A micromachine includes a switch having a supporting member provided on a substrate. The supporting member is adjacent to a gap between a signal line and the substrate and has a predetermined height with respect to the substrate. A flexible beam member projects from the supporting member generally parallel to the substrate and extends so that part of the flexible member faces the gap. A contact electrode on the beam member faces the gap. A lower electrode on the substrate faces part of the beam member. Part of the beam member is conductive to function as an upper electrode. The thermal expansion coefficients of the beam member are almost symmetric in the thickness direction perpendicular to the substrate surface, at least from the portion at which the beam member is connected to the supporting member to the portion facing the lower electrode.

The present invention relates to a micro machine switch and a method for manufacturing thereof and in particular to a micro machine switch which allows the on/off control of a wide range of signal frequency, that is, from DC (direct current) signal frequency to signal frequency of one or more giga Hertz and a method for manufacturing thereof.
In the following the prior art will be described taking the case of the invention described in xe2x80x9cMicro Electromechanical Switchxe2x80x9d, by Yun Jason Yao, ROCKWELL INTERNATIONAL CORPORATION (Japanese Patent Laid-Open No. Hei9-17300).
FIGS. 16(a) and 16(b) are a plan view of the micro machine switch disclosed in Japanese Patent Laid-Open Hei9-17300 and a cross-sectional view of the same taken along the line D-Dxe2x80x2, respectively. As shown in the same figures, an anchor structure 52 comprising thermosetting polyimide, a lower electrode 53 composed of gold and signal lines 54 comprising gold are provided on a substrate 51 comprising gallium arsenide.
And on the anchor structure 52 provided is a cantilever arm 55 consisting of silicon oxide, which extends to the signal lines 54 across the lower electrode 53 and faces the same with a space left between them.
An upper electrode 56 comprising aluminium is formed on the top of the cantilever arm 55 in such a position so as to face the anchor structure 52 and the lower electrode 53. And a contact electrode 57 comprising gold is provided on the bottom of the cantilever arm 55 in such a position so as to face the signal line 54.
In the micro machine switch having such construction, when applying a voltage of 30 V between the upper electrode 56 and the lower electrode 53, the force of attraction is applied to the upper electrode 56 in the direction of the substrate (downward in the direction shown by the arrow 58 by the electrostatic force). Therefore, the cantilever arm 55 is strained toward the substrate side; as a result, the contact electrode 57 comes in contact with both ends of the signal lines 54.
In the normal state, a space is provided between the contact electrode 57 and the signal lines 54, as shown in FIG. 16(b); accordingly, the two signal lines 54 are separated from each other. Thus, in state where no voltage is applied to the lower electrode 53, no current flows through the signal lines 54.
On the other hand, in state where voltage is applied to the lower electrode 53 and the contact electrode 57 is in contact with the signal lines 54, the two signal lines 54 short-circuit, which allows current to flow between them. Thus, the application of voltage to the lower electrode 53 allows the on/off control of the electric current or signals passing through the signal lines 54.
However, in order to reduce the switch loss particularly when using the switch for the signals in the microwave range, it is important that the upper electrode 56 and the contact electrode 57 are well insulated from each other. In other words, if the upper electrode 56 and the contact electrode 57 short-circuit, signals (including DC) flowing through the signal lines 54 flow out even to the upper electrode 56.
Even if the upper electrode 56 and the contact electrode 57 do not short-circuit, in state where electrostatic capacity is significantly large, alternate signals flowing through the signal lines 54 also flow out to the upper electrode 56 and leak outside.
As described above, when the upper electrode 56 and the contact electrode 57 are not well insulated, the leak of signals becomes large, and switching characteristics deteriorate. From this viewpoint, the prior art described above uses an insulating material (silicon oxide) as the material constituting the cantilever arm 55.
The micro machine switch of the prior art described above has the following problems.
The cantilever arm 55 is contact with the upper electrode 56 and the anchor structure. 52, both of which differ from the cantilever arm 55 in the material, over a wide range. Further, the cantilever arm 55 is designed to have a mechanically flexible construction so as to control the driving voltage of the switch and to move only by applying micro voltage.
As described above, since the upper electrode 56, the cantilever arm 55 and the anchor structure 52 are formed of different materials, their thermal expansion coefficients are also different, and particularly in the cantilever arm 55, warps are likely to be caused due to distortion.
For example, when comparing silicon dioxide, aluminium and polyimide, the thermal expansion coefficient of silicon dioxide is about 1/100 times as small as those of the other two. Therefore, the metal portion of the upper electrode 56 etc. expands with the changes in the processing temperature and the atmospheric temperature after the completion of a device, and thereby warps are easily caused in the cantilever arm 55.
The existence of such warps has a bad influence on switching characteristics regardless of their direction relative to the substrate 51. In cases where the cantilever arm 55 warps upward, even if the bottom side surface of the cantilever arm 55 comes in contact with the lower electrode 53 by the application of voltage, a state is likely to occur in which the contact electrode 57 does not come in contact with the signal lines 54. In that case, even if the contact electrode 57 comes in contact with the signal lines 54, the intensity of pressure applied to the contact portion is very small, and such a very light contact gives rise to a problem of increasing the contact resistance of the switch.
On the other hand, in cases where the cantilever arm 55 warps downward, although the contact electrode 57 surely comes in contact with the signal lines 54 due to application of a voltage, the entire contact electrode does not come in planar contact with the signal lines 54, and what is called single contact (both come in contact with each other only at one area) is very likely to occur. Thus, even in this case, there arises a problem of increasing the contact resistance of the switch.
As described above, in any case, a problem is created such that warps caused in the cantilever arm 55 increase the contact resistance, resulting in increasing the switch resistance when the switch is in the on state.
In fact, in the micro machine switch according to the prior art, the switch production process is performed at a low temperature of 250xc2x0 C. or lower, and thereby warps caused due to the processing temperature are controlled.
To be concrete, a silicon dioxide film for making up the cantilever arm 55 is formed by the plasma enhanced CVD (PECVD) process. A PECVD oxide film offers the advantage of being able to be formed at low temperatures, and keeping the processing temperature low is important when decreasing the influence of the big difference in thermal expansion coefficient from material to material.
On the other hand, it is well known that mechanical properties (distortion, rigidity, reliability, etc.) and electrical properties (dielectric constant, maximum breakdown voltage, etc.) of materials can be remarkably improved by the optimization of, particularly, temperature conditions.
However, in the micro machine switch according to the prior art as described above, since the processing temperature needs to be kept low, the temperature parameter cannot be made good use of for optimizing the materials. In this respect, the prior art can be said to be limited largely in material.
Generally, a cantilever arm has the advantage that the width of its arm can be decreased when increasing its thickness so as to keep the rigidity constant. Thus, it has another advantage that the dimensions of the entire switch can be decreased, therefore, multiple switches can be formed in a limited area.
However, in the micro machine switch according to the prior art, which utilizes silicon dioxide for the cantilever arm, it is limited largely in the thickness of the cantilever arm 55. In principle, the thickness of silicon dioxide film can be increased to 10 xcexcm or more by increasing the PECVD duration; however, increasing the growth duration means decreasing the processing rate of the PECVD system, which results in increasing costs and giving rise to various problems involving the maintenance of the system, for example, such that cleaning is often required since dust is likely to be caused.
Further, inside the thick film a large amount of distortion is caused, which gives rise to a problem of fracturing the substrate 51 during the deposition of silicon dioxide. For the reasons as above, the actual situation is such that the thickness of the cantilever arm is limited to about 2 xcexcm at most. Thus the micro machine switch according to the prior art is strictly limited in design dimensions of its construction.
In addition, the decrease in processing temperature as is performed in the prior art is effective to some extent in controlling warps caused during the manufacturing process, but not effective at all in controlling warps caused due to the variation in atmospheric temperature under which the micro machine is used. The problem of causing warps during the use of the micro machine is an inevitable consequence of using laminated films different in thermal expansion coefficient in the arm portion of the switch.
At the same time, the micro machine switch having the construction according to the prior art has the problems of mechanical strength and durability. When driving the switch, the highest stress is set up at the base of the cantilever arm 55 (at the portion where the cantilever arm 55 is connected to the anchor structure 52). Accordingly, in order to improve the mechanical strength and durability of the switch, it is necessary to optimize the structure of the base portion.
In the construction of the micro machine switch according to the prior art, the cantilever arm 55 and the anchor structure 52 are formed of different materials and placed perpendicularly to each other. And this construction is not suitable for relieving the stress given rise to at the base portion.
The present invention has been made so as to overcome the above problems, accordingly the object of the present invention is to provide a micro machine switch which can be mass-produced, is low-cost and is high-performance and a method for manufacturing thereof
In order to achieve the above object, one aspect of the micro machine switch according to the present invention relates to a micro machine switch for controlling the conduction/non-conduction between first and second signal lines which are provided on a substrate in such a manner as to leave a predetermined gap between their respective end portions. The micro machine switch as above includes: a supporting member provided on the above substrate in such a manner as to be adjacent to the above gap and to have a predetermined height with respect to the surface of the above substrate; a flexible beam member provided in such a manner as to project from the supporting member almost horizontally to the above substrate surface and to extend so far that its part faces the above gap; a contact electrode provided on the substrate side of the above beam member in such a position as to face the above gap, and a lower electrode provided on the above substrate in such a manner as to face part of the above beam member. Part of the above beam member, which ranges from the portion at which it is connected to the above supporting member to the portion facing the above lower electrode, is allowed to be conductive, and hence to function as an upper electrode. And the thermal expansion coefficients on the substrate side of the above beam member and on the opposite side of the same are allowed to be almost symmetric in the thickness direction perpendicular to the above substrate surface, at least in the region ranging from the portion at which it is connected to the above supporting member to the portion facing the above lower electrode.
In another aspect of the micro machine switch according to the present invention, the angle made between the substrate side surface of the above beam member and the surface of the above supporting member to which the above beam member is connected is an obtuse angle.
In another aspect of the micro machine switch according to the present invention, the above supporting member protrudes higher than the surface of the above beam member opposite to the substrate side surface of the same, at the portion both members are connected to each other.
In another aspect of the micro machine switch according to the present invention, the angle made between the beam member surface opposite to the substrate side surface of the same and the surface of the above supporting member protruding higher than the above beam member surface is an obtuse angle.
In another aspect of the micro machine switch according to the present invention, the angle made between the substrate side surface of the above beam member and the side surface of the above supporting member to which the above beam member is connected is an obtuse angle.
In another aspect of the micro machine switch according to the present invention, the above contact electrode is provided on the above substrate side of the above beam member via an insulating member.
Another aspect of the micro machine switch according to the present invention is characterized in that on the surface of the above beam member, which is opposite to the surface provided with the above contact electrode, a reinforcing member is provided in such a manner as to face the above contact electrode.
In another aspect of the micro machine switch according to the present invention, the above contact electrode is coated with an insulating material film capable of capacity connecting to the above first and second signal lines.
In another aspect of the micro machine switch according to the present invention, the above lower electrode is provided on the above substrate in such a position so as to be between the above supporting member and the above gap.
In another aspect of the micro machine switch according to the present invention, the above supporting member and at least part of the above beam member are formed of the same conductive material as an integral unit.
In another aspect of the micro machine switch according to the present invention, part of the above beam member, which ranges from the portion at which it is connected to the above supporting member at least to the portion facing the above lower electrode, is formed of a conductive member and on the tip portion of the conductive member an insulating member is provided which extends to the position facing the above gap, the above contact electrode being provided on the insulating member in such a manner as to face the above gap.
In another aspect of the micro machine switch according to the present invention, the above conductive member consists of a semiconductor material.
In another aspect of the micro machine switch according to the present invention, the above beam member consists of a semiconductor material and at least the region ranging from the portion at which the above contact electrode is provided to the portion facing the above lower electrode is insulated.
In another aspect of the micro machine switch according to the present invention, the above semiconductor material is a single crystal semiconductor.
In another aspect of the micro machine switch according to the present invention, the above semiconductor material is an amorphous semiconductor or polycrystalline semiconductor.
In another aspect of the micro machine switch according to the present invention, the above substrate is a glass substrate or a ceramic substrate.
In another aspect of the micro machine switch according to the present invention, the above substrate is a gallium arsenide substrate.
Another aspect of the micro machine switch according to the present invention is used in a phased array antenna system.
One aspect of the method for manufacturing a micro machine switch according to the present invention relates to a method for manufacturing a micro machine switch for controlling the conduction/non-conduction between first and second signal lines which are provided on a substrate in such a manner as to leave a predetermined gap between their respective end portions. The method includes: a step of forming a lower electrode on the above substrate; and a step of bonding a member, which consists of a supporting member having a predetermined height, a flexible beam member provided on the supporting member and a contact electrode provided on the beam member, to the above substrate while allowing the above contact electrode to face the above gap and to be spaced apart from the first and second signal lines. The above beam member is formed in such a manner that its part, which ranges from the portion at which it is connected to the above supporting member to the portion facing the above lower electrode, is allowed to be conductive and hence to function as an upper electrode and that the thermal expansion coefficients of its both sides, at least the region ranging from the portion at which it is connected to the above supporting member to near the portion facing the above lower electrode, are allowed to be almost symmetric in the thickness direction perpendicular to the above substrate surface.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the angle between the substrate side surface of the above beam member and the surface of the above supporting member to which the above beam member is connected is made an obtuse angle.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above supporting member is formed in such a manner as to protrude higher than the surface of the above beam member opposite to the substrate side surface of the same, at the portion both members are connected o each other.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the angle between the beam member surface opposite to the substrate side surface of the same and the surface of the above supporting member protruding higher than the above beam member surface is made an obtuse angle.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the angle between the substrate side surface of the above beam member and the side surface of the above supporting member to which the above beam member is connected is made an obtuse angle.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above contact electrode is provided on the above substrate side of the above beam member via an insulating member.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, on the surface of the above beam member opposite to the surface of the same which is provided with the above contact electrode, a reinforcing member is provided in such a manner as to face the above contact electrode.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above contact electrode is coated with an insulating material film capable of capacity connecting to the above first and second signal lines.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above lower electrode is provided on the above substrate in such a position so as to be between the above supporting member and the above gap.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above supporting member and at least part of the above beam member are formed of the same conductive material as an integral unit.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, part of the above beam member, from the portion at which it is connected to the above supporting member at least to the portion facing the above lower electrode, is formed of a conductive member and on the tip portion of the conductive member an insulating member is provided which extends to the position facing the above gap, the above contact electrode being provided on the insulating member in such a manner as to face the above gap.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above conductive member is formed of a semiconductor material.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above beam member is formed of a semiconductor material and at least the region ranging from the portion at which the above contact electrode is provided to the portion facing the above lower electrode is insulated.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, a single crystal semiconductor is used as the above semiconductor material.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, an amorphous semiconductor or polycrystalline semiconductor is used as the above semiconductor material.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, a glass substrate or a ceramic substrate is used as the above substrate.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, a gallium arsenide substrate is used as the above substrate.
In another aspect of the method for manufacturing a micro machine switch according to the present invention, the above micro machine switch is used in a phased array antenna system.
In the micro machine switch of the present invention constructed as described above, thermal expansion coefficients of the both side of the beam member material are almost symmetric in the thickness direction perpendicular to the substrate surface. Accordingly, warps caused due to the distortion occurring between different materials, as seen in the micro machine switch of the prior art, are considerably relieved. The simplest method for allowing the thermal expansion coefficients to be symmetric in the thickness direction is to form the beam member of only one material. It goes without saying that the beam member can also be formed to have a laminated structure which is symmetric in the vertical direction.
In order to suppress warps caused in the beam member, it is effective to allow the thermal expansion coefficients to be symmetric as described above particularly in the neighborhood of the portion at which the beam member is connected to the supporting member, more concretely, in the region ranging from the portion at which the beam member is connected to the supporting member at least to the portion facing the lower electrode. Conversely, in the neighborhood of the tip portion of the beam member, even if the thermal expansion coefficients are not symmetric in the thickness direction, warps are not very large.
When making measurements for the experimentally manufactured switches, it was found that the variation in contact resistance created due to single contact etc. was narrowed and thereby a large amount of switches uniform in characteristics could be manufactured.
It was also found that the change in switching operation was considerably small even if the ambient temperature of the switch changed.
Further, the micro machine switch according to the construction of the present invention has been improved in mechanical strength, durability and operational speed, compared with that of the prior art. For example, allowing the angle between the beam member and the supporting member on the substrate side to be an obtuse angle makes it possible to prevent the base of the beam member from being fractured by a stress concentration. Allowing the supporting member to protrude higher than the beam member makes it possible to give the structure in the neighborhood of the base of the beam member a shape which is almost symmetric in the vertical direction. This allows the thermal expansion coefficient distribution in the neighborhood of the base of the beam member, including the supporting member, to be symmetric, which is effective in preventing warps caused in the beam member.
The upward protrusion of the supporting member effectively improves the operational speed of the switch. Specifically, it is effective in increasing the speed of the switch""s returning motion, from the on state (the state in which the switch is dropped) to the off state (the state in which the switch is raised). This is because stresses set up at the base of the beam member become larger when the supporting member protrudes higher than the beam member. When turning on/off the switch, since the operation is very rapid, a phenomenon can sometimes occur that the beam member vibrates up and down (referred to as bound chattering). In order to stop this bound chattering promptly, it is necessary to let the supporting member absorb the kinetic energy of the beam member by setting up a moderate stress at the base of the beam member, and for this purpose, the structure is effective in which the supporting member protrudes higher than the beam member.
In the micro machine switch as above, the beam member is weakest of all the members in terms of the mechanical strength. Accordingly, the micro machine switch preferably has a structure which allows preventing the beam member from fracturing due to the contact with the substrate etc. when mounting the same on the substrate in its manufacturing process. Thus, if the micro machine switch is constructed in such a manner that the supporting member protrudes higher than the beam member, the contact accidents of the beam member can be suppressed, and thereby the likelihood of fracturing the switch can be reduced.
And when protruding the supporting member higher than the beam member, preferably the angle between the surface of the beam member and that of the supporting member on the opposite side to the substrate is allowed to be an obtuse angle, because doing so allows preventing the base of the beam member from fracturing due to a stress concentration. When the angles between the beam member and the supporting member are allowed to be obtuse angles both on the substrate side and on the opposite side to the substrate, both of the angles are preferably in the range of 100xc2x0 to 170xc2x0, more preferably 110xc2x0 to 150xc2x0 This allows the effect of decreasing a stress concentration as described above and the effect of setting up an appropriate stress to improve the operational speed to be compatible with each other.
Forming the supporting member and part of the beam member including at least the base portion of the same material allows reducing of the warps caused between the two members, suppressing of a stress concentration on one point and improving the strength of the micro machine switch, which results in improving the durability of the micro machine switch. And if the supporting member, the beam member and the upper electrode are all formed of the same material, the manufacturing process can be simplified.
Further, since the high-temperature process can be utilized, the number of alternatives for the materials constituting the beam member etc. is increased and various types conductors and semiconductors can be utilized, thus the degree of freedom of selecting material is increased. The insulating film formed at high temperatures in particular is excellent in resistance to pressure, this may contribute to electrical characteristics of devices.
Further, since the degree of freedom of the beam member (cantilever arm) is increased in the thickness direction, the width of the arm can be decreased, and thereby the size of the switch can also be decreased.
The beam member constituting the micro machine switch of the present invention is conductive at least for the part ranging from the portion at which it is connected to the supporting member to the position facing the lower electrode, and the xe2x80x9cconductivexe2x80x9d materials herein used are not limited to conductors such as metals. The point is whether or not voltage can be applied through the supporting member to such a position of the beam member so as to face the lower electrode, and current hardly flow this portion. Accordingly, as the materials for use in the part of the beam member ranging from the portion at which it is connected to the supporting member to such a position so as to face the lower electrode, a wide variety of materials such as metals-and semiconductors can be adopted. And when using semiconductor materials, the presence and the concentration of impurities added can be changed widely.
Because of the excellent effects as described above, the micro machine switch of the present invention can be applied not only to a simple switch which uses only a single micro machine switch, but also to a phased array antenna system which requires micro machine switches of order of tens of thousands to be integrated on a large area of substrate.

Micromachine switch and its production method


An aircraft data transmission system used with an aircraft having a data acquisition unit. The system includes a communications unit located in the aircraft and in communication with the data acquisition unit. The system also includes a cellular infrastructure in communication with the data communications unit after the aircraft has landed. The system further includes a data reception unit in communication with the cellular infrastructure.

1. Field of the Invention
The present invention is directed generally to an aircraft flight data acquisition and transmission system and, more particularly, to an on-board cellular data transmission system.
2. Description of the Background
It is common for aircraft to generate records of data relating to flight and performance parameters for each flight of the aircraft. The data typically relate to parameters such as air speed, altitude, vertical acceleration, heading, time, etc. The data are utilized in the event of an accident or a near-accident and to assist in maintenance of the aircraft by detecting faulty components or gradual deterioration of a system or component, to assist in reviewing crew performance, and to assist in logistical planning activities such as scheduling and routing.
Aircraft data are typically gathered by a digital flight data acquisition unit (DFDAU). The DFDAU typically stores the data on magnetic or magnetic-optical media. When the aircraft lands, ground personnel board the aircraft, remove the media, and mail the media to a flight operations center (FOC). The manual removal and posting of the data adds a significant labor cost, yields less than desirable data delivery reliability, and results in a significant time delay before the data are useful for analysis.
It is known to use radio frequency (RF) transmissions to transmit data relating to an aircraft. Such teachings, however, require substantial investments to construct the RF transmission systems required for such a system to work. Furthermore, it is very expensive to create redundancy in such a system.
It is also known to transmit data relating to an aircraft via a telephone system located in a terminal. Such a system, however, requires that the aircraft be docked at the gate before transmission begins, thereby resulting in a substantial delay in the transmission. Furthermore, such a system requires an added step of transmitting the data from the aircraft to the terminal telephone system, increasing the cost of installing, operating, and maintaining such a system.
Thus, there is a need for an aircraft data transmission system that automatically transfers flight data from an aircraft to a flight operations center with little or no human involvement and which relies on a reliable wireless delivery system.

Aircraft flight data acquisition and transmission system


A playing structure includes a plurality of playing structure modules connectable together to form an array having a generally continuous, visually fluid, three-dimensional playing surface. Each playing structure module has a reversible top to allow the topography of the playing surface to be changed. The top of each playing structure module has a different three-dimensional topography on either side thereof. Each playing structure module may have a different or the same top. The playing surfaces have a coloured landscape painted thereon to depict lakes, countrysides, roadways etc. and the like. The topography of the playing surfaces and the painted landscapes are designed so that the certain symmetries exist. In particular, when a plurality of playing structure modules are assembled to form an array and the tops of the playing structure modules are arranged to provide a playing surface having a continuous, visually fluid landscape, any one of or all of the tops can be reversed along a diagonal and the landscape of the resulting playing surface will still be continuous and visually fluid. This of course increases the number of different playing surfaces which can be created with the playing structure modules.

Many children's toys are available which allow a child to build structures such as houses and the like and in effect create cities. Of the toys of this nature, one of the most common are building blocks commonly referred to as Lego.RTM.. These building blocks are best assembled on a playing surface where the child can move miniature vehicles, people and animals and rearrange the built structures.
Unfortunately children have very few supportive and convenient places to play with the above type of toys. In most households, the playing surface referred to above is constituted by a free space on a hardwood floor, an unoccupied table top or desk surface and in some instances the top of a bed. Each of these types of playing surfaces when used for play is limited and is inconvenient in some way. Moreover, these playing surfaces do not encourage or suggest directions for a child's fantasy. It is solely up to the child's imagination to transform the otherwise plain surface into one which has a varying topography and landscape.
Another disadvantage associated with these playing surfaces is that when the child is finished playing, the child's toys remain in the way.
To alleviate some of the above-mentioned problems, playing surfaces having printed presentations on which toys are to be moved have been considered. For example, U.S. Pat. No. 3,206,887 to Eyler et al discloses a children's toy in the form of a pad having a number of pages. Printed on one side of most of the pages in the pad are roadways while on the other pages are representations of vehicles which can be punched out from the pages. The pages with roadways printed thereon also have different locations of interest drawn on them and a legend indicating the drawn area of interest. The roadways are drawn on the sheets in a manner so that the roadway is continuous when two sheets are properly oriented and placed side by side. Although this provides a playing surface with roadways, the surface itself is relatively plain and does not resemble real terrain. In addition, the planar nature of the sheets requires an underlying support and therefore, this toy still suffers from many of the disadvantages discussed previously.
It is therefore an object of the present invention to provide a novel playing structure having a three-dimensional playing surface which resembles real terrain more closely than prior art playing surfaces and which is changeable to allow different playing surfaces to be created.

Playing structure and storage system and modules therefor


The present invention describes a light mixing waveguide including a transparent slab waveguide having a reflectorized edge, a pair of opposing side edges adjacent to the reflectorized edge, a light transfer edge opposite the reflectorized edge, and a plurality of cavities formed inside the slab waveguide, wherein at least one of the side edges is configured to receive light from one or more light sources so that the received light is totally-internally reflected from top and bottom surfaces of the transparent slab waveguide. Interaction of the received light, the cavities, and the reflectorized edge mixes the received light prior to the light passing through the light transfer edge and into a target optical system.

Various flat panel display systems have been developed over the last several decades. Among them is the Time Multiplexed Optical Shutter disclosed in Selbrede U.S. Pat. No. 5,319,491 (which is incorporated in its entirety herein) and such variations as have been subsequently filed in commonly owned U.S. Pat. Nos. 7,042,618, 7,057,790, 7,218,437, 7,486,854 and U.S. Patent Publication No. 2008/0075414. The fundamental premise of such devices is that light (usually monochromatic light) is edge-injected into a transparent rectangular slab waveguide such that total internal reflection (TIR) of the injected light obtains within the waveguide, which may be mirrored on one or more of the side surfaces to insure maximum transits for rays traveling within the waveguide. The principle of operation for any of the plurality of pixels distributed across the slab waveguide involves locally, selectively, and controllably frustrating the total internal reflection of light bound within the waveguide to emit light at that pixel location. In one pixel architecture, frustration of TIR light bound within the waveguide is achieved by propelling (i.e., moving) an optically-suitable material across a microscopic gap, such that the material is at or near contact with a surface of the slab waveguide in the active position, while in the inactive position the material is sufficiently displaced from the surface of the waveguide so that light and/or evanescent coupling across the gap is negligible. The optically-suitable material, herein referred to as an "active layer", being propelled (i.e., moved) can be an elastically deformable thin sheet (thin layer or film) of polymeric material (e.g., elastomer) with a refractive index selected to optimize the coupling of light during the contact/near-contact events. Switching the active layer between inactive and active positions can occur at very high speeds in order to permit the generation of adequate gray scale levels for multiple primary colored light (e.g., consecutive primary colored lights red-green-blue) at video frame rates in order to avoid excessive motional and color breakup artifacts while preserving smooth video generation. The flat panel display is thus comprised of a plurality of pixels, each pixel representing a discrete subsection of the display that can be individually and selectively controlled in respect to locally propelling the active layer bearing a suitable refractive index across a microscopic gap into contact or near contact with the slab waveguide. The propulsion can be achieved by the electromechanical and/or ponderomotive deformation of the thin sheet of polymeric material, said sheet being tethered at the periphery of the individual pixel geometry by standoffs that maintain the sheet in a suitable spaced-apart relation to the slab waveguide when the pixel is in the quiescent unactuated state. Application of an appropriate electrical potential across a first conductor disposed on or within the slab waveguide and a second conductor disposed on or within the active layer, causes the high-speed motion of the active layer toward the surface of the slab waveguide; actuation is deemed completed when the active layer can move no closer to the slab waveguide (either in itself, or due to physical contact with the waveguide). To facilitate light extraction, an array of micro-optical structures (of various possible geometries, such as frustums or pyramidal sections, etc.) may be optionally disposed on the waveguide-facing side of the active layer, such that pixel actuation entails contact or near-contact of these micro-optical structures with the waveguide, thus frustrating TIR light in such a way that re-direction of extracted light to the viewer is optimized. A more detailed description of micro-optical structures is disclosed in "Optical Microstructures for Light Extraction and Control" U.S. Pat. No. 7,486,854, which is incorporated herein by reference in its entirety.
Certain other display systems use similar (but not identical) principles of operation. Some utilize a backlight system where the pixels literally shutter light, usually by transverse lateral motion of an opaque MEMS-based shuttering element at each pixel parallel to the main surface (e.g., top surface) of the waveguide configured as a true backlight system proper, contra the TIR-based waveguide of Selbrede '491 which is not a true backlight given the TIR-bound condition of light traveling inside it. For a backlight system, light within the slab waveguide should not be maintained in a TIR-compliant state lest it be perpetually bound to the interior of the waveguide. Thus, the bottom surface of the waveguide can be made a scattering surface, or it can diverge from a parallel spaced-apart relation to the top surface of the waveguide, or both, to insure that light continually departs the top surface of the slab waveguide to illuminate the pixel shutter mechanisms arrayed at or above the top surface of the slab waveguide. The appeal of using a slab waveguide for transverse MEMS shutter-based systems is due to the ability to recycle unused light by configuring the waveguide-facing portions of the shutter mechanisms to be nominally reflective. Light not passing through an open shutter may then re-enter the waveguide and can be used elsewhere within the system.
In the case of devices based on Selbrede '491, in which the light sources are arrayed on one edge of the slab waveguide while the opposite end from said edge is mirrored (with either a metallic reflector disposed thereon or by imposition of a perfect dielectric mirror to gain even better reflectance), it has been determined that the luminous uniformity of the display can only be insured when the thickness of the slab waveguide is sufficiently thick. A minimum slab waveguide thickness, t, that can be utilized for the slab waveguide is a function of the length of the waveguide l, the critical angle of the waveguide θc (which is itself a function of the waveguide's refractive index), and the individual optical efficiency of a pixel on the display surface, denoted ∈. The mean free path of a given photon ensemble from origin at the light source to 99% depletion inside the waveguide is given the Greek symbol λ, which is not to be confused with the optical wavelength of that light in this context. By detuning the effective individual pixel efficiency ∈, and using the resulting average mean free path of a photon ensemble prior to 99% depletion, λ, uniformity has been demonstrated to be readily optimized when λ=3l or greater, thereby establishing a lower bound on slab thickness by the following equation:
  t  =            3      -                        (                                    log                                            (                0.01                )                                                    log                                            (                                  1                  -                  ɛ                                )                                              )                        l                    (                                    cos                                      (                              θ                c                            )                                                      log                                      (              0.01              )                                                log                                (                          1              -              ɛ                        )                              )
Applying this constraint to the slab waveguide thickness enables displays based on such waveguides to achieve in excess of 60% optical efficiency (ratio of light flux input to light flux output) while simultaneously insuring far less than 1 dB variation in luminosity across the entire display surface (typically under 0.2 dB variation).
While this constraint is of minimal consequence for many applications, it does present a step backward for applications where the industry trend has been toward thinner display subsystems year after year. Thus, for a cell phone, the thickness constraint might require the waveguide to be up to 2 millimeters thick or more to insure outstanding luminous uniformity, whereas the trend in cell phone display components is for the display to be under 1 mm in total thickness. In actual fact, a waveguide thickness of 0.7 mm is desirable, given that this is a standard thickness for LCD mother glass and TFT active matrix glass. However, so thin a waveguide, by violating the thickness t constraint outlined above, runs a serious risk of suffering from debilitating nonuniformities in brightness across the display surface. The symbol t shall hereafter be denominated the minimum slab waveguide thickness that corresponds to the minimum luminous uniformity threshold limit.
Recent co-pending filings have disclosed various apodization (compensation) means in orienting and configuring the illumination means at the edge(s) of the waveguide (e.g., a varying distribution of light sources along an edge of the waveguide) to resolve luminous nonuniformity. However, the periodicity of the pixels and/or micro-optical structures disposed on the light extraction surface of the display system (e.g., top surface of the slab waveguide), in conjunction with the point source nature of the illumination means (e.g., multiple discrete LEDs), has given rise to other optically undesirable effects, such as Moiré patterns, banding, headlighting (ability to resolve the individual light sources illuminating the display system), and other light artifacts created by using discrete light sources (e.g., LEDs) to feed light to the waveguide. These light artifacts can be sufficiently severe as to create liabilities for displays that otherwise may exhibit reasonable macro-level uniformity. It is an object of the present application to address these artifacts at the illumination source by making the light entering the waveguide sufficiently diffuse (e.g., uniform) that the periodic intensity of the original light from the individual light sources can no longer be individually resolved.

Cavity reflector light injection for flat panel displays


In a polarization rotator device, a thin-film magneto-optic medium is magnetized by a thin-film magnet. To serve as an optical isolator, the device may include polarizers. In such an optical isolator, in which the magneto-optic medium was formed as a Bi-YIG triple-layer structure, and the thin-film magnet as a single-crystal iron-cobalt layer, an extinction ratio better than -20 dB was realized.

This invention relates to magneto-optic polarization rotator structures which are suitable for inclusion in thin-film integrated optical devices.
When placed between a polarizer and an analyzer, a polarization rotator can serve as an optical isolator, e.g., for isolating a semiconductor radiation source from radiation reflected in an optical communications system. A magneto-optic polarization rotator may include a magnetic garnet medium, e.g., of single-crystal yttrium iron garnet ("YIG", Y.sub.3 Fe.sub.5 O.sub.12), magnetized in the direction of light propagation. For use in guided-wave integrated optics, for example, a rotator medium is preferably formed as a thin film on a substrate.
Background documents for the invention are reviewed as follows:
U.S. Pat. No. 5,031,983, "Apparatus Comprising a Waveguide Magneto-optic Isolator" issued Jul. 16, 1991 to J. F. Dillon et al. discloses an optical waveguide isolator including a magnetic medium in an applied magnetic field. The waveguide is formed as a multi-layer film of modified bismuth yttrium iron garnet (Bi-YIG) on a substrate of gadolinium gallium garnet ("GGG", Gd.sub.3 Ga.sub.5 O.sub.12).
U.S. Pat. No. 4,712,855, "Planar Optical Waveguide and Method of Manufacturing Same", issued Dec. 15, 1987 to W. F. M. Tolksdorf et al. discloses a multi-layer waveguide structure in which the propagation of undesired modes is inhibited. The layers are made of modified yttrium iron garnet materials.
U.S. Pat. No. 3,860,325, "Electric Field Displacing Type Optical Isolator", issued Jan. 14, 1975 to S. Matsushita et al. discloses an optical isolator based on displacement of the light path in a transverse magnetic field. With a suitably placed absorbing medium, light traveling in a waveguide in one direction is absorbed to a greater degree as compared with light traveling in the opposite direction.
U.S. Pat. No. 4,973,119, "Optical Waveguide Isolator" issued Nov. 27, 1990 to K Taki discloses a magneto-optic isolator including a multi-layer mode converter on a substrate. The converter is magnetized perpendicular to the direction of light propagation.
The paper by K. Matsuda et al., "Magnetless Faraday Rotator of (BiY).sub.3 Fe.sub.5 O.sub.12 Waveguide with Strip Magnetic Domains", Applied Physics Letters, Vol. 59, 1991, pp. 507-509 discloses a polarization rotator without a magnet, with striped magnetic domains in a Bi-YIG transmission medium.
The paper by R. Wolfe et al., "Etch-tuned Ridged Waveguide Magneto-optic Isolator", Applied Physics Letters, Vol. 56, 1990, pp. 426-428 discloses chemical etching of a triple-layer Bi-YIG film to reduce the linear birefringence in a polarization rotator, for enhanced blocking of reflected light in a magneto-optic isolator.
The paper by R. Wolfe et al., "Thin-film Garnet Materials with Zero Linear Birefringence for Magneto-optic Waveguide Devices" Journal of Applied Physics, Vol 63, 1988, pp. 3099-3103 describes causes of birefringence in epitaxial films and means for compensation.
The paper by G. A. Prinz, "Hybrid Ferromagnetic Semi-conductor Structures" Science, Vol 250, 1990, pp 1092-1097 discloses the fabrication of single-crystal films of iron and iron alloys on semiconductor substrates.
The paper by M. McGlashan-Powell et al., "Magneto-optic Waveguide Hysteresis Loops of "Planar" Magnetic Garnet Films" Journal of Applied Physics, Vol 66, 1989, pp 3342-3347 discloses a nearly in-plane easy axis of magnetization for Bi-YIG epitaxial layers.
The paper by E. Yablonovitch et al. "Epitaxial Liftoff Technology for OEIC's", American Institute of Physics, American Vacuum Society Series 10, Conference Proceedings, 1991, pp. 154-156 discloses a lift-off technique for transferring an epitaxially grown film from one substrate onto another.
The paper by D. I. Bardos, Journal of Applied Physics, Vol. 40, 1969, pp. 1371-1372 reports on hysteresis studies of iron-cobalt alloys.
Described polarization rotators and magneto-optical isolators use large magnets or solenoids to produce a magnetic field for magnetizing a magneto-optic medium. Such magnetic-field sources are not suited for integrated optics applications.

Thin-film magneto-optic polarization rotator

The Trustees of Columbia University in the City of New York


A storage apparatus which performs writing and reading of data on a magnetic tape by the helical scan method using a rotary head, in particular one suited to use with a large-sized host computer, which storage apparatus includes mainly a storage control unit connected to the host computer and a drive unit for reading from and writing on the magnetic tape. System areas are formed on the magnetic tapes, which system areas have tables which include management information relating to the magnetic tapes themselves and able to be renewed by the storage control unit. By using these tables, the magnetic tapes can be easily accessed at a high speed, diagnosed as to trouble, and managed in data blocks.

1. Field of the Invention
The present invention relates to a magnetic tape storage apparatus, and more particularly to a magnetic tape storage apparatus which can perform writing and reading of data on and from a magnetic tape using a rotary magnetic head by the so-called helical scan method.
2. Description of the Related Art
Information is frequently written and read in video recording/reproducing apparatuses using a rotary magnetic head by the helical scan method.
The technology for writing and reading information by the helical scan method can be applied not only to such video recording/reproducing apparatuses, but also to the external storage apparatuses of computer systems. With the helical scan method, it is possible to write a large volume of information on a single magnetic tape, so, for example, it is extremely advantageous to use a helical scan type magnetic tape storage apparatus as the external storage apparatus for a large-sized computer system.
Up to now, however, commercial versions of helical scan type magnetic tape storage apparatuses for use for large-sized computer systems have not appeared on the market.


The present Invention includes synthetic steps and intermediates involved in the following reaction scheme a of converting compounds of Formula (II) to the diarylmethanes of Formula (I): ##STR1## wherein: Y is oxygen or sulfur;. A, B, C, D, and E are carbon or 1, 2 or 3 of A, B, C, D, and E are independently nitrogen, and the others are carbon; and PA1 R.sup.1 through R.sup.10 are selected independently from the group consisting of: hydrogen, hydroxy, alkyl, C.sub.3 -C.sub.8 cycloalkyl, C.sub.3 -C.sub.8 cycloalkyl alkyl, alkenyl, hydroxy alkyl, alkoxy alkyl, perhalo-alkyl, amino, nitro, nitrile, halo, carboxyl, sulfonyl, acyl, formyl, carbamoyl, trifluoromethyl, aminomethyl, azido, amido, hydrazino, aryl, aryloxy, heteroaryl, or aryl or heteroaryl, mono, di, or tri substituted with one or more hydrogen, hydroxy, alkyl, C.sub.3 -C.sub.8 cycloalkyl, C.sub.3 -C.sub.8 cycloalkyl alkyl, alkenyl, hydroxy alkyl, alkoxy alkyl, perhaloalkyl, amino, nitro, nitrile, halo, carboxyl, sulfonyl, acyl, formyl, carbamoyl, trifluoromethyl, aminomethyl, azido, amido, hydrazino, aryl, aryloxy, or heteroaryl groups and;. wherein. the pharmaceutically acceptable salts and solvates thereof.

Diaryl methanes are useful as intermediates in the formation of many beneficial pharmaceutical compounds. Examples include: antihistamines, such as triprolidine and acrivastine, thromboxane synthetase inhibitors, such as furegrelate, gastric antisecretory agents, such as fenoctimine, nonsedative antidepressants, such as sertraline, antiarrhythmic agents, such as cibenzoline, topical antifungals, such as bifonazole, antimalarials, such as enpiroline, nonsteroidal antiinflammatory agents, such as bromfenac, diuretics such as brocrinat, anthelminitics, such as etibendazole and anticancer compounds, such as tamoxifen and numerous aromatase inhibitors. Examples of these can be found in 4 D. Lednicer, L. Mitscher and G. Georg, Organic Chemistry of Drug Synthesis 105, 125-35 (1990); U.S. Pat. No. 4,978,672 to Bowman et al., issued Dec. 18, 1990; and European Patent Application 0 458 160 A2, filed by Sociedad Espanola De Especialidades Farmaco-Terapeuticas, A. A. Avda., published Nov. 27, 1991.


A method for building a continuous water seal, creep line increasing cutoff includes the steps of forming spaced borings into the soil in the presence of slurry; developing narrow slots between the formed borings by driving foil boards with cutting edges secured to the bottom therof between adjacent formed borings; and connecting adjacent foil board, which extend between and are recessed into a side of the borings, by means of compensating joint-pins. The steps of developing narrow slots and connecting adjacent foil boards are repeated so that the last boring is connected to the connected, recessecd foil boards forming the cutoff. A prefered embodiment of the invention may include armoring the borings by injecting concrete in the place of the slurry.

The present invention relates to a method to build a continuous, water seal, creep-line increasing cutoff (wall), in which borings have predetermined distances therebetween and foil boards will be formed in the soil, according to the length of the cutoff and under protection of slurry.
The method comprises a first step in forming borings into the soil under protection of slurry and developing narrow slots therebetween by blowing the cutting edge secured to the bottom of foil boards, and a second step of connecting the connecting elements of foil boards recessed into the borings by means of compensating joint-pins and repeating the latter operation up to the last boring. In a preferred embodiment of the invention, armor may be set into the borings, which are then injected with concrete in the place of the slurry.
The present invention enables a cutoff to be effectively built, without the need of trenching, such a cutoff will have a creep-line increasing behavior depending on its distance to the confining bed, and a load-bearing characteristic, because of its facet-like arrangement.
The presently known methods of cutoff building appeared and started to spread in the early fiftiesxe2x80x94in the mid-sixties in Hungaryxe2x80x94, since their application for sheeting and bracing of a building pit, or building of underground structures (e.g., basements), as well as for water seal objects is more advantageous than the different conventional technologies. downwardly from the surface, then constructing the structure out of the slurry simultaneously or subsequently from the gap.
The cutoff building technology is determined by the behavior of the applied machines. Every machine which is acceptable of building a continuous, load-bearing and/or water seal wall by building-in of suitable materials in a depth beneath its moving plane, will be applicable to build such a cutoff.
Altogether, the cutting actionxe2x80x94but always in case of large cuttingsxe2x80x94involves two basic steps: excavating the soil and filling the gap.
It is possible to draw a distinction between applicable technologies according to the method of how the soil structure being in the place of the material of the wall volume is removed (carried away, respectively). Accordingly, two primary methods are known:
The ditcher applying technology has two essential characteristics, namely
the soil mellowing by the cutting tool of the ditch might be excavating from the gap to the surface by the vertical movement of the tool controlled from the ditcher.
during the excavation, the slush filling the gap might be mixed due only to the upward and downward movements of the tool.
Applying the drilling methods, only mellowing and braying of the soil are made by the cutting tool (borer, cutter, cutterhead).
The mellowed solid material admixed to the slush being in circulation is removed to the surface in form of slurry. (After backing and cleaning of the slurry, the slush is fed back into the gap.) The slush acts in this technology as an agent enhancing the stability of the gap and also excavating the solid material. This method for building a cutoff had been developed from the so-called xe2x80x98left-flushingxe2x80x99 (back-flushing) drilling technology and the appearance of bentonite suspensions having tixothrope characteristicsxe2x80x94as a drilling slush or cutting sludgexe2x80x94had had a role of vital concernment.
The aforementioned methods working with soil excavation are applicable to form wide gaps, but a narrower cutoff can be formed by compaction to the side wall of the gap, ergo without excavation of the soil. Among these methods, there is the ETF method and its developed variants having a practical relevance.
This methodxe2x80x94in substancexe2x80x94comprises a first step of longitudinally attaching injecting tubes to a high-webbed double-tee beam (or to a cutting tool having any kind of other profile), then hammering it down by machine to a depth according to the cutoff being built, and a further step of grouting contemporaneously the beginning of the cutter-flitting with an afterhardening bonding material passing through the tube (tubes) into the gap. After the solidification of the bonding material, a cutoff block is formed. Patent description HU P 94 03 231 relates to a preferred implementing of the injection and a composition of injected material(s).
The continuous cutoff consists of cutoff blocks being formed one after another, the continuity of which is established with a so called xe2x80x98cutting backxe2x80x99 action. Applying two cutting tools at the same time with the second one remaining in the soil as long as it takes for the gap of the first one to become fully injected. This technology can be advantageously achieved also by a cutting tool disclosed in the granted patent HU 167 865.
Disadvantages of these known methods are the laborsome and slow building process, and that fact, that the complete cutoff (membrane wall) has a diminished water sealing or bleeding decreasing only, not to be loaded and it can be built into a shallow depth only.
A structural embodiment of the cutoff-structures realized in the wide cuttings depends on the scope of the cutoff (whether it should be bleeding decreasing and/or load bearing too).
In some cases, the slush enabling the stability of the cutoff should act as a part of the final structure. Such a cutoff and gap filling material (cement, water, bentonite and retarding agent) are known from the patent description HU 181284.
HU 169 315 discloses a method in which prefabricated wall members are sunk into the gap sustained by a thin-liquid slurry, then the gap will be formed between the wall members and the walls of the gap shall be filled with afterhardening binder material injected into the bottom of the cutting.
In the case of concrete walls prepared in wide gaps, the continuous cutoff is typically built from sections. Such a method can be known from the patent description HU P 84 4727, this method involves a step of building a concrete wall in any section of the cutting, and a second step of locating a recoverable spacing member between this section and the cutting sustained provisionally by thin-liquid slurry, and the continuous water sealing contact is provided by a resilient, permanently located water-proof strip.
The structure and building method of a boarded-panel type cutoff comprising bearing board and sealing board is known from the patent EP 0 333 639, in which the place of the bearing boards (tubes made from steel) filled and surrounded by concrete, is made by drilling technology.
The cutoff described in the patent U.S. Pat. No. 4,304,507 is able to bear considerable loadings. The building of this cutoff takes place by making borings in predetermined distances from one another, then locating a steel beam of H shaped profile in the borings, and then excavating the place of cutoff boards by means of a pressurized water beam.
The cutoff described in the patent U.S. Pat. No. 4,304,507 is able to bear considerable loadings. The building of this cutoff takes place by making borings in predetermined distances from one another, then locating a steel beam of H shaped profile in the borings, and then excavating the place of cutoff boards by means of a pressurized water beam.
In cases obtaining greater impermeability (or bleeding decreasing), secondary sealing devices are applicable in the tixothrope or afterhardening (hardening) material filling the wide cutting.
The provisional publication DE OS 3436 735 discloses a solution, in which a plane type barrier layer interlaced with connecting elements and embedded into a wide cutting filled with suspension and having barrier element consisting of HDPE is formed.
The patent description EP O 298 283 discloses method, in which a barrier wall made of glass panels is provided and embedded into the slush of the gap. In this patent, the inner cavities of connecting links of the wall are filled by the slush.
From Hungarian published patent HU 205 177 is known a method, in which the foil sheets provided with connecting links at the edges thereof are sunk into the gap by the force exerted to the bottom part of the foil sheet (to ensure the closure of the connecting members), and thereafter a fusible material should be filled between the foil and the walls of the gap.
In the provisional publication DE OS 34 44 682, another solution is suggested, in which the wide gap is filled with a hardening sealing compound, then a narrow gap should be formed mechanically or by means of compressed water beam, and the barrier foil is placed therein.
According to a developed solution of the latter, disclosed in the patent disclosure DE 38 23 784, borings are provided in the mass filling the wide gap and posts of a slitting cutter device are guided into the borings so forming (feeding supporting liquid contemporaneously) the narrow
It can be seen from the aforementioned solutions, that each of these known methods require a time consuming and expensive soil excavation.
The methods applicable without excavation of the soil have a serious depth confinement due to the enormous friction force action between the cutting tool and the wall of the gap. In addition, the injected cutoff created this way is a lesser water-proof one (and barely loadable).
It is an object of the present invention to provide a curtain-wall, which could be built almost up to the depth measure of known cutoffs, the cutoff according to the present invention could have a good water-proof characteristic, low production costs and a short production time compared to the known solutions.
We have found that the trenchless grouting technologies combined with drilling methods are able to sink into the soil plane type sealing elements and open the narrow gap contemporaneously so that the cutoffs in progress intersect the inner space of the borings filled with slush already prepared. In this case, the side friction acting to the side walls of the sealing element will be decreased due to the slush flowing from the borings into the opening gap thereby affording an opportunity to contact the sealing element in a stress-free and water-proof way and to create a continuous cutoff.
According to this fact, the present invention relates to a method to build a continuous cutoff, in which borings having predetermined distances therebetween and foil boards having a cutting edge will be driven into the soil, according to the length of the cutoff and under the protection of slurry. The cutting edge protruding over the edges of the foil boards is secured onto the bottom of the foil boards and provided with connecting members that are well known in the art, and then the foil board is hammered down into the soil up to the desired depth by means of driving piles driven by adjacent borings and placed onto each end of the cutting edge of the foil board, and after the hammering down of a subsequent foil board, the edges of the foil boards are connected into space of the intermediate boring by means of a compensating joint-pin. These operations are repeated along the full length of the cutoff.
In a preferred embodiment of the method according to the invention, above the surface of the soil, the two driving piles working in the same stroke will be rigidly connected to each other and hammered down together.
Advantageously, in the method according to the invention, the foil boards consist of High Density Polyethylene (HDPE) material.
The compensating joint-pins connecting the foil boards are foil strips advantageously made of the same material, and having connecting members creating a form-fitting pair at their edges connecting to the connecting members of the foil boards.
In a more preferred embodiment of the method according to the invention, an armoring step that is well known in itself in the art may place armor into the borings, and the compensating joint-pins include bridles provided with connecting members, and a volume of concrete displaces the slurry that may be injected into the bottom of the armored borings.
Advantageously, the applied driving piles include inner ribs and cross-ribs forming a skirt, each cross-rib being arranged to span two opposite quadrants of a driving pile, and having a face formed by ends of the inner-ribs which converges to the centreline of the driving pile.
In a preferred embodiment of the method according to the invention, the driving pile includes a number of sections detachably jointed to each other, and the inner-ribs of the driving pile include hollowed sheets incurvated to arc at their edges.

Method to build a water seal, creep-line increasing cutoff

Szxc3xa1anth{acute over (o )}Albert u. 20


A simple system is provided for lifting ejector pins in sequence, as a knockout piston (30) is raised. First and second ejector pins (40, 42) have lower ends respectively supported on first and second ejectors (70, 72) that each can move vertically, with the second ejector lying below the first one. The second ejector has a vertical through-hole (74), and a force member (80) lies within the hole and can project both above and below the hole. As the knockout piston is moved up, it first engages the bottom of the force member to push it up, so the force member pushes up the first ejector and first ejector pin, while the second ejector and second ejector pin do not move. The top (84) of the knockout piston is wider than the hole, so when the piston reaches the bottom of the second ejector, it then begins to lift the second ejector and second ejector pin. The force member can be a cam pivotally mounted on the second ejector, or can be a shaft that moves vertically.

Parts are commonly molded by injecting a heated polymer or die casting metal through a sprue hole, along a gate, and into a cavity formed between a pair of plates. Then, the cover plate is lifted and the gate part is broken away by a first ejector pin. Finally, the molded part is ejected from the mold by one or more second ejector pins. The molding press or other equipment in which the mold lies, commonly has a single knock-out piston that moves up to raise the ejector pins. Thus, a mechanism is required which is moved by the knockout piston, to lift the ejector pins in sequence. The design of such mechanism can be complicated by the fact that the upper ends of the ejector pins may have different horizontal positions for molds used for different parts. Presently, rack and pinion mechanisms are used to move at least one of the ejector pins, but this results in complexity and parts that can be readily damaged. A molding assembly with a mechanism for lifting ejector pins in a predetermined sequence, where the ejector pins can have different horizontal positions, and which was of simple construction, would be of value.

Molding accelerated stripper-ejector system


A chromatic confocal sensor includes a light source portion that emits a plurality of light beams having different wavelengths; an objective lens that converges the plurality of light beams at different focal positions; an emission port from which measurement light reflected by an object to be measured at the focal positions out of the plurality of light beams is emitted; a position calculation portion that calculates a position of the object to be measured based on the emitted measurement light; an observation portion including an observation light source that emits observation light and an image sensor; and a beam splitter that emits at least a part of the measurement light that passes through the objective lens to the emission port and emits at least a part of the observation light that passes through the objective lens and is reflected by the object to be measured to the image sensor.

The present invention relates to a chromatic confocal sensor.
From the past, a technology of a chromatic confocal sensor has been used for measuring a height of an object to be measured, and the like. For example, US Patent Application Publication No. 2006/0109483 (hereinafter, referred to as Patent Literature 1) discloses a structure in which a microscope and a chromatic confocal sensor are integrated. As shown in FIG. 5 of Patent Literature 1, a beam splitter 6 is arranged before an objective lens 7 of the microscope. A confocal optical system including an afocal dispersion lens 5 and the like is combined with the beam splitter 6 being a starting point.


A high retention, yet relatively low insertion force and withdrawal force female disconnect receptacle is provided. The female disconnect has a pad rising from its base, preferably lanced from the base. The lancing provides a firmness to the pad interacting with the metal of the base which holds a metal tab well, with a desired low insertion force and low withdrawal force that retains and does not easily degrade upon reuse. The pad preferably has a flat bearing surface.

The present invention is a low insertion and withdrawal force metal stamped female receptacle electrical part.
In the electrical industry, it is necessary to provide parts that function with integrity and sustain their performance with integrity. There are industry standards to define performance. Standards are often set so that they can be certified.
Performance also can be tested and certified by outside organizations such as Underwriters Laboratories. Such standards organizations enable the customer and the public to be able to rely on standard compliance, the purveyor to know that standards are met and that customers can be assured of the integrity of the parts bought to comply with their needs.
Female receptacles for receiving tabs ideally should receive a tab with a low insertion force. The tab should be held with integrity and yet be easily removable. The tab ideally may be removed and reinserted. In such removal and reinsertion there must be integrity. The reinserted tab ideally should have a low insertion force and yet still be held with integrity. A problem with regard to female tab receptacles is that even though insertion and withdrawal of tabs may be satisfactory, reinsertion and withdrawal may cause a degradation of holding integrity.
The prior art interactive detents and declivities may have been effective for holding the tabs and females. They posed the double problem of high insertion and withdrawal force and the problem of rapid wear, reducing the ability of the parts to hold satisfactorily after multiple withdrawals and insertions.
The structure of the various tab receiving female receptacles and tabs of the prior art was complex to manufacture, requiring multiple steps for stamping, cutting out and bending of complex shapes.
The problem is also complex, since in electrical and electronic hardware, many suppliers may supply similar components which must be joined to different suppliers parts, yet integrity must be maintained in the assembled hardware.
A high withdrawal force in the female disconnect is desirable for retention purposes. Large surface contact is desirable for acheiving this.
The present invention fills a need, improving a well known receiving female receptacle such as described above.

High retention low insertion force electric female disconnect


A system for processing substrates has a vacuum enclosure and a processing chamber situated to process wafers in a processing zone inside the vacuum enclosure. Two rail assemblies are provided, one on each side of the processing zone. Two chuck arrays ride, each on one of the rail assemblies, such that each is cantilevered on one rail assemblies and support a plurality of chucks. The rail assemblies are coupled to an elevation mechanism that places the rails in upper position for processing and at lower position for returning the chuck assemblies for loading new wafers. A pickup head assembly loads wafers from a conveyor onto the chuck assemblies. The pickup head has plurality of electrostatic chucks that pick up the wafers from the front side of the wafers. Cooling channels in the processing chucks are used to create air cushion to assist in aligning the wafers when delivered by the pickup head.

1. Field
This Application relates to systems and methods for substrate processing, such as silicon substrates processing to form semiconductor circuits, solar cells, flat panel displays, etc.
2. Related Art
Substrate processing systems are well known in the art. Examples of substrate processing systems include sputtering and ion implant systems. While in many such systems the substrate is stationary during processing, such stationary systems have difficulties meeting recent demand for high throughput processing. The high throughput processing is especially severe for processing substrates such as, e.g., solar cells. Accordingly, new system architectures are needed to meet this demand.

This patent is subject to a terminal disclaimer.


A MTJ is disclosed with a discontinuous Mg or Mg alloy layer having a thickness from 1 to 3 Angstroms between a free layer and a capping layer in a bottom spin valve configuration. It is believed the discontinuous Mg layer serves to block conductive material in the capping layer from diffusing through the free layer and into the tunnel barrier layer thereby preventing the formation of conductive channels that function as electrical shunts within the insulation matrix of the tunnel barrier. As a result, the “low tail” percentage in a plot of magnetoresistive ratio vs Rp is minimized which means the number of high performance MTJ elements in a MTJ array is significantly increased, especially when a high temperature anneal is included in the MTJ fabrication process. The discontinuous layer is formed by a low power physical vapor deposition process.

Magnetoresistive Random Access Memory (MRAM), based on the integration of silicon CMOS with MTJ technology, is a major emerging technology that is highly competitive with existing semiconductor memories such as SRAM, DRAM, and Flash. Similarly, spin-transfer (spin torque) magnetization switching found in STT-RAM and described by C. Slonczewski in "Current driven excitation of magnetic multilayers", J. Magn. Magn. Mater. V 159, L1-L7 (1996), has recently stimulated considerable interest due to its potential application for spintronic devices on a gigabit scale.
Both MRAM and STT-RAM have a MTJ element based on a tunneling magneto-resistance (TMR) effect wherein a stack of layers has a configuration in which two ferromagnetic layers are separated by a thin non-magnetic dielectric layer. The MTJ element is typically formed between a bottom electrode such as a first conductive line and a top electrode which is a second conductive line at locations where the top electrode crosses over the bottom electrode. A MTJ stack of layers may have a bottom spin valve configuration in which a seed layer, a ferromagnetic "reference" layer, a thin tunnel barrier layer, a ferromagnetic "free" layer, and a capping layer are sequentially formed on a bottom electrode. The free layer has a magnetic moment that is either parallel or anti-parallel to the magnetic moment in the reference layer. The tunnel barrier layer is thin enough that a current through it can be established by quantum mechanical tunneling of conduction electrons. The magnetic moment of the free layer may change in response to external magnetic fields and it is the relative orientation of the magnetic moments between the free and reference layers that determines the tunneling current and therefore the resistance of the tunneling junction. When a sense current is passed from the top electrode to the bottom electrode in a direction perpendicular to the MTJ layers, a lower resistance is detected when the magnetization directions of the free and reference layers are in a parallel state ("1" memory state) and a higher resistance is noted when they are in an anti-parallel state or "0" memory state.
In a read operation, the information stored in a MRAM cell is read by sensing the magnetic state (resistance level) of the MTJ element through a sense current flowing top to bottom through the cell in a current perpendicular to plane (CPP) configuration. As the size of MRAM cells decreases, the use of external magnetic fields generated by current carrying lines to switch the magnetic moment direction becomes problematic. One of the keys to manufacturability of ultra-high density MRAMs is to provide a robust magnetic switching margin by eliminating the half-select disturb issue. For this reason, a new type of device called a spin transfer (spin torque) MRAM (STT-RAM) was developed. Compared with conventional MRAM, STT-RAM has an advantage in avoiding the half select problem and writing disturbance between adjacent cells. The spin-transfer effect arises from the spin dependent electron transport properties of ferromagnetic-spacer-ferromagnetic multilayers. When a spin-polarized current transverses a magnetic multilayer in a CPP configuration, the spin angular moment of electrons incident on a ferromagnetic layer interacts with magnetic moments of the ferromagnetic layer near the interface between the ferromagnetic and non-magnetic spacer. Through this interaction, the electrons transfer a portion of their angular momentum to the ferromagnetic layer. As a result, spin-polarized current can switch the magnetization direction of the ferromagnetic layer if the current density is sufficiently high, and if the dimensions of the multilayer are small. The difference between a STT-RAM and a conventional MRAM is only in the write operation mechanism. The read mechanism is the same.
A high performance MRAM MTJ element is characterized by a high tunneling magnetoresistive (TMR) ratio which is dR/R (also known as DRR) where R is the minimum resistance of the MTJ element and dR is the change in resistance observed by changing the magnetic state of the free layer. A high TMR ratio and resistance uniformity (Rp_cov), and a low switching field (Hc) and low magnetostriction (λs) value are desirable for conventional MRAM applications. For Spin-RAM (STT-RAM), a high λs and high Hc leads to high anisotropy for greater thermal stability. This result is accomplished by (a) well controlled magnetization and switching of the free layer, (b) well controlled magnetization of a reference layer that has a large exchange field and high thermal stability and, (c) integrity of the tunnel barrier layer. In order to achieve good tunnel barrier properties such as a specific junction resistance×area (RA) value and a high breakdown voltage (Vb), it is necessary to have a uniform tunnel barrier layer which is free of pinholes. Furthermore, electrical shunting must be minimized to avoid undesirable degradation of the magnetoresistive (TMR) ratio.
An electrical shunt is often observed as a "low tail" in the DRR (TMR ratio) vs. resistance in parallel state (Rp) plot as shown in FIG. 1. The cluster 3 of data points outside the main population 2 and spreading toward zero DDR and zero Rp is defined as the "low tail". MTJs with this low tail population are undesirable for STT-MRAM applications since they have a small DRR as well as low Rp. This result occurs because as the electrical short (shunt) becomes greater, more current passes through the shunting pathways and does not contribute to tunnel magnetoresistance.
To our knowledge, current MTJ technology does not provide a means of minimizing the number of MTJ elements with a "low tail" character while maintaining high DRR. Therefore, an improved MTJ structure is needed to reduce the occurrence of electrical shunting which will in turn increase the yield of "good" MTJs that are acceptable for high performance devices.

Mg discontinuous insertion layer for improving MTJ shunt


Method and system for evaluating sheet metal forming tooling design, for use with a draw die including a punch and binder designed to form the sheet metal into a part, utilizing improved implicit time integration methods that reduce numerical instability, thereby enhancing convergence of numerical solutions. The sheet metal and tool surface of the punch are each represented as a mesh having a plurality of nodes. Contact nodes between the sheet metal mesh nodes and the tool surface mesh can be identified. A first embodiment includes minimizing discontinuities generated by unloading by determining a stress increment of a sampling point in the sheet metal mesh according to an incremental deformation theory of plasticity. A second embodiment includes modelling a draw-bead as a plurality of nonlinear elastic springs to minimize discontinuities in the spring force during unloading. A third embodiment includes filtering a relative velocity vector of at least one contact node with respect to the tool surface, to avoid frictional force oscillations due to the change in direction of the relative velocity vector during formation of the part.

The conventional draw process to form a sheet into a part is generally divided into two stages: the binder-wrap stage and the punch and die closure stage. The traditional method for sheet metal forming analysis is a quasi-static method. Due to the low speed of tool travel (e.g. less than 250 mm/S), the inertia effect of a thin sheet can be ignored. As a result, a quasi-static analysis can be justified and solved by the incremental method following the progress of tool movement.
A quasi-static analysis in three-dimensional space of the punch and die contact is described in the article titled "Analysis of Sheet Metal Stamping by a Finite-Element Method" authored by N. M. Wang and B. Budiansky, published by the Journal of Applied Mechanics, Vol. 45, No. 1, March 1978. The contribution of their method solved a contact problem the quasi-static analysis by taking material derivatives of the contact forces. This, however, requires the curvature of tool surfaces, which is hard to obtain numerically. In addition, the coefficient matrix of the modified linear system governing the increment deformation of the sheet is no longer symmetric. The solution process was linearized by dividing the total punch travel distance into sufficiently small increments such that within a small interval the incremental equilibrium equation, which is approximately linear, could be solved. The method however, was based on the membrane shell theory, which has severe limitations, and the method cannot be applied to the analysis of a draw forming operation.
More recently, attempts have been made to analyze the punch and die contact utilizing crash worthiness programs based on an explicit time integration method. These programs are appropriate for structures dominated by an inertia load, such as the transient response to an automobile crash. As a result, the explicit time integration method yields inaccurate results for a sheet forming analysis without artificial adjustments for forming speeds and damping parameters which are problem dependent.
Due to severe discontinuities and the occurrence of structural instability, traditional numerical solutions often have convergence problems. It would be desirable to address and resolve these convergence problems, so as to avoid undesirable oscillation in the transient response during forming, utilizing a more reliable implicit time integration method.

Method for aiding sheet metal forming tooling design


Adenosine compounds having the following structure ##STR1## wherein X is halogen, perhalomethyl, acetamido, cyano, C.sub.1-6 -alkoxy, C.sub.1-6 -alkylthio or C.sub.1-6 -alkylamino; and. R.sup.1 is --NR.sup.2 R.sup.3 or YR.sup.4, wherein Y is oxygen or sulfur;. R.sup.2 is phenyl, C.sub.1-6 -alkyl or substituted C.sub.1-6 -alkyl; and. R.sup.4 is naphthyl, partly saturated naphthyl; optionally phenyl or phenoxy substituted C.sub.1-6 -alkyl wherein the phenyl and phenoxy substituents are also optionally substituted, or optionally phenyl or phenoxy substituted C.sub.3-8 -cycloalkyl and their pharmaceutically acceptable salts are useful in the treatment of myocardial and cerebral ischemias.

Adenosine can be considered to be a hormone which has been shown to have a number of significant effects on the mammalian central nervous system [Annual Reports in Medicinal Chemistry, 1988, 23, 39-48; International Review of Neurobiology (Smythies, J. R. and Bradley, R. J., eds.) Academic Press Inc., 1985.27, 63-139], especially under conditions of neuronal stress where the compound appears to act as an endogenous neuroprotectant (Progress in Neurobiology, 1988, 31,85-108, Trends in Pharmacological Sciences, 1983, 9, 193-194). For example, the concentration of adenosine has been demonstrated to rise greatly in certain brain regions following epileptic seizures or ccnditions of neuronal ischaemia/anoxia (Brain Research 1990, 516, 248-256).
It has been established for some years now that centrally acting adenosine receptor agonists or compounds which increase extracellular adenosine levels can exhibit what is termed neuromodulator activity. Such substances influence the release of neurotransmitters in regions of the central nervous system (Annual Review of Neuroscience, 1985, 8, 103-124; Trends in Neurosciences, 1984, 164-168), with particular inhibitory effects on the release of the excitatory amino acid glutamic acid (glutamate) (Nature, 1985, 316, 148-150, Journal of Neurochemistry, 1992, 58, 1683-1689).
There are several CNS ailments for which this adenosine receptor mediated neuromodulator activity could be of clear therapeutic benefit. Examples of these would include the treatment of convulsive disorders (European Journal of Pharmacology, 1991, 195, 261-265; Journal of Pharmacology and Experimental Therapeutics, 1982, 220, 70-76), prevention of neurodegeneration under conditions of brain anoxia/ischaemia (Neuroscience Letters, 1987, 83, 287-293; Neuroscience, 1989, 30, 451-462; Pharmacology of Cerebral Ischaemia 1990 (Kriegelstein, J. and Oberpichler, H., Eds., Wissenschaftliche Verlagsgesellschaft mbH: Stuttgart, 1990, pp 439-448) or the use of a purinergic agent in the treatment of pain (European Journal of Pharmacology, 1989, 162, 365-369; Neuroscience Letters, 1991, 121, 267-270). In addition, the antiischaemic effect of the compounds described within this invention may be useful in protecting against cardiac ischaemia.
Adenosine receptors represent a subclass (P1) of the group of purine nucleotide and nucleoside receptors known as purinoreceptors. This subclass has been further classified into two distinct receptor types which have become known as A1 and A2. Extensive research has been carried out in a quest to identify selective ligands at these sites [see, for example, Comprehensive Medicinal Chemistry Volume 3, (Hansch, C., Sammes, P. G. and Taylor, J. B., Eds., Pergamon Press PLC: 1990, pp 601-642)]. Selective ligands exist for A1 and A2 adenosine receptors and the structure-activity relationships of the various reference ligands have been reviewed (Biochemical Pharmacology, 1986, 35, 2467-2481) together with their therapeutic potential (Journal of Medicinal Chemistry, 1992, 35, 407-422). Among the known adenosine receptor agonists most selective for the A1 receptor over the A2 receptor are the examples where the adenine nucleus is substituted with a cycloalkyl group on the amino function, for example N-cyclopentyladenosine and N-cyclohexyladenosine (Journal of Medicinal Chemistry, 1985, 28, 1383-1384) or 2-chloro-N-cyclopentyladenosine (Naunyn-Schmiedeberg's Arch pharmacal. 1988, 337, 687-689).
Examples of adenosine derivatives in the chemical literature with the heteroatoms, oxygen or nitrogen bonded directly to the 6-amino substituent are summarised below.
Examples with hydrogen at the purine 2-position include N-aminoadenosine, N-[(N-methyl-N-phenyl)amino]adenosine, N-hydroxyadenosine, N-methoxyadenosine and N-benzyloxyadenosine (Journal of Medicinal Chemistry, 1985, 28, 1636-1643); N-ethoxyadenosine (Chemical and Pharmaceutical Bulletin, 1973, 21, 1676-1682; ibid., 1973, 21, 1835-1838); N-(methylamino)adenosine and N-[(N-hydroxy-N-methyl)amino]adenosine (Journal of Medicinal Chemistry, 1968, 11, 521-523).
Examples of adenosine derivatives with oxygen or nitrogen atoms bonded to the 6-amino substituent, containing an additional purine 2-substituent are 2-amino-N-hydroxyadenosine (Journal of Medicinal Chemistry, 1972, 15, 387-390); 2-amino-N-aminoadenosine (Chemical and Pharmaceutical Bulletin, 1969, 17, 2373-2376); 2-amino-N-methoxyadenosine (Chemical and Pharmaceutical Bulletin, 1975, 23, 464-466); 2-chloro-N-hydroxyadenosine (Journal of Medicinal Chemistry, 1991, 34, 2226-2230), 2-fluoro-N-aminoadenosine (Journal of Medicinal Chemistry, 1970, 13, 427-430) and 2-fluoro-N-hydroxyadenosine (Journal of Medicinal Chemistry, 1971, 14, 816-819).
In the above scientific articles, no mention is made of any pharmacological effects of the compounds concerned on the central nervous system.
In U.S. Pat. No. 3,819,613, substituted adenosine analogues with hydrazone derivatives on the 6-amino function are disclosed as hypotensive agents. In GB 1,351,501, adenosine and 2-aminoadenosine derivatives having a --NH--R.sub.2 group joined to the 6-amino function are disclosed as coronary dilators and platelet aggregation inhibitors. In EP A 152,944, a series of 2-, 6- and 8-substituted adenosine derivatives are described having activity as anti-allergy agents. In EP A 253,962, adenosine and 2-haloadenosine analogues having an alkyl, cycloalkyl or an aralkyl group attached to the 6-amino function are described with activity as anti-dementia agents. In EP 402,752A, derivatives of adenosine unsubstituted in the 2-position are described which have a substituted heteroaromatic 1-pyrrolyl moiety attached to the 6-amino group. In WO 91/04032, methods of preventing neural tissue damage in neurodegenerative diseases by increasing extracellular concentrations of adenosine are described. Examples are given of prodrug esters of AICA riboside (5-amino-1-.beta.-D-ribofuranosyl)imidazo-4-carboxamide) which are claimed to be centrally acting neuroprotective agents. In WO 92/02214, analogs of AICA riboside are revealed for the treatment of myocardial and cerebral ischaemias. In WO 90/05526, 2-(alkylalkynyl)adenosine derivatives are described for treatment of ischaemic disease of the heart and brain.
The present invention relates to new adenosine analogues having potent binding in vitro to the adenosine A1 receptor, and at the same time showing selectivity for A 1 receptor binding in vitro over that to the A2 receptor subtype. In addition, many of the novel compounds contained in this invention have a relatively high lipophilicity, especially when compared to adenosine analogues and adenosine itself which are not substituted on the 6-amino group or the purine 2-position. This latter property may make these compounds suitable for passage across the blood brain barrier.
The possibility that some of the compounds may be substrates for nucleoside-specific active transport systems into the CNS across the blood barrier is, however, not excluded. These useful properties support the notion that some of the examples may have potential as candidate drugs for treatment of the CNS ailments mentioned within this invention in humans.
The compounds of the invention are purine derivatives of formula I, or a pharmaceutically acceptable salt thereof: ##STR2## wherein
X represents hydrogen, halogen, amino, perhalomethyl, acetamido, cyano, C.sub.1-6 -alkyl, C.sub.1-6 -alkoxy, C.sub.1-6 -alkylthio or C.sub.1-6 -alkylamino;
R.sup.1 is --NR.sup.2 R.sup.3, --YR.sup.4,
wherein Y is oxygen or sulphur;
R.sup.2 is C.sub.1-6 alkyl;
R.sup.3 is phenyl or C.sub.1-6 -alkyl, which may be substituted with phenyl or phenoxy;
R.sup.4 is naphthyl;
partly saturated naphthyl;
C.sub.1-6 -alkyl, which may be substituted with phenoxy or phenyl, which may be substituted with nitro, halogen or amino;
or C.sub.3-8 -cycloalkyl, which may be substituted with phenyl or phenoxy;
In certain examples, the group R.sup.1 can contain one or more asymmetric carbon atoms in addition to those asymmetric centres already present in the molecule. In examples where this is the case, this invention includes all resulting diastereoisomers and mixtures thereof.
Various salts of compounds of formula (I) can be prepared which can be considered physiologically acceptable. These include addition salts derived from inorganic or organic acids, for example, acetates, fumarates, glutarates, glutaconates, lactates, maleates, methanesulphonates, phosphates, salicylates, succinates, sulphates, sulphamates, tartrates and paratoluenesulphonates. In some cases, solvates of either the free nucleosides or the acid addition salts can be isolated and these solvates may, for example, be hydrates or alcoholates.
Compounds of formula (I), which act as adenosine receptor agonists, are found to be useful in the treatment of central nervous system conditions such as anxiety, neuronal ischaemia/anoxia, convulsive disorders (epilepsy) and neurodegeneration (including Parkinson's disease).
Further, the compounds of formula (I) are found to be useful as analgesic agents, in lowering plasma free fatty acid (FFA) levels or as cardiovascular agents and also have application to myocardial ischaemia.
The invention also relates to methods of preparing the above mentioned compounds. These methods comprise:

2-chloro-N.sup.6 -substituted adenosines, their pharmaceutical compositions, and activity in treating ischemias