The present invention provides a display device and a dual gate type thin film transistor (TFT) structure for an electronic device. According to an embodiment, the dual gate TFT structure includes a first gate electrode formed on a substrate; a semiconductor layer formed on the first gate electrode; an insulating layer formed on the semiconductor layer, and including first, second and third contact holes therein; drain and source electrodes in contact with the semiconductor layer respectively through the first and second contact holes; a passivation layer formed on the drain electrode and the source electrode, and including a fourth contact hole therein; a planarization layer formed on the passivation layer, and including a fifth contact hole therein; and a second gate electrode formed on the planarization layer, and in electrical contact with the first gate electrode through the third, fourth and fifth contact holes.

1. Technical Field
The present invention relates to a display device, and more particularly, to an array substrate for a display device having a dual-gate structure and preventing an electrical short.
2. Discussion of the Related Art
Recently, as the society has entered an information age, various types of display devices that represent all sorts of electrical signals as visual images have been developed rapidly. For example, a liquid crystal display (LCD) device and an organic light emitting diode (OLED) display device have been widely introduced and used as a substitute for a display device of cathode-ray tube type.
A general LCD device has characteristics of light weight, thinness and low power consumption. A general OLED display device of new flat panel display devices has high brightness and low driving voltage. The OLED display device is a self-emitting type and has excellent characteristics of a view angle, a contrast ratio, a response time and so on.
The LCD device can include array elements on a first substrate and color filters on a second substrate. The array element for the LCD device includes a gate line, a data line, a thin film transistor (TFT) as a switching element and a pixel electrode. The array element for the LCD device may further include a common electrode.
On the other hand, the OLED display device can include array elements on a substrate and an organic light emitting diode connected to each array element. The array element for the OLED display device includes a switching thin film transistor (TFT) (which is connected to a gate line and a data line), a driving TFT (which is connected to the switching TFT), and a power line connected to the driving TFT. The organic light emitting diode includes a first electrode (which is connected to the driving TFT), an organic emitting layer and a second electrode. In the OLED display device, light from the organic emitting layer passes through the first electrode or the second electrode to display an image.
As known, both of the LCD device and the OLED display device according to the related art require the substrate including the array elements. The substrate here may be referred to as an array substrate.
The TFT according to the related art includes a semiconductor layer of amorphous silicon, poly-silicon or an oxide semiconductor material. The TFT including the semiconductor layer of poly-silicon or the oxide semiconductor material has an advantage in mobility such that it is widely used for the OLED display device. Recently, the TFT including the semiconductor layer of the oxide semiconductor material can be made with an improved fabricating process such that it is more widely used. In addition, a dual gate type TFT having improved properties than a single gate type TFT is introduced.
FIG. 1 is a schematic cross-sectional view of an array substrate for the related art OLED display device. A driving region DA and an emitting region EA are defined in each pixel region P among a plurality of pixel regions Ps.
As shown in FIG. 1, the OLED display device according to the related art includes an array substrate 1. For each of a plurality of driving regions DAs in the array substrate 1, a first gate electrode 15 is formed on a substrate 10, and a gate insulating layer 18 is formed on the first gate electrode 15.
In each driving region DA, a semiconductor layer 20, which is formed of an oxide semiconductor material, is formed on the gate insulating layer 18 to correspond to the first gate electrode 15, and an etch stopper 23, which is formed of an inorganic insulating material, is formed on the semiconductor layer 20. The etch stopper 23 includes semiconductor contact holes 25 exposing both ends of the semiconductor layer 20.
A source electrode 33 and a drain electrode 36 are formed on the etch stopper 23. The source and drain electrodes 33 and 36 respectively contact the semiconductor layer 20 through the semiconductor contact holes 25.
A passivation layer 40 including a first drain contact hole 43 is formed on the source and drain electrodes 33 and 36. A portion of the drain electrode 36 is exposed through the first drain contact hole 43. In addition, a gate contact hole "gch" exposing the first gate electrode 15 is formed through the passivation layer 40, the etch stopper 23 and the gate insulating layer 18.
An auxiliary drain electrode 56 contacting the drain electrode 36 through the first drain contact hole 43 is formed on the passivation layer 40. In addition, a second gate electrode 54 contacting the first gate electrode 15 through the gate contact hole "gch" is formed on the passivation layer 40. The second gate electrode 54 is spaced apart from the auxiliary drain electrode 56, overlaps the source electrode 33, and is closely located to the drain electrode 36.
The first gate electrode 15, the semiconductor layer 20, the source electrode 33, the drain electrode 36, the auxiliary drain electrode 56 and the second gate electrode 54 constitute a driving TFT DTr in each driving region DA.
A planarization layer 60 having a flat top surface is formed on the auxiliary drain electrode 56 and the second gate electrode 54. The planarization layer 60 includes a second drain contact hole 63 exposing the auxiliary drain electrode 56.
A first electrode 70 contacting the auxiliary drain electrode 56 through the second drain contact hole 63 is formed on the planarization layer 60. The first electrode 70 is positioned in the emitting region EA. A bank 71 overlapping an edge of the first electrode 70 is formed on the planarization layer 60. The bank 71 is positioned in the driving region DA and surrounds the pixel region P.
An organic emitting layer 73 is formed on the first electrode 70 and in the emitting region EA, and a second electrode 76 is formed on the organic emitting layer 73. The first electrode 70, the organic emitting layer 73 and the second electrode 76 constitute an organic emitting diode E in each emitting region EA.
In FIG. 1, the organic emitting diode E is formed on the substrate 10 with the driving TFT DTr. Alternatively, the organic emitting diode E can be formed on an opposite substrate. In this instance, the array substrate for the OLED display device includes the driving TFT and an electrode as a connection electrode.
On the other hand, the array substrate for the LCD device includes a TFT shown in FIG. 1 and a pixel electrode, which is connected to the TFT, with or without a common electrode. Namely, both the array substrate for the OLED display device and the array substrate for the LCD device include TFTs and electrodes. The TFT in FIG. 1 is a dual gate type TFT.
As illustrated above, in the dual gate type TFT, the first and second gate electrodes 15 and 54 are disposed under and over the semiconductor layer 20, respectively. In addition, the first and second gate electrodes 15 and 54 are in direct contact with each other and are electrically connected to each other.
A channel is securely formed in the semiconductor layer 20 in the dual gate type TFT such that an ON current property of the dual gate type TFT is improved in comparison to a TFT including a single gate electrode. In addition, a stain problem resulting from a non-uniformity of the TFT is decreased such that an image quality is improved.
However, there may be a problem in the operation of the TFT according to the related art. In the related art dual gate type TFT as shown in FIG. 1, an electrical short problem is generated between the drain electrode 36 and the second gate electrode 54 and between the source electrode 33 and the second gate electrode 54. As a result, the TFT is not properly operated.
In more detail, the passivation layer 40, which is formed of an inorganic insulating material, is formed between the drain electrode 36 and the second gate electrode 54 and between the source electrode 33 and the second gate electrode 54, and has a thickness of 2000 to 4000 angstroms. Each of the source and drain electrodes 33 and 36 and the second gate electrode 54 is formed of a low resistance metallic material such as copper (Cu), Cu alloy, aluminum (Al) or Al alloy (AlNd).
Particularly, when the source and drain electrodes 33 and 36 and the second gate electrode 54, each of which is formed of Cu or Al, are exposed to a relatively high temperature, e.g., 200 to 300° C., in a sputtering process or a chemical vapor deposition process, the material of the source and drain electrodes 33 and 36 and the second gate electrode 54 is migrated into the passivation layer 40 such that an electrical short problem is generated between the drain electrode 36 and the second gate electrode 54 and between the source electrode 33 and the second gate electrode 54. FIG. 2 is a picture depicting an example of such Cu migration into the passivation layer 40 causing an electrical short problem. This negatively affects the operation of the dual gate type TFT according to the related art.


One embodiment of the invention includes product comprising an elastomeric epoxy dry adhesive with a pull-off strength of 1-200 N/cm2 from a substrate and reversibly detached with a peel-off force less than 1 N/cm.

Gecko feet pads, with nanohair structures on them, are examples of smart dry adhesives. The working principle of the Gecko adhesion is that the nanohair structure allows the foot pad to make maximum contact with a counter surface regardless of its roughness and chemical composition. This is accomplished by nanohairs that are relatively long and protruding from the foot pad at an angle so that adjacent nanohairs can contact the counter surface regardless of its topography. The maximum contact further allows for accumulation of millions of small van der Waals (in the range of microNewtons) interactions between the Gecko foot pad and the counter surface, leading to an overall adhesion force (pull-off force) of about 10 N/cm2. When the detaching force is employed in a peel-off mode, however, the complete detachment is achieved gradually by overcoming small adhesion forces corresponding to very small areas. Thus, the adhesion is easily reversed. Overall, the attractiveness of the Gecko adhesion lies in the combination of adhesive strength (10 N/cm2), reversibility, and the ability to adapt to a variety of surfaces in terms of both the surface roughness and composition. The above unique features of the Gecko adhesion has stimulated scientific research efforts to produce synthetic smart dry adhesives that work using the same principle as the Gecko feet. Up to now, the two best synthetic Gecko adhesives show maximum pull-off adhesive strength of 3 and 10 N/cm2 towards glass. Both adhesives suffer from severe adhesion loss after only one or two attaching/detaching cycles, as a result of breakdown and the lateral collapse of the nano structures, with the latter referring to the adjacent nano hairs of the Gecko foot pad bonding to each other. In addition, synthetic Gecko adhesives are expensive to produce and large-scale manufacturing is practically too difficult.


A semiconductor light-emitting device, the device includes a substrate, a semiconductor stacked layer, a lead electrode and a lead, wherein the semiconductor stacked layer at least includes a N-type layer and a P-type layer, at least one of the N-type layer and the P-type layer has an opening, the opening is just beneath the lead; or includes a conductive substrate having a main surface and a back surface, an adhesive metal layer, a reflective/ohmic metal layer, a semiconductor stacked layer, a lead electrode and a lead sequentially deposited on the main surface of the substrate, the reflective/ohmic metal layer has an opening, the opening is just beneath the lead.

Semiconductor light-emitting devices are an important type of semiconductor device with a wide range of applications. For example, semiconductor light-emitting diodes (LED) have been used for indicator lights, signal panels, and traffic lights. Recently developed InGaAlN-based LEDs are expanding LED application to the domain of lighting. In order to achieve the objective of using LED for general lighting, it is essential to increase the efficiency of current LEDs. FIG. 1 illustrates the structure of a typical LED. In the figure, label "1" refers to a substrate, label "2" refers to a semiconductor epitaxial layer stack, label "3" refers to an electrode, and label "4" refers an electrode lead wire. Normally, an ohmic contact is formed between electrode 3 and semiconductor epitaxial layer stack 2. There is another electrode at the backside of the substrate. During operation, current is introduced from electrode lead wire 4 into semiconductor epitaxial layer stack 2 through electrode 3, exciting light emission inside the layer stack. The current then flows out of the device from the backside electrode. The light generated inside semiconductor epitaxial layer stack 2 is emitted from the upper surface (the downward propagated light is also emitted from the upper surface after being reflected). From the figure, one can see that the presence of electrode lead wire 4 blocks the light generated by the epitaxial layer stack situated underneath the electrode lead wire, thus preventing the light from being emitted outside the device. As a result, the light-emitting efficiency of the device is reduced.


According to an example, usage of a plurality of features of an application by users in each of a plurality of tenants may be accessed. Popularities of the plurality of features among the users in each of the plurality of tenants may be determined and a feature of the plurality of features to be promoted to the users in the first tenant may be identified based upon the determined popularities of the features. Additionally, a visual callout to the identified feature may be caused to be displayed to the users in the first tenant to promote the identified feature to the users in the first tenant.

Applications may include a number of features that are available for users to access and implement. Users, however, may not use many of the features because the users are often unaware of the features or how to use the features, or are accustomed to a particular way of implementing the applications. As such, many users overlook features that may result in greater productivity and/or enjoyment from using the applications.

Popularity-based promotion of application features


On the basis of a spreading factor obtained by despreading a control channel of received data by a control channel despreading unit, a spreading factor determination unit determines a transmission rate of the received data. User data subjected to despreading processing at a user data despreading unit is demodulated by a demodulator and temporarily stored in a demodulated data memory. The user data read from the demodulated data memory is decoded by a decoder, whereas the result of decoding by the decoder is supplied to a delay measurement unit, where a delay time relative to the above processing, of the user data is detected. A channel resource management unit manages the number of available resources at all times or in a constant cycle on the basis of transmission rates of respective radio channels detected by the spreading factor determination unit and delay processing times of the respective radio channels detected by the delay measurement unit.

1. Field of the Invention
The present invention relates to a base transceiver station employed in a radio communication system of a CDMA (Code Division Multiple Access) type, and particularly to resource management thereof.
2. Description of the Related Art
In a CDMA type radio system, various control information are transmitted as control channels, and user data such as voice data and packet data are transmitted as user channels. When such data are transmitted from a radio mobile station to a base transceiver station, the user channels are mapped onto an I axis and the control channels are mapped onto a Q axis respectively, followed by being QPSK-modulated in the mobile station. Further, they are subjected to spectrum spread modulation by spreading codes, followed by being transmitted to the base transceiver station. When the base transceiver station accepts a call from the mobile station, the base transceiver station receives the above spectrum spread modulated signal from the mobile station, despreads the control channels on the Q axis using the same spreading codes as the mobile station, and despreads the user channels on the I axis. A spreading factor (SF) of each spreading code used as transmission rate information of the spectrum spread modulated signal at its reception is extracted from each of the despread control channels. Then, phase control and coherent detection of each data channel spread-processed according to a transmission rate are carried out, followed by demodulation to user data. The demodulated user data are subjected to decoding processing such as an error correction, error detection, etc. (refer to, for example, a patent document 1 (Japanese Unexamined Patent Publication No. 2001-267959)).
A conventional control method for the base transceiver station will next be explained.
Upon communications between a mobile station and a base transceiver station under a radio communication system, the base transceiver station performs the transmission/reception of control information using a common channel (control channel) where, for example, a connection request (call) from a mobile station takes place, and shares parameters necessary to set each dedicated channel (data channel). When radio resources (resources necessary for transmission/reception) necessary to set the dedicated channels, and channel resources (i.e., a despread unit, a demodulator, a decoder, a memory, etc.) for the base transceiver station can be ensured, the base transceiver station performs the setting of each dedicated channel to the mobile station having made the connection request and starts communications of user data with the mobile station.
The base transceiver station performs reception of call setting information and setting processing in accordance with instructions issued from a radio network controller (RNC) corresponding to its host device. If, however, there is not enough free space for the channel resource of the base transceiver station, then the base transceiver station sends back reception disable information that a new call cannot be accepted, to the corresponding mobile station upon reception of the new call and does not perform the setting processing.
Thus, in order to make it possible to determine whether the call should be accepted, the base transceiver station performs the management of channel resources accommodable (i.e., allocable to a mobile station in which a call has occurred newly) therein. Such management relates to hardware and software processes, which are managed by the number of resources in advance every transmission rates available for uplink communications. Since the limited resources are applied statically in this management, a resource allocated to a call is not applicable to other call until the call is set free.
With the management of each resource in this way, a transmission rate of a communication signal (i.e., the above spectrum spread modulated signal) on a radio channel for a new call is detected when the new call is made. A decision is made as to whether the reception of this call is enabled according to whether the number of resources necessary for the transmission rate exists. However, the maximum transmission rate available for a set radio channel (channel corresponding to a spreading code in the CDMA system) is used as a transmission rate defined as a criterion as to whether the allocation of such resources is enabled. Even though the transmission rate becomes maximum among all held (i.e., set) radio channels, processes such as despreading, demodulation, decoding or the like of received user data on respective radio channels are performed without any delay so as to make it possible to ensure resources.
However, the uplink information (user data) decoded by the base transceiver station differ in parameter upon error correction processing or the like used in decoding processing, according to the type of applied data. With the difference between the parameters, resources for hardware to be utilized differ. Therefore, when a change in the type of data occurs in the uplink information from the mobile station to the base transceiver station where the uplink information is decoded, the resources for the hardware are switched on each occasion. The number of resources allocable to the corresponding radio channel is determined in consideration of even such a thing. Thus, the number of resources for the hardware is distributed to the mobile station having produced a call for a new connection request by giving consideration even to that a change in data type thus occurs in uplink information to be transmitted from now on. However, whether the number of resources should be distributed thereto (i.e., whether this call should be accepted) depends upon whether the number of resources available for the hardware at that time exists. That is, the number of processable channels differs depending on the number of resources for the hardware.
As a method for allocating the resource to the radio channel having accepted the call, there has been proposed a technique wherein a resource amount calculation table in which a symbol rate per each resource is represented by an uplink u-plane from a mobile station to a base transceiver station and a downlink u-plane from the base transceiver station to the mobile station, and a source amount calculation table indicative of the relationship between radio channel numbers and the number of resources are set, and a resource amount for the corresponding radio channel is allocated using such a resource amount calculation table (refer to, for example, a patent document 2 (Japanese Unexamined Patent Publication No. 2004-282469)).
According to the description disclosed in the patent document 2, a resource management table showing the relationship between signal processors and the number of resources available with respect to the same is set to perform resource management. The resource management table is retrieved based on the resource amount of the corresponding radio channel determined using the resource amount calculation table, and a signal processor having a vacant resource processable for the present radio channel can be selected.
When the radio channels are subjected to decoding processing (such as the settings of processing timings for a plurality of radio channels where the plurality of radio channels are decoded) by software, algorithms applied to the decoding are different in terms of the type of data or the like. Due to the difference between such algorithms, the time required to complete the decoding processing varies. Therefore, the number of channels accommodable (i.e., processable simultaneously) in the base transceiver station is not uniquely determined from only the transmission rate of each radio channel. Therefore, the storage capacity of the base transceiver station depends upon the throughput capacity of the decoder to make the best use of it. However, there is a need to define in advance the distribution of the number of resources set every data type applied to each radio channel, to the corresponding demodulator.
According to the above method for allocating the resources to the radio channels, even though the possible maximum transmission rate of each radio channel to which wireless communications are set is assumed, and the transmission states of all radio channels are simultaneously brought to the state of the maximum transmission rate, the storage capacities of hardware and software enough to simply enable the completion of processing within a prescribed time over all the radio channels. Therefore, the number of resources corresponding to each of the maximum transmission rates is allocated to each of these all radio channels.
On the other hand, the radio communication system such as the CDMA system or the like performs the transmission of user data through radio channels between the mobile station and the base transceiver station only where the transmission of the user data is required, in order to make good use of the limited radio resources. When there is no user data to be transmitted, the transmission of only the minimum information, i.e., control channels necessary to maintain the connections of the radio channels is performed. Described specifically, a transmission rate on a radio transmission line between a mobile station and a base transceiver station is reduced. Further, only closed-loop transmit power control information and transmission rate information used to control and hold transmit power between the mobile station and the base transceiver station to a proper value, and an identifier of a transmission rate, which is capable of identifying the presence or absence of user data, are repeatedly transmitted and thereby the connections of the radio channels are maintained.
Incidentally, voice data, packet data and the like are considered as the user data applied to such a radio communication system. However, when, for example, transmit user data on a radio channel is of voice data, a silent section exists about 50%. When the silent section is detected, the transmission of user data onto its corresponding radio transmission line is stopped on the transmitter side (the state of transmission of the user data is discontinued), and only control information such as the transmit power control information or the like on the radio channel is transmitted. Even in the case of the packet data, communications are carried out at a high transmission rate only where the acquisition of desired data such as download is required. When the acquisition of data is not necessary, the transmission of user data through the radio transmission line is stopped in a manner similar to the voice data, and the switching of a transmission state is performed in such a manner that only the control channel is transmitted at a low transmission rate. Thus, control on the switching of the transmission rate is dynamically carried out according to the presence or absence of the user data.
Thus, in the radio communication system for dynamically controlling the transmission rate, when the management of the channel resource (resource for the radio channel) in which its maximum transmission rate is assumed with respect to the radio channel as described above, is executed at the base transceiver station, data transmission is not carried out at all times at the maximum transmission rate over all the radio channels, and the transmission of data at the maximum transmission rate is rather rare. Therefore, a problem arises in that even though the number of resources is allocated to each radio channel according to the maximum transmission rate, at least some thereof is not used and the processing performance of the base transceiver station is not used to the fullest extent.


A high power electromagnetic pulse driver for generating sub-microsecond rise time pulses having energy contents greater than 1 joule includes an electromagnetic pulse compressor and an electromagnetic shock line for compressing the leading edges of those pulses. The shock line may use non-linear materials whose permeability or permittivity vary greatly with varying field strength. One material whose permeability varies by a useful amount is metglass, an amorphous alloy of silicon and iron. The high power electromagnetic pulse driver may drive gas discharge lasers.

In applications such as driving a discharge laser or a pulsed radar, there is a need for producing short, high energy pulses at a high repetition rate. For example, a driver for a copper vapor laser or a CO.sub.2 laser may require pulses of approximately 1 joule or greater, of approximately 10-20 nanoseconds duration and having rise times of 1 nanosecond or less. Such lasers may be utilized in uranium isotope separation and in a broad spectrum of other research, industrial, government and other applications. One high voltage pulsed power source suitable for use in such applications is shown in HIGH VOLTAGE PULSE POWER SOURCE, U.S. patent application ser. no. 07/778,313, filed Oct. 16, 1991 and incorporated herein by reference.
As noted therein, earlier thyratron-based pulse drivers were limited by the performance of the thyratron. One important limitation on thyratron performance is speed. Thyratrons do not have a fast enough rise time to provide multiple-joule pulses having durations in a range of several nanoseconds. Likewise, even the high voltage pulse power source of the U.S. patent application ser. no. 07/778,313 referenced above does not produce pulse rise times in the range of several nanoseconds or shorter.
A pulse rise time may be reduced by passing a pulse through an electromaqnetic shock line. A discussion of the general theory of electromagnetic shock lines is provided in Electromaqnetic Shock Waves, by D. G. Katayev, originally published in the U.S.S.R. by Sovietskaye Radio, Moscow, 1963. An English edition was first published by Iliffe Books, Ltd., London, 1966. The shock lines described therein are capable of operating in the 1/2 MW power range on only 2-3 nS output pulses. However, the power-handling capability of these lines, the output pulse rise time, and the power dissipation in these lines is unsatisfactory for current applications.
It is a general aim of the present invention to produce high power pulses in the nanosecond duration range or shorter, having high energy contents.
Another general aim of the present invention is to provide an apparatus capable of reducing the rise time of high power pulses in the nanosecond duration range from several nanoseconds to hundreds of picoseconds, without a significant loss of power.

High power electromagnetic pulse driver using an electromagnetic shock line


A bed for supporting a patient having a seat panel and a back panel coupled together by a joint assembly that allows the panels to rotate about an axis coincident with the patient's hip joint.

Hospital bed designs have recently been undergoing a transformation. Early beds were very basic devices providing limited patient support and care features. More recently, bed designs have been taking advantage of technological developments to provide improvements in bed articulation, mattress inflation, patient access, convenience and control. The following patents illustrate some of the designs that are currently known.
1. Pneumatic System
Valves are an integral part of a mattress inflation system. Recently, valves have been designed in which a metal alloy that changes shape in response to a change in temperature is used as the valve actuator. In U.S. Pat. No. 3,540,479 issued to Thompson for a "Heat Motor and Valve", a valve using a heat-expanding rod to open a biased-closed valve seat is disclosed. Willson et al., in U.S. Pat. No. 3,613,732 entitled "Temperature-Responsive Valve Operators", discloses various valve configurations utilizing temperature-responsive operators made with a shape-memory alloy such as a nickel and titanium alloy. The disclosed configurations include single and double poppet designs, as well as coaxial, single poppet designs.
U.S. Pat. No. 4,130,265 issued to Sakakibara et al. for "Electrically Operated Switching Valve" discloses the use of a warped plate controlled by a heat-activated element for selectively valving opposing ports relative to an intermediate port. Suzuki, in U.S. Pat. No. 4,736,587 entitled "Shape-Memory Electromechanical Drive" discloses the use of two shape-memory springs to move a slide member to couple alternate outer ports with a central port.
A valve member that alternately opens and closes by heat-generating electrical current acting on a spring-biased linear alloy element is disclosed in U.S. Pat. No. 4,973,024 issued to Homma for "Valve Driven By Shape Memory Alloy". Hori, in Japanese Pat. No. JP61-17789 entitled "Valve Device", discloses a valve-opening device activated by a shape-memory alloy spring. The valve is held closed by a coaxial bias spring.
These valve assemblies provide for effective valving, but there remains a need for a valve assembly that is able to inversely vary the flow of air or other fluid through respective inlet and outlet ports, and to independently control the flow of air through input and output ports, and that is self-contained for convenient installation and removal from a fluid-chamber housing.
Inflatable mattress cushions or cells are often connected to a support surface of a base platform or frame. This connection may be provided by a connector having an inner channel or passageway, that attaches the cell to a port extending through the support surface. Further, it is known to connect two cells together with a passageway formed in the connection to allow air to flow between the connected cells. An example of such an arrangement is disclosed by Pertchik in U.S. Pat. No. 4,255,824 for "Cushion for Decubitus Ulcers". Pertchik discloses a seat cushion formed of a plurality of elongate cells that are connected at contact points to provide inflation of all the cells from a single inlet.
Hunt et al., in U.S. Pat. No. 4,525,885 entitled "Support Appliance for Mounting on a Standard Hospital Bed", discloses male and female parts of a connector assembly for connecting mattress cells to a mattress base inlet or outlet. Another form of connector for a mattress cell is shown in FIG. 6 of U.S. Pat. No. 4,949,413 issued to Goodwin for "Low Air Loss Bed".
Hunt et al., in U.S. Pat. No. 4,935,968 entitled "Patient Support Appliances" also discloses a connector of an air tube to a housing (FIG. 4). This is a quick release connection to allow rapid deflation for cardiac arrest procedures. In U.S. Pat. No. 4,949,414 entitled "Modular Low Air Loss Patient Support System and Methods for Automatic Patient Turning and Pressure Point Relief", Thomas et al. also disclose in FIGS. 5 and 6 a connector for connecting a mattress cell to the platform.
These connectors are constructed to be usable in a specific application, but do not permit use in various connections. For instance, there remains the need for fluid-transmitting connectors that are usable for coupling a cell to a support platform and for coupling cells together, with the integrity of the base cell remaining when a satellite cell is disconnected. Further, there is a need for a connector that can accommodate a reducer for connecting a tube to a cell.
When used on an articulating bed, the fluid supply and exhaust systems used for inflating and deflating mattress cells must either be formed integrally as part of the bed platform, or must be provided by external hoses or ducts. These arrangements result in bending and wear of connecting hoses, and exposure of external tubes to wear and contact by other moving parts.
The present invention makes use of expandable passageways, similar to bellows, for coupling manifolds supported on adjoining, articulating panels. Bellows-like support cells are known to be used in hospital beds. For instance, Hunt et al., in U.S. Pat. No. 4,099,276 entitled "Support Appliances Having Articulated Sections" shows the use of inflatable bellows to raise and lower the head end of a bed platform. Similar structures are also shown in patent '885 issued to Hunt et al., identified previously. A bellows-type mattress cell is disclosed by Sato in U.S. Pat. No. 4,542,547 entitled "Pneumatic Mat with Sensing Means".
There thus remains the need for a flexible passageway structure that can connect air passageways of adjoining bed panels, that conforms with the panel structure, is reliable, and expands and contracts in response to movement of the adjoining panels.
There also is a need for a simple efficient structure for conveying pressurized and exhaust fluids to mattress cells, and along articulated panels. As was mentioned, flexible tubes are usually used to connect mattress cells to an air supply and exhaust port. For example, Hunt et al., in patent '885, and Goodwin, in patent '413, disclose the use of a flexible tube serving each mattress section. Goodwin shows them as being external to the bed platform, while Hunt et al. show them to be within the platform. Also, Evans, in U.S. Pat. No. 4,864,671 entitled "Controllably Inflatable Cushion", discloses individual cushions inflated in groups or zones with supply lines and exhaust lines serving each zone being controlled by a three way valve.
U.S. Pat. No. 4,945,590 issued to Ogura for "Valve for Fluid Mat and Apparatus for Controlling an Attitude Assumed by Fluid Mat", discloses air mattress supply ducts that are positioned between relative positive and negative pressure air chambers. Separate solenoid valves connect each air supply duct with each of the air chambers.
Harkleroad et al. discloses, in U.S. Pat. No. 4,993,920 entitled "Air Mattress Pumping and Venting System", a pressure control system in which sensors control a venting valve and a pump for maintaining the mattress pressure between predetermined high and low values. The use of a valve having a rotatable disk for alternately connecting air supply and discharge pipes to two mattress sections is shown in U.S. Pat. No. 5,035,016 issued to Mori et al. for an "Air-Mat Apparatus".
With the development of elaborate inflatable mattresses and articulating support platforms, it became difficult to take immediate action when a patient needed CPR or other procedures to treat a life-threatening condition. Various means have been developed to make the bed become a hard, flat surface to facilitate, rather than impair these procedures.
For instance, in British Patent No. GB 2 141 333 entitled "Low Air Loss Support Appliance", Hunt et al. disclose in FIG. 2 and on page 2, lines 67-74, a quick release manifold that allows deflation from all ports.
In patent '968, Hunt et al. disclose an air distribution chamber for supplying air to mattress cells. An exhaust plate on the chamber is manually moved to open an exhaust hole for rapidly deflating the mattress. An air pump must be separately turned off, but a switch activated by the handle to the exhaust plate transmits a signal to open the exhaust valves used on the head & foot articulating bellows. FIG. 12 of patent '414 issued to Thomas et al. discloses the use of a CPR switch connected to a circuit board.
Various forms of cushions and mattresses have been designed in order to provide improved support for a patient. Viesturs et al., in U.S. Pat. No. 4,534,078 entitled "Body Supporting Mattress", disclose an elongate inner cell supported on a pad having a peripheral inflated tube. Generally U-shaped cells that alternate and are offset for use in turning a patient are disclosed in U.S. Pat. No. 5,003,654 issued to Vrzalik for a "Method and Apparatus for Alternating Pressure of a Low Air Loss Patient Support System". In U.S. Pat. No. 4,768,249 entitled "Patient Support Structure", Goodwin discloses a more conventional low air loss mattress formed of upright cells extending across the width of the bed.
Such mattresses as shown by Goodwin and Vrzalik are prone to bend or lean into an adjoining cell location when the adjoining cell is deflated. This tends to reduce the effectiveness of controlling the support pressure and location, which is necessary in the avoidance and treatment of bed sores, and also in the articulation of the bed.
It is also known to provide mattresses that have multiple layers. Grant, in U.S. Pat. No. 3,674,019 entitled "Dual Layer Cellular Inflatable Pad", describes a pad formed of offset layers of interdigitated inflatable sections. Welch, in U.S. Pat. No. 4,193,149 entitled "Beds and Mattresses", discloses a similar mattress, except the layer cells are aligned and separated by a preformed foam. Such mattresses assure resilient support for a patient, but provide limited control of support by adjacent cells.
Various cushions are also known for restraining a person. An elaborate example is disclosed by Boyce in U.S. Pat. No. 3,218,103 entitled "Pneumatic Restraint System". This patent discloses a chair having inflatable bands shiftable in position for selectively restraining a person. A restraining device that is releasably attached to a support platform for placement across the body of an infant is disclosed in U.S. Pat. No. 4,205,669 issued to Hamann for "Diaper-Changing Aid".
There thus remains a need for a means for restraining persons on a bed. In particular, it is desirable to have lateral cushions that conform to the sides of a patient, and selectively inflatable cushions that are positionable over a patient for keeping the patient in the bed.
The pneumatic system of a conventional hospital bed typically includes a single pressurized air source with valves and ducts or other conduits providing distribution to the cushions in a mattress. Examples of such systems are provided in U.S. Pat. Nos. 4,799,276, 4,949,413, 4,993,920 and 5,044,029. A review of these patents shows the extent that people have gone in controlling air flow from a single source. The air flow is divided and distributed to cushions supported on several relatively articulatable panels. There typically are elaborate valves to control the amount of air flow and extensive flexible conduits and/or plenums to distribute the allocated air to each set of cushions. The air distribution system described herein with reference to FIG. 2 is an example of a more simplified air distribution scheme, but even it imposes significant structural requirements on the bed panels to form the air flow paths.
The manner in which the cushions are attached to or supported on the platform panels may also be involved. For instance U.S. Pat. Nos. 3,879,776 and 3,909,858 illustrate elaborate structures for attaching inflatable cushions to a bed platform for anchoring the cushions and providing an air passageway for inflating them.
There thus is a need for a pneumatic system that is simple in structure, readily serviced, and provides pressure control to individual sets of cushions supported on relatively articulatable panels.
2. Footboard Gate
In most any patient care environment in which the patient is bedridden, it is desirable, and often necessary to provide support for equipment, documents, and other materials. Where it is sufficient to use a shelf or horizontal platform for this a movable tray on a stand separate from the bed is often utilized. In order to limit the amount of accessories around the bed or to provide a convenient table in the vicinity of the bed, various schemes have been developed.
Slivoski, in U.S. Pat. No. 3,327,328 entitled "Mattress Extension", discloses a bed having a foot-end kick board that swings upward to form a platform. In U.S. Pat. No. 3,344,445 entitled "Side Panel Construction for Stretcher-Beds", Crawford discloses a side guard panel that converts into a platform.
A board extending across an intermediate portion of a bed is disclosed by Donald in U.S. Pat. No. 535,945 entitled "Detachable Foot Rest and Table for Beds". The board is positionable as a table, and may be pivoted down to act as footboard for a person sitting in bed or extended beyond the foot of the bed for storage. A somewhat similar concept is disclosed in U.S. Pat. No. 4,724,555 issued to Poehner et al. for a "Hospital Bed Footboard". This footboard pulls out and pivots up to form a horizontal table. An alternative embodiment simply swings up to a horizontal, over-floor position and can slide partially over the foot of the bed.
3. Stand-Up Board
The extended articulation capabilities of some beds includes the ability to raise the head of the bed, and correspondingly lower the foot of the bed until the bed is sufficiently inclined to allow the patient to exit the bed from a standing position. In order to accommodate this, it is necessary for the bed to have a footboard that is strong enough to hold the weight of the patient, and yet small enough that it will allow the mattress to be lowered near the floor.
A bed developed by England and described in U.S. Pat. No. 3,997,926 entitled "Bed with Automatic Tilting Occupant Support", is positionable in a stand-up position. A foot rest is shiftable between an inoperative position spaced from the end of the bed to an operative position adjacent to the end of the bed when the bed is inclined. The foot rest is disposed at an obtuse angled relative to the platform.
This footboard has limited capabilities, and is always a part of the bed platform. Considering the infrequency that beds are used to raise a patient to a standing position, it is desirable to have a footboard that is adjustable, can serve different functions, and can be removed if desired.
4. Headboard
When CPR or other emergency procedures are performed on a patient the attending personnel desire to be as close as possible to the patient. Surgical tables, for instance, are built without any form of side barriers. Beds, however, are normally used to support a patient when such procedures are not being performed, and therefore have restraining elements, such as side rails, headboards and footboards. It is conventional to provide a side rail that collapses below the level of the mattress to facilitate care by a nurse, doctor or other attendant. The number of attendants that can reasonably access a patient is limited to the number that can conveniently stand along the sides of a bed. There is thus a need for providing increased access to a patient supported in a bed.
Also, for some forms of equipment, tables or trays are not adequate. For instance, intravenous (IV) equipment typically must be suspended above a patient to allow gravity to convey a fluid from a container to an intravenous needle. Also, traction devices must have an anchor connected to the bed frame. These requirements have led to other support configurations.
In an article entitled "Problems of Patient Support: The Air Fluidised Bed as a Solution", pp. 269-275, Hargest discloses in FIGS. 1 and 2 conventional traction and equipment-supporting apparatus. Peck et al., in U.S. Pat. No. 3,063,066 entitled "Sidegate for Beds", discloses an extension rod mounted to a corner post cap for supporting equipment.
The use of telescoping posts or members in beds are well established. U.S. Pat. No. 3,081,463 issued to Williams et al. for "Motor Operated Hospital Bed" discloses telescoping corner posts supporting end panels. A cable system provides motorized activation. Similarly, U.S. Pat. No. 3,220,020 issued to Nelson for an "Adjustable Height Bed", discloses A bed with leg posts having a spring-biased telescoping outer sleeve that raises and lowers with the bed platform. Hillenbrand et al., in U.S. Pat. No. 3,237,212 entitled "Retractable Bed", also discloses a bed with leg posts having spring-biased telescoping outer sleeves that raise and lower the bed platform.
U.S. Pat. No. 3,742,527 was issued to Johnston et al. for a "Hospital Bed" having hydraulically driven telescoping corner legs and a guard rail with manually telescoping support legs. In U.S. Pat. No. 4,686,727 entitled "Convenience Bar Assembly for Hospital Bed", Wilkinson discloses a vertical bar and cross member for supporting various controls and patient equipment.
The equipment supports thus known in the art are either disposed on the bed in usable position, where they get in the way of the patient and nurses when not used, or they must be removed and stored, and thus may not be readily available when needed.
5. Weight-Sensing System
One of the advantages of the newer technologies has been the ability to monitor the patient while in the bed. An example of this is a system in which the weight of the patient is monitored while on the bed. The weight of the bed itself is compensated for in order to derive the patient's weight.
One such system is used in a bed made by Kinetic Concepts,Inc. of San Antonio, Tex. That bed has a display for showing the patient weight and change in weight.
The conventional structure providing this capability is the use of a stress gauge at each of four corners of the bed. Examples of this structure are disclosed in U.S. Pat. No. 4,669,136 issued to Waters et al. for "Combination Hospital Bed and Surgical Table" (col. 5, lines 13-25, col. 1, lines 58-60); and U.S. Pat. No. 4,926,951 issued to Carruth et al. for "Weigh Bed". This latter patent discloses a weigh system in which a load cell at each of four corners is supported on a base frame using a ball to transmit the vertical weight without creating any lateral torque. Horizontal position is maintained by three tie rods connecting the weigh frame to the base frame to prevent twisting of the weigh frame for certain patient or bed orientations.
One problem with such systems is that warp inevitable exists in either or both the bed frame or the base frame. This warping results in inconsistencies in the stress on the stress gauges, and therefor produces inherent inaccuracies or complexities that must be compensated for in some other way.
Not only is it useful to measure the weight of a patient without requiring the patient to leave the bed, it is also desirable to monitor the movement of a patient on the bed. Fleck et al., in U.S. Pat. No. 4,539,560 entitled "Bed Departure Detection System", discloses the use of tape switch detectors in a mattress to detect a person's departure from a bed. Restlessness of a person in the bed can be detected through the use of two or three tape switches.
Peck et al. devised a system for sensing the departure of a patient from the bed of the invention by a decrease in pressure in a lower bladder, as is disclosed in U.S. Pat. No. 4,803,744 entitled "Inflatable Bed".
6. Control Unit
As the complexity of beds and patient care systems increase, the complexity of control of the patient support system also increases. The control of some features, such as bed configuration, are made available to the patient, and control of other features, such as mattress pressure, air flow and temperature, are made available only to the attending personnel. Various control designs have been developed to accommodate these two control needs.
An air suspension bed identified by the proprietary name TheraPulse.TM. of Kinetic Concepts,Inc. of San Antonio, Tex., includes a hand-held bed controller provided with a hook for hanging the controller on a side rail. The bed also has controls extending from the face of the footboard for use by attendants. Pauna discloses a control panel mounted on a guard rail in U.S. Pat. No. 4,821,348 entitled "Convertible Bed and Bathroom Combination".
In U.S. Pat. No. 3,839,753 entitled "Hospital Bed", Benoit et al. disclose a nurse control panel located in the footboard and covered by a panel cover. These controls are in addition to patient controls. Drew et al. disclose various control units built into guard rails in U.S. Pat. No. 4,183,015 entitled "Side Guard for Bed Including Means for Controlling Remote Electrical Devices". This patent also mentions that removal, interchange, and replacement of the various controls is possible since the various controls are modular components. The controls may be easily replaced if service is required, or moved from one side to the other depending on the physical affliction of the patient. In patent '654, Vrzalik also discloses a control unit attached to the bottom of the footboard and control switches mounted in the footboard.
Except for the pendant control unit of Kinetics Concepts, such control units are mounted in fixed positions. The pendant control unit requires two hands to use, and is limited to controls made available to the patient. There thus remains the need for a controller that provides both attendant as well as patient controls that is variable in position and even capable of being hand held or removable in order to clear the patient area of the bed.
7. Transport Guide Wheels
One of the concerns with the newer, more elaborate beds is the strength and agility attendants need to maneuver them to different locations within a hospital. Typically, beds are provided with a wheel at each corner, with each wheel being free to turn about a vertical axis. This wheel arrangement is convenient for adjusting the orientation of a bed within a room, but makes turning corners and traveling along a straight line, such as when moving down a hallway, difficult.
Paramedic gurneys exist that have a fifth, center wheel that is fixed in alignment with the length of the gurney and is slightly below the plane of the four corner wheels. This assures that the fifth wheel is always in contact with the floor. However, the resulting rocking effect when weight is shifted from one end to the other is particularly undesirable in a permanent bed.
There is thus a need for a wheel system for hospital beds that allows maneuverability and yet assists in the movement of the bed significant distances.
8. Guard Rail Elevation System
As has been mentioned, beds typically have guard rails that can be fixed in a position above the mattress level, in order to keep patients from inadvertently exiting the bed. During times of attendance, it is desirable to remove the guard rail from its position. This is typically accommodated by making the guard rail removable or, more commonly, adjustable so that it can be pivoted or otherwise lowered below the level of the mattress.
One way that guard rails are lowered is by the use of telescoping support members, such as is described in U.S. Pat. No. 4,439,880 issued to Koncelik et al. for "Geriatric Bed Construction with Sideguards".
Cable and pulley systems are also used in various movable bed mechanisms in order to facilitate movement of a portion of the bed. For instance, Williams et al. disclose a cable-activated telescoping end panel in patent '463. Hunt et al., in patent '276, disclose the use of a cable and spring to operate a valve controlled by rotation of a pulley around which the cable is wound.
As is described in U.S. Pat. No. 4,747,171 entitled "Hospital Bed Rail Assembly", Einsele et al. developed a rail that pivots sideways to a lower position. It includes a spring, a cable and a cam link to resist gravity when lowered and raised.
There remains the need for a heavy duty side guard that raises and lowers in place, and is easy to operate with one hand.
9. Swing Arm Extension Brace
Hydraulic operation provides a readily controlled way to move articulating bed members. For example, Morrison developed a hydraulic ram for moving a pin resting on the edges of travel slots, as is shown in U.S. Pat. No. 3,462,772 entitled "Center-Pivoting Bed". This structure is confined to movement in the slots. Where a hydraulic arm is free to pivot it can experience a large bending moment when extended horizontally. It is therefore desirable to take advantage of the controllability of hydraulic arm movement while minimizing the size of the arm necessary to support a leveraged weight that can exist on the arm.
10. Platform Joint
Healthy people typically spend approximately one third of their time sleeping. People of what may be considered less than optimum health spend even greater amounts of time reclining. Beds of various forms have been developed in order to provide comfort to the user. This is particularly true of patients in hospitals and health care facilities, as well as those in homes who, for various reasons, are bed ridden.
Once one is in bed for extended periods of time in a situation or condition that does not allow movement in order to maintain comfort, complications, such as bed or pressure sores may develop. One way that this condition has been alleviated is to build beds having support surfaces that can be moved into various orientations and configurations. Representative examples of such beds are disclosed in U.S. Pat. Nos. 3,081,463 issued to Williams et al.; 4,038,709 issued to Kerwit; 4,099,276 issued to Hunt et al.; 4,371,996 issued to Nahum; 4,745,647 issued to Goodwin; 4,935,968 issued to Hunt et al.; and 5,023,967 issued to Ferrand; and French Pat. No. 87 16722 issued to Pupovic.
Each of these patents disclose beds having platforms formed of a set of panels that pivot for assuming configurations corresponding to various positions of a person's legs and torso. Each of these provide a back panel that supports a person's torso and a seat portion that supports the person's hips or hips and thighs.
These panels are typically hinged together or caused to pivot about a fixed joint corresponding to the hip joint. It has been observed that the surface length of the buttocks increases when a person moves from a flat reclining position to a sitting position. Fixed joints do not allow for this variation in body surface length, thereby requiring the reclining person to adjust her or his body to accommodate it. If the person is immobile, such accommodation is not possible. There therefore remains a need for a bed interpanel joint that is not fixed, but rather compensates for changes in the body surface during bending.
11. Hydraulic Valve
Many different forms of hydraulic valves exist for controlling fluid flow and fluid pressure. These valves typically involve a gate or plunger that closes an opening or other fluid passageway when in a closed position, and rapidly opens to relatively full flow conditions. There is thus very little intermediate control of the fluid flow.
In order to control fluid flow rate over a range of positions of adjustment, proportionally adjustable hydraulic valves have been developed. These valves provide for continuous variation of a fluid opening over a range of adjustment positions. Although the change in opening varies proportionally with adjustment position, the relationship between the two is very complex, with control determined typically by measurements of the fluid flow or the effect of the fluid flow, independent of adjustment position.
Articulating beds, and in particular hospital beds may use a hydraulic system to control movement of a support surface, such as a bed platform or hinging panels forming the platform, relative to a base supported on a floor. The platform may be moved as a unit, or the panels may move relative to each other. In such a bed, it is desirable to vary the speed of articulation of the support surface. For instance, it is desirable to raise the head panel slower than it is lowered. If the bed is capable of standing up a patient, it is desirable to use different stand up speeds for patients with different conditions.
It is useful to tilt a bed from side to side. For patients with pulmonary complications, tilting the bed from side to side slowly for long periods of time helps them breathe. However, if a bed needs to be tilted to position a patient for transfer to a stretcher, the bed must be tilted more quickly. Also for emergency applications, such as CPR or Trendelenburg, it is desirable to get the bed in a particular configuration very quickly. Since the bed could be in any allowable configuration at the time of the emergency request, the cylinders must all move at one speed for normal use, and another speed for emergency use.
It is seen that speed control over a wide range is desirable. Conventional valves typically of the spool type and have a wide dynamic range of operation. The portion of the range applicable to articulation speeds for beds is a small portion of that range. These valves also have flow rates that vary relative to valve shaft position according to complex equations. As a result they are themselves expensive and also require expensive systems to control them.
There thus is a need for an hydraulic articulating system that provides control within a limited range that is economical, and is controllable simply.
12. Platform Support
Various apparatus have been developed for supporting a bed platform. Current designs provide for changing the elevation and attitude of the platform relative to the base frame. Conventional systems use linear drives on parallel linkages or one or more hydraulic cylinders positioned to change the pitch and roll of the bed relative to a central universal joint.
A simplified platform support system was developed by Ferrand, as disclosed in U.S. Pat. No. 5,023,967, that involves a triangulation support system providing full platform articulation using three platform supports. The patent discloses the use of a universal joint mounted to the platform and supported on two opposing hydraulic arms. A pair of laterally opposing side arms are spaced from the universal joint. Coordinated adjustment in the lengths of the various hydraulic arms adjusts the three basic forms of platform orientation: pitch, roll and elevation.
Although providing a simple and effective system for articulating a platform, the three-axis support system as disclosed by Ferrand requires the use of two heavy-duty base hydraulic rams for supporting the universal joint. A compact universal joint, as disclosed, results in a mechanically weak point when the forces of an articulating bed platform are applied to it. By attaching the upper ends of both base rams to the universal joint, the available range of motion of the platform is equal to the adjustable length of the rams. Further, by mounting the two side arms to the base frame or to the base of the adjacent base ram, elevation changes in the bed are further limited by the length of throw of the two side arms. The attachment of the universal joint and the side legs to different, relatively hingeable panels also requires the use of a control system that must account for changes in orientation between the associated panels. There thus is a need for a three-axis support system that is more economical to produce and easier to use.
13. Multifunction Control System
As beds become more sophisticated with an increasing variety of different features, the use of the various features becomes more complicated and it becomes increasingly difficult to coordinate the various features and keep track of the state each feature is in at a given time. Such coordination becomes increasingly important when the bed is used to support a patient in a critical condition.
Beds presently exist which allow an attendant to lockout the control of bed movement by the patient in order to assure that the bed is maintained in a selected support configuration. An example is where the patient is held in traction and the orientation and firmness of the mattress must stay the same. Also, if the bed has an equipment-support table that extends over the mattress, certain movements of the mattress could upset the table. As yet another example, it would be unsafe to tilt the mattress sideways if one or more of the "downhill" guardrails is not in an upright position. There is therefore a need for a bed having controls that assist in the coordination of various features of the bed to assure proper patient treatment and safety.


A wiring and power distribution device for a cabinet housing electronic equipment. The distribution device includes a plurality of compartments. Each compartment adapted to contain an electronic component, such as an uninterruptible power supply, a power-conditioning device, or a power distribution center containing circuit breakers. The distribution device also includes a cooling compartment, including a fan or passive convective chimney arranged to cool the interior of the cabinet with ambient air. The distribution device provides a single input point for power and signal wiring, and at least one output point for connection to the electronic devices contained within the cabinet.

It is known to provide a rack or cabinet in which electronic components may be mounted. Existing racks may provide surge suppressors or power strips integrated into the rack; components may be plugged into these strips to make movement of the rack or cabinet more convenient. However, components mounted in such cabinets must still be wired individually to one another and to a power source which is typically located external to the rack or enters the rack from multiple locations.
Also, installation personnel must connect wiring to the rack or cabinet, as well as the components, in the field, after the electronic components are integrated into the cabinet. The field installation personnel must then work inside the cabinet to interconnect the components.
Current wiring systems are not well coordinated or designed for ease of installation and consistency, while also permitting ready access to wired components.
A need, therefore, exists for a wiring distribution device that provides central wire management of components for ease of installation in the field.

Wiring distribution device for an electronics rack


A new cultivar of Leucanthemum plant named ‘Real Sunbeam’ that is distinguishable by tight clumping basal branching and upright plant habit, non-fading yellow flowers held on very strong flower stems and whose ray florets are arranged in two to three rows, and a large disc comprised of dense arrangement of deep golden disc florets is disclosed.

The present invention relates to a new and distinct cultivar of Leucanthemum commonly known as Shasta daisy, which is grown as an ornamental plant for use in the garden and landscape. The new cultivar is known botanically as Leucanthemum×superbum and will be referred to hereinafter by the cultivar name 'Real Sunbeam'.
Leucanthemum is a genus within the family Asteraceae in which the commonly referred to "flower" is botanically the inflorescence which is comprised of outer showy ray florets surrounding smaller disc florets.
'Real Sunbeam' arose and was selected from an ongoing breeding program which is conducted by the inventors at the inventors' nursery in West Sussex, United Kingdom. The breeding program commenced in 2006 with the aim of developing new and improved commercial varieties of Leucanthemum. 'Real Sunbeam' is a seedling selection that resulted from the controlled pollination in 2011 of a single plant of the inventors' proprietary Leucanthemum seedling code 'L1025-6' (unreleased and unpatented) as the female parent, using pollen from a single plant of the inventors' proprietary Leucanthemum seedling code 'L1045-5' (unreleased and unpatented) as the male parent. The inventors selected 'Real Sunbeam' in 2012 based on the criteria of tight clumping basal branching and upright habit, non-fading yellow inflorescences held on very strong flower stems, ray florets typically arranged in two to three rows, and a large disc comprised of dense arrangement of deep golden disc florets.
'Real Sunbeam' was first asexually propagated by the inventors in West Sussex, United Kingdom in 2012 using the method of vegetative division and subsequently by basal shoot cuttings. Since that time under careful observation 'Real Sunbeam' has been determined uniform, stable and true to type in subsequent generations of asexual propagation.


In a semiconductor memory system, an SDRAM comprises a memory cell array 101 which is divided into a plurality of cell array blocks, a column decoder, a row decoder, and a sense amplifier circuit. In the SDRAM, a first operation mode with a first cycle time is set when successive access within a cell array block is conducted, a second operation mode with a second cycle time shorter than the first cycle time is set when successive access covering the cell array blocks being apart from each other is conducted and a third operation mode with a medium cycle time is set when successive access covering the cell array blocks adjacent to each other is conducted. With the above constitution, a high speed access can be realized without provision of a specific accessory circuit while suppressing overhead for a semiconductor chip size.

The present invention relates to a semiconductor memory system using a DRAM or the like which can realize a high speed access.
A DRAM has been developed in integration to the highest level among MOS semiconductor memories because of the simplicity of a memory cell in a comparative sense and is now used as a main memory of all kinds of computer based apparatuses. On the other hand, there have been progresses to improve memory performance being driven by the rapid increase in capabilities of a microprocessor (MPU) in recent years: various kinds of DRAMs each provided with a high speed data cycle function have been proposed and some are already in early stages of mass production. Typical examples are the so-called synchronous DRAM (SDRAM) in which all I/O data are stored or retrieved in synchronism with a system clock and a double-data-rate SDRAM (DDR-SDRAM) which makes it possible to use both edges of a clock pulse as triggers for access though similar to the former in terms of operation, and the like. In addition to the above described DRAMs, a RANBUS DRAM (RDRAM) (under specifications of Rambus Inc.) in which data transfer is enabled at a high speed with a protocol-based command, and the like have also been developed and a trend in which a conventional asynchronous DRAM is replaced with a synchronous DRAM can be assured to be a necessity in the future.
A characteristic of such a synchronous DRAM is that the maximal bandwidth is operated at a very high speed. As the maximal bandwidth of the latest SDRAM versions, for example, 100 Mbps has been achieved. A DDR-SDRAM and a R-DRAM are estimated to reach 200 Mbps and 800 Mbps respectively in the future. Such a high bandwidth, however, is realized only in burst access along a limited, specific row direction in a memory space. That is, a speed in a so-called random access operation in which a row address is changed can be attained only on almost the same order as a conventional asynchronous DRAM.
A hierarchical structure of a memory has been adopted as a general measure to cope with this situation in a computer system which adopts a DRAM as the main memory. In a concrete manner, the measure is that a cache memory which is constructed from an SDRAM which can realize a high speed access as compared with a DRAM is interposed between a MPU and the DRAM and data of part of the DRAM is cached in the SRAM. In this case, a memory access from the MPU is performed on the high speed cache memory, and only when an access instruction enters an address space which is not cached in the cache memory, that is, when a cache miss occurs, an access is performed on the DRAM. A great improvement of a computer performance has been realized by adopting this measure even when operating speeds of the MPU and the DRAM are different from each other.
When a cache miss has occurs, however, read-out from the DRAM comes to be required and especially when a different row address in the same block in the DRAM memory space is accessed, there arises the maximal wait time for the MPU. This problem will be described with reference to FIG. 14 below.
FIG. 14 shows an example of a read operation timing for an SDRAM. When a cache miss occurs in the above described computer system which adopts a hierarchical structure of memory and a necessity of access to an SDRAM as a main memory arises, a [precharge command (Precharge)] is issued to perform precharge to an address which is now activated from the system side at time t1. Subsequently, an [activate command (Active)] is issued from the MPU after a predetermined time elapsed and a bank corresponding to a necessary memory space is activated. A [read command (Read)] is issued after another specific time elapsed. Data of a specific burst length is read out from the SDRAM in synchronism with a clock pulse at a time t2 when a specific time elapsed after the issuance of the read command. As shown here, the maximal bandwidth when a read operation is successively performed synchronously with a clock pulse is very high, whereas an effective bandwidth for random access in a cache miss is greatly decreased. That is, it is found that a portion of the time period between the time t1 and the t2 when no data is read out, in other word a wait time as viewed from the MPU side, is long.
In a concrete manner, in the case of the specifications of an SDRAM shown in FIG. 14, the maximal bandwidth in a random access cycle is of the order of 36% of that in a burst cycle at most. There will arise a high possibility for this to be a bottle neck in improvement on a computer performance hereinafter and therefore, a demand for a high performance DRAM has been increasing in which a high access time and a high speed cycle time are realized. Especially, in a multi-MPU system to which a current high-performance server machine is central, high importance is attached to not only high-speed burst transfer but high speed random access. Besides, in a consumer multi-media system in which real time reproduction of a dynamic image is the main object in the future, as well, a DRAM in which a high-speed random access is enabled in a similar way is considered to be a requirement.
With such demands in the backgrounds, an Enhanced SDRAM (ESDRAM) which has been announced from Enhanced Memory Systems Inc., as shown in FIG. 15, a Virtual Channel Memory (VCM) which has been announced from NEC Corp., as shown in FIG. 16, and the like have been proposed.
As described above, a DRAM, in which a high speed data cycle has been realized; represented by an SDRAM, an RDRAM and the like, suffers a long wait time when an access hit miss to require random access occurs, which is a problem to be a bottle neck in performance improvement of a system.
In the methods of FIGS. 15, 16 in each of which a large capacity cache memory is provided in order to realize a high speed access time and a high speed cycle time, the overhead for a chip size is high, which in turn causes a problem that realization of the low cost is harder to achieve.

Semiconductor memory capable of successively accessing cell array blocks with a plurality of operation modes having different cycle times


A conveyor specialized to convey people, and more particularly a conveyor which may serve as a conventional staircase, comprises treads that can individually raise and lower by the amount of the tread rise. To ascend, a user stands on the lowest level, and the tread lifts to match the height of the next tread. The user steps forward to the next tread. That tread likewise lifts to match the height of the next tread, and so on. In this way the user is able to ascend the height of the staircase without having to step up. A corresponding process permits descending the height of the staircase without having to step down. The conveyor can work even if the staircase winds or curves or goes around corners. Optionally a platform is caused to move laterally from each step to the next, so that the user need not even step forward during the process.

The invention relates to a conveyor specialized to convey people, and relates more particularly to a conveyor which may serve as a conventional staircase.
Before discussing the invention in detail it may be helpful to define certain terms.
Turning first to FIG. 1, what may be seen is a staircase 48, defined as a flight of stairs with its supporting framing and balustrade 41. Balusters 40 are shown, which are closely spaced vertical supports for railing 43. The railing 43 with supporting balusters 40 are referred to collectively as a balustrade 41. A fitting is a general term for a short transition piece in a handrail where there is a quick change in the direction of the handrail. A gooseneck 42 is a specific type of fitting designed to transition a stair handrail 43 to a horizontal guardrail 49.
It will be appreciated that balustrades are used not only on staircases but also on balconies. Thus a guardrail may be defined which is the top member of a balustrade system designed to keep people from falling off of an open balcony or staircase.
It will also be appreciated that some staircases are not "open," that is, some staircases have a wall to one side or both. On a side that is not "open" there is usually provided a handrail, defined as a long narrow band of wood or metal following the slope of a staircase placed at a height where a person can hold it for stability while climbing the staircase. It will be appreciate that sometimes a handrail may also act as a guardrail.
Turning to FIG. 2, treads 45 may be seen, each of which is defined as the upper surface of a step in a stair. The staircase may include risers 44, each of which is a vertical board spanning the space between treads on a staircase. Not all staircases have risers.
For a particular staircase there is a tread rise 46 defined as the vertical measurement from the top of one tread to the top of the next tread in line. Likewise there is a tread run 47 defined as the horizontal distance measured from the front of one tread to the front of the next tread above or below it. The slope of a staircase is defined as the measure of the angle formed by the relationship of rise to run on a staircase. The vast majority of staircases are designed so that the tread run is constant across all of the stairs of the staircase, and so that the tread rise is constant across all of the stairs of the staircase.
It will be appreciated that in some staircases, each tread 55 has a "nose" 51 as shown in FIG. 4. With such treads the tread run 47 is defined as shown, measured from the front of one tread to the front of the next tread above or below it.
Some staircases are built with one or more "stair jacks" or "stringers" 50 (FIG. 3) to which treads and risers are attached.
skilled in the art are also familiar with such terms as a "curved staircase," defined as a staircase which changes direction using a circular pattern with an inside radius less than twice the width of the individual treads; a "spiral staircase," defined as a staircase whose treads radiate from one central supporting post or newel; and a "winding staircase," defined as any staircase which changes direction while walking on individual treads which are tapered along their run. A "newel" or "newel post" can be a post giving additional structural support to a balustrade, or can be the central supporting post of a spiral staircase.
Much attention has been paid in recent years to the problem that some people find it difficult to ascend and descend staircases. Where a building (such as a residence or a commercial building) is being constructed, it is a straightforward matter to plan ahead and to provide escalators or elevators. An escalator is an endless loop of stairs which move upward or downward, with stairs returning to the other end of the escalator in a passageway beneath the staircase. An elevator, of course, requires an elevator shaft. An escalator requires setting aside a substantial volume for its return passageway, extending for some distance below the staircase. The escalator takes up a greater width than the width of the treads. Despite these requirements it is usually a straightforward matter, in the design of new construction, to provide any needed elevator shafts and any needed volumes for escalator return passageways and any needed widths.
It often turns out, however, that the need to accommodate a person who finds it difficult to ascend and descend staircases is perceived only after a building has been built. With such a building it is sometimes impossible, or at least prohibitively expensive, to add an elevator or escalator. In the case of a proposed elevator, it often develops that there is no suitable location for the placement of an elevator shaft. In the case of a proposed escalator which might replace a staircase, it often develops that there is no place to put the return passageway and that the width of an escalator is too great to fit in the width of the stairway that is to be replaced.
In a rented or leased space such as a residential apartment, or in a multitenant setting such as a cooperative or condominium apartment, there is a further difficulty in that even if cost is no object, and even if a location for an elevator or escalator can be found, it may be impossible to obtain permission from the landlord or condominium association to carry out the structural modifications that are required for installation of the elevator or escalator.
Faced with these concerns, the person desiring to accommodate (in an existing building) a person who finds it difficult to ascend and descend staircases often has only a few possible approaches, none of which is fully satisfactory. A typical approach is the installation of a chair and track mechanism. A track (or a set of tracks) is installed along one side of the stairway, and a mechanized chair is set up so that it may ascend and descend the track.
The tracked chair has numerous drawbacks. First, it takes away some of the otherwise usable width of the staircase. Even if every effort is made to minimize the lost width (e.g. if the chair seat can fold upwards for storage) the staircase will lose at least an inch or two of width.
Second, the track needs to be lubricated and the lubricated track is necessarily open (to some extent) so that there is the danger that clothing will be stained after coming into contact with the lubricant.
Third, it will often develop that if a person seeks to use the chair at one end (e.g. the top or bottom) of the staircase, this will happen at a time when the chair is at the other end of the staircase. This means that there must be a "call button" to call the chair to the would-be user, and the would-be user is forced to wait until the chair arrives.
Fourth, the chair track system may interfere with use of the hand rail on the side of the staircase where the track system is installed.
Fifth, not all staircases are well suited to chair track systems. A spiral or curved or winding staircase may rule out a track system due to the curves or the winding. Some two-part staircases go straight to a landing, and then proceed upwards at a different angle such as a right angle; such staircases sometimes rule out a chair track system.
Even a straight staircase may be unsuitable for a chair track system. For example if the staircase has balustrades and guard rails on both sides (i.e. neither side is a wall), it may turn out that there is insufficient structural strength in the balustrade to support the chair track system. Even if one side of the staircase has a wall, it may develop that the wall is unsuitable to support the chair track system, due to lack of sufficient structural strength or lack of suitable points of attachment.
It will also be appreciated that a chair track system may be used by at most one person at a time. This is a problem if one person wishes to ascend at the same time another person wishes to descend. It is also a problem if one person wishes to ascend a few moments after another person has already started to ascend. Finally, it is a problem if, say, two persons wish to ascend at the same time, since the chair does not have two seats.
Finally, and perhaps most importantly for many persons, a chair track system may be psychologically or emotionally or aesthetically undesirable. The chair track system is an extraordinarily prominent signal, incapable of being overlooked, that someone has difficulty ascending and descending stairs. This very signal may be uncomfortable for the persons residing in a home where it is proposed to install such a system. Many persons will find a chair track system to be aesthetically displeasing and may try to postpone or avoid its installation for that reason as well.
For all these reasons, it will be readily appreciated that there has been and is a long-felt need for a mechanism which would simultaneously fulfill several seemingly incompatible aims—a mechanism that is well-suited to helping people get from one level of a building to another, that is readily installed even in existing buildings, that can accommodate not only straight staircases but staircases which turn or go around corners, that is likely to be approved by a landlord or condominium association, that does not require structural modifications to the building, that does not take up otherwise usable width of a staircase, that will not make a person wait while it traverses the length of a staircase, and that is not visually intrusive.


A fusion protein having a non-immunoglobulin polypeptide having a cysteine residue proximal to the C terminal thereof, and an immunoglobulin component with a mutated hinge region is provided. The mutation comprises a point mutated site corresponding in position to the position in a native hinge region of the cysteine residue located nearest the cysteine residue of the non-Ig component. The distance from the cysteine residue of the non-immunoglobulin polypeptide and any remaining cysteine residues of the mutated hinge region is sufficient to prevent the formation of a disulphide bond therebetween.

Recombinant human proteins corresponding to their natural amino acid sequences have been used for the treatment and diagnosis of a broad range of human diseases since the 1980s. However, most recombinant human proteins do not survive long enough in vivo and are rapidly cleared from circulation. For example, proteins with a molecular mass less than 20 kDa have been reported to be filtered at the level of renal tubules, often leading to a dose-dependent nephrotoxicity. The short in vivo half-life of these proteins compromises their natural biological functions, requiring higher doses or more frequent administration, which in turn impairs patient compliance and increases the burden on health care providers. These clinical demands merit the search and development of therapeutic proteins with longer circulation half-life.
In addition to the direct mutations of individual protein structure for achieving longer half-life (e.g. ARANESP™ by Amgen and TNKnase by Genentech), two systemic approaches have been used for the creation of therapeutic proteins with longer half-life. One is "PEGylation", which refers to chemical cross-linking of polyethylene glycol (PEG) compounds to target proteins. PEG-bound proteins have larger molecular sizes and are more slowly cleared from the circulation. PEGylation has been clinically demonstrated and recognized by the biotech industry as a standard method of extending the half-life of various target proteins. A shortcoming of PEGylation is the significant impairment of the biological activity of target proteins. The altered structure of PEGylated proteins also risks generating an immunogenic response in the human body.
Another systemic approach is the genetic fusion of target therapeutic protein(s) with another human carrier protein to stabilize the target protein in circulation in the form of a fusion protein complex. Two ideal human carrier protein candidates for fusion with therapeutic proteins are human immunoglobulin and albumin. Both immunoglobulin and albumin are very stable and abundant in blood. Fusion proteins comprising a therapeutic protein and either immunoglobulin or albumin would theoretically retain the biological activity of the therapeutic protein, be more stable in circulation than the therapeutic protein alone, and be completely homologous to natural human proteins, minimizing the risk of immunogenic responses [1,2].
One practical strategy with this approach is to genetically fuse a therapeutic protein with an Fc fragment of a human immunoglobulin [1, 3, 4]. Modern bioengineering technology has successfully created fusion proteins consisting of a therapeutic protein, such as cytokines and soluble receptors, and an Fc fragment of immunoglobulin G (IgG) [5-26]. For example, IL-10, an anti-inflammatory and anti-rejection agent, has been fused to the N-terminal of murine Fc.gamma.2a to increase IL-10's short circulating half-life [9]. In another example, the N-terminal of human IL-2 has been fused to the Fc portion of human IgG 1 or IgG 3 to overcome the short half life of IL-2 and its systemic toxicity [26]. Two fusion proteins comprising an Fc fragment have been successfully developed as biomedicines and approved by FDA for the treatment of rheumatoid arthritis and chronic plaque psoriasis [27, 28, 29].
Human IgG is composed of four polypeptides (two identical copies of light chain and heavy chain) covalently linked by disulfide bonds. The proteolysis of IgG by papain generates two Fab fragments and one Fc fragment. The Fc fragment consists of two polypeptides linked by disulfide bonds. Each polypeptide, from the N-terminal to C-terminal, is composed of a hinge region, a CH2 domain and a CH3 domain. The structure of the Fc fragment is nearly identical across all subtypes of human immunoglobulin. IgG is one of the most abundant proteins in the human blood and makes up 70 to 75% of the total immunoglobulin in human serum. The half-life of IgG in circulation is the longest among all five types of immunoglobulin and may reach 21 days.
Disulfide bonds formed between thiol groups of cysteine residues play an important role in the folding and stability of proteins, usually when proteins are secreted to an extracellular medium. The disulfide bond stabilizes the folded form of a protein in several ways. First, it holds two portions of the protein together, biasing the protein towards the folded state. Second, the disulfide bond may form the nucleus of a hydrophobic core of the folded protein, i.e., local hydrophobic residues may condense around the disulfide bond and onto each other through hydrophobic interactions. Third, and related to the first and second points, by linking two segments of the protein chain and increasing the effective local concentration of protein residues, the effective local concentration of water molecules is lowered. Since water molecules attack amide-amide hydrogen bonds and break up secondary structures, disulfide bonds stabilize secondary structure in their vicinity. For example, researchers have identified several pairs of peptides that are unstructured in isolation, but adopt stable secondary and tertiary structure upon forming a disulfide bond between them. The native form of a protein is usually a single disulfide species, although some proteins may cycle between a few disulfide states as part of their function. In proteins with more than two cysteines, non-native disulfide species, which are almost always unfolded, may be formed.
A flexible junction region of the fusion protein which allows the two ends of the molecule to move independently plays a very important role in retaining each of the two moieties' functions separate and efficient. Therefore, the junction region should act as a linker which combines the two parts together, and as a spacer which allows each of the two parts to form its own biological structure and not interfere with the other part. Furthermore, in order to avoid the induction of immunogenicity, the junction region should be native to the human body and simple in structure [5, 25].
The primary structure of the hinge region of immunoglobulin includes three cysteines, such as cys223, cys229 and cys232 in the case of the human IgG 1 structure used by the present inventors. While the cys229 and cys232 form two interchain disulfide bonds by binding between counterparts of the two chains, the cys223 remains free. Therefore, it is highly possible that this free cysteine may bind with another intrachain or interchain cysteine, to form a non-native disulfide bond in the protein maturation process upon secretion from host cells or during subsequent purification. This non-native disulfide bond may not only alter the structure and conformation of the therapeutic protein, but may also interfere with the biological activity of the therapeutic protein or induce harmful immunogenicity when the fusion protein is administrated into the human body.
Many therapeutic proteins such as erythropoietin (EPO) and granulocyte macrophage colony-stimulating factor (GM-CSF) have a cysteine near their C-terminal. The role of this cysteine in maintaining proper structure and function has yet to be well-defined. The cysteine proximal to the C-terminal may be essential for maintaining proper structure, facilitating correct folding or retaining normal biological activity. The inventors hypothesize that if proteins with a cysteine near its C-terminal are fused to the natural sequence of the hinge region of a Fc fragment, the very limited space between the last cysteine of the C-terminal of the fused protein and the first cysteine of the N-terminal of the Fc fragment (cys223) may lead to the formation of an unexpected disulfide bond between these two cysteines. The formation of the unexpected disulfide bond may alter the structure and/or the folding of the fused protein component as well as alter the flexibility of the hinge region. As a result, normal functions of the fused therapeutic protein in the fusion protein complex may be impaired.
Even if the target therapeutic protein does not contain a cysteine near its C-terminal, another cysteine in its structure may, after three dimensional folding, become sufficiently close to the free cysteine (e.g. cys223) of the hinge region to form a non-natural disulfide bond that may alter the structure and biological activity of the fused target protein. The inventors' hypothesis may partially explain why there has yet to be any clinically-proven success in attempts to create functional fusion proteins with widely-used growth factors such as EPO, G-CSF and GM-CSF, etc.
Previous reports have used various methods to create fusion proteins between a therapeutic protein and an Fc fragment/immunoglobulin molecule. In most of these reports, researchers changed amino acid sequences of the target protein, added a linker peptide between the C-terminal of the target protein and the N-terminal of the hinge region of Fc fragment, or truncated the hinge region of the Fc fragment of the hinge region (resulting in the removal of the free cysteine (e.g. cys223)).
In U.S. Pat. No. 5,908,626, a fusion protein of IFN β with a human immunoglobulin Fc fragment is described which was linked by a synthetic oligopeptide (GGS)2(GGGS)2 [6]. The inventors in that patent believe this linker can "reduce the possibility of generating a new immunogenic epitope (a neoantigen) at what would otherwise be the fusion point of the IFN β and the immunoglobulin Fc fragment". In U.S. Pat. Nos. 6,797,493, 6,900,292, 7,030,226, 7,226,759, and 7,232,668, the hinge region was replaced by a 16-amino acid peptide linker GS(GGGS)3GS [10, 12, 13, 20, 21]. In addition to the genetic approach, chemical manipulation has also been used to address the problem of non-native disulfide bonds. For example, the inventors in U.S. Pat. No. 6,808,902 developed a process for treating an IL-1ra-Fc fusion protein with a copper (II) halide in order to prevent or correct a non-native disulfide bond which caused misfolding of that fusion protein [12]. An Fc-EPO fusion protein (rather than the conventional EPO-Fc fusion) has shown poor pharmacokinetics and little EPO efficacy in mice; mutation of four amino acids of the EPO molecule is required to obtain a functional Fc-EPO fusion protein [30].
As mentioned above, the hinge region plays the role of the flexible junction region between the fused therapeutic protein and the Fc fragment (CH2 and CH3). Truncation or significant changes of the hinge region may have undesirable effects on ability of the hinge region to act as flexible junction. The addition of peptide linkers may not only impair the natural conformation of the fusion protein but also greatly increase the risk of immunogenicity by introducing a non-native structure.
The need exists for therapeutic protein/Fc fragment fusion proteins that have a prolonged half-life and/or enhanced activity without increasing the risk of an immunogenic response.

Fusion proteins having mutated immunoglobulin hinge region