An objective lens (1) for an optical disk, which focuses a light beam from a light source, is designed so that a third-order coma aberration generated when the objective lens is inclined at a unit angle is larger than a third-order coma aberration generated when the optical disk (2) is inclined at the unit angle, mounted on an actuator for inclining the objective lens according to an inclination amount of the optical disk, and used. With this structure, it is possible to obtain an objective lens for an optical disk that has a large numerical aperture and is easy to manufacture and assemble, and in which the third-order coma aberration generated when the optical disk surface is inclined owing to a warp or the like can be corrected by small inclination of the objective lens, so as to reduce a residual astigmatism, which is generated according to the inclination amount, after the correction.

The present invention relates to an objective lens for an optical disk that focuses a light beam from a light source on an information recording surface of the optical disk such as a digital video disk, a digital audio disk or an optical memory disk for a computer, and an optical head device using the same.
In optical head devices for optical disks, a single lens having an aspherical surface commonly is used as an objective lens for recording information or reproducing recorded information by focusing a light beam onto a diffraction-limited spot on an information recording surface of the optical disk.
In the following, a conventional optical head device will be described, with reference to an accompanying drawing.
FIG. 7 schematically shows a configuration of the conventional optical head device. As shown in FIG. 7, a light beam emitted from a semiconductor laser 151 is subjected to a change in direction of its optical path by a beam splitter 152, and turned into substantially parallel light by a collimator lens 153. The direction of the optical path of this light beam further is changed by a mirror 154 for bending the optical path, then this light beam is focused on an information recording surface 157 of an optical disk 156 by an objective lens 155. This objective lens 155 is driven by an actuator 160. The light beam that has been focused on the information recording surface 157 of the optical disk 156 is diffracted by roughness formed on the information recording surface 157. The light beam that has been reflected and diffracted by the information recording surface 157 of the optical disk 156 passes through the objective lens 155, is subjected to the change in the direction of the optical path by the mirror 154 for bending the optical path, passes through the collimator lens 153, the beam splitter 152 and a cylindrical lens 158, and is focused on a photo detector 159. Based on an electric signal of the photo detector 159, the change in light quantity that has been modulated by the information recording surface 157 of the optical disk 156 is detected, thereby reading data on the information recording surface 157.
In the objective lens 155, a wavefront aberration may be generated because of a manufacturing error during manufacturing. This wavefront aberration theoretically can be divided into aberration components of a third-order spherical aberration, a third-order coma aberration, a third-order astigmatism and a high-order aberration.
Among these aberration components, the third-order coma aberration can be avoided by designed by forming a lens surface of the objective lens 155 to have a rotationally symmetric aspherical surface. However, in reality, decentration (displacement amount in a direction perpendicular to an optical axis) between a first surface 161 of the objective lens 155 on a parallel beam side and a second surface 162 thereof on a focusing side and tilt (inclination with respect to a surface perpendicular to the optical axis) of the first surface 161 of the objective lens 155, the second surface 162 thereof, or both surfaces are generated during manufacture and serve as predominant factors in generating the third-order coma aberration. Out of these two factors, the third-order coma aberration that is caused by the tilt is proportional to substantially the third power of NA (numerical aperture) of the objective lens 155.
In general, when a lens is inclined with respect to an optical axis, the third-order coma aberration is generated. Thus, by adjusting the angle of inclination, the generated third-order coma aberration can cancel out the third-order coma aberration due to the manufacturing error. For this purpose, the objective lens 155 of the optical head device is inclined during an assembly process of the optical head device, so as to reduce the third-order coma aberration. Such an operation is called xe2x80x9ca tilt adjustment,xe2x80x9d and this angle of inclination is called xe2x80x9ca tilt adjustment angle.xe2x80x9d
In recent years, an increasingly higher recording density has been achieved as seen in DVDs (digital video disks) or DVD-RAMs, for example. The key to achieving the densification is how small a spot can be formed on an optical disk, and it is known that the spot diameter can be reduced by increasing the numerical aperture of the lens. Accordingly, in order to achieve higher density, the numerical aperture of the lens gradually has become larger and larger, and now is 0.6 in DVDs. For a further densification, the numerical aperture has to be 0.6 or larger. Considering a manufacturing error during the manufacture of the lens or an assembly error during assembling on the optical head, lenses are designed conventionally so that the generation of decentration of the first surface and the second surface of the lens does not increase aberration and that the incidence of abaxial light does not increase aberration. In spite of a great demand, lenses with a larger numerical aperture have not been commercialized yet partly because, though it is easy to reduce only axial aberration in a lens design, it is very difficult to design a single lens having a sufficient tolerance while taking a manufacturing tolerance and an assembly tolerance into account.
Also, when the numerical aperture is raised, the third-order coma aberration that is caused by the inclination of the disk becomes larger. At present, there is a possibility that warping of the disk causes the inclination of about 0.5xc2x0, which generates the third-order coma aberration of about 70 mxcex in an optical system with a numerical aperture of 0.6 and a focal length of 3.0 mm. In order that a spot is sufficiently small and reproducible in a DVD system, the third-order coma aberration is required to be not larger than 70 mxcex. Thus, when considering the above-described third-order coma aberration generated by the inclination of the disk and the third-order coma aberration generated by the manufacturing error and the assembly error, it is impossible to record and reproduce data in this system.
When the lens having a numerical aperture of larger than 0.6 is designed by the design technique as described above, a satisfactory design is not possible because the aberration due to the decentration and the aberration due to the abaxial light generally are in an inversely proportional relationship. In other words, the lens becomes very difficult to manufacture or assemble. Also, when an optical disk is inclined with respect to an optical axis due to the warp of the disk or the like, a great deal of the third-order coma aberration is generated, so that it becomes impossible to record or reproduce data in this system.
The present invention is made in order to solve the conventional problems described above, and it is an object of the present invention to propose a new design concept for achieving a lens with a large numerical aperture and to provide an objective lens for an optical disk that has a large numerical aperture and is easy to manufacture and assemble, and an optical head device. It also is an object of the present invention to provide an objective lens for an optical disk and an optical head device that can compensate for performance deterioration due to an inclination of the disk.
In order to achieve the above-mentioned objects, the present invention has the following configuration.
An objective lens for an optical disk according to a first structure of the present invention focuses a light beam from a light source. A third-order coma aberration generated when the objective lens is inclined at a unit angle (for example, 0.5xc2x0) is larger than a third-order coma aberration generated when the optical disk is inclined at the same unit angle (for example, 0.5xc2x0). The objective lens is mounted on an actuator for inclining the objective lens according to an inclination amount of the optical disk.
With the first structure, the third-order coma aberration generated by the inclination of the optical disk can be corrected only by inclining the objective lens slightly. Also, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved. In addition, since the objective lens is mounted on the actuator and inclined according to the inclination amount of the optical disk, it is possible to provide an optical system that can suppress the generation of aberration due to a warp of the optical disk even when the warp is present.
More specifically, it is preferable that DC/LC greater than xe2x88x920.9 is satisfied, where DC (mxcex) represents a third-order coma aberration generated when the optical disk is inclined at 0.5xc2x0 and LC (mxcex) represents a third-order coma aberration generated when the objective lens is inclined at 0.5xc2x0. Furthermore, it is preferable that DC/LC greater than xe2x88x920.8 is satisfied.
Also, in the first objective lens described above, it is preferable that a numerical aperture is equal to or larger than 0.62. With this structure, a spot diameter of the light beam on the optical disk can be made smaller, achieving a high density recording of the optical disk.
Also, in the first objective lens described above, it is preferable that DC+LC is at least 10 mxcex and not larger than 40 mxcexn. The DC+LC of at least 10 mxcex allows the third-order coma aberration generated by the inclination of the optical disk to be corrected only by inclining the objective lens slightly. Also, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved. Furthermore, the DC+LC of not larger than 40 mxcex can suppress a deterioration of aberration characteristics when, because of vibration or the like, the objective lens is inclined unexpectedly. According to the above structure, excellent recording and/or reproducing become possible.
An objective lens for an optical disk according to a second structure of the present invention focuses a light beam from a light source and is used for a recordable and/or reproducible optical disk having a thickness (more precisely, a substrate thickness) of about 0.6 mm (more preferably 0.59 to 0.61 mm). A numerical aperture is at least 0.62 and not larger than 0.66. DC+LC is at least 10 mxcex, where DC (mxcex) represents a third-order coma aberration generated when the optical disk is inclined at 0.5xc2x0 and LC (mxcex) represents a third-order coma aberration generated when the objective lens is inclined at 0.5xc2x0. The objective lens is mounted on an actuator for inclining the objective lens according to an inclination amount of the optical disk. The objective lens is used in an optical system in which the objective lens is inclined so as to generate the third-order coma aberration, which cancels out the third-order coma aberration generated when the optical disk is inclined. A coefficient a is at least 30 and not larger than 35 when a relationship between X and Y is approximated by Y=aX2+bX+c, where X (xc2x0) represents an angle of inclination of the optical disk and Y (mxcex) represents an astigmatism that remains after canceling out the third-order coma aberration generated when the optical disk is inclined at X (xc2x0) by inclining the objective lens.
With the second structure, in recording and/or reproducing in a current DVD system, the third-order coma aberration generated by the inclination of the optical disk can be corrected only by inclining the objective lens slightly. Also, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved. In addition, since the objective lens is mounted on the actuator and inclined according to the inclination amount of the optical disk, it is possible to provide an optical system that can suppress the generation of aberration due to a warp of the optical disk even when the warp is present. Also, it is possible to suppress a deterioration of aberration characteristics when, because of vibration or the like, the objective lens is inclined unexpectedly. According to the above structure, excellent recording and/or reproducing become possible.
Next, an optical head device according to a first configuration of the present invention includes a light source, a collimating optical system for converting a light beam emitted from the light source into a substantially parallel light beam, an objective lens for focusing the substantially parallel light beam on an information recording surface of an optical disk, a light beam splitting member for splitting the light beam that has been modulated by the information recording surface of the optical disk, and a photo receiving member for receiving the light beam that has been modulated by the information recording surface of the optical disk. The objective lens is the first or the second objective lens described above.
With the first optical head device described above, the third-order coma aberration generated by the inclination of the optical disk can be corrected by only inclining the objective lens slightly. Also, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved. In addition, since the objective lens is mounted on the actuator and inclined according to the inclination amount of the optical disk, it is possible to suppress the generation of aberration due to a warp of the optical disk even when the warp is present. Accordingly, excellent recording and/or reproducing become possible.
In the first optical head device described above, it is preferable that the objective lens is subjected to a tilt adjustment so as to reduce a third-order coma aberration. With this configuration, since it is possible to reduce the third-order coma aberration due to errors during manufacturing lenses and assembling optical head devices by the tilt adjustment, the allowable extent of manufacturing error and assembly error is relaxed, thereby obtaining an inexpensive optical head device.
Next, an optical head device according to a second configuration of the present invention includes a light source, a collimating optical system for converting a light beam emitted from the light source into a substantially parallel light beam, an objective lens for focusing the substantially parallel light beam on an information recording surface of an optical disk, a light beam splitting member for splitting the light beam that has been modulated by the information recording surface of the optical disk, and a photo receiving member for receiving the light beam that has been modulated by the information recording surface of the optical disk. The objective lens has been subjected to a tilt adjustment so as to reduce a third-order coma aberration. A third-order coma aberration generated when the objective lens is inclined at a unit angle (for example, 0.5xc2x0) is larger than a third-order coma aberration generated when the optical disk is inclined at the unit angle (for example, 0.5xc2x0).
Furthermore, an optical head device according to a third configuration of the present invention includes a light source, a collimating optical system for converting a light beam emitted from the light source into a substantially parallel light beam, an objective lens for focusing the substantially parallel light beam on an information recording surface of an optical disk, a light beam splitting member for splitting the light beam that has been modulated by the information recording surface of the optical disk, and a photo receiving member for receiving the light beam that has been modulated by the information recording surface of the optical disk. The objective lens is subjected to a tilt adjustment so as to reduce a third-order coma aberration. DC/LC greater than xe2x88x920.9 is satisfied, where DC (mxcex) represents a third-order coma aberration generated when the optical disk is inclined at 0.5xc2x0 and LC (mxcex) represents a third-order coma aberration generated when the objective lens is inclined at 0.5xc2x0. Furthermore, it is preferable that DC/LC greater than xe2x88x920.8 is satisfied.
Moreover, an optical head device according to a fourth configuration of the present invention includes a light source, a collimating optical system for converting a light beam emitted from the light source into a substantially parallel light beam, an objective lens for focusing the substantially parallel light beam on an information recording surface of an optical disk having a thickness (more precisely, a substrate thickness) of about 0.6 mm (more preferably 0.59 to 0.61 mm), a light beam splitting member for splitting the light beam that has been modulated by the information recording surface of the optical disk, and a photo receiving member for receiving the light beam that has been modulated by the information recording surface of the optical disk. The objective lens has a numerical aperture of at least 0.62 and not larger than 0.66 and has been subjected to a tilt adjustment so as to reduce a third-order coma aberration. DC+LC is at least 10 mxcex, where DC (mxcex) represents a third-order coma aberration generated when the optical disk is inclined at 0.5xc2x0 and LC (mxcex) represents a third-order coma aberration generated when the objective lens is inclined at 0.5xc2x0. A coefficient a is at least 30 and not larger than 35 when a relationship between X and Y is approximated by Y=aX2+bX+c, where X (xc2x0) represents an angle of inclination of the optical disk and Y (mxcex) represents an astigmatism that remains after canceling out the third-order coma aberration generated when the optical disk is inclined at X (xc2x0) by inclining the objective lens.
With the second to fourth optical head devices described above, since the objective lens has been subjected to the tilt adjustment so as to reduce the third-order coma aberration, it is possible to reduce the third-order coma aberration due to errors during manufacturing lenses and assembling optical head devices. Thus, an allowable extent of a manufacturing error and an assembly error is relaxed, thereby obtaining an inexpensive optical head device.
Also, the third-order coma aberration generated by the inclination of the optical disk can be corrected by only inclining the objective lens slightly. Moreover, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved, and excellent recording and/or reproducing become possible.
In addition to the above, according to the fourth optical head device, it is possible to suppress a deterioration of aberration characteristics when, because of vibration or the like, the objective lens is inclined unexpectedly. Accordingly, excellent recording and/or reproducing become possible in a current DVD system.
Next, a method for manufacturing an optical head device according to the present invention is a method for manufacturing an optical head device including a light source, a collimating optical system for converting a light beam emitted from the light source into a substantially parallel light beam, the first or the second objective lens for focusing the substantially parallel light beam on an information recording surface of an optical disk, a light beam splitting member for splitting the light beam that has been modulated by the information recording surface of the optical disk, and a photo receiving member for receiving the light beam that has been modulated by the information recording surface of the optical disk. After the light source and the collimating optical system are placed, the objective lens is disposed while being inclined such that a coma aberration of a wavefront of the light beam from the objective lens decreases (in other words, while being subjected to the tilt adjustment).
With the above configuration, since the objective lens is disposed while being subjected to the tilt adjustment, it is possible to reduce the third-order coma aberration due to errors during manufacturing lenses and assembling optical head devices. Thus, the allowable extent of manufacturing error and assembly error is relaxed, thereby obtaining an inexpensive optical head device.
Also, by using the first or the second objective lens, the third-order coma aberration generated by the inclination of the optical disk can be corrected by only inclining the objective lens slightly. Also, since the inclination amount of the objective lens for this correction is small, the amount of astigmatism generated according to the inclination amount of the objective lens also is small. Thus, an excellent residual aberration after the correction is achieved. Moreover, since the objective lens is mounted on the actuator and inclined according to the inclination amount of the optical disk, it is possible to provide the optical system that can suppress the generation of aberration due to a warp of the optical disk even when the warp is present.
As described above, it is possible to obtain an inexpensive optical head device in which excellent recording and/or reproducing are possible.

Matsushita Electric Industrial Co., Ltd.


An inspecting tool for inspecting whether inside dimensions of a server chassis is qualified or not is presented. The inspecting tool includes a rectangular frame and a handle attached to the fame. A width of the frame is equal to a minimum desirable value of an inside width of the server chassis, and a height of the frame is equal to a minimum desirable value of an inside height of the server chassis.

1. Field of the Invention
The present invention relates to inspecting tools, and more particularly to a tool for checking whether inside dimensions of a server chassis are qualified or not.
2. Description of Related Art
A typical blade server includes a server chassis with a plurality of receiving spaces defined therein and a plurality of blades correspondingly received in the receiving rooms. Inside sizes of the receiving rooms of the server chassis may not be consistent from one chassis to another because of imprecise manufacturing, which can lead to a poor fit of the blades in the receiving rooms.
Typically, when checking whether the inside dimensions of the server chassis are qualified or not, a blade is inserted into each of the receiving rooms. However, the blade is too heavy to be manipulated conveniently. Furthermore, the blade tends to be worn out so that the accuracy of the check cannot be assured.
What is desired, therefore, is an inspecting tool that can be conveniently manipulated to check inside dimensions of a sever chassis.

Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd.


Methods of isolating spaces formed between features in an array during a pitch reduction process and semiconductor device structures having the same. In one embodiment, ends of the features are wider than middle regions of the features. During the pitch reduction process, spacer sidewalls formed between adjacent ends of the features come into substantial contact with one another, isolating the spaces between the features. In another embodiment, the features have a single width and an additional feature is located near ends of the features. Spacer sidewalls formed between adjacent features and the additional feature come into substantial contact with one another, isolating the spaces between the features.

Integrated circuit ("IC") designers desire to increase the level of integration, or density, of features within an IC by reducing the size of the features and by reducing the separation distance between neighboring features on a substrate. The distance between identical points in neighboring features is referred to in the industry as "pitch" and is conventionally measured as the center-to-center distance between the features. The pitch is about equal to the sum of a width of the feature and a width of a space separating the feature from the neighboring feature. With the pressure to reduce feature sizes and pitch, pitch reduction processes have been developed.
A conventional pitch reduction process, which is also sometimes implemented as a "pitch multiplication" process is illustrated in FIGS. 1A-1G. Pitch multiplication is used to form at least two features in a target material, such as a substrate, for each feature formed in a mask, such as a resist material, overlying the target material. As illustrated in FIG. 1A, an array of first features 10 is formed in the resist material overlying the target material 20. The first features 10 are typically formed having a minimum feature size ("F"). First features 10 are separated from each other by first spaces 12. First features 10 and first spaces 12 have a first pitch, which is labeled in FIG. 1A as "X." A spacer material 30 is formed over first features 10 and target material 20, as illustrated in FIG. 1B. The spacer material 30 reduces the width of first spaces 12, forming first spaces 12′. Spacer material 30 is anisotropically removed to form spacer sidewalls 36, as illustrated in FIGS. 1C and 1D, where FIG. 1D is a cross-sectional view along line a-a in FIG. 1C. As illustrated in FIG. 1C, which is a top view of the illustration in FIG. 1D, spacer sidewalls 36 surround each of first features 30. First features 10 are removed from target material 20, forming freestanding spacer sidewalls 36, as illustrated in FIG. 1E. The removal of first features 10 produces second spaces 18 surrounded by spacer sidewalls 36. The spacer sidewalls 36, second spaces 18, and first spaces 12′ are used as a mask to pattern the target material 20. The pattern in the target material 20 includes second features 32 (see FIG. 1G), such as lines or trenches, that correspond to second spaces 18 and first spaces 12′ and third spaces 34 (see FIG. 1G) that correspond to the spacer sidewalls 36. The second features 32 and third spaces 34 in the target material 20 have a pitch about one-half of the first pitch, which is labeled in FIG. 1E as "X/2." Where the width X included one first feature 10 and first space 12 before the pitch doubling process, width X now includes two second features 32 and two third spaces 34. While the pitch is actually halved in the example above, this reduction in pitch is conventionally referred to as pitch "doubling." This conventional terminology is retained herein.
In this pitch doubling process, ends of second spaces 18 are isolated by spacer sidewalls 36. However, ends of first spaces 12′ are not isolated. As illustrated in FIG. 1F, one approach to isolating first spaces 12′ has been to form a mask 40 over the ends of first spaces 12′, second spaces 18, and spacer sidewalls 36. Mask 40 isolates first spaces 12′, while spacer sidewalls 36 serve as a mask to pattern target material 20, as illustrated in FIG. 1G. Since a second lithography process using mask 40 is used to block an etch when forming the patterned target material 20, two masking levels are used in the pitch doubling process illustrated in FIGS. 1A-1G.
A need exists in the art for methods of isolating the second spaces formed between features without using a second masking level.

Methods of isolating array features during pitch doubling processes and semiconductor device structures having isolated array features


A flash Electrically-Erasable Programmable Read-Only Memory (EEPROM) includes a plurality of field effect transistor memory cells each having a source, drain, floating gate and control gate, and a power source for supplying a plurality of voltages to the cells. A controller controls the power source to apply at least one erase pulse to the cells. Then, at least one overerase correction or "soft programming" pulse is applied to the cells during which the source, drain and control gate voltages of the cells are such that the threshold voltages of overerased cells will be increased, but least erased cells will not be disturbed. The overerase correction pulses thereby tighten the threshold voltage distribution. A source to substrate bias voltage is applied for the duration of the overerase correction pulses which reduces the background leakage of the cells to a level at which the overerase correction operation can be effectively performed, even in applications with low supply voltages.

1. Field of the Invention
The present invention generally relates to the art of microelectronic integrated circuits, and more specifically to a method for erasing a flash Electrically Erasable Programmable Read-Only Memory (EEPROM).
2. Description of the Related Art
A microelectronic flash or block erase Electrically Erasable Programmable Read-Only Memory (Flash EEPROM) includes an array of cells which can be independently programmed and read. The size of each cell and thereby the memory are made small by omitting select transistors which would enable the cells to be erased independently. All of the cells are erased together as a block.
A memory of this type includes individual Metal-Oxide-Semiconductor (MOS) field effect transistor memory cells, each of which includes a source, drain, floating gate and control gate to which various voltages are applied to program the cell with a binary 1 or 0, or erase all of the cells as a block.
The cells are connected in a rectangular array of rows and columns, with the control gates of the cells in a row being connected to a respective wordline and the drains of the cells in a column being connected to a respective bitline. The sources of the cells are connected together. This arrangement is known as a NOR memory configuration.
A cell is programmed by applying, typically, 9 V to the control gate, 5 V to the drain and grounding the source, which causes hot electrons to be injected from the drain depletion region into the floating gate. Upon removal of the programming voltages, the injected electrons are trapped in the floating gate and create a negative charge therein which increases the threshold voltage of the cell to a value in excess of approximately 4 V.
The cell is read by applying typically 5 V to the control gate, 1 V to the bitline to which the drain is connected, grounding the source, and sensing the bitline current. If the cell is programmed and the threshold voltage is relatively high (4 V), the bitline current will be zero or at least relatively low. If the cell is not programmed or erased, the threshold voltage will be relatively low (2 V), the control gate voltage will enhance the channel, and the bitline current will be relatively high.
A cell can be erased in several ways. In one arrangement, a cell is erased by applying typically 12 V to the source, grounding the control gate and allowing the drain to float. This causes the electrons which were injected into the floating gate during programming to be removed by Fowler-Nordheim tunneling from the floating gate through the thin tunnel oxide layer to the source. Alternatively, a cell can be erased by applying a negative voltage on the order of -10 V to the control gate, applying 5 V to the source and allowing the drain to float.
A problem with the conventional flash EEPROM cell arrangement is that due to manufacturing tolerances, some cells become over-erased before other cells become erased sufficiently. The floating gates of the over-erased cells are depleted of electrons and become positively charged. This causes the over-erased cells to function as depletion mode transistors which cannot be turned off by normal operating voltages applied to their control gates, and introduces leakage during subsequent program and read operations.
More specifically, during program and read operations only one wordline which is connected to the control gates of a row of cells is held high at a time, while the other wordlines are grounded. However, a positive voltage is applied to the drains of all of the cells. If the threshold voltage of an unselected cell is zero or negative, leakage current will flow through the source, channel and drain of the cell.
This undesirable effect is illustrated in FIG. 1. The drains of a column of floating gate cell transistors T.sub.0 to T.sub.m are connected to a bitline BL, which is iteslf connected to a bitline driver 1. The sources of the transistors T.sub.0 to T.sub.m are typically connected to ground. One of the transistors T.sub.0 to T.sub.m is selected for a program or read operation by applying a positive voltage, e.g. 5 V, to its control gate which turns on the transistor. The control gates of the unselected tranistors are connected to ground.
As viewed in FIG. 1, 5 V is applied to the transistor T.sub.1 which turns it on. A curent I.sub.1 flows through the transistor T.sub.1 from ground through its source, channel (not shown) and drain and through the bitline BL to the driver 1. Ideally, the bitline current I.sub.BL should be equal to I.sub.1.
However, if one or more of the unselected transistors, e.g. the transistor T.sub.2 as illustrated in FIG. 1, is overerased, its threshold voltage will be zero or negative, and background leakage current will flow through the transistor T.sub.2 as indicated at I.sub.2. The bitline current I.sub.BL is now no longer equal to I.sub.1, but is equal to the sum of I.sub.1 and the background leakage current I.sub.2.
In a typical flash EEPROM, the drains of a large number, for example 512, transistor cells such as illustrated in FIG. 1 are connected to each bitline (column). If a substantial number of cells on the bitline are drawing background leakage current, the total leakage current on the bitline can exceed the cell read current. This makes it impossible to read the state of a cell on the bitline and renders the memory inoperative.
FIG. 2 illustrates how the threshold voltages of the cells or bits in a flash EEPROM can differ substantially from each other following an erase operation as shown by a solid line curve which represents the numbers of cells having particular values of threshold voltage V.sub.T. It will be seen that the least erased cells will have a relatively high threshold voltage V.sub.T MAX, whereas the most overerased cells will have a low threshold voltage which is below a minimum acceptable value V.sub.T MIN that can be negative. The characteristic illustrated in FIG. 2 is known as the threshold voltage distribution.
FIG. 3 illustrates how the background leakage current of a cell varies as a function of threshold voltage. The lower (more negative) the threshold voltage, the higher the leakage current. It is therefore desirable to prevent cells from being overerased and reduce the threshold voltage distribution to as low a range as possible, with ideally all cells having the same high threshold voltage after erase on the order of 2 V.
It is known in the art to reduce the threshold voltage distribution by performing an overerase correction operation which reprograms the most overerased cells to a higher threshold voltage. This operation will result in the threshold voltage curve being altered to the shape indicated by broken line in FIG. 2 in which the threshold voltages of all of the cells are above the minimum acceptable value V.sub.T MIN. An overerase correction operation of this type is generally known as Automatic Programming Disturb (APD).
A preferred APD method which is referred to as Automatic Programming Disturb Erase (APDE) is disclosed in U.S. Pat. No. 5,642,311, entitled "OVERERASE CORRECTION FOR FLASH MEMORY WHICH LIMITS OVERERASE AND PREVENTS ERASE VERIFY ERRORS", issued Jun. 24, 1997 to Lee Cleveland. This patent is assigned to the same assignee as the present invention and is incorporated herein by reference in its entirety. The method includes sensing for overerased cells and applying programming pulses thereto which bring their threshold voltages back up to acceptable values.
Following application of an erase pulse, undererase correction is first performed on a cell-by cell basis by rows. The cell in the first row and column position is addressed and erase verified by applying 4 V to the control gate (wordline), 1 V to the drain (bitline), grounding the source, and using sense amplifiers to sense the bitline current and thereby determine if the threshold voltage of the cell is above a value of, for example, 2 V. If the cell is undererased (threshold voltage above 2 V), the bitline current will be low. In this case, an erase pulse is applied to all of the cells, and the first cell is erase verified again.
After application of each erase pulse and prior to a subsequent erase verify operation, overerase correction is performed on all of the cells of the memory. Overerase verify is performed on the bitlines of the array in sequence. This is accomplished by grounding the wordlines, applying typically 1 V to address the first bitline, and sensing the bitline current. If the current is above a predetermined value, this indicates that at least one of the cells connected to the bitline is overerased and is drawing leakage current. In this case, an overerase correction pulse is applied to the bitline. This is accomplished by applying approximately 5 V to the bitline for a predetermined length of time such as 100 .mu.s.
After application of the overerase correction pulse the bitline is verified again. If bitline current is still high indicating that an overerased cell still remains connected to the bitline, another overerase correction pulse is applied. This procedure is repeated for all of the bitlines in sequence.
The procedure is repeated as many times as necessary until the bitline current is reduced to the predetermined value which is lower than the read current. Then, the procedure is performed for the rest of the cells in the first row and following rows until all of the cells in the memory have been erase verified.
By performing the overerase correction procedure after each erase pulse, the extent to which cells are overerased is reduced, improving the endurance of cells. Further, because overerased cells are corrected after each erase pulse, bitline leakage current is reduced during erase verify, thus preventing undererased cells from existing upon completion of the erase verify procedure.
Although the APDE method is effective in eliminating overerased cells, it is limited in that since the sources and wordlines (control gates) of the cells are grounded during overerase correction, overerased cells will draw background leakage current while the overerase correction pulses are being applied. The leakage current requires the provision of a large power supply.
Even if the process parameters are controlled such that overerase correction pulses will not create undererased cells, the amount by which the threshold voltage distribution can be reduced is inherently limited because there is no mechanism for preventing the threshold voltages of properly erased cells from being further increased by overerase correction pulses applied thereto. In addition, background leakage current is also present during programming and creates similar problems.
These problems are exacerbated as the supply voltage V.sub.cc is reduced in step with the reduction of feature sizes of EEPROMs. The threshold voltages of the erased cells must be reduced to accommodate the lower values of V.sub.cc. This results in more cells in the low threshold voltage portion of the curve in FIG. 2 drawing leakage current.
In a sufficiently low V.sub.cc application, so many cells will draw leakage current that the total bitline leakage current during erase verify can exceed the value corresponding to an erased cell, even if the cell being verified is undererased. This makes it impossible to determine the state of a cell during erase verify and read, and renders the memory inoperative. This problem has remained unsolved in the prior art and has severely hindered the development of reduced voltage EEPROMs.
Another undesirable effect which becomes especially problematic at low values of V.sub.cc is that if V.sub.cc is applied directly to a wordline, it will be insufficient to enhance the channel of a selected cell such that a verify operation can be performed during erase. For this reason, a booster is provided to boost the wordline voltage to a value which is sufficiently higher than V.sub.cc that cell verification can be reliably performed. For a value of V.sub.cc =3 V, the wordline voltage is typically boosted to a value of approximately 4-5 V.
Voltages are applied to bitlines through pass transistors which enable individual bitline selection. The background leakage current loads down the charge pump and increases the voltage drop across the pass transistors, resulting in a lower drain voltage being applied to the cells. If the drain voltage becomes too low, which can result from excessive leakage current, the cell operation can become unstable and unreliable.

Method for erasing flash electrically erasable programmable read-only memory (EEPROM)


A micromirror of a micromirror array of a spatial light modulator used in display systems comprises a mirror plate attached to a hinge that is supported by two posts formed on a substrate. Also the mirror plate is operable to rotate along a rotation axis that is parallel to but offset from a diagonal of the mirror plate when viewed from the top. An imaginary line connecting the two posts is not parallel to either diagonal of the mirror plate.

Spatial light modulators (SLMs) are transducers that modulate an incident beam of light in a spatial pattern in response to an optical or electrical input. The incident light beam may be modulated in phase, intensity, polarization, or direction. This modulation may be accomplished through the use of a variety of materials exhibiting magneto-optic, electro-optic, elastic or other properties. SLMs have many applications, including optical information processing, display systems, and electrostatic printing.
Therefore, what is needed is a spatial light modulator that has a high resolution, a high fill factor and a high contrast ratio. What is further needed is a spatial light modulator that does not require polarized light, hence is optically efficient and mechanically robust.

Micromirror and post arrangements on substrates


A blinding function is generated. The blinding function is applied to a random value to generate a blinded random value. The blinded random value is utilized for one or more scalar multiplications in an elliptic curve cryptographic operation.

A side channel attack on a cryptographic algorithm measures some physical medium associated with a computing system that performs the cryptographic algorithm (e.g., cryptosystem) while the cryptographic algorithm is executing. The measurement can either directly or indirectly be used to determine some private/secret information. Efficient implementations of cryptographic algorithms often require different amounts of work to be performed based on the value of a secret. Typically, there is a difference in the amount of work based on whether a bit in the secret is a logic one or a logic zero. If enough applications of the algorithm with the same key but different public data are measured, then a statistical analysis can be performed to determine which bits were logic ones and which were logic zeros. Examples of such side channel attacks are timing attacks, power analysis and cache-line attacks. In these attacks, monitoring of timing, power consumption and/or cache access associated with the cryptosystem can provide a source of information that can be exploited to break the cryptosystem (i.e., learn operations and/or keys of the cryptographic algorithm in order to illicitly obtain plaintext protected by encryption and/or impersonate a source using a digital signature).

Blinding function in elliptic curve cryptography


The present invention relates to a super absorbent polymer exhibiting more improved liquid permeability while maintaining excellent absorption performance, and a method for producing the same. The super absorbent polymer comprises: a base polymer powder comprising a first cross-linked polymer of a water-soluble ethylenically unsaturated monomer having at least partially neutralized acidic groups; and a surface crosslinked layer formed on the base polymer powder and including a second cross-linked polymer in which the first crosslinked polymer is further cross-linked through an alkylene carbonate having two to five carbon atoms. The super absorbent polymer satisfies predetermined physical properties.

Super absorbent polymer (SAP) is a synthetic polymer material capable of absorbing moisture from about 500 to about 1,000 times its own weight, and each manufacturer has denominated it as different names such as SAM (Super Absorbency Material), AGM (Absorbent Gel Material) or the like. Such super absorbent polymers started to be practically applied in sanitary products, and now they are widely used for preparation of various products, for example, hygiene products such as paper diapers for children or sanitary napkins, water retaining soil products for gardening, water stop materials for the civil engineering and construction, sheets for raising seedling, fresh-keeping agents for food distribution fields, materials for poultice or the like.
In most cases, these super absorbent polymers have been widely used in the field of hygienic materials such as diapers or sanitary napkins. For these applications, the super absorbent polymer should exhibit a high moisture absorbency, it should not release the absorbed water even in the external pressure, and additionally it should well retain the shape even in a state where the volume is expanded (swelled) by absorbing water, and thereby exhibit excellent liquid permeability.
In particular, in recent years, studies have been conducted to provide diapers having a thinner thickness. Accordingly, interests have been growing in so-called pulpless diapers in which the content of pulp is greatly reduced compared with existing diapers, or further, the super absorbent polymer is immobilized via another means such as tacky/adhesive agents without using pulp. As for the pulpless diapers in which pulp content is greatly reduced or pulp is not used as described above, it is known that application of a super absorbent polymer exhibiting more improved liquid permeability and gel strength than previously known is necessary.
This is because, basically, in order for the pulpless diaper, in which the content of pulp is reduced or the use of pulp is excluded, to have an excellent wearing feeling from the user's point of view, the super absorbent polymer contained therein needs to exhibit higher liquid permeability.
Further, in this type of diaper, the content of pulp for buffering/protecting super absorbent polymer particles from the external impact is reduced or the pulp itself is excluded. Thus, in order for the super absorbent polymer to maintain excellent physical properties and shape despite an external impact, it is necessary for the polymer itself to have higher gel strength.
Furthermore, in order for the super absorbent polymer to exhibit and maintain the above-mentioned high liquid permeability, even after the super absorbent polymer particles are swollen by absorbing moisture, the super absorbent polymer needs to be retained in its shape, thereby maintaining voids between particles. This is because voids between the particles act as a flow path to ensure excellent liquid permeability of the super absorbent polymer. For this reason, in order to provide a super absorbent polymer exhibiting more improved liquid permeability and other excellent physical properties as described above, such a super absorbent polymer needs to exhibit a higher gel strength.
Due to the tendency of the diaper development as described above and the characteristics of the super absorbent polymer required therefor, interests have recently been more concentrated on improving the gel strength and the liquid permeability of the super absorbent polymer. However, when it is tried to increase the gel strength of the super absorbent polymer, it is generally known that the basic absorption capacity of the super absorbent polymer is lowered. Thus, there are technical difficulties in improving gel strength and liquid permeability while maintaining the absorption capacity to the maximum, and research for solving these defects has been continued.
Due to the above-described technical requirements, various attempts have been made to improve the liquid permeability and the gel strength of the super absorbent polymer. As a typical example thereof, there may be mentioned a method of adding, to a surface cross-linked super absorbent polymer, a water-soluble polyvalent metal compound, an insoluble inorganic fine particle or a cationic polymer compound as an additive for improving liquid permeability.
However, even with these conventional methods, the liquid permeability and gel strength of the super absorbent polymer are not sufficient, and further, it is true that, as the additive become detached from the surface of the super absorbent polymer particles with time, the liquid permeability tends to be greatly lowered. In addition, when the above-mentioned conventional method is applied, there was a problem that the basic absorption capacity such as the absorbency under pressure is lowered despite the improvement in liquid permeability.
Therefore, there is a continuing need to develop a technique capable of providing a super absorbent polymer having more improved liquid permeability and gel strength while maintaining excellent absorption performance.

Super absorbent polymer and method for preparing same


An electronically controlled warmer drawer that supports a plurality of products, e.g., towels, in a drawer that is attached to a housing is disclosed. The housing includes a plurality of flow paths constructed to facilitate the passage of a heated gas flow through the cavity defined by the drawer. The drawer further includes a plurality of brackets constructed to support the articles to be heated along with a user interface, vents, blower fan, electrical heating element and two internal chambers. The system is controlled by way of the user interface on the front of the housing that interacts with an electronic control system to operate the heating element and fan. A sensor sends signals to the electronic control system to regulate the heating element and fan.

The below-referenced U.S. patents disclose embodiments that were at least, in part, satisfactory for the purposes for which they were intended. The disclosures of all the below-referenced prior United States patents in their entireties are hereby expressly incorporated by reference into the present application for purposes including, but not limited to, indicating the background of the present invention and illustrating the state of the art.
Examples of warming drawers previously patented by Western Industries, Inc. include U.S. Pat. Nos. 7,279,659 and 7,235,762, the entireties of all of which are incorporated herein by reference.
U.S. Pat. No. 6,982,399 relates to a towel warmer having an upper chamber and a lower chamber separated by a partition with a blower located in an upper portion of the housing. A sealable access means encloses the towel warming chamber while a temperature sensor provides an indication of the temperature within the warmer. The towel warmer has a substantially airtight trapezoidal enclosure and a first means consisting of a rhomboidal cavity inclined from front to back to hold the towel to be heated.
U.S. Pat. No. 6,840,589 discloses a towel warmer and dryer cabinet. The towel warmer and dryer cabinet has a front panel supported pivotably on an upper end of a towel rod support member and movable between a retracted position and an extended position. The towel warmer and dryer cabinet further has a securing means constructed to engage a support member for moving at least one towel rod accurately through the front side of the cabinet between retracted and extended positions.
U.S. Pat. No. 6,774,343 pertains to a towel and garment warmer. In the disclosed warmer, a garment or towel is supported by a plurality of rods extending through a portion of the enclosure of the warmer. A cover is pivotably connected to the housing to allow insertion and removal of the garment therefrom. The device for warming towels and other fabric items has a cabinet with an openable top lid.
U.S. Pat. No. 6,525,298 relates to a towel warmer. The towel warmer includes a housing having a pivotable door attached thereto and a cavity with a circulation plate positioned therein. The warmer further includes a hot air towel warmer having a first means disposed within a substantially airtight enclosure having air passages therethrough to support a towel.
U.S. Pat. No. 6,046,436 discloses a hot air towel warmer having a pivotable door constructed to allow passage of a towel into the warmer device. U.S. Pat. No. 6,005,227 discloses a towel warming console cabinet. An enclosure of the disclosed cabinet includes a plurality of supports constructed to receive materials thereon, a fan configured to circulate a heated air flow and a heat unit constructed to warm the circulated flow.
U.S. Pat. No. 5,842,287 relates to a towel warmer having a tubular rack constructed to support a garment to be warmed. U.S. Pat. No. 5,606,640 also discloses an apparatus for warming a towel. U.S. Pat. No. 5,569,403 discloses a towel warmer wherein the towel is removably mounted on a rack within a closed cabinet. Finally, U.S. Pat. No. 5,548,100 discloses an article warmer with heated frame and flexible enclosure.
As the above attempts are lacking in some respect, there exists a need for a state-of-the-art electronically controlled warmer drawer that overcomes these deficiencies.


A FEA model representing a product/part with certain finite elements for metal portion, metal necking failure criteria (critical and fracture strain values defined in form of loading path diagram) and the neck's characteristics (neck's width and a profile of strain values within the width) are received in a computer system. At each solution cycle of a time-marching simulation of a deep draw metal forming process using the FEA model, following operations are performed at each integration point of every finite element: identifying major and minor strain values and corresponding directions from the computed strain values, calculating an equivalent metal necking failure strain value (εe) in the major strain direction with a formula based on corresponding critical and fracture strain values, the neck's characteristics and a characteristic dimension in the major strain direction, and determining metal necking failure, which occurs when the major strain value is greater than εe.

Computer aided engineering (CAE) has been used for supporting engineers in many tasks. For example, in a structure or engineering product design procedure, CAE analysis, particularly finite element analysis (FEA), has often been employed to predict structural behavior (e.g., stresses, displacements, etc.) under various simulated loading conditions (e.g., static or dynamic).
An example of using FEA is sheet metal forming, which has been used in the industry for years for creating metal parts from a blank sheet metal, for example, automobile manufacturers and their suppliers produce many parts using sheet metal forming.
One of the most used sheet metal forming processes is deep drawing, which involves a hydraulic or mechanical press pushing a specially-shaped punch into a matching die with a piece of blank sheet metal in between. Exemplary products made from this process include, but are not limited to, car hood, fender, door, automotive fuel tank, kitchen sink, aluminum can, etc. In some areas of the die, the depth of a part or product being made is generally more than half its diameter. As a result, the blank is stretched and therefore thinned in various locations due to the geometry of the part or product. The part or product is only good when there is no structural defect such as material failure (e.g., cracking, tearing, wrinkling, necking, etc.).
In order to numerically simulate metal necking failure in finite element analysis (e.g., a time-marching simulation of a deep drawing metal forming process), a failure criteria is specified by users of FEA. Prior art approaches have been developed from physical metal specimen testing using average strain around the neck in metal necking failure, for example, data obtained basing on average strain measured with strain gauges. As a result, users need to specify a set of metal necking failure criteria that are finite element mesh (element dimension) dependent. These prior art approaches often cause confusions and difficulties for preparing input data and lead to incorrect simulation because users need to prepare the failure criteria based on these artificial and ad hoc requirement.

Methods and systems for conducting a time-marching numerical simulation of a deep drawing metal forming process for manufacturing a product or part


An apparatus and associated method is provided for precisely positioning a datum surface of a component. The apparatus has a housing defining a tooling datum surface. A collet is supported by the housing that is selectively operable between a retracted mode and an expanded mode. In the retracted mode a clearing disengagement is defined with the component. In the expanded mode a contacting engagement with the component is defined. The contacting engagement and a simultaneous longitudinal force transferred by the contacting engagement to the component pressingly engage the datum surfaces together. The apparatus further has a bias member exerting the longitudinal force and urging the collet to the retracted mode.

Approaches used in performing precise operations on components and component assemblies have necessarily adapted to rapidly changing events affecting factory processes. For example, as miniaturization has proliferated in the electronics market the sheer size of the components and assemblies has rendered some past measurement approaches obsolete. Also, although electronics packages are continually shrinking, the converse is generally true for the feature sets being offered. That is, a predominant demand driving the electronics market now and for the foreseeable future is for more complex and capable devices in ever-smaller sizes.
To keep pace with this evolving market, manufacturers have replaced static measuring tools and fixtures with highly complex processor controlled measurement systems. Successful efforts have also been employed to reengineer the factory to build quality into the process rather than inspect quality into the product.
These and other recent improvements in the art have significantly improved not only the ability to perform precise measurements, but have also forged gains in the often competing goals of enhanced quality and faster throughput. It is to the furthering of those efforts that the embodiments of the present invention are directed.

Fixturing a head spindle assembly with an expanding collet


A method is disclosed for encapsulating plasmids, oligonucleotides or negatively-charged drugs into liposomes having a different lipid composition between their inner and outer membrane bilayers and able to reach primary tumors and their metastases after intravenous injection to animals and humans. The formulation method includes complex formation between DNA with cationic lipid molecules and fusogenic/NLS peptide conjugates composed of a hydrophobic chain of about 10-20 amino acids and also containing four or more histidine residues or NLS at their one end. The encapsulated molecules display therapeutic efficacy in eradicating a variety of solid human tumors including but not limited to breast carcinoma and prostate carcinoma. Combination of the plasmids, oligonucleotides or negatively-charged drugs with other anti-neoplastic drugs (the positively-charged cis-platin, doxorubicin) encapsulated into liposomes are of therapeutic value. Also of therapeutic value in cancer eradication are combinations of encapsulated the plasmids, oligonucleotides or negatively-charged drugs with HSV-tk plus encapsulated ganciclovir.

Throughout this application various publications, patents and published patent specifications are referenced by author and date or by an identifying patent number. Full bibliographical citations for the publications are provided immediately preceding the claims. The disclosures of these publications, patents and published patent specifications are hereby incorporated by reference into the present disclosure to more fully describe the state of the art to which this invention pertains.
Gene therapy is a newly emerging field of biomedical research that holds great promise for the treatment of both acute and chronic diseases and has the potential to bring a revolutionary era to molecular medicine. However, despite numerous preclinical and clinical studies, routine use of gene therapy for the treatment of human disease has not yet been perfected. It remains an important unmet need of gene therapy to create gene delivery systems that effectively target specific cells of interest in a subject while controlling harmful side effects. Gene therapy is aimed at introducing therapeutically important genes into somatic cells of patients. Diseases already shown to be amenable to therapy with gene transfer in clinical trials include, cancer (melanoma, breast, lymphoma, head and neck, ovarian, colon, prostate, brain, chronic myelogenous leukemia, non-small cell lung, lung adenocarcinoma, colorectal, neuroblastoma, glioma, glioblastoma, astrocytoma, and others), AIDS, cystic fibrosis, adenosine deaminase deficiency, cardiovascular diseases (restenosis, familial hypercholesterolemia, peripheral artery disease), Gaucher disease, α1-antitrypsin deficiency, rheumatoid arthritis and others. Human diseases expected to be the object of clinical trials include hemophilia A and B, Parkinson's disease, ocular diseases, xeroderma pigmentosum, high blood pressure, obesity. ADA deficiency was the disease successfully treated by the first human "gene transfer" experiment conducted by Kenneth Culver in 1990. See, Culver, K. W. (1996) in: Gene Therapy: A Primer for Physicians, Second Ed., Mary Ann Liebert, Inc. Publ, New York, pp. 1-198.
The primary goals of gene therapy are to repair or replace mutated genes, regulate gene expression and signal transduction, manipulate the immune system, or target malignant and other cells for destruction. See, Anderson, W. F. (1992) Science 256:808-813; Lasic, D. (1997) in: Liposomes in Gene Delivery, CRC Press, pp. 1-295; Boulikas, T. (1998) Gene Ther. Mol. Biol. 1:1-172; Martin, F. and Boulikas, T. (1998) Gene Ther. Mol. Biol. 1:173-214; Ross, G. et al. (1996) Hum. Gene Ther. 7:1781-1790.
Human cancer presents a particular disease condition for which effective gene therapy methods would provide a particularly useful clinical benefit. Gene therapy concepts for treatment of such diseases include stimulation of immune responses as well as manipulation of a variety of alternative cellular functions that affect the malignant phenotype. Although many human tumors are non or weakly immunogenic, the immune system can be reinforced and instructed to eliminate cancer cells after transduction of a patient's cells ex vivo with the cytokine genes GM-CSF, IL-12, IL-2, IL-4, IL-7, IFN-γ, and TNF-α, followed by cell vaccination of the patient (e.g. intradermally) to potentiate T-lymphocyte-mediated antitumor effects (cancer immunotherapy). DNA vaccination with genes encoding tumor antigens and immunotherapy with synthetic tumor peptide vaccines are further developments that are currently being tested. The genes used for cancer gene therapy in human clinical trials include a number of tumor suppressor genes (p53, RB, BRCA1, E1A), antisense oncogenes (antisense c-fos, c-myc, K-ras), and suicide genes (HSV-tk, in combination with ganciclovir, cytosine deaminase in combination with 5-fluorocytosine). Other important genes that have been proposed for cancer gene therapy include bcl-2, MDR-1, p21, p16, bax, bcl-xs, E2F, IGF-I, VEGF, angiostatin, CFTR, LDL-R, TGF-β, and leptin. One major hurdle preventing successful implementation of these gene therapies is the difficulty of efficiently delivering an effective dose of polynucleotides to the site of the tumor. Thus, gene delivery systems with enhanced transfection capabilities would be highly advantageous.
A number of different vector technologies and gene delivery methods have been proposed and tested for delivering genes in vivo, including viral vectors and various nucleic acid encapsulation techniques. Alternative viral delivery vehicles for genes include murine retroviruses, recombinant adenoviral vectors, adeno-associated virus, HSV, EBV, HIV vectors, and baculovirus. Nonviral gene delivery methods use cationic or neutral liposomes, direct injection of plasmid DNA, and polymers. Various strategies to enhance efficiency of gene transfer have been tested such as fusogenic peptides in combination with liposomes or polymers to enhance the release of plasmid DNA from endosomes.
Each of the various gene delivery techniques has been found to possess different strengths and weaknesses. Recombinant retroviruses stably integrate into the chromosome but require host DNA synthesis to insert. Adenoviruses can infect non-dividing cells but cause immune reactions leading to the elimination of therapeutically transduced cells. Adeno-associated virus (AAV) is not pathogenic and does not elicit immune responses but new production strategies are required to obtain high AAV titers for preclinical and clinical studies. Wild-type AAVs integrate into chromosome 19, whereas recombinant AAVs are deprived of site-specific integration and may also persist episomally.
Herpes Simplex Virus (HSV) vectors can infect non-replicating cells, such as neuronal cells, and has a high payload capacity for foreign DNA but inflict cytotoxic effects. It seems that each delivery system will be developed independently of the others and that each will demonstrate strengths and weaknesses for certain applications. At present, retroviruses are most commonly used in human clinical trials, followed by adenoviruses, cationic liposomes and AAV.
As the challenges of perfecting gene therapy techniques have become apparent, a variety of additional delivery systems have been proposed to circumvent the difficulties observed with standard technologies. For example, cell-based gene delivery using polymer-encapsulated syngeneic or allogeneic cells implanted into a tissue of a patient can be used to secrete therapeutic proteins. This method is being tested in trials for amyotrophic lateral sclerosis using the ciliary neurotrophic factor gene, and may be extended to Factor VIII and IX for hemophilia, interleukin genes, dopamine-secreting cells to treat Parkinson's disease, nerve growth factor for Alzheimer's disease and other diseases. Other techniques under development include, vectors with the Cre-LoxP recombinase system to rid transfected cells of undesirable viral DNA sequences, use of tissue-specific promoters to express a gene in a particular cell type, or use of ligands recognizing cell surface molecules to direct gene vehicles to a particular cell type.
Additional methods that have been proposed for improving the efficacy of gene therapy technologies include designing p53 "gene bombs" that explode into tumor cells, exploiting the HIV-1 virus to engineer vectors for gene transfer, combining viruses with polymers or cationic lipids to improve gene transfer, the attachment of nuclear localization signal peptides to oligonucleotides to direct genes to nuclei, and the development of molecular switch systems allowing genes to be turned on or off at will. Nevertheless, because of the wide range of disease conditions for which gene therapies are required, and the complexities of developing treatments for such diseases, there remains a need for improved techniques for performing gene therapy. The present invention provides methods and compositions for addressing these issues.

Encapsulation of plasmid DNA (lipogenes™) and therapeutic agents with nuclear localization signal/fusogenic peptide conjugates into targeted liposome complexes


A building structure is provided having a combination of a support post with a beam having a generally triangular cross-sectional shape with outwardly directed longitudinally extending flanges at the base and a channel formed along the peak of the beam, roofing sheets on the beam which is supported by a support post which is a rolled rectangular cross sectioned sheet metal component each side of which has a centrally located longitudinally extending stiffening channel formed therein. There is also provided a wall plate between the post and the beam, the wall plate comprising a component rolled to generally channel cross-section one flange of which has an outwardly extending step terminating in a section extended parallel to the channel flanges, and for the flanges to be inclined to the web of the channel. The webs of the channel section of the wall plate has punched tongues projecting outwardly therefrom and which engage the flanges on the beam and the free end of the extended section terminates in a rolled glazing channel.

The detailed disclosure of the beam described and claimed in the specification of my U.S. Pat. No. 5,390,453 is hereby incorporated by reference and detailed descriptions will not be repeated here. The beam is of generally triangular cross-sectional shape and has outwardly directed longitudinally extending flanges at the base while a channel is formed along the peak of the beam. Roofing sheets with downwardly bent hook-shaped ends engage in the channel which is shaped so that the hooked shaped ends cannot be easily retracted. Ceiling panels can be supported on the flanges and the beams are, in use, secured to wall plates, beams or supporting posts.
The beams are used to act as rafter frameworks and are particularly but not exclusively suited for low-cost housing using unskilled labor in the building of such housing. Nevertheless, the nature of the materials used for the components are such that care and some skill is required in the erection of building structures therefrom and it is the object of the present invention to provide means whereby not only is erection made easier but also efficiency and aesthetic appearance of the building improved.


A technique for detecting fraudulent activity in a compromised device involves downloading a software application from a processor that controls access to a resource to an electronic device requesting access to the resource. The software application includes instructions that gather selected information from the electronic device such as mouse coordinates and active windows at a selected time and transmitting the information to the processor for analysis. The analysis includes determining whether more than a single input operation is occurring simultaneously. Simultaneous input operations are an improbable combination of processes for a single electronic device, and suggest a potential fraudulent activity. The technique may include sending a message to a security location for further analysis of the potential fraudulent activity, or the user may be contacted while the transaction attempt is delayed, or the attempted transaction operation may be terminated until enhanced security procedures are implemented.

Many transactions are performed online over a network between a client and a server. For example, a bank may provide a website on a server so that account holders can access their accounts using a browser application on a client electronic device.
However, some online transactions may be fraudulent, i.e., not initiated by the proper account holder. Frequently, such fraud is perpetuated by the introduction of malware into the client over a communication network, e.g., by an email attachment. Such malware is typically designed to allow a fraudster to control the client using a remote access tool such as Remote Desktop. The malware allows the fraudster to perform functions on the client's electronic device in a manner transparent to the client so that detection by either the client or the website server is difficult.
Conventional approaches to detecting fraud in online transactions involve installing anti-malware software, e.g., anti-virus software, on a client. The anti-malware software typically performs a search on the client's electronic device to detect known malware, e.g., viruses, worms, Trojan horses, etc. Such a search is based upon the most up-to-date knowledge of malware infections.

Detecting fraudulent activity from compromised devices


A method of highly efficiently transferring various selected molecules into various cells and a method of fusing cells. Cells and/or selected molecules such as polynucleotide are treated with cold gas plasma to thereby transfer the selected molecules located around cells into the cells, or cells are fused by treating the cells with cold gas plasma. Moreover, an apparatus for transferring selected molecules or fusing cells having a cold gas plasma generation unit for transferring selected molecules into cells is provided.

In genetic engineering and development of medicines in the field of recent medical science, pharmaceutics and others, there is increasing the necessity of transferring a selected molecule, for example, polynucleotides such as genes, proteins, physiologically-active molecules, candidates for medicines and others into cells, followed by inspecting the function of the gene in the cells or the physiological activity of the physiologically-active molecule in them. At present, an electroporation method, a gene gun method, a liposome method, a cell fusion method, a virus vector method and others are employed for transferring selected molecules, but, in any of these, selected molecules could not always be satisfactorily transferred into cells.
The electroporation method and the gene gun method may apply to many cells, but they require complicated operations and are difficult to modify for HTS (high throughput screening). The liposome method is problematic in that the cells to which it may apply are limited. In addition, these methods are all expensive, and even if they could be modified for HTS, they shall be extremely expensive. Further, most of them are not satisfactory in point of the transfer efficiency.
The human and mouse gene arrangements have now been clarified, and it is urgently necessary to analyze the genes having unknown functions so as to clarify their functions. In that situation, it is indispensable to develop a gene transfer method enough for HTS. Even in HTS, it is still desired that the method is efficient and enables functional analysis of various genes. For this, it is also urgently necessary to develop a high-efficiency gene transfer method not for specific limited cells but for various cells.
An object of the present invention is to solve the problems with the related art as above and to provide a high-efficiency method of transferring selected molecules into various types of cells and a method of fusing cells.

Method of transferring a selected molecule into a cell


The present invention describes a method and composition for removing exogenous mucin and protein-mucin deposits from hydrophilic contact lenses.

With the advent of hydrophilic or soft contact lenses, following the successful experiments of Wichterle and Seiderman reported in U.S. Pat. Nos. 2,979,576 and 3,721,657, respectively, the practitioner was given another means to correct visual impairments in his patient population. The main virtues of these lenses were their ease of manufacture, their complete transparency and their increased comfort to the user when compared with hard plastic lenses developed much earlier.
The earliest soft lenses offered commercially in the 1970's were made from polar monomers, e.g., hydroxyethylmethacrylate (HEMA), polymethylmethacrylate (PMMA), or polyvinylpyrrolidone (PVP) polymeric materials having the appearance of soft, transparent hydrogels. Within the past several years, however, other materials such as various silicone based polymers have become available and used for the manufacture of soft lenses.
The increased comfort experienced by the user which has resulted in near universal acceptance of soft contact lenses is brought about by the ability of the lens to absorb water. These lenses, when viewed under high power microscopy, appear as a highly porous matrix. When the lens is swelled in aqueous solutions prior to its initial use by the patient, this polar matrix allows the lens to absorb large quantities of water, in excess of 100 per cent of the weight of the dry lens. Consequently when placed on the eye, the user does not experience the discomfort of the foreign object in the eye but rather experiences the somewhat cooling sensation of the additional fluid being added to the eye.
The water-compatible properties which provide user comfort also are the basis for binding of exogenous materials, leading to formation of deposits on the anterior (air-exposed) surface of the lens. Deposit buildup may be exacerbated by conventional aseptization methods, with hazing of vision, loss of optical acuity, and moderate to severe eye irritation. Deposit formation is a primary cause of dissatisfaction by roughly 1/3 of the lens wearing population to adapt successfully to soft contact lenses. These statistics also make it clear that currently available cleaning methods are inadequate for dealing with problems experienced by patients classified as "heavy" depositors.
In the early 1970's it was first demonstrated that deposits on hydrophilic lenses contained proteins found in the normal human tear fluid. These data were summarized in a 1982 review article by F. C. Wedler & T. Riedhammer, "Soft Contact Lenses: Formation of Deposits," [in CRC Critical Reviews on Biocompatibility, Vol. II, chapter 3, pp. 31-46, CRC Press, Boca Raton, Fla. ] the disclosure of which is hereby incorporated by reference. These findings also refuted the belief that these deposits were bacterial plaques which would, if the "contaminated" lens were not replaced, cause infection and damage to the eye.
Until fairly recently, methods for separation, purification, detection, and quantification of sub-microgram levels of bio-materials obtained from soft contact lenses did not exist. In 1987, biochemical techniques were developed for quantitative analysis of biomaterials deposited on single patients lenses [F. C. Wedler, D. Horensky, B. L. Illman & M. Mowrey-Mckee, "Analysis of protein and mucin components deposited on a hydrophilic contact lenses", Clin. Exptl. Optom., 70: 59-68]. Substantial amounts of tear fluid proteins were detected on "normal" patient lenses with which hazing and eye irritation were not observed. The four major tear fluid proteins detected in these studies were albumin, lysozyme, lactoferrin, and pre-albumin. The most important discovery arising from this works was that "heavy lens deposits did not correlate with deposition of tear fluid proteins, but did coordinate strongly with mucin, a heterogeneous mixture of derivatized polysaccharides.
Prior to this finding, it was believed that proteinaceous materials were the main cause of irritating lens deposits, and based on this, protein-degrading enzymes (proteases) were used in cleaning solutions to remove these irritating deposits. Indeed, U.S. Pat. No. 3,910,296 discloses and claims the use of protease-containing solutions for soft contact lens cleaning. Included in this formulation were sulfhydryl-group containing compounds, needed to activate the protease (papain) and which could also reduce disulfide bonds in the protein substrate, but which have an offensive "rotten egg" odor.
A number of subsequent disclosures have sought to improve on the basic concept of protease-based cleaners. These additional disclosures suggest that other substituents be added to the cleaning solution, that the condition under which cleaning occurs be adjusted, or both. For example, U.S. Pat. No. 4,096,870 suggests the use of the digestive aid pancreatin, a crude mixture of hydrolytic enzymes extracted from hog pancreas, formulated in combination with boric acid and sodium chloride as a cleaning mixture. U.S. Pat. No. 4,285,738 suggest the use of a hypertonic solution of urea and/or a guanidine salt added to the protease formulation along with a sulfhydryl compound or other suitable reducing reagent capable of cleaning disulfide bonds.
Commercially available products for enzymatic cleaning of soft(hydrophilic) contact lenses include, for example, OPTI-ZYME.TM. (Alcon Laboratories) based on porcine pancreatin as the active ingredient, and ALLERGAN ENZYMATIC.TM., EXTENZYME.TM., and PROFREE/GP.TM. (Allergan Pharmaceuticals) based on papain.
Now that the major cause of extraneous heavy lens deposits is known to be mucin, not proteins, it becomes clear why the majority of currently available commercial enzyme-based cleaners fail to remove heavy deposits. Although the enzymes contained in these cleaners will specifically attack and degrade proteinaceous materials, they are ineffective against mucin, which is a heterogeneous mixture of complex carbohydrates (mucopolysaccharides) and carbohydrate surrounding a protein core (glycoproteins).
Since presently available enzyme-based cleaning solutions fail to degrade or remove mucin deposits from soft contact lenses, there is obviously a need to develop a new, second-generation cleaner, based on mucin-degrading enzymes. These mucin degrading enzymes could be used either alone or in combination with proteases to enhance the cleaning of heavily deposited hydrophilic lenses.

Method for removing exogenous deposits from hydrophilic contact lenses


A plasma display apparatus is equipped with a signal input terminal responsive to a user's application. The plasma display apparatus includes a panel including a pair of substrates, wherein at least one of the substrates is transparent. The substrates are placed opposite to each other to form a discharge space in between, and electrodes are provided to the substrate. The plasma display apparatus also includes a display driving circuit block, disposed on a chassis and equipped with at least one signal inputting connector which applies a signal to the panel to perform displaying, and an input signal circuit block detachable to the signal inputting connector of the display driving circuit block.

Plasma display apparatuses are widely used as display apparatuses installed in busy sections of a city for the general public, or installed at a home for a family to enjoy videos on a large screen. A plasma display panel (PDP) has better characteristics than a liquid crystal panel in the following points: responding at a faster speed, a wider viewing angle, easier to produce a larger screen, and higher display quality due to self-light-emitting.
In the PDP, display cells partitioned with barrier ribs are disposed on a board, and a phosphor layer covers the display cells. An ultraviolet ray generated by gas discharge excites the phosphor to emit light for color display.
The PDP is largely classified into an alternating current (AC) driving system and a direct current (DC) driving system, and into a surface discharge and an opposite discharge. A three-electrodes, AC driving and surface discharge PDP takes the mainstream of the PDP because of its high resolution, easiness of producing a large screen and easiness of fabrication. This PDP comprises the following elements:                a first substrate having a pair of display electrodes adjacent to each other in parallel; and        a second substrate having address electrodes arranged in a direction crossing the display electrodes, barrier ribs and a phosphor layer.This structure allows the phosphor layer to be rather thick, and is suitable for color display.
On the other hand, the PDP can be used as a large size display in various applications, so that its input signal terminal is desirably connectable to various external apparatuses such as a personal computer, a television receiver, and a video cassette recorder. Those apparatuses output their video signals including information signals.
A plasma display apparatus is thus equipped with various signal-input-terminals to receive as many external signals as possible. Users in the consumer market, however, scarcely use every signal-input terminal, but use one specific terminal for a particular external apparatus. Therefore, a number of the various signal-input terminals are useless for the users in the consumer market.
Plural types of plasma display apparatuses may be produced so that particular signal-input terminals responsive to users' applications can be provided. However, there will be a lot of models of one product because of the many applications discussed above, which lowers the productivity.
The present invention addresses the foregoing problem and aims to provide with ease a plasma display apparatus having a signal-input terminal responsive to a user's application.

Matsushita Electric Industrial Co., Ltd.


In a system having two or more gateway apparatuses connected to both first and second networks having mutually different address systems, a gateway apparatus is provided with a translation table for associating IP addresses with node IDs. The gateway apparatus inquires other gateway apparatuses whether other gateway apparatuses are administering the same address as an IP address generated for a newly added device. If there is another gateway apparatus that is administering the same address, the IP address is prevented from being registered in the translation table.

The present invention relates to a gateway apparatus and its address administration method whereby different networks of two kinds can be connected and devices on the networks can be assigned unique addresses. In particular, the present invention relates to gateway apparatuses whereby when devices of networks each including a gateway apparatus are connected, addresses can be assigned so as to avoid duplication between two gateway apparatuses.
In recent years, digitization of AV (audio-visual) devices represented by TVs and VTRs have been promoted. Digital satellite broadcast receivers, i.e., set top boxes (hereafter abbreviated to STBs), video cassette recorders (VCRs), video cameras and hard disks using a digital recording system, and recording apparatuses using an optical disk such as a DVD-RAM have made their appearance. Among these AV devices, there are increasing devices that adopt an IEEE 1394 serial bus (hereafter referred to as 1394 bus), whereby fast data communication of high quality can be conducted in connection with another AV device. The 1394 bus has a data transfer rate of a maximum 400 Mbps and an isochronous transfer mode whereby video and audio data can be transmitted in real time. In addition, the 1394 bus has an advantage that the user's operation can be reduced because insertion and removal of a cable are detected and a node ID having 16 bits is automatically assigned to each device. Therefore, attention has been paid to the 1394 bus as a standard interface of digital AV devices. Hereafter, an AV network using the 1394 bus is referred to as 1394 network.
On the other hand, in-home network construction has begun as well as a result of spread of information devices represented by PCs (Personal Computers) and the Internet. As one form of in-home networks, there can be mentioned an information system network that aims at sharing internet access and a printer among a plurality of PCs, such as notebook computers used by individuals and a desktop PC shared by family members. On this network, TCP/IP utilized on the Internet as a protocol is typically used, and an address called IP address is used to identify each device. At the present time, a version called IPv4 using a 32-bit address is the mainstream. In recent years, however, a new version expanded in address to 128 bits and called IPv6 (Internet Protocol version 6) has been drawn up.
As shown in FIG. 2, an IPv6 address 200 includes a network prefix 201 represented by 64 high-order bits thereof and an interface ID 202 represented by 64 low-order bits thereof. The network prefix 201 is used as an identifier of a connected network. A value notified of by a router by utilizing an automatic stateless address autoconfiguration function is set in the network prefix 201. The interface ID 202 is used as an identifier of a device that exists on the network. In the case of a LAN using a twist pair line, the interface ID 202 is set on the basis of a 48-bit MAC address. In the case of a 1394 bus, the interface ID 202 is set on the basis of a node unique ID (hereafter abbreviated to unique ID) having 64 bits. Hereafter, an information system network using the TCP/IP is referred to as IP network.
For exchanging data directly between a device on the IP network and a device on the 1394 network, a gateway apparatus having both interfaces in order to connect the two networks becomes necessary.
In JP-2001-202317, there is described a method of controlling a digital AV device or the like connected to a 1394 bus via such a gateway apparatus, by using a controller on the IP network.
According to the above described conventional technique, one gateway apparatus, which forms the nucleus in the home, has an address translation table that associates IP addresses and unique IDs previously provided to devices on the 1394 network with each other, and transmits data received from the IP network or the Internet to a device on the 1394 network on the basis of the address translation table.
In a system configuration in which two or more gateway apparatuses exist on an IP network and a 1394 network exists for each of the gateway apparatuses, a user connects a device on a 1394 network to a device on a different 1384 network by using a 1394 bus. Such a situation is conceivable. In this case, it turns out that devices that have existed on different 1394 networks exist on one 1394 network. User's operation of updating contents of address translation tables administered by the two gateway apparatuses so as not to cause duplication becomes necessary. Even in the case where the gateway apparatuses automatically update the address translation tables, a mechanism for preventing duplication of contents of address translation tables among a plurality of gateway apparatuses becomes necessary.

Gateway apparatus, address administration method, and audio-video apparatus having gateway function


The present invention provides a laser leveling system for forming a reference line or a reference plane by a laser beam. The laser leveling system comprises a laser light emitting means for emitting a laser beam, a projection optical system for projecting the laser beam irradiated from the light emitting means, a rotating unit for rotating the light beam projected by the projection optical system, and a leveling means for tilting the rotating unit, whereby a horizontal reference plane and a vertical reference plane are formed by the light beam, and a reference irradiation spot is formed on the horizontal reference plane or on the vertical reference plane.

The present invention relates to a laser leveling system, which irradiates a laser beam in vertical or horizontal directions and performs scanning while the laser beam is irradiated to form a reference line or a reference plane.
To install a partition in a building or to mount lighting fixtures such as fluorescent light on a ceiling, positioning is performed according to a marking line, which is marked on a floor, and a laser leveling system is used to project the position indicated by the marking line on a ceiling surface, a wall surface, etc.
The laser leveling system is to form a reference line or a reference plane. Thus, position, posture, etc. of the laser leveling system to be installed must be accurately aligned with a predetermined position or posture.
FIG. 15 shows a conventional type laser leveling system.
Inside a main unit 1, there are provided a laser beam emitting means, a rotary driving unit, a controller, etc. On the main unit 1, a rotating unit 2 is installed, and a laser beam is irradiated from the rotating unit 2, and scanning by the laser beam is performed by rotation of the rotating unit 2. The main unit 1 is mounted on a base plate 5 via at least two leveling screws 3 and 4. By adjusting the leveling screws 3 and 4, it is possible to adjust tilting of a rotation axis of the rotating unit 2 to a predetermined condition. On lateral sides of the main unit 1, bubble tubes 8 and 9 are provided so that these bubble tubes can be seen from outside. To adjust tilting, at least one of the leveling screws 3 and 4 is turned, and tilting of the main unit 1 is adjusted according to whether the leveling screws 3 or 4 are moved in or out. Further, tilting adjustment by the leveling screws 3 and 4 is carried out while watching the bubble tubes 8 and 9.
Because the movement of the leveling screws i.e. height adjustment is converted to tilting adjustment, a tilting direction and amount of tilting cannot be determined intuitively, and some skill is required for the adjustment. Also, tilting is judged by watching position of air bubbles in the bubble tubes, and this results in wide variations due to individual difference of the operator. This also requires some skill in determining with high accuracy.
Further, in case a vertical reference plane is formed by rotary scanning, an auxiliary tool is used, and the laser leveling system is laid horizontally so that the rotation axis of the rotating unit 2 is directed in a horizontal direction. In this case, it is necessary to adjust a direction of the vertical plane. Unless the leveling screws are positioned perpendicularly to the adjusting direction, it is very difficult to adjust the direction by means of the leveling screws. For this reason, it is necessary to provide the auxiliary tool with a adjusting means, etc. In case it is tried to align the laser beam irradiated for rotary scanning with the marking line on the floor, it is difficult to align because the laser beam is linear. Further, in case locus of rotary scanning of the laser beam is at a separate position, and it is difficult to align the laser beam visually while operating at the main unit side. It is necessary to watch the bubble tubes from above, but if the leveling system is placed at a position higher than the line of sight, it is very difficult to perform adjustment.