The present disclosure provides an improved shaped catalyst containing catalytic material comprised of mixed oxides of vanadium and phosphorus and using such shaped catalysts for the production of maleic anhydride.

Maleic anhydride is a well-known and versatile material for the manufacture of unsaturated polyester resins, chemical intermediates (e.g. butanediol and tetrahydrofuran), pharmaceuticals and agrochemicals. It is produced by partial oxidation of aromatic or non-aromatic hydrocarbons in the gas phase and in the presence of a catalyst. The oxidation reaction may be carried out in a fixed, fluidized, or riser bed reactor.
Catalysts based on vanadium and phosphorus oxides ("VPO catalysts") have been developed for use in the oxidation reaction described above. In particular, VPO catalysts particularly well suited to catalyze the oxidation reactor are those in which the valence of the vanadium is less than +5, usually between about +3.8 and about +4.5.
Conventional methods of preparing these catalysts generally involve reducing a pentavalent vanadium compound, and combining the same with a phosphorus compound, and promoter element compounds if desired, to form a catalyst oxide precursor. The catalyst oxide precursor is then recovered and converted to active catalytic material.
It is generally known that by selecting varied geometrical cross-sectional configurations, formed catalytic particles may be designed to offer shorter diffusion paths for reactants and/or products which may be desirable in reactions like those described above. Additionally, catalytic particle configuration has been employed in the past to reduce the pressure drop encountered across a packed catalyst bed, and/or to reduce catalyst loss due to breakage, abrasion or crushing during storage, handling, sizing or when severe process conditions are encountered.
Therefore, the prior art has suggested many shapes, including rods, cylinders, spheres, spools, etc., of various sizes, dimensions and proportions for VPO catalysts including:
U.S. Pat. No. 4,283,307 which discloses a VPO catalyst in the shape of a small cylinder with a hole therethrough and where the height and diameter of the cylinder are substantially the same;
U.S. Pat. No. 4,656,157 which discloses a VPO catalyst that is in the shape of a hollow cylinder with end faces curved such that the radius of curvature is from 0.4 to 5 times the external diameter;
U.S. Pat. No. 5,168,090 which discloses a VPO catalyst having a solid geometric form (for e.g. cylinder, cube, cone, sphere) with at least one void space disposed in its external surface;
U.S. Pat. No. 6,812,351 which discloses a VPO catalyst having an essentially hollow cylindrical body and a ratio of height to the diameter of the continuous hole of not more than 1.5 and a ratio of geometric surface area to geometric volume of at least 2 mm−1;
U.S. Pat. No. 9,138,729 which discloses a VPO catalyst having an essentially cylindrical body with at least two internal holes parallel to the axis of the cylindrical body;
EP 0220933A1 which discloses a VPO catalyst having a quadrilobe cross-sectional shape; and
U.S. Pat. No. 8,048,820 which discloses a VPO catalyst having a traditional trilobe cross-sectional shape where each lobe is provided with a continuous internal hole.
Although each of the shapes above provide VPO catalysts with appreciable activity and selectivity in the preparation of maleic anhydride, it is desirable to provide improved shaped catalysts which maximize productivity, minimize pressure drop in the reaction system and have sufficient mechanical stability.

Cored round trilobe shaped catalyst for producing maleic anhydride


This is a device to easily and safely transport a toilet, which can be broken down and folded for easy storage and transport. It has very few mechanical parts and uses the existing toilet set holes to safely lift a toilet.

A. Field of the Invention
This relates to the safe transportation of a toilet. Specifically, the device will assist an individual to move a toilet safely from a truck inside a home or business so that the toilet may be installed. The device may also be used to lift a toilet to change the wax ring, which is part of every toilet.
B. Prior Art
There are many other devices, which can transport toilets. Respresentive examples of these devices are Geuvara, U.S. Pat. No. 6,015,137 and Gwynn U.S. Pat. No. 6,685,170.
One of the potential drawbacks of the Gwynn device is that the toilet may actually drop because it is suspended by ropes and hoists. The Geuvara patent uses a strap mechanism, which is controlled by a crank and pulley system and is substantially different than the current mechanism.

Toilet transport device and method to use


A method is disclosed for routing data packets in a wireless network, preferably a Bluetooth™ network. The method includes estimating a link bandwidth of at least one network node, calculating a connectivity metric based on the estimated link bandwidth, distributing information concerning the calculated connectivity metric and, using the calculated connectivity metric, determining a route having a maximum link bandwidth and a minimum traffic load. Preferably, estimating uses a model of a Bluetooth network medium access control MAC algorithm. The connectivity metric is defined as a ratio of a maximum link bandwidth to the estimated link bandwidth, where the maximum link bandwidth is the link bandwidth between a Master node and a Slave node when there is only one Slave node connected to the Master node (i.e., when there is one Slave node in the piconet with the Master node).

The Bluetooth™ (BT) protocol has resulted from the National Telecommunications Act opening new public access to the ultra high frequency (UHF) and very high frequency (VHF) bands. As a direct consequence, wireless local area networking is rapidly evolving as the communications standard for small and mobile corporations and other organizations. An important aspect of these new wireless networks is the integration of household (and business office) appliances, laptop computers, and personal communications service (PCS) devices. This technology, called BT, seamlessly connects each intelligent appliance in a household or an office within a "piconet" (implying a very small) wireless network.
BT is an embedded, low-power, short-range, radio-frequency (RF) technology, although it can also be IR media-based with moderate bandwidth. BT is particularly attractive for exchanging data between personal devices such as cellular phones, radios, pagers, personal digital assistants, notebook computers, video and still cameras, audio players, and local area networks (LANs).
With an operating range of 10 meters or less, the reach of BT exceeds the current range of IR, but falls far short of other types of wireless networks. BT is implemented at 2.4 GHz in the Industrial, Scientific, and Medical (ISM) band.
The BT architecture integrates a combination of hardware and software into the networking device. The hardware is an embeddable module, or a module residing on a card, which interfaces with the host device. It interfaces on one side with the host and on the other side with another BT device via its RF or IR transceiver. On the host side, there are four currently identified interfaces: the universal serial bus (USB), the PC card (or PCMCIA), and two serial interfaces, UART and RS232. All of these have established standards that define the physical and logical interaction. However, the higher level interaction between the BT device and the host is defined in unique BT protocols and packets.
As can be seen in FIG. 1, the software includes salutation and security managers, a database, and the protocol stack. The transport technology is digital packet-oriented communications (rather than analog or streaming digital). Communication with the host includes hardware control and event monitor packet types. Asynchronous connection-oriented (ACO) and synchronous connection-oriented (SCO) packets are used for the link communication between devices, with SCO used primarily for real-time audio and video. Conventional packets, such as the Telephony Communications Service (TCS) and Internet Protocol (IP), are encapsulated in the BT SCO and ACO data packets, adding one more layer to the stack and therefore one more encapsulation with its overhead. Therefore, BT requires an additional protocol stack for a PC. FIG. 1 also presents an example of the required additional protocol stack. The IrDa Object Exchange (OBEX) is required for IR interoperability. Also shown is a wireless network connection to a BT device that transfers data using a User Datagram Protocol (UDP) or a Transmission Control Protocol (TCP).
Protocols, stacks, and the salutation manager provide BT "services". The salutation manager provides both server advertisement and client request capabilities, in addition to the brokering of services, and establishing and then managing the follow-on communication session for the discovery function. The salutation manager is typically independent of the processor operating system and communication protocol. The actual data transfer is under host control via the protocol stack constructed for the data type.
The BT salutation manager has a subordinate security manager, which is invoked when discovery is initiated. The security manager holds service and device security databases. It consults these databases when a request comes in for services. It also submits identifying information when a request for services goes out to another BT device.
The process of service discovery occurs as follows. A client device either attempts to browse another device's server for information, or it requests information about the server. It does this by providing a unique universal identification code. The queried device responds, depending on the security manager's decision, which is based on the device information in its database. If the device is a trusted unit according to the database, the requested information will be returned.
Although BT was originally designed as a replacement for wired connections between devices, it has evolved into a major radio interface candidate for personal area networking and proximity area networking. This is due at least in part to its low power consumption.
The basic unit of the BT piconet can only connect up to eight nodes. As such, technology has been developed that can connect multiple piconets to form a large scale network that is referred to as a scatternet. The scatternet is defined as a group of piconets in which connections exist between different piconets. The node that connects multiple piconets is referred to as a PMP (Participant in multiple piconet) in the BT specification. There are two types of PMP nodes. A PMP node that attends multiple piconets simultaneous only as a slave can be referred to as a S/S PMP, while a PMP node that attends multiple piconets simultaneously, and has a master role in one of the piconets, can be referred to as a M/S PMP.
The standardization activity with regard to personal area networks is discussed in the BT PAN Working group. The current BT Personal Area Network (PAN) profile only supports packet forwarding within one piconet. Issues regarding scattemet communication, such as how to switch between piconets (referred to as Inter-Piconet Switching, or IPS), and how to form a multi-hop network (referred to as Network Formation), and how to route packet within a scatternet (referred to as PAN routing) are still under discussion.
In general, it is a challenging task for a Bluetooth™ network to provide an ad hoc communication mechanism. This is due to the fact that Bluetooth™ has a very distinct medium access control (MAC) layer protocol that is optimized for short-range, point-to-point communication. On the other hand, many mobile ad hoc routing protocols have been proposed, such as one known as AODV (Ad Hoc On-Demand Distance Vector, see, for example, Mobile Ad Hoc Networking Working Group, Internet Draft, 22 Apr. 2000, Ad Hoc On-Demand Distance Vector (AODV) Routing", Charles E. Perkins et al.)
The basic concept of AODV is that the originator of a conversation broadcasts a Route Request (RREQ) message to search for its destination; and the node that knows the route to that destination replies to the RREQ message with a Route Reply message. The originator then selects one route for packet forwarding based on the received reply or replies.
More specifically, AODV builds routes using a route request/route reply query cycle. When a source node desires a route to a destination for which it does not already have a route, it broadcasts a route request (RREQ) packet across the network. Nodes receiving this packet update their information for the source node and set up backwards pointers to the source node in the route tables. In addition to the source node's IP address, current sequence number, and broadcast ID, the RREQ also contains the most recent sequence number for the destination of which the source node is aware. A node receiving the RREQ may send a route reply (RREP) if it is either the destination or if it has a route to the destination with corresponding sequence number greater than or equal to that contained in the RREQ. If this is the case, it unicasts a RREP back to the source. Otherwise, it rebroadcasts the RREQ. Nodes keep track of the RREQ's source IP address and broadcast ID. If they receive a RREQ which they have already processed, they discard the RREQ and do not forward it.
As the RREP propagates back to the source, nodes set up forward pointers to the destination. Once the source node receives the RREP, it may begin to forward data packets to the destination. If the source later receives a RREP containing a greater sequence number, or one containing the same sequence number with a smaller hop count, it may update its routing information for that destination and begin using the better route.
As long as the route remains active, it will continue to be maintained. A route is considered active as long as there are data packets periodically traveling from the source to the destination along that path. Once the source stops sending data packets, the links will time out and eventually be deleted from the intermediate node routing tables. If a link break occurs while the route is active, the node upstream of the break propagates a route error (RERR) message to the source node to inform it of the now unreachable destination(s). After receiving the RERR, if the source node still desires the route, it can reinitiate route discovery.
AODV maintains routes for as long as the route is active. This includes maintaining a multicast tree for the life of the multicast group. Because the network nodes are mobile, it is likely that many link breakages along a route will occur during the lifetime of that route.
Most conventional routing algorithms use a number of hops to find the best route in the network. However, such multi-hop routing protocols, if implemented in a Bluetooth™ network directly, will be very inefficient, as they do not consider the Bluetooth™ network characteristics, e.g., the fact that the traffic in a Bluetooth™ network is centralized on the architectural model of the Master node and the PMP (Participant in Multiple Piconet) node.
In general, in most typical piconets the Master node does not communicate with any one particular Slave node using the maximum data transfer speed, as it is required to also service other Slave nodes. Furthermore, since the PMP node needs access to multiple Master nodes in multiple piconets, a PMP-Master link cannot provide as great a bandwidth as a Master-Slave link. The end result is that the Master and PMP nodes have a smaller degree of freedom to provide a wider bandwidth link. For example, if one were to count either the Master-Slave link or the Master-PMP link as one hop, one may select a route that passes through a heavily loaded link, while bypassing a route with sufficient bandwidth resources and a relatively light load.
As was discussed above, the existing ad hoc routing protocols do not consider the characteristics of the Bluetooth™ network. For example, they view all Bluetooth™ nodes as nodes having similar load and bandwidth capacities, and they count either the Master-Slave link or the Master-PMP link as one hop when performing a route search.
On the other hand, some existing quality of service (QoS) routing protocols do determine a maximum bandwidth route, but they do so by sharing link bandwidth information between nodes. This approach thus requires a node to use its scarce bandwidth resource for exchanging the link bandwidth-related information. Furthermore, the use of this approach may be problematic in a Bluetooth™ network, since a Bluetooth™ node's link bandwidth is typically constantly varying due to radio interference and possibly other factors. This makes it difficult or even impractical to measure and exchange the link bandwidth data in real time.
Based on the foregoing it can be appreciated that problems exist with regard to applying current routing protocols to a Bluetooth™ network as, for example, the routing protocol may not bypass a node with a small bottleneck bandwidth or heavy load, and may miss finding a better route with a larger bottleneck bandwidth or lighter load.

Bluetooth personal area network routing protocol optimization using connectivity metric


Disclosed is an apparatus for automatic playing of a musical instrument. This apparatus has holding means for holding pedal play information that is included in play information that is read from storage means. During a fast forward or a fast reverse operation, the apparatus for automatic playing of a musical instrument holds in the holding means the most recent history of pedal play information, and when the operation is released, and in advance of the execution of play information for keys, the apparatus drives a pedal terminal in consonance with the retained pedal play information, and then reproduces music.

1. Field of the Invention
The present invention relates to an apparatus for automatic playing of a musical instrument, an apparatus that plays music on demand by using prerecorded play information, which is held in a storage device, to control the performance of a musical instrument.
Apparatuses for automatic playing of musical instruments, which are attached to, for example, pianos, are in current, practical use. To produce music, these apparatuses use prerecorded play information to operate drive mechanisms that manipulate keyboards or pedals.
In addition to normal playing functions, presently employed playing apparatuses ordinarily have a function for accelerating musical progression (hereafter referred to as "fast forward"), and another function for accelerating musical retrogradation (hereafter referred to as "fast reverse").
As fast forward and fast reverse differ drastically from normal playing functions, and possess the potential to adversely affect the quality of music, reproduction fidelity demands that special care be taken to ensure that melodic content is not degraded when fast forward and fast reverse are used.
2. Description of the Related Art
A conventional apparatus for automatic playing of a musical instrument incorporates a storage device, e.g., a floppy disk, that holds play information, including, for example, key numbers, key depression force and time information. When the apparatus receives a signal to begin playing, via, for example, an operation panel, it reads play information from the storage device and uses this information in its operation of the musical instrument.
More specifically, play information constituting event information groups is previously stored in a storage device. As shown by the example in FIG. 4, one event information group consists of an identification symbol, a key number, key depression force, and time information.
When playing is initiated, one event information group of the play information is read from the storage device, and the included time information is examined. When the time information corresponds to an execution timing (time) for the read-out event information, procedures for this event are performed, i.e., keys are depressed or released.
After the procedures for one event information group have been completed, the next event information group is read from the storage device, and the described process is repeated. Music is produced by repeatedly reading and processing event information groups.
The execution time for an event information group is determined as follows: A time count, which is held by a time counter that counts clock cycles, is compared with the time information in the read-out event information group, and when they correspond, it is assumed that the procedures for the event should be performed.
Besides the above described normal playing functions, a conventional apparatus for automatic playing of a musical instrument has fast forward and fast reverse functions. There are two well-known methods for performing fast forward or fast reverse that are used when either the fast forward function or the fast reverse function is selected.
To perform fast forward or fast reverse using the first method, the speed of the clock that governs the operation of the time counter is increased to greater than that for normal reproduction. The performance of the time counter is thereby accelerated, and the execution time for the procedures of the current event information group is advanced.
When fast forward or fast reverse is performed using the second method, the clock speed is not increased and the performance of the time counter is not accelerated. Instead, to speed up performance and to determine an advanced execution time, predetermined multiples of the time count held by the time counter are compared with the time information of the most recently read event information group.
As an automatic playing apparatus that includes a drive mechanism cannot adequately cope with high speed execution, and as the directional order of ON events and succeeding OFF events is inverted when fast reverse is performed, such an automatic playing apparatus usually does not activate operation terminals when either fast forward or fast reverse is selected.
More specifically, when fast forward or fast reverse is selected, all operation terminals, which include a keyboard terminal and a pedal terminal that are being driven, are set to OFF, and fast forward or fast reverse is immediately thereafter begun.
After the fast forward or the fast reverse has been completed, and until the next pedal play information is processed, the pedal terminal is maintained in the OFF state, as it was set when the fast forward or the fast reverse was selected.
Suppose, then, that the first pedal play information to be processed after playing is resumed is OFF event information. Although the state of an event must be 0N during the period between the resumption of normal play and the point at which pedal play information is processed, as the pedal terminal has not been activated the actual event state during this period is OFF, and music quality is thereby significantly impaired.
The shortcomings associated with fast forward and fast reverse operations will be explained in more detail referring to FIG. 5 (fast forward phase) and FIG. 6 (fast reverse phase).
FIG. 5 is a diagram for explaining a fast forward operation. Pedal play information is represented by the identifiers e1 to e8. The several intervals between the identifiers e1 to e8 are occupied by keyboard play information, but such information is not shown here.
In the interval between el and e2 a pedal terminal is being driven (ON period), and in the interval between e2 and e3 a pedal terminal is not activated (OFF period). The succeeding ON/OFF states are as shown in the lower level in the diagram.
If fast forward is begun at point A and is released at point B, music is immediately reproduced at point B.
Although the pedal terminal should be activated in the interval between e5 and e6, as shown in FIG. 5, because of the fast forward selection, as described above, the pedal terminal is actually in the OFF state, and music reproduced during this interval is significantly impaired.
FIG. 6 is a diagram for explaining a fast reverse operation. Pedal play information is represented by the identifiers e11 to e18. The several intervals between the identifiers e11 to e18 are occupied by keyboard play information, but such information is not shown here.
In the interval between e11 and e12 the pedal terminal is being driven (ON period), and in the interval between e12 and e13 the pedal terminal is not activated (OFF period). The following ON/OFF states are as shown in the lower level in the diagram.
If normal playing is started at point C and fast reverse is selected at point D, to perform fast reverse, play information is read out toward point E at faster than the normal playing speed. Then, when fast reverse is released at point E, music is immediately reproduced there.
Although the pedal terminal should be activated in the interval between e11 and e12, as shown in FIG. 6, because of the fast reverse selection, as described above, the pedal terminal is actually in the OFF state, and music reproduced during this interval is significantly impaired.
When a pedal terminal is, for example, a damper pedal of a piano, the period during which music is degraded spans several seconds, sometimes several tens of seconds.

Apparatus for automatic playing of a musical instrument


An apparatus including a combination possibility calculation unit to calculate a stable orientation in which, from three-dimensional shape data of a part, the part is stabilized on a flat surface, to calculate a grasping method for grasping the part with a hand, and to calculate a combination in which the hand does not interfere from system configuration data including information on a connection destination of the hand and a combination group of the grasping method and the stable orientation; a regrasping path calculation unit to calculate a regrasping path of the part by using the calculated combination; a path group calculation unit to calculate a path having the minimum number of teaching points from the regrasping path as a path group based on orientation data for designating an input orientation and an alignment orientation of the part; and a program generation unit to generate a program of a robot based on the path group.

As a conventional method for generating a program for an industrial robot, a method of outputting a robot program of three-dimensionally measuring a movement path of parts demonstrated by the operator, and moving parts along the movement path is known. At the time of program output, in consideration of the physicality of the robot, it is also determined whether the path can be achieved. In addition, when it is not possible to achieve movement with a single robot, regrasping with a plurality of arms is also output as a candidate for a program (Patent Document 1).
There is also known a method for generating a program for searching for a movement path of parts in a two-dimensional plane. The work area is expressed in two dimensions viewed from above, and divided into areas of appropriate size. The initial position and the final position of parts are selected from the divided areas. The reachability of the robot arm is determined in each area, and the area, reachable by the robot arm, continuous from the initial position to the final position is extracted as a movement path. When the movement path cannot be found by one robot arm, regrasping of parts are performed between a plurality of robot arms (Patent Document 2).

Apparatus and method for generating robot program


A method and an apparatus for folding and interfolding single-ply webs, in which single-ply webs are first-folded alternately on their respective lines, tail portions and head portions of the webs are overlapped alternately while reducing the feeding distance of the webs which are already first-folded on their respective lines, and the overlapped webs are second-folded alternately.

1. Field of the Invention
This invention relates to a method and an apparatus for producing wiping webs such as, for example, paper towels or paper tissues which are stored in a container in such a manner as to be able to be taken out consecutively, and particularly to single-ply webs which can be properly taken out of a container.
2. Brief Description of the Prior Art
In conventional paper towels often located at toilet rooms for daily household use such as shown in FIG. 4A, each stack of thick web segments 1 (which are folded in such a manner as head portions a and tail portions b face to face closely or touch each other) are stored in a container. The stack of folded web segments are applied pressure by a spring mechanism 2 so that the head portion a or tail portion b of the web segment 1 at the bottom is pressed against a dispensing port 3 and taken out of the container one by one.
On the other hand, in conventional paper tissues such as shown in FIG. 4B, cut and interfolded thin web segments 1 are piled up and stored in a container, and either of the two end portions b of the web segments is served as a dispensing flap. When an end portion b of the top web segment 1 is pulled out of the container through a dispensing port 3, a subsequent end portion b sticks out of the container one by one.
In the case of the conventional paper-towel serving methods as shown in FIG. 4, each paper towel cannot be taken out very easily one by one, because each dispensing flap a or b does not automatically stick out of the dispensing port one by one. Even if the dispensing port 3 is situated at the bottom of the container so that the dispensing flap a or b can, hopefully, stick out of the dispensing port by its own weight one by one, the dispensing flaps do not always sufficiently stick out of the port as expected. Also, the dispensing flap of FIG. 4A tends to be torn when the end portion b of the web 1 is pinched by fingers and pulled out with a jerk.
One way to hopefully elude this problem is to fold each web segment once and then alternately interfold each flap of the folded web segments as shown in FIG. 4B. The problem (tear of web), however, cannot be entirely eliminated in this case either, although the problem is somewhat eluted when two-ply webs are used for the material sheet. However, in the case of the paper towels, where single-ply webs are folded once but not interfolded, the problem of tear of web cannot be eluted by the method of FIG. 4B. In the case of the paper tissues where a single-ply thin paper is used for the material paper, it is more difficult to employ the method of FIG. 4B.
Thus, it has been desired that an innovative and commercially practicable method and apparatus for converting sheet materials in such a way as shown in FIG. 4C be contrived as an improvement of the conventional paper conversion technologies.
After repeated studies and trials, this inventor has finally succeeded in developing such an innovative and commercially practicable method and apparatus as described hereunder.

Method and apparatus for folding and interfolding single-ply webs


A photoelectric conversion apparatus has: a plurality of pixels having mutually different color filters, and generating pixel signals by a photoelectric conversion; a color selecting switch for selecting the pixel signals generated by the plurality of pixels having mutually different color filters; a first amplifier circuit for amplifying at mutually different gains the pixel signals generated by the pixels having mutually different color filters and selected by the color selecting switch; a reference voltage connecting switch for selecting a reference voltage; and a second amplifier circuit for amplifying at mutually different gains the reference voltages correspondingly to the pixel signals of mutually different colors.

1. Field of the Invention
The present invention relates to a photoelectric conversion apparatus which is used in a scanner, a video camera, a digital camera, or the like.
2. Description of the Related Art
In recent years, there is such a tendency that a high speed is required in a photoelectric conversion apparatus. The method disclosed in the Official Gazette of Japanese Patent Application Laid-Open No. 2010-199710 (Patent Literature 1) is mentioned as one of units for realizing the high speed. According to Patent Literature 1, by using such a circuit construction that pixel signals of the same color are read out in parallel from a plurality of common output lines and color signals of a plurality of colors are read out from each common output line for one horizontal scanning period, a light weight of common output line capacitors is realized, thereby improving speed performance.
According to Patent Literature 1, a point that an amplifier unit is provided for each pixel column and a gain (amplification factor) of the amplifier unit can be switched in accordance with the color has been mentioned. If the gain differs in dependence on the color, noises due to a color selecting switch such as charge injection, clock feed through, or the like are generated, and a difference occurs between levels of the noise contained in the color signals. Thus, when a dark signal is read out, a step shaped signal level difference occurs between the color signals and appears as a stairway-shaped waveform when seen for the whole one horizontal scanning period. Such a distortion of the waveform becomes a factor which causes DSNU (Dark-Signal-Non-Uniformity) to deteriorate.
The invention is made in consideration of the foregoing problems and it is an aspect of the invention to provide a photoelectric conversion apparatus in which the DSNU is small.

Photoelectric conversion apparatus that amplifies reference voltages corresponding to pixel signals of different colors at different gains


Perpendicular magnetic recording media and methods of fabricating perpendicular magnetic recording media are described. The perpendicular magnetic recording medium of one embodiment includes a soft magnetic underlayer (SUL), an interlayer, and a perpendicular magnetic recording layer. The interlayer comprises a layer formed from a first material (e.g., NiWCr) having a face-centered-cubic (FCC) structure, a layer formed from a second material (e.g., Cr) having a body-centered-cubic (BCC) structure, and a layer formed from a third material (e.g., Ru) having a hexagonal-close-packed (HCP) structure.

1. Field of the Invention
The invention is related to the field of magnetic disk drive systems and, in particular, to a perpendicular magnetic recording medium having an interlayer formed from multiple layers. More particularly, the interlayer is formed from a layer of FCC material (e.g., NiWCr), a layer of BCC material (e.g., Cr), and a layer of HCP material (e.g., Ru).
2. Statement of the Problem
One type of recording medium presently used in magnetic recording/reproducing apparatuses is a longitudinal magnetic recording medium. A longitudinal magnetic recording medium includes a magnetic recording layer having an easy axis of magnetization parallel to the substrate. The easy axis of magnetization is the crystalline axis that is aligned along the lowest energy direction for the magnetic moment. Another type of recording medium is a perpendicular magnetic recording medium. A perpendicular magnetic recording medium includes a magnetic recording layer having an easy axis of magnetization oriented substantially perpendicular to the substrate. Hexagonal-close-packed (HCP) Co-alloys are typically used as the magnetic recording layer for both longitudinal and perpendicular recording. The easy axis of magnetization for these materials lies along the c-axis or <0001> direction.
The perpendicular magnetic recording medium is generally formed with the following layers on a substrate, a soft magnetic underlayer (SUL), an interlayer, a perpendicular magnetic recording layer, and a protective layer for protecting the surface of the perpendicular magnetic recording layer. The soft magnetic underlayer (SUL) serves to concentrate a magnetic flux emitted from a main pole of a write head and to serve as a flux return path back to a return pole of the write head during recording on the magnetic recording layer. The interlayer serves to control the size of magnetic crystal grains and the orientation of the magnetic crystal grains in the magnetic recording layer. The interlayer also serves to magnetically de-couple the SUL and the magnetic recording layer.
The interlayer may be formed from a single layer of material, such as a layer of Ru that has an HCP structure. The interlayer may alternatively be formed from multiple layers. For example, a common interlayer comprises a layer of Ru formed on a seed layer, such as Ta, NiFe, NiW, etc. The seed layer is commonly formed from a face-centered-cubic (FCC) material with the layer of Ru (having the HCP structure) formed on the FCC material. One particular interlayer comprises a seed layer of NiW or another Ni-based alloy, a first layer of Ru deposited at a lower pressure, and a second layer of Ru deposited at a higher pressure.
One problem with many present interlayers for perpendicular magnetic recording media is that they include significant amounts of Ru, which is an HCP material. The thickness of Ru in a common interlayer can reach 200 Å or more. As the cost of Ru and other HCP materials increases, the cost of fabricating perpendicular magnetic recording media unfortunately also increases.

Perpendicular magnetic recording medium having a multi-layer interlayer that includes BCC material

Hitachi Global Storage Techologies Netherlands, B.V.


Disclosed is an inexpensive, bright, compact, lightweight, high-definition projection-type display device that has a comparatively simple structure but satisfies demands for oblique projection, uniform illumination, a deep focal depth, and magnified projection over a short distance. The display device comprises a light source (1a); an illumination portion (1) consisting of a group of collection angle control components, which comprises at least one optical surface (1c) for receiving a principal light ray generated from the imaginary center of the light source (1a) and controlling the solid collection angle thereof, and a group of luminous flux control components, which comprises at least two optical surfaces which are an optical surface (1d) mainly having a spatial distribution control function over the principal light ray in a virtual plane provided perpendicular to the direction of propagation of the principal light ray emitted from the group of luminous flux! control components and an optical surface (1e) for receiving a principal light ray from the surface and mainly having a function of controlling the direction thereof; an image creation portion (2) for creating an original image by selectively reflecting or transmitting luminous flux from the illumination portion (1) and for ensuring that the cone angle of the luminous flux contributing to the image creation does not greatly change before and after; and an imaging portion (3) for collecting the luminous flux emitted from the image creation portion and creating a secondary image on a screen.

1. Technical Field
The present invention relates to a projection-type display device and, in particular, to a projection-type display device suitable for a passive image creation device, exemplified by liquid crystals and/or by a digital micromirror device (DMD) that creates an image by moving a large number of small mirrors independently.
2. Background Art
The recent implementation of the promotion of the high-definition television has led to an increasing demand for large-screen display devices that can be used in ordinary homes. Although there has been progress in increasing the size of CRT devices, which have become standard as conventional display devices, to answer this demand, it is said that structural problems will limit the size thereof to 40 inches. As alternatives, it has become possible to produce plasma or liquid crystal display devices that are thin and have large screens, but these involve problems concerning reliability, lifetime, and particularly cost, so there is no basic solution for a large screen exceeding 60 inches.
Projection-type display devices, which project an original image produced by a small CRT or liquid crystal display device from a front plane or rear plane onto a screen in front of a viewer, have gradually appeared on the market as another method of implementing a large screen. In particular, improvements in compactness, resolution, and transmittance ratio in apparatuses that utilize liquid crystal display devices have astonished consumers and continue to act as a driving force in market diffusion. DMD apparatuses configured of tiny mirrors are also becoming practicable. These differ from CRTs in that they do not generate light in themselves, but are passive image creation devices that require separate illumination portions.
There are a number of technical problems that will have to be conquered to ensure an even wider market presence for a projection-type display device using such a passive image creation device. Representative problems concern: "brightness and uniformity on screen," "space efficiency," "cost," "weight," and "size."
The description below explains in steps the prior-art techniques used to solve the above problems. First of all, the basic configuration of a prior-art projection-type display device is shown in FIG. 36, to illustrate the technical problems concerning "brightness and uniformity on screen." This device is configured of an illumination portion 1 formed of a light source 1a and a parabolic mirror 1c for converting a principal light ray generated from the imaginary center thereof into a parallel beam; an image creation portion 2 formed of an image creation device 2a that selectively transmits luminous flux from the illumination portion 1 and a field lens 2b that controls the direction of the principal light ray; and an imaging portion 3 for projecting the original image created by the image creation portion 2 onto a screen 4. Reference number 3c of the imaging portion 3 denotes an aperture stop for controlling the brightness on screen and 3a, 3b, and 3d denote lenses.
With this optical system, the luminous flux reaching the screen 4 is reduced as the aperture stop 3c is stopped down and thus the imaging portion 3 reduces the cone angle .phi. from the image creation portion 2, so that the efficiency of utilizing luminous flux generated from the light source 1a is radically reduced. This is particularly dramatic when the light source 1a is large in comparison with the image creation portion 2.
Next, assume that the light source 1a is changed in a state in which the aperture stop 3c has been stopped down, in FIG. 36. This time, the efficiency of utilizing the luminous flux rapidly rises as the size of the light-generating portion of the light source 1a is gradually reduced. However, if it is assumed that the angle with respect to the optical axis, of the principal light ray generated from the imaginary center of the light source 1a, which is placed in the vicinity of the focus of the parabolic mirror 1c, is .omega., it becomes conspicuous that the brightness at the periphery of the image creation portion 2 drops, which is an inherent characteristic of a parabolic surface, in proportion to: ##EQU1## as to the angle .omega. increases (that is, with increasing distance from the optical axis). Therefore, when the size of the light-generating portion of the light source 1a is gradually reduced, the cone angle .theta. of luminous flux illuminating the image creation portion 2 can be reduced, and it becomes possible to increase the luminous flux until it is within the range of the cone angle .phi. of the imaging portion 3. On the other hand, this means that it is no longer possible to control the distribution of the cone angle .theta. of the luminous flux and the illuminance distribution in the image creation portion 2.
One means of solving this problem is to use an optical integrator (hereinafter abbreviated to "integrator") as can be seen in Japanese Patent Application Laid-Open No. 3-111806. This method was proposed with the aim of improving the illumination ratio of a conventional projector and eliminating irregularities in the degree of illumination and color of the image, as can be seen in U.S. Pat. No. 2,991,691, for example. The basic configuration thereof is shown in FIG. 37. Luminous flux from a light source 1a is guided by a reflecting mirror 1c into two lens arrays 1d and 1e that configure an integrator, then illuminates a film that configures an image creation portion 2. The luminous flux that passes through this film creates an original image and is projected by a lens of a imaging portion 3 onto a screen 4.
This integrator has two basic functions. In other words, these are an improvement in the efficiency of the luminous flux and an improvement in the uniformity of the brightness. First of all, an improvement in the efficiency of the luminous flux is achieved by a shape-modification function that modifies the circular luminous flux, which has been shaped by the initial reflecting mirror 1c, into the rectangular shape of the film. In an integrator of the most basic two-component configuration, the shape of each individual lens formed in the surface of an integrator on the light-source side, such as that of a lens 1da, is formed to approximate to the shape of the film to achieve this effect. This lens 1da can be considered to be a secondary light source, and a change of shape from a circle to a rectangle is caused by a lens corresponding to the lens 1da in an integrator 1e on the image creation portion 2 side, in other words, by a lens 1ea, to form an image on the image creation portion 2. The lens 1da also functions to create an image of the light source reflected by the reflecting mirror 1c onto the lens 1ea, and thus improve the coupling efficiency of the luminous flux between the lenses 1d and 1e.
The other action concerns uniformity of the brightness, which is achieved by sequentially superimposing secondary images of the light source on the image creation portion 2 by a large number of lens pairs, such as the lenses 1da and 1ea, in accordance with the same principle as that described above. In the above manner, the integrator is a superlative method for simultaneously achieving increased efficiency and uniformity, while having a simple configuration.
However, this integrator is not an universal solution and efficiency could be reduced by conditions imposed by the components configuring the projector. For example, Japanese Patent Application Laid-Open No. 3-111806 presented a number of proposals, based on considerations of the relationship between the size and efficiency of the light source. The basic concepts thereof are shown in FIGS. 38 and 39. There is fundamentally no great difference between FIG. 38 and the previously cited FIG. 37, but points that should be noted are the direction of the electrodes of an electric discharge lamp light source 1a, which is positioned perpendicular to the plane of the paper, and the use of an auxiliary imaging device 1b configured of a spherical mirror. This configuration is not particularly novel, being used in the prior art for overhead projectors and the like, but the combination thereof with an integrator deserves attention. A further step forward is illustrated in FIG. 39, where a portion configured of lenses 1c and 1d and reflecting mirrors 1e and 1f and a double condenser lens system configured of lenses 1c' and 1d' and reflecting mirrors 1e' and 1f' are used to collect the luminous flux from the light source. As a result, the cone angle of the luminous flux incident on an integrator 1g can be reduced and thus the efficiency of this luminous flux can be improved.
To ensure this improvement in efficiency, it is also important to keep the cone angle of the luminous flux at the lens 1d on the light-source side as constant as possible, in addition to the above described relationship between the size of the light source and the collection angle. Otherwise coupling losses will occur in the luminous flux between the lens 1d and the lens 1e. Japanese Patent Application Laid-Open No. 3-111806 provides absolutely no solution to this problem. It simply stops at making the size of each lens in the optical element 1e on the image creation portion side greater than the size of the light source formed thereon, when a conic surface is used for the lens 1c.
Japanese Patent Application Laid-Open No. 7-174974 discloses an example of the use of a reflecting mirror and aspheric lens between the light source and integrator, as means of solving the above described problem inherent to Japanese Patent Application Laid-Open No. 3-111806. A sectional view thereof is shown in FIG. 40. Luminous flux emitted from a light source 1a is guided onto an optical element 1e via a reflecting mirror 1c and aspheric lens 1d in such a manner that the cone angle distribution thereon is uniform. This was proposed to eliminate the coupling losses of luminous flux in Japanese Patent Application Laid-Open No. 3-111806. This example is configured with an awareness of the cone angle and direction control of the luminous flux. However, since it lacks any consideration of the relationships among the cone angle of luminous flux at the optical element 1e, the size of the light source 1a, and the size of the image creation portion 2, and it does not concern the collection angle from the light source as in Japanese Patent Application Laid-Open No. 3-111806, overall structural conditions ensure that the method disclosed in Japanese Patent Application Laid-Open No. 7-174974 cannot be used to construct the surface. This becomes especially obvious as the cone angle of the luminous flux at the optical element 1e becomes smaller, or the size of the light source 1a becomes relatively large in comparison with the size of the image creation portion 2.
To reduce the cost and increase the yield of image creation devices such as liquid crystal devices, it is most effective to design a smaller device and increase the number of elements that can be produced from a single wafer. However, this would be the cause of a huge decrease in the efficiency of luminous flux. For that reason, there is currently a great deal of work being done on increasing the illumination efficiency, starting with the above described integrators, but this is linked to an increase in the cone angle of the luminous flux in the image creation portion. Therefore, a lens with a small F number (a large cone angle) must be used in the imaging portion. It is not uncommon recently for a lens of F2 class (a cone angle of 29 degrees) to be used, which increases the cost of the imaging portion.
In contrast to this use of a lens with a small F number, some image creation devices necessitate the use of an imaging portion with a large F number. Intense interest has recently been focussed on a display device using a polymer dispersed liquid crystal, as a means for improving the brightness of a liquid crystal display device. A major feature of this display device is the use of the scattering characteristic of a liquid crystal sealed into a small region to make the image visible. This differs from the usual method in which the polarization characteristic is utilized so that the image is made visible with the aid of a polarizer, and has the advantage that the lack of this polarizer can be expected to improve the brightness by an equivalent amount. This concept is illustrated in FIGS. 41 and 42. Note that, although these figures show a transmissive system, the principles are exactly the same for a reflective system. FIG. 41 shows a transmission mode and FIG. 42 shows a scattering mode. In these figures, when luminous flux f is incident on a polymer dispersed liquid crystal, in the transmission mode it is transmitted therethrough unchanged, but in the scattering mode it forms scattered light with a substantially circular diffusion pattern. By switching between these two modes an image is created utilizing changes in light quantity within a region of a specific solid angle.
From the above principle, how the scattered light that reaches the screen in scattering mode is reduced is a decisive factor in improving the contrast. For that reason, an optical system called a Schlieren optical system is employed in the imaging portion 3, but this has a disadvantage in that the F number is large. In other words, this means that a high contrast is obtained by reducing the cone angle .phi. of the collected luminous flux, thereby reducing the scattered light that reaches the screen. Therefore, although this device has an advantage in being brighter because there is no need for a polarizer, this is cancelled by the stopping down achieved by reducing the cone angle .phi. of the imaging portion 3, so there is a danger that in fact the image will end up even darker.
If, as an experiment, the F number of the imaging lens that is usually used is made to be approximately 4 and the most suitable F number for ensuring contrast with a polymer dispersion device is 11, the brightness is reduced to 1/8. The effect of removing the polarizer is at most approximately 1/3, so it is clear that the brightness could be reduced to one half or less, as feared.
An optical system using such a polymer dispersed liquid crystal, as disclosed on page 113 of Japan Display '92, is shown schematically in FIG. 43. In this example, a metal halide lamp with a gap of 5 mm is used as a light source 1a and light that has been focussed once by an elliptical mirror 1c is converted into a parallel beam by a collimeter lens 1d. A 3.4-inch polymer dispersed liquid crystal is used as an image creation device 2a, and, after the light has passed through a field lens 2b, it is projected onto a screen 4 by a lens system 3 with an F number of 9.5 (a cone angle of 6 degrees). If a light source 1a of 150 W is used, the luminous flux on the screen is 400 lm.
The illumination portion of FIG. 43 is configured of the single elliptical mirror 1c alone, as described above, but, if the amount of light output per watt of the light source is 2.6 lm/W, a comparatively high efficiency will be exhibited. This is because a liquid crystal panel 2a that configures the image creation portion 2 is comparatively large at 3.4 inches and the light source 1a is relatively small, so that the cone angle .theta. of luminous flux on the panel can be reduced. However, if it is decided to reduce the size of the panel to reduce costs, it is no longer possible to maintain this high efficiency by the elliptical mirror alone. This is because there are technical limits to reducing the size of the light source 1a together with the panel size, which result in an increase in the cone angle .theta. of luminous flux incident on the panel 2a, bringing about the previously described problem concerning the F number.
The description now turns to a consideration of the prior-art techniques for solving the second of the technical problems relating to the popularization of projection-type display devices: "space efficiency." The best kind of projection-type display device is of a front projection type that projects an image onto the screen from the same side as that of the viewers. Unfortunately, this type of display device has a large disadvantage in that it takes up part of the space that ought to be occupied by the viewers. Several methods have been used to counter this problem, such as mounting the projector on the ceiling, but the overall cost of extras such as reinforcement of the ceiling is one of the reasons why the front projection type is not popular.
The same type of projector can also be used as a rear projection type, as shown in FIG. 44. In this case, luminous flux from a projector 7a is bent by plane mirrors 7b and 7c, then is projected onto a screen 4. With this rear projection type, it is necessary to shorten the focal distance of the imaging portion in order to reduce the depth of the display device itself. This is equivalent to employing a wide-angle lens in the imaging portion. In the same way as with a pickup element, it might be considered to shorten the focal length of the camera lens that is used, together with reducing the size of the light-receiving portions. However, with a passive image creation device, there is the usual problem with the size of the light source so that there is a limit on the relationship with the efficiency of the luminous flux. Thus it is currently difficult to make the device even more compact.
An optical projector has been proposed in Japanese Patent Publication No. 6-1295. The basic configuration thereof is shown in FIG. 45. This optical projector is provided with a light source 1a having a small light spot, such as a xenon lamp, and reflecting mirrors 1c and 1d providing control over the luminous flux to reproduce a secondary point light source 1a'. In this case, 1b denotes an auxiliary imaging device that operates in the same way as the auxiliary imaging device 1b of FIG. 38 and 1e denotes a flat reflecting mirror that simply bends the luminous flux back. By placing an image creation portion 2 between the thus created secondary point light source 1a' and a screen 4, which is not shown in the figure, an image can be projected onto the screen by the shadowgraph principle. The main purpose of the luminous-flux controlling reflecting mirrors 1c and 1d is to create the secondary point light source 1a' for creating an image of uniform brightness, from consideration of the luminance distribution and luminance intensity distribution of the lamp and differences in distance between each part of the image creation portion 2 and the secondary image on the screen. In other words, their main purpose is to control the illuminance distribution and direction of luminous flux generated from the light source.
Among the main features of this optical projector are four features that make this projector extremely useful: 1) it is possible to project an expanded image from a short distance, 2) oblique projection is possible, 3) uniform brightness can be guaranteed over the screen, and 4) the deep focal depth enables focusing at any place (focus-free). If it is possible to use such a projector, the projection can be from a position at which the viewers are not inconvenienced and the space efficiency problem can be solved at a stroke.
The measures used to solve each of the above technical problems tend to increase the cost of the entire apparatus, which has an effect on the third technical problem relating to the projection-type display device. For example, a microlens array could be employed in the liquid crystal display device that is one of the main components of a passive display device, to improve the transmittance ratio. Similarly, further increases in cost are caused by employing a special illumination system comprising components such as a polarizing prism and an optical integrator to improve the efficiency, and increasing the number and size of lenses in the lens assembly and also employing a dichroic prism to reduce the F number of the imaging lens and reduce the focal distance. Therefore, even if the image creation device is made more compact to reduce costs, that will be offset by the measures used to improve the illumination efficiency.
An example of the use of a reflective optical system in the imaging portion 3 is shown in FIG. 46, as a final example of a prior-art projection-type display device. In this example, a CRT is used as the image creation portion 2. A CRT is a representative example of an active image creation portion that generates its own luminous flux. The imaging portion 3 consists of a reflecting mirror 3a and a correction plate 3b, to configure a system called a Schmidt system. This imaging portion 3 is employed to increase the efficiency of this luminous flux and make the projected image brighter, because the luminous flux from the image creation portion 2 is divergent light, but the resolution is not very good. The advantages and disadvantages of this configuration have already been made clear in the general literature on the Schmidt camera, so they are omitted herefrom. Even now, it is for the purpose of improving the efficiency of luminous flux having a wide dispersion angle that a lens system with an F number in the 1.0 class is used in a projector utilizing a CRT.
The effective obverse of the large aperture of the reflective system utilized in the imaging portion 3 of FIG. 46 is a difficulty in obtaining a large angle of view. That is why it is mainly used in applications such as large-aperture telescopes. In recent projection-type display devices, as touched upon in the example of the rear projection type, there is an increasing tendency for the imaging portion to have a large angle of view, and thus it is difficult to adopt such a configuration. However, this suggests that it is possible to simplify the optical system by using a reflective optical system.
As described above, the various technical problems of "brightness and uniformity on screen," "space efficiency, " "cost," "weight," and "size" must be solved in a comprehensive manner, to enable the projection-type display device to achieve wide market acceptance as a large-scale display device. As should be clear from the above discussion of the prior-art techniques, not only is it inevitably necessary to improve the individual technologies, we should go further and consider that we are approaching a time at which we should basically rethink the configuration and purpose themselves, in order to solve such intricate problems.
In this context, the optical projector of the previously mentioned Japanese Patent Publication No. 6-1295 has four extremely good features. However, implementation of this projector involves a number of problems. These can be summarized as two main problems. One is the problem of resolution; the other is a problem concerning mass production. First of all, concerning the problem of resolution, theory states that the effects of half-shadows and diffraction are obvious in the creation of a secondary image by the shadowgraph principle from luminous flux from a light source that is close to being a point source. Thus it is not possible to respond to demands for a resolution that exceeds a certain level. This problem is caused by the lack of an imaging portion in the above optical projector. Two particular problems concerning mass production that can be raised are: "scratches and unevenness in the reflective surfaces used affect the final image" and "shaping accuracy of the reflective surfaces is strict." Conquering these will require an extremely high level of machining accuracy, which is the biggest problem from the mass-production viewpoint. Both of these are also common reasons for making the light-generating portion of the light source extremely small. In contrast thereto, there is also a conflicting problem in that it is difficult to obtain a "light source having a small, bright light spot," to improve the brightness and resolution.
The present invention was developed with the objectives of solving each of these technical problems and satisfying all of the conditions that ought to be provided by a projector, while keeping the advantages of the optical projector of Japanese Patent Publication No. 6-1295. In other words, the objective of this invention is to simultaneously achieve both the technical and manufacturing conditions of:
(1) Implementing the four major features of a magnified projection over a short distance, oblique projection, a uniform illumination, and a deep focal depth, with a bright, high-resolution image. PA1 (2) Providing a compact, light-weight, and inexpensive projection-type display device.
To summarize the technical fields that the present inventor has returned to and fundamentally reconsidered in this case, I have clarified the relationships among the characteristics of the light source, the cone angle of the luminous flux, and control over the luminous intensity distribution, illuminance distribution, and directionality thereof as well as the dimensions of the image creation portion, relating to the implementation of the features listed in (1) above, and have determined a basic way of considering how to construct the illumination portion in practice. These make it possible to implement optimization of the disposition and surface shape of the various optical elements configuring the illumination portion in accordance with the dimensions, shape, luminance distribution, and luminance intensity distribution of the light-generating portion of the light source, and the dimensions and characteristics of the image creation portion.
A reflective optical means is used in the imaging portion, and, as a further step, a configuration has been enabled in which the imaging portion has only a few reflecting mirrors, to implement the features listed in (2) above. In a prior-art projector, it is difficult even just to concentrate on brightness by configuring the imaging portion having such characteristics with only a few mirrors. As described above, the object of the present invention is to implement an ideal projector that satisfies the conditions listed in (1) and (2) above, by implementing a highly efficient, highly sophisticated illumination portion by suitable utilization based on a comprehensive overview of the various luminous flux control techniques, and applying this illumination portion to satisfying the conditions imposed on the imaging portion.


A universal frequency translation module (UFT) frequency translates an electromagnetic (EM) input signal by sampling the EM input signal according to a periodic control signal (also called an aliasing signal). By controlling the relative sampling time, the UFT module implements a relative phase shift during frequency translation. In other words, a relative phase shift can be introduced in the output signal by sampling the input signal at one point in time relative to another point in time. As such, the UFT module can be configured as an integrated frequency translator and phase-shifter. This includes the UFT module as an integrated down-converter and phase shifter, and the UFT module as an integrated up-converter and phase shifter. Applications of universal frequency translation and phase shifting include phased array antennas that utilize integrated frequency translation and phase shifting technology to steer the one or more main beams of the phased array antenna.

1. Field of the Invention
The present invention is generally related to frequency translation, phase-shifting, and applications of the same, including but not limited to antenna applications.
2. Related Art
Various communication components exist for performing frequency down-conversion, frequency up-conversion, phase shifting and filtering. Also, schemes exist for signal reception in the face of potential jamming signals.

Phased array antenna applications of universal frequency translation


An anti-theft device is constituted by an elongated rod of a width less than the gap between a window glass pane and a facing inner edge of a window sill for an automobile door interior panel. A shield plate is fixed to and extends radially outward to one side of the rod at a distal end, and a wedge is fixed to and extends alongside the rod adjacent the proximate end, with the wedge having a thickness greater than the width of the gap and tapering over its length to a tapered leading edge facing the trailing edge of the shield plate. By inserting the shield plate into the interior of the door within the gap and twisting the rod about the axis, the wedge is forced into frictional locking position between the inside of the window glass pane and the window sill, with the shield plate covering the door mechanism actuating lever.

Motor vehicle anti-theft devices are known in the art. U.S. Pat. No. 4,113,294 is directed to an anti-theft clip for securing a lock cylinder to a car door consisting of panels attached to resilient legs which straddle and hold the lock cylinder, however, the device does not protect against the downward insertion of a stiff rod to reach the lock levers.
U.S. Pat. No. 4,628,300 is directed specifically to a motor vehicle anti-theft device designed to prevent access to the levers which control the operating of the door lock within a vehicle door. An L-shaped metal plate including a horizontal cover strip of rigid material of predetermined length and width is employed to substantially cover the space between the vehicle window glass pane and the outside panel of a vehicle door with a vertically downwardly projecting right angle support strip which is attached internally within the door cavity to the sash of the automobile window to prevent the insertion of a tool to release the lock actuating levers within the vehicle door.
The anti-theft device of the U.S. Pat. No. 4,628,300 requires access to the interior cavity between the exterior door panel and the interior door panel and a permanent modification of the vehicle door assembly.
It is therefore an object of the present invention to provide an improved, simple, unitary anti-theft device for blocking access to the insertion of a thin metal tool between the window pane and the exterior panel of a vehicle door to move one or more of the actuating lever arms attached to the door latch release mechanism which may be manually inserted between the interior door panel and the window glass pane, which device may be frictionally locked in place and which carries a shield plate of predetermined size which is effectively positioned adjacent to the door latch release mechanism thereby preventing contact by an inserted metal tool attempting to mechanically release the door latch mechanism.

Insertable motor vehicle anti-theft device


A suspension having a magnetic head assembly 1 mounted thereon is provided, wherein the magnetic head assembly comprises: a write head 1-2; a read head 1-1; and a resistive heating element 1-3 for controlling the flying heights of the magnetic heads, wherein the wires HTx and GTx for the resistive heating element is disposed such that they sandwich the wires RxX and RxY for the read head. The wires for the resistive heating element may be disposed between the wires for the write head and the wires for the read head. Furthermore, the waveform of the current or voltage to the resistive heating element has a time constant of 1 μsec or more, the resistive heating element having wires disposed near the wires of the read head.

The invention relates to controlling the flying height of a magnetic recording disk drive; and, more specifically, the invention relates to preventing a crosstalk against the read head.
A conventional magnetic recording disk drive (hereinafter referred to as HDD) comprises a head/disk assembly that is a mechanical system, and a package substrate (PCB) made of circuits. FIG. 13 shows the configuration of a head/disk assembly (HDA) 100. The HDA 100 comprises components such as: a magnetic recording disk 2 installed in a chassis (base) 8 through a spindle 5; a magnetic head assembly 1 mounted on the tip of a suspension 3 connected with an actuator 4 driven by a voice coil motor (VCM) 7; a flexible printed cable (FPC) 6-3 having mounted thereon a read/write IC (R/W IC) 11 which electrically drives the magnetic head assembly 1. The actuator 4 moves the magnetic head assembly 1 so as to position it at an arbitrary location while the magnetic disk 2 is being rotated at a constant speed before the write/read operation begins.
FIG. 14 shows how the magnetic head assembly 1 is suspended above the magnetic recording disk 2 in a read/write operation. Due to increasing recording density of a magnetic recording disk drive, reduced flying hht of the magnetic head is required. With a reduced flying height, however, the write head element (WRT) 1-2 or the read head element (RD) 1-1 is likely to collide with a small bump 51 with a height of a few nanometers. These bumps are formed due to, for example, the surface roughness of the magnetic recording disk 2.
The flying height of the magnetic head assembly above the magnetic recording disk 2 is set to a small value, for example no more than 20 nm, in recent years. Assume that the small bump 51 has collided with the read head element (RD) 1-1. In such a case, if the RD 1-1 is a magnetoresistive head (hereinafter referred to as an MR head), the element produces heat and thereby an abnormal signal is generated by a thermal asperity (hereinafter referred to as TA) event. Such an incident results in a read abnormality. Further, when a high-frequency write current of a few hundred megahertz flows through the write head element (WRT) 1-2, the element produces heat and thereby the rear end of the magnetic head assembly projects toward the disk surface, as indicated by the broken lines in the figure. The higher the frequency of the high-frequency current, the larger the projection amount, reaching a few nanometers or more, due to the heat produced by the eddy current. With a reduced head flying height, a head element of the magnetic head assembly might be damaged if it protrudes.
FIG. 15 shows wiring (FPC) 6-1 on the suspension 3 for a magnetic head assembly implemented by a prior art that does not use a resistive heating element HEAT 1-3. A crosstalk current flows through wires RxX and RxY on the RD side due to the high-frequency current flowing through wires WxX and WxY on the WRT side and the flyback voltage in the write operation. The sense current supplied to the read head 1-1 is generally between 2 mA and 3 mA, and if the WRT side and the RD side are in close proximity, the crosstalk current might be as large or larger than the sense current. Since the read sensitivity increases with increasing sense current, the sense current is preferably set as large as possible within the allowable range. Further, at the same time, long life duration is required.
However, in case of a crosstalk, the value of the sense current must be reduced. Therefore, the wires on the WRT side are disposed away from the wires on the RD side to reduce the crosstalk current, and thereby increase the allowable value of the sense current. Also, an alternating current against the MR element of the read head, which is caused by the crosstalk current from the WRT side to the RD side leads to a reduction in the life duration of the MR element itself.
One technique used to solve the above problems is to install the resistive heating element HEAT 1-3 near a head element whose flying height has been increased beforehand, as shown in FIG. 14. With this arrangement, the protruding action of the head element due to heat from the resistive heating element HEAT 1-3 is rather utilized in order to control the flying height of the head element (see Japanese published application JPA 5-020635). There are various ways in which this resistive heating element is used. Generally, however, a current is passed through the resistive heating element in the read operation so as to reduce the flying height of the head element by using the heat produced by the resistive heating element. In the write operation, on the other hand, the current to the resistive heating element is basically cut off since due to the high-frequency write current flowing in the write operation, heat is already being produced, reducing the flying height. However, an appropriate amount of current may be applied in a low-temperature environment such as when the equipment is started. Alternatively, a low current may be applied all the time while adjusting its magnitude in order to provide some narrow flying height.
Another proposed prior art technique is to implement a magnetic head assembly which includes a heating magnetic head in addition to the write magnetic head and the read magnetic head (see Japanese published application JPA 11-096608). The technique disclosed in Japanese published application JPA 11-096608 increases the temperature of a recording portion of the recording medium to a value corresponding to the write or read temperature in the write or read operation by use of the heating magnetic head, making it possible to read from or write to narrowed tracks.
However, in Japanese published application JPA 5-020635, neither the detailed means nor the circuit configuration for controlling the amount of the generated heat is disclosed.
Furthermore, if new wiring is provided on the FPC 6-1 to supply power to the HEAT 1-3 in the prior art technique shown in FIG. 15, it may be necessary to reduce the distance between the wires WxX/WxY on the WRT side and the wires RxX/RxY on the RD side. This might result in an increase in the crosstalk current. Increased crosstalk current leads to reduction of the sense current to ensure adequate head life duration, which is not preferable. Further, the power supplied to the resistive heating element HEAT 1-3 is a maximum of a few ten milliwatts. Assuming that the resistance of the HEAT 1-3 is between some ten ohms through some hundred ohms, the current and the voltage amount to some ten milliamperes and a few volts, respectively. Therefore, if the current supplied to the HEAT 1-3 is switched on/off while data on a magnetic recording disk or a servo signal is being read, a large crosstalk current flows through the wires on the RD side, which can cause an abnormality in the read operation.
On the other hand, the heating magnetic head described in Japanese published application JPA 11-096608 is provided to increase the temperature of the recording media; it is not intended to control the flying height of the magnetic head. Furthermore, no consideration is given to the adverse effect of a crosstalk current against the read magnetic head, which is caused by switching the current on/off in the heating magnetic head, or by the high-frequency write current of the write magnetic head.

Suspension having magnetic head assembly mounted thereon and magnetic recording disk drive using the suspension

Hitachi Global Storage Technologies Japan, Ltd.


The method of the present invention is useful in detecting the lack of majority cluster nodes within a cluster, and reorganizes the cluster membership to allow for running with less than a majority of nodes connected. As nodes become alive, they are added to the cluster until the original majority is reached, which then allows for the cluster to return to normal operation. Thus, the method of the present invention allows for the revival and reconstitution of a majority node set of clusters.

1. Field of the Invention
The present invention generally relates to utilizing underlying cluster systems to provide the functionality of reviving and reconstituting majority node set clusters. The methods of the present invention provide ways to have the cluster continue even if the number of nodes falls below what is designated as a majority. It then returns the cluster back to normal operation once the number of nodes available increases to the correct level, which has been designated in advance.
2. Description of Related Art
The present invention generally relates to utilizing underlying cluster systems to provide the functionality of reviving and reconstituting majority node set clusters. The methods of the present invention provide ways to have the cluster continue even if the number of nodes falls below what is designated as a majority. It then returns the cluster back to normal operation once the number of nodes available increases to the correct level, which has been designated in advance.
Today, in a traditional Microsoft Cluster Service (MSCS) cluster, a cluster can continue as long as one of the nodes owns the quorum disk. The Microsoft Cluster Service (MSCS) is software for the creation and management of a cluster. A cluster is a group of servers and other resources, in a computer system, that act like a single system and enable high availability and, in some cases, load balancing and parallel processing. Any nodes that can communicate (via heartbeats) with the quorum owner are part of the cluster and can host resources. Heartbeats in a cluster service are messages sent regularly by the Cluster Service on one node to the Cluster Service on another node across a private network connection. Any other nodes that are configured to be in the cluster, but cannot communicate with the quorum owner are said to have lost quorum and thus any resources that they are hosting, are terminated. A node is a computer system that is a member of a cluster. A traditional Microsoft Cluster Service (MSCS) cluster can continue as long as that node owns the quorum disk. A cluster running with a majority node set quorum resource will only start up or continue running if a majority of the nodes configured for the cluster are up and running and can all communicate with each other. The majority node set is a single quorum resource from an MSCS perspective. This majority node set resource takes care to ensure that the cluster configuration data stored on the majority node set is kept consistent across the different disks. The failure semantics of the cluster behaves on node failures and partitioned or split-brain scenarios, thus, care must be taken when deciding whether to choose a traditional MSCS cluster using a physical disk resource or cluster that uses a majority node set as a quorum resource.
There is a single quorum of nodes resource in the cluster and it is brought online on one node at any one time, just like any other cluster resource. A quorum is a disk resource used to store information about the current cluster configuration. The majority node set resource is responsible for ensuring that the quorum data is kept consistent on all disks around the cluster. When a cluster is setup to have a majority node set, a file share is created on that node. As described above, each node in a majority node set cluster has a file share that exports the quorum directory, so that, regardless of where the majority node set resource is hosted, it can write to all the members of the majority node set.
It is, therefore, necessary to devise a method to revive and reconstitute majority node set clusters after a node failure. Therefore, this invention provides a mechanism to bring the cluster back online, while looking at the rest of the cluster nodes, and bring them back in.
One related art method to which the method of the present invention generally relates is described in U.S. Pat. No. 6,115,830 entitled "Failure Recovery For Process Relationships In A Single System Image Environment". This prior art method is a system for recovery of process relationships following node failure within a computer cluster. For relationship recovery, each node maintains set of care relationships. Each relationship is of the form the carer cares about the care target. Care relationships describe process relations such as parent-child or group leader-group member. Care relationships are stored at the origin node of their care targets. Following node failure, a surrogate origin node is selected. The surviving nodes then cooperate to rebuild vproc structures and care relationships for the processes that originated at the failed node at the surrogate origin node. The surviving nodes then determine which of their own care targets were terminated by the node failure. For each of the terminated care targets, notifications are sent to the appropriate carers. This allows surviving processes to correctly recover from severed process relationships.
The present invention differs from the above related cited art in that the prior invention focuses on detecting the lack of a majority of nodes to be within the cluster and reorganizes the cluster membership to allow for running with less than a majority of nodes connected. In the instant invention, however, as nodes become alive, they are added to the cluster until the original majority is reached and then the invention allows the cluster to return to normal operation.
Yet another related art method to which the method of the present invention generally relates is described in U.S. Pat. No. 6,401,120 entitled "Method And System For Consistent Cluster Operational Data In A Server Cluster Using A Quorum Of Replicas". This prior art method is a method and system for increasing the availability of a server cluster while reducing its cost by requiring at a minimum only one node and a quorum replica set of storage devices (replica members) to form and continue operating as a cluster. A plurality of replica members maintain the cluster operational data and are independent from any given node. A cluster may be formed and continue to operate as long as one server node possesses a quorum (majority) of the replica members. This ensures that a new or surviving cluster has at least one replica member that belonged to the immediately prior cluster and is thus correct with respect to the cluster operational data. Update sequence numbers and/or timestamps are used to determine the most updated replica member from among those in the quorum for reconciling the other replica members.
The present invention differs from this related art in that the cited related art deals with storing multiple copies of the quorum on external shared disks. Therefore, a cluster will be operational if at least one node is online and can access a majority of quorum copies. The difference here is that in the instant case, quorum data is stored locally on each nodes' internal drives. The present invention, however, relies on the underlying cluster service to maintain the data. This instant invention affects the cluster only when the number of member nodes falls below a majority. Once that occurs, the new invention allows for bringing the cluster together using the working nodes. The cluster itself will find the most up-to-date data.
Yet another related art method to which the method of the present invention generally relates is described in U.S. Pat. No. 6,163,855 entitled "Method And System For Replicated And Consistent Modifications In A Server Cluster". This prior art method is a method and system for communicating modification information to servers in a server cluster. Local changes, such as modifications to a resource requested at one node, are associated into a single transaction. A master node, such as the node that owns the set of resources corresponding to the modifications in the transaction requests permission from a locker node to replicate the transaction. When permission to replicate the transaction is received from the locker node, the master node replicates the transaction by requesting each node in the cluster, one node at a time, to commit the transaction. Any node that does not commit the transaction is removed from the cluster, ensuring consistency of the cluster. Failure conditions of any node or nodes are also handled in a manner that ensures consistency.
The present invention differs from this related art in that the cited related art only describes a system for ensuring that copies of the quorum on each node are kept up to date. The present invention builds on the cluster system similar to that described above. The present invention allows for the cluster to function even when it has less member nodes than it normally needs to run. The invention allows the cluster to return to normal operation when the number of available nodes returns to the expected level.
Yet another related art method to which the method of the present invention generally relates is described in U.S. Pat. No. 6,336,171 entitled "Resource Protection In A Cluster Environment". This prior art method is a method of protecting volumes of a mass storage device shared by a server cluster and includes the step of transferring from (i) a first file system of a first server of the server cluster to (ii) a first filter driver of the first server, (iii) a write request packet directed to a first volume of the mass storage device. Another step of the method includes determining at the first filter driver whether the first server has ownership of the first volume. Yet another step of the method includes transferring the write request packet from the first filter driver to a lower level driver for the mass storage device only if the determining step determines that the first server has ownership of the first volume. Apparatus for carrying out the method are also disclosed.
The present invention differs from this related art in that the cited related art only describes the methods used to operate a clustered environment. The method of the present invention utilizes an underlying cluster system to also provide this functionality. The method of the present invention also provides methods to have the cluster continue even if the number of nodes falls below a majority. Finally, the present invention also returns the cluster to normal operation once the number of nodes available increases to the correct level.

Method to revive and reconstitute majority node set clusters


An apparatus for testing an integrated circuit in an oven during burn-in. A burn-in board in the oven is electrically connected to a plurality of integrated circuit ("IC") components. A driver/interface board outside the oven is electrically connected to the burn-in board through a plurality of contacts and sends and receives a plurality of signals between the IC components and a test controller. A switch module on the burn-in board comprises a plurality of high-temperature switches for transferring signals between the plurality of IC components and the driver/interface board during burn-in. A plurality of signals entering the switch module from the driver/interface board does not exceed in number the plurality of contacts, and is fewer in number than a plurality of signals exiting the switch module to the plurality of IC components.

Integrated circuits are often tested after manufacture by electrically stressing the devices in an elevated temperature for a period of time to cause failure of marginal devices. This process is referred to as burn-in. Multiple integrated circuit chips are placed on a burn-in board that is similar to a computer add-on card, but usually much larger. The burn-in board is a printed circuit board with receptacles for the integrated circuit chips. The burn-in board also includes printed circuit connections between pins of the integrated circuit chips and connectors of the burn-in board.
FIG. 1 shows a prior integrated circuit testing system 100. Oven 202 encloses multiple burn-in boards, each of which holds multiple integrated circuit ("IC") chips. The burn-in boards (not visible in FIG. 1) inside oven 202 are electrically connected to respective driver/interface boards 211a through 211n, 212a through 212n, and 213a through 213n. Each driver/interface board of driver/interface boards 211a through 211n, 212a through 212n, and 213a through 213n is electrically connected in turn to computer 206. Computer 206 controls the driver/interface boards with software that controls the testing of the integrated circuit chips.
FIG. 2 is a cutaway transparent view of oven 202 showing one row of burn-in boards 208a through 208n secured in one rack 210 within oven 202. For example, seventy-two burn-in boards can be placed in oven 202 at one time through the use of multiple racks at various levels. Other numbers of burn-in boards are possible.
Burn-in boards 208a through 208n have respective male connectors 204a through 204n. Typically, each burn-in board of boards 208a through 208n has seventy-two electrical strip contacts that comprise the male connector. For example, connector 204a has seventy-two contacts, with thirty-six of the contacts on one side of connector 204a and thirty-six of the contacts on the opposite side of connector 204a.
Driver/interface boards 211a through 211n have respective female connectors 205a through 205n. Typically, each driver/interface board of boards 211a through 211n has seventy-two contacts that comprise the female connector. For example, connector 205a has seventy-two contacts, with thirty-six of the contacts on one side of connector 205a and thirty-six of the contacts on the opposite side of connector 205a.
Male connectors 204a through 204n are connected into respective female connectors 205a through 205n and provide electrical pathways between driver/interface boards 211a through 211n and burn-in boards 208a through 208n. Driver/interface boards 211a through 211n are in turn electrically connected to computer 206. Burn-in boards 208a through 208n each include IC chips 302a-n through 312a-n, and those IC chips are accordingly electrically connected to computer 206.
As shown in FIG. 2, multiple integrated circuit chips 302a through 302n are arranged in columns and rows on burn-in board 208a. Each of integrated circuit chips 302a through 302n receives clock, power, and ground signals. Each of integrated circuit chips 302a through 302n is powered during the entire test period. Some of the contacts of connectors 204a and 205a are used for clock, power, and ground signals. This reduces the number of contacts available to carry other signals. For example, typically eight contacts are used on connector 204a to carry clock, power, and ground signals, leaving sixty-four contacts available to carry other signals. The other burn-in boards 208b through 208n have similar configurations. For example, integrated circuit chips 303a through 303n reside on burn-in board 208b, and integrated circuit chips 312a through 312n reside on burn-in board 208n.
For a burn-in board such as burn-in board 208a, the number of IC chips 302a through 302n is limited by the number of contacts of connector 204a and by the number of pins being used on each of the IC chips 302a through 302n under test. Different types of IC chips have different pin-outs.
For instance, an IC chip with sixteen pins and two control signals typically requires fewer signals at any one time than an IC chip with forty-eight pins and four control signals. An IC chip requiring fewer signals at any one time during the burn-in procedure requires the use of fewer contacts of connector 204a at any one time. It follows that burn-in board 208a can accommodate more of those IC chips that require few signals than those IC chips that require many signals. For a memory having a 32-bit data word and 215 (i.e., 32 k) address locations, seventy-two of these IC chips can be accommodated on burn-in board 208a. Similarly, seventy-two of these IC chips can be accommodated on each of burn-in boards 208b through 208n.
Driver/interface board 211a includes driver area 304a and logic area 306a. Driver area 304a contains a driver for each contact within connector 205a on the driver/interface board. Logic area 306a contains logic for receiving and processing signals sent from computer 206 to burn-in board 208a. Driver/interface boards 311b through 311n have similar respective driver areas 304b though 304n and logic areas 306b through 306n.
Typically in prior burn-in test systems a computer program causes computer 206 to send signals to the integrated circuit chips 302a-n through 312a-n on respective burn-in boards 208a through 208n via respective driver/interface boards 211a through 211n. The signals toggle various device pins under elevated temperatures for some test period. For example, pins of the IC chips 302a through 302n are sent alternating logic one and logic zero signals--usually 5 volts alternating with zero volts. After some period, typically as long as twenty-four hours, the burn-in board 208a is removed from the oven. The integrated circuit chips 302a through 302n are then removed from the board 208a by hand and placed on an IC electrical tester (not shown) that resides outside of oven 202. The IC electrical tester is a separate external unit designed specifically for determining the functionality of the integrated circuit chips and operates the IC chips at room temperature. If any of the integrated circuit chips 302a through 302n failed during the burn-in process, the failure is discovered typically during various tests after burn-in, and each failed IC chip is discarded. A similar procedure is used for IC chips 303a-n through 312a-n of respective burn-in boards 208b through 208n.
One disadvantage of the prior burn-in test system 100 is the need for extensive testing of IC chips after burn-in to determine whether they have failed. The external testers used for this testing are very expensive, usually costing millions of dollars, and are also expensive to operate. In addition, each test which must be performed by the external testers after burn-in requires more labor and time. For these reasons, it would be very desirable to perform functional tests on IC chips while they are undergoing burn-in.
Because of limitations of prior burn-in test systems, it is not possible to perform many functional tests on IC chips while they are in the oven. For example, for IC chips that are memory devices with data words of thirty-two bits or more, the typical burn-in board and driver/interface board pin configuration of prior burn-in test systems prevents the testing of the memory devices while they are in the oven 202. Because a limited number of pins 204a connect burn-in board 208a with the driver/interface board 211a, not enough pins 204a are available to carry various control signals and address signals at the same time as thirty-two data signals. This can be explained using, for example, a memory with 32-bit wide data words and a 2.sup.15 (i.e., 32 k) address space. Such a memory is typically referred to as a "32K.times.32" memory. Fifteen address lines are needed to address the 2.sup.15 address space. Assuming that there is an array of 8 rows and 9 columns of memories under test on a burn-in board, seventeen device select lines are required. Five lines are typically required for control and clock, but the number can vary depending on the particular memory under test. Fifteen address lines plus seventeen device select lines plus five control and clock lines results in a total of thirty-seven lines of that are used out of sixty-four available contacts of connector 204a. Thus, only twenty-seven contacts remain unused, which is not enough to carry thirty-two bits of data to be read from a memory device.

Apparatus for testing an integrated circuit in an oven during burn-in