An apparatus and method for interconnecting digital and analog circuitry on separate substrates within a single integrated chip package attenuates logic level signals on one substrate, transmits the attenuated signals to another substrate, and amplifies the attenuated signals back to logic level signals.

The present invention relates generally to interconnecting analog and digital integrated circuits and, more particularly, to interconnecting such in a manner that reduces noise.
Analog electrical signals are often processed by digital computational circuitry. This requires converting the analog signal into a stream of discrete numerical values, in other words, a digital signal. This conversion typically takes place in an analog to digital (A/D) converter that periodically samples the analog signal and represents those samples with digital values. To convert digital signals back to analog signals requires a digital to analog (D/A) converter.
The digital circuits that process digital signals, however, generate noise that can interfere with the A/D and D/A conversion processes. This interference can lead to decreased accuracy or erroneous conversions. When low accuracy for such conversions will suffice, the converter circuits and the computational circuits can coexist on the same integrated circuit substrate. Where higher accuracy is required, however, the single substrate technique proves to be inadequate because of the noise produced by the digital circuits.
Currently, circuits for applications requiring high accuracy address this noise problem by the configuration in FIG. 1, which incorporates two separate integrated circuit devices, with separate substrates, into a single package. A substrate 10 contains analog circuitry 12, while a separate substrate 11 contains digital circuitry 13. The two substrates 10 and 11 are interconnected via traditional lead bonding wires 15. The lead bonding wires 15 are connected to substrates 10 and 11 through bonding pads 14. In the alternative, bonding wires 15 can be bonded from one substrate to a stationary lead frame element, and then from that element to the other substrate. These interconnections carry binary signals of the logic levels required by the logic circuit.
Unfortunately, this configuration does not eliminate interference from digital signals needed for conversion of signals. For D/A converters, data must be transferred from the digital circuit to the analog circuit, and for A/D converters, data must be transferred from the analog circuit to the digital circuit. Also, clock signals that drive the converters and synchronize the transfer of data between the analog and digital circuits are digital signals. These data and clock signals are carried by interconnect bonding pads on the analog circuit substrate. The bonding pads are capacitively coupled with the underlying substrate enough to allow the digital signals to create noise and interfere with the conversion process.
The bonding pad to substrate coupling problem is further aggravated by two factors. First, the advent of fine line lithography has made the conducting, insulating, and semiconducting features of the devices extremely small (fractions of a micron), while lead bonding technology continues to require comparatively large bonding pads (10,000 square microns in area). As this trend continues, the relative influence of bonding pad signals into the circuit substrate increases. Second, all circuits must have static protection circuits connected from the bonding pads to the substrate to protect against static discharge during packaging. These static protection circuits aggravate the bonding pad-to-substrate coupling problem.
In the particular case of a converter using switched capacitor, delta sigma conversion techniques, noise is also caused by the associated decimation filter. In that case, a very high clock frequency is used to sample both the analog input voltage and a reference voltage at the input of a switched capacitor filter. After each high frequency cycle, a comparator ascertains whether the filter output is positive or negative. The polarity of the reference potential on the next cycle is then determined by the output of the comparator. The converters output a single bit on each high frequency clock cycle and use a digital decimation filter to reduce the sample rate while increasing the resulting low sample frequency accuracy. A typical delta sigma converter capable of converting frequencies up to 20 kilohertz requires a 3.072 megahertz high frequency clock. The decimation filter, in turn, would output 16 bit samples at 48 kilohertz. For this typical case, the noise produced by the decimation filter can, if not properly isolated from the analog circuitry, reduce the accuracy of the sampled signals in the switched capacitor section, causing a loss of conversion accuracy.
In light of the foregoing, there is a need to interconnect signals between analog conversion devices and digital processing devices in a manner that reduces the noise coupled into the substrate of circuits.

Low noise method for interconnecting analog and digital integrated circuits


The present invention provides an optical encoder capable of using the recesses and convexes of a movable plate and a fixed plate to accurately generate a Z phase signal in synchronism with an A/B phase signal. Phase type diffraction gratings on the moving and fixed plates including a plurality of tracks with different grating pitches cause parallel coherent beams to interfere with one another, and a light receiving part detects the intensity of light to obtain a plurality of synchronous signals with different periods. On the other hand, the light receiving part detects light spots formed by condensing elements on the movable plate to generates a single pulse per rotation as a reference position. One of the plurality of synchronous signals that has the shortest period is selected as an A/B phase signal that depends on the movement of the movable plate. The conjunction of the reference position signal and the plurality of synchronous signals is determined as a Z phase signal indicating the origin of the movable plate, thereby obtaining a Z phase signal in synchronism with one pulse of the A/B phase signal.

(First Conventional Example)
Optical encoders are roughly classified into two types based on the difference in their position detection methods: an incremental type and an absolute type (an absolute position detecting type). The configuration and operation of a conventional incremental type encoder are described below. As shown in FIG. 49, a conventional incremental type encoder comprises a light source 501; a collimator lens 502 for making beams from the light source 501 parallel; a movable plate 503 that rotates around a shaft 512; a fixed plate 506 disposed opposite to the movable plate 503; and a light receiving device 509 with two light receiving parts 510 and 511.
The movable plate 503 has an A/B phase signal region in which slits or diffraction grating 504 is equal pitch on its circumference; and a Z phase signal region in which only one slit 505 is disposed on its circumference. Similarly, the fixed plate 506 has an A/B phase signal region in which slits or diffraction grating 507 is disposed at the same pitch as in the movable plate; and a Z phase signal region in which only one slit 508 is disposed on its circumference. The light receiving part 510 of the light receiving device 509 detects light that has been transmitted through the diffraction grating 504 of the movable plate 503 and the diffraction grating 507 of the fixed plate 506. The light receiving part 511 of the light receiving device 509 detects light that has been transmitted through the slit 505 of the movable plate 503 and the slit 508 of the fixed plate 506.
By detecting light that has been transmitted through the A/B phase signal regions of the moving and fixed plates 503 and 506 (the diffraction gratings 504 and 507), a signal depending on the rotating angle of the movable plate 503 (an A/B phase signal) is detected, and by detecting light that has been transmitted through the Z phase signal regions (the slits 505 and 508), a signal representing the origin of the movable plate 503 (a Z phase signal) is detected. Generally, an output signal from the light receiving part 509 is binarized into a pulse signal, which is then processed to detect the position. To process the signal easily, the Z phase signal is desirably synchronized with the A/B signal. Thus, the pulse of the Z phase signal must be synchronized with only one pulse of the A/B phase signal.
Next, a method for creating a light shielding pattern such as slits is described with reference to FIG. 50. As shown in FIG. 50A, a photo resist 522 is applied to the surface of a transparent substrate 521. Then, a mask 523 with a specified pattern which has been produced by electron beam exposure is adhered to the surface of the photo resist 522 or allowed to approach the photo resist 522 as in FIG. 50B. The substrate is then irradiated with light of a wavelength region that can be responded by the resist in order to make only the exposed resist soluble or insoluble, and the mask is then removed. When the substrate 521 is then immersed in a resist solvent, a mask pattern 522' from the resist is transferred to the surface of the substrate 521 as in FIG. 50C. The substrate 521 with the mask pattern 522' transferred thereto is installed in a deposition apparatus (not shown) to deposit a metal 524 such as chrome thereon as in FIG. 50D. The substrate 521 is subsequently removed from the deposition apparatus, and an organic solvent such as acetone is used to remove the photo resist 522' remaining on the substrate 521 as in FIG. 50E. As a result of this series of operations, a light shielding pattern 525 such as slits is formed on the substrate 521.
As described above, a large number of operations are required to produce the light shielding pattern 525 such as slits on the substrate 521. In addition, the mask 523 and the substrate 521 cannot be aligned with each other easily. Thus, as is well known, high costs are required to form a pattern such as slits on the moving and the fixed plates 503 and 506. Consequently, incremental type optical encoder uses phase type optical elements in the A/B phase signal regions (the diffraction gratings 504 and 507) of the moving and the fixed plates 503 and 506 to reduce costs.
Phase type optical elements can be produced by forming recesses and convexes on the surface of the substrate. A phase type optical element manufacturing process is shown in FIG. 51. A transparent resin 532 such as acryl or polycarbonate which is made flowable by heating is poured into a mold 531 of a specified shape and solidified therein. The phase type optical element has the shape of the mold transferred thereto. Compared to the method for producing a light shielding pattern such as slits on the surface of the substrate, this method does not require the substrate and the pattern to be aligned with each other or require operations such as application of a photo resist, ultraviolet radiation, development, deposition of a metallic film, and washing thereof.
As one example in which the A/B phase signal region comprises a phase type diffraction grating, which is one of the phase optical elements, a conventional incremental type encoder shown in, for example, JPA6-042981 is known. The configuration of this encoder is shown in FIG. 52. In this figure, the light source 501 comprises a semiconductor laser or a relatively coherent light emitting diode. Beams from the light source 501 are made parallel by the collimator lens 502 and are incident on the movable plate 503. The movable plate 503 has a phase type diffraction grating 534 that mainly generates .+-.1 order diffracted light, and is disposed approximately perpendicularly to the optical axis of the parallel beams so that it can be rotated around a rotation center 512 parallel to the optical axis. The fixed plate 506 has a phase type diffraction grating 537 with a grating pitch P equal to that of the phase type diffraction grating 534 on the movable plate 503, and is disposed approximately perpendicularly to the optical axis. The light receiving part 510 receives light formed based on the relative locational relationship between the phase type diffraction gratings 534 and 537. Beams from the light source 501 are made parallel by the collimator lens 502 and are then approximately perpendicularly incident on the movable plate 503. The light incident on the movable plate 503 is diffracted into a +1 order diffracted beam and a -1 order diffracted beam by the phase type diffraction grating 534 on the movable plate 503. The light is incident on the phase type diffraction grating 537 of the fixed plate 506 and diffracted into a +1 order diffracted beam and a -1 order diffracted beam, respectively. Since the phase type diffraction gratings 534 and 537 have an equal grating pitch P, the diffraction angles of the phase type diffraction gratings 534 and 537 are equal. Consequently, the optical path of the light diffracted into a -1 order beam by the phase type diffraction grating 534 and then into a +1 order beam by the phase type diffraction grating 537 ((-1, +1) order diffracted light) becomes equal to the optical path of the light diffracted into a +1 order beam by the phase type diffraction grating 534 and then into a -1 order beam by the phase type diffraction grating 537 ((+1, -1) order diffracted light), so these optical paths interfere with each other, varying the intensity of the light. Since the interference condition depends on the movement .delta. of the movable plate 503, the intensity of the light varies depending on the movement .delta. of the movable plate 503. That is, since the movement .delta. of the movable plate 503 varies the amount of light received by the light receiving part 510, the movement of the movable plate 503 can be detected.
On the other hand, methods for providing recesses and convexes on the surface instead of slits have been examined for the Z phase signal region, as in the A/B phase signal region. As shown in FIG. 53, a condensing lens 541 is provided on the movable plate 503 so that a condensed spot can be received by the light receiving part 511 to detect the movement reference point of the movable plate 503. In this case, the accuracy in detecting the Z phase is substantially determined by the sizes of the condensed spot and the light receiving part 511, and increases as the sizes decrease.
(Second Conventional Example)
An incremental type optical encoder shown in FIG. 49 detects the position of the movable plate 503 based on the movement of the A/B phase signal relative to the Z phase signal as a reference. Thus, position detection cannot be carried out while power is being supplied, and it is essential to detect the position of the reference. On the contrary, absolute type optical encoders that can detect a current position at any time from any position depending on the different slit patterns are known.
The configuration and operation of absolute type optical encoders are described. As shown in FIG. 55, a conventional absolute type optical encoder comprises a light source 601; a collimator lens 602 for making beams from the light source 601 parallel; a movable plate 603 rotating around a shaft 612 and having a plurality of slit tracks with slits 604 disposed at approximately equal pitch on its circumference; a fixed plate 606 disposed opposite to the movable plate 603 and having a plurality of slits 607 corresponding to the plurality of slit tracks 604 on the rotating plate 603; and a light receiving device 609 having a plurality of light receiving parts 610 corresponding to the plurality of slits 607. The slits 604 are installed at a different pitch in each slit track on the rotating plate 603. Each light receiving part 610 detects light transmitted through a slit 604 of the movable plate 603 and a slit 607 of the fixed plate 606. Based on the pattern of a detection signal from the light receiving part 610, the absolute position of the rotating plate 603 can be detected.
(Third Conventional Example)
The position of an object has been commonly detected in a non-contact manner by irradiating the object with light, projecting its image onto a television camera, and binarizing an output signal from a linear array sensor to detect the position, or forming a slit in a moving object, transmitting light from the light source through the slit in such a way that the light is incident on a light receiving part, and binarizing the output signal from the light receiving part to detect the moving reference point of the moving object. A conventional position detection method shown in, for example, JPA2-44202 is described with reference to FIG. 56.
FIG. 56 shows a plan view of a position detection apparatus that is a third conventional example. In this figure, 701 is a light source; and 702 is a moving object on which a slit 703 is formed. Reference numeral 705 designates a light beam that has passed through the slit 703, and 704 is a light receiving part. The moving object 702 is disposed between the light source 701 and the light receiving part 704, and moves perpendicularly to the shaft which couples the light source 701 and the light receiving part 704. In response to the movement of the moving object 702, the light beam 705 also moves. AA is the distance between the light source 701 and the moving object 702, and B is the distance between the moving object 702 and the light receiving part 704. In addition, .DELTA. is the movement of the moving object 702, and .delta..delta. is the movement of the light beam 705. In this case, the movement .delta..delta. of the light beam 705 can be expressed as the following Equation (1): ##EQU1##
The incremental type encoder that is the first conventional example is disadvantageous in that if the Z phase signal region has recesses and convexes on the surface instead of slits, the Z phase detection accuracy cannot be improved easily. The diameter of the condensed spot is determined by the size of the light source 501 and the focusing distance of the collimator lens 502 in geometrical optics. As shown in FIG. 54, if the size of the light source 501 is referred to as .phi.s1, the focusing distance of the collimator lens 502 is referred to as fs1, and the focusing distance of the condensing lens 541 installed on the Z phase signal region is referred to as fs2, then the diameter .phi.s2 of the condensed spot 551 can be expressed as the following Expression (2) based on the Gauss's formula in geometrical optics. ##EQU2##
Thus, to reduce the diameter .phi.s2 of the condensed spot 551, firstly the size .phi.s1 of the light source 501 may be reduced, secondly the focusing distance fs1 of the collimator lens 502 may be increased, or thirdly the focusing distance fs2 of the condensing lens 541 on the Z phase signal region may be reduced. To reduce the size of the first light source 501, however, a light shielding part such as a pin hole may be formed near the light source 501, but this disadvantageously reduces the amount of available light. In addition, since the sizes of the A/B and Z phase signal regions determine the diameter of required parallel beams, that is, the diameter of the collimator lens 502, increasing the focusing distance fs1 of the second collimator lens 502 reduces the use efficiency of light from the light source 501. In some methods for generating signals in the A/B phase signal region, the distance between the fixed plate 506 and the light receiving part 511 must be increased to separate unwanted diffracted light from, for example, the fixed plate 506. This prevents the focusing distance fs2 of the condensing lens 541 on the Z phase signal region from being significantly reduced. Alternatively, the light receiving part 510 for the A/B phase signal may be separated from the light receiving part 511 for the Z phase signal so that the light receiving part 510 for the A/B phase signal can be installed at a desired distance from the fixed plate 506, while the light receiving part 511 for the Z phase signal can be installed closer to the fixed plate 506. This embodiment, however, involves a complicated structure and requires accurate assembly, thereby increasing costs.
The light source 501 of the optical encoder normally comprises a light emitting diode, and the light emitting diameter .phi.s1 of the light emitting diode is not smaller than 100 .mu.m. In addition, the focusing distance of the collimator lens 502 must be about 5 mm or larger depending on the size of the product or the specification, and the distance between the movable plate 503 and the light receiving part 511 must be about 20 mm or larger. As a result, the diameter of the light spot of the condensing lens 541 installed on the movable plate 503 can be calculated as about 400 .mu.m, using Equation (2). Compared to the A/B phase signal with a pitch (or a period) of 10 .mu.m, the Z phase signal is wide. To increase the accuracy of Z phase detection, the size of the light receiving part 511 may be reduced compared to the light spot diameter to set a higher threshold used in binarizing a detected signal. This encoder, however, is likely to be subjected to electric noise or the variation of the light intensity of the light source 501, so it cannot detect the Z phase stably.
Furthermore, this method cannot easily synchronize the Z phase signal with the A/B phase signal used to detect the movement of the movable plate 503. In the method shown in FIG. 53, the A/B phase signal has a wave form determined by the relative locational relationship between the movable plate 503 and the fixed plate 506, whereas the Z phase signal can be generated without the use of the fixed plate 506 and has a wave form determined by the relative locational relationship between the movable plate 503 and the light receiving part 511. Thus, to synchronize the A/B phase signal with the Z phase signal, the elements in the movable plate 503, fixed plate 506, and light receiving part 511 must be positioned very accurately. Furthermore, a slight offset among these elements may prevent the A/B phase signal and the Z phase signal from being synchronized.
In addition, in the absolute type encoder that is the second conventional example, a plurality of slit tracks are formed on the moving and the fixed plates 603 and 606, and the slits 604 are disposed at a different pitch in each slit track. This prevents the use of phase type optical elements with recesses and convexes at an equal pitch on the surface of the substrate, as in the incremental type encoder of the first conventional example, and requires the deposition of a thin film of metal on a transparent substrate to form a slit as shown in FIG. 50. Consequently, costs cannot be reduced easily.
In the position detection method that is the third conventional example, to improve the accuracy in detecting the moving reference point of the moving object 702, the movement .delta..delta. of the light beam 705 may be increased using the movement .DELTA. of the moving object 702. Specifically, the distance B may be increased to reduce the distance AA. When, however, the distance B is increased while the distance AA is simultaneously reduced, the diameter of the light beam 705 is increased on the light receiving part 704. This reduces the accuracy in detecting the moving reference point of the moving object 702. On the other hand, if the size of the slit 703 is excessively reduced to reduce the diameter of the light beam 705, the light may be diffracted, thereby increasing the diameter of the light beam 705 on the light receiving part 704. In addition, if the size of the slit 703 is reduced, the amount of light received by the light receiving part 704 may be reduced, thereby enhancing the effects of noise and reducing the accuracy in detecting the moving reference point. Furthermore, to prevent the effects of diffraction, the distance B between the slit 703 and the light receiving part 704 may be reduced. When this distance is reduced, however, the moving object 702 may contact with the light receiving part 704 and both may be damaged.

Optical encorder for detection having a moving reference point

Matsushita Electric Industrial Co., Ltd.


There is provided a method for welding together two metal components to form a large structure suitable for use as an aerospace component. The method comprises the steps of providing two metal components to be welded together, each component having a length, a width, a height and a surface to be welded, the surface to be welded of at least one of the metal components including a feature extending substantially the length of the component, the feature reducing the contact width of the surfaces to be welded of the two components to less than the width of each component; and welding together the components. There is also provided a large structure so created. There is also provided a method for welding together two metal components to form a part or a whole of a spar for a wing for an aircraft and a spar so created.

This invention relates to a method of welding together two metal components to form a large structure which may be suitable for use as an aerospace component and to a large structure so created. In this context, an aerospace component means one that forms part of a fixed-wing aircraft, a helicopter, a missile, a satellite, a space structure or the like. The invention relates particularly, but not exclusively, to a method of welding together two large metal components to form a part or a whole of a spar for a wing of an aircraft and to a spar so created.
In many applications it is necessary to weld together two large metal components. In many applications, it is also useful if the two components have different properties, thereby creating a structure having certain properties in one section and different properties in another section. For example, a spar in the wing of an aircraft is subject to forces in its upper section different from those in its lower section and it is therefore advantageous if the two sections are constructed from metals having different properties.
Large aircraft wings are assembled from many components by joining them together with fasteners (examples of which are bolts and rivets). Each wing typically has two main spars, a forward spar and a rear spar, both running the length of the wing. Some large wings also have a centre spar. Each spar has a length, measured in a direction from the joint of the wing and the fuselage to the wing tip, and a height, measured in a direction from the upper surface to the lower surface of the wing (typically being a maximum of the order of 1 to 2 meters in a large transport aircraft, but decreasing steadily along the length of the wing to the wing tip). The spar is relatively narrow along most of its height but the upper and lower portions are of a greater width (typically no more than 200 mm) so that the overall cross-sectional shape of the spar is usually substantially that of a 'C', although other shapes such as an 'I' are possible. The spar is strengthened at regular intervals along its length by stiffeners which are substantially the same height as the spar but have a width greater than the width of the spar away from its top and bottom portions. The stiffeners take the form of plates located transverse to the spar length.
A spar can be constructed from many individual components which are riveted and bolted together (known as a fabricated spar) or from one piece (from plate material, an extrusion or a forged billet) which is then machined (known as an integrally-machined spar). Fabricated spars can be formed from metal components having different properties, which are bolted together. However, fabricated spars are labour-intensive to assemble, requiring the drilling of many holes and the setting of rivets and bolts. They are also expensive because the assembly process requires sophisticated tooling, and they are heavier because of the material overlap and the rivets and bolts. They are also at greater risk of fatigue damage due to the large number of fastener holes. The advantages of integrally-machined spars are that material overlap is minimised and bolts and rivets are not required (thereby reducing the overall weight) and sophisticated tooling is not needed for assembly. However, such spars must be machined from one piece of material, which material must be chosen as a compromise between the requirements at the top of the spar (mainly compressive loads) and the requirements at the bottom of the spar (mainly tensile loads).
An alternative possibility we have considered is that the spar could be formed from two metal components, the metals having different properties, which have been welded together. In this case, the spar could be machined before or after welding. Welding of aerospace structures has to be carried out to the highest standards, and only certain high-quality processes are acceptable. One method that is particularly suitable for welding together metals having different properties is friction stir welding. Friction stir welding is a well-known and useful welding process but is, unfortunately, limited by the depth of welding that can be achieved. Currently the maximum depth of material which can be reliably welded by friction stir welding is about 6 to 10 mm, which makes it apparently unsuitable for welding components of large structures such as spars.


A method for base-coating a porous ceramic catalyst support includes coating the support with a passivation coating via vacuum infiltration, and subsequently exposing the support to a microwave field to dry the coating and form a polymerized film. The method further includes coating the support with a catalyst coating or washcoat, and subsequently exposing the support to a second microwave field, thereby removing water from the catalyst coating or washcoat.

The present invention relates to processes for applying catalyst or catalyst support coatings onto ceramic supports. More particularly, the invention relates to methods for coating ceramic substrates with catalyst coatings wherein a pre-coating or passivation step is used to improve the properties of the catalyzed substrates, by reducing catalyst and/or support coating diffusion into the fine pore and microcrack structure of the substrates and to drying the passivation and catalyst coatings subsequent to application.
Recent attention has focused on basic improvements in the design and performance of ceramic wall-flow honeycomb filters for treating diesel exhaust gases to address tightening diesel engine emissions regulations being adopted in the United States and Europe. Design changes allowing for the use of catalyst coatings to control hydrocarbon and/or nitrogen oxide emissions are being implemented along with other improvements. The goal is to develop an improved high-temperature-resistant, high-thermal-shock-resistant, low cost honeycomb soot filter compatible with advanced emissions control catalyst technologies that can replace current high-cost and/or uncatalyzed particulate filters.
Among the filter designs being developed for this application are refractory ceramic oxide filters offering improved resistance to high exhaust temperatures encountered during decarbonizing filter regeneration cycles, as well as to the thermal shock conditions arising during rapid filter heat-up and cool-down in the course of startup and regeneration. Two compositions currently being employed for filter construction are cordierite and aluminum titanate. Examples of advanced cordierite and aluminum titanate compositions utilized within honeycomb filter designs being developed for these applications are disclosed in U.S. Pat. No. 6,541,407, entitled CORDIERITEBODY, U.S. Pat. No. 6,849,181, entitled MULLITE-ALUMINUM TITANATE DIESEL EXHAUST FILTER, and U.S. Pat. No. 6,620,751, entitled STRONTIUM FELDSPAR ALUMINUM TITANATE FOR HIGH TEMPERATURE APPLICATIONS, which are each herein incorporated by reference in their entirety. Other materials being employed for refractory, catalyst-compatible ceramic particulate filters are the refractory alkali zirconium phosphates as well as low-expansion alkali aluminosilicates such as beta-eucryptite and pollucite. Many of these same compositions, and other microcracked ceramic materials such as the calcium aluminates, are being considered for use as flow-through catalyst supports for the control of nitrogen oxide (NOx) emissions from automotive and diesel engines.
Advanced aluminum titanate ceramics are among the most promising candidates for use in diesel exhaust filter applications as these ceramics meet or exceed most specifications for high melting point, high thermal capacity, and low thermal expansion. However, one difficulty encountered with these and other porous ceramics intended to function as particulate filters is the need to maintain both high gas permeability and a low coefficient of thermal expansion throughout the processes involved in depositing catalysts on the filter walls. A general requirement is that a low average linear coefficient of thermal expansion (CTE) for these filters should be maintained. Preferably, increases in CTE resulting from the application of washcoats and catalysts should not exceed 10×10−7/° C. averaged over the range from 25-1000° C., and CTE values for the washcoated filters should not exceed 20×10−7/° C. over that same temperature range, in order to preserve the thermal shock resistance of the filter. Further, gas permeabilities through the catalyzed filter should be sufficient to maintain pressure drops below 8 kPa at exhaust gas space velocities up to 150,000 hr−1 after filter regeneration to remove trapped particulates.
A significant drawback associated with the application of the alumina or other washcoating materials typically employed to support the required emission control catalysts is a substantial increase in CTE and reductions in filter permeability. Present understanding is that during the washcoating or catalyzing process both wall porosity of the filter and the structural micro-cracks (crack widths of 0.1-3 microns) that are present in most of these ceramic materials are frequently filled with the washcoating material. This problem is most pronounced in the case of highly microcracked ceramics such as the aluminum titanates, particularly when the washcoating formulations contain materials of very fine particulate size (e.g., particle diameters in the 0.02-0.1 μm range), thereby facilitating the filling of the microcracks with the washcoating material.
Microcracking is a significant contributor to the low CTEs exhibited by many of these materials, with crack closure during heating considerably moderating the dimensional increases that would otherwise occur. As a result, the filling of these microcracks with washcoating constituents can result in some cases in much higher expansion coefficients e.g., in the range of 40-50×10−7/° C., in the washcoated structures. At these CTE levels the risk of structural damage to the filter under the normal conditions of exhaust filter use is unacceptable.
One approach to the problem of washcoat microcrack filling of conventional flow-through catalyst substrates for gasoline engine emissions control has been the use of so-called passivating coatings prior to the application of the associated catalyst. These passivating coatings are pre-coatings applied to the walls of the ceramic substrates prior to the washcoating that can block the washcoating materials from intruding into the microcrack structure of the ceramic. U.S. Pat. No. 4,532,228, entitled TREATMENT OF MONOLITHIC CATALYST SUPPORTS which is herein incorporated by reference in its entirety, provides some examples of coating materials that can be carbonized or otherwise solidified to provide a washcoat barrier, and then removed after the washcoat has been laid down.
To provide adequate protection against CTE increases in highly microcracked ceramics such as aluminum titanates while simultaneously providing an effective guard against unacceptable reductions in ceramic wall gas permeability certain polymeric barrier layers have been employed as the passivation coating. Specifically, these polymeric barrier layers are composed of mainly polymeric materials with hydrophobic and hydrophilic functional groups that are soluble and/or dispersible in a polar medium and that form a neutral or hydrophilic surface on the substrate, at least in the presence of acidic washcoating media. Examples of specific polymer types with these characteristics include ionene polymers, acid-activated aminoacrylate copolymers, and aliphatic acrylic acid copolymers. Another approach employed towards meeting the above-referenced requirements includes applying the passivation polymer barrier layer to the substrate composed of the hydrocarbon polymer, and thereafter over-coating the polymer barrier with an aqueous dispersion of a selected ceramic washcoating material to provide a ceramic-coated substrate. These approaches toward reducing CTE and maximizing the overall ceramic wall gas permeability are disclosed in U.S. patent application Ser. No. 10/641,638, filed Aug. 14, 2003, and entitled POROUS CERAMIC FILTER WITH CATALYST COATINGS, which is incorporated in its entirety herein by reference.
Heretofore, the production processes associated with the manufacturing of low CTE, high gas permeable filters employing the application of passivation and catalyst coatings noted above were time intensive and therefore costly procedures. Specifically, a lengthy drying process of 12 to 24 hours is typically employed subsequent to applying the passivation coating to the filter in order to remove water from the coating. The duration of this drying process is a significant factor with respect to how quickly the filters in process may be moved to the subsequent catalyzing step, and ultimately how quickly the overall process may be completed and filters delivered to the marketplace. Further, an additional drying step is accomplished subsequent to the application of the catalyst coating, thereby further increasing the time of the overall manufacturing cycle. Moreover, the drying processes currently utilized typically include the use of convection ovens that are relatively expensive to operate and maintain, and require a large production area to ensure adequate processing capabilities.
A method for applying and drying passivation coatings and catalyst coatings to ceramic supports and particularly diesel emission filters is desired that protects against CTE increases in highly microcracked ceramics while simultaneously providing an effective guard against unacceptable reductions in ceramic wall gas permeability. Further, the method should also decrease the overall manufacturing time of any given filter by substantially reducing the drying time as required in the process, and should moreover decrease the overall amount of passivation agent required during manufacture, thereby providing an overall cost savings and a reduction to the back pressure associated with the operation of any given filter.

Microwave process for porous ceramic filters with passivation and catalyst coatings


A heavy duty hand tool handle has specifically configured thermoplastic and overmolded elastomeric material, with a thermoplastic grip and thumb receiving recesses for equal right and left hand ergonomic use. Metal indicia are forcibly embedded in the thermoplastic case to provide e.g. safety information which remains legible in long term heavy duty abrasive use.

1. Field of the Invention
This invention relates to hand tool handles. Specifically, this invention relates to hand tool ergonomic handles, particularly including heavy duty use hand tool handles, and more particularly pry bar handles.
2. Background and Discussion of the Prior Art
In general, heavy duty hand tools such as pry bars and wrecking tools are of all metal construction and are cumbersome to grip and use. Often the user has to grip a rectilinear metal portion of the hand tool in use. One such prior art construction is disclosed in U.S. Pat. No. 6,058,809 to Flanz. A wrecking tool is disclosed in U.S. Patent Application Publication No. 2002/0134971 to Christensen. The Christensen heavy duty wrecking tool has an elongated octagonal cross-sectional metal handle or bar stock portion. A non-octagonal handgrip is slidably attached to the octagonal metal bar.
It is generally known to provide a soft elastomeric molded over cover on a molded hard thermoplastic core for improved grip for knives, screwdrivers, and like bladed tools. Such prior art constructions are disclosed in Sanelli, U.S. Pat. No. 4,712,304; Gakhar, U.S. Pat. No. 5,390,572; Hoepfl, U.S. Pat. No. 5,964,009; and Panaccione, U.S. Pat. No. 5,956,799. Generally these handles do not provide sufficient ergonomic character and do not sufficiently accommodate both right and left handed use.
U.S. Pat. No. 6,471,186 and U.S. Pat. No. 6,772,994 granted to Lawless the inventor herein, which Lawless patents are commonly owned with the present application, disclose improvements wherein a metal end cap and pry bar shank are molded into a unitary thermoplastic core, and an elastomeric material is over-molded on the thermoplastic core. A ribbed elastomeric surface was provided in the radially extending distally disposed flange for finger engagement.
Handles that undergo heavy duty or industrial use consequently undergo considerable wear, particularly frictional wear. Where such handles are conventionally imprinted with indicia, the printed indicia would in time wear away and become less legible or illegible. This wear impediment was particularly prevalent in heavy duty tool handles, particularly pry bar handles. Such heavy duty tool handles often require government regulatory safety notices to be imprinted on the handles and remain legible throughout the useful life of the tool.
The hand tool art desires a handle that had long term wear resistant indicia.
The hand tool art also desires an improved ergonomic grip heavy duty handle, particularly with improved ergonomic characteristics equally for both right and left handed users.
It is therefore a principal object of the present invention to provide an ergonomic handle and hand tool.
It is another principal object of the present invention to provide an improved grip hand tool handle having heavy duty wear resistant indicia.
It is another object of the present invention to provide an improved ergonomic handle for a heavy duty hand tool as aforesaid that provides equal ergonomic characteristics for both right and left handed users.
It is still another object the present invention to provide a hand tool handle as aforesaid with diverse functionality.
It is another object of the present invention to provide a hand tool handle as aforesaid for heavy duty pry bar use.
It is still a further object of the present invention to provide a hand tool as aforesaid which is practical in design, manufacture and use.


A cable-base sensor can detect a material level and temperatures of a material stored in a silo. The cable-base sensor comprises an electronic box, a cable, a stopper, and a signal processing module. The electronic box comprises a base and a space for containing the signal processing module, and a hole is formed through a bottom of the electronic box. The base is mounted in the bottom, and a tapered hole is formed through the base. A first end of the cable extents into the tapered hole and the hole, and spreads to form a cable bud. The stopper is a tapered block and pressed into the tapered hole for enforcing the cable bud to be sandwiched between the stopper and the base. The cable bud strengthens a connection between the electronic box and the cable for preventing damages from solid materials.

1. Field of the Invention
The present invention relates to a cable-based sensor, particularly to a cable-based sensor for detecting material level and temperature.
2. Description of the Related Art
For management of bulk material stored in a silo, a sensor for detecting material level is very important. The material level means a height of the material in the silo, and the material level can be converted to obtain the amount of the material stored in the silo. The sensor can be applied to petrochemical industry, food industry, feed industry, steel industry, cement industry, etc. Materials stored in a silo may be solid, liquid, or liquid-solid mixture. For example, the materials may be petroleum, coal, iron sand, cement, flour, cattle fat, etc. When each material is stored in a silo, temperature, moisture and an amount of the material will influence the quality of the materials. In some particular industries, when the temperature of the material stored in the silo is not properly controlled, a dry and dusty material may cause a dust explosion.
When the material is liquid, a conventional sensor can detect temperature, moisture, or material level of the material. The conventional sensor sends magnetic fields produced by voltage-pulses to the material, and detects a feedback of the magnetic fields for calculating the material level. Further, another type of conventional sensor can detect a change between liquid tension of the material and its impedance for calculating the material level.
However, the foregoing conventional sensors cannot detect solid material because detecting cables of the conventional sensors are easily damaged by impacts of the solid material. Therefore, the conventional sensors need to be further improved.

Cable-based sensor for detecting material level and temperature


A cleaning composition comprising: a hydrophobic polymer comprising an organoalkoxysilane; a hydrophilic polymer present in the cleaning composition in an amount ranging from 0.1% to 0.5% by weight based on the total weight of the cleaning composition; a surfactant system; and an acid. A method for cleaning a surface comprising applying the cleaning composition to the surface and retaining the cleaning composition on the surface until it dries.

Cleaning compositions for use on hard surfaces are known in the art. Hard surfaces may include household and outdoor surfaces such as those typically found in bathrooms and kitchens, as well as automobiles surfaces, such as windows and windshields. After cleaning, it is desired to increase the surface's ability to repel water, i.e., increase the surface's water-repellency, as well as to enhance the surface's shine, cleanliness, and ability to protect against material build-up.
It would be desirable to design a cleaning composition that reduces visible residue and increases shine. Acidic cleaners are known that purport to provide activity against mineral deposits, such as lime scale or soap scum, and also for rust removal. Some cleaners are marketed as being useful for cleaning glass surfaces in that they may reduce streaking or the build-up of dirt and dust, and they may provide anti-fog and/or anti-rain benefits (e.g., water-repellency). It is desirable that the beneficial effects of the cleaning composition be long-lasting, so that the consumer does not have to repeat the cleaning process frequently. It is also desirable that a cleaning composition is functional under harsh conditions, such as with exposure to acid rain, heat, cold, and dust.
Prior known cleaning compositions sometimes contained phosphate salts. In view of the environmentalist's efforts to reduce phosphate levels in ground water, improved all-purpose liquid cleaners containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. However, these prior art liquid cleaning compositions containing detergent builder salts or other equivalents tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquid cleaning compositions require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
Therefore, the need exists for a cleaning composition that provides water-repellency to a surface and is effective to remove soil while leaving the surface shiny, as well as prevent the formation of soil spots, lime scale, and buildup over an extended period of time.

Cleaning composition to provide long-lasting water repellency on surfaces


A surgical microscope (100) for ophthalmology includes a measuring unit (110) for determining at least one characteristic value of a patient eye (104). The measuring unit (110) is connected to a computer unit (120) which calculates a model of the patient eye (104) based on the determined characteristic variables. The surgical microscope also includes a display device for displaying the calculated model of the patient eye (104) or characteristic variables that are derived from the calculated model.

The geometric length between optically effective surfaces of the eye is understood to be included in the optical characteristic variables of an eye of a patient whereat a jump or a non-vanishing gradient of the index of refraction occurs or whereat an absorption of light takes place. The local radii of the surfaces, that is, their Gaussian curvatures can, however, likewise be considered as optical characteristic variables of an eye of a patient. An optical characteristic variable of a patient eye is, inter alia, also the refractive index or the refractive power of an optically effective component thereof.
A surgical microscope of the kind referred to above is disclosed in U.S. Pat. No. 6,004,314. Here, a surgical microscope is described having a coherence interferometer in the form of an OCT measuring unit. This OCT measuring unit provides an OCT scanning beam which can be scanned in a transverse direction across the cornea of a patient eye to determine the thickness thereof and to measure the precise course of the forward surface of the cornea and the rearward surface thereof.
United States patent publication 2003/139736 A1 discloses an ophthalmologic surgical microscope having an integrated refractometer. With the aid of this refractometer, the optical characteristic of an artificial eye lens, which is placed during cataract surgery, can be monitored during the course of the surgical procedure so that it is possible to correct the artificial eye lens as required.
U.S. Pat. No. 5,828,439 discloses a refractometer with which the refractive power of the human eye can be determined during a surgical procedure. A measuring unit is integrated into this refractometer for measuring a non-optical characteristic variable of the eye in the form of the inner pressure of eye. This inner pressure is used to correct a measured refractive power value.
German patent publication 4,310,561 discloses an arrangement for determining refraction and visual acuity during a surgical procedure on the human eye. This arrangement permits imaging a test card on the retina of the eye of the patient which is illuminated by means of a light source and which is suitable for measuring an imaging sharpness of the eye. When the physician detects with the arrangement a sharp test card image on the retina of the patient eye, then an absolute refraction value for the eye being examined can be determined from the apparatus parameters of the arrangement. The device is combined with a surgical microscope and, in turn, permits a physician to make a refraction determination during the course of a surgical procedure when viewing the eye of the patient.
An arrangement for analyzing and correcting the refractive power of a human eye is described in European patent publication 0,247,260. The arrangement includes a data store wherein data of an idealized patient eye are stored for the following: different axial eye lengths; patient age; sex; and, also values for the inner pressure of the eye. In this arrangement, means are provided for determining the particular corneal topography. The arrangement further includes a laser unit with which incremental amounts of the cornea of the human eye can be removed. The removal is so adjusted that a desired topography of an idealized patient eye results. The development of cataract surgery to an ever more careful surgical technique accompanying refractive surgery of the cornea has led to an increase in the demands on the optical characteristic of the patient eye after cataract surgery. It is expected that the full visual acuity is achieved without correcting spectacles.
In addition, in ophthalmologic surgery, it is attempted to correct for reduced visual capacities of the human eye when the pupil width of the eye is greater than 2 mm. These visual deficiencies are caused by the geometric optical correction of the eye which is by nature inadequate. Here it is sought, for patients with average or below average vision, to assist these patients in obtaining an above average visual acuity (that is, >1) via intervention into the optical characteristics of the human eye. This above average visual acuity occurs only in exceptional cases in humans.
Finally, in ophthalmologic surgery, efforts are being made to reverse the reduction of the accommodative power of the human eye because of age which is the so-called presbyopia. Since the effectors of the accommodation are the so-called ciliary muscles, there is a way to improve the accommodative power of the eye in older persons in that the aging natural lens of the eye is exchanged for an artificial lens.
With this as background, it is desirable and necessary for ophthalmologic surgery that the refractive state of a patient eye after surgery can be predicted as precisely as possible, especially the state in the eye interior and the state of the eye lens. For such a prediction, precise optical measurement methods are known and can, for example, be carried out with the IOL Master of Carl Zeiss Meditec AG in the context of a preoperative characterization of the eye.
However, in the present state of cataract surgery, only an intraocular lens is inserted which is selected based on preoperative data. The healing of the wound of the eye is then awaited during which the optical characteristic variables often change such as the distance of the refractive components of the eye. Only after the completion of the healing of the wound do the optical characteristics of the eye stabilize.
In the context of this background, it is desirable to control the optical characteristics of the eye also during surgery to be able to rapidly recognize an unwanted deviation from the preplanned state so that the surgery can be modified as required. Furthermore, there are now surgical techniques (for example, injectionable intraocular lenses) which make it necessary to compensate optical characteristics of the eye during a surgical procedure. Up to now, it is only known in the state of the art to intraoperatively measure a single optical variable of the eye, for example, the refractive power thereof. However, the optical state of the eye cannot be reliably determined on the basis of this single optical characteristic variable. It has been shown that, in the course of a healing process after a surgical procedure on the eye, not only a single optically effective variable changes but a modification of several optical characteristic variables of the eye takes place whose optical effect possibly partially amplifies but also mutually weakens.
The human eye is an optical system which, as a rule, is far from perfect. In a perfect eye, which is also characterized as an emmetropic eye, light rays, which originate from a point in an object region, converge in the eye interior at a point which lies on the retina of the eye. However, in reality, this state never occurs. On the one hand, this is caused by the fact that an optical system, which has a limited aperture, images a mathematical point (whose diameter is zero), because of the diffraction of light, on a point whose diameter is greater than zero. On the other hand, this is caused by the situation that the optical components of the eye, namely cornea and lens, are far from perfect. When the curvature of the cornea is too great or the eye is too long, then the image of the object lies in a plane which is forward of the retina. This leads to the situation that the object is observed by the eye as being blurred. The corresponding vision defect is known as myopia. For the opposite situation, when the cornea is too flat or the eye is too short, the image, which is imaged by the eye, lies behind the surface of the retina. Again, an observed object appears blurred. This vision defect is known as hyperopia. Finally, a third vision defect is called astigmatism and this is caused by the optical areas in the eye having a certain elasticity. This elasticity has the consequence that, with the human eye, it is not at all possible to image a point precisely as a point. Rather, the best possible image of a point that the eye can generate is an ellipse.
Ophthalmologists and opticians know the vision defects listed. They can correct these vision defects with the aid of spectacles and contact lenses. It is also possible to undertake a vision defect correction with a surgical procedure on the eye, for example, by inserting a phakatic intraocular lens in the eye or via the so-called photo-refractive keratomileusis (PRK).
To improve an operative correction of visual defects, it is desirable to detect the condition of the eye during a surgical procedure thereon before, during and after a surgical procedure. Up to now, for example, in cataract surgery, an intraocular lens is inserted into the patient and the form of this lens is determined from preoperatively obtained patient data. In surgery, the optical characteristics of the eye on which surgery is performed cannot be monitored. This is problematic because, during the course of surgery, and during a healing of the wound, optical characteristic variables of the eye can change such as distances of refractive elements.
When it is possible to control the optical characteristics of the eye also during a surgical procedure, an unwanted deviation from a preplanned state can be rapidly detected and adapted or modified during the surgical procedure. In surgical procedures for reestablishing the accommodation while utilizing injectionable intraocular lenses, a compensation of the optical character of intraocular lenses and patient eyes are indeed necessary.

Ophthalmologic surgical microscope having a measuring unit


Disclosed herein are a novel complex metal oxide catalyst, and a method of preparing polyester using the same. The metal-bound compound of the present invention has a higher catalytic activity as compared to an antimony catalyst and existing titanium catalysts to be easily synthesized and stabilized, have a sufficient polymerization activity even with a small amount, and be used as an environmentally friendly catalyst for polyester polymerization. In addition, when preparing polyester by using the complex metal oxide of the present invention, since catalytic activity caused by phosphorus (P) which is a thermal stabilizer used to decrease pyrolysis at the time of hot-melting and molding is not deteriorated, an excessive amount of phosphorus may be used as compared to the related art, such that pyrolysis less occurs, whereby the yellowing phenomenon may be decreased and high viscosity may be maintained. Therefore, the complex metal oxide may be usefully applied to the preparation of polyester having good physical properties, in particular, polyethylene terephthalate.

(a) Field of the Invention
The present invention relates to a complex metal oxide, and a method of preparing polyester using the same. More particularly, the present invention relates to a complex metal oxide including three kinds of metal and having a stabilized structure to be capable of being used as a catalyst for polyester polymerization, and a method of preparing polyester using the same.
This application claims the benefit of Korean Patent Application No. 2012-0038477 filed in the Korean Intellectual Property Office on Apr. 13, 2012, the entire contents of which are incorporated herein by reference.
(b) Description of the Related Art
Polyester has been applied to various fields, for example, a beverage filling container, a medical packaging material, a sheet, a film, and a car molded product which have been applied from the related art, due to excellent mechanical properties and chemical properties. Representative example thereof includes polyethylene terephthalate. The polyethylene terephthalate has been widely used due to excellent physical and chemical properties, dimensional stability, and the like, and is mainly prepared by using an antimony (Sb)-based catalyst.
However, in the case of products manufactured by the antimony-based catalyst, a large amount of antimony needs to be used in polymerization process, and the antimony itself has toxicity, such that at the time of using the products for a long time, the antimony may leak and may be introduced in vivo, causing deterioration of fetal growth, diseases such as carcinogenicity, and the like, and leading to environmental problems (Appl. Polym. Sci. 2004, 92, 1887). In accordance with the recent research results, it is known that even in a drinking water bottle, and a food packaging material manufactured by using the antimony catalyst, a large amount of antimony causing toxicity in vivo is detected (J Environ. Monit. 2006, 8, 288). Accordingly, in some advanced countries, regulation or ban on the use of the antimony-based catalyst has gradually proceeded, and an environmentally friendly catalyst capable of substituting for a toxicity-inducing metal such as antimony has been developed.
Regarding this, methods of using a metal compound capable of substituting for a highly toxic antimony-based catalyst, and having a low toxicity in vivo, and known as being environmentally friendly, as a catalyst for polyester polymerization, have been suggested.
For example, International Publication Patent No. WO95/018839 discloses a catalyst preparing polyester and copolyester by using TiO2/SiO2 or TiO2/ZrO2 oxide coprecipitate. In addition, Japanese Patent Laid-Open Publication No. 2003-40991 suggested a method of polymerizing polyester by using a complex oxide such as TiO2/Al2O3, TiO2/SiO2 or TiO2/ZrO2 as a catalyst.
However, the catalysts used in the above-described methods have a limitation in that a small amount of phosphorus (P) should be used as an additive serving as a thermal stabilizer and an antioxidant used in the polymerization process of the polyester, such that during the melting and molding process, it is easy to cause pyrolysis, oxidation degradation and a yellowing problem of polyester. Therefore, at the time of manufacturing a film and a drinking water container using the polyethylene terephthalate polymerized by using the existing complex oxide catalyst, since the yellowing problem occurs, the product has a darkened brightness, which is not appropriate for commercialization. In addition, since activity of the catalyst itself is not controllable in the polycondensation, polymer having a large distribution of molecular weight is prepared, such that it is difficult to obtain polyester having a desired viscosity in a solid phase polymerization.
Therefore, development of a catalyst capable of being environmentally friendly and stabilized with phosphorus, and having few problems such as pyrolysis, oxidation degradation, and yellowing problem at the time of utilizing molded products manufactured by using a resin obtained by polyester polymerization using the catalyst, has been still demanded.

Complex metal oxide, and method of preparing polyester using the same


An interactive education system for teaching patient care to a user is described. The system comprises a patient simulator; a virtual instrument for use with the patient simulator in performing patient care activities; means for sensing an interaction between the virtual instrument and the simulator, and means for providing feedback to the user regarding the interaction between the virtual instrument and the simulator.

The present embodiment relates generally to an interactive education system for teaching patient care, and more particularly to such a system having virtual instruments for use with a child birthing patient simulator in conducting patient care activity.
While it is desirable to train students in patient care protocols before allowing contact with real patients, textbooks and flash cards lack the important benefit to students attained from "hands-on" practice. Thus, patient care education has often been taught using medical instruments to perform patient care activity on a simulator, such as a manikin. However, one disadvantage of such a system is that medical instruments are often prohibitively expensive, and consequently, many users must settle for using a smaller variety of instruments, even at the cost of a less comprehensive educational experience. One solution to the foregoing problem is using a set of relatively inexpensive, simulated medical instruments ("virtual" instruments), as taught in U.S. Pat. No. 5,853,292, the entire disclosure of which is hereby incorporated by reference.
Another problem in patient care education is that the patient simulators used for teaching a user are generally passive. For example, in a child birthing simulation, a user must position the simulated fetus in a simulated maternal pelvis, move it down the birth canal, birth the fetus's head, rotate the fetus approximately ninety degrees to birth the shoulders, and finally, pull out the fetus, now referred to as a neonate. While replicating the sequence of events in a real delivery, the lack of verisimilitude resulting from physical manipulation of the fetus by the user undermines an appreciation for the difficulties of providing patient care. In a real delivery, the fetus is inaccessible, and most activity is obscured from view, and thus prior systems fail to address the most challenging conditions of providing patient care during child birthing. Moreover, prior systems fail to simulate cervical dilation as the fetus moves down the birth canal, thus failing to allow a student to assess the stage of delivery or construct a chart of cervical dilation versus time to assess the progress of delivery ("Partograph").
Therefore, what is needed is a system for an interactive education system for use in conducting patient care training sessions using relatively inexpensive virtual instruments in cooperation with a more realistic simulated patient, thereby enabling a user to learn comprehensive multiple and interrelated patient care skills.

Interaction education system for teaching patient care


A prosthesis for correcting urinary stress incontinence in women including right and left para-urethral hemi-prostheses, each of the hemi-prostheses formed of a biocompatible material and in the form of a strip, one end of the strip having a bulged portion and another end of which is adapted to be attached to the aponeurosis of the rectus muscle of the abdomen, and means for attaching the another end to the aponeurosis of the rectus muscle of the abdomen.

Urinary stress incontinence is a pathology occurring most often after obstetric trauma. The ligaments supporting the bladder often become distended and the bladder is pushed downwardly and out of the pelvic cavity which normally supports it. The angle of the bladder at the level of the bladder neck is opened and—upon an effort such as sneezing—the urethra, which is no longer protected by the pelvic cavity, is subjected to the totality of the pressure generated by the stress and an incontinence phenomenon occurs.
This phenomenon has been well known and various solutions have been attempted. WO 00/15140 discloses an intra-urethral prosthesis. EP-A-498912 discloses a sub-urethral prosthesis designed to be implanted for a limited period of time at the level of the vagina. FR-A-2787990 discloses a prosthesis constituted of two right and left hemi-prostheses, each hemi-prosthesis comprising a net attached to the vaginal wall on which is anchored a thread the other end of which is attached to the base of the rectus muscle of the abdomen. The net is a sub-urethral element on which the bladder neck rests.
The prostheses of the prior art represent a certain number of risks for the patient, notably the risk of tearing of the bladder or damage caused to the bladder neck or the urethra when the prosthesis is installed. Sub-urethral materials also have drawbacks in use by preventing or restricting miction.

Implantable prosthesis for correcting urinary stress incontinence in women


In a method for producing a semiconductor device, a first semiconductor layer is epitaxially grown on a semiconductor substrate, an insulating film pattern is formed on the first semiconductor layer, and portions of the first semiconductor layer are removed by wet etching using the insulating film pattern as a mask to leave a ridge having a reverse mesa shape and a width. Ends of the insulating film pattern are removed by etching to approximately the width of the ridge, a second semiconductor layer is epitaxially grown on opposite sides of the ridge, and a third semiconductor layer is epitaxially grown on the ridge and the second semiconductor layer. The second semiconductor layer is evenly grown without concave portions at opposite sides of the ridge. In addition, the third semiconductor layer is evenly grown on the ridge and the second semiconductor layer, and an electrode reliably connects the surface of the third semiconductor layer. A semiconductor device with good performance and high reliability is reproducibly manufactured.

FIG. 17(a) is a cross-sectional view showing a prior art ridge waveguide type semiconductor laser device. In FIG. 17(a), reference numeral 400 designates an n type GaAs series semiconductor laser device. An n type AlGaAs first cladding layer 2 is disposed on the n type GaAs substrate 1. A p type AlGaAs active layer 3 is disposed on the n type AlGaAs first cladding layer 2. A p type AlGaAs second cladding layer 4 having a ridge in a reverse mesa shape is disposed on the p type AlGaAs active layer 3. A p type GaAs first cap layer 5 is disposed on the ridge of the second cladding layer 4. An n type GaAs current blocking layer 8 and a p type GaAs second cap layer 50 are disposed at both sides of the ridge. A p type GaAs contact layer 9 is disposed on the p type GaAs second cap layer 50. A p side electrode 10 and an n side electrode 11 are disposed on the p type GaAs contact layer 9 and the rear surface of the n type GaAs substrate 1, respectively. FIG. 17(b) shows an n type GaAs semiconductor laser device having the same structure as the device of FIG. 17(a), in which the p type GaAs contact layer 9 is thicker than that of FIG. 17(a).
A description is given of the production method. FIGS. 18(a)-18(e) illustrate process steps in a method for producing the semiconductor laser shown in FIG. 17(a). Initially, as illustrated in FIG. 18(a), there are successively grown on the n type GaAs substrate 1 the n type AlGaAs first cladding layer 2, the p type AlGaAs active layer 3, the p type AlGaAs second cladding layer 4, and the p type GaAs first cap layer 5 (first epitaxial growth step). Preferably, these layers are grown by metal organic chemical vapor deposition (MOCVD).
Then, as illustrated in FIG. 18(b), an SiN film 6 and a photoresist 7 are successively deposited on the first cap layer 5, and the SiN film 6 is patterned in a stripe shape by conventional photolithographic and selective etching steps.
Then, as illustrated in FIG. 18(c), after removing the photoresist 7, the p type AlGaAs second cladding layer 4 and the p type GaAs first cap layer 5 are selectively removed by wet etching using the SiN film 6 as a mask, leaving a ridge having a reverse mesa shape. The wet etching should be carried out so that the p type AlGaAs second cladding layer 4 remains on the p type AlGaAs active layer 3 at opposite sides of the ridge.
Subsequently, as illustrated in FIG. 18(d), the n type GaAs current blocking layer 8 and the p type GaAs second cap layer 50 are successively grown on the p type AlGaAs second cladding layer 4 to bury the ridge, preferably by MOCVD (second epitaxial growth step).
After removing the SiN film 6, the p type GaAs contact layer 9 is grown on the p type GaAs first cap layer 5 and the p type GaAs second cap layer 50, preferably by MOCVD (third epitaxial growth step). Thereafter, the p side electrode 10 and the n side electrode 11 are formed on the p type GaAs contact layer 9 and the rear surface of the n type GaAs substrate 1, respectively, completing the semiconductor laser device 400 shown in FIG. 18(e). If the p type GaAs contact layer 9 is grown thick in the third epitaxial growth step, the laser structure shown in FIG. 17(b) is obtained.
In operation, when a forward bias voltage is applied across the n type GaAs substrate 1 and the p type GaAs contact layer 9, current flows into the p type AlGaAs active layer 3 through the ridge having a reverse mesa shape and carriers are confined in the p type AlGaAs active layer, resulting in carrier recombinations that produce laser light. At this time, since light absorption and current concentration are caused by the n type GaAs current blocking layer 8, a difference in refractive index along in the horizontal direction of the active layer 3, restricting the extent of the generated light in the transverse direction. Thus guided light resonates in a Fabry-Perot resonator which is constituted by cleavage facets opposite to each other in the longitudinal direction of the stripe-shaped ridge, and laser oscillation occurs.
The conventional ridge waveguide type semiconductor laser device has the following drawbacks.
FIG. 19 is a sketch of an electron microscope photograph illustrating a cross-section of the wafer after the second epitaxial growth step shown in FIG. 18(d). During the selective etching for forming the ridge structure having a reverse mesa shape, portions of the cap layer 5 beneath the ends of the SiN film 6 serving as an etching mask are unfavorably etched away, resulting in over-hanging portions 6a. This is caused by poor adhesion between the etching mask, comprising SiN or the like, and the epitaxially grown layer so that the etchant permeates into the interface between them. If such over-hanging portions 6a are present in the second epitaxial growth step, i.e., the step of successively growing the n type GaAs current blocking layer 8 and the p type GaAs second cap layer 50 on the p type AlGaAs second cladding layer 4, reactive gases do not reach the over-hanging portions 6a, resulting in an uneven growth that produces hollows 21.
When the SiN film 6 is removed and the p type GaAs contact layer 9 is grown on the first and second cap layers 5 and 50 by the third epitaxial growth step, concave portions are formed on the surface of the contact layer 9. In addition, since the crystal growth is unevenly carried out beneath the over-hanging portions 6a, crystallinity of the p type GaAs contact layer 9 disposed thereon is poor, adversely affecting performance of the semiconductor device. In addition, if concave portions are formed on the p type GaAs contact layer 9, a metal film, serving as a p side electrode 10, is not evenly deposited on the contact layer, resulting in an unreliable device. Especially when the p type GaAs contact layer 9 is thin as shown in FIG. 17(a), the p type GaAs contact layer 9 is unfavorably broken due to the concave portions between the p type GaAs first cap layer 5 on the ridge and the p type GaAs second cap layer 50, and the p side electrode 10 on the contact layer 9 is also broken, resulting in further reduction in reliability of the device.
If crystallinity of the epitaxially grown layer, which is regrown at opposite sides of the ridge, deteriorates, the thickness of the epitaxially grown layer is not even and the ridge unfavorably protrudes. In this state, when the p type GaAs contact layer 9 is formed, a convex portion is formed on the surface of the p type GaAs contact layer 9 and a stress is applied to the ridge in the subsequent steps, such as a step of polishing the rear surface of the substrata, a step of mounting the semiconductor chip on a package with solder while connecting the ridge side to a heat sink (junction down), and the like, whereby the ridge is damaged. In addition, the convex portion of, a, the contact layer does not adhere closely to the heat sink, causing an inclination of a laser beam produced by the chip.
Meanwhile, Japanese Published Patent Applications Nos. 63-269593 and 1-287980 and Mitsubishi Denki Giho Vol.62, No. 11 (1988), pp.958 to 961 propose ridge waveguide type semiconductor laser devices in which a p type AlGaAs buffer layer or a p type GaAs buffer layer is grown on a p type AlGaAs cladding layer exposed at both sides of a ridge and then an n type GaAs current blocking layer is grown. In these laser devices, since the crystal growth of the p type AlGaAs or GaAs buffer layer smoothly progresses on the p type AlGaAs cladding layer, the crystal layer is grown to some degree beneath the above-described over-hanging portions. However, it is impossible to completely fill up the hollows under the over-hanging portions, so that the above-described problems have not been completely solved yet.
FIG. 21 is a graph showing oxygen concentrations determined by SIMS analysis in the p type AlGaAs second cladding layer 4 and the n type GaAs current blocking layer 8 produced in the process steps shown in FIGS. 18(a)-18(e). Since the surface of the p type AlGaAs second cladding layer 4 is exposed to the atmosphere during the etching for forming the ridge, much oxygen exists on the surface of the cladding layer 4. As the result, an interface level is produced between the cladding layer 4 and the current blocking layer 8 in a completed device, and leakage current generated in this region, deteriorating characteristics of the device.
When the ridge is formed by wet etching, fine grooves are formed on the exposed surface of the p type AlGaAs second cladding layer 4. The depth of each groove is equal to a thickness of several atom layers, i.e., 10 to 20 angstroms. When the n type GaAs current blocking layer 8 is epitaxially grown on the p type AlGaAs second cladding layer 4, since the n type GaAs does not favorably match with the p type AlGaAs, the grooves also appear on the surface of the n type GaAs current blocking layer 8, whereby crystallinity of the current blocking layer 8 deteriorates, resulting in deterioration in the device characteristics.
As a solution of the above-described problem, there is a method for producing a ridge waveguide type semiconductor laser device disclosed in Japanese Published Patent Application No. 64-84780. In this method, after a ridge is formed by wet etching, the surface of a first semiconductor layer exposed at both sides of the ridge is etched by vapor phase etching in a reaction tube, and a second semiconductor layer is grown on the first semiconductor layer in the same reaction tube. In this case, although the concentration of oxygen on the crystal surface is reduced and the grooves generated on the crystal surface due to the wet etching are decreased, since the vapor phase etching and the crystal growth are carried out in the same reaction tube, reaction products of the vapor phase etching adversely affect the crystal growth, resulting in poor crystallinity of the grown layer.
FIGS. 20(a)-20(c) are cross-sectional views of process steps in a method for dividing a semiconductor substrate, on which a plurality of p type InP ridge waveguide semiconductor laser elements are disposed, into a plurality of semiconductor laser devices. In the figures, semiconductor laser elements 19 and 20 are adjacent to each other on a p type InP substrate 12. In each semiconductor element, a ridge 22 is formed in the substrate 12 and an undoped InGaAsP active layer 14 is formed in the ridge 22. An InP epitaxial layer 13 is disposed on the p type InP substrate 12 at opposite sides of the ridge 22. An SiO.sub.2 film 15 is disposed on the entire surface except for the center of the top surface of the ridge 22. An n side electrode 16 is disposed on the ridge 22 and the SiO.sub.2 film 15. Reference numeral 18 designates an interface between the p type InP substrate 12 and the InP epitaxial layer 13 and numeral 17a (17b) designates a photoresist.
First of all, as illustrated in FIG. 20(a), a photoresist 17a is deposited on the entire surface of the p type InP substrate 12, on which the semiconductor elements 19 and 20 are present, and patterned to form a stripe groove approximately 5 microns wide between the elements 19 and 20. Then, using the photoresist 17a as a mask, the SiO.sub.2 film 15 is etched away to expose the surface of the epitaxial layer 13.
Then, as illustrated in FIG. 20(b), using the SiO.sub.2 film 15 as a mask, the InP substrate 12 and the epitaxial layer 13 are wet etched using an etchant including hydrochloric acid to form a groove 21 deeper than the interface 18. In this case, hanging portions 15a about 2 microns formed on both ends of the groove 23 because of the side etching of the layers 12 and 13. If the wafer is divided without removing the over-hanging portions 15a, SiO.sub.2 powder is produced and adheres to the pn-junction exposed on the cleavage plane of the separated element, causing a leakage current. Or, the over-hanging portions of the SiO.sub.2 film 15 come off, adversely affecting the characteristics and reliability of the laser device.
In order to avoid this problem, the over-hanging portions 15a may be removed before the division of the wafer. More specifically, after removing the photoresist 17a, a photoresist 17b is deposited on the entire surface of the wafer and patterned to form an aperture of approximately 30 microns width above the groove 21. Using the photoresist 17b as a mask, the over-hanging portions 15a of the SiO.sub.2 film 15 are etched away by an etchant including HF as shown in FIG. 20(c). Finally, the p type InP substrate 12 is cut along the groove 21 to separate the semiconductor laser elements 19 and 20 from each other.
In this method, however, the step of removing the over-hanging portions 15a is very complicated. In addition, since it is difficult to precisely remove only the over-hanging portions 15a, the end surface of the InP epitaxial layer 13 is unfavorably exposed, resulting in deterioration in the device characteristics.

Method for producing semiconductor device


A coordinated brake control system is for a hybrid brake system including a regenerative brake unit and a friction brake unit for a vehicle and is arranged to generate a total braking torque which is a combination of a regenerative braking torque generated by the regenerative brake unit and a friction braking torque generated by the friction brake unit, so as to bring the total braking-torque closer to a target braking torque, and to limit a rate of change of the regenerative braking torque according to a response delay of the friction braking torque when a first distribution ratio of the generative braking torque relative to the total braking torque is decreased and when a second distribution ratio of the friction braking torque relative to the total braking torque is increased.

The present invention relates to a coordinated brake control system of a hybrid brake system having a regenerative brake unit and a friction brake unit, and more particularly to a coordinated brake control system which is capable of smoothly transiting a braking from a regenerative braking to a friction braking.
Japanese Patent Provisional Publication No. 2000-225932 discloses a coordinated brake control system which is arranged to calculate a target barking torque according to vehicle driving and traveling conditions and to achieve the target braking-torque by a combination of a regenerative braking and a friction braking of a hybrid brake system. The hybrid brake system comprises a regenerative brake unit which generates a braking torque by converting a wheel rotating energy into electric power using a motor/generator and a friction brake unit which generates a braking torque by hydraulically or electro-magnetically operating a friction brake device.
When this coordinated brake control system generates a master cylinder hydraulic pressure Pmc at a moment t2 in FIGS. 12A through 12E in reply to the depression of a brake pedal, a regenerative braking-torque is mainly produced for a period of a relatively high vehicle speed range from the moment t1 to a moment t2 during when it is possible to accurately execute the regenerative braking so as to improve a fuel consumption by improving an energy recovery rate while suppressing a friction braking torque. Thereafter, when vehicle speed VSP becomes a relatively low vehicle speed at the moment t2 and later, the regenerative braking-torque command value is gradually decreased according to the lowering of the vehicle speed VSP as shown by a continuous line in FIG. 12C, and simultaneously a braking hydraulic pressure command value corresponding to friction braking torque is gradually increased as shown by a dot and dash line in FIG. 12D. Finally, all of the braking becomes dependent on the friction braking torque at a moment t3, and the coordinated brake control is terminated at the moment t3.
This coordinated brake control system is arranged to keep a decreasing rate for decreasing the regenerative braking torque at a constant rate. Accordingly, even if the decreasing rate is varied, there is still caused the following problem at the moment t2 and adjacent thereof when a gradual decreasing of the regenerative braking torque is started. That is, the friction braking system poorly performs a responsibility of generating the braking-torque in reply to the received signal as compared with that of the regenerative braking system, and therefore the rising of the brake hydraulic pressure at a start from zero largely delays as compared with the standard response shown by a broken line determined based on the brake hydraulic pressure command value.
This delay of the initial rising causes a large difference between the standard response and the actual response of the hydraulic pressure during an early period of the hydraulic pressure rising. Although the actual hydraulic pressure is then quickly risen by the execution of a feedback control based on the difference so as to follow up the standard response as shown by a continuous line in FIG. 12D, the difference during the early period of this transition stage shown by hatching in FIG. 12D generates a shortage of the hydraulic pressure, and therefore there is a possibility that a driver has an impression that the transition from the regenerative braking to the friction baking is not smooth.

This patent is subject to a terminal disclaimer.