A vibrator for a vibratory gyroscope including a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part and a fixing part for fixing one end of the base part. The base part and bending-vibration piece are formed to extend substantially in a specified plane. At the opposite side to one end of the base part, a projection projecting from the bending-vibration piece is provided, or at least a pair of resonant arms resonating with vibration of the base part, wherein the resonant arms project from the fixing part. With this arrangement, it is possible to detect a turning angular rate with high accuracy.

1. Field of the Invention
The present invention relates to a vibrator used for an angular rate sensor used for detecting a turning angular rate in a turning system and a vibratory gyroscope using the same vibrator, and particularly to a vibrator using a piezoelectric member and a vibratory gyroscope using the same vibrator.
2. Description of the Related Art
Up to now, as an angular rate sensor used for detecting a turning angular rate in a turning system, a vibratory gyroscope using a piezoelectric member has been used for detecting position of an aircraft, a ship, a space satellite, or the like. Recently, it is used in a car-navigation system, a movement detecting mechanism of a VTR or a still camera, and the like in the field of public livelihood.
Such a vibratory gyroscope utilizes the phenomenon that when an angular speed is applied to a vibrating object, a Coriolis force is generated in the direction perpendicular to the vibratory direction. Its mechanism is analyzed by using a dynamic model (for example, xe2x80x9cHandbook of Elastic Wave Device Technologiesxe2x80x9d (Danseiha-Sosi Gijutsu Handbook) issued by Ohm, Inc., pp.491 to 497). Various kinds of piezoelectric vibratory gyroscopes have been proposed up to now. For example, a Sperry tuning-fork gyroscope, a Watson tuning-fork gyroscope, a regular-triangle prism-shaped tuning-piece gyroscope, a cylindrical tuning-piece gyroscope, and the like are known as a piezoelectric vibratory gyroscope.
The inventors are studying various applications of vibratory gyroscopes, and have studied using a vibratory gyroscope as a turning rate sensor used in a car control method of an automobile body turning rate feedback system, for example. Such a system detects the direction of a steering wheel itself by a turning angle of the steering wheel. At the same time as this, the system detects the actual turning rate of the car body by means of a vibratory gyroscope. The system finds a difference between the direction of the steering wheel and the actual body turning rate by comparing them with each other, and attains a stable body control by compensating a wheel torque and a steering angle on the basis of this difference.
However, any example of the above-mentioned former piezoelectric vibratory gyroscopes can detect a turning angular rate only by arranging a vibrator in parallel with the axis of turning (what is called a vertical arrangement). The turning axis of a turning system to be measured is usually perpendicular to the gyroscope mounting part. Accordingly, in mounting such a piezoelectric vibratory gyroscope it has been impossible to shorten the piezoelectric vibratory gyroscope in height, namely, to reduce the piezoelectric vibratory gyroscope in size in the direction of the turning axis.
In recent years, a piezoelectric vibratory gyroscope capable of detecting a turning angular rate even when arranging a vibrator perpendicularly to the turning axis (what is called a horizontal arrangement) has been proposed in a Japanese laid-open publication Tokkaihei No.8-128833. In this example, as shown as an example in FIG. 1, a vibrator extends in the directions X and Y, namely, extends perpendicularly to the turning axis Z. Each of three elastic members 51a, 51b and 51c is provided with a weight 53 at one end thereof. The elastic members 51a, 51b and 51c are vibrated by piezoelectric devices 54 and 55 in the X-Y plane in phase inverse to one another. A Coriolis force in the Y direction generated by a turning angular rate xcfx89 around the Z axis is applied to the center of gravity of the weight 53. Since the plane of the elastic members 51a, 51b and 51c and the center of gravity of the weight 53 are slightly distant in the Z direction from each other, the ends of the elastic members 51a, 51b and 51c are bent reversely to one another in the Z direction by the Coriolis forces each of which is applied to the center of gravity of the weight 53. A turning angular rate xcfx89 around the Z axis is obtained by detecting this bending vibration by means of piezoelectric devices 56 and 57.
And up to now, various configurations have been known as a vibratory gyroscope using a vibrator which is composed of plural arms and a base part joining the plural arms, gives a drive vibration in a specified plane to each of the arms, and obtains a turning angular rate on the basis of a detection vibration which is perpendicular to this drive vibration and corresponds to the applied turning angular rate. For example, a Japanese laid-open publication Tokkaihei No. 7-83671 has disclosed a vibratory gyroscope using a tuning-fork vibrator made by joining three arms composed of a middle drive arm and two detection arms at both sides of the middle drive arm in one body at the base part. FIG. 2 shows a configuration of such a former vibratory gyroscope. In the example shown in FIG. 2, a vibrator 102 forming a vibratory gyroscope is composed of three arms which are composed of a middle drive arm 104 and two detection arms 103 and 105 arranged at both sides of it nearly in parallel with it, and a base 106 at which the drive arm 104 and the detection arms 103 and 105 are joined in one body with one another.
In the above-mentioned tuning-fork vibrator 102, the drive arm 104 is vibrated in the X-Z plane by an unillustrated driving means provided on the drive arm. And the left and right detection arms 103 and 105 are resonated in the same X-Z plane. When a turning angular rate xcfx89 acts around the axis Z of symmetry of the tuning-fork vibrator 102, a Coriolis force f acts on each of the detection arms 103 and 105. Since the detection arms 103 and 105 are vibrating in the X-Z plane, vibration in the Y-Z plane is induced in the detection arms 103 and 105. A turning angular rate is measured by detecting this vibration by means of an unillustrated detecting means provided on each of the detection arms 103 and 105.
A piezoelectric vibratory gyroscope disclosed in the above-mentioned Japanese laid-open publication Tokkaihei No. 8-128833 can certainly detect a turning angular rate using the Coriolis principle even when the vibrator is arranged horizontally. However, necessity of providing the weight 53 makes it insufficient to shorten the gyroscope in height. And when the weight 53 is made thin in thickness in order to sufficiently shorten it in height, moment by a Coriolis force is made small and a bending vibration is made very small, and there is a problem that a measurement sensitivity is lowered.
And in a vibrator of a piezoelectric vibratory gyroscope having the above-mentioned configuration, the drive vibration and the detection vibration are different in the vibrating direction from each other due to configuration of the vibrator. That is to say, that vibrator needs such vibrations in two directions that the elastic members 51a, 51b and 51c which are vibrating in the X-Y plane need to vibrate also in the Z direction. Generally in a piezoelectric vibratory gyroscope, it is required to keep always a constant relation between a vibration frequency for driving and a vibration frequency for detection in order to keep a good measurement sensitivity. Now, considering a single crystal as a material for a vibrator, since a single crystal is anisotropic, variation in vibration frequency caused by a temperature change varies with the direction of vibration. Therefore, attempting to form a vibrator having the above-mentioned configuration out of a single crystal causes a problem that even in case of setting a constant relation between a drive vibration frequency and a detecting vibration frequency at a certain temperature, when the temperature is changed the relation cannot be kept and the measurement sensitivity is liable to vary with temperature.
In a former vibratory gyroscope of the above-mentioned composition shown in FIG. 2, in case of forming the vibratory gyroscope by supporting the tuning-fork vibrator 102, the vibrator 102 is supported by fixing the entire end part 107 of the base part 106 of the tuning-fork vibrator 102 opposite to the end part at which the drive arm 104 and the detection arms 103 and 105 exist, or by fixing an unillustrated supporting arm at a position of this end part 107 corresponding to the axis Z of symmetry. Therefore, it cannot be said that a Coriolis force generated by a turning angular rate is efficiently utilized for action of detection vibration in the detection arms 103 and 105, and there is a problem that sharpness of resonance (Q value) of the detection vibration in the Y-Z plane in the detection arms 103 and 105 is low and the measurement sensitivity is low.
On the other hand, as a turning angular rate detecting method, both of an ordinary vibratory gyroscope having a vertically-arranged vibrator and a vibratory gyroscope having the above-mentioned horizontally-arranged vibrator electrically take in vibration of the vibrator different in mode from a drive vibration generated by a Coriolis force as displacement of a piezoceramic member, and measures a turning angular rate on the basis of the amplitude of the output signal. However, since a vibratory gyroscope having a horizontally-arranged vibrator composed of a piezoelectric single crystal has a low sensitivity to a turning angular rate due to its composition, there is a problem that it deteriorates a detection accuracy to measure a turning angular rate on the basis of the amplitude of an output signal.
In order to solve the problem of noises caused by such external factors as a voltage fluctuation, a temperature change and the like, a technique which pays attention to a fact that a phase difference between the phase of a driving signal and the phase of an output signal is changed by a Coriolis force in a vertically-arranged tuning-piece vibrator, and measures a turning angular rate on the basis of variation of the phase difference has been disclosed in Japanese patent publication Tokkohei No. 4-14734. However, even by applying the above-mentioned detection of a turning angular rate on the basis of variation in phase difference to a vibratory gyroscope having a horizontally-arranged vibrator composed of a piezoelectric single crystal, a satisfactory result cannot be obtained in measurement sensitivity and in linearity of a phase difference to a turning angular rate.
A problem the present invention attempts to solve is to make it possible to detect a turning angular rate in a sufficiently high accuracy without providing a projection having a certain weight from a vibrator toward the axis of turning even in case of setting up the vibrator in a direction in which a vibrating arm of the vibrator extends perpendicularly to the axis of turning.
Another problem the invention attempts to solve is to provide a vibrator which can be simplified in configuration, be horizontally arranged in mounting, and be reduced in height, a method for adjusting the same vibrator, and a vibratory gyroscope using the same vibrator.
An object of the invention is to provide a vibratory gyroscope capable of measuring a turning angular rate with high sensitivity by solving the above-mentioned problems.
Another object of the invention is to provide a vibratory gyroscope using a horizontally-arranged vibrator composed of a piezoelectric single crystal, the vibratory gyroscope being improved in detection accuracy of a turning angular rate.
A vibrator according to a first embodiment of the invention comprises a main arm provided with a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part, and a fixing part for fixing one end of the base part, wherein the base part and the bending-vibration piece are formed so that they extend substantially in a specified plane.
The invention also relates to a vibratory gyroscope for detecting a turning angular rate, the vibratory gyroscope including the above discussed vibrator, an exciting means for exciting vibration of the vibrator in a plane, and a detecting means for detecting a bending vibration of the vibrator generated by a Coriolis force to be applied to the vibrator when the vibrator turns in the plane and outputting a signal according to the detected bending vibration.
Since according to the invention a drive vibration and a detection vibration of a vibrator take place in a specified plane and the invention uses a bending vibration as vibration to be detected, the invention can detect a turning angular rate with sufficiently high sensitivity without providing a projection of a certain weight from the vibrator toward the axis of turning, even when setting up the vibrator so that a vibrating arm of the vibrator extends perpendicularly to the axis of turning.
The first preferred embodiment uses a fixing piece which is fixed at both ends of it as a fixing part, and a main arm is provided at one side of this fixing piece and a resonator piece is provided at the other side of the fixing piece. The fixing piece, the main arm and the resonator piece are formed so as to extend substantially in a specified plane. That is to say, an exciting means and a bending-vibration detecting means can be disposed with a fixing piece fixed at both ends between them. Thanks to this, since such bad influences as electromechanical coupling and the like between the exciting means and the bending-vibration detecting means can be prevented, the detection accuracy is improved.
In the above-mentioned configuration, since displacement of the vibrator is in a plane, the main arm, the resonator arm, and the fixing piece can be made of the same single crystal, for example, a single crystal of quartz, LiTaO3, or LiNbO3. In this case, the measurement sensitivity can be improved. The whole of a vibrator can be made by making a single crystal thin plate and processing this single crystal thin plate by means of etching or grinding.
Although the base part and the bending-vibration piece can be made of different members from each other, it is particularly preferable that they are formed in one body. Although a material for the vibrator is not limited in particular, it is preferable to use a single crystal of quartz, LiNbO3, LiTaO3, a solid solution of lithium niobate-lithium tantalate (Li(Nb, Ta)O3, or the like. By using such a single crystal, it is possible to improve a detection sensitivity and reduce a detection noise.
And since such a single crystal is particularly insensitive to a temperature change, it is suitable for a sensor used in a car where thermal stability is necessary. This point is further described. As an angular speed sensor using a tuning-fork vibrator, there is, for example, a piezoelectric vibratory gyroscope disclosed in the above-mentioned Japanese laid-open publication Tokkaihei No. 8-128833. In such a vibrator, however, the vibrator vibrates in two directions. That is to say, in FIG. 1, the vibrator vibrates in the Z direction as well as in the X-Y plane. Therefore, particularly in case of forming the vibrator out of such a single crystal as described above, it is necessary to match the characteristics of the single crystal in the two directions with each other. In practice, however, a piezoelectric single crystal is anisotropic.
Generally in a piezoelectric vibratory gyroscope, in order to keep good sensitivity, it is required to keep a constant vibration frequency difference between a natural resonance frequency of a drive vibration mode and a natural resonance frequency of a detection vibration mode. However, a single crystal is anisotropic and a degree of variation in vibration frequency caused by a temperature change varies with the crystal face. For example, although variation in vibration frequency caused by a temperature change is very little when a single crystal is cut along a specific crystal face, variation in vibration frequency is very sensitive to a temperature change when a single crystal is cut along another crystal face.
Thus, when a vibrator vibrates in two directions, at least one of the two vibrating faces is a crystal face having a large variation in vibration frequency caused by a temperature change.
On the other hand, as shown in the invention, by making the whole of a vibrator vibrate in a specified plane and forming the vibrator out of a piezoelectric single crystal it is possible to prevent the vibrator from being influenced by anisotropy of a single crystal as described above and use only the best crystal face in characteristics of the single crystal in the vibrator.
Concretely, since every vibration of a vibrator takes place in a single plane, it is possible to manufacture a vibrator using only a crystal face having little variation in vibration frequency caused by a temperature change of a single crystal. Therefore, it is possible to provide a vibratory gyroscope having a very high thermal stability.
Among the above-mentioned single crystals, single crystals of LiNbO3, LiTaO3, and a single crystal of a solid solution of lithium niobate-lithium tantalate have particularly large electromechanical coupling coefficients. Comparing a single crystal of LiNbO3 and a single crystal of LiTaO3 with each other, the single crystal of LiTaO3 has a larger electromechanical coupling coefficient and a better thermal stability than the single crystal of LiNbO3.
A vibrator according to a second embodiment of the invention is the above-mentioned vibrator in which the main arm comprises a pair of bending-vibration pieces extending in a direction crossing the longitudinal direction of the base part and a tuning-fork vibrator piece whose tines extend respectively from the bending-vibration pieces, and the base part, the bending-vibration pieces and the tuning-fork vibrator piece are formed so as to extend substantially in a specified plane. In the above-mentioned construction, since displacement of the vibrator is in a plane, the bending vibration piece, the tuning-fork vibrator piece and the base part can be made of the same single crystal, for example, a single crystal of quartz, LiTaO3, LiNbO3, or Li(Nb, Ta)O3. This case is preferable, since the measurement sensitivity can be improved and the vibrator can be made of a single crystal thin plate by means of a wafer etching process and the like (in case of quartz) or a single crystal cutting method of grinding and the like (in case of a single crystal of LiTaO3, LiNbO3, or the like).
A vibrator adjusting method of the invention is a method for adjusting a vibrator having the above-mentioned construction, the vibrator being adjusted to a specified relation between the resonance frequency of vibration of said bending vibration piece and tuning-fork vibrator piece in said single plane and the resonance frequency of bending vibration of said base part in said single plane, by projecting both ends of said tuning-fork vibrator piece outwardly from the position of said bending vibration piece in said same single plane and reducing the length of at least one of the projected parts.
A vibratory gyroscope of this invention is a vibratory gyroscope for detecting a turning angular rate by means of a vibrator of the above-mentioned second embodiment, said vibratory gyroscope comprising an exciting means, provided in said tuning-fork vibrator piece, for exciting vibration of said tuning-fork vibrator piece, and bending vibration piece in said single plane; and a bending-vibration detecting means, provided in the base part, for detecting a bending vibration taking place in said base part in said single plane and outputting a signal according to the detected bending vibration.
And a vibratory gyroscope of this invention is a vibratory gyroscope for detecting a turning angular rate by means of a vibrator of the above-mentioned second embodiment, said vibratory gyroscope comprising an exciting means, provided in said base part, for exciting a bending movement of said base part in said single plane; and a bending-vibration detecting means, provided in the tuning-fork vibrator piece, for detecting vibration taking place in said tuning-fork vibrator piece and bending vibration piece in said single plane and outputting a signal according to the detected vibration.
A vibrator according to a third embodiment of the invention is a vibrator wherein said vibrator comprises a main arm provided with a pair of said bending-vibration pieces extending in a direction crossing the longitudinal direction of the base part and a tuning-fork vibrator piece whose tines extend respectively from the bending-vibration pieces and additionally to this main arm, a fixing piece which is fixed at both ends and at which the base part of the main arm is fixed, and a resonator piece provided on the fixing piece at a position which is at the opposite side to and corresponds to said base part, and wherein said main arm, fixing piece, and resonator piece extend in a specified plane.
It is possible to make a bending movement, having as a fulcrum the fixing piece, joined with said base part and said resonator piece take place in said base part and said resonator piece.
A vibrator adjusting method of this invention is a method for adjusting a vibrator of the third embodiment, the vibrator being adjusted to a specified relation between the resonance frequency of vibration of said tuning-fork vibrator piece and bending vibration piece in said single plane and the resonance frequency of bending vibration of said base part and said resonator piece in said single plane, by reducing length of at least one of the projected parts provided at both ends of the bending vibration pieces.
A vibratory gyroscope of this invention is a vibratory gyroscope for detecting a turning angular rate by means of a vibrator of the third embodiment, said vibratory gyroscope comprising an exciting means, provided in said tuning-fork vibrator piece, for exciting vibration of said tuning-fork vibrator piece in said single plane; and a bending-vibration detecting means, provided in the resonator piece, for detecting a bending vibration taking place in said resonator piece in said single plane and outputting a signal according to the detected bending vibration.
And a vibratory gyroscope of this invention is a vibratory gyroscope for detecting a turning angular rate by means of a vibrator of the third embodiment, said vibratory gyroscope comprising an exciting means, provided in said resonator piece, for exciting a bending movement of said resonator piece in said single plane; and a vibration detecting means, provided in the tuning-fork vibrator piece, for detecting vibration taking place in said tuning-fork vibrator piece in said single plane and outputting a signal according to the detected vibration.
In any case of the above-mentioned vibratory gyroscopes, it is possible to set an exciting means and a bending-vibration detecting means or a vibration detecting means at a position more distant from and above a vibrator in comparison with a former vibrator having no resonator piece. Accordingly, since such bad influences as electromechanical coupling and the like between the exciting means and the bending-vibration detecting means or the vibration detecting means can be prevented, the detection accuracy is improved.
A vibratory gyroscope according to a fourth embodiment of the invention is a vibratory gyroscope comprising one of said vibrators,
a driving means for driving a drive vibration,
a detecting means for detecting a vibrating state in a vibration mode which is caused by the drive vibration generated by the driving means and is different from the drive vibration, and
a phase difference detecting means for detecting a phase difference between a reference signal and an output signal, when assuming that an electrical signal used for generating a drive vibration is a reference signal and an electrical signal taken by the detecting means from a vibration having a vibration mode which is caused by the drive vibration and is different from the drive vibration;
said vibratory gyroscope detecting a turning angular rate on the basis of variation of the phase difference detected by the phase difference detecting means.
The invention has been developed by finding that in a vibratory gyroscope comprising a vibrator composed of a piezoelectric single crystal using vibration in a horizontal plane as a drive vibration, it is possible to improve detection of a turning angular rate in accuracy by obtaining a phase difference between a reference signal based on a drive vibration and an output signal based on a detection vibration, and detecting the turning angular rate on the basis of the obtained phase difference. That is to say, even in such a vibratory gyroscope as a vibratory gyroscope using a horizontally-arranged vibrator, said vibratory gyroscope being a little in vibration of the vibrator generated by a Coriolis force and low in sensitivity, it is possible to improve a gyroscopic signal to be detected in the signal-to-noise ratio of a signal to a noise caused by such external factors as a voltage fluctuation, a temperature change, and the like by using as a material for the vibrator a piezoelectric single crystal itself having a high Q value, for example, a single crystal of quartz, LiNbO3, or LiTaO3. As a result, in a range in which the amplitude of a signal called a leakage signal caused by an unnecessary vibration due to an insufficient processing accuracy or the like is 7 times larger than the amplitude of an original gyroscopic signal, it is possible to detect a turning angular rate in a range where the detection sensitivity is low but linearity of variation in phase difference to a turning angular rate is good. Therefore, the detection accuracy can be improved.
A fifth embodiment of the invention is a vibratory gyroscope having said vibrator, wherein the vibrator is a plate-shaped vibrator composed of a piezoelectric single crystal and layer-shaped parts of plural layers each of which is composed of a piezoelectric single crystal are provided between one main face and the other main face of the vibrator, and the axial directions of polarization of the respective layer-shaped parts are different from one another.
This invention relates to a vibratory gyroscope, wherein said vibrator is provided with one electrode provided on one main face and the other electrode which is provided on the other main face and is opposite to the one electrode.
This invention relates to a method for making said vibrator vibrate in a direction crossing the central face of the vibrator, said method providing one electrode on one main face, providing the other electrode opposite to the one electrode on the other main face, and applying alternating voltages different in polarity from each other, respectively, to the one electrode and the other electrode.
The invention relates to a method for detecting vibration of said vibrator, said method providing one electrode on one main face, providing the other electrode opposite to the one electrode on the other main face, connecting the one electrode and the other electrode with a voltage detecting mechanism, and detecting an alternating voltage generated between the one electrode and the other electrode by making the vibrator vibrate in a direction crossing the one main face and the other main face.
According to a vibrator and a vibratory gyroscope of the fifth embodiment, it is possible to make the vibrator perform a bending vibration in a direction crossing, preferably, perpendicular to a main face by forming electrodes on a pair of main faces of the vibrator opposite to each other and applying an alternating voltage to these electrodes. Furthermore, when a bending vibration is excited, an electric field is uniformly applied to the inside of the vibrator. Therefore, a locally ununiform electric field and an internal stress caused by the ununiform electric field are not generated inside the vibrator.
In a preferred embodiment of the invention, the respective layer-shaped parts are composed of plate-shaped members each of which is composed of a piezoelectric single crystal and which are different in the direction of polarization from one another, and these plate-shaped members are joined with one another, respectively, to form the layer-shaped parts.
And in a particularly preferred embodiment, the axial direction of polarization in one layer-shaped part of at least one main face side and the axial direction of polarization in the other layer-shaped part of the other main face side are reverse to each other.
Although a piezoelectric single crystal which is a material for the vibrator is not limited in particular, it is particularly preferable that a single crystal is quartz, lithium niobate, lithium tantalate, a solid solution of lithium niobate-lithium tantalate, langasite, or lithium tetraborate, and it is more preferable that a single crystal is lithium niobate, lithium tantalate, a solid solution of lithium niobate-lithium tantalate, or langasite. Among the above-mentioned single crystals, single crystals of quartz, LiNbO3, LiTaO3, and (Li(Nb, Ta)O3 have particularly large electromechanical coupling coefficients. Comparing a single crystal of LiNbO3 and a single crystal of LiTaO3 with each other, the single crystal of LiTaO3 has a larger electromechanical coupling coefficient and a better thermal stability than the single crystal of LiNbO3.
And it is possible to exemplify lead zirconate titanate (PZT), relaxer compounds (general expression: Pb(A1/3B2/3)O3 where A is Cd, Zn, Mg or the like, and B is Nb, Ta, W or the like), a piezoelectric single crystal of a mixed crystal system of lead zirconate titanate and a relaxer compound, langasite, and lithium tetraborate.
A vibratory gyroscope of a sixth embodiment of the invention is a vibratory gyroscope using a vibrator which is composed of plural arms and a base part for joining the plural arms with it, gives a drive vibration in a specified plane to the arms, and obtains a turning angular rate from a detection vibration corresponding to the applied angular rate of turning, said vibratory gyroscope supporting the vibrator at a small domain where there is locally a domain having the smallest detection vibration.
The invention can fix a domain where movement of the vibrator is the smallest by supporting the vibrator at a small domain where there is locally a domain having the smallest detection vibration in case of supporting the vibrator. Accordingly, since it is possible to effectively generate a detection vibration by means of a Coriolis force, a Q value of the detection vibration becomes high and the sensitivity can be improved. Since the detection vibration generated by the Coriolis force is small in amplitude, the invention is particularly effective to improve the sensitivity.
And since it increases not only the Q value of detection vibration but also the Q value of drive vibration and furthermore can improve also the sensitivity to support a vibrator at a small domain where there is locally a domain having the smallest detection vibration and a small domain where there is locally a domain having the smallest drive vibration coincide with each other, it is preferable as a preferred embodiment to support the vibrator in this way. Furthermore, it is preferable to use as a material for a vibrator a piezoelectric material such as piezoceramic or a single crystal of quartz, LiTaO3, LiNbO3, or the like, and it is more preferable in particular to use a single crystal of quartz, LiTaO3, LiNbO3, or the like. The reason is that a high Q value of a single crystal itself can be effectively used.
In the present invention, a small domain where there is locally a domain having the smallest detection vibration or the smallest drive vibration is a domain within a range where the amplitude of detection vibration or drive vibration is smaller than a thousandth of the maximum amplitude in a vibrator.
A vibratory gyroscope of a seventh embodiment of the invention is a vibratory gyroscope having a vibrator composed of an arm of a piezoelectric member, wherein said arm has a hollow part and a pair of electrodes are provided on each of the parts between which the hollow part of the arm is disposed.
In this invention, to provide a pair of electrodes on each of the parts between which the hollow part of the arm is disposed prevents an unnecessary displacement from being generated by an electric field flowing from one pair of electrodes to the other pair of electrodes, since there is no piezoelectric member at that place. Accordingly, since noises can be removed, it is possible to make a high-accuracy angular speed detection.
Although the hollow part is not limited in size in particular, it is preferable to form the hollow part equal to or longer than the electrode in the longitudinal direction of the electrode, because a leakage electric field does not cause an unnecessary displacement of the arm at all since there is no piezoelectric member to contribute the displacement. And since it is necessary to provide the hollow part correspondingly to the electrodes, it is preferable to provide the hollow part at a range of ⅓ to ⅔ arm length distant from the base of the arm in the arm of this invention which is more curved at a position closer to its base and in which each of the electrodes needs to be provided at a range of ⅓ to ⅔ arm length distant from the arm base. Furthermore, it is preferable to use a 130-degree Y plate of lithium tantalate (LiTaO3) as a piezoelectric member, since to provide the hollow part of the invention is very effective to a large influence of a leakage electric field which this invention takes as a problem.
In each of the above vibrators, its main surface may preferably have a flatness of not larger than 100 xcexcm, and an angle at the main part and the bending-vibration piece may preferably be not smaller than 45xc2x0.

Vibrator, vibratory gyroscope, and vibration adjusting method


In an approach to extending the lifespan of a flash-based storage device, responsive to receiving a signal from a storage device that the storage device is low on extra blocks, one or more free logical blocks that are no longer needed are released. The storage device is notified of the one or more free logical blocks that are no longer needed. Responsive to determining that the number of valid physical blocks is greater than the number of used logical blocks, the advertised capacity of the storage device is reduced.

The present invention relates generally to the field of computer storage, and more particularly to extending the lifespan of a flash-based storage device.
A Solid State Drive (SSD) is a type of mass storage device similar to a hard disk drive (HDD). An SSD supports reading and writing data using integrated circuit assemblies, typically flash memory devices, to store data persistently, and functioning as secondary storage in the hierarchy of computer storage. Unlike hard drives, SSDs do not have any moving parts (which is why they are called solid state drives). Since SSDs have no moving parts, they don't have to "spin up" while in a sleep state and they don't need to move a drive head to different parts of the drive to access data. Therefore, SSDs can access data faster than HDDs.
A limitation of an SSD is that flash memory has a finite number of program—erase cycles. Most commercially available flash products have a guaranteed cycle count before the wear begins to deteriorate the integrity of the storage. This effect is mitigated in some chip firmware or file system drivers by counting the writes and dynamically remapping blocks in order to spread write operations between sectors; this technique is called wear leveling. Another approach is to perform write verification and remapping to spare sectors in case of write failure, a technique called bad block management.

Extending the lifespan of a flash-based storage device

International Business Machines Corporation


According to various embodiments, a circuit arrangement is described that has a plurality of components requiring a supply. Each component requiring a supply is set up to output a signal that indicates a subsequent power requirement of the component requiring a supply. The circuit arrangement further has a control device that is set up to take the signals as a basis for ascertaining a value that represents a subsequent power requirement of the plurality of components requiring a supply, to ascertain whether the value satisfies a prescribed criterion, and to control the operation of the components requiring a supply on the basis of whether the value satisfies the prescribed criterion.

Simultaneously switching on loads, i.e. components requiring a supply, in a chip can lead to the resultant change of current causing disturbances, such as a dip in the supply voltage and malfunctions arising therefrom. This can occur, by way of example, when many loads are switched on simultaneously, e.g. when a plurality of components requiring a supply wake from a quiescent state simultaneously, when the buffer capacity of the chip is relatively small, e.g. when using production technologies that produce very small structures, when only a few supply voltage connections are existent, such as in the case of a chip card, and when a chip-internal voltage regulator cannot readjust the supply voltage quickly enough on account of its present state.
Slowly switching on the loads (e.g. activating the loads in succession) can achieve the effect that the power consumption increases more slowly. Typically, however, this also leads to reduced performance capability in comparison with simultaneously switching on the loads. A higher buffer capacity typically requires a larger surface area and a higher price for the product (e.g. for the chip or the apparatus containing the chip). Similarly, a voltage regulator that allows a faster rise in power consumption typically results in a greater surface area requirement and a higher price for the product.

Circuit arrangement and method for controlling the operation of a plurality of components requiring a supply in a circuit arrangement


The details of an apparatus and method are disclosed for setting the Uplink RRC message sequence number for a new integrity protection configuration to be applied for signalling radio bearer RB0, on completion of a UTRAN MOBILITY INFORMATION procedure. The sequence number is set to a value such that the next RRC message to be sent on uplink RB0 will use the new integrity protection configuration.

1. Technical Field
This application relates to UMTS (Universal Mobile Telecommunications System) in general, and to a method and apparatus for setting an integrity protection uplink application time for signalling bearer RB0 in a universal mobile telecommunications system in particular.
2. Description of the Related Art
UMTS is a third generation public land mobile telecommunication system. Various standardization bodies are known to publish and set standards for UMTS, each in their respective areas of competence. For instance, the 3GPP (Third Generation Partnership Project) has been known to publish and set standards for GSM (Global System for Mobile Communications) based UMTS, and the 3GPP2 (Third Generation Partnership Project 2) has been known to publish and set standards for CDMA (Code Division Multiple Access) based UMTS. Within the scope of a particular standardization body, specific partners publish and set standards in their respective areas.
Consider a wireless mobile device, generally referred to as user equipment (UE), that complies with the 3GPP specifications for the UMTS protocol. The 3GPP 25.331 specification, v.3.16.0, referred to herein as the 25.331 specification, addresses the subject of UMTS RRC (Radio Resource Control) protocol requirements between the UMTS Terrestrial Radio Access Network (UTRAN) and the UE.
Section 8.5.10 of the 25.331 specification describes integrity protection for RRC connections. The information element IE 'Integrity protection mode info' defines a new integrity protection configuration. Section 188.8.131.52.3 defines the setting of the uplink activation time for integrity protection for signalling radio bearer RB0, and is applicable for each of the SECURITY MODE COMMAND, RECONFIGURATION AND CELL UPDATE CONFIRM procedures. The activation time is the time, expressed in terms of a sequence number SN, at which a new integrity protection configuration is to be applied for signalling radio bearer RB0. In each of these cases, sections 22.214.171.124, 126.96.36.199 and 18.104.22.168 respectively state that when each procedure completes, the uplink message sequence number for radio bearer RB0 should be increased to a value such that the next RRC message to be sent on uplink RB0 will use the new integrity protection configuration.
The UTRAN MOBILITY INFORMATION procedure is a further procedure which may change the integrity protection configuration. However, the setting of the uplink message sequence number for this procedure is undefined, so that a new integrity protection configuration on RB0 may not be used for quite some time, thus compromising the security of the system.

Method and apparatus for setting an integrity protection uplink application time for signalling bearer RBO in a universal mobile telecommunications system


A linear bearing drawer slide assembly comprised of a spring damper mechanism attached to a fixed member slidingly engaged with a middle member slidingly engaged with a drawer member. The spring damper mechanism is comprised of a base connected to a guide track which includes a longitudinal channel and a pair of opposing catches. A carriage slidingly engages the guide track. A pivotal latch pivots on a column of the carriage and further includes a pair of posts that extend through the carriage to engage the pair of catches in the guide track. The base and the carriage secure a pair of springs providing a balanced closing force against a damper which reduces unwanted wear and prolongs the useable life of the drawer slide assembly.

Uncontrolled closure of a drawer can result in the problems of unwanted noise and premature wear of drawer slides, drawers and cabinetry. The art has responded generally to these problems by providing controlled closure mechanisms attached to the drawer slides. The controlled closure mechanisms often include a spring damper mechanism which cushions drawer closure, thereby reducing wear and noise. However, the controlled closure mechanisms of the prior art are cumbersome and prone to failure.
For example, U.S. Patent Application Publication No. 2004/0227438 to Tseng, et al. discloses an automatic return guiding device including a first track member having a base slidingly engaging a second track member. The base includes a sliding seat having a slot. A truck is mounted on the sliding seat and includes two pegs in the slot. A single spring is attached between the front peg of the sliding member and a rear end of the base. The truck includes an inclined face and a recessed portion. The inclined face and the recessed portion form a resilient plate on a body of the truck. A force provided by the spring produces a moment about the sliding seat. The moment is offset by the sliding seat. However, this arrangement creates premature wear on the sliding seat and other components of the device and the track members resulting in premature failure.
U.S. Pat. No. 6,736,471 to Lin discloses a buffer and return device for a slide rail in a drawer. The return device is attached to an outer rail of the drawer and includes a base, a buffer plunger and an elastic element. The base has a base chamber at a front section. The base chamber has an air passage and a lateral passage. The elastic element has one end fixed to a front end of the base chamber. A retaining plate is provided that includes a locking element moveable between a locked and an unlocked position. The retaining plate is connected to the buffer plunger and the elastic element with a lower projection passing through the bottom slot. As the drawer is closed, the buffer plunger discharges air in the base chamber to slowly close the drawer. The air passage is complicated. Further, the single elastic element produces a moment about the retaining plate which produces premature wear on the components of the device and the rails.
U.S. Pat. No. 6,953,233 to Lam, et al. discloses a cylindrical housing having two axial slots. A truck is slidable in the body with the projection extending into the second slot. The truck receives a pin attached to a guide rail of the drawer. When the drawer is opened, the pin pulls the truck along the first slot. The truck rotates and locks in the second slot. When the drawer is closed, the pin engages the first slot and rotates the truck, thus releasing the slidable body. A single spring pulls the drawer to a closed position. The single spring creates a moment which creates unnecessary wear on the components of the device and the guide rails.
U.S. Pat. No. 7,028,370 to Hoshide, et al. discloses a drawer retracting apparatus. A guiding member having two L-shaped guiding grooves is attached to a fixed portion of a cabinet member. A generally rectangular plate shaped engagement member is slidingly engaged with the guiding member by two pins in the two L-shaped guiding grooves and further connected to the guiding member by a single coil spring. A driving member attached to the moving drawer releasably engages the engaging member and the coil spring pulls the drawer member to a closed position. When opening the drawer, the engagement member slides along the guiding member until the two pins move through a generally vertically oriented section of the two guiding grooves thus releasing the driving member from engagement with the engagement member. The engagement member is locked into place until the drawer is returned. The coil spring creates an unbalanced moment force on the rectangular plate. The unbalanced force creates unnecessary wear on the engagement member and the grooves of the guiding member.
There is a need for a less expensive, less complicated, and easily installed alternative to prior art drawer slides with controlled closing mechanisms. The controlled closing mechanism disclosed provides an inexpensive yet durable and novel design which prevents unnecessary wear on drawer slides and the mechanism itself, thereby prolonging the life of components and reducing the frequency of replacement.

Soft close mechanism in a drawer slide assembly


Disclosed is a cellulose nonwoven fabric containing cellulose fibers having a maximum fiber diameter of not more than 1500 nm and a crystallinity determined by solid state NMR techniques of not less than 60%. The porosity of the cellulose nonwoven fabric is not less than 40% and not more than 99%.

As can be seen in the recent worldwide efforts directed toward nanotechnology, as a trend in the materials development, there can be mentioned one which is focused on a smaller structural unit and aims at controlling the structure. In such a technical trend, the present inventors have conducted researches on the sheet forming technology of microfibrilated cellulose (hereinafter abbreviated as MFC) obtained by using as a raw material a natural cellulose such as a pulp which contains an abundance of fibers having a thickness of 1 μm or less as disclosed in Patent Document 1 and Non-Patent Document 1 and that of a fine and highly crystalline cellulose nanofiber having a fiber diameter in a range of about several nm to 200 nm produced by acetic acid bacteria disclosed in Patent Document 2 (bacterial cellulose, hereinafter abbreviated as BC).
It has been known that a sheet comprising cellulose fibers having such minute fiber diameters has very unique material characteristics such as an extremely high mechanical strength as described in Non-Patent Document 2 and at the same time an extremely low linear expansion coefficient as disclosed in Patent Document 3 and Patent Document 4. It is described in Patent Document 3 and Patent Document 4 that a hybridized material in which spaces therebetween are filled with a resin exhibits a low linear expansion coefficient.
In addition, Patent Document 5 has recently disclosed that a hybrid film in which an epoxy resin or an acrylic resin is hybridized with a BC sheet obtained by compressing and then drying a BC gel obtained by static culture has a low linear expansion coefficient as well as high transparency, and therefore it is effective as an optical film and an optical substrate.
However, according to Patent Document 5, for example, since the BC sheet from static culture is a sheet having a very dense structure, it takes an extremely long time in the hybridization step to impregnate a cellulose fiber sheet having a porosity of about 30% with a resin monomer, which requires impregnation under reduced or increased pressure (for example, by carrying out impregnation for 12 hours under a reduced pressure of 0.08 MPa), and therefore it has been disadvantageous from a viewpoint of industrial production.
Besides, the cellulose fiber sheet mainly contributing to the realization of low linear expansion coefficient in the art disclosed by the document is intrinsically a hygroscopic material, and, accordingly it has a property to easily cause changes in physical properties when absorbing moisture. Therefore, there was a demand to reduce the fraction of BC or cellulose as much as possible in a hybrid film to a level which could maintain the feature of low linear expansion coefficient. In other words, this is a demand to increase the ratio of volume occupied by pores (porosity) to which a resin can impregnate in a cellulose nonwoven fabric.
In the meantime, as is disclosed in Patent Document 6 and Patent Document 7, the cellulose nonwoven fabrics comprising nanofibers as described above can be expected to function as a separator in an electric storage device and have high filtering properties such as those of a HEPA filter due to the fine network structure made by nanofibers. In such a field, nonwoven fabrics are required to have filter performance to intercept minute substances as well as high air permeability. In order to satisfy these requirements at the same time, a technology to control the pores of the sheet to a minute size while increasing the porosity has been needed. A technology to form a nonwoven sheet with fibers of a minute fiber diameter such as nanofibers was paid attention in Patent Document 6 and Patent Document 7 as the measures to solve the requirements.
From the viewpoint mentioned above, a technology to provide a nonwoven fabric comprising BC or fine cellulose fibers which can be a material of a matrix of hybrid film, a separator or a functional filter is expected, and the use of a static culture sheet of BC can be considered as one of the solutions thereof as described in Patent Document 5. However, when the nonwoven fabric is produced, it is desirable to conduct the production not by a batch process but by a continuous production process both from the viewpoint of industrial productivity and from the viewpoint of degree of freedom of applications of the product and therefore, the use of the static culture sheet of BC was in disadvantageous situation particularly because from the viewpoint of production process. This is because when the static culture sheets of BC are continuously produced, there arises a problem in the point of productivity due to the slow sheet forming rate (it usually needs time period of around 5 days to form sheets from a static culture gel having a sheet thickness of around 1 cm), and because there is no technology to continuously produce such a slowly produced sheet while controlling high quality. A technology to form sheets from nanofibers by an industrially applicable artificial process has been demanded.
As a technology to industrially produce nonwoven fabrics comprising nanofibers such as BC, Patent Document 7 and Patent Document 8 describe Examples of forming sheets from BC by a paper making process which is a production process of paper. Furthermore, there is disclosed in Patent Document 9 a paper making sheet forming technology of MFC corresponding to subnanofibers obtained by making fine wood pulp.
However, although these documents describe sheet forming processes of BC and MFC, they mainly emphasize only on a drying method as an important point to pay attention as compared to the case where fibers derived from pulp used for normal paper making are used and do not describe any particular point to take notice for the other steps. In fact, when relatively thin nonwoven fabrics suitable, for example, for a separator of electric storage devices are attempted to produce based on the information disclosed in these documents by performing paper making of nanofibers such as BC, it was difficult to produce high quality nonwoven fabrics having no pinhole and high uniformity stability and with high efficiency using an existing paper machine.
The uniformity referred to here means whether the distribution of sheet thickness is uniform or not at a resolution level of several mm to 10 mm at least for the sheet surface. For example, when the nonwoven fabric is used as a separator for electric storage devices mentioned above, relatively thin films having a size of about several mm as the minimum value of a slit width (in the case of tape-like form) or a diameter (in the case of a circular film) and a sheet thickness of 60 μm or less are often used. For such a use, homogeneity in physical properties (strength, air permeability, etc.) of a film by this size unit is required. Particularly when a film is a thin nonwoven fabric, the homogeneity in physical properties of the film can be approximately expressed as equivalent to the uniformity of sheet thickness. In addition, when the nonwoven fabric is used as the base material of an optical substrate mentioned above, it is natural that the optical uniformity of the substrate sheet surface is required at a high level, and for that purpose high sheet uniformity of the nonwoven fabric which was a base material was demanded.
That is, it has been necessary to solve some problems mentioned above to enable to commercially provide a nonwoven fabric comprising fine cellulose fibers as a material having the high function described above with a quality applicable to the fields in which the characteristics thereof are made good use of.
Patent Document 1: JP-A-56-100801
Patent Document 2: JP-B-6-43443
Patent Document 3: WO03/040189
Patent Document 4: JP-A-2004-270064
Patent Document 5: JP-A-2005-60680
Patent Document 6: JP-A-9-129509
Patent Document 7: J P-A-2004-204380
Patent Document 8: JP-A-10-125560
Patent Document 9: JP-A-10-140493
Non-Patent Document 1: J. Appl. Polym. Sci. Appl. Polym. Symp. 37, 797-813 (1983)
Non-Patent Document 2: 13th Polymer Materials Forum Preprints, pp. 19-20(2004)


The present invention relates to a system for connecting electrical conductors to mutually different potentials, consisting of at least two electrical terminals (10) arranged alongside one another with plug receptacles (12) and at least two plug bridges (14) which have in each case at least two plug contacts (14.2) which are connected to one another via a top web (14.1) and can be plugged into the plug receptacles (12). In order to specify a system for connecting electrical conductors to mutually different potentials in which a high degree of flexibility of the electrical connections is made possible in conjunction with a reduced space requirement, it is proposed that the plug bridges (14) and the electrical terminals (10) are embodied in a manner coordinated with one another in such a way that one plug bridge (14) can be plugged into plug receptacles (12) of the same electrical terminal (10) and the other plug bridge (14) can be plugged crosswise with respect thereto into plug receptacles (12) of two electrical terminals (10) arranged indirectly or directly alongside one another.

1. Field of the Invention
This invention relates to a system for connecting electric conductors with potentials which differ from one another that is comprised of at least two electrical terminals which are located next to one another with plug-in receptacles and at least two plug-in jumpers which each have at least two plug-in contacts which are connected to one another via a head web and which can be inserted into the plug-in receptacles.
2. Description of Related Art
A system of the type to which the present invention is directed is known, for example, from German Patent DE 43 22 535 C2. The known system for connection of electrical conductors with potentials which differ from one another is comprised of at least two electrical terminals which are located next to one another with plug-in receptacles and at least two plug-in jumpers which each have at least two plug-in contacts which are connected to one another via a head web and which can be inserted into the plug-in receptacles.
Moreover, German Patent Application DE 10 2008 017 429 A1 and the corresponding U.S. Patent Application Publication US 2010/039752 A1 disclose an electrical switchgear unit in which, to reduce the wiring cost among others, a so-called integral or coding plug is used. In order to enable flexible wiring, accordingly, different integral or coding plugs must be retained in which the individual wiring is to be implemented by contact pins which are electrically connected to one another depending on the application. For this purpose, contact bridges are plugged on one terminal side of the integral or coding plug.

System for connecting electric conductors with potentials which differ from one another and plug-in adapter for the system


The invention provides a method and apparatus for applying shipping labels over both folded or non-folded packing slips, or the like, at a single print-and-apply station, either through use of a label configured for application to a substrate and also in a superposed registered manner to another label of identical construction previously attached to the substrate, or by using a shipping label having a non-aggressive adhesive applied to a removable center section of the shipping label for attachment of the packing list, or the like, to the shipping label prior to application of the shipping label to the substrate.

When shipping a carton or other package to a recipient, it is often advantageous for the shipper to provide both a packing slip and a shipping label which can be applied to and accessed from the outside of the carton. In one commonly used approach, a packing slip is placed between the shipping label and an outside surface of the carton in such a manner that the packing slip is not visible or accessible from outside the package without tearing away a portion of the shipping label. Through the years a number of approaches have been utilized for providing such packing slip and label arrangements.
In one prior approach, shown in U.S. Pat. No. 6,186,554; 6,213,518; and RE 39,100 E, to Raming, a Duplex Carton Label/Packing List Arrangement is disclosed which utilizes duplex printers to apply printing to both sides of a form simultaneously. The need for a duplex printer and applying printing on both sides of the forms makes this approach more cumbersome and expensive than is desirable.
Another approach is shown in U.S. Pat. No. 6,616,189 B2, to Raming, for a Sequentially Placed Shipping and Packing Label System. In this approach, a packing list is applied at a first station onto a carton. A shipping label is then applied at a second station over the top of the packing list and in registry over and in surrounding relationships to the packing list. When an optional return label is used the packing list is applied over and in surrounding relationship to the return label, with each being adhered to the carton. With this arrangement, the return label, packing list, and shipping label are of different sizes increasing sequentially outward from the surface of the carton with the shipping label being the largest and the return label being the smallest. This approach suffers from several drawbacks. First, the necessity for having three different sizes of labels substantially complicates the application process and increases costs. In similar fashion, the need for sequentially applying the labels at separate stations requires a doubling or tripling of the equipment necessary to apply labels to a single carton, which increases the complexity and cost of such a system to a point that it is not practical for installation and use by many shippers.
It is also often desirable to provide a packing list having a size that is larger than a typical shipping label. For example, it is desirable to have packing lists be printed on an 8½″ by 11″ piece of paper. None of the labeling systems described above are amenable to use with larger size packing slips. In the past, it has been necessary to place such larger size packing slips inside of the carton, prior to closing the carton, or to manually insert the folded packing list into a pouch attached to an outside surface of the carton. placing the packing list inside of the carton makes verification of the items on the packing list difficult at the time the shipping label is subsequently applied. Approaches involving a plastic or paper pouch attached to the side of a carton, with the packing list being subsequently inserted into the pouch as a second step in the process of packing and preparing the carton for shipping, are labor intensive and undesirable as also adding additional cost. In addition, where a packing list must be folded prior to inserting it into a pouch the cost is increased even further.
What is needed, therefore, is an improved method and apparatus for applying shipping labels and packing slips, folded or otherwise, onto a carton or other substrate.

Method and apparatus for superposed application of shipping labels over packing slips


The present invention provides a random access procedure for establishment of a data connection between a terminal and a SA-cell in an energy-efficient network, such as e.g. a BCG2 network, wherein the total session setup time is shortened. An information request message (IRM) transmission from the mobile terminal is used for selecting the SA-cell that will serve the mobile terminal (i.e. set-up a data session with this SA-cell) and is simultaneously used for performing a ‘contention-free-like’ random-access procedure towards all candidate SA-cells. In this way performing a RACHSA procedure after selecting a SA cell becomes unnecessary, the random access time is shortened and the uplink resources (at the selected SA-cell) and the uplink transmissions from the terminal are more effectively used.

A cellular wireless access telecommunications network (system) typically includes multiple base stations, also known as, for example, base transceiver station (BTS) in GSM, NodeB in WCDMA (UMTS), and evolved NodeB or eNB in LTE. A base station includes at least transmitting and receiving equipment to support wireless communication with a (possibly mobile) terminal, in standardization more formally known as UE (User Equipment). The range that can be covered with the transmitter/receiver in a base station is limited. The area that can be served by the transmitter/receiver of a base station is referred to as its "coverage area" or as the "cell." As used herein, the term "cell" may refer to both the base station itself and to its associated coverage area.
A cell (base station) in a cellular network is typically connected to the remainder of the network via one or more backhaul links, for example, via optical fiber, via copper wire or wirelessly. A base station further includes processing capabilities, for example for the wireless transmission and reception and for handling the protocols specified between the base station and the terminal and between the base station and the network, including other cells.
In a cellular network, different cells may have different sizes, indicated e.g. as macrocells, microcells, picocells or femtocells in decreasing order of cell size. Cells may show a partial overlap with nearby cells or a smaller cell (e.g. picocell) may be entirely overlapped by a larger cell (e.g. macrocell). Multiple cells may thus form a cellular network providing near contiguous coverage in a very large area.
In a cellular network it is common that each cell (base station), when in operation, transmits broadcast signals. Such signals are known as, for example, BCH (Broadcast CHannel) in GSM, as CPICH (Common Pilot CHannel) in WCDMA (UMTS) and as RSs (Reference Signals) in LTE. The same or separate broadcast signals are used to indicate a cell's (base station's) presence and to broadcast information about the cell (system information), for example, the cell identity and information about the configuration of the cell and/or about the cell's resources, such as e.g. which channel to use in order to initiate contact with the cell. Such broadcast signals allow terminals to make measurements on the broadcast signals, e.g. to determine the strength of the signal received by the terminal, and to receive the cell's system information. The broadcast signals are usually transmitted as long as the cell is in operation. The transmit power involved in broadcasting these signals may consume up to 20% of the cell's maximum transmit power, also when the cell does not actually exchange data with a terminal in the cell or when there is no terminal at all in the cell.
In a cellular wireless network it is common to distinguish a terminal to be in an 'idle mode' or in an 'active mode'. In the active mode, the terminal is able to exchange data (e.g. sending/receiving an e-mail or making a phone call) via a cell in which the terminal is located. This requires resources in the network (e.g. frequencies and/or codes) and also requires the terminal and the network to provide power for the purpose. In the idle mode the terminal is not able to exchange data and, therefore, does not require the above resources and consumes less power. A terminal in the idle mode only regularly listens to signals broadcast by the cells and selects a 'best cell', for example the cell with the signal that the terminal receives as strongest. A terminal in the idle mode also monitors the paging channel transmitted by the selected cell for a paging message addressing the terminal. Such an (idle mode) terminal is said to 'camp on' the selected cell. When, for example because of terminal mobility, a different cell is identified as best cell, the terminal may re-select the different cell as 'best cell' and camp on the newly selected cell. It should be noted that a terminal in the idle mode normally does not inform the cell and/or the network about which cell the terminal is camping on, also not when re-selecting a different cell as best cell. When the terminal re-selects to a cell which is found to be in a different location area (LA or RA—routing area), which the terminal may determine from the cell's system information, then the terminal initiates contact with the network via the newly selected cell to perform an LA or RA update procedure, and subsequently returns to the idle mode. Thus, the network is made aware of the LA/RA the idle terminal is located in. A LA/RA commonly comprises multiple cells, as configured by the network operator. Consequently, the network is not aware on which cell an idle mode terminal is camping on, it is only aware in which LA/RA an idle terminal is (expected to be) located.
In a cellular wireless access telecommunications network a terminal and the network need to set up a session when the terminal requests a service or is being paged. This involves a terminal in the idle mode making a transition to the active mode. In an LTE network, for example, a session setup is a two-step process. If service is initiated by the network, the network performs a paging procedure, where a paging message is broadcast in all cells where the network expects the terminal to be camping on (RA/LA). When the terminal receives a paging message addressing the terminal, or if service is initiated by the terminal without having been paged, in a first step the terminal performs a random access channel (RACH) procedure towards the cell it currently is camping on to establish a Radio Resource Control (RRC) connection. When successful, in the second step, the RRC connection with that cell is used to negotiate resources for and to establish a data connection between the terminal and that cell. Then the wireless exchange of user data between the terminal and the cell is possible.
For the LTE network as well as for other legacy networks such as e.g. GSM and UMTS, all transmissions (be it signaling or data) typically occur between the terminal and a single cell which is the same cell that the terminal was camping on when it was in idle mode.
Recently, a new, more energy efficient, network architecture is being developed. One aspect in the new architecture is the use of relatively small cells. High bit rate data connections can be much more efficiently provided with a larger number of (at least partially overlapping) small cells (e.g. microcells, picocells, femtocells) than with a fewer number of larger cells (e.g. macrocells). A further aspect in the new architecture is that the power consumption of a cell is envisioned to scale, as much as possible, with the service actually provided (e.g. with the number of active terminals served, with the bit rate provided to a terminal, with the distance covered by the connection to a terminal, etc.). One approach for realizing this vision includes putting those cells that do not actually serve an active terminal into a power-save mode, e.g. switching those cells almost completely off. Another, complementary, approach includes significantly reducing or refraining from transmitting broadcast signals that are common in conventional networks. The transmission of these broadcast signals causes a large overhead, in particular for cells operating at less than full load.
The new architecture envisions distinguishing between different types of cells. A first type of cells, in this text referred to as 'SA-cell' is primarily optimized to support the wireless exchange of data with active terminals. The energy-efficiency improvements as outlined above are focused on the SA-cells. A second type of cells, in this text referred to as 'LA-cell' is primarily optimized for other functions in a cellular network, including those also found in conventional networks. Thus, it is envisioned to reduce the overhead in the system to that attributed to the LA-cells.
A LA-cell typically covers a larger area, for example comparable to that of a conventional macrocell. The LA-cells together provide near contiguous coverage in the area desired to be covered, much like in a conventional network. A LA-cell may transmit broadcast and system information, much like a conventional cell; an idle terminal may camp on a LA-cell and may also initiate a signaling connection with the LA-cell, e.g. to perform an LA/RA update or to detach from the network.
A SA-cell covers a smaller area, for example comparable to that of a conventional microcell, picocell or femtocell. The SA-cells together may support a certain bit rate in the near-contiguous area desired to be covered. An SA-cell only transmits signals when and in so far it is needed; it may be regarded to be normally 'off' or in a power-save or stand-by mode. An idle terminal also does not camp on a SA-cell. Although such a network has been referred to as a "Beyond Cellular Green Generation" (BCG2) network, this term may change in the future. Therefore, in the context of the present application, a network having such architecture will be referred to as an "energy-efficient cellular wireless network."
In an energy-efficient cellular network, if session setup is network-initiated, this is preceded by the terminal receiving a paging message via the LA-cell it is camping on. The session setup in an energy-efficient cellular network may be sub-divided into two parts. The first part includes the establishment of a signaling connection between the terminal and the LA-cell it currently is camping on, which may include a RACH procedure and RRC connection set-up, similar to legacy networks. After a signaling connection between the terminal and the LA-cell has been established, the second part includes the establishment of a data connection (data session) with an appropriate SA-cell.
Note that, in an energy-efficient network according to this architecture, it may sometimes not be possible to identify an appropriate SA-cell immediately. This may happen e.g. because all SA-cells in the vicinity of the terminal may be in a power-save mode and do not transmit a suitable signal. It may also be the case that some SA-cell is active and that the terminal detects a suitable signal from the SA-cell, but that the active SA-cell cannot optimally support the requested data session from an energy saving perspective (e.g. there is an inactive SA-cell in a better position, e.g. much closer to the terminal). It may also be the case that some SA-cell is active but that the active SA-cell cannot optimally support the requested data session from a quality of service (QoS) perspective (e.g. the active SA-cell cannot support the data session with the requested bit rate, while other inactive SA-cell(s) can).
Setting up a session in a network according to this new architecture is different from that in legacy networks. One difference is that the terminal issues a request message to a 'best LA-cell' an idle terminal is camping on but that this cell is, normally, not going to serve the terminal (i.e., the data connection for exchanging the actual user data is set up with another SA-cell). Another difference is that the SA-cell's RAT (Radio Access Technology) to support the data connection need not be the same as the LA-cell's RAT to support the terminal in idle mode, which allows optimization of one or both RATs separately for their respective primary purposes. Yet another difference is that, in the new architecture, the 'best SA-cell' to support the data connection still needs to be found. Consequently, as a part of the session setup procedure in an energy-efficient network, an appropriate cell (SA-cell) needs to be selected to support the data connection with the terminal. To ensure high quality and/or user experience, the session setup, which includes both identifying an appropriate cell and establishing a data connection with it, is preferably performed quickly.
In existing mobile radio networks, such as LTE, UMTS and GSM networks the terminal performs a random access procedure as initial step of the session set-up. The random access procedure is by default contention-based, where the UE randomly selects from a set of predetermined random access preambles and transmits the selected preamble in a random access slot (in time and/or frequency domain) of the target cell. It should be noted, however, that for LTE there is also a contention-free RACH procedure that can be used in the following time-critical procedures:
a) The terminal performs a handover between the source and the target cell. In this situation it uses a contention free (i.e. a unique) preamble for the uplink random access transmission at the target cell. This is needed to avoid collisions (i.e. more than one terminal is using the same preamble simultaneously) and speed-up the random access as the terminal is in the process of handing over from the source to the target cell.
b) The terminal has to perform uplink (UL) transmission (e.g. sending an ACK) on the uplink for cases when downlink (DL) data transfer is resumed and the uplink synchronization is lost. In order to restore the UL synchronization the terminal performs again collision-free RACH procedure (i.e. it uses a unique random access preamble) in order to speed-up the UL resynchronization as there is limited time to receive the uplink ACK for the transmitted DL data.
The LTE contention-free RACH transmission via the unique (contention-free) access preamble is implemented such that the terminal selects from the set of contention-free preambles broadcast in the system information.
In LTE there are fixed number of 64 RACH preamble signatures (in UMTS this number is not fixed) based on the Zadoff-Chu (ZC) sequence with a particular length. In UMTS the RACH preambles are based on Pseudo Noise (PN) sequences. The ZC sequences enable good detection at cell edge (i.e. low SINR conditions), reduced intra-cell interference from colliding preambles, and acceptable eNodeB receiver complexity.
The 64 RACH preambles are broadcast by the cell as part of system information including indication which portion of the preambles is reserved for contention-free RACH procedure. At mobile or network originated call the terminal randomly selects a RACH preamble (excluding those reserved for contention-free RACH) and a RACH time slot and sends it to the eNodeB. It is possible that more than one UE transmit the same preamble in the same random access slot, leading to a contention-based RACH procedure. Ideally, if there is only one terminal sending its RACH preamble in the particular RACH time slot, then the network can decode it and respond with a Random Access Response (RAR) including the timing advance, Cell Radio Network Temporary Identifier (C-RNTI) that might be definite if there is no collision, and the uplink grant for the subsequent data transmission for the terminal. Note that there is a limited time interval where the terminal expects the RAR, so if the preamble is not detected in case of collisions or bad radio conditions or too low uplink transmit power the terminal retransmits the preamble again. The terminal follows the UL grant and sends a L2/L3 message (e.g. RRC connection set-up) as instructed and includes its own unique identity. Note that in case of collision two (or more) terminals will send its L2/L3 messages on the same uplink resources with their respective identities. At the network side the eNodeB sends an early contention message, addressed to the C-RNTI and echoing the terminal identity decoded in the L2/L3 message received in the previous step. This early contention resolution message supports hybrid automatic repeat requests (HARQ), i.e. it requires ACK feedback from the UE. This ACK feedback is given only by the terminal that has correctly decoded the early contention message and recognized its own identity. Other terminals not recognizing their respective identities understand that there was a collision, transmit no HARQ feedback, quickly exit the current RACH procedure and start another one. Therefore, upon reception of the early contention resolution message the terminal has the following options: (a) the message is correctly received, own identity is detected and ACK is sent (i.e. RACH procedure is finished); (b) the message is correctly received, the identity is not recognized (i.e. contention resolution) and no feedback is sent (e.g. discontinuous transmission DTX); (c) the terminal fails to decode the message or misses the DL grant, no feedback is sent (DTX).
In some time-critical cases (e.g. handover or sending uplink ACK when DL data transfer is resumed), the eNodeB has the option to arrange contention-free access for the UE by assigning the UE a dedicated preamble via a dedicated signaling. Theoretically, it is still possible to have time collision i.e. the active terminal uses the same PRACH resource as with terminal transiting from idle to active. Note that two or more active terminals using the same PRACH resources is not expected as that would mean issuing handover (HO) command or requesting ACK of DL data at exactly the same time instant for two or more mobiles. In this case due to the different preambles and the properties of the Zadoff-Chu (ZC) preamble sequences used, it is still possible to distinct among the different terminals. Contention-free access is generally faster than contention-based access, since it does not require subsequent contention resolution process. It ends when the eNodeB sends the RAR message.
In UMTS, the available PRACH random access slots (totally 14 slots per 20 ms) are grouped into so called RACH sub-channels. Each of the RACH sub-channels is allocated to one of 8 Access Service Classes (ACSs), which denote the priority of the service for which RACH request is being made. The set of available preambles and the set of available RACH sub-channels for each ACS are provided via system information. At random access, the UE randomly select one preamble and one random access slot from the sets corresponding to the given ACS of the service. The UE also has to estimate initial power with which it is to send the selected preamble. After sending the preamble, the UE will listen to the downlink Acquisition Indicator CHannel (AICH) for the acknowledgement of the network. If a positive acknowledgement is detected, the UE transmits the random access message over the PRACH. If a negative acknowledgement is detected, the UE exits the random access procedure. If no positive or negative acknowledgement is detected, due to either collision or too-low uplink transmit power, the UE chooses the next available random access slot and randomly selects a new preamble from the sets corresponding to the given ACS. The UE also increases the transmit power by a predetermined step, and transmit the newly-selected preamble during the newly chosen random access slot.
US patent application US 2008/0261570 discloses the possibility to signal SIB7 information of UMTS in each paging message in order to provide the terminal with the random access parameters in the case of network-originated calls. The SIB7 information includes some random access parameters: Uplink Interference, Dynamic Persistence Level per Physical Random Access Channel and Expiration Time Factor. The purpose is that, in case that the random access parameters the terminal received and stored before are not valid anymore (decided by the parameter Expiration Time Factor), and therefore the terminal does not need to wait for the next transmission of the SIB7 information (typically with transmission period of 80 ms), and thus extra random access delay is avoided. No information of random access slot and preamble is signaled in the paging message.
Patent application WO 2013/037875 discloses, amongst others, user terminals transmitting an information request message (IRM) towards the plurality of the SA-cells in its surroundings. The SA-cells are connected with a (fixed or wireless) backhaul link with the overlaying LA-cell. The IRM based session set-up uses the IRM signal strength measurements at the surrounding SA-cells that are triggered and instructed by the LA-cell to receive the IRM message. The signal strength measurements at the SA-cell receiving the IRM message are reported back to the mobile terminal so the terminal can select the SA-cell or the IRM signal measurements are forwarded via the backhaul link from the receiving SA-cells towards a decision unit in the network that decides which SA-cell should serve the mobile terminal.
It is an object of the present invention to improve the random access procedure for establishment of a data connection between a terminal and a SA-cell in an energy-efficient network, such as e.g. a BCG2 network.

Session setup in an energy-efficient cellular wireless telecommunications system

Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek TNO


A method for decreasing appetite for alcohol in humans which comprises the steps of providing an effective dosage of an alpha-2-adrenergic antagonist to the subject.

Alcohol abuse and alcoholism and their consequences are considered by many Nations to be their most serious health problem. Proven methods for treating and preventing alcohol abuse and alcoholism have not been found to date. Any treatment method which ameliorated the effects of alcohol abuse and/or alcoholism would be beneficial.
Attempts have been made to develop pharmaceutical agents to treat alcohol abuse and alcoholism. For instance, the approach of using an agent which would cause nausea upon the event of alcohol consumption has been discussed and attempted. These agents, however, have not been shown to be clinically effective in well-controlled clinical trials.
Another approach has been premised on the notion that alcohol abuse and alcoholism are manifestations of anxiety and/or depression and have attempted to treat alcohol abuse or alcoholism with pharmocotherapies used in treating severe anxiety and/or depression. Generally, these treatments, and particularly antianxiety medications, have not been found to be clinically effective in well-controlled clinical trials.
Another approach is premised on the notion that specific pharmaceutical agents might modify the motivation for drinking alcohol. In effect, this approach requires a pharmaceutical agent which changes the patient's appetite for alcoholic beverages. This allows for the possibility that a subject's propensity to drink excessively can be modified even during the course of drinking. By decreasing motivation to drink, such agents would be particularly helpful in preventing relapse back into periods of excessive drinking following a period of abstinence. This approach is consistent with the observations that alcohol abuse and alcoholism tends to run in natural families (this has lead to the suggestion that alcoholism might involve specific, inheritable, neurochemistries). If this is the case, then, pharmaceutical agents may be able to effectively alter this specific neurochemistry in order to decrease the propensity to take excessive amounts of alcoholic beverages which is the essence of alcohol addictive behavior. There are events in the history of an individual that may also lead to states that might be similar to those that are characteristic of persons who inherit a risk for alcoholism. It follows that pharmaceutical agents will be useful in a variety of circumstances where the salient problem is propensity to drink alcoholic beverages extensively.
The idea that a pharmaceutical agent might be an effective therapy for alcohol abuse and alcoholism is supported by a number of recent observations. Maltrexone, for example, is an agent that reduces laboratory animal's drinking of alcoholic beverages and has recently been shown to be an effective pharmaceutical adjunct to other treatments for alcohol abuse and alcoholism. The modification of certain physiological processes, such as those associated with the renin-angiotensin system, have been shown, as another example, to modify the propensity to consume alcohol in laboratory rats. The accumulated data indicate that drugs might be useful in treating alcoholism and, further, that testing with laboratory animals is a useful means for determining what pharmaceutical agents may be useful as treatments for, or as adjuncts to other treatments for, alcohol abuse and alcoholism. Tests with animals predict what agents will be useful and will not be useful in changing or lowering the consumption of alcoholic beverages in people.
Alcohol abuse and alcoholism have been variously labelled. Some modern usage, for example, calls alcoholism alcohol dependence. What is characteristic, however, of all the conditions for which we seek better treatments is that they are characterized by excessive intake of alcoholic beverages over an extended period of time.
The inventor has found that a class of pharmaceutical agents effectively modifies the propensity of laboratory animals to consume alcohol and, therefore, constitutes a class of agents which have utility as treatments for alcohol abuse, alcoholism and/or alcohol dependence and similar conditions manifest as extensive, problematic use of alcoholic beverages. These agents are the alpha-2 adrenergic antagonists (often called alpha-2 adrenoceptor antagonists or simply alpha-2 antagonists).

Method for treating alcohol abuse and alcoholism


A tool for stripping off a jacket from tubes or cables is characterized by a bend adapted to an outer diameter of the duct or cable to be stripped, and a blade protruding from the bend to the interior of the bend. The invention provides a cost-effective, accurate and easily producible tool for stripping off a jacket from tubes or cables.

The invention is based on a priority application EP 04291397.0 which is hereby incorporated by reference.
The invention relates to a tool for stripping off a jacket from tubes or cables.
During installation of cables with an insulation jacket there is a need for stripping off the insulation jacket in order to be able to connect the surface of the conducting interior part of the cable (inner cable) to connectors or grounding couplers. Especially in the case of coaxial cables, it is important to strip off the insulation jacket entirely without damaging the outer conductor of the inner cable.
For this purpose, knives may be used. However, knives are inaccurate tools and may damage the inner cable. Several tools are available in order to circumvent this problem. However, they are complex and costly to produce.
In U.S. Pat. No. 4,127,937 a tool for cutting insulation jackets from electrical cables is described, facilitating subsequent stripping of the insulation. The cutting tool is suitable for cutting the cable both axially and circumferentially. For this purpose, the tool comprises a handle rigidly affixed to the cable and an opposed, pivotally supported blade-and-handle assembly.
EP 0 990 929 A2 describes a method and an apparatus for stripping an outer jacket from a fiber optic cable. The apparatus comprises an upper and a lower cutting surface between which the fiber optic cable is disposed. The cutting surfaces cut through the circumference of the outer jacket.

Tool for stripping off a jacket from tubes or cables


An image forming apparatus according to the present disclosure includes a fan, a first louver, and a second louver. The first louver includes first rectifier vanes that direct airflow produced by the fan. The second louver is located on an inner side of an apparatus body with respect to the first louver and faces the first louver in such a manner as to overlap the first louver in a direction of an axis of rotation of the fan. The second louver includes second rectifier vanes that direct the airflow produced by the fan. Each of the first rectifier vanes and a corresponding one of the second rectifier vanes that is adjacent thereto extend in one plane inclining at a specific angle with respect to the axis of rotation of the fan.

The present disclosure relates to image forming apparatuses such as copiers, printers, facsimiles, and multifunction peripheral each having the foregoing functions, and particularly to an image forming apparatus including louvers that direct airflow produced by a fan that cools the inside of an apparatus body.
In general, an image forming apparatus forms an image through the following process. First, the surface of an image carrier, such as a photoconductor drum, is uniformly charged by a charging device. Subsequently, an electrostatic latent image is formed on the image carrier through exposure performed by an exposure device and is visualized into a toner image by a developing device. After the toner image is transferred to a recording medium, a fixing device performs a fixing operation on the toner image. In this process, members such as a power supply board, that supplies power to the fixing device, and other devices included in the apparatus may generate a substantial amount of heat. The heat generated from these devices can increase the temperature inside the apparatus. Such heat may adversely affect image quality and lead to an apparatus failure.
To release the heat generated in the body of the image forming apparatus to the outside, the image forming apparatus may include a fan. For example, the apparatus may include a first louver located at the openable manual feed tray, and a second louver located at the housing on which the manual feed tray is positioned. The second louver faces the manual feed tray that is in a closed state. Furthermore, an exhaust fan is positioned in the housing at a position facing the second louver. Air in the housing is exhausted through the second louver by the exhaust fan. The air that has passed through the second louver is exhausted through the first louver to the outside.
In another example of an image forming apparatus, a first louver is located on an openable cover, and a second louver is located on a side cover. When the openable cover is closed, the first louver faces the second louver and an intake fan located on an apparatus body. Outside air is taken into the apparatus body by the intake fan through the first louver and the second louver and is used for cooling of a fixing device and other members.
In each of the above image forming apparatuses, the first louver and the second louver direct airflow produced by the fan. There is a large gap between the first louver and the second louver. Therefore, air from other places tends to flow into the gap between the first and second louvers. The air flowing from other places acts as a ventilation resistance to the airflow produced by the fan. If the ventilation resistance increases, the cooling effect may be reduced. To increase the cooling effect, the fan may be rotated at a high speed so that the volume of airflow is increased. However, if the fan is rotated at a high speed, problems may arise in that noise, such as the sound of the fan may increase, and the power consumption of the motor, or the like, that rotates the fan may increase. Moreover, in each of the above image forming apparatuses, since rectifier vanes of the first and second louvers extend horizontally, the noise generated by the fan travels straight to the outside of the apparatus body. Accordingly, the noise may grow louder.

Image forming apparatus including louvers for directing airflow