A high-power laser system includes a laser master oscillator, a plurality of fiber laser amplifiers producing intermediate output beamlets, a diffractive optical element for combining the intermediate beamlets into a combined output beam, and one or more error controllers for minimizing errors related to beam combination that may degrade the quality of the combined output beam. A piston error controller uses phase modulation to tag each non-reference intermediate beamlet with a unique dither signal harmonically unrelated to those used for the other beamlets. For each intermediate beamlet, the associated piston error is recovered using a synchronous detector, and an error control signal proportional to the piston error is supplied to a phase modulator to control the piston error for that beamlet. A tilt error controller uses amplitude modulation based on Hadamard code words to tag each non-reference intermediate beamlet with a unique code sequence orthogonal to those used for the other beamlets. For each intermediate beamlet, the associated tilt error is recovered using a Hadamard decoder, and an error control signal proportional to the tilt error is supplied to a beam steerer to control the tilt error for that beamlet.

Optical fiber laser amplifiers are a known technology for producing a coherent output beam of intermediate power. A variety of factors, including Stimulated Brillouin Scattering, four wave mixing, and optical damage, limit the output power of a single fiber amplifier to the range of several hundred W. Although a laser of this power output may be useful in a variety of applications, other applications require higher output power than that available from a single fiber amplifier.
Higher powered laser systems have been constructed by assembling an array of fiber amplifiers driven by a master oscillator. The output beams from each of the fiber amplifiers are combined to produce a nominally single output beam. In general, in order for the combined beam to have good beam quality, the individual beams must be substantially parallel and collinear.
A variety of approaches have been used to combine the beams from multiple fiber amplifiers. Most of these employ lenses and prisms. One known approach employs a lenslet array, a precision-manufactured array of small lenses, typically on a single substrate, to combine the several beams into a single powerful beam.
The use of a lenslet array to combine the beams from several fiber amplifiers has several disadvantages. Systems using a lenslet array are difficult to align. Also, the lenslet array substantially attenuates each of the individual beams, because the individual beamlets unavoidably overfill the lenslet aperture and the interstitial space between the lenslets does not act as a lens. This insertion loss is sometimes referred to as a "fill-factor" power loss, and robs some of the output power of the amplifier array. The power lost in the lenslet array results in heating. It may therefore be necessary to cool the lenslet array. In addition, the lenslet array imprints the far-field pattern of the combined output beam with the Fourier transform of the lenslet array. This results in a loss of beam quality.
A diffractive optical element (DOE) may also be used to combine the beamlets from several fiber amplifiers into one output beam. A DOE is a special type of grating having a grating surface shape (i.e., grooves) constructed according to a particularly designed grating function. A DOE differs from a conventional grating in that the DOE grating is coarser (i.e., the spatial frequency of the grooves of the DOE is much lower), and the shape of the grooves in the DOE surface is important. The product of the grating groove frequency and the light wavelength of the beamlets to be combined defines a characteristic angle, or "eigenangle" measured with respect to the grating normal. Each beamlet to be combined by the DOE must impinge on the grating precisely at a multiple of the characteristic angle if the single combined beam is to have good beam quality and if no exiting satellite beamlets at other than normal incidence to the DOE are to be created. Moreover, the optical phase of each beamlet, measured relative to a central beamlet impinging normal to the DOE surface must either be zero or pi radians according to a certain recipe, in order that no exiting satellite beamlets are to be produced and that the central emerging beam have good beam quality. Deviation from this condition is termed "piston error".
It is preferable that all of the energy exiting the DOE beam combiner be concentrated into a single beam or lobe. Two factors controlling whether this occurs are: (1) phase or "piston" error, defined above, and (2) "tilt" error, whereby one or more beamlets are incident on the DOE at angles which deviate from the aforementioned eigenangles, the values of which are determined by the grating function and the wavelength of the light being combined.
If either piston error or tilt error are present, unwanted secondary beamlets or lobes appear at the exit of the DOE. The beamlets are oriented along eigenangles or exit "orders", again determined by the grating function and the wavelength of the light being combined as described above. This is undesirable because the secondary beamlet generation reduces power and beam quality in the central lobe. In addition, if enough energy is present in the secondary beamlets, the stray beamlets may heat or damage objects or equipment.
Thus, the need exists for a laser system having a plurality of fiber laser amplifiers, each producing an intermediate beamlet, and a diffractive optical element that combines the intermediate beamlets to form an output beam, which laser system substantially minimizes piston error and tilt error with respect to the beamlets incident on the diffractive optical element.

Error control for high-power laser system employing diffractive optical element beam combiner


The present invention provides an improved Digital to Analog Converter (DAC) of the switched dual string DAC type, which saves on chip surface area, reduces the number of resistors and implementation cost, reduces the self capacitance and the device leakage currents of the circuit elements. The invention provides a guaranteed monotonic DAC architecture, which comprises a switching network for creating three states at a DAC transition node. In one embodiment the invention provides an unloaded state wherein a LSB DAC is de-coupled from a MSB DAC wherein the node between neighboring MSB DAC resistors is coupled to the DAC output. One of the advantages of creating the unloaded state is that the number of LSB DAC resistors is reduced as is normally the case in the prior art for a similar application.

As is known in the art, DACs have been used in a wide variety of applications to convert an N-bit digital word into a corresponding analog signal. One such DAC includes a string of 2N resistors having substantially the same resistance serially connected across a reference voltage. Thus, the resistor string divides the reference voltage among the resistors in the string. A switching network is provided for coupling the voltage at one of the resistors to an output to produce the converted voltage. While such a DAC is suitable for applications where N is relatively small, when N is large, for example, where N is in the order of twelve, 4,096 resistors, 4,096 switches, and 4,096 control lines are required thereby resulting in a relatively large number of elements to be fabricated on an integrated circuit chip.
One technique suggested to reduce the number of elements is to use a segmented converter. In a segmented converter, a first stage uses a resistor string for converting a group of higher order bits of the N-bit digital word and a second stage decodes the remaining, lower order bits. A non-linear converter of that general type is shown in an article by Gryzbowski et al., entitled "Non-liner Functions from D/A Converters", Electronic Engineering 1971, pgs. 48–51. The converter disclosed in that article is designed for operation with relay switching and is not readily adapted to modern semiconductor technology. Another segmented converter is described in U.S. Pat. No. 3,997,892, issued December 1976, inventor Susset. The segmented converter described in U.S. Pat. No. 4,543,560 includes a resistor string for both the first and second stages with buffer amplifiers between the stages to prevent the second stage resistor string from loading the first resistor string.
Another type of segmented DAC is described in U.S. Pat. No. 5,495,245, issued Feb. 27, 1996, inventor James J. Ashe, assigned to the same assignee as the present invention. The DAC described therein includes a pair of first stage resistor strings coupled to a second resistor string through a first switching network. A pair of reference voltages are coupled to the pair of resistor strings. The first switching network operates such that a voltage produced at a selected one of the resistors in one of the pair of first stage resistor strings and a voltage produced at a selected one of the resistors in the other one of the pair of first resistor strings are coupled across the second stage resistor string. A second switching network couples an output at a selected one of the resistors in the second resistor string to an output of the DAC. Buffer amplifiers are not included between the pair of first stage resistor strings and the second stage resistor string. Two arrangements are described. In one arrangement, the first switching network responds to the Most Significant Bits (MSBs) and the second switching network responds to the Least Significant Bits (LSBs). In the other arrangement, the first switching network responds to the LSBs and the second switching network responds to the MSBs. In former arrangement, each resistor in the pair of resistor strings has a value 2N*R, where R is the resistance of each of the 2N/2 resistors in the second resistor string. In the latter arrangement, each resistor in the second resistor string has a value 2N/2*R, where R is the resistance of each resistor in the pair of first resistor strings. In both arrangements, the entire current passing between the pair of reference voltages passes through the resistors. Therefore, while such arrangements are useful in many applications the relatively high number of resistors which are required in both the first and second pairs of resistor strings thereby requiring relative large chip surface area for their fabrication.
Another problem with these type of DACs is that low 'on' impedance requires large switches that have large unwanted parasitic capacitance due to the relatively large area of the switches. This capacitance results in slowing down the switching transient operation of the converter and limits higher speed performance. Minimum sized switches are therefore desirable to minimise the capacitance. A further problem with large, low 'on' impedance switches is that they have proportionally higher device leakage currents. Diode leakage and MOS 'off leakage' are an unwanted error component in string DAC's. The leakage components are also highly temperature dependent and these leakage currents can limit the maximum operating range of an Integrated Circuit (IC). Minimum sized switches are therefore desirable to minimise device leakage effects.
A further type of DAC is described in U.S. Pat. No. 5,969,657 issued Feb. 19, 1999, inventor Dennis Dempsey et al, assigned to the same assignee as the present invention and incorporated herein by reference. Referring to prior art FIGS. 1 and 2, a DAC 10 is shown to adapted to convert an N bit, here N=4, digital word, I4 I3 I2 I1, (where bit I1 is the least significant bit (LSB) and I4 is the most significant bit (MSB)) into a corresponding analog signal, Vo, at output terminal 11. The DAC 10 includes a pair of resistor strings 12, 14. Resistor string 12 is adapted for coupling across a voltage supply 15. The voltage supply 15 produces a voltage, +V, at terminal 16 relative to ground potential at terminal 18. The first resistor string has a plurality of, here 2N/2, (i.e., 4) resistors Ra1–Ra4, serially connected between terminals 16 and 18, as shown. The resistance of each one of the resistors Ra1–Ra4 is here R1 ohms. It is noted that resistors Ra1, Ra2, Ra3 and Ra4 have: resistor Ra1 terminals T0, T1; resistor Ra2 terminal T1, T2; resistor Ra3 terminals T2 and T3; and, resistor Ra4 terminals T3 and T4, respectively, as shown. Resistor Ra4 terminal T4 is connected to terminal 16 and resistor Ra1 terminal T0 is connected to input terminal 18, as shown. The resistors Ra1–Ra4 in the resistor string 12 produce voltages at the terminals T1–T3 in response to current fed thereto from the voltage supply 15.
The second resistor string 14 has a plurality of, only 2N/2−1, here three resistors Rb1, Rb2, and Rb3 of substantially equal resistance, have a resistance of R2 ohms, serially coupled between a pair of second resistor string 14 input terminals 26, 28, as shown. It is noted that 2N/2−1 is an odd integer. Resistors Rb1, Rb2 and Rb3 have: resistor Rb1 terminals Q1, Q2, resistor Rb2 has resistor terminals Q2, Q3, and resistor Rb3 has resistor terminals Q3, Q4, respectively, as shown. Terminal Q1 is connected to input terminal 28 and terminal Q4 is connected to input terminal 26.
The DAC disclosed by U.S. Pat. No. 5,969,657 integrates the MSB switch impedance into the transfer function such that the MSB switch impedance causes a step in the transfer function of one LSB when the LSB DAC switches between neighbouring MSB resistors. The impedance of the MSB switches is proportional to the DAC resistors, thereby requiring a larger area for each switch for applications which require reasonably low impedance switches. A requirement for low impedance switches can increase the IC surface area and cost of a circuit, which is undesirable and restricts the design of the DAC. Additionally a problem with large low impedance switches is that due to the larger surface area the self capacitance of the switch increases which slows down the speed of the DAC and diode leakage which sets a lower power operation limit. Switch capacitance is also a particular problem for high speed DAC's which are implemented using MOS design or other similar switch design techniques.
There is therefore a need to provide a Digital to Analog Converter which saves on chip surface area, reduces the number of resistors and implementation cost, reduces the self capacitance and the device leakage currents of the circuit elements. A further need is to increase the DAC transition speed and improve the overall performance of the converter. Another need in the field of Digital to Analog Converters is to increase the accuracy of a dual string digital to analog converter by reducing the number of device leakage components. A further need is to increase the operation temperature range for the switching devices in a switched dual string digital to analog converter.


Vanadyl pyrophosphate oxidation catalyst precursors comprise vanadium phosphate esters of the formula EQU (VO)(((R.sub.1-x /H.sub.x)OPO.sub.3).multidot.((ROH).sub.y /(H.sub.2 O).sub.z). wherein, R is an alkyl group capable of bonding, through oxygen, to phosphorus to form a phosphate ester; x is 0 to about 0.5; y is 0-1.0; z is 0-1.25; and y+z is 0-1.25 are particularly useful for the selective oxidation of butane to maleic anhydride and readily thermally decompose to form the vanadyl pyrophosphate oxidation catalysts.

This invention relates to vanadyl pyrophosphate oxidation catalyst precursors comprising vanadium phosphate esters and to a process of converting the precursors to vanadyl pyrophosphate oxidation catalysts by thermal decomposition.
Maleic anhydride is used as a raw material for numerous products, including agricultural chemicals, paints, paper sizing, food additives and synthetic resins. To fill the high demand for this valuable chemical, a variety of commercial processes have been developed for its production, the most successful of which involves the vapor phase oxidation of n-butane to maleic anhydride in the presence of a vanadyl pyrophosphate ("VPO") catalyst. Since the development of this method in the 1970's, research has continued to improve the reaction conditions and, particularly, the VPO catalysts.
A review of the improvements made in this technology is given by G. J. Hutchings, in Applied Catalysis, Elsevier Science Publishers B. V. Amsterdam, 72(1991), pages 1-31. The preferred method of preparation of VPO catalysts is the hydrochloric acid digestion of V.sub.2 O.sub.5 and H.sub.3 PO.sub.4 in either an aqueous solvent, as described, for example, in U.S. Pat. No. 3,985,775, or non aqueous solvent, such as methanol, tetrahydrofuran (THF) or isobutanol, followed by solvent removal to give what is termed the catalyst precursor, vanadium hydrogen phosphate, VO(HOPO.sub.3).multidot.(H.sub.2 O)0.5. The precursor is then activated by heating, as described, for example, in U.S. Pat. No. 3,864,280 and U.S. Pat. No. 4,043,943. Other methods are described in U.S. Pat. No. 4,132,670 and U.S. Pat. No. 4,442,226.
Johnson et al. (Inorg Chem. 23, 3842 (1984); J Am. Chem. Soc. 111, 381 (1989)) have described a series of compounds given by the formula VO(RPO.sub.3).multidot.H.sub.2 O R'OH, where R' represent alkyl groups from alcohol molecules and R represent alkyl groups attached to phosphorus atoms. These compounds are described as vanadyl alkylphosphonates since the alkyl groups, R, are bound directly to the trivalent phosphorus. Alkyl groups expressed as C.sub.n H.sub.2n +1 for n=2-9, 14 and 18 are disclosed. While these compounds are layered, only those with n<3 and just H.sub.2 O in the interlayer space have structures which are analogous to VO(HOPO.sub.3).multidot.(H.sub.2 O)0.5. Thermogravimetric results of Huan et al. (Materials Chemistry and Physics 35, 199 (1993)) and Guliants et al. (Chem. Mater. 7, 8! 1493 (1995)) showed that complete thermal decomposition of these phases in air requires temperatures >500.degree. C. and -375-475.degree. C., respectively. Johnson et al. did not comment on the decomposition products. Guliants et al. did disclose that these compounds could be converted to VPO at temperatures lower than the vanadium hydrogen phosphate, VO((HOPO.sub.3).multidot.(H.sub.2 O)0.5.
U.S. Pat. No. 5,401,707 describes a series of compounds with the general formula, VO(HOPO.sub.3).multidot.(H.sub.2 O)0.5 ({C.sub.n H.sub.2n +}-X).sub.z in which n has a value of from 0 to 20, z has a value of from about 1.5 to about 1.9; and X is an oxygen or nitrogen containing functional group. These phases consist of the known VOHOP.sub.3 .multidot.(H.sub.2 O)0.5 intercalated with a compound such as an alkyl amine. The conversion of these precursors to (VO).sub.2 P.sub.2 O.sub.7 at temperature of at least 400.degree. C. is disclosed.
Alagna et al. (Mat. Res. Bull. 22, 691 (1987)) have described the synthesis of VOHOPO.sub.3 .multidot.(H.sub.2 O).sub.1.25 .multidot.(EtOH)0.5. This material is reported to have a basal plane spacing of 1.358 nm and a structure consisting of vanadyl hydrogen phosphate, VO(OHPO.sub.3).multidot.(H.sub.2 O)0.5 whose layers are intercalated with ethanol molecules. The compound decomposes, non-topotactically, to an amorphous substance at .about.400.degree. C.


A compact jaw muscle exercise device that people use to strengthen and tone jaw muscles which includes a generally wedged shape body of plastic having upper and lower surfaces adapted to engage one's teeth. Holes run transversely through the body, which increases the deformability of the exercise device. The exercise device's resistance may be increased by inserting cylindrical members through the holes.

Field of the Invention
The present invention relates generally to the human muscle exercise apparatus and, more specifically, to an exercise device for muscles in the jaw area to strengthen and tone these muscles.
Because of the location of the jaw muscles, it is difficult to target these muscles with exercisers. Since the exerciser will be in use in or around one's mouth, it is important that the device not obstruct the user's air flow. Therefore, it is desirable to provide a compact device for exercising one's jaw muscles which allows the user to target the muscles.


Fluorine-free photoacid generators and photoresist compositions containing fluorine-free photoacid generators are enabled as alternatives to PFOS/PFAS photoacid generator-containing photoresists. The photoacid generators are characterized by the presence of a fluorine-free heteroaromatic sulfonate anionic component. The photoacid generators preferably contain an onium cationic component, more preferably a sulfonium cationic component. The photoresist compositions preferably contain an acid sensitive imaging polymer. The compositions are especially useful for forming material patterns using 193 nm (ArF) imaging radiation.

In the field of semiconductor manufacturing, optical lithography has been the mainstream approach used in patterning semiconductor devices. In typical prior art lithography processes, UV light is projected onto a silicon wafer coated with a thin layer of photosensitive resist (photoresist) through a mask that defines a particular circuitry pattern. Exposure to UV light, followed by subsequent baking, induces a photochemical reaction which changes the solubility of the exposed regions of the photoresist. Thereafter, an appropriate developer, usually an aqueous base solution, is used to selectively remove photoresist either in the exposed regions (positive-tone photoresists) or, in the unexposed regions (negative-tone photoresists). The pattern thus defined is then imprinted on the silicon wafer by etching away the regions that are not protected by the photoresist with a dry or wet etch process.
One type of photoresist employed in the prior art is a chemically amplified photoresist which uses acid catalysis. A typical prior art chemically amplified photoresist, for example, is formulated by dissolving an acid sensitive polymer and a photoacid generator in a casting solution. A chemically amplified photoresist is especially useful when relatively short wavelength radiation is employed, including deep UV radiation 150-315 nm wavelengths, and mid-UV radiation, e.g., 350-450 nm wavelengths. The shorter wavelengths are typically desired to increase resolution, and thus, decrease feature size of the semiconductor devices, but fewer photons are radiated for a given energy dose.
Accordingly, higher exposure doses are typically required when using UV radiation to obtain a sufficient photochemical response in the photoresist unless a chemically amplified photoresist is employed. In a chemically amplified photoresist, acid sensitivity of the base polymer exists because acid sensitive side chain groups are bonded to the polymer backbone. When such a photoresist is exposed to radiation, the photoacid generator produces an acid that, when the photoresist is heated, causes catalytic cleavage of the acid sensitive side chain groups. A single acid catalyst molecule generated in this manner may be capable of cleaving multiple side chain groups, thus allowing lower exposure doses for the needed photochemical response.
Because of the relatively low intensity of ArF laser source and relatively high binding energy of acid labile moieties in ArF photoresist, photoacid generators which can produce stronger Bronsted acid with much higher sensitivity are preferred to realize such chemical amplification in commercial lithography. Fluorine-containing onium salts, such as perfluoronated octyl sulfonate (PFOS) and perfluoronated alkyl sulfonate (PFAS), are generally preferred used as the photoacid generator in ArF photoresist system in part because they result in generation of strong acid.
In recent years, there has been a desire in the microelectronics industry to eliminate the use of perfluorinated carbons (PFCs) such as PFOS and PFAS. Thus, there is a desire to find alternative photoacid generators which can be used without adversely impacting the performance of lithographic processes. There has also been a desire to minimize or eliminate fluorine content in photoresist in order to improve etch resistance and to improve process latitude in high numeric aperture (NA>0.95) imaging processes.
Some attempts have been made to develop photoresist formulations that do not use perfluorinated carbon-containing photoacid generators, however these have largely been unsuccessful in achieving performance comparable to formulations using PFOS. Thus, there is a need for new and improved photoacid generators and chemically amplified photoresist compositions that enable the substantial reduction or avoidance of PFCs and/or fluorine in photoresist compositions.

Fluorine-free heteroaromatic photoacid generators and photoresist compositions containing the same

International Business Machines Corporation


This invention relates to light guide devices and methods of manufacture. The light guide device is suitable for use in a range of applications, particularly in connection with the backlighting of displays, for example, liquid crystal displays.

A number of light guiding devices are known. These devices are employed for a range of functions including illumination, backlighting, signage and display purposes. Typically, the devices are constructed from an injection moulded or machined transparent plastic component, where a light source, such as a fluorescent lamp or a plurality of light emitting diodes (LEDs), is integrated by means of mechanical attachment at the edge of the transparent plastic component.
Common to all of these devices is the fact that light from the light source is guided through a transparent guide, typically made of plastic, by total internal reflection. For backlighting applications, light is emitted in a substantially perpendicular direction to that of the direction of propagation of the light within the transparent guide. This is achieved through the light being directed so as to interact with scattering structures or films located within, or on the surface of, the transparent guide.
The integration of fluorescent lamps or LEDs to the edge of the transparent light guide is not a straightforward process and thus significantly increases the complexity of the production process for these devices. Achieving a good coupling of the light source and the light guide is essential to the optical performance of the device. In addition, edge coupling of the light sources renders these components susceptible to mechanical damage during both the production process and the normal use of the device.
In seeking to provide thin direct lit backlights, it is preferable to have light emitted into the plane of the light guide. Further benefit may be obtained if the light sources are distributed across the panel, so minimising the length of guiding in the light guide. This has the benefit of creating a thin and efficient backlight but has the disadvantage of compromising the light uniformity. For example, this may be through the creation of dark spots and/or more intense areas of light above or in the vicinity of the light source. Preferably, these dark spots and/or more intense areas of light should not be visible or, at least, reduced in appearance in order to provide at least acceptable, and more preferably, improved light uniformity. Existing solutions to this problem tend to add considerable thickness to the backlight.
Many backlights fall into the categories of "edge-lit" or "direct-lit". These categories differ in the placement of the light sources relative to the output of the backlight, where the output area defines the viewable area of the display device. In edge-lit backlights, one or more light sources are disposed along an outer border or edge of the backlight construction outside the zone corresponding to the output area. The light sources typically emit light into a light guide, which has length and width dimensions of the order of the output area and from which light is extracted to illuminate the output area. In direct-lit backlights, an array of light sources is disposed directly behind the output area, and a diffuser is placed in front of the light sources to provide a more uniform light output. Some direct-lit backlights also incorporate an edge-mounted light, and are thus illuminated with a combination of direct-lit and edge-lit illumination.
Apart from producing light, the light sources also produces heat. If the heat dissipates into a liquid crystal panel for example, the display quality may be adversely affected. Because the transfer of heat to the liquid crystal panel is unlikely to be uniform, the liquid crystal layer within the liquid crystal panel may be subjected to different degrees of heating. This non-uniform distribution of heat may also affect the switching of thin film transistors inside the liquid crystal display and the overall display quality of the liquid crystal panel may deteriorate. There are numerous challenges to overcome in thermally managing a backlight unit for use in combination with displays. Addressing issues surrounding thermal management should not result in an unacceptable increase in weight or thickness or compromise the mechanical integrity of the backlight unit. In addition, the optical performance of the backlight unit should not be significantly compromised.
Other challenges facing display manufacturers, such as those incorporating large area LED Back Light Units (BLUs) include producing a thin and efficient device which enables 2-d or 3-d spatial dimming to support high display performance and reduced power consumption. This has proved problematic for both edge-lit and direct lit devices and has typically resulted in thicker backlight devices. 2-d dimming relates to when the image content of the display is achieved by only switching on selected areas of the backlight which match or correspond to the desired image thus resulting in significant power reduction. 3-d dimming further incorporates the use of colour.
The beam angle of light emerging from a backlight and the uniformity of said beam angle are important in determining the efficiency and the viewing angle of the display that is being illuminated. Some degree of control over the range of light output angles provided by the backlight is desirable.
It is an object of the present invention to provide a light guiding device that addresses one or more of the aforesaid issues.


A fully differential CMOS peak detection circuit has a differential input stage and a negative feedback loop that form a differential unity gain feedback amplifier. The differential output of the differential input stage is applied to a differential peak detect circuit having a pair of series diode/capacitor combinations. The diode/capacitor junctions are applied to differential inputs of the negative feedback loop. A common mode correction circuit is coupled to the differential CMOS peak detection circuit to minimize differences between the common mode voltages of the differential input stage and the negative feedback loop. The differential peak voltage is held at the differential output of the differential input stage for sampling by a sampling circuit during a readback interval, and then tracks a differential input signal applied to the differential input of the differential input stage during a tracking interval. The differential peak detection circuit then peak detects during a peak detect interval that is equal to a desired sample time window.

The present invention relates to peak detection circuits, and more particularly to a wholly differential CMOS peak detection circuit that provides improved linearity, better noise immunity and less sensitivity to process variations.
Glitches and noise spikes are a common cause of problems in both analog and digital circuits. Modern oscilloscopes, such as digital storage oscilloscopes (DSO), need to be able to capture these narrow pulses to be useful in troubleshooting such circuits. Also such pulses may be as narrow as two nanoseconds (2 ns), which can trigger TTL circuitry, so the DSO needs to be able to obtain at least one sample of such a spike. When the time base of the DSO is adjusted so that the input signal is highly undersampled, the period between samples may be greater than the width of such spikes. Therefore the spikes may rarely or never be sampled. As a result peak detectors have been placed in the signal acquisition circuitry between the input and a digital sampler. In this way the minimum and maximum of the input signal within a specified time window is detected and held until they can be sampled or converted by an analog-to-digital converter (ADC).
An example of a prior art peak detector using bi-polar technology is present in the Tektronix 2430 DSO, manufactured by Tektronix, Inc. of Beaverton, Oreg., United States of America. The input signal is split into two opposite polarity signals that are fed into two positive and two negative peak detectors to allow detection of either positive or negative spikes. By using two peak detectors for each polarity, one can be peak detecting while the other is either holding for sampling or tracking. The peak detectors in this configuration peak detect for two intervals, hold for one interval and track for another interval before repeating the cycle, where two intervals are equal to a sample period. Each peak detector has an output stage for amplification prior to the sampling circuitry.
A peak detect cell for the Tektronix 2430 DSO is shown in FIG. 1 in the form of a simple unity gain feedback amplifier with a wide bandwidth. Transistors Q1-Q4 form a differential amplifier with a current source load I1. The output of the differential amplifier is fed back to the input through diode D and transistors Q5, Q6. When control signals S1, S2 are both low, the peak detector is in the detect mode. If the input signal Vin is greater than the output signal Vout, then capacitor C charges until Vin equals Vout. However if Vin is less than Vout, then diode D prevents the capacitor C from discharging so that Vout maintains the most positive value of Vin.
At the end of the detection period, the output signal is held and further inputs are ignored so that Vout may be sampled. At this point control signal S2 is high while S1 is still low to disconnect the input from the output. After Vout is sampled, control signal S2 is lowered and S1 is raised so that the diode D is bypassed while the input signal is enabled, and the capacitor is allowed to charge or discharge to track the input signal Vin. However bi-polar technology is relatively expensive and uses relatively high power, there is base current leakage from the storage capacitor C, there is a large offset due to the Darlington differential pair, there is no clamp of transistor Q3 (with the potential of saturation), there is excess delay around the closed loop (with the potential of ringing), and the circuit is single ended.
A CMOS based peak detector is disclosed in U.S. patent application Ser. No. 07/844,089, filed on Mar. 2, 1992 by Grigory Kogan and entitled "CMOS-BASED PEAK DETECTOR FOR FAST-IN, SLOW-OUT MIN/MAX DETECTION." CMOS technology is less expensive, more dense and uses less power than comparable bipolar technology, but is slower and must be configured differently to achieve high bandwidth operation. Referring to FIG. 2 two nodes A, B of a CMOS peak detector cell are coupled to a voltage rail Vdd during a precharge interval, after which they are disconnected. An acquire signal controls a switch Q1 that connects one node A to an input signal Vin, the one node being connected to the other node B by a transistor Q4 so that the capacitance C at the other node tracks the voltage at the first node. At the end of the acquisition interval the first node A is disconnected from the input signal Vin and the voltage on the other node B is held for transfer via a buffer amplifier AO to a sampler. Following transfer a clear signal connects the other node B to the voltage rail Vdd in preparation to repeat the cycle. However this circuit is relatively slow, the source follower Q4 has no current source so that point B dribbles down to one V.sub.T above point A producing a long tail, and the circuit is single ended.
What is desired is a CMOS peak detector circuit that is fully differential to provide the advantages of both differential circuitry and CMOS technology in a peak detector.

Differential CMOS peak detection circuit


A phosphorus-free based halogen-free flame-retardant resin composition includes a base polymer including a copolymer of ethylene and α-olefin having carbon number of 3 to 8 polymerized by a metallocene catalyst as a main component, and 5 to 30 weight % of an ethylene-vinyl acetate copolymer that has a melt flow rate of not less than 50 g/min and a vinyl acetate content of not less than 40%, a metal hydroxide blended with the base polymer in a ratio of 100 to 250 parts by weight relative to 100 parts by weight of the base polymer, and a mineral oil blended with the base polymer in a ratio of 1 to 20 parts by weight relative to 100 parts by weight of the base polymer.

1. Field of the Invention
This invention relates to a phosphorus-free based halogen-free flame-retardant resin composition that has high flame-retardant properties that pass foreign flame-retardant standards (EN, DIN, BS), is excellent in mechanical characteristics, and has a flat and smooth extrusion appearance, a phosphorus-free based halogen-free flame-retardant insulated electric wire and a phosphorus-free based halogen-free flame-retardant cable.
2. Description of the Related Art
In recent years, wires and cables with insulations that do not use polyvinyl chloride and halogen based flame-retardants so as to be reduced in environmental load spread rapidly as so-called "eco-electric wire" and "eco-cable".
In the halogen-free flame-retardant electric wire and the halogen-free flame-retardant cable, it is common to use a resin composition as an insulator of the electric wire, the resin composition configured such that halogen-free flame-retardants such as magnesium hydroxide are blended in a polyolefin in large amounts.
In order to realize high flame-retardant properties in a vertical flame test that pass the foreign flame-retardant standards (EN, DIN, BS) by using the halogen-free flame-retardants such as magnesium hydroxide, it is necessary for the halogen-free flame-retardants to be blended therein in large amounts, thus there is a problem that mechanical characteristics such as tensile strength, elongation are drastically lowered.
For the purpose of solving the above-mentioned problem, a method of using a polyolefin as a base polymer has been proposed, the polyolefin being polymerized by a metallocene catalyst, and having narrow molecular weight distribution, high strength and flexibility (for example, refer to JP-A-2009-019190).

Phosphorus-free based halogen-free flame-retardant resin composition, phosphorus-free based halogen-free flame-retardant insulated electric wire and phosphorus-free based halogen-free flame-retardant cable


The present application relates to a method and apparatus for MPDCCH performance enhancement. One embodiment of the present disclosure provides an apparatus comprising: a receiver that receives a first reference signal, a second reference signal and a control signal; and a processer that decodes the control signal based on at least one of: the first reference signal and the second reference signal, wherein the second reference signal on an antenna port is associated with a precoder, and the antenna port of the second reference signal and the precoder for the antenna port of the second reference signal are adopted within a time duration and a frequency band.

In Rel.13, the Demodulation Reference Signal (DMRS) is used for decoding MTC Physical Downlink Control Channel (MPDCCH), while the Cell-Specific Reference Signal (CRS) is not.
For Rel.13, the demodulation of MPDCCH is based on DMRS as Enhanced Physical Downlink Control Channel (EPDCCH). In order to enhance the performance of MPDCCH, combining DMRS with CRS is proposed to be considered in Rel.16
In order to improve the performance of MPDCCH, an approach for combining DMRS with CRS for MPDCCH demodulation is desired.

Method and apparatus for MPDCCH performance enhancement


Formation of dioxins in flue gases is inhibited by contacting the flue gas with at least one of sodium phosphite, calcium phosphate, sodium hypophosphite, and calcium as reducing agents preferably at a temperature in the range of from 150xc2x0 C. to 850xc2x0 C. Hydrogen chlorides are also rendered harmless by the contact with the reducing agent. Also, metal ions contained in the fly ash of the flue gas are reduced to metals to reduce the occurrence of dissolution of the metals in subsequent treatment of the fly ash.

1. Field of the Invention
The present invention relates to a method for removing and/or reducing formation of harmful substances in flue gas.
2. Description of the Background Art
Various harmful substances are contained in flue gas exhausted from a refuse incineration site or the like, and various treating methods are adopted for removing the harmful substances contained in such flue gas. However, in recent years, extremely toxic chlorides such as dioxins (PCDDS, PCDFS, etc.) may have been contained at a high concentration in flue gas exhausted from a refuse incinerator or the like in some cases, which has become a major social problem.
The incineration treatment of waste in a refuse incineration site is generally conducted through (1) a step of incinerating the waste, (2) a secondary combustion step of heating flue gas generated in the incineration step to a higher temperature to additionally burn unburned substances (for example, carbon monoxide, low molecular weight hydrocarbons, etc.) remaining in the flue gas, (3) a heat recovery step and/or a cooling step to recover heat from the flue gas heated to the higher temperature and/or lowering the temperature of the flue gas, (4) a dust collection step of removing fly ash in the flue gas, (5) a step of making the flue gas harmless by removing harmful substances in the flue gas, and (6) a step of exhausting the flue gas treated in step (5) through a stack. Among these respective steps, dioxins contained in the flue gas are said to be mainly formed in step (3), the heat recovery and/or the cooling step, in which the temperature of the flue gas is lowered, and after that step.
In order to reduce the concentration of chlorides in the flue gas, it is said that spraying of an aqueous solution of calcium hydroxide on the flue gas, which is generally conducted for removing hydrogen chloride in the flue gas, is also effective to some extent. However, this method is not always said to be satisfactory. Therefore, in order to more effectively reduce the chlorides in the flue gas, there is adopted, for example, a method in which flue gas is brought into contact with an adsorbent such as active carbon or active coke to adsorb and remove chlorides in the flue gas. Since this method is simple and effective as a method for removing the chlorides, it is adopted in many refuse incineration site and the like. However, this method requires treating waste active carbon on which the chlorides have been adsorbed and has thus been accompanied by a problem of additional operation cost due to the step of subjecting the waste active carbon to a burning treatment at a high temperature and plant cost due to the burning treatment.
The present invention has been completed in view of the foregoing circumstances, and has as its object the provision of a method of making flue gas harmless, by which the formation of dioxins and the like in the flue gas can be reduced with good efficiency, and metals contained in fly ash collected in a dust collection step can be prevented from being easily dissolved out.
According to the present invention, there is thus provided a method of making flue gas generated upon incineration of waste harmless, which comprises bringing the flue gas into contact with a reducing agent.
In the method of the present invention, it is preferred that the flue gas is brought into contact with the reducing agent in a step in which the temperature of the flue gas is lowered to 1,000xc2x0 C. or lower. It is more preferred that the flue gas is brought into contact with the reducing agent in a step in which the temperature of the flue gas is lowered to from 850xc2x0 C. down to 150xc2x0 C. It is further preferred that the flue gas be brought into contact with the reducing agent in a heat recovery step of recovering heat of the flue gas and/or a cooling step of lowering the temperature of the flue gas. It is also preferred that the flue gas be brought into contact with the reducing agent after a heat recovery step of recovering heat of the flue gas and/or a cooling step of lowering the temperature of the flue gas, but before a dust collection step. The reducing agent used in the method of the present invention is preferably at least one selected from the group consisting of phosphorous acid and derivatives thereof, hypophosphorous acid and derivatives thereof, metal hydrides, metal hydrogen complex compounds, sulfurous acid and derivatives thereof, boranes, hydrazines, phosphines, hydrogen, and alkali metals. The reducing agent is more preferably at least one selected from the group consisting of phosphorous acid and derivatives thereof, and hypophosphorous acid and derivatives thereof. In the method of the present invention, it is preferred that fly ash in the flue gas be collected in a dust collecting equipment after bringing the flue gas into contact with the reducing agent. As a result, ionic metals contained in the fly ash may be reduced by the reducing agent to keep them in a state in which the metals are hard to dissolve out of the fly ash.
In the present invention, at least one reducing agent selected from the group consisting of phosphorous acid and derivatives thereof, hypophosphorous acid and derivatives thereof, metal hydrides, metal hydrogen complex compounds, sulfurous acid and derivatives thereof, boranes, hydrazines, phosphines, hydrogen, and alkali metals is used as a reducing agent. Examples of the phosphorous acid and derivatives thereof include phosphorous acid, potassium phosphite, sodium phosphite, sodium hydrogen- phosphite, calcium phosphite, magnesium phosphite and ammonium hydrogenphosphite. Examples of the hypophosphorous acid and derivatives thereof include hypophosphorous acid, potassium hypophosphite, sodium hypophosphite and calcium hypophosphite.
Examples of the sulfurous acid and derivatives thereof include sulfurous acid, and sulfites such as ammonium sulfite, sodium sulfite, ammonium hydrogensulfite and sodium hydrogensulfite. Examples of the boranes include boron hydrides (diborane, tetraborane, dihydropentaborane, etc.), monalkyldiboranes (methyldiborane, etc.), dialkyldiboranes (dimethyldiborane, etc.), trialkyldiboranes (trimethyldiborane, etc.), tetraalkyldiboranes (tetramethyldiborane, etc.), and metal salts of boranes (lithium borohydride, sodium borohydride, etc.). Examples of the hydrazines include hydrazine, hydrazine dihydrochloride, hydrazine hydrates, hydrazine hydrochloride and hydrazine sulfate. Examples of the phosphines include primary phosphines such as phosphine, methylphosphine, ethylphosphine, propyl-phosphine, isopropylphosphine, isobutylphosphine, phenyl-phosphine and monoethanolphosphine, secondary phosphines such as dimethylphosphine, diethylphosphine, diisopropyl-phosphine, diisoamylphosphine, diphenylphosphine and diethanolphosphine, and tertiary phosphines such as trimethylphosphine, triethylphosphine, triphenylphosphine, methyldiphenylphosphine, dimethylphenylphosphine and triethanolphosphine. Examples of the alkali metals include metals such as lithium, sodium and potassium. A solution composed mainly of a waste solution from electroless nickel plating containing any of the above phosphorous acid and derivatives thereof and/or any of the above hypophosphorous acid and derivatives thereof may also be used as the reducing agent. The waste solution from electroless nickel plating basically contains, in addition to the phosphorous acid or the derivative thereof and/or the hypophosphorous acid or the derivatives thereof, ions such as a nickel ion, sulfate ion, complexing agent ion and sodium ion, a brightener, a surfactant, a stabilizer, and a trace amount of metal ion(s) dissolved out of a substance to be plated. The concentrations of these components are not always constant. However, the waste solution contains, for example, about 10 to 55 g/liter of phosphite ions, about 80 to 160 g/liter of hypophosphite ions, about 4 to 7 g/liter of nickel ions, about 30 to 75 g/liter of sulfate ions, about 30 to 55 g/liter of complexing agent ions and about 46 to 120 10 g/liter of sodium ions and has a pH of about 3.5 to 5.5. Incidentally, the waste solution from electroless nickel plating may be subjected to a denickelization treatment so as to substantially contain no nickel ion. An alkali compound and an amide compound may be additionally contained in the waste solution from electroless nickel plating. Examples of the alkali compound include potassium hydroxide, sodium hydroxide, potassium carbonate, potassium hydrogencarbonate, sodium carbonate and sodium hydrogencarbonate. Examples of the amide compound include potassium amide and sodium amide.
At least two of the above-mentioned reducing agents, which are of the same kind but different from each other, or are of different kinds, may be optionally used in combination as the reducing agent. The flue gas generally contains hydrogen chloride. In order to remove this hydrogen chloride, a slurry or powder of calcium hydroxide is usually sprayed on the flue gas. The contact of the reducing agent with the flue gas can inhibit the formation of dioxins, and moreover also has an effect of removing hydrogen chloride contained in the flue gas at the same time.
Even if the precursors of dioxins are contained in flue gas, there is no possibility that dioxins will be formed from the precursors while the temperature of the flue gas is kept high. However, when the temperature of the flue gas is lowered, dioxins tend to be formed from the precursors. Therefore, it is preferred that the flue gas be brought into contact with the reducing agent at a temperature at which the dioxins are easily formed from the precursors, namely, in a step in which the temperature of the flue gas is lowered to 1,000xc2x0 C. or lower in a waste incineration process, preferably, in a step in which the temperature is lowered from 850xc2x0 C. down to 150xc2x0 C. For example, it is preferred to bring the flue gas into contact with the reducing agent in a heat recovery step of recovering heat of the flue gas and/or a cooling step of lowering the temperature of the flue gas by blowing cooling water against the flue gas, or after these steps (but before a dust collection step). Methods for bringing the flue gas into contact with the reducing agent include a method of spraying an aqueous solution or slurry of the reducing agent on the flue gas and a method of spraying powder of the reducing agent on the flue gas. The amount of the reducing agent used varies according to the kind of the reducing agent used. In the case of the phosphorous acid or derivative thereof, or the hypophosphorous acid or derivative thereof, it is preferably 0.01 to 10 g per m3 of the flue gas. In the case of the metal hydride, metal hydrogen complex, borane or hydrazine, it is preferably 0.001 to 7 g per m3 of the flue gas. In the case of the sulfurous acid or derivative thereof, it is preferably 0.1 to 10 g per m3 of the flue gas. In the case of the phosphine or hydrogen, it is 10 preferably 0.01 to 10 liters per m3 of the flue gas. In the case of the alkali metal, it is preferably 0.1 to 5 g per m3 of the flue gas. In the case where at least two reducing agents different in kind from each other are used in combination, it is preferred that their amounts added be suitably controlled within the above preferred ranges of amount of the respective reducing agents to be used according to the mixing proportions of the reducing agents, and the like.
In the method of present invention, it is preferred to collect fly ash in the flue gas in a dust collector after bringing the flue gas into contact with the reducing agent. As the dust collector, there may be used any known dust collector such as an electrical dust precipitator, filter dust separator, centrifugal dust separator, gravitational dust collector or inertial dust collector. According to the method of the present invention, since the flue gas is brought into contact with the reducing agent, metals (ionic metals) in the fly ash contained in the flue gas are reduced to a metallic state by the reducing agent, so that the metals contained in the fly ash become hard to be dissolved out of the fly ash. Accordingly, when the fly ash in the flue gas is collected and removed after bringing the flue gas into contact with the reducing agent, secondary contamination due to the dissolving-out of the metals contained in the fly ash can be made hard to occur. However, a treatment with a metal scavenger for scavenging and fixing metals contained in the flue gas and/or the fly ash may be used in combination as needed. A treatment with calcium hydroxide for removing hydrogen chloride contained in the flue gas may also be used in combination. The metal scavenger and calcium hydroxide may be brought into contact with the flue gas either separately from or at the same time as the reducing agent. The fly ash separated and removed from the flue gas may be treated by solidifying it with cement or the like.


A method for controlling movement of an elevator car during an emergency stop includes the steps of determining the load of the car; determining the travel direction of the car; and monitoring the speed of the car. When the car is determined to be either lightly loaded and travelling downwards, or heavily loaded and travelling upwards, brake torque is applied only when the speed of the car reaches zero, as slowing of the car can be accomplished solely by virtue of the balancing factor of the car's counterweight.

In an elevator installation, an elevator car and a counterweight are conventionally supported on and interconnected by traction means. The traction means is driven through engagement with a motor-driven traction sheave to move the car and counterweight in opposing directions along the elevator hoistway. The drive unit, consisting of the motor, an associated brake and the traction sheave, is normally located in the upper end of the elevator hoistway or alternatively in a machine room directly above the hoistway.
Safety of the elevator is monitored and governed by means of a safety circuit or chain containing numerous contacts or sensors. Such a system is disclosed in U.S. Pat. No. 7,353,916. Should one of the safety contacts open or one of the safety sensors indicate an unsafe condition during normal operation of the elevator, the controller instructs the drive to perform an emergency stop by immediately de-energizing the motor and applying the brake. The elevator cannot be called back into normal operation until the reason for the break in the safety circuit has been investigated and the relevant safety contact/sensor reset.
Traditionally, steel cables have been used as traction means. More recently, synthetic cables and belt-like traction means comprising steel or aramid cords of relatively small diameter coated in a synthetic material have been developed. An important aspect of these synthetic traction means is the significant increase in the coefficient of friction they exhibit through engagement with the traction sheave as compared to the traditional steel cables. Due to this increase in relative coefficient of friction, when the brake is applied in an emergency stop for an elevator employing synthetic traction means there is an significant increase in the deceleration of the car which severely degrades passenger comfort and could even result in injury to passengers.
GB-A-2153465, U.S. Pat. No. 5,323,878 and U.S. Pat. No. 5,244,060 all describe methods of controlling the movement of an elevator car during an emergency stop wherein the brake is automatically and immediately applied but the degree of the brake force or torque exerted by the brake is dependent on the load of the car. These methods help reduce deceleration of the elevator car during an emergency stop.

Selective elevator braking during emergency stop


The invention includes a device, method, and system for clothing organization that includes a hanging structure, such as a large hook, attached to a hanger body, arms attached to the hanger body that can be unlatched and swung to a horizontal position, and a latching system to hold the arms in place. Several conventional hangers can be attached on each arm, allowing clothing to be hung by hangers on the device in an organized fashion, such as by outfits. In addition, the invention provides for vertical positioning of the arms with conventional hangers hung on the arms, which allows a compression of the clothing on the conventional hangers and efficient space saving. The hanger body of the invention also includes attached c-shaped accessory holders that allow easy organization and retrieving of accessories.

Most clothing organization systems poorly utilize all available space. The typical "bar and hanger" system requires hangers to be spaced horizontally, leaving sufficient space between hangers to accommodate clothing or accessory items. This typically does not allow for effective use of vertical or horizontal space within the closet or other storage space. In addition, most clothing organization systems do not allow for the "compression" of clothing.
More advanced clothing organization systems typically cause the user difficulty in storing and retrieving items. Typically the clothing items must be rearranged in some manner to facilitate storage and retrieval of some or all items.
Further, clothing storage systems are not generally designed so that entire "outfits" of clothing can be stored together. This causes the user to have to search through multiple hangers to retrieve all clothing and accessories to complete their "outfit".
The prior art on hanging devices includes several patents. U.S. Pat. No. 1,743,234 to Porter includes a clothes hanger (FIG. 3) with horizontal arms that are downwardly pivotable into an extended horizontal position. The arms are located below a hook. The arms also include notches for receiving shoulder straps of women's gowns. The device of Porter does not include a hanger having a plurality of hang locations, such as holes, for fixedly holding conventional hangers, accessory holders, or an attachment point for chaining together hangers; in addition, the device of Porter does not allow clothing on the arms to be compressed by pivoting the arms upward.
U.S. Pat. No. 1,937,911 to Pajeau provides a necktie holder having arms that pivot downward to an extended position. The arms are physically configured such that garments can only be draped over the arms as extended. The device of Pajeau does not include a hanger having a plurality of hang locations, such as holes, for fixedly holding conventional hangers, accessory holders, or an attachment point for chaining together hangers; in addition, the device of Pajeau does not allow clothing on the arms to be compressed by pivoting the arms upward.
U.S. Pat. No. 4,730,737 to Robinson shows a clothes hanger having a hook, a pair of arms upwardly pivotable into an extended position, and a latch mechanism to secure the arms in a horizontal extended position. The arms are configured as elongated parallelepipeds having top, bottom, and side walls. The bottom wall has an elongated slot, wherein modified conventional hangers extend down through the slot. The hangers have been modified by having the conventional hanger hook replaced with a sphere, which is in turn retained inside of the arm. The device of Robinson does not include a hanger having a plurality of hang locations, such as holes, for fixedly holding conventional hangers, accessory holders, or an attachment point for chaining together hangers; in addition, the device of Robinson does not allow clothing on the arms to be compressed by pivoting the arms upward.
U.S. Pat. No. 5,405,065 to Olson includes a hanger having a center support member and a base having a plurality of arms being pivotally coupled thereto. The arms pivot downward to an extended horizontal position. The device of Olson does not include a hanger having a plurality of hang locations, such as holes, for fixedly holding conventional hangers, accessory holders, or an attachment point for chaining together hangers; in addition, the device of Olson does not allow clothing on the arms to be compressed by pivoting the arms upward.
It thus appears that there is a need for a clothing device, method, and system for clothing organization that overcomes the problems of the prior art. These problems include poor utilization of vertical and horizontal space in closets, lack of use of compression of clothing, difficulties with retrieving stored clothing, and failure to facilitate organized storage of clothing, such as in groups or outfits, using a hanger having a plurality of hang locations, such as holes, for fixedly holding conventional hangers, accessory holders, an attachment point for chaining together hangers, or a method and system to allow clothing on the arms to be compressed by pivoting the arms upward.

Device, method, and system for clothing organization


A zoom lens system includes, in order from an object side to an image side, first to fifth lens groups respectively having negative, positive, negative, positive, and positive refractive power. During zooming from a wide-angle end to a telephoto end, the second and third lens groups are moved independently toward the object side with spacing therebetween increased and that between the first and second lens groups decreased. The following condition is satisfied 1.05≦(fW·LW)/(fT·Y)≦1.53, wherein fW and fT are focal lengths of the zoom lens system at the wide-angle end and the telephoto end, Y represents a maximum diagonal length of an image plane, and LW represents a total length of the zoom lens system at the wide-angle end which is defined as a distance from the vertex of a first surface of the first lens on the object side to the image plane.

1. Field of the Invention
The present invention relates to a zoom lens system, and particularly to a small-size and low-cost zoom lens system for forming a real image on a digital or non-digital image pickup device of a camera.
2. Description of Prior Art
In recent years, most electronic devices, such as mobile phones, personal digital assistants (PDAs) and notebook computers, have been integrated with a photographic lens module for effecting the photographic function. Such a photographic lens module is generally required to be small in size and light in weight for portability, while providing a high level of image resolution. To satisfy these requirements, a conventional photographic lens module generally consists of three lens groups.
With the development of semiconductor technology, aspheric lens elements have been widely used in a photographic lens module. Conventionally, a photographic zoom lens system generally employs three lens groups in a negative-positive-positive refractive power configuration, wherein two of the three lens groups are movable for realizing zooming. However, the movement ranges of the two movable lens groups are relatively large, and the imaging performance dramatically varies with the increase of zoom ratio. To overcome these disadvantages, a zoom lens system consisting of four lens groups has been introduced. However, the employment of four lens groups leads to increase in the number of constituent lens elements and thus increase in manufacturing costs. Therefore, how to provide a high-resolution image with a minimum number of the component lens elements so as to still satisfy the compactness requirement is a challenge to be addressed in the art.
Hence, an improved zoom lens system, which is compact in size and low in cost while ensuring a high level of image performance, is desired to overcome the above problems encountered in the prior art.


An ink-jet printing apparatus which is capable of maintaining a predetermined clearance between a printing surface of a printing object and an ink-jet head, includes a printing object mounting portion, on which the printing object is mounted, an ink-jet unit provided so as to be capable of relative movement in an opposing direction with respect to the printing object mounting portion, and mounting an ink-jet head which can oppose the printing surface of the printing object, shifting means for shifting the ink-jet unit mounting portion relative to the printing object mounting portion in the opposing direction, and a clearance adjusting sensor provided at the side of the ink-jet unit mounting portion so as to be capable of contacting the printing surface of the printing object. The shifting means is driven in a direction where the clearance adjusting sensor is caused to to contact the printing surface of the printing object, the shifting means then is driven in the opposite direction when the clearance adjusting sensor comes into contact with the printing surface of the printing object, and relatively shifting the ink-jet unit mounting portion is shifted relative to the printing object mounting portion in a direction where the clearance adjusting sensor moves away from the printing surface of the printing object by a predetermined magnitude.

1. Field of the Invention
The present invention relates to an ink-jet printing method and an ink-jet printing apparatus which can maintain a clearance between a printing surface and an ink-jet head and attitude of the ink-jet head, for printing objects of various thickness.
2. Description of the Related Art
In an ink-jet system, ink droplet is ejected from ink ejection openings formed in an ink-jet head toward a printing surface of a printing object for printing a desired information on the printing surface of the printing object. Therefore, it is important for assuring satisfactory printing quality to maintain the clearance between the ink ejection openings of the ink-jet head and the printing surface of the printing object.
Conventionally, since sheet form paper having a thickness of about 0.15 to 0.2 mm or the like is exclusively considered as the printing object, it has been sufficient to mechanically set the clearance between the ink ejection openings of the ink-jet head and the printing surface of the printing object for enabling printing on the paper of the like or typical thickness.
Printing apparatuses having mechanisms for adjusting distance between the ink-jet head and the printing object in accordance with the various kinds of the printing objects also are know. However, the adjustable range is merely set to accomodate the thickness of paper, such as a cardboard or the like, at the maximum. Namely, there has been no printing apparatus which can appropriately adjust the clearance between the ink-jet head and the printing surface of the printing object for a variety of printing objects, such as timber, resin, metal and so forth.
In the recent years, study has been made to perform printing of desired image information on a cloth or so forth, or to perform application of an etchant on a metal plate and so forth for forming a printing plate or so forth, utilizing the feature of an ink-jet system, with timber, resin or metal.
To perform ink-jet printing for such wide variety of printing objects, it is inherently required to provide a mechanism for adjusting the clearance between the ink ejection opening of the ink-jet head and the printing surface of the printing objects. In view of this, as is well known from Japanese Patent Application Laid-open No. 219520/1989, there have been proposed ink-jet printing apparatuses which incorporate mechanisms for adjusting clearances between the ink ejection openings of the ink-jet head and the printing surface of the printing objects.
However, in the case of the ink-jet printing apparatus disclosed in Japanese Patent Application Laid-open No. 219520/1989, a sensor for adjustment of the clearance is constantly held in contact with the printing surface of the printing object, which may form scratch lines or stain the printing surface in some case.
On the other hand, conventional ink-jet printing apparatuses may perform printing or printing objects having a uniform thickness. Thus, for a printing object which has a variable thickness, such as a wedge shaped printing object, printing on the printing surface has been considered impossible unless a certain jig is employed.
Furthermore, in the case of special printing objects other than paper, such as timber, metal and so forth, the operator has to position the printing object relative to a predetermined position of the ink-jet printing apparatus. However, conventional ink-jet printing apparatuses have not been designed in consideration of such special printing objects, and thus have no appropriate positioning device. Therefore, some measurement has been required.

Ink-jet printing method and apparatus therefor


Temporary credit card information is automatically obtained and input to online credit card purchases allowing users to protect their actual credit card information from interception while shopping online.

1. Field of the Invention
The present invention relates to computer systems. More particularly, the present invention relates to the automatic generation of temporary credit card information for an online credit card transaction.
2. Description of Related Art
Currently some credit card users can open a web browser, login to their bank's web site over a network, such as the Internet, and manually request generation of a temporary credit card number for use in making an online purchase. When the temporary credit card number is returned to the user, the user then manually inputs the temporary credit card number obtained from the bank's web site into the online purchase transaction. This process is time consuming and typically requires a user to open another web browser, which leads the credit card user to not request a temporary credit card number.

Automatic generation of temporary credit card information


Methods and apparatus are provided which decrease the amount of movement likely to occur during processing of a substrate. In particular, a horizontally supported dielectric panel is subjected to a series of processing steps during which the panel is heated, cooled, or maintained at a fixed temperature so as to a achieve a 2 to 1 reduction in material movement during subsequent processing. It is contemplated that application of the disclosed methods to a dielectric panel will be particularly beneficial when application is accomplished prior to laser drilling and sputtering the panel.

The field of the invention is substrate processing.
When subjecting thin polymer substrates used in the fabrication of IC packages, printed circuit boards, and multi-chip modules to processing steps which raise the temperature of the substrates movement of the substrate material will frequently occur. Such movement can cause difficulty in positioning and aligning of components during processing.
As an example, in a polyimide film substrate having lased vias, the position of the vias may change when the film undergoes increases in temperature. Such increases and resultant changes are likely to occur when a conductive material is sputtered onto the film. Thus, particularly in regard to dielectric materials, which are to be subjected to sputtering and/or lamination, there is an ongoing need to improve processing to reduce the amount of material movement, which occurs during processing.
Methods and apparatus are provided which decrease the amount of movement likely to occur during processing of a substrate. In particular, a horizontally supported dielectric panel is subjected to a series of processing steps during which the panel is heated, cooled, or maintained at a fixed temperature so as to achieve a 2 to 1 reduction in material movement during subsequent processing. It is contemplated that application of the disclosed methods will be particularly beneficial when application is accomplished prior to laser drilling, sputtering, and laminating a substrate.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.

Removing inherent stress via high temperature annealing


An auto-adjustable directional drilling apparatus comprises: a drive-shaft housing; a drill collar coupled to the drive-shaft housing; a drive shaft passing through the drive-shaft housing and the drill collar; an active stabilizer fixed to the drive-shaft housing and movably coupled to the drill collar; a sliding assembly comprising a base support fixed to the drill collar and a sliding base coupled to the drive-shaft housing, wherein the base support defines a slide way and the sliding base is slidably disposed in the slide way; and an actuating module coupled to the sliding base to drive the sliding base to slide along the slide way. An auto-adjustable directional drilling method is also disclosed.

This invention relates generally to an auto-adjustable directional drilling apparatus and method.
The exploration and production of hydrocarbons from subsurface reservoirs have been done for hundreds of years. Hydrocarbon recovery operations typically utilize a drill bit attached to a drill pipe to bore through an onshore or offshore subterranean rock formation until the subsurface reservoir is reached. Usually, the drill pipe is uncontrollable and only straight drilling operations are allowed, which makes it more difficult to change the drilling direction along an expected trajectory to reach the subsurface reservoir. For the directional drilling system in the art, a plurality of trip-in and trip-out operations are usually performed, and the direction of the drill pipe is manually adjusted. This kind of direction adjustment process is complex and inefficient.
Therefore, it would be desirable to provide a new and improved apparatus and method to allow a directional downhole drilling operation.

Auto-adjustable directional drilling apparatus and method


A fabrication method of a solar cell, the method includes doping a silicon substrate having a first conductive type impurity with a second conductive type impurity, the second conductive type impurity being opposite to the first conductive type impurity, and thereby forming an emitter layer at a front surface part of the silicon substrate, forming an antireflection film on the emitter layer, forming a front electrode on the antireflection film, forming a rear electrode on a rear surface of the silicon substrate, and forming a back surface field layer at a rear surface part of the silicon substrate, the back surface field layer having a concentration of the first conductive type impurity that is higher than that of the silicon substrate, the back surface field layer having a different concentration of the second conductive type impurity from that of the emitter layer.

Field of the Invention
The present invention relates to a solar cell and a fabrication method thereof, and more particularly, to a fabrication method of a silicon solar cell, especially, a slim-type solar cell capable of providing a high efficiency at economical unit costs by improving process conditions suitable for a slim-type silicon substrate.
Description of the Related Art
Recently, due to problems such as a rapid rise in oil prices, an environmental problem of the earth, exhaustion of fossil energy, waste treatment in nuclear power generation, location selection according to construction of a new power plant, etc., interest in renewable energy has increased and among others, research and development for a solar cell, which is a pollution-free energy source, has actively proceeded.
A solar cell is advantageous in view of being pollution-free, being a sustainable resource, having a semi-permanent life span, etc., and being expected as a source of energy to allow human beings to ultimately solve the energy problem, without adversely affecting the environment.
Solar cells may be typed as a silicon solar cell, a thin film solar cell, a dye sensitized solar cell, and an organic polymer solar cell, etc., according to their constitutional material. In particular, a crystalline silicon solar cell makes up a majority of the total production of the solar cells in the world over. The crystalline silicon solar cell has a higher efficiency compared to that of other solar cells, and a technique to lower the unit cost of manufacturing crystalline silicon solar cell has continuously progressed, such that the crystalline silicon solar cell may be referred to as the most popular type of solar cell.
Solar cells are generally fabricated to include a p-n junction interface by forming an n-type semiconductor layer on a front surface of a p-type silicon substrate. The n-type semiconductor layer formed on the front surface of the p-type silicon substrate acts as an emitter, wherein an antireflection film of silicon nitride or silicon oxide is coated thereon, and then electrodes are wired in such a way to minimize reflection of light.
Recently, studies that allow the solar cells to have a high photovoltaic efficiency by improving a structure of the emitter in a portion where the front electrode of the solar cell is wired or by controlling a production process of the solar cells have been made.

Solar cell and fabrication method thereof


A process of freezing a belt of encapsulated ice substitute is provided. The process for freezing the ice substitute belt generally includes the steps of preparing a capsule belt with a plurality of capsules, each capsule containing a thermal controlling agent which is a liquid in a predetermined temperature range; preparing a brine including a cruciferous oil, salts and a glycol and cooling the brine; feeding the belt into an apparatus which contains the cooled brine and passing the belt through the brine; adjusting the speed to the extent sufficient for the thermal controlling agent to become solidified. The travelling speed of the ice substitute belt is adjusted depending on the composition of the thermal controlling agent.

1. Field of the Invention
This invention relates generally to an apparatus for freezing an encapsulated ice substitute and a process for freezing such ice substitutes using the invented apparatus, and in particular, to a process for freezing a capsule belt having a plurality of rows of capsules, each of which contains a thermal controlling agent.
2. Description of the Related Art
The use of ice or dry ice as a coolant material serves to preserve organic material and inhibits the growth of many harmful micro organisms.
The major drawback to using ice as a coolant material is that it melts. If the ice is used as a packing material, the space taken up by the ice when melted will be less than when it is frozen, so that it will no longer be an effective packing material. The melted ice is easily contaminated by microorganisms and, since it will be in intimate contact with the products it is intended to protect, these are also liable to become contaminated. The products may also be damaged by getting wet. The melted ice will also allow the products to move or slosh around in the container, risking damage by impact with the walls of the container.
Dry ice has similar problems in that it sublimes into gaseous CO.sub.2 with time. The gas must be dissipated and, with the solid CO.sub.2 gone, the product will no longer be packed against movement in its container. Also both ice and dry ice can be used only once, adding to the expense of such thermal storage.
U.S. Pat. No. 4,931,333 discloses a method for making an ice substitute which is an improvement over known coolants such as ice and dry ice. According to that invention, the ice substitute comprises a plurality of capsules each having a flexible outer skin containing a thermal controlling agent which can maintain a predetermined temperature range for an extended period of time. The thermal controlling agent contained in the capsules is a eutectic solution which has the capacity to absorb or release heat with little or no change in temperature while in the process of changing from one physical state to another, e.g. solid to liquid or vice versa. The capsules must first be charged with the eutectic solution and frozen to the phase change temperature or lower before being subjected to the intended use. However, charging or freezing such ice substitute to the phase change temperature is costly and time consuming because the process can take up to 20 hours using the conventional blast freezing method. Moreover, the equipment for blast freezing the ice substitute is large and inconvenient to operate.
Methods for quick freezing vital body fluids such as sperm, eggs, zygotes, blood and the like, for freezing human tissue and organs, and for freezing other biological materials are known.
U.S. Pat. No. 4,401,909 discloses a method of freezing fishery products. The method includes the steps of preparing a brine containing rapeseed oil, propylene glycol, calcium chloride and water, cooling the brine and immersing the seafood in the cooled brine until it is frozen. A process for quick freezing of meat such as beef, poultry, pork, fish and the like in a similar brine is disclosed and claimed in U.S. Pat. No. 4,654,217 issued to the same inventor.
U.S. Pat. No. 4,657,768 discloses a freezing method for perishable foods which includes placing a perishable food in a heat conducting container. The opposite surface of the heat conducting container is then placed into contact with a cooled brine or a liquified gas. Accordingly, the perishable food is frozen quickly without immersion of food in the cooled brine or liquified gas.
U.S. Pat. No. 4,689,963 relates to a method of freezing foods, in which a layer of a rapeseed oil containing brine is placed in the heat conducting container along with the perishable food.
U.S. Pat. No. 4,840,034 discloses a method of freezing body fluids for extended storage. The method includes the steps of preparing a brine including a suitable oil, generally a cruciferous oil; cooling the brine to a temperature between about -22.degree. and about -43.6.degree. F. The brine generally includes a glycol, a salt and water in addition to the suitable oil.
U.S. Pat. No. 4,840,035 discloses a method of freezing tissue for cytological or histological examination. The method uses a brine similar to that disclosed in U.S. Pat. No. 4,840,034.
U.S. Pat. No. 5,001,047 also discloses a method to chill human organs and maintain the viability of the organs, employing a brine similar to that used in U.S. Pat. No. 4,840,034.
There is no teaching or suggestion in any of these patents that these processes can be used to make ice substitutes such as capsule belts or sheets in a convenient and economical fashion. The inventor has made this discovery which presently speeds up the process and markedly reduces the cost. Accordingly, it is desirable to provide a process for quick freezing ice substitutes.


A method and system is provided for securing micro-architectural instruction caches (I-caches). Securing an I-cache involves maintaining a different substantially random instruction mapping policy into an I-cache for each of multiple processes, and for each process, performing a substantially random mapping scheme for mapping a process instruction into the I-cache based on the substantially random instruction mapping policy for said process. Securing the I-cache may further involve dynamically partitioning the I-cache into multiple logical partitions, and sharing access to the I-cache by an I-cache mapping policy that provides access to each I-cache partition by only one logical processor.

Current microprocessors employ an instruction cache (I-cache) to increase the performance of a system. An I-cache stores the most frequently executed instructions and provides the processor easy and fast access to these instructions. While increasing the performance of the system, I-cache architectures also create several security weaknesses.
One security weakness in conventional implementations of I-cache structures involves shared I-cache units in simultaneous multi-threaded (SMT) and/or multi-core systems, wherein I-cache units are shared between different logical or physical microprocessors (FIG. 1). If two or more processes are executing simultaneously on the same system and if the I-cache is shared between these processes, then a malicious process can indirectly observe the execution of security critical applications and discover confidential values based therein by analyzing I-cache modifications.
Another security weakness in conventional implementations of I-cache structures involves instruction mapping. The mapping process (mapping policy) is performed when a new instruction entry is to be written to I-cache, or an existing I-cache entry needs to be searched in I-cache. The mapping process decides where to store, and look for, I-cache entries in the I-cache.
In typical processor architectures, a particular instruction can only be stored in a particularly small set of I-cache locations in a strictly deterministic way. In other words, it is trivial to find out which locations of an I-cache can store a particular instruction. Due to this predictability, a malicious process can determine where a specific security-critical instruction can be found in I-cache and thus observe the execution of such an instruction. As such, the malicious process can discover when a process executes critical instructions, and, therefore, reveal the execution flow. The execution flow can expose the secret values used in the process.

Method and system for securing instruction caches using substantially random instruction mapping scheme


A motor for a compressor, and a reciprocating compressor having the same, are provided. A winding coil may be formed by removing a bobbin from the winding coil, and then coating an insulating material on an outer circumferential surface of the winding coil, to allow heat and moisture generated by the winding coil to be emitted to outside and provide enhanced performance and reliability. As a bobbin is removed from the winding coil, a coil line may be wound on the removed portion of the bobbin to enhance an occupation ratio by the coil line on the same area, and thus enhance efficiency of the motor. An elastic member or an adhesive may be inserted or applied into a space between the winding coil and a coil insertion groove of an inner stator to minimize vibrations of a coil line. The insulating material, which is in the form of powder, may melt while the coil line is adhered as the self-bonding material melts, forming a coating layer. Accordingly, the winding coil may be easily fabricated, and fabrication costs of the winding coil may be reduced.

Field
This relates to a motor for a compressor and a reciprocating compressor having the same.
Background
A motor applied to a compressor may include a winding coil wound on a stator, and a magnet installed at a mover. The motor may be operated as the mover performs a rotary motion or a reciprocal motion between the winding coil and the magnet.
The coil may be formed in various manners according to a type of a motor. For example, in a rotation motor, the coil may be wound on a plurality of slots formed on an inner circumferential surface of the stator, in a concentrated winding manner or in a distributed winding manner. In a reciprocating motor, a winding coil may be formed as a coil line is wound in a ring shape, with a plurality of stator sheets insertion-coupled to an outer circumferential surface of the winding coil in a circumferential direction. In the reciprocating motor, the winding coil may be formed by winding a coil line on a bobbin formed of a plastic material and having a ring shape.

Motor for compressor and reciprocating compressor having the same


When stopping operation of an electric power steering apparatus, a motor relay is kept in an on-state even after a power supply relay is in an off-state. A drive control portion sets a target value of a d-axis current to a value other than zero and sets a target value of a q-axis current to zero, and performs a processing same as that at the time of rotating a motor. MOS-FETs contained in a motor driving circuit are controlled such that each of driving currents of the two phases or more is not zero and the brushless motor does not rotate even supplied with these driving currents. Electric charge accumulated in a capacitor is discharged via the MOS-FETs each in an on-state, a motor relay and the windings of the brushless motor. The electric charge accumulated in the capacitor may be discharged via the excitation coil of the motor relay.

Conventionally, electric power steering apparatuses are employed in each of which an electric motor is driven in accordance with a steering torque applied to a steering wheel by a driver to thereby apply a steering assist power to the steering mechanism of a vehicle. Although brush motors have been widely employed as the electric motors of the electric power steering apparatuses, in recent years brushless motors are also employed in view of the improvement of reliability and durability and the reduction of inertia etc.
FIG. 4A is a circuit diagram of a motor control circuit contained an electric power steering apparatus of a related art. In FIG. 4A, a three-phase brushless motor 90 is employed in order to generate a steering assist power to be applied to the steering mechanism of a vehicle. Further, a motor driving circuit 93 having six MOS-FETs (Metal Oxide Semiconductor Field Effect Transistors) is employed in order to supply a three-phase driving currents (U-phase current, V-phase current and W-phase current) to the brushless motor 90.
A power supply relay 91 selectively couples a power supply to the motor control circuit. A motor relay 94 selectively couples the motor driving circuit 93 to the brushless motor 90. Each of the power supply relay 91 and the motor relay 94 is turned on when the electric power steering apparatus is operated and turned off when the electric power steering apparatus is stopped.
The six MOS-FETs contained in the motor driving circuit 93 are controlled by a PWM (Pulse Width Modulation) signal output from a drive control portion (not shown), and the motor driving circuit 93 outputs three-phase driving currents which phases differ by 2π/3 from one another and each changes in a sine wave manner. When the brushless motor 90 is driven in this manner by using the PWM signal, the current flowing into the motor driving circuit 93 from the power supply changes largely in a short time and so a current ripple appears. Thus, in order to absorb the current ripple, a capacitor 92 is provided between two power supply lines. The capacitor 92 accumulates electric charge and discharges the electric charge thus accumulated when the current flowing into the motor driving circuit 93 from the power supply is insufficient, whereby the current ripple can be absorbed.
In the electric power steering apparatus of the related art, at the time of stopping the operation thereof, all the six MOS-FETs contained in the motor driving circuit 93 are turned off and thereafter each of the power supply relay 91 and the motor relay 94 is turned off. In this case, it is necessary to discharge the electric charge accumulated in the capacitor 92. To this end, in the motor control circuit shown in FIG. 4(a), a resistor 95 acting as a discharge circuit is provided between the two power supply lines. Thus, the electric charge accumulated in the capacitor 92 is discharged via the resistor 95 after each of the power supply relay 91 and the motor relay 94 is turned off. Alternatively, a circuit formed by connecting the resistor 95 and a switch 96 in series may be provided as the discharge circuit (see FIG. 4B). In the motor control circuit shown in FIG. 4B, the switch 96 is turned on after each of the power supply relay 91 and the motor relay 94 is turned off.
The electric charge accumulated in the capacitor 92 is discharged at the time of turning the power supply off because, at the time of performing a failure inspection of the power supply relay 91 when the power supply is turned on next, the failure inspection cannot be performed correctly if the capacitor 92 still accumulates the electric charge.
The following technique is known as to the motor control circuit of the electric power steering apparatus. A patent document 1 describes that each of three signal lines for supplying a driving current to a three-phase motor is provided with a semiconductor switching element. A patent document 2 discloses an electric power steering apparatus having a motor relay.                [Patent Document 1] JP-A-2006-21645        [Patent Document 2] JP-A-2004-330877