The present invention provides a nickel nanowires-containing paste having an adequately high thermal curing rate even under comparatively low temperature, which is excellent in functional properties such as an electrical conductivity, strength properties (in particular, a bending property), a water-resisting property, a salt water-resisting property and electromagnetic-wave shielding properties, from which a cured structure excellent in an electrical conductivity can be obtained even if it is stored for a long time. The present invention relates to a paste comprising nickel nanowires, an alkoxy-alkylated polyamide and a glycol.

Utilization of nanowires as a nanotechnology material in a variety of fields is being studied, and for example, employment of the nanowires in a fine wiring of an electronic material, a sensor, a solar battery etc. is expected. As the electronic material, an epoxy resin is general as a binder that binds electrically conductive materials. However, in recent years, from a viewpoint of curing on a flexible polymer substrate and energy saving, curing at a lower temperature has been demanded, but since the epoxy resin has a high thermal curing temperature, and is limited in use, one having a high thermal curing rate even under comparatively low temperature has been required.
Moreover, since silver nanowires widely known as nanowires are made of a noble metal, the cost is very high, and ion migration easily occurs. Since copper nanowires that are known next to the silver nanowires are apt to rust, there is a problem that they cannot be formulated into a dispersion such as a paste, or are bad in a durability as a dispersion. For this reason, both nanowires have been limited in practical use.
The present inventors disclosed nickel nanowires as nanowires that have a high ion migration-resisting property, and are difficult to rust (for example, Patent Literature 1 etc.). However, since the nickel nanowires react with oxygen in the air or the liquid to form a passive layer on the surface, there has been a problem that even when the nickel nanowires are incorporated into a structure as it is, a sufficient electrical conductivity is not obtained in an electric wiring etc.
Meanwhile, a method of obtaining a sufficient electrical conductivity by reducing nickel nanowires themselves has been disclosed as in Patent Literature 2. However, in a structure of the nickel nanowires obtained by such a method, there have been a variety of problems, such as that it is brittle, generates gaps due to cracking etc., and is unsuitable in utility in which it is made to function as a plane, such as electromagnetic-wave shielding.
For example, when a polymer that dissolves in a glycol, such as polyvinylpyrrolidone, is added as a binder, the binder dissolves in a solvent such as water and an alcohol having a high polarity like a glycol. Therefore, a structure obtained from a paste containing nickel nanowires, a binder and a glycol could not be used outdoors or in water that requires a water-resisting (sea water) or for medical applications that are sterilized with a chemical solution such as an alcohol is performed, or the like. For this reason, in the structure, a special protective layer that is high in a water-resisting property and an alcohol-resisting property, and is low in a water permeability and an alcohol permeability has been required.
Furthermore, for example, when a monomer or a polymer having a curing property, which contains an epoxy group or an isocyanate group etc., is added as a binder, since glycols have a high boiling point and, further, have active hydrogens, it is difficult to control a curing reaction thereof, and the binder incorporates a glycol partially and cures. For this reason, a paste containing nickel nanowires, a curable binder and a glycol has had a problem that a structure after curing is brittle, a shape cannot be maintained, contact between nanowires cannot be secured to show an electrical conductivity and electromagnetic-wave shielding properties, and so on.


A radiation-sensitive composition for use in printing plates is described. The composition comprises: (a) at least one novolak; (b) at least one naphthoquinone diazide derivative; and (c) a copolymer comprising units A, B, and a unit C comprising a cyclic terminal urea group, wherein unit A is present in an amount of about 5 to about 50 mol % and has the formula  is represented by                wherein R1 is selected such that the homopolymer of A is alkali-soluble, unit B is present in an amount of about 20 to about 70 mol % and has the following formula  is represented by        wherein R2 is selected such that the homopolymer of B has a glass transition temperature greater than 100° C., preferably a glass transition temperature in the range from about 100 to about 380° C., and the unit C comprising a cyclic terminal urea group is present in an amount of about 10 to about 50 mol % and has the formula  is represented by        wherein X is a spacer group which is preferably selected from the group consisting of (a) a —(CR2)m— chain, (b) a —[CH2—CH2—O]m— chain; and (c) a —[Si(R2)—O]m— unit, wherein m is an integer greater than or equal to 1, more preferably between 2 and 12, the spacer group is connected to one of the carbon ring atoms of the cyclic urea unit or to one of the nitrogen atoms of the cyclic urea unit, and n is an integer greater than or equal to 1, more preferably between 1 and 5; and        Y is a group selected from the group consisting of:          wherein each R in units A, B, and C, the —(CR2)m— chain, the —[Si(R2)—O]m— unit, and group Y  represents a bond between the cyclic urea and the spacer group X, or is independently selected from hydrogen, aryl, (C1-C12) alkyl, and  or halogen.

1. Field of the Invention
The present invention relates to solvent resistant polymers for use in printing plates, and printing plates employing such polymers. In particular, the present invention relates to a polymer having a monomeric unit comprising a cyclic terminal urea group, which renders the polymer bakeable, and a printing plate employing such a polymer.
2. Background Information
Recently, the resistance of offset printing plates to solvents and common printing room chemicals such as plate cleaning agents or rubber blanket washing agents as well as to alcohol substitutes in the fountain water has had to meet ever increasing demands. Particularly in printing processes using UV-curing inks, where rinsing agents with a high content of esters, ethers or ketones are used, the chemical resistance of conventional positive working printing plates is no longer sufficient without special stabilizing processes. To improve the chemical resistance of positive working offset printing plates, three approaches have essentially been discussed:                1) In the most basic case, positive working offset printing plates comprise two components, namely a naphthoquinone diazide (NQD) derivative and a novolak. One possibility is to chemically alter the NQD such that it has an increased chemical and solvent resistance (e.g. U.S. Pat. No. 5,609,983). The disadvantage of this method is that the resistance of a printing plate produced therefrom cannot be increased indefinitely by increasing the NQD content since the NQD content must lie in a certain range to be viable from a practical point of view.        2) Another approach is to thermally stabilize a conventional positive working printing plate (based on novolak and NQD). This can be carried out either by "baking" or by means of the Pulsar™ process. During baking, a completely developed printing form is heated to about 230° C. for a few minutes causing the mostly phenolic binders to cross-link. This results in an extremely high chemical and mechanical resistance. In the Pulsar™ process, the developed printing plate is subjected to a short-time "shock heating" to about 175° C. This results in a slight cross-linking (and thus an increase in the chemical resistance) of the image areas. For the user, the two thermal stabilizing processes entail the important disadvantage that they require somewhat complicated apparatuses and are therefore quite costly.        3) A third option is the change of the binder content of a radiation-sensitive composition. For example, additives can be added to the formulation. However, in the case of commercially available additives, the amount to be added is often limited since these substances are not adapted to the composition and therefore often affect the properties of the printing plate when added at too high a concentration.
Another frequently used method is the use of higher molecular novolaks; however, this leads to a deterioration of the photosensitivity of the composition which leads to a considerable loss of time for the user, particularly in the case of high numbers of prints or when so-called "Step & Repeat" exposure machines are used.
Furthermore, the properties of the binders in the photosensitive composition can be improved by way of chemical modification. Such special binders with a high degree of chemical resistance are either not commercially available or very expensive. Accordingly, it is often necessary for manufacturers to develop their own binders. To avoid high costs in the developing process, efforts must be made to keep the synthetic requirements for preparing such tailor-made high-performance binders as simple as possible.
For example, U.S. patent application Ser. No. 09/630,920  U.S. Pat. No. 6,475,692 describes radiation-sensitive compositions which significantly increase the chemical resistance of printed circuit boards for integrated circuits, photomasks and in particular printing forms. However, the compositions of U.S. patent application Ser. No. 09/630,920  U.S. Pat. No. 6,475,692 are not bakeable, which means they do not harden upon heating. The chemical resistance to solvents of the urea-containing copolymers is even higher than for the polymers described in U.S. patent application Ser. No. 09/630,920  U.S. Pat. No. 6,475,692.
JP 90/91752 describes a solvent resistant polymer comprising epoxide functionalities. The polymer is not described as being suitable for thermal applications.
JP 88/121546 describes polymers suitable for UV-ink plates. The polymers contain amide and carboxylic acid groups, but no urea groups.
EP 0 737 896 discloses solvent resistant polymers. The polymers do not contain terminal urea groups and are not described as being bakeable or suitable for thermal applications.
Therefore, despite intensive research in the field of chemically resistant binders for offset printing plates, there is a need in the art for a radiation-sensitive composition with high solvent resistance for use in printing plates. It is an object of this invention to provide such a radiation-sensitive composition. It is another object of this invention to provide a printing plate having such a radiation-sensitive composition.

Solvent resistant polymers with improved bakeablity features


A high speed solenoid valve that has a housing with an inlet and outlet that are typically connected to a pneumatic system to control the flow of air across the valve. The solenoid has a first magnetic core coaxial with an armature. Wrapped around the first core is a coil that is connected to a source of power. The coil emits a magnetic flux when current flows through the coil. Adjacent to the coil is a second magnetic core that is attached at one end to the first core and spaced from the opposite end of the first core by a first bushing. Attached to the armature is a magnetic plate that is adjacent to the spaced apart ends of the first and second cores. When the coil is energized, the magnetic flux flows through the magnetic cores and plate, pulling the plate toward the cores and moving the armature from a first to a second position. The solenoid valve has a rod that is adjacent to the armature, such that the rod is moved from a first position to a second position by the armature, when the plate is pulled by the magnetic field of the coil. A spring is attached to the rod to push the rod and armature into the first position when the coil is deenergized. The rod has a first spool at one end which is seated on a second bushing, such that the first spool prevents fluid communication between the housing inlet and outlet when the rod is in the first position. When the coil is energized and the rod is moved into the second position, the first spool is unseated from the second bushing to allow air to flow through the valve.

1. Field of the Invention
This invention relates to solenoids typically used to control the flow of a fluid.
2. Description of Related Art
Solenoids are used in a variety of applications, such as flow control valves in a hydraulic or pneumatic system. Typically solenoid valves are placed between a pump or compressor and an actuator, such that the valve will allow fluid to flow to the actuator when the solenoid is energized. The flow of fluid causes the actuator to extend, retract or rotate, depending upon the construction of the actuating device. The actuator can be part of a robot or other automated equipment, wherein movement of the actuator performs some type of work function such as lifting, drilling, etc.
Automated machines commonly have a plurality of actuators and solenoids all connected to an electronic controller, which energizes the solenoids in accordance with a program stored within the controller. In some applications the movement of the actuator is dependent upon the amount of time that the solenoid is energized. Typically, there is a lag between the time that the solenoid is energized and the moment when the valve is opened. To have an accurate movement of the actuator, this lag time must be compensated for by the programmer. The lag time is amplified by any inefficient use of the magnetic flux generated by the coil. It would therefore be desirable to have an efficient solenoid that has a short time difference between the energizing of the solenoid coil and the complete movement of the solenoid armature.
In general, all valves have a number of moving parts that are subject to wear and must be replaced, thereby reducing the life of the device. When the valve is part of a machine, the equipment must be shut down while the valve is replaced or repaired. As the frequency of valve switching increases, the life of the part becomes shorter. It would therefore be desirable to have a high speed solenoid valve which has a long operating life.


An optical switch for switching an optical path of an input optical signal comprises a substrate composed of a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams and formed in parallel to one another on the separation layer and connected at their tip ends to a connection member, at least one silica glass optical waveguide core formed on the cantilever beams, a plurality of optical waveguide fixed in opposition to the silica glass optical waveguide core, a cover for covering the cantilever beams, and a switch drive unit for bending the cantilever beams. The switch drive unit comprises electromagnetic actuators, which comprise soft magnetic bodies formed on the connection member for the cantilever beams and on the substrate, soft magnetic yokes formed of a soft magnetic body, permanent magnets, and wire coils.

The present invention relates to a waveguide type optical switch that is employed in the field of optical communication, and more particularly to a waveguide type optical switch which is small in size and suitable for remote control.
Among conventional waveguide type optical switches is a 1xc3x972 optical switch disclosed in Japanese Patent Unexamined Publication No. 6-148536. This 1xc3x972 optical switch has a cantilever beam formed on a silicon substrate, and serves to perform optical path switching by moving an optical waveguide formed on the cantilever beam with the use of electrostatic force.
In the aforementioned optical switch the following points have not been taken into consideration.
First, the use of electrostatic force requires the drive volt is as high as tens of volts or more, and a single-cantilever beam structure for the optical switch involves turning of a tip end of the waveguide concurrently with translating motion at the time of optical switching operation, which causes non-parallelism of the optical entrance plane and optical exit plane of the waveguide, leading to an increased loss of insertion. In addition, a substrate is formed of silicon, and so if silica glass is used as a material for the optical waveguide, the waveguide will be distorted or cracked due to a difference between the linear expansion coefficients of the both components.
It is an object of the present invention to solve the above problems and provide a waveguide type optical switch which can be driven with a voltage of 10 volts or less and which is small in insertion loss and low in cost.
To achieve this end, an optical waveguide switch according to the present invention comprises a silica glass substrate; a plurality of cantilever beams formed in parallel to one another on the silica glass substrate, and connected at their tip ends to a connection member; at least one input silica glass optical waveguide core formed on the cantilever beams; a plurality of output optical waveguide cores fixed in opposition to the input silica glass optical waveguide core; and switch drive means for bending the cantilever beams.
Further, the invention provides an optical switch for switching an optical path of an input optical signal, comprising a silica glass substrate, a separation layer formed on the silica glass substrate, a plurality of cantilever beams formed in parallel to one another on the separation layer, and connected at their tip ends to a connection member, at least one input silica glass optical waveguide core formed on the cantilever beams, a plurality of output optical waveguide cores fixed in opposition to the input silica glass optical waveguide core, and switch drive means for bending the cantilever beams.
The thickness of the separation layer is less than a height of the input optical waveguide core, and at least one of the connection member or those members on the substrate which are disposed to be brought into contact with the connection member when an optical-path switching operation is performed are recessed in a movement direction of the connection member.
The switch drive means comprises soft magnetic bodies provided on the connection member for the cantilever beams and on the substrate, and an electromagnetic actuator comprising a soft magnetic yoke provided on the substrate and formed of a soft magnetic body, a permanent magnet, and a wire coil.
The soft magnetic yoke is divided to form an interior yoke formed of a soft magnetic body, and an exterior yoke formed of a soft magnetic body and opposed to the interior yoke through a cover formed with an insertion hole for an index regulating liquid.
With the above arrangement, a plurality of cantilever beams formed in parallel to one another and connected at their tip ends to the connection member function to have their tip ends moved parallel with one another when an optical-path switching operation is performed.
Therefore, the tip end portions of the optical waveguides formed on the cantilever beams are also moved parallel with one another upon the optical-path switching operation. This parallel movement of the optical waveguides makes selection of an output optical waveguide to enable optical path switching.
In the present invention, the silica glass optical waveguides are formed on a silica glass substrate, which can make the difference in liner expansion coefficient between the substrate and the optical waveguide layer extremely small, and consequently it is possible to suppress warp and deformation of the substrate and cantilever beams to accurately position the optical waveguides on the emergent and incident sides.
In the present invention, the separation layer provided on the whole or part of the silica glass substrate is removed by etching, and so movable cantilever beams separated from the substrate can be obtained with ease and in a short time.
In the present invention, a press member fixed to the substrate crosses at least one of the tip ends of the cantilever beams, and so there is no possibility that the cantilever beams will be separated from the substrate in a vertical direction.
In the present invention, the cover for covering the whole of cantilever beams allows an index regulating liquid to fill around the cantilever beams and their vicinities and eliminates the possibility of adherence of foreign matters which may hinder a switching operation, and so high reliable switching can be performed.
In the present invention, the thickness of the separation layer is less than the height of the optical waveguide, and so even if there were any positional discrepancy equivalent to the gap between the silica glass substrate and the cantilever beam after removal of the separation layer, there would be no possibility that the ends of the facing optical waveguides were completely displaced from each other and therefore the optical coupling would be maintained. Accordingly, even in the case where the cantilever beam is displaced by external disturbance, an extreme reduction in the optical coupling efficiency can be suppressed.
In the present invention, at least one of the connection member or those members on the substrate which are disposed to be brought into contact with the connection member when an optical-path switching operation is performed are recessed in a movement direction of the connection member to thereby limit the contact area to a small magnitude. Furthermore, it is possible to suppress the index regulating liquid from entering portions, with which the connection member and the aforementioned member on the substrate contact, to form a gap therebetween.
In the present invention, magnetic forces are generated between the soft magnetic body formed on the connection member for cantilever beams and above the substrate, and wire coils and the permanent magnet, and can be utilized to deform the cantilever beam to thereby switch the optical waveguide formed on the cantilever beam.
Further, in the present invention, the soft magnetic yoke formed of a soft magnetic body and constituting a part of a magnetic circuit can be divided to provide an interior yoke formed of a soft magnetic body and provided on the substrate, and an exterior yoke formed of a soft magnetic body and opposed to the interior yoke with the cover therebetween, so that it is possible to form only the interior yoke inside the cover enclosing the entire cantilever beam and the exterior yoke outside the cover. With this arrangement, the wire coil and the permanent magnet are not received within the cover, so the cover can be reduced in size and also foreign matters possibly produced from the permanent magnet and the wire coil can be prevented from adhering to the cantilever beam and their vicinities.
Further objects and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings.

Optical switch, method of manufacturing same, and optical communication equipment using same


A semiconductor integrated circuit device includes a flat-range voltage supply unit which steps down an external power supply voltage and generates a resultant, flat-range voltage, and a burn-in voltage supply unit which generates a burn-in voltage depending on the external power supply voltage. A switching unit selects either the flat-range voltage or the burn-in voltage, a selected voltage being supplied to an internal circuit. A switching instruction unit includes switches and generates a switching instruction signal by an ON/OFF control of the switches. A switching control unit controls the switching unit in accordance with the switching instruction signal.

1. Background of the Invention
The present invention generally relates to semiconductor integrated circuit devices and methods for testing the devices. More particularly, the present invention is concerned with a semiconductor integrated circuit device having a flat-type on-chip step-down power supply circuit, and a method for performing a burn-in (acceleration) test in which an external power supply voltage exceeding the normal operation range is applied to the device in order to detect initial faults in the device.
A recent requirement of increasing the integration density of semiconductor integrated circuit devices need more miniaturized MOS transistors formed in the device. The miniaturized MOS transistors may encounter a problem about reliability. More particularly, the miniaturized MOS transistors have an increased electric field between the source and drain, which causes a hot carrier functioning to prevent the transistors from performing the transistor operation.
Recently, there has been proposed a semiconductor integrated circuit device equipped with an on-chip step-down power supply circuit in order to ensure resistivity to the hot carrier. The on-chip step-down power supply circuit receives an external power supply voltage and steps it down to thereby generate a reduced power supply voltage.
Though various on-chip step-down power supply circuits are known, they can be grouped into the following two types:
(1) a flat-type circuit capable of maintaining the step-down voltage at an approximately constant level even if the external power supply voltage varies; and PA1 (2) a circuit generating the step-down voltage varying based on a variation in the external power supply voltage. PA1 a flat-range voltage supply unit which steps down an external power supply voltage and generates a resultant, flat-range voltage; PA1 a burn-in voltage supply unit which generates a burn-in voltage depending on the external power supply voltage; PA1 a switching unit which selects either the flat-range voltage or the burn-in voltages a selected voltage being supplied to an internal circuit; and PA1 a switching instruction unit which includes switches and generates a switching instruction signal by an ON/OFF control of the switches; and PA1 a switching control unit which controls the switching unit in accordance with the switching instruction signal. PA1 flat-range voltage supply unit which steps down an external power supply voltage and generates a resultant, flat-range voltage; PA1 a burn-in voltage supply unit which generates a burn-in voltage depending on the external power supply voltage; PA1 a switching unit which selects either the flat-range voltage or the burn-in voltage, a selected voltage being supplied to an internal circuit; and PA1 a switching instruction unit which includes first and second switches and generates a switching instruction signal by an ON/OFF control of the first and second switches; and PA1 a switching control unit which controls the switching unit in accordance with the switching instruction signal, the method comprising the steps of:
As compared with the latter type, the step-down power supply circuit of the flat type is widely employed because the step-down voltage internally generated is maintained at an approximately constant level irrespective of a variation in the external power supply voltage and contributes to stability of the performance.
However, a problem will occur when a burn-in test (voltage accelerating test) is carried out for semiconductor devices equipped with the flat-type step-down circuit. In the burn-in test, a voltage exceeding the normal operation voltage range for internal circuits on the chip is applied to the device for a predetermined time. The normal transistors forming the internal circuits are not affected by such a high voltage. Defective transistors are rapidly degraded. After the application of the high voltage, it is determined whether there are such defective transistors. The devices having defective transistors are discarded. When the high-voltage for the burn-in test is applied to the semiconductor device equipped with the flat-type step-down power supply circuit, the circuit does not produce the step-down voltage higher than the normal operation voltage. Hence, the burn-in test cannot be carried out for semiconductor devices equipped with the flat-type step-down power supply circuits. Hence, it is desired that the above problem be overcome.
2. Description of the Related Art
FIG. 1 is a circuit diagram of an on-chip step-down power supply circuit related to the present invention. A regulator unit 14 receives an input voltage V.sub.D and supplies a regulated power supply voltage to an internal circuit (not shown for the sake of simplicity). A flat-range voltage supply unit 11 includes a resistor R0, N-channel MOS transistors Q1 through Q4 connected in the diode formation, P-channel MOS transistors Q5 and Q6 used to form a current-mirror circuit, N-channel MOS transistors Q7 through Q9, and a P-channel MOS transistor Q10.
The resistor R0 and the transistors Q1 through Q4 form a series circuit provided between a Vcc (an external power supply voltage) line 22 and ground. A connection node at which the resistor R0 and the drain and gate of the transistor Q1 are connected together is connected to a terminal 23, and the gates of the transistors Q7 and Q9.
The drains of the transistors Q5 and Q6 are respectively connected to the trains of the transistors Q7 and Q8. The sources of the transistors Q7 and Q8 are commonly connected to the drain of the transistor Q9. The gate of the transistor Q10 is commonly connected to the drains of the transistors Q5 and Q7. The drain of the transistor Q10 is connected to the gate of the transistor Q8.
A burn-in voltage supply unit 12 is made up of a P-channel MOS transistor Q11 for use in switching, P-channel MOS transistors Q12, Q13 and Q14, resistors R1 and R2, and N-channel MOS transistors Q15, Q16 and Q17. The sources of the transistors Q12, Q13 and Q14 are connected to the Vcc line 22. The gate of the transistor Q15 is connected to the drain of the transistor Q12 and the source of the transistor Q11. The drain of the transistor Q15 is connected to the drain and gate of the transistor Q13. The drain of the transistor Q16 is connected to the gate of the transistor Q12 and the drain of the transistor Q14. The gate of the transistor Q16 is connected to the connection node where the resistors R1 and R2 are connected together. The drain of the transistor Q17 is connected to the sources of the transistors Q15 and Q16.
The transistors Q13 and Q14 form a current-mirror circuit. The transistor Q17 forms a constant-current source in which an output reference voltage V.sub.REF obtained at the terminal 23 is applied to the gate thereof via a terminal 24. The resistors R1 and R2 form a voltage divider.
A flat-range voltage releasing signal generating unit 13 is made up of resistors R3 and R4, P-channel MOS transistors Q18, Q19 and Q23, and N-channel MOS transistors Q20, Q21, Q22 and Q24. The resistors R3 and R4 form a voltage divider which divides the external power supply voltage Vcc. The sources of the transistors Q18, Q19 and Q23 are connected to the Vcc line 22. The sources of the transistors Q20 and Q21 are connected together. The drain of the transistor Q22 is connected to the sources of the transistors Q20 and Q21. The gate of the transistor Q24 is connected to the gates of the transistors Q20 and Q22 and a terminal 25. The transistors Q18 and Q19 connected to the drains of the transistors Q20 and Q21 form a current-mirror circuit. The gate of the transistor Q21 is connected to the node at which the resistors R3 and R4 are connected together. The gate of the transistor Q23 is connected to the drains of the transistors Q18 and Q20. Further, the drains of the transistors Q23 and Q24 are connected to the gate of the transistor Q11.
A description will now be given of the operation of the circuit with reference to FIGS. 2A through 2D, which are graphs showing the relation between the internal voltage and the external power supply voltage Vcc.
When the external power supply voltage Vcc is lower than the threshold voltages of the transistors Q1 through Q4, the transistors Q1-Q4 are OFF, and the reference voltage V.sub.REF, equal to the external power supply voltage Vcc, is output via the terminal 23. At this time, the gate potential of the transistor Q8 is balanced with the gate potential of the transistor Q7 and is equal to the external power supply voltage Vcc.
When the external power supply voltage Vcc becomes higher than a voltage Vcc1 corresponding to the threshold voltages of the transistors Q1-Q4, the transistors Q1-Q4 are turned ON, and the reference voltage V.sub.REF regulated at a constant level is output via the terminal 23. The constant reference voltage V.sub.REF is applied to the gate of the transistor Q9, which provides a constant current, and is also applied to the gate of the transistor Q7.
The current mirror circuit formed by the transistors Q5 and Q6 is formed on the drain side of the transistor Q7. Hence, the drain current equal to the drain current of the transistor Q7 flows in the transistor Q8. As a result, the gate potential of the transistor Q8 is balanced at the same potential as the gate potential V.sub.REF of the transistor Q7. Thus, as indicated by the solid line in FIG. 2A, the gate voltage V.sub.A of the transistor Q8 is constant (flat-range voltage) when the external power supply voltage Vcc is equal to or higher than a voltage Vcc1.
The voltage produced by dividing the external power supply voltage Vcc by means of the resistors R1 and R2 is applied to the gate of the transistor Q16. The above-mentioned reference voltage V.sub.REF is applied, via the terminal 24, to the gate of the transistor Q17 provided on the source side of the transistor Q16. Hence, the transistor Q17 functions as a constant-current source.
When the gate potential of the transistor Q16 is increased, the drain current thereof is increased, and the drain current of the transistor Q12 is decreased. Further, the gate potential of the transistor Q15 is increased. When the gate potential of the transistor Q15 becomes equal to the gate potential of the transistor Q16, the transistor Q12 is turned OFF. The identical currents flow in the transistors Q15 and Q16 from the current-mirror circuit of the transistors Q13 and Q14 connected to the drains of the transistors Q15 and Q16. Hence, the circuit becomes the balanced state.
Hence, as indicated by the solid line shown in FIG. 2, the gate voltage V.sub.B becomes equal to the voltage produced by dividing the voltage Vcc applied to the gate of the transistor Q16 by means of the resistors R1 and R2. Hence, the gate voltage V.sub.B is less than the external power supply voltage Vcc, and is varies in proportion to a variation in the voltage Vcc. The voltage V.sub.B is applied, as a burn-in voltage, to the source of the transistor Q11.
The output reference voltage V.sub.REF obtained at the terminal 23 is applied, via the terminal 25, to the gates of the transistors Q20 and Q22 in the flat-range voltage releasing signal generating circuit 13. Hence, the transistor Q22 functions as a current source. The external power supply voltage Vcc is divided by the resistors R3 and R4, and the divided voltage is applied to the gate of the transistor Q21. The voltage dividing ratio defined by the resistors R3 and R4 is set to a predetermined value greater than that defined by the resistors R1 and R2. Hence, the gate voltage of the transistor Q21 changes in accordance with a characteristic line less inclined than that shown in FIG. 2B.
The current-mirror circuit of the transistors Q18 and Q19 connected to the drains of the transistors Q20 and Q21 functions to make the drain currents of the transistors Q20 and Q21 equal to each other. When the gate voltage of the transistor Q21 is lower than the reference voltage V.sub.REF applied to the gate of the transistor Q20, the current flowing in the transistor Q18 becomes equal to the current flowing in the transistor Q19.
At this time, not only the current from the transistor Q18 but also the current from the transistor Q23 flow in the transistor Q20. Thus, the transistor Q23 is ON. Hence, the voltage Vc of the node at which the drains of the transistors Q23 and Q24 are connected together becomes approximately equal to the external power supply voltage Vcc applied to the source of the transistor Q23.
When the external power supply voltage Vcc is equal to a Vcc2, and the gate voltage of the transistor Q21 obtained by dividing the voltage Vcc2 becomes equal to the gate voltage V.sub.REF of the transistor Q20, the currents each equal to half the drain current of the transistor Q22 flows in the transistors Q20 and Q21. Hence, the transistor Q23 is turned OFF. Hence, the above voltage Vc becomes equal to Vss (for example, the ground level), which is the source potential of the transistor Q24 which is ON.
When the external power supply voltage Vcc is equal to or higher than the voltage Vcc2, the transistor Q23 is turned OFF in the above manner, and the voltage Vc becomes low (Vss). Hence, the voltage Vc is varied as indicated by the solid line in FIG. 2C. The voltages Vcc1 and Vcc2 are respectively set to the lower and upper limits of the external power supply voltage Vcc in the normal operation of the semiconductor device.
The voltage Vc is applied to the gate of the transistor Q11, and controls the switching thereof. More particularly, when the external power supply voltage Vcc is equal to or higher than the voltage Vcc2, a flat-range voltage releasing signal at a low level is applied to the gate of the transistor Q11 whereby it is turned ON. When the voltage Vcc is lower than the voltage Vcc2, the flat-range voltage releasing signal at a high level is applied to the gate of the transistor Q11 whereby it is turned OFF.
Hence, when the external power supply voltage Vcc is lower than Vcc2, the transistor Q11 is OFF, and the flat-range voltage V.sub.A from the flat-range voltage supply unit 11 is output to the regulator unit 14. When the external power supply voltage Vcc is equal to or greater than Vcc2, the transistor Q11 is ON, and the voltage V.sub.A is less than the voltage V.sub.B. As a result, the burn-in voltage V.sub.B from the burn-in voltage supply unit 12 is applied to the regulator unit 14 via the transistor Q11.
As a result, the input internal voltage V.sub.D applied to the regulator unit 14 is changed as a function of the external power supply voltage Vcc, as indicated by the solid line shown in FIG. 2D. It can be seen from FIG. 2D that there is the burn-in voltage on a straight line V passing through any value within the normal operation voltage range between Vcc1 and Vcc2 as well as the origin. Hence, in the burn-in test, it is possible to provide the regulator unit 14 with the burn-in voltage in the same ratio with respect to the external power supply voltage Vc as that in the normal operation. In FIG. 2D, the one-dot chained line VI indicates the characteristic of the voltage applied to the gate of the transistor Q21 from the node at which the resistors R3 and R4 are connected together.
As described above, switching between the burn-in voltage and the flat-range voltage is carried out on the basis of the level of the external power supply voltage Vcc. However, the releasing voltage Vcc2 at which the switching takes place fluctuates due to desperation in the production process or the ambient temperature. Hence there is a possibility that an erroneous voltage is applied to the internal circuits. For examples the burn-in voltage is output in the normal operation or the burn-in test cannot be performed.

Semiconductor integrated circuit device having burn-in test capability and method for using the same


A method of reducing a registration error is provided in which the registration error can be uniformly distributed even if an amount of displacement is larger than others at only one of a plurality of measuring points. According to the method, amounts of displacement are measured first at a plurality of measuring points, then one half the sum of the maximum value and the minimum value of the measured amounts of displacement is calculated to obtain a correction value. The correction value is fed back to an exposure apparatus as a correction value for an exposure condition setting file within the exposure apparatus used in an exposure step. The registration error can be distributed uniformly even if amounts of displacement at a plurality of measuring points are considerably different from each other.

1. Field of the Invention
The invention relates to a method of reducing a registration error and, more particularly to a method of reducing a registration error in an exposure step of a process for manufacturing a semiconductor device.
2. Description of the Background Art
As a pattern of a semiconductor device is miniaturized, the demand for registration accuracy in a photolithography step is increasing. For example, the design rule which refers to the minimum size in the design of a 64MDRAM (Dynamic Random Access Memory) is approximately 0.30-0.35 .mu.m. The registration accuracy required for this design rule is 0.08 .mu.m or less.
FIG. 3 is a perspective view illustrating a conventional exposure apparatus. Referring to FIG. 3, the conventional exposure apparatus is provided with a wafer 101 on a wafer stage 100 which is movable in the X-Y directions. A demagnification projection lens 103 is provided above wafer 101, and a reticle 104 with a patterned layer is placed above demagnification projection lens 103. Using the exposure apparatus of above described structure, a pattern corresponding to the pattern image of reticle 104 is formed on the surface of wafer 101. A shot 102 having one pattern which corresponds to the pattern image of reticle 104 is formed on wafer 101 by an exposure, and a plurality of shots 102 are formed on wafer 101 by repeating the exposure.
An alignment at the time of exposure by the conventional exposure apparatus is performed by moving wafer stage 100 according to an array of shots 102 in the layer pattern (not shown) formed on wafer 101 in the previous step. A general method conventionally used for recognizing the array of shots 102 is EGA (Enhanced Global Alignment). According to this EGA method, the state of placement of some of those shots 102 on wafer 101 is determined by measuring the positions of the marks for registration (alignment marks) provided in the shots 102. The array state of all the remaining shots 102 is accordingly examined. Based on the result, an alignment exposure is executed.
Conventionally, after an exposure according to EGA, an amount of displacement of shot 102 was measured by an alignment inspection device. The amount of displacement means an amount of shift (offset) in the X and Y directions as shown in FIG. 4. For measuring the amount of displacement, marks for inspection of misalignment (not shown) are first arranged in four corners of shot 102. Then, a relative amount of displacement between the first misalignment inspection marks of the first layer pattern formed in the previous step and the second misalignment inspection marks of the second resist pattern formed on the second layer on the first layer pattern is image-processed by a CCD camera, whereby the amount of displacement is calculated. An average value of the amounts of displacement at the four corners of shot 102 was conventionally used as an amount of displacement of shot 102.
If all the shots 102 are determined to be uniformly shifted in the same direction as a result of above inspection by the conventional alignment inspection device, it is understood that a correction for the offset amount was necessary beforehand in the exposure step according to EGA. That is, EGA requires a correction of the amount measured in EGA method in accordance with the positions of the marks for registration (alignment marks) or the production error of a reticle. Feeding back this correction value into an exposure condition setting file within the exposure apparatus, an offset error could be zero when the same exposure step as above will be next performed.
With reference to FIG. 5, conventional ways of calculating and feeding back a correction value will be described in the following.
Referring to FIG. 5, a first layer is formed on a semiconductor substrate (not shown) in S1 (Step 1). In S2, a first resist is applied to the first layer. Next, the applied first resist is exposed by a first exposure apparatus in S3. In S4, a first resist pattern is then formed by developing the exposed first resist. In S5, the first layer is patterned by etching using the first resist pattern thereon as a mask, thereby forming a first layer pattern. Next, a second layer is formed on the first layer pattern in S6. A second resist is then applied to the second layer in S7. In S8, the second resist is exposed by a second exposure apparatus. In S9, a second resist pattern is formed by developing the exposed second resist.
Subsequently, amounts of displacement between the first layer pattern and the second resist pattern are measured at four points (in four corners of a shot) in S10. A determination is made in S11 whether at least one of the four measured amounts of displacement is a prescribed value or more. If all the amounts of displacement are less than the prescribed value, next in S12, a second layer pattern is formed by etching the second layer using the second resist pattern thereon as a mask.
On the other hand, if at least one of the amounts of displacement is determined to be the prescribed value or more, a correction value is calculated and a second resist is formed again. The correction value is determined by firstly calculating an average value of the four measured amounts of displacement as shown in S15. Secondly the determined correction value is fed back to the second exposure apparatus in S8. After above steps, a second resist is formed again. According to the re-formation step of the second resist, the second resist pattern is first removed in S14, then the new second resist is applied again to the second layer in S7.
In the conventional method described above, if an amount of displacement between the first layer pattern and the second resist pattern is a prescribed value or more, a correction value is calculated and the value is fed back to the second exposure apparatus, then the defective second resist pattern is removed and a second resist pattern is newly formed by applying a new second resist to the second layer.
According to the conventional method for exposing a plurality of layers, in some cases an exposure apparatus (first exposure apparatus) employed for a pattern formation (first resist pattern formation) in the previous step is different from an exposure apparatus (second exposure apparatus) employed for a pattern formation (second resist pattern formation) in the following step.
Under above described condition in which a plurality of different exposure apparatuses (steppers) are alternately used, shapes of shots produced by respective exposure apparatuses may be different from each other due to the difference of lens distortion or the like between respective exposure apparatuses. FIG. 6 is a schematic illustration of an exemplary shape of a shot when different exposure apparatuses are employed for the first layer and the second layer. Referring to FIG. 6, the shape of the shot of a first layer pattern 1 is approximately rectangular, while the shape of the shot of a second resist pattern 2 is trapezoidal. As a result, when amounts of displacement between the first layer pattern 1 and the second resist pattern 2 are measured at four measuring points 3 according to S10 of FIG. 5, only an amount of displacement "a" in the X direction at the measuring point in the upper right corner is measured. This result also occurs even when a single exposure apparatus is employed, due to the change of an exposure illumination condition.
According to the conventional method of calculating a correction value shown in S15 of FIG. 5, an average value (0+0+0+a).times.1/4=a/4 of the four amounts of displacement at the four corners of the shot is computed as a correction value. The correction value is fed back to the second exposure apparatus as an offset correction value upon the next exposure. The result of an alignment inspection after the exposure by the second exposure apparatus with the correction value fed back is as shown in FIG. 7. An average value of the amounts of displacement at the four corners of the shot is (-a/4-a/4-a/4+3a/4).times.1/4=0. However, amounts of displacement at respective measuring points in the shot are -a/4, -a/4, -a/4, +3a/4, which means that there is left a point with an amount of displacement of at most 3a/4 in absolute value. If any of the amounts of displacement has such a larger value, various problems such as an electrical short, caused, for example, by a shift of a pattern of a contact hole, will occur. Such problems have become serious with the increasing miniaturization of a semiconductor pattern.

Method of reducing registration error in exposure step of semiconductor device


A restraining pen for livestock is provided for humane, safe and efficient handling of livestock. A restraining or knocking pen is provided that has features for securely receiving an animal such that the animal may be subject to knocking or veterinary operations and subsequently released from the pen without danger to the animal or human operators. A novel design provides for a compact footprint of the pen and an economical use of space.

The present invention relates generally to confining and restraining cattle and other animals. More specifically, the present invention contemplates a method and system of restraining animals to facilitate handling of the animal, as may be necessary during slaughter or veterinary operations such as inoculations, castrations and the like.
The effective restraint and handling of livestock during various operations has always presented a problem for farmers, ranchers and veterinarians. An animal must be securely restrained for the protection of the person or persons administering the procedure, hereinafter called the operator. At the same time, the restraining device must be constructed and used in a fashion that does not injure the animal.
Known restraining devices have included simple chutes, clamping head gates, vise-like body clamps, and various combinations of these features. These devices have presented many problems.
Prior efforts to combine the above features into a single system have resulted in cumbersome devices which are not easily transportable, which include a considerable array of control levers and the like, often inconveniently located on several sides of the device, typically occupy a significant amount of valuable space, and which can require multiple operators for their effective use.

System and method for restraining and handling livestock


An apparatus for variable bit rate control in moving picture compression. First, a total activity measure for the current picture to be encoded in a set of consecutive pictures is calculated. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. A statistical complexity measure is then calculated from the complexity measure of the current picture. A target bit budget is allocated to the current picture depending on the instantaneous rate, the complexity measure and the instantaneous complexity measure. After encoding the current picture, the activity-to-complexity ratio for the current picture is computed based on the total activity measure, actual bits consumed by the current picture and an average of actual quantization step sizes used to encode the current picture.

1. Field of the Invention
The invention relates to the field of data compression, and more particularly to a system capable of performing variable bit rate control for a video encoder.
2. Description of the Related Art
It is practically a cliché presently to claim that all electronic communications is engaged in a digital revolution. The main advantage of digital representation of information is the robustness of the bitstream. It can be stored and recovered, transmitted and received, processed and manipulated, all virtually without error. For example, the NTSC color video image has 29.97 frames per second, approximately 480 visible scan lines per frame, and requires approximately 480 pixels per scan line in red, green, and blue color components. However, if each color component is coded using 8 bits, the bitrate produced is ≈168 Megabits per second (Mbits/s). The raw uncompressed bitrates for various video formats are very high and are not economical in many applications.
Digital audio and video signals integrated with computers, telecommunication networks, and consumer products, are poised to fuel the information revolution. At the heart of this revolution is the digital compression of audio and video signals. Several of the compression standards involve algorithms based on a common core of compression techniques, e.g., the ITU-T (formerly CCITT) Recommendation H.261 and ITU-T Recommendation H.263, and the ISO/IEC MPEG-1, MPEG-2 and MPEG-4 standards. The MPEG algorithms were developed by the Moving Picture Experts Group (MPEG), part of a joint technical committee of the International Standards Organization (ISO) and the International Electrotechnical Commission (IEC). The MPEG committee develops standards for the multiplexed, compressed representation of video and associated audio signals. The standards specify the syntax of the compressed bitstream and the method of decoding, but leave considerable latitude for novelty and variety in the algorithm employed in the is encoder.
In MPEG, a sequence of video pictures is typically divided into a series of GOPs, where each GOP (Group of Pictures) begins with an Intra-coded picture (I-picture) followed by an arrangement of Forward Predictive-coded pictures (P-pictures) and Bidirectionally Predicted pictures (B-pictures). FIG. 1 illustrates a typical GOP in display order. I-pictures are coded without reference to preceding or upcoming pictures in the sequence. P-pictures are coded with respect to the temporally closest preceding I-picture or P-picture in the sequence. B-pictures are interspersed between the I-pictures and P-pictures in the sequence, and coded with respect to the immediately adjacent I- and P-pictures either preceding, upcoming, or both. Even though several B-pictures may occur in immediate succession, B-pictures may never be used to predict another picture.
Each picture has three components: luminance (Y), red color difference (Cr), and blue color difference (Cb). For an MPEG-2 4:2:0 format, the Cr and Cb components each have half as many samples as the Y component in both horizontal and vertical directions. As depicted in FIG. 2, the basic building block of an MPEG picture is the macroblock (MB). For 4:2:0 video, each MB consists of a 16×16 sample array of luminance samples together with one 8×8 block of samples for each of two color difference components. The 16×16 sample array of luminance samples is actually composed of four 8×8 blocks of samples.
It is the responsibility of an encoder to decide which picture coding type and which prediction mode is best. In an I-picture, each 8×8 block of pixels in a MB undergoes a discrete cosine transform (DCT) to form an 8×8 array of transform coefficients. The transform coefficients are then quantized with a quantizer matrix. The resulting quantized DCT coefficients are zig-zag scanned to form a sequence of DCT coefficients. The sequence of DCT coefficients is then encoded using a variable length code (VLC). In a P-picture, a decision is made to code each MB as an I macroblock, or to code the MB as a P macroblock. The I macroblock is encoded according to the technique described above. For each P macroblock, a prediction of the macroblock in a preceding picture is obtained. The prediction is identified by a motion vector indicating the translation between the macroblock to be coded in the current picture and its prediction in the previous picture. The predictive error between the predictive macroblock and the current macroblock is then coded using the DCT, quantization, zig-zag scanning, and VLC encoding.
In the encoding of a B-picture, a decision has to be made as to the coding of each MB. There are four macroblock modes, intra (I) mode, forward (F) mode, backward (B) mode, and interpolative forward-backward (FB) mode. I mode is intracoding using no motion compensation (as in an I macroblock). F mode is unidirectional forward predictive coding using a previous picture to obtain a motion compensated prediction (as in a P macroblock). Conversely, B mode is unidirectional backward predictive coding using a subsequent picture to obtain a motion compensated prediction. In particular, FB mode is bidirectional predictive coding, wherein a motion compensated prediction is obtained by interpolating a backward motion compensated prediction and a forward motion compensated prediction. In the cases of F, B and FB macroblock modes, the predictive error is encoded using the DCT, quantization, zig-zag scanning, and VLC encoding.
The encoder must choose quantization step sizes for an entire picture so as to control visible distortion for a given bitrate. Note that the actual bits used for encoding a picture with chosen quantization step sizes are unknown until the picture is actually coded. There is no inverse function that can determine the actual used bits of a picture by simply given desired quantization step sizes. Therefore, an important aspect of any video encoder is rate control. MPEG has an important encoder restriction, namely a limitation on the variation in bits/picture, especially in the case of constant bitrate operation. This limitation is enforced through a Video Buffer Verifier (VBV). If the VBV input data rate is the same for each picture, then the video is said to be coded at Constant Bitrate (CBR). Otherwise, the video is said to be coded at Variable Bitrate (VBR). The VBV buffer is a virtual buffer and is a model of the input buffer at the decoder. The encoder allocates bits to pictures such that VBV buffer does not overflow or underflow in the case of CBR encoding. For VBR operation, the coded bitstream enters the VBV buffer at a specified maximum bitrate until the buffer is full, when no more bits are input. This translates to a bitrate entering the VBV buffer that may be effectively variable, up to the maximum bitrate. In the case of the VBR encoding, it is only necessary to prevent VBV underflow.
The intent of VBR control is to maximize the perceptual quality of the decoded pictures while maintaining the output bitrate within permitted bounds. Unlike the CBR scheme, VBR possesses more flexibility to allocate additional bits to the pictures having complex scenery and/or high motion. Nevertheless, conventional schemes for VBR control are relatively complex, typically requiring multiple passes to accomplish video encoding. Accordingly, what is needed is a novel VBR control technique for a single-pass, real time video encoder. It is also desired to provide an apparatus for variable bit rate control in moving picture compression, which is suitable for integrated circuit implementation.

Apparatus for variable bit rate control in video compression and target bit allocator thereof


A power monitoring circuit for monitoring the power being supplied to a central processing unit (CPU) is provided. This power monitoring circuit can adaptively adjust for a suitable power level corresponding to the power rating of the CPU. The CPU on which the power monitoring circuit is used should be of the type having a factory-preset built-in power-rating code that indicates the tolerable power range acceptable by the CPU. The power monitoring circuit includes decoding means that can decode the power-rating code into a bottom-limit reference value and an bottom-limit reference value which indicate respectively the bottom and upper limits of the tolerable power range acceptable by the CPU. Further, the power monitoring circuit includes means for comparing the magnitude of the power being supplied to the CPU against the bottom-limit reference value and the bottom-limit reference value to see if the power is within the tolerable power range acceptable by the CPU. If not, a power-fault signal is generated, which can be used by a power control circuit to perform a feedback control that adjusts the power being supplied to the CPU to within the tolerable power range acceptable by the CPU. If the power control circuit is unable to adjust the power to within the tolerable power range acceptable by the CPU, an audible alarm sound is generated to notify the user or any personnel nearby to take necessary repair actions.

1. Field of the Invention
This invention relates to power monitoring circuits, and more particularly, to a power monitoring circuit for the central processing unit (CPU) on a computer circuit board that can protect the CPU from being damaged or burned out due to the power being supplied to the CPU exceeding the power rating.
2. Description of Related Art
In this information age, computers are becoming an almost indispensable tool for all walks of life. Computers are useful for various applications, such as data processing, multimedia, database, data exchange networking, to name just a few. In a computer system, such as a personal computer (PC), the core element is the central processing unit (CPU). Should the CPU fails or is damaged due to any reasons, the whole computer system may become entirely inoperative. Moreover, the CPU is typically the most expensive integrated circuit (IC) device on a PC mother board. The replacement of a damaged CPU with a good one is therefore quite costly for the user. For these reasons, the CPU on a PC mother board is usually provided with various protective means to protect it from being damaged. One factor that can cause damage to the CPU is an overly large power that exceeds the upper limit of the tolerable power range acceptable by the CPU. To prevent this, the CPU is usually provided with power monitoring means that can constantly monitor the level of the power being supplied to the CPU and make necessary adjustments in the power level or generate an alarm when an abnormal condition in the power occurs.
FIG. 1 is a schematic block diagram showing the architecture of a first conventional power monitoring circuit for monitoring the power being supplied to a CPU 10. As shown, the power monitoring circuit includes an analog-to-digital (A/D) converter 20, a digital comparator 30, an alarm signal generator 40, and a loudspeaker 50.
The A/D converter 20 has an input end coupled to the power input line of the CPU 10 to take the power being supplied to the CPU as an input, and is capable of converting the input signal into a digital signal whose value represents the current level of the power being supplied to the CPU 10. The digital comparator 30 then receives the digital output from the A/D converter 20 and compares it with a preset upper-limit reference value (which represents the tolerable upper limit of the input power to the CPU 10) and a bottom-limit reference value (which represents the tolerable bottom limit of the input power to the CPU 10). These two reference values are preset into the digital comparator 30. If the output of the A/D converter 20 is between the bottom-limit reference value and the upper-limit reference value (indicating that the current input power to the CPU 10 is within the tolerable range), the digital comparator 30 will produce no signal at its output; otherwise, if the output of the A/D converter 20 is below the bottom-limit reference value or above the upper-limit reference value (indicating that the current input power to the CPU 10 is beyond the tolerable range), the digital comparator 30 will output a power-fault signal to the alarm signal generator 40, thus triggering the alarm signal generator 40 to produce an alarm signal which is then converted by the loudspeaker 50 into an audible alarm sound to inform the user or any personnel nearby to take any necessary repair actions.
One drawback to the foregoing power monitoring circuit, however, is that the bottom-limit reference value and upper-limit reference value are fixedly preset into the digital comparator 30. For other CPUs with different power ratings, the settings to the digital comparator 30 should be manually changed, which is quite laborious to do.
FIG. 2 shows a second conventional power monitoring circuit for monitoring the power being supplied to a CPU 10. As shown, this power monitoring circuit includes a power control circuit 60 for controlling the level of the power being supplied to the CPU 10. When the CPU 10 is switched on, it will send out a power-rating code via the signal line 15 to the power control circuit 60. This power-rating code indicates the tolerable range of power that can be accepted by the CPU 10 and can set the power control circuit 60 to adjust for and supply a corresponding level of power to the CPU 10.
The foregoing power monitoring circuit, however, has the drawback that, in the event that the power control circuit 60 fails, the CPU 10 can be damaged or burned out due to the power exceeding the tolerable range and which is unknown to the user.
Most of the computer mother boards are provided with setting means that allows the user to manually set for a suitable power rating for the CPU on the mother board. However, the setting procedure is typically laborious and requires an understanding of the computer hardware. In the event that the user mistakenly set a wrong rating, the CPU could be damaged. Newer models of CPUs are factory-preset with power-rating codes that allow the power monitoring means to automatically adjust for and supply a corresponding power level to the CPU. In user, the power being supplied to the CPU can be continuously monitored by the power monitoring means. In practice, however, the power monitoring means is typically implemented with software. Therefore, in the event that the CPU malfunctions due to inadequate or over power supply, the power monitoring means may fail to function properly due to the software therein being unable to be executed by the CPU. This can cause the CPU to be damaged or burned out.

Power monitoring circuit for the central processing unit on a computer circuit board


A graphene-modified elastomer material and its preparation method. The elastomer material comprises a first component and a second component; the first component comprises isocyanate prepolymer obtained through reaction of polyol and isocyanate, and the isocyanate prepolymer has a —NCO content of 22-30%; the second component comprises the following components in parts by weight: 60-90 parts of polyetheramine, 1-10 parts of liquid amine chain extender, 1-5 parts of polytetrahydrofuran ether polyol, and 1-5 parts of graphenes. Through adjusting the —NCO content of the isocyanate prepolymer, increasing the hard segment content, and combining with the components in the second component, the invention ensures the elasticity of the polymer while improving its mechanical properties such as hardness and bending strength.

Polyurea material has high impact and wear resistance, and good anti-seepage effect, corrosion resistance and comprehensive mechanical properties. It has been widely used in national defense, civil engineering and water conservancy and hydropower projects.
Polyurea elastomer is a new type of green material developed in recent years to meet the needs of environmental protection. It is featured by rapid reaction and spray molding, and the raw material system does not contain solvent. With a fast curing speed, it can be continuously sprayed on the facade and curved surface for a thickness of more than ten millimeters without sagging.
Graphene is a two-dimensional nanomaterial composed of carbon atoms. It is a nanomaterial with high specific strength and hardness, and has a breaking strength of up to 130 GPa. In the prior art, graphene is used in combination with other materials to improve the mechanical properties of the material. However, graphene nanomaterials are easy to agglomerate at the nanometer scale, and have a poor compatibility with materials and weak interfacial bonding ability.
In view of this, this invention is specifically proposed.

Graphene-modified elastomer material and its preparation method


An aerial lift having a basket or cage having a control panel for an operator standing in the basket to maneuver the basket to a desired location, a safety switch means operable to prevent further movement of the basket in unsafe conditions, and a safety device comprising a load cell or strain gauge on the cage and an auxiliary safety switch operatively connected to the load cell via an amplifier is connected in series with the safety switch means, the auxiliary switch being operable to cut off power to the safety switch means when the sensed load on the cage exceeds a predetermined value, typically if the load strikes a stationary object.

Building construction sites for large buildings frequently employ aerial lift equipment for lifting operatives to elevated locations for, for example, the installation of overhead pipe work during the construction of a building.
A typical aerial lift may comprise a mobile self drive vehicle having an extendable boom which has an elevator basket or cage for housing operatives secured to the end of the boom. The basket may contains a control panel which permits a user standing the basket or cage to maneuver the cage to a raised location which facilitates the carrying out of work. The boom is typically raised by a powered hydraulic system on the vehicle.
It is known for the operators of such lifts to mount lengths of materials to the cages, by for example tying or lashing materials to the structure of the cage. This may give rise to dangerous situations, for example, if the length of material were to hit a stationary object such as a pillar or beam during maneuvering of the cage. Another danger could be caused by pipes or other material lengths slipping their lashings and dropping from the elevated cages.
The present invention provides a safety device and a material rack for use in an elevator cage so that the need for bad practice is reduced, increasing safety helping prevent death or serious injury in the event of the cage or materials supported on the cage hitting an abutment or other stationary object, for example a building pillar or support girder.


Paper that is uniquely suitable for use in the aseptic packaging of foods, beverages, and the like is produced via a two step sizing process comprising an internal size step and a surface size step. The internal size includes approximately 1.0% anionic rosin and about 1.3 to 2.6% alum (based on the dry pulp weight) blended to a 4.0 to 4.5 pH controlled papermachine headbox stock furnish. Following web formation and drying, the surface size is applied with a composition including about 0.025 to 0.050% alkyl ketene dimer (based on the dry pulp weight) blended with a traditional starch formulation and sufficient sodium bicarbonate to both neutralize any unreacted alum present near the surface of the internally sized web and to produce a paper having a water extractable pH level of from about 4.0 to below 6.0. Secondary web drying follows the surface size application.

Sizing is a term used in the papermaking art to describe processes which reduce the water absorbency of a paper sheet. Functionally, a sized paper sheet resists wicking by water-based ink applied to the sheet surface. Sizing also improves the dimensional stability of a sheet by inhibiting absorption of atmospheric moisture.
Sizing effectiveness in paper is measured by either or both of two standardized edge-wicking tests wherein the face surfaces of a paper sample are protected by waterproof tape and the exposed edge sample immersed in a penetrating solution for a measured time interval. Afterward, the sample is weighed and the value obtained is compared with the preimmersion sample weight to determine the quantity of solution absorbed by the sample. This absorbed quantity is then normalized by the edge area of the sample
One such edge-wicking test utilizes a 35% solution of hydrogen peroxide as the penetrating solution. The other such test subjects the sample to a 1% solution of lactic acid. Depending on the utility of the paper product, one test may be more significant than the other. For example, paper used for milk containers must have a low capacity for lactic acid edge-wicking.
Historically, sizing agents have been formulated from a mixture of about 1% per ton of dry pulp natural, anionic rosin, and about 1.5 to 2% alum (Al.sub.2 SO.sub.4).sub.3. In an acidic papermachine headbox furnish of about 4.0 to 4.5 pH, these compounds coprecipitate onto the cellulose fiber to be subsequently stabilized by drying to form a hydrophobic coating. This process of blending the size formulation with the headbox furnish is characterized as "internal sizing" due to the fact that the sizing is distributed homogeneously throughout the thickness of a paper web formed from such headbox furnish.
Although natural anionic rosin sized paper formed from an acidic headbox furnish has good hydrogen peroxide holdout, the lactic acid holdout is normally poor.
Supplemental to the internal size, paper manufactured for converted utility as a liquid or beverage container is frequently "surface sized" with a solution of glue and/or starch. In such cases, the size solution is coated onto the surface of a dry web as the web runs into a pond of the solution confined between the web surface and a roll or doctor blade surface. When applied to both web surfaces simultaneously, respective ponds are confined between opposite web surfaces and respective members of a roll nip pair. This common arrangement is characterized as a "size press."
More recently, synthetic sizing agents such as alkyl ketene dimer, stearic anhydride, and alkenyl succinic have been developed to form true chemical covalent bonds with cellulose rather than the ionic or polar bonds of natural size. Most prevalent of these synthetic size compounds is alkyl ketene dimer (AKD).
Once cured, synthetic size is more stable against water, acids, and alkalis. Consequently, synthetically sized paper has good lactic acid holdout but normally poor hydrogen peroxide holdout. The process solution of synthetic size is acid/alkali sensitive, however, and, when used as an internal size, must be blended to a substantially neutral 6.5 to 8.5 pH headbox furnish. This circumstance gives rise to the trade characterization of "neutral sizing." Synthetic size has also been used as a surface size constituent; following a synthetic or "neutral" internal size treatment, however.
Although synthetic size may be blended with cationic resins in an internal sizing process to improve hydrogen peroxide holdout, the necessary neutral pH headbox solution limits available brightness. Distinctly acid pulps are required for paper of the greatest brightness value.
It is, therefore, an object of the present invention to provide a paper sizing process by which high brightness values, low bacteriological contamination, and good holdout against hydrogen peroxide and lactic acid may be obtained.


A sound guide for a speaker is capable of guiding a sound of a desired volume to a desired position regardless of installation structure of the speaker. The sound guide for a speaker includes a speaker support for supporting the speaker in a case, and a sound guide groove formed in an inner side of the speaker support, for guiding the direction of the audible signal of the speaker at a predetermined angle. The sound propagation groove has one side coupled with the speaker and other side coupled with a sound propagation hole which is formed in the case. A handset for mobile communication using the sound guide includes a case having a speaker therein, and a sound propagation hole for propagating the audible signal generated by the speaker to outside, wherein the speaker is slanted at a predetermined angle with respect to a front side of the case. Preferably, the sound guide is mounted in an upper side of the speaker to guide the audible signal to the sound propagation hole by directing the audible signal at a predetermined angle.

1. Field of the Invention
The present invention relates to a mobile communication handset, and more particularly to a speaker installed in a handset for mobile communication.
2. Background of the Related Art
Generally, a speaker used for various electronic products converts an inaudible electrical voice signal to an audible signal. Small sized electronic products such as electronic pocket books, organizers and handsets for mobile communications (e.g., cellular phones and personal communication service (PCS) phones) require a relatively small sized overall product and a relatively large sized display, such as a liquid crystal display (LCD), to show various information to a user. To achieve this sizing, various suggestions, such as miniaturization of various components used for electronic products and variations in arrangement of the components, have been advanced.
The speaker, however, has properties such that the distance between the speaker and the ears of the user, as well as extremely fine vibrations and space structure of the speaker can vary the sound quality. For such reasons, it was difficult to reduce the size of the speaker used for small sized electronic products beyond a certain limit. It was also detrimental to change the installation position and/or structure of the speaker.
Accordingly, a related art speaker is formed in a case of the electronic product parallel and close to a sound propagation hole, which propagates an audible signal generated by the speaker to the outside. An example of the related art speaker for a handset for mobile communication will be described with reference to FIGS. 1 and 2.
Referring to FIG. 1, an LCD 20 for displaying characters is provided in a main body, i.e., a case 2 of a handset 1. A sound propagation hole 15 is formed in an upper side of the case 2, above the LCD 20, to propagate the sound generated by a speaker 10, which is provided inside the case 2. A microphone 12 and a flip 3 are provided in a lower side of the case 2.
Referring to FIG. 2, at the rear of the sound propagation hole 15 formed in a front side 2a of the case 2, the speaker 10 is provided parallel to the front side 2a of the case 2. A filter 50 is provided between the sound propagation hole 15 and the speaker 10 so as to prevent any foreign substance, such as dust, from getting into the speaker 10. The filter 50 is attached to an inner side of the case 2 by a first piece of double-sided adhesive tape 40, and attached to the speaker 10 by a second piece of double-sided adhesive tape 45.
The operation of the related art speaker for the handset will now be described. If an electrical signal reaches the handset 1, the electrical voice signal is converted to an audible signal by the speaker 10. The audible signal remains in the case 2 for a while due to resistance and then is propagated to an ear of the user through the filter 50 and the sound propagation hole 15. The filter 50 prevents any foreign substance from adhering to the speaker, and prevents deterioration of the speaker's 10 performance.
The related art handset has various problems. Recent trends in handset design have sought to reduce the handset's overall length in order to facilitate carrying and custody. By contrast, it is desirable that the size of the LCD become larger as data communication using a mobile communication system has increased. However, the extent to which the related art handset for a mobile communication can meet such requirements is limited. That is, since the related art speaker 10 is attached parallel to the front side 2a of the handset 1, the portion of the handset where the speaker 10 is mounted necessarily occupies a length greater than a diameter D of the speaker. This limits the extent to which the handset length can be reduced. Furthermore, since the speaker 10 occupies a relatively large space in the handset having a limited size, the amount of space available to the LCD 20 is reduced.
Such problems cannot be solved by simply varying the installation position and structure of the speaker. As aforementioned, since the speaker has properties that vary the sound depending on the distance between the speaker and the user's ear, as well as on the extremely fine vibration and space structure of the speaker, the volume or articulation of the sound may be deteriorated if any variation is made to only the installation position or structure of the speaker.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.

This patent is subject to a terminal disclaimer.

Sound guide for speaker and handset for mobile communication using the same


A power lifting and tilting device is more universally adaptable for economic retrofitting to most types of chairs as assists for the infirm. Little or no floor clearance requirements are achieved with power driven rollers traveling oppositely inclined surfaces of the device to produce lifting and tilting action for alighting from and occupying the chair.

The present invention relates generally to power seating assists for the infirm, and more specifically, to devices for lifting and tilting in assisting the elderly and disabled in both sitting and alighting from a chair.
Upholstered chairs with lifting/seating assists for the infirm have been commercially available for some time. Those most widely available are marketed as specialty appliances with the lifting mechanism as an integral unit built-in an upholstered chair at the time the chair is manufactured. Consequently, one in need of such an appliance frequently purchases at considerable expense a complete chair and lifting device as a unit. U.S. Pat. Nos. 3,218,102; 4,838,612 and 5,061,010 disclose representative examples of power assisted chairs with the lifting and/or tilting devices as integral units built into the chair.
While such integral power lifting/seating chairs perform quite satisfactorily, a more economic alternative is frequently needed. One such alternative would be the installation or retrofitting of a previously manufactured chair owned by the infirm with a power lifting/seating assist device. However, retrofittable chair lifting and tilting devices have had some significant disadvantages, and consequently, they have had only limited acceptance. For example, U.S. Pat. No. 4,083,599 (Gaffney) discloses a power chair lifting and tilting device with the ability of the device to lift off the floor when fully retracted. This permits an accessory base on the chair having wheels or rocker springs to engage with the floor. However, this chair lifting and tilting device includes a upper frame member which requires a hollow recess in the base of the chair. This additional clearance space is also needed to accommodate a power actuated ram for the lifting device. Hence, the chair lifting and tilting device of U.S. Pat. No. 4,083,599 is not universally adaptable to all chairs, and especially to upholstered chairs having low floor clearances.
Accordingly, it would be highly desirable to have an improved retrofittable chair lifting and tilting device, including one which would be more universally adaptable to most previously manufactured chairs, and can be easily installed without requiring structural modifications to the chair.

Retrofittable chair lifting and tilting device


A helical cam device for use with a wide variety of applications generally includes a first cam component, a second cam component and an axial guide. The cam components each have a helical cam track located on an axial end, so that coaxial alignment of the two cam components allows opposing cam tracks to contact and rotate against each other. The helical cam tracks, which are preferably divided into quadrant sections, are designed such that relative rotational movement between the cam components causes a corresponding relative axial movement. According to one embodiment, the axial guide is a cylindrical rod passing through the center of the cam components; in another embodiment, it is a cylindrical sleeve surrounding the cam components. Moreover, barrel slots, detents and/or truncated peaks can be used to control the travel of the cam components.

Cams and cam surfaces have been employed in a wide variety of applications, including hinges, valves, mechanical switches, carburetors, transmissions, metal forming machines and internal combustion engines, to name but a few. Furthermore, they have been built according to a broad range of designs. Some designs have a cam surface at an axial end of a cam component, while others have a cam surface along a portion of the longitudinal length of the cam component. In most cases, movement by a first cam component causes a resultant movement in one or more second cam components.
One example of an application using a cam device is shown in U.S. Pat. No. 3,955,241, issued May 11, 1976 to Little. This patent discloses a counterbalance hinge mechanism for a cabinet lid that includes a stationary hinge rod for rotatably supporting a pair of lid mounting cam members, and slidably supporting a pair of non-rotatable cam followers. An adjustable spring assembly serves to bias the cam followers into engagement with the cam members, in order to counterbalance gravity induced torque effects of the lid throughout a substantial portion of lid opening movement.


A hand truck includes a rectangular main frame having a hand grip attached at the upper end of the main frame and a nose attached at the lower end of the main frame. A secondary rectangular frame lies alongside the back side of the main frame, with the secondary frame being pivotally attached at its upper end to the main frame. A pair of primary wheels are attached to the lower end of the secondary frame for rolling the hand truck over a support surface such as the ground or floor. A pair of auxiliary wheels are provided on a swing away frame. The auxiliary wheels can be moved to a position in which the hand truck rests in a stable position on all four wheels. The main frame can then be pivoted about the pivotal connection to the secondary frame to be positioned in a horizontal or near horizontal position elevated from the ground or floor. Heavy objects such as kegs of beer can be rolled directly from a truck, rack or conveyor to the hand truck without requiring the operator to lift the heavy objects.

1) Field of the Invention
This invention relates generally to material handling equipment. More particularly, the present invention relates to a hand truck which allows for loading and unloading of objects thereon such as cases of beverage cans, in a manner which substantially eliminates any necessity for the operator to bend over in order to place an object onto the hand truck or to remove an object therefrom.
2) Related Prior Art
Hand trucks for transporting objects have been in use for many years. Such hand trucks are generally comprised of a nose which is fixed in an essentially perpendicular orientation to a support frame, with a set of wheels located at the lower end of the frame close to the nose. The nose is loaded with objects, either by placing objects directly thereon or by sliding the nose underneath the object. The support frame is then grasped by the operator and the wheels are temporarily immobilized while the operator rotates the support frame to lift the nose, and the objects placed thereon, until only the wheels remain on the ground. The hand truck can then be rolled by the operator to transport the objects thereon to a desired location. When it is desired to unload the hand truck the wheels are again immobilized and the nose is lowered until it rests on the ground. The operator may then remove objects directly from the hand truck, or the hand truck may be moved by sliding the nose from beneath the objects.
It has often been desirable for certain types of lifting requirements to modify the standard hand truck to make it more useful to the operator during loading and unloading thereof. Such modifications usually include a nose which is movable along the support frame in such a manner that the nose may be adjusted to a convenient position for either loading or unloading of objects thereon. A hand truck exemplary of this design is shown in U.S. Pat. No. 3,052,323 to Hopfeld which shows a hand truck having a movable nose which is adjustable along the frame by means of a chain and hydraulic pump. Other hand trucks exemplary of this concept are U.S. Pat. No. 3,907,138 Rhodes, U.S. Pat. No. 3,704,799 Morris, Jr. and U.S. Pat. No. 2,598,489 Bayer et al., which show hand trucks which have been modified to allow the nose to adjust along the frame thereof by means of a threaded screw.
In each of the prior art devices, the nose must be positioned by the operator through the operators actuation of the mechanism which moves the nose. This can become very inconvenient when the operator must load and unload a very large number of objects. Since the operator must readjust the location of the nose each time an object is loaded or unloaded from the hand truck, a very large amount of time can be expended in operating a hand truck when a very large number of objects must be loaded and unloaded. An example of this inconvenience can be illustrated in the situation where a delivery person delivering objects such as cases of beverage cans, must quickly load a hand truck with several cases of beverage cans and move them a very short distance into a store and then quickly unload them again. In this instance, a requirement for the operator to readjust the nose location in between loading and/or unloading of each individual case of beverage cans, can easily triple or quadruple the time factor involved in moving the cases of beverage cans into the store.
It is also known in the hand truck art to include an auxiliary set of wheels associated with a swing frame that is pivotally attached to the side of the main frame opposite the nose. The truck may then be set to roll on the pair of wheels located on the main frame alone or in combination with the auxiliary wheels as desired to minimize the amount of work to be expended by the handler.
Generally, the provision of the auxiliary wheels allows the hand truck to be supported on all four wheels with the main frame tilted at an acute angle with the ground or support surface. Objects can be loaded on the hand truck one on top of the other upwardly from the nose, with the objects reclining on the tilted main frame. The loaded hand truck can then be pulled or pushed using all four wheels, or the auxiliary wheels can be disengaged thereby allowing the hand truck to be moved on the two main wheels in a conventional manner.
Prior to the present disclosure, there has been no suggestion of moving the main frame of the hand truck to a horizontal or near horizontal position and of providing means for supporting the main frame in such a position elevated from the floor or support on which the wheels of the hand truck rest. In accordance with the present invention, it has been found highly desirable to provide means for positioning and supporting the main frame in a horizontal or near horizontal position elevated from the ground or floor upon which the wheels of the hand truck rest. Objects can then be moved from a rack, a truck bed or other storage area to the elevated main frame of the hand truck without undue up and down movement of the handler.
With all prior art hand trucks, the operator must bend over many times to load objects such as cases of cans or other items onto a hand truck, and then bend over again several times when unloading the cases. Heavy objects such as kegs of beer which can weigh up to 180 or more pounds are oftedn rolled off a truck, rack or conveyor system and bounced on the ground or floor. The operator must then turn the kegs upright and place one on top of the other on the hand truck. Such bending and lifting, especially when done successively hundreds of times each working day, can have serious effect on the operators health. Muscle strain, back injuries, etc. are very common for operators of this type. Such injuries may be minimized or eliminated by a hand truck in which the main frame can be positioned in a horizontal or near horizontal orientation at an optimum height above the ground or floor so as to alleviate any need for an operator to bend over to load or unload objects therefrom. When placed at an optimum height, very heavy objects such as kegs of beer can be rolled directly from the truck, storage racks, conveyors, etc. on to the hand truck without any lifting by the operator.
Further, in all prior art hand trucks utilizing auxiliary wheels, the mechanism for swinging the auxiliary wheels into and out of their operative position consists of an actuator that extends from one of the longitudinal sides of the hand truck. Such an actuator cannot be engaged by an operator who is standing at the backside of the hand truck in an operative position with his hands on the handle of the hand truck. It has been found that it is highly advantageous to provide an actuator mechanism that can be operated by the toe of the operator as the operator stands in operative position behind the hand truck with his hands on the handle of the hand truck.


A method and apparatus for providing an integrated presentation of existing media program services and secondary media program services is described. The method comprises the steps of accepting a election of a secondary media program transmitted on a secondary media program channel; accessing a mapping to determine a primary media program channel associated with the selected secondary media program channel; commanding a first tuner module to receive conditional access information associated with the primary media program channel from the primary service provider; evaluating the conditional access information to determine if a second tuner is authorized to receive the secondary media program channel; and commanding a second tuner module to receive the secondary media program if the second tuner is authorized to receive the secondary media program channel.

1. Field of the Invention
The present invention relates to systems and methods for providing program material to subscribers, and in particular to a method and system for integrating a national media program broadcast with existing regional radio broadcasts.
2. Description of the Related Art
Media programming, such as audio programs, are distributed to viewers by a variety of broadcasting methods. These methods include traditional amplitude modulated (AM) and frequency modulated (FM) analog broadcast radio, and audio channels carried by direct broadcast television providers such as DIRECTV Inc. In the near future, digital broadcast radio such as the Satellite Digital Audio Radio Service (SDARS) envisioned by XM RADIO, Inc., will also be available. When it becomes available, SDARS will provide subscribers with new, previously unavailable high quality media services, even in mobile environments like the automobile. The SDARS system uses one or more satellites to broadcast audio and advanced multimedia programs. The satellite broadcasts can be received directly by subscriber receivers at home, at business locations, or in mobile vehicles. The satellite broadcasts will also be received and retransmitted by terrestrial repeaters to provide improved coverage and availability. This technique is especially useful for mobile receivers operated in urban areas with multi-story structures, which may cause shadowing.
SDARS provides superior transmission quality and diversity of choice of programming. However, many potential customers have become accustomed to listening to media programs transmitted by their local AM and FM radio stations, and are likely to remain loyal to these media programs. This listener allegiance to existing regional AM and FM radio programming from regional service providers may slow the acceptance of SDARS. One potential solution to this problem would be to simply broadcast all regional programs to all subscribers. However, this would present a confusing array of uninteresting media programs to a typical user, and requires agreements with a multitude of rights holders and requires enormous system capacity. What is needed is a system and method for making regional broadcasts "appear" available on digital satellite broadcasts to those listeners within the reception area of the regional broadcast provider and to provide some local content to the SDARS customer via the system itself. The present invention satisfies that need.

Device and method to improve integrated presentation of existing radio services and advanced multimedia services