure in the cartridge storing space of the disk drive apparatus is higher than the pressure in the outside, so that the outside air containing the dust or the like can be prevented from flowing into the cartridge storing space.
Therefore, according to the disk drive apparatus of the present invention, a high dustproof can be obtained when recording and/or reproducing the information signals on the disk shape recording medium, which is stored rotatably inside of the disk cartridge.

Member for removing foreign particles within a cartridge storing space of a disk cartridge to be inserted into/removed from a disk drive apparatus


A solder preform having multiple layers including a solder layer filled with additives interposed between two unfilled layers for improved wettability. A solder preform having a sphere which contains a solder material filled with additives, and an unfilled surface layer for improved wettability. A thermal interface material having a bonding component and an additive component which is a CTE modifying component and/or a thermal conductivity enhancement component. Active solders containing intrinsic oxygen getters.

Thermal interface materials (TIMs) are critical to protect active semiconductor devices, such as microprocessors, from exceeding the operational temperature limit. They enable thermal bonding of the heat generating device (e.g., a silicon semiconductor) to a heat sink or a heat spreader (e.g. copper and/or aluminum components) without presenting an excessive thermal barrier. Different TIMs may also be used in the assembly of other components of the heat sink or the heat spreader stack that comprise the overall thermal impedance path.
Formation of a small thermal barrier is an important property of a TIM. The thermal barrier can be described in terms of effective thermal conductivity through the TIM and is preferably as high as possible. The effective thermal conductivity of the TIM is primarily due to the interfacial heat transfer coefficient as well as the (intrinsic) bulk thermal conductivity of the TIM. A variety of other properties are also important for a TIM depending on the particular application, for example: an ability to accommodate or avoid thermal expansion stresses when joining two materials, an ability to form a mechanically sound joint that is stable during thermal cycling, a lack of sensitivity to moisture and temperature changes, manufacturing feasibility, and cost.
Several classes of materials are being currently used as TIMs, for example, thermal greases, thermal gels, adhesives, elastomers, thermal pads, and phase change materials. Although the foregoing TIMs are adequate for many current semiconductor devices, the increased performance of semiconductor devices in the near future will render the presently known TIMs inadequate. Specifically, the thermal conductivity of current non-metallic TIMs generally does not exceed about 5 W/mK and is typically less than about 1 W/mK. However, TIMs that form thermal interfaces with effective thermal conductivities of about 50 W/mK or greater will soon be needed.
One alternative to the foregoing non-metallic TIMs is a solid metal sheet or preform made of a typical solder alloy. The metal TIMs ensure high thermal conductivity value (e.g., about 80 W/mK for an indium sheet). Metal TIMs may also exhibit a favorable solder or wetting behavior upon reflow which facilitates a low thermal interfacial resistance. During reflow, the solder and substrate are heated, the solder melts and wets by surface tension and/or local surface alloying. The interfaces consist of intermetallics or interdiffused metals with thermal properties that are frequently less desirable than those of the bulk TIM metal but much better than existing (polymer based) TIMs. In most cases, metallic TIMs have to be subjected to reflow in order to form reliable thermal interfaces. Metallic TIMs, however, can fail in certain applications due to the relatively large difference(s) between the coefficients of thermal expansion (CTEs) of the TIM and the semiconductor and/or heat sink components and the lack of compliance.

Thermal interface material and solder preforms


A multi-domain LCD device and a method for manufacturing the same are provided, in which it is possible to prevent an opening from being asymmetrical due to the bonding of margins of two substrates, thereby stabilizing peak transmittance characteristics and obtaining a wide viewing angle. The multi-domain LCD device includes first and second substrate being opposite to each other, a color filter layer having an opening on the first substrate, an insulating layer on the entire surface of the first substrate including the color filter layer, a first alignment layer on the insulating layer, a protrusion on the second substrate and corresponding to the opening of the first substrate, a second alignment layer on the entire surface of the second substrate including the protrusion, and a liquid crystal layer between the first and second substrates.

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 10-2002-0082534 filed in Republic of Korea on Dec. 23, 2002, the entire contents of which are herein incorporated by reference.
1. Field of the Invention
The present invention relates to a multi-domain liquid crystal display (LCD) device and a method for manufacturing the same, and more particularly to a multi-domain LCD device and a method for manufacturing the same suitable for improving a peak transmittance.
2. Discussion of Related Art
With development of information society, demands for various display devices increase. Accordingly, much effort has been made to research and develop various flat display devices such as liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD). Some species of the flat display devices are already applied to displays of various equipments.
Among the various flat display devices, the liquid crystal display (LCD) device has been most widely used due to the advantageous characteristics of thinness, lightness in weight, and low power consumption, whereby the LCD device substitutes for a cathode ray tube (CRT). In addition to the mobile type LCD devices such as a display for a notebook computer, the LCD devices have been developed for computer monitors and televisions to receive and display broadcasting signals.
Despite various technical developments in the LCD technology with applications in different fields, research in enhancing the picture quality of the LCD device has been in some respects lacking as compared to other features and advantages of the LCD device. In order to use the LCD device in various fields as a general display, the key to developing the LCD device lies on whether the LCD device can implement a high quality picture, such as high resolution and high luminance with a large-sized screen while still maintaining lightness in weight, thinness, and low power consumption.
Generally, an LCD device includes an LCD panel for displaying a picture image, and a driving part for applying a driving signal to the LCD panel. The LCD panel includes first and second glass substrates bonded to each other at a predetermined interval, and a liquid crystal layer injected between the first and second glass substrates.
The first glass substrate (TFT array substrate) includes a plurality of gate and data lines, a plurality of pixel electrodes, and a plurality of thin film transistors. At this time, the plurality of gate lines are formed on the first glass substrate at fixed intervals in one direction, and the plurality of data lines are formed at fixed intervals in perpendicular to the plurality of gate lines. Then, the plurality of pixel electrodes of a matrix arrangement are respectively formed in pixel regions defined by the plurality of gate and data lines crossing each other. The plurality of thin film transistors are switched according to signals of the gate lines for transmitting signals of the data lines to the respective pixel electrodes.
The second glass substrate (color filter substrate) includes a black matrix layer excluding light from regions except the pixel regions of the first substrate, R/G/B color filter layer displaying various colors, and a common electrode displaying the picture image. In case of an In-Plane Switching (IPS) mode LCD device, the common electrode is formed on the first glass substrate.
Next, a predetermined space is maintained between the first and second glass substrates by spacers, and the first and second substrates are bonded to each other by a sealant pattern having a liquid crystal injection inlet. At this time, the liquid crystal layer is formed according to a liquid crystal injection method, in which the liquid crystal injection inlet is dipped into a container having liquid crystal while maintaining a vacuum state in the predetermined space between the first and second glass substrates. That is, the liquid crystal is injected between the first and second substrates by an osmotic action. Then, the liquid crystal injection inlet is sealed with the sealant.
The LCD device is driven according to optical anisotropy and polarizability of liquid crystal. At this time, liquid crystal molecules are aligned with directional characteristics since the liquid crystal molecules respectively have long and thin shapes. In this respect, an electric field is applied to the liquid crystal for controlling the alignment direction of the liquid crystal molecules. That is, if the alignment direction of the liquid crystal molecules is controlled by the electric field, the light is polarized and changed by the optical anisotropy of the liquid crystal, thereby displaying the picture image.
The liquid crystal is classified into positive (+) type liquid crystal having positive dielectric anisotropy and negative (−) type liquid crystal having negative dielectric anisotropy according to electrical characteristics of the liquid crystal. In the positive (+) type liquid crystal, a longitudinal axis of a positive (+) liquid crystal molecule is in parallel to the electric field applied to the liquid crystal. Meanwhile, in the negative (−) type liquid crystal, a longitudinal axis of a negative (−) liquid crystal molecule is in perpendicular to the electric field applied to the liquid crystal.
FIG. 1 is an exploded perspective view illustrating some parts of a related art LCD device. As shown in FIG. 1, the related art LCD device includes lower and upper substrates 1 and 2 bonded to each other at a predetermined interval, and a liquid crystal layer 3 injected between the lower and upper substrates 1 and 2.
More specifically, the lower substrate 1 includes a plurality of gate lines 4, a plurality of data lines 5, a plurality of pixel electrodes 6, and a plurality of thin film transistors T. At this time, the plurality of gate lines 4 are formed on the lower substrate 1 in one direction at fixed intervals, and then the plurality of data lines 5 are formed in perpendicular to the plurality of gate lines 4 at fixed intervals, thereby defining a plurality of pixel regions P. Subsequently, the plurality of pixel electrodes 6 are respectively formed in the pixel regions P defined by the plurality of gate and data lines 4 and 5 crossing each other, and the plurality of thin film transistors T are respectively formed at crossing points of the plurality of gate and data lines 4 and 5. Also, the upper substrate 2 includes a black matrix layer 7 excluding light from regions except the pixel regions P, R/G/B color filter layer 8 for displaying various colors, and a common electrode 9 for displaying a picture image.
Herein, each thin film transistor T includes a gate electrode extending from the corresponding gate line 4, a gate insulating layer (not shown) on an entire surface of the lower substrate 1, an active layer on the gate insulating layer above the gate electrode, a source electrode protruding from the corresponding data line 5, and a drain electrode positioned opposite to the source electrode. Each pixel electrode 6 is formed of a transparent conductive metal having great light transmittance such as Indium-Tin-Oxide (ITO).
In the aforementioned LCD device, the liquid crystal layer 3 is aligned on the pixel electrode 6 by a signal applied from the thin film transistor T, and the light transmittance transmitting the liquid crystal layer 3 is controlled according to the alignment level of the liquid crystal layer 3, thereby displaying the picture image. The aforementioned LCD device drives the liquid crystal according to the electric field formed in perpendicular to the lower and upper substrates, in which transmissivity and aperture characteristics are great. Also, it is possible to prevent liquid crystal cells from being damaged due to static electricity in that the common electrode 9 of the upper substrate 2 serves as a ground.
Hereinafter, a related art multi-domain LCD device will be described with reference to the accompanying drawings.
FIG. 2 is a cross-sectional view illustrating a unit pixel of a related art multi-domain LCD device. As shown in FIG. 2, the related art multi-domain LCD device includes lower and upper substrates 21 and 22 being opposite to each other at a predetermined interval, and a liquid crystal layer 23 formed between the lower and upper substrates 21 and 22.
The lower substrate 21 includes a plurality of gate and data lines, a thin film transistor TFT, a passivation layer, a pixel electrode 24, and a first alignment layer 25. The plurality of gate and data lines crossing each other are formed on the lower substrate 21 to define a plurality of pixel regions. Also, the thin film transistor TFT having a gate electrode, a gate insulating layer, a semiconductor layer, an ohmic contact layer and source/drain electrodes is formed in the pixel region. Then, the passivation layer is formed on the entire surface of the lower substrate 21, and the pixel electrode 24 is formed on the passivation layer for being connected to the drain electrode. The first alignment layer 25 is formed on the entire surface of the lower substrate 21 including the pixel electrode 24.
The upper substrate 22 includes a black matrix layer 26 preventing light from leaking in the lower substrate 21 corresponding to the gate line, the data line and the thin film transistor, a color filter layer 27 formed on the entire surface of the upper substrate 22 including the black matrix layer 26, a common electrode 28 on the color filter layer 27, and a second alignment layer 29 on the common electrode 28.
Meanwhile, in the related art multi-domain LCD device, an opening 30 is formed in the color filter layer 27, thereby obtaining multi-domains. At this time, the opening 30 is formed when forming the color filter layer 27, and a VA mode is applied thereto, thereby forming a wide viewing angle.
However, the related art multi-domain LCD device has the following disadvantages. That is, the opening 30 is formed in the color filter layer of the upper substrate, whereby the opening may be asymmetrical by bonding margins of the lower and upper substrates. As a result, peak transmittance is unstable.

Multi-domain liquid crystal display device and method for manufacturing the same


A surgical implant for securing ligament grafts into a joint. The implant has back-biting threads that allow the implant to be advanced into bone by impaction. If necessary, the implant can be removed from the bone by rotation. The implant is used, for example, for knee ligament repair by forming a longitudinal socket in a bone. The socket is intersected by a transverse pin. A flexible strand is drawn with the pin through the bone. A looped portion of the flexible strand is diverted so as to protrude out of the entrance to the longitudinal socket. The ends of the flexible strand remain accessible on either side of the bone. The ligament graft is captured within the strand loop protruding from the entrance to the socket. The strand is retracted into the socket, drawing the graft into the socket by pulling on the accessible ends of the flexible strand. The graft is fixed in the socket using the transverse implant.

1. Field of the Invention:
The present invention relates to bone implants. More specifically, the invention relates to surgical implants for graft fixation in arthroscopic ligament repair in the knee using semitendinosus and gracilis tendon autografts.
2. Description of the Related Art:
When a ligament or tendon becomes detached from associated bone, surgery usually is required to re-secure the ligament or tendon. Often, a substitute ligament, or graft, is attached to the bone to facilitate re-growth and permanent attachment. Various methods of ligament graft attachment are known, including staples, suture over buttons, and interference screw fixation.
Various problems exist with the known fixation methods. Staples and suture buttons are disadvantageous because they often do not provide fixation sufficient to withstand the normal tensile loads. With suture button fixation, for example, a strand of suture couples the button and the substitute ligament. This strand becomes the "weakest link in the chain," and if the strand breaks, the ligament detaches.
A stronger graft attachment can be obtained by interference screw fixation, whereby an interference screw is used to wedge a graft bone block to the wall of a graft tunnel. See, e.g., U.S. Pat. Nos. 5,211,647, and 5,603,716, incorporated herein by reference.
Although interference screw attachment is more secure than using staples or suture buttons, it is sometimes neither possible nor desirable to provide such fixation, particularly in the femoral tunnel. In revision situations, for example, where a previous reconstruction has been performed, placing a second femoral tunnel close to the previous tunnel may not be indicated.
In other cases, a semitendinosus graft must be used because the previous reconstruction used the mid third patellar tendon. Although a bone-semitendinosus graft-bone construct may be prepared using a workstation as disclosed in U.S. Pat. No. 5,397,357, such a procedure is time consuming, and may be undesirable for other reasons.
A fixation technique which provides strong attachment of a semitendinosus graft in the femoral tunnel, using a transverse pin, is disclosed in U.S. Pat. No. 5,601,562, of common assignment with the present application. The transverse pin is inserted through a loop in a tendon graft. A threaded portion of the pin screws into the bone as the pin is advanced with rotation into the repair site. The technique is disadvantageous, however, because the graft can wrap around the pin as it is rotated. An improved loading technique is the subject of a co-pending U.S. patent application, attorney docket no. P/1493-147, which also claims the benefit of U.S. Provisional Application Ser. No. 60/037,610, filed Feb. 12, 1997.
Various endoscopic techniques and instruments relating to graft fixation are known in the prior art and can be used in the practice of the present invention as it relates to graft repair of knee ligaments, as follows: U.S. Pat. No. 5,320,636 to Schmieding discusses an endoscopic drill guide for graft tunnel location. U.S. Pat. No. Des. 378,780 illustrates a cannulated headed reamer as can be used in femoral socket formation. U.S. Pat. Nos. 5,269,786 and 5,350,383 disclose drill guides for location of bone tunnels.
The need exists for fixation devices that can be installed without rotation, and yet are removable.


To provide a mechanical seal in which degradation or tearing of a bellows does not occur, the spring constant of the bellows is reduced, and the fluctuation in the load due to stretching and contracting of the bellows is reduced. An inside-type mechanical seal includes a sleeve fixed to a rotating shaft, and a cartridge fixed to a housing. A rotation-side sealing ring is provided to the sleeve. A fixed-side sealing ring, which slides against the rotation-side sealing ring, and a bellows for axially urging the fixed-side sealing ring is provided to the cartridge. The bellows is made from a metal; and the metal bellows has one end fixed to a case for holding the fixed-side sealing ring and another end fixed to the cartridge. The plate thickness of the metal bellows is set so as to be smaller than the plate thickness of the case or the cartridge.

One conventionally known type of a mechanical seal is, as shown in FIG. 7, an inside-format mechanical seal in which a sealed fluid that may leak from the outer circumference of a sealing face to the inner circumference direction is sealed, wherein: an annular rotation-side sealing ring 53 provided, via a sleeve 51 and a cup gasket 52, on the side of a rotating shaft 50 for driving a pump impeller (not shown) on the high-pressure fluid-side, so as to be capable of rotating integrally with the rotating shaft 50; and an annular fixed-side sealing ring 55 provided, via a bellows 57 in a cartridge 56, to a housing 54 Document of the pump in a non-rotating state so as to be capable of axial movement, are caused by the bellows 57 and a coiled wave spring 58 axially urging the fixed-side sealing ring 55 to slide against each other in intimate contact at respective sealing faces S which have been mirror-surface-finished by lapping or the like (hereafter referred to as "prior art 1"; see, e.g., Patent Document 1). The bellows 57 in the mechanical seal in this prior art is made from rubber, and has one end attached to the fixed ring 55 via a case 59 and the other end attached to a cartridge inner cylinder part 56 via a driving band 60.
Patent Document 2 discloses an invention of a mechanical seal in which, as shown in PIG. 8, a fixed-side sealing ring 62 is attached to a housing 61, a rotation-side sealing ring 63 is provided to a shaft which is rotatably supported by the housing 61, and the fixed-side sealing ring 62 and the rotation-side sealing ring 63 are in elastic contact with each other so as to be capable of sliding, wherein a fixing claw 64a is formed on the right end of a metal bellows 64 so that the metal bellows 64 supports the fixed-side sealing ring 62 so as to be capable of axial movement, the fixing claw 64a is bent and the fixed-side sealing ring 62 is supported at the right-end interior of the metal bellows 64, and the left end of the metal bellows 64 is directly fixed to the housing 61 (hereafter referred to as "prior art 2"; see Patent Citation 2).
However, in prior art 1, the bellows 57 being made from rubber presents problems such as degradation or tearing of the bent part. Problems are also presented in that an urging member such as the coiled wave spring 58 and an attaching member such as the driving band 60 are required, increasing the number of components.
In prior art 2, since the structure is one in which the fixed ring 62 is directly supported by the metal bellows 64 and the metal bellows 64 is directly fixed to the housing 61 such that the metal bellows 64 functions also as a cartridge, a problem is presented in that the metal bellows 64 must have the same thickness as that of a cartridge or a case, resulting in an increase in the spring constant of the metal bellows 64,


A rotor, such as a rotor of an aircraft gas turbine engine, uses damper-ring devices for damping unwanted rotor vibrations. One device has inner and outer damper rings with the outer damper ring providing ring-rotor frictional damping only at large vibrational amplitudes and with the inner and outer damper rings providing inter-ring frictional damping at both small and large vibrational amplitudes. Other devices include a damper ring and a viscoelastic layer, a hollow damper ring containing particulate matter, and a damper ring in the form of a cable made of twisted single-wire strands.

The present invention relates generally to rotors, and more particularly to damping unwanted rotor vibrations.
Rotors are the rotatable portions of rotary machines, and rotary machines include, without limitation, X-ray tubes, a centrifugal compressor, a steam turbine (including a turbine portion thereof) used by a power utility company, and a gas turbine (including a compressor portion or a turbine portion thereof) used as an aircraft engine or used by a power utility company.
It is known to dampen vibrations of a rotor of an aircraft gas turbine engine by installing a split-ring damper in a damper-ring groove of the rotor. The rotor may include rotor blades attached to, and extending radially-outward from, a shaft, or the rotor may be a monolithic blisk having shaft and blade portions. The damper-ring groove is a circumferential, radially-inward-facing groove on the shaft or shaft-portion of the rotor with the groove being coaxially aligned with the longitudinal axis of the rotor. To prevent longitudinal motion of the split-ring damper, the groove may have two longitudinally-spaced-apart side walls or, in the case of a tapered shaft, the groove may have a single side wall. The split-ring damper is a metallic ring having a single, radially-aligned through-cut. The weight, flexibility (Young""s modulus), and surface friction characteristics of the split-ring damper are chosen (by experiment, computer analysis, and/or closed-form equations) to provide the most damping for a particular amplitude of one rotor vibrational mode of one natural vibrational frequency which typically corresponds to an expected maximum amplitude of a dominant vibrational mode of an excitation frequency which is closest to steady-state rotor operation. The split-ring design of the damper provides ease of installation in the damper-ring groove and allows frictional damping (by microslippage) between the outer circumferential surface of the split-ring damper and the rotor. Such damping is less effective or ineffective to dampen vibrations below the expected maximum amplitude, such as small-amplitude vibrations which may lead to fatigue failure of the rotor. What is needed is improved rotor damping.
In a first embodiment of the invention, apparatus for damping a rotor includes at least a first and a second damper ring wherein the outer diameter of the second damper ring is generally equal to the inner diameter of the first damper ring. In a second embodiment, a rotor assembly includes a rotor having a damper-ring groove and includes the previously-described at least first and second damper rings positioned in the damper-ring groove. A first expression of a method of the invention obtains and positions the previously-described at least first and second damper rings in the damper-ring groove of a rotor.
In a third embodiment of the invention, apparatus includes a damper-ring assembly having an inner damper ring, an outer damper ring, and a viscoelastic layer positioned radially between and bonded to the inner and outer damper rings. In a fourth embodiment, a rotor assembly includes a rotor having a damper-ring groove and includes the previously-described damper-ring assembly positioned in the damper-ring groove.
In a fifth embodiment of the invention, a rotor assembly includes a rotor having a damper-ring groove and includes a damper-ring assembly positioned in the damper-ring groove, wherein the damper-ring assembly has an outer damper ring and has a viscoelastic layer positioned radially between and bonded to the outer damper ring and the rotor.
In a sixth embodiment of the invention, a damper ring includes a generally ring-shaped housing having a hollow portion and includes particulate matter located within the hollow portion of the housing. In a seventh embodiment, a rotor assembly includes a rotor having a damper-ring groove and includes the previously-mentioned damper ring disposed in the damper-ring groove.
In an eighth embodiment of the invention, apparatus includes single-wire strands twisted together to define a cable, wherein the cable has a shape of a split ring. In a ninth embodiment, a rotor assembly includes a rotor having a damper-ring groove and includes the previously-described cable positioned in the damper-ring groove.
Several benefits and advantages are derived from the invention. The known single-ring design of the prior art provides frictional damping between the outer circumferential surface of the ring and the rotor only for large-amplitude vibrations. In an at-least-two-ring embodiment of the invention, the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring undergo microslippage and hence frictional damping in response to small-amplitude vibrations, and, for large-amplitude vibrations, there is added thereto the frictional damping of the outer circumferential surface of the outer ring with the rotor. Engineering analysis shows that dividing one ring into two or more concentric rings (of the same total weight as the one ring) provides more damping over a larger range of vibrational amplitudes than does the one ring. In a viscoelastic-layer embodiment of the invention, the viscoelastic layer provides damping in the form of viscous damping for smaller-amplitude vibrations, and, for larger-amplitude vibrations, there is added thereto the frictional damping of ring-rotor contact or ring-ring contact. In a hollow-damping-ring embodiment of the invention, the particulate matter provides particulate frictional damping for smaller-amplitude vibrations, and, for larger-amplitude vibrations, there is added thereto the frictional damping of the ring""s housing with the rotor. In a cable embodiment of the invention, the twisted single-wire strands provide frictional damping between strands for smaller-amplitude vibrations, and, for larger-amplitude vibrations, there is added thereto the frictional damping of the cable with the rotor.


There is provided a piezoelectric transformer including (a) a cylindrical body made of piezoelectric material and longitudinally defining a driven section and a voltage generating section, the voltage generating section being polarized in one of directions in a direction of a longitudinal axis of the cylindrical body, (b) a pair of first electrodes formed at a curved surface of the cylindrical body in the driven section and defining a plurality of regions in the driven section in a direction of a longitudinal axis of the cylindrical body, the first electrodes being electrically isolated with each other, the regions being polarized so that every other regions are polarized in opposite directions in a direction of a longitudinal axis of the cylindrical body, the pair of first electrodes comprising a plurality of strip-shaped electrodes wound around the cylindrical body and disposed in parallel with one another in a direction of a longitudinal axis of the cylindrical body, every other strip-shaped electrodes being in electrical communication with one another so that they have a common voltage, and (c) a second electrode cooperating with one of the first electrodes located closer to the voltage generating section to make a pair therewith. In accordance with the above mentioned piezoelectric transformer, it is possible to prevent edges of a piezoelectric body from being chipped, because of its cylindrical shape. Thus, it is also possible to prevent destruction of a transformer originated from chipping thereof, resulting in higher reliability of a piezoelectric transformer.

1. Field of the Invention
The invention relates to a piezoelectric transformer, and more particularly to a piezoelectric transformer formed at a surface thereof with input and output electrodes. The invention relates also to a support for a piezoelectric transformer.
2. Description of the Prior Art
There has been widely used a coil-wound type electromagnetic transformer as a transforming device for generating a higher voltage to be used for equipments which requires a high voltage, such as a deflector for a cathode ray tube and a charging device for a copier.
On the other hand, a piezoelectric transformer utilizing piezoelectric effect becomes popular for generating a high voltage. FIG. 1A illustrates one of conventional piezoelectric transformers. The illustrated piezoelectric transformer includes a rectangular planar piezoelectric body 131 defining a driven section 135 and a voltage generating section 136 in a direction of a longitudinal axis of the piezoelectric body 131. The piezoelectric body 131 is formed on an upper surface in the driven section 135 with a first electrode 132, and on a lower surface with a second electrode 133 in alignment with the first electrode 132. The first and second electrodes 121 and 133 are electrically insulated with each other, and it is possible to apply a voltage thereacross.
The piezoelectric body 131 is formed at an end surface in the voltage generating section 136 with a third electrode 137. The piezoelectric body 131 including the three electrodes 132, 133 and 137 is polarized in a widthwise direction thereof in the driven section as indicated with an arrow X1, and polarized in a lengthwise direction thereof in the voltage generating section 136 as indicated with an arrow X2. The piezoelectric transformer is supported and fixed on a support 139 at the center in a direction of a longitudinal axis thereof.
In order to boost a voltage by means of the illustrated piezoelectric transformer, an ac voltage Ein is first applied across the first and second electrodes 132 and 133. The ac voltage Ein is selected to have a frequency equal to a resonance frequency of a longitudinal oscillation of the piezoelectric body 131. By applying the thus selected ac voltage across the first and second electrodes 132 and 133, the piezoelectric body 131 is mechanically resonated, resulting in that a voltage Eout which is higher than Ein and has the same frequency as that of Ein is generated at the voltage generating section 136. The thus generated higher voltage Eout can be obtained between the second (or first) electrode 133 and the third electrode 137. The support 139 supports the piezoelectric transformer at a nodal point of longitudinal oscillation of the piezoelectric body 131.
The above mentioned operation concerns only voltage step-up. By substituting the first and second electrodes 132 and 133 used as input ports and the third electrode 137 used as an output port with each other, that is, by applying an ac voltage across the second and third electrodes 133 and 137 and obtaining a voltage between the first and second electrodes 132 and 133, the illustrated piezoelectric transformer acts also as a step-down transformer. It depends on the purpose of using the piezoelectric transformer whether electrodes formed on a surface of a piezoelectric body are used as input or output electrodes, and whether sections defined in a piezoelectric body are used as driven or voltage generating sections.
In order to put the above mentioned piezoelectric transformer illustrated in FIG. 1A to practical use, it is necessary to provide the first to third electrodes 132, 133 and 137 with a terminal such as a lead wire for electrically connecting the piezoelectric transformer to an external circuit. However, such lead wires are not always connected to the electrodes 132, 133 and 137 both in the driven and voltage generating sections 135 and 136 at nodal points of mechanical oscillation of the piezoelectric body 131. Thus, the lead wires connected to the electrodes are often broken down. In order to enhance reliability in connection between the surface electrodes and the lead wires, it is effective that lead wires are connected to surface electrodes at nodal points of oscillation of a piezoelectric body. To this end, there are often defined three sections in a piezoelectric body.
FIG. 1B illustrated an example of a piezoelectric transformer having a piezoelectric body 141 including three sections defined therein in a direction of a longitudinal axis thereof. Namely, the piezoelectric body 141 includes a left side driven section 145L, a right side driven section 145R, and a voltage generating section sandwiched the driven sections 145L and 145R. The voltage generating section is partitioned into two sections 146L and 146R by a strip-shaped electrode 147 wound around the piezoelectric body 141 at a longitudinal midpoint of the piezoelectric body 141. Thus, the piezoelectric body 141 includes four sections: the left side driven section 145L, left side voltage generating section 146L, right side voltage generating section 146R and right side driven section 145R, which sections are arranged symmetrically about the electrode 147. The piezoelectric body 141 is formed on upper and lower surfaces thereof in the left side driven section 145L with input electrodes 142L and 143L. Similarly, the piezoelectric body 141 is formed on upper and lower surfaces thereof in the right side driven section 145R with input electrodes 142R and 143R. The driven sections 143L and 143R are polarized in a thicknesswise direction of the piezoelectric body 141, as indicated with an upwardly directed arrow X1. The voltage generating sections 146L and 146R are polarized in a lengthwise direction of the piezoelectric body 141, similarly to the piezoelectric transformer illustrated in FIG. 1A, but in opposite directions, as indicated with arrows X2 and X3. That is, the left side voltage generating section 146L is polarized to the left in a direction of a longitudinal axis of the piezoelectric body 141, as indicated with the arrow X2, whereas the right side voltage generating section 146R is polarized to the right in a direction of a longitudinal axis of the piezoelectric body 141, as indicated with the arrow X3. The upper input electrodes 142L and 142R are electrically connected by a wire W1, and the lower input electrodes 143L and 143R are electrically connected by a wire W2. An ac voltage Ein is applied across the upper input electrodes 142L and 142R and the lower input electrodes 143L and 143R through the wires W1 and W2. An output voltage Eout, which is higher than Ein, is obtained between the electrode 147 and the upper input electrodes 142L and 142R. The ac voltage Ein is selected to have a frequency which causes tertiary resonance in a direction of a longitudinal axis of the piezoelectric body 141. By applying the thus selected ac voltage Ein to the electrodes, the piezoelectric body 141 has three nodal points in oscillation thereof: a point A1 at a distance of one-sixth of a full longitudinal length L of the piezoelectric body 141 away from an end surface 14a of the piezoelectric body 141; a point A2 at a distance of one-sixth of the length L away from the other end surface 141b of the piezoelectric body 141; a point A3 located at the midpoint of the length L. Thus, it is possible to prevent break-down of lead wires due to oscillation of the piezoelectric body 141 by connecting the lead wires to the surface electrodes 142L, 143L, 142R, 143R and 147 at the nodal points A1, A2 and A3.
The planar piezoelectric transformers as mentioned above is small in size, but can produce a high voltage, and hence is very attractive, for instance, to an invertor to be used for a liquid crystal back light, which is requested to be smaller in size. However, the planar piezoelectric transformers still have the following problems to be solved which are accompanied by the fact that a piezoelectric transformer is planar.
The first problem is as follows. When a piezoelectric body is oscillated, a larger internal stress is generated in the vicinity of nodal points of oscillation in the piezoelectric body. Specifically, tensile stresses are produced at a boundary between the driven section 135 and the voltage generating section 136 in the piezoelectric transformer illustrated in FIG. 1A and in the vicinity of the electrode 147 in the piezoelectric transformer illustrated in FIG. 1B, respectively, and thus the piezoelectric bodies 131 and 141 are in conditions to be readily destructive. A piezoelectric transformer is usually designed so that the tensile stress is lower than a critical value for destruction of a piezoelectric body. However, ceramic of which a piezoelectric body is often made is likely to be chipped even by small impact, and a chipping has occurred once in a piezoelectric body, the critical value is significantly lowered, resulting in that a piezoelectric body is easily destroyed.
A chipping as mentioned above in a piezoelectric body is unavoidable in piezoelectric body fabrication steps and subsequent steps, and hence is a major factor for preventing enhancement in reliability to a piezoelectric transformer. In addition, a piezoelectric body has to be treated with the greatest possible care, which increases fabrication costs of a piezoelectric transformer. A chipping, reduction in reliability due to a chipping, and increased fabrication costs as mentioned above are problems in particular when a piezoelectric body is formed in a rectangular parallelopiped such as a plate and a prism. This is because a rectangular parallelopiped has many edges at which a chipping is prone to take place.
The second problem of a planar piezoelectric transformer is that noises tend to be produced in audible ranges. Since a piezoelectric transformer utilizes mechanical oscillation, a frequency for operation of a piezoelectric transformer is selected to be in the range of about 30 to about 150 kHz which is beyond audible range. In a planar piezoelectric transformer, there would be generated longitudinal oscillation in a widthwise direction, bending oscillation and torsional oscillation as well as longitudinal oscillation in a direction of a longitudinal axis of a piezoelectric body. Thus, frequencies of those oscillations, a beat frequency between two different oscillations, and a beat frequency between higher mode frequency of various oscillations and another mode frequency enter audible range. Such frequencies entering audible range would be merely a noise to men's ears, which poses a problem in putting a planar piezoelectric transformer into practical use. Even if a piezoelectric transformer is fabricated in the form other than a plate, there would be produced various oscillation modes. However, a piezoelectric transformer fabricated in the form of a planar plate would quite readily produce unpreferable modes of oscillation, which oscillation in addition is likely to become greater in level.
In order to solve the above mentioned problems caused by the fact that a piezoelectric body is planar in shape, there has been suggested piezoelectric bodies in various forms.
U.S. Pat. No. 2,974,296 has suggested a columnar piezoelectric transformer. The piezoelectric transformer has a thin-walled columnar piezoelectric body defining three sections in a direction of a longitudinal axis thereof. Ring-shaped electrodes are wound around the piezoelectric body at boundaries among the three sections and at opposite ends. Among the four electrodes disposed longitudinally of the piezoelectric body, two of the internally located electrodes are used as driven electrodes, whereas two of the externally located electrodes are used as voltage generating electrodes. Since it is difficult in the above mentioned piezoelectric transformer to make a step-up ratio greater, which is defined as a ratio of an input voltage to an output voltage, U.S. Pat. No. 2,974,296 has also suggested a piezoelectric transformer including a driven section defined between outer and inner surfaces of a piezoelectric body, and a voltage generating section defined over a full length of a piezoelectric body.
Japanese Unexamined Patent Publication No. 2-311181 has suggested a columnar piezoelectric motor including cross type finger electrodes.
Japanese Unexamined Patent Publication No. 2-163982 has suggested a piezoelectric actuator including electrodes spirally extending on an outer surface thereof.
Japanese Unexamined Patent Publication No. 4-307322 has suggested a columnar piezoelectric gyro.
The piezoelectric transformer suggested in U.S. Pat. No. 2,974,296 does not have purposes of prevention of chipping in a piezoelectric body and prevention of noises. The above mentioned piezoelectric motor, piezoelectric actuator and piezoelectric gyro are devices used for electrical-mechanical energy conversion or mechanical-electrical energy conversion. In a device such as a motor or a gyro necessarily including mechanical rotation, a piezoelectric body is inevitably columnar in shape. In contrast, a piezoelectric transformer acting as an electrical-mechanical energy convertor may have any shape, but it is not known so far to fabricate a piezoelectric transformer including a cylindrical piezoelectric body.


A system and method of welding is provided where a first welding power supply provides a first welding waveform to a strip electrode for welding a work piece and a second welding power supply provides a second welding waveform to at least one curtain electrode for welding the work piece. The at least one curtain electrode is positioned adjacent to a side of said strip electrode during welding.

Field of the Invention
Devices, systems, and methods consistent with the invention relate to welding with cladding and curtain electrodes.
Description of the Related Art
Cladding with strip electrodes is known in the industry. Typically strip electrodes are used for cladding because of their large width and low penetration resulting in a large cladding area but low admixture with the base metal. This is especially true of electro-slag cladding. However, as the penetration is minimized, there is a risk of lack of penetration or even inclusions at the edges of the clad deposit especially where the deposit intersects with a previous adjacent deposit. If found, these inclusions require repair, if left unchecked, these inclusions can result in premature failure of the cladding layer. Further, when cladding with strip electrodes it is desirable to increase the width of the strip electrode to clad larger areas faster. However wider strip electrodes require significantly more current to apply. These high currents produce magnetic fields that become concentrated at the ends of the strip. These highly concentrated magnetic fields disturb the puddle and can force liquid metal from the edges of the weld deposit toward the center. In extreme cases, electro-magnetic steering devices are used to introduce a counter rotating magnetic fields to cancel some of the adverse affects of concentrated high magnetic fields at the edge of the strip electrode.

Apparatus for welding with curtain electrodes and strip electrodes