A fastener system mounts a pouch onto a shirt or other clothing article, wherein the pouch provides a receptacle aperture into which a fastener is placed with its flanges positioned on opposing sides of the aperture. The cloth to which the fastener is mounted is gripped between the fastener and the aperture and is locked into place by a U-shaped clip. The flanges are made oblong in shape so that the narrow orientation of the flanges easily pass through the aperture, but the longer orientation cannot. Flats may be applied to both aperture and the fastener so as to assure an orientation in use wherein the fastener cannot disengage from the pouch.

1. Field of the Present Disclosure
This disclosure relates generally to a system for mounting a pouch to a garment at any selected location and more particularly to a fastener for enabling such a system.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Splane, Jr., U.S. 2003/0014844, discloses a removable storage device to enable storage of personal articles on the person of a user. The device includes a pair of snap fit elements. One element includes a recess for receiving a portion of the other element as a snap fit therein so as to permit a portion of an article of clothing worn by the user to be captured between the elements when the elements are snap fit together to thereby removably affix the elements to the article of clothing. One of the snap fit elements includes a support member or arrangement (e.g., a D-ring or a pocket) for supporting a personal article.
Butler, U.S. Pat. No. 1,682,771, discloses a separable button, a base, a shank formed on one face of the base and formed with front threads for its entire length, and over which a piece of fabric is adapted to be disposed, a split resilient ring encircling the fabric covered shank at the juncture of the shank with the base, a head provided with a threaded socket in the inner side thereof, and an internally threaded collar formed on the inner side of the head and extending outwardly therefrom around the socket, the fabric covered threaded shank being removable secured in the socket and collar.
Sperling, U.S. Pat. No. 3,865,290, discloses a tennis ball holder is comprised of a lightweight, vacuum-formed, concave plastic shell having a plurality of fingers which grip the ball to retain the ball within the shell. The rear wall of the shell is generally flat and contains a keyhole. In use, the holder is placed with its rear wall against the outside of the player's clothing at a convenient place. Then a flat plate is positioned underneath the clothing opposite the holder. The plate has a key arranged to project into the keyhole along with the fabric and lock there so as to securely anchor the holder and the ball contained therein to the player's clothing, freeing his hands for play.
Gillis, U.S. Pat. No. 4,308,647, discloses a clip is provided which is adapted for fastening onto a flexible web such as a sheet of fabric. The clip is particularly adapted for fastening the fabric of a tent to supporting poles or stakes or for fastening webs together.
Devenny, U.S. Pat. No. 4,559,675, discloses an invention that is a support for fastening a decorative object such as a flower or corsage to an article of clothing comprising a pair of elements having cooperative shapes such that one clamps into the other, from one side thereof. A decorative object is secured to one of the elements. Accordingly, one of the pair of elements can be clamped into the other from opposite sides of the article of clothing, clamping and catching the article of clothing therebetween and securing it thereto.
Hooper, U.S. Pat. No. 4,985,968, discloses a decorative body member that includes a safe and harmless separable, interlocking fastening device for engaging a portion of a garment therebetween. In one embodiment, an elongated ribbon is attached at one end to the body member and at the other to a pacifier, teething ring, or toy, to avoid loss. The fastener includes a circular pattern of fingers or prongs (female element) extending from the rear surface of the body member. The male element is a disk which is received within the fingers with the fabric therebetween. The disk is sufficiently large to prevent swallowing, and preferably includes an aperture through the center thereof to provide for passage of air if the disk should become lodged in the mouth or inadvertently swallowed.
Maxwell-Trumble et al., U.S. Pat. No. 5,655,271, discloses a clothing accessory that includes a molded plastic plate and a molded plastic ring. The periphery of the plate is provided with a first engagement surface and the interior of the ring is provided with a second engagement surface. The relative dimensions of the plate and the ring are chosen such that the fabric of an article of clothing can be engaged between the first and second engagement surfaces. More specifically, when the ring is placed on one side of a fabric and the plate is placed on the other side of a fabric, the plate and ring may be pressed together so that the plate is frictionally engaged inside the ring by the fabric of the clothing. According to a presently preferred embodiment, the engagement surfaces are V-shaped. I.e. one of the surfaces is a concave V-shaped groove and the other is a convex V-shaped edge. Other preferred aspects of the invention include providing a peripheral lip on the plate which extends substantially orthogonal to one side surface of the plate to define an image receiving area. According to the invention, a photograph, hologram or other decorative indicia is attached to the plate by providing the indicia on a material which is attached to the plate with an adhesive. Preferably, the material is a self-adhesive, peel and stick material. A kit according to the invention, includes a plate, a ring, and a plurality of self-adhesive labels, each bearing different decorative indicia.
Denison, U.S. Pat. No. 5,926,920, discloses a snap-in adapter system that includes an interior piece having a circular interior face and a short cylindrical side wall forming a cylindrical recess, the recess having an interior diameter. The system also includes an exterior piece. The exterior piece has a circular exterior face with a diameter essentially equal to that of the diameter of the recess of the interior piece. The exterior piece also has a cylindrical projection. Also provided is an attachment means.
Fong, U.S. Pat. No. 5,940,942, discloses a fabric holder to secure a plurality of fabrics together. The apparatus comprises two pieces, a male bottom piece and a female top piece which interlock to secure the fabric.
Chen, U.S. Pat. No. 6,223,399, discloses an adornment clamping device which is able to secure the adornment to the base of an item. The device has an elongate bar securely connected with the base by means of a neck, an adornment having a through hole defined to allow the elongate bar to be inserted there through and having a press fit therewith and a slit defined to communicate with the through hole, such that when the elongate bar extends through the through hole of the adornment, the adornment is able to be secured by the press fit between the protrusion formed on the neck and the slit.
The related art described above discloses numerous two-part fastener for wedging a cloth garment therebetween for mounting an item on the garment. However, the prior art fails to disclose an integral fastener with two flanges that is mountable in an aperture of the item to be mounted and which secures the item on the garment. As well, the prior art fails to teach a locking element that is engaged with the fastener after it is mounted. Finally, the prior art fails to teach the use of an elongated flange that may be preferably biased in a position where it is impossible to disengage from the item being attached to the garment. For these reasons, the present disclosure distinguishes over the prior art providing heretofore unknown advantages as further described in the following summary and detailed description and illustrated in the attached drawing sheets.


While a nitrogen-doped gallium phosphide epitaxial layer in an epitaxial wafer as a material of light-emitting diodes is desired to have a high concentration of nitrogen in order to enhance the efficiency of light emission, the present invention provides a reliable and efficient means to accomplish a high nitrogen concentration by the increase of the concentration of ammonia as a nitrogen source in the doping atmosphere to the contrary to the general understanding that increase of the ammonia concentration to exceed a limit rather has an effect of decreasing the concentration of nitrogen doped in the epitaxial layer. The inventive method is based on the discovery that an exponential relationship is held between the growth rate of the epitaxial layer and the concentration of nitrogen in the thus grown epitaxial layer.

1. Field of the Invention
The present invention relates to a method for the preparation of a gallium phosphide epitaxial wafer used in the manufacture of green-emitting gallium phosphide light-emitting diodes. More particularly, the invention relates to a method for growth of a nitrogen-doped gallium phosphide epitaxial layer(s) in which an epitaxially grown gallium phosphide layer(s) is doped with nitrogen as an isoelectronic trap.
2. Description of the Related Art
Devices of semiconductor-based light-emitting diode are manufactured usually from a semiconductor epitaxial wafer having a p-n junction obtained by forming a plurality of epitaxially grown semiconductor layers on a semiconductor substrate. For example, a green-emitting gallium phosphide light-emitting diode is obtained by using a gallium phosphide epitaxial wafer prepared by successively forming an n-type gallium phosphide layer and a p-type gallium phosphide layer on an n-type gallium phosphide substrate.
As is described above, an epitaxially grown layer of gallium phosphide, referred to simply as GaP layer hereinafter, is formed on an n-type gallium phosphide substrate, including a multilayered n-type GaP substrate obtained by forming an epitaxially grown layer(s) of n-type GaP in advance on the n-type GaP substrate, by the method of liquid-phase epitaxial growth such as the so-called melt-back liquid-phase epitaxial growth method.
The melt-back liquid-phase epitaxial growth method above mentioned is a method in which a melt of gallium is put on a gallium phosphide substrate followed by temperature elevation, for example, up to 950.degree. C. so as to melt the surface layer of the GaP substrate into the melt of gallium to form a solution, and then the temperature is decreased at a specified rate, for example, down to 800.degree. C. so that the gallium phosphide dissolved in the melt of gallium is precipitated onto the surface of the gallium phosphide substrate to cause epitaxial growth of a GaP layer.
As is known, GaP is an indirect-transition semiconductor which exhibits only a very low light-emitting efficiency even by forming a p-n junction as such. Accordingly, it is usually practiced to enhance the light-emitting efficiency by doping the n-type GaP layer in the vicinity of the p-n junction with nitrogen which serves as an emission center or, namely, an isoelectronic trap. To say particularly, it is practiced to effect the liquid-phase epitaxial growth of an n-type gallium phosphide layer by passing a doping gas containing ammonia NH.sub.3 over the melt of gallium.
As is shown by the chemical reaction equation (1) below, EQU NH.sub.3 (gas)+Ga(liquid).fwdarw.GaN(solid)+3/2H.sub.2 (gas),(1)
gallium nitride GaN is formed in the melt of gallium by the reaction of gallium and ammonia when a doping gas containing ammonia is passed over the melt of gallium. The nitrogen taken into the melt of gallium in the form of gallium nitride serves as a dopant in the n-type GaP layer as the liquid-phase epitaxial growth proceeds.
The light-emitting diode prepared from a gallium phosphide epitaxial wafer having an n-type GaP layer doped with nitrogen in the above described manner, referred to as the GaP(N) light-emitting diode hereinafter, emits a yellowish green light having a peak wavelength of about 567 nm. FIG. 4 is a graph showing the luminous intensity of a GaP(N) light-emitting diode as a function of the concentration of nitrogen in the nitrogen-doped n-type GaP layer.
In the GaP(N) light-emitting diode, the concentration of nitrogen doped in the n-type GaP layer to serve as an isoelectronic trap is an important factor which determines the light-emitting efficiency of the GaP(N) light-emitting diode. As is shown in FIG. 4, the luminous intensity of the GaP(N) light-emitting diode increases as the concentration of nitrogen is increased within the solid-solubility limit of nitrogen in GaP. Accordingly, the nitrogen concentration in an n-type gallium phosphide layer is increased in the prior art by increasing the concentration of ammonia in the gaseous atmosphere for doping.
FIG. 5 shows the relationship between the concentration of ammonia in the gaseous atmosphere and the concentration of nitrogen in the GaP layer grown under the conditions including a growing temperature decreased from 950.degree. C. to 800.degree. C. and a growth rate of 30 .mu.m per hour. As is understood from FIG. 5, the concentration of nitrogen in the n-type GaP layer increases as the concentration of ammonia in the gaseous atmosphere is increased within the range where the concentration of ammonia in the gaseous atmosphere does not exceed about 0.07% by volume. When the concentration of ammonia is further increased to exceed about 0.07% by volume, the concentration of nitrogen in the n-type GaP layer is rather decreased as the concentration of ammonia is increased.
This phenomenon is the reason for the extreme difficulties encountered in the method of controlling the concentration of nitrogen in the GaP layer by the modification of the concentration of ammonia in the gaseous doping atmosphere, when it is desired to control the nitrogen concentration in the GaP layer at a high level within the region of high concentration of ammonia in the gaseous atmosphere.

Method for growth of a nitrogen-doped gallium phosphide epitaxial layer


A weapons simulator in which the rifle barrel is modified as a cylinder provided with a piston designed for movement therein, to provide a recoil effect. The rifle barrel itself serves as the cylinder and the piston is arranged for sliding motion therein, to provide the recoil effect, while actuating a rifle bolt mechanism. An end of the piston is provided with O-rings to seal it against the inside walls of the barrel. A portion of the barrel inside walls is conically shaped, defining a gap which the O-rings do not seal. Travel of the piston end through this barrel portion enables rapid compressed air exhaustion via the gap, simulating recoil. The conically-shaped barrel portion also guides piston re-entry into the cylinder, during a retraction motion of the rifle bolt mechanism.

Small weapons simulators generally rely on pneumatic cylinder and piston arrangements installed in a weapon for simulating recoil action to enhance the "feel" of simulated firing exercises.
Prior art examples of small weapons simulators include the disclosure of U.S. Pat. No. 4,380,437 to Yarborough, featuring a recoil module based on a pneumatic cylinder and piston installed in a rifle butt. A valve actuated by a trigger allows compressed air to flow into the recoil module (piston), to provide an impulse simulating rifle firing, with live ammunition. The recoil module is a standard, manufactured unit for purchase.
A weapons trainer having a projection screen video system and a simulated weapon is disclosed in U.S. Pat. No. 5,035,622 to Marshall et al, featuring recoil of the simulated weapon provided by pneumatics.
In prior art weapons simulators, the air piston is used to push and pull the bolt mechanism. Since the air piston must release trapped air, its motion is slower than the gun mechanism itself, and thus the recoil feeling is not realistic. A pneumatic trigger mechanism is often used, and this is not a faithful simulation of a real trigger. No "click" is heard, or the hammer is generally eliminated, so the real "feel" of a weapon is absent. Usually some mechanical elements in the trigger mechanism are eliminated or modified.
In addition, the difficulty associated with repairing simulated weapons which utilize a pneumatic cylinder is due to the need to remove the cylinder, which is a time consuming process. Many air connections are needed in these designs, since the air flow is directed to provide two-directional rifle bolt movement, and these air connections complicate the breakdown and re-assembly procedure, making for costly maintenance and repair.
Thus, it would be desirable to provide recoil simulation without installing an external air cylinder for recoil.


Disclosed is a communication device having an automatic reply function and a method for performing automatic reply thereof. The communication device includes a communication module for receiving a communication request signal; a positioning module for generating positioning information according to a current position of the communication device; a vibration detection module configured to detect a vibration of the communication device to generate a vibration signal; and a processing module. In an interval upon the communication module receiving the communication request signal, the processing module is configured to calculate a velocity of the communication device according to the positioning information and calculate an incidence of vibration of the communication device according to the vibration signal. And the processing module is configured to conduct the communication module transmitting a reply message according to a velocity range corresponding to the calculated velocity and an incidence range corresponding to the calculated incidence.

1. Field of the Invention
The present invention relates to a communication device and communication a method thereof, in particular with respect to a communication device having an automatic reply function and a method for performing automatic reply thereof.
2. Description of the Related Art
With the technology progression, electronic products are out with the old to make way for the new, especially, those which are fresher, such as the commonly-used smart mobile phones, are more popular to the public.
Smart mobile phone, which is the so-called Smartphone, is regarded as the collective appellation of a cellular phone installed with better operating capability and function than traditional. At present, most people have one or more smart communication products which not only have the common communication function, but also are carry-on and capable of executing works and performing multimedia function.
The existing smartphone is further capable of providing user with various setting modes, such as normal mode, car mode and so on an so forth which enable the user easily taking a phone call while dealing with matters. If the user is unable to answer the phone call, call forwarding function can therefore be set, so that the incoming call will be forwarded to another gadget or voicemail.
Nonetheless, no matter which mode is set, it is a troublesome matter that manual setting is inevitable to the user. The existing call forwarding function can only forward incoming call to another gadget or voicemail, and results that the caller is unable to realize the reason of the unanswered call, and if the incoming call belongs to an important one or is dialed by relative or friend, the caller may worry about the unknown situation.

Communication device having automatic reply function and method for performing automatic reply thereof

INVENTEC APPLIANCES (PUDONG) CORPORATION

INVENTEC APPLIANCES (SHANGHAI) CO., LTD.

INVENTEC APPLIANCES (NANCHANG) CORPORATION


A method for in-situ aberration measurement in an optical imaging system of lithographic tools. According to the method, a reticle pattern is imaged to form an imaged pattern by transmitting beams through a reticle via the optical imaging system. The imaged reticle pattern is shaped to have plural groups of imaged linewidths. The plural groups of imaged linewidths are measured using either of an image sensor, a CD-SEM and a microscope by modifying the intensity distribution at an exit pupil plane of the optical imaging system. The asymmetry and ununiformity of the imaged linewidths are calculated. Aberrations of the optical imaging system are calculated.

It is known in the prior art that an exposure apparatus carries out the exposure process of illuminating the various patterns on the reticles using the exposure light beams, and transferring the patterns onto the substrates such as wafers, glass substrates, etc. coated with photoresist.
In resent years, semiconductor components become more and more integrated, which requires the circuit pattern to be more precise. As feature size decreases, especially with the use of off-axis illumination and phase-shifted mask, the aberrations are having more influence on the quality of lithography process. Thereby, the in-situ measurement technique for optical imaging system in lithography tools is becoming more and more important.
The process of aberration measurement in an optical imaging system will be described as follows with an example of projection optics. Firstly, position the reticle for aberration measurement on the object plane, and image the pattern formed by the reticle onto the substrate via the projection optics. Then, develop the image on the substrate, and use the Scanning Electron Microscope (SEM) to perform the measurement on the developed image. Finally, calculate the aberrations of the projection optics according to the measurement results. (Prior art 1, Peter Dirksen, Casper A. Juffermans, Ruud J. Pellens, Mireille Maenhoudt, Peter Debisschop. "Novel aberration monitor for optical lithography." Proc. SPIE 1999, 3679, 77-86.)
However, in the abovementioned method, the measurement accuracy is related to the lithographic process, such as coating uniformity and developing uniformity. Moreover, pre-processes such as develop must be carried out before utilizing SEM to measure, which prolongs the process of aberration measurement.
To avoid these problems, a method of wavefront aberration measurement for projection optics is provided by using the Transmission Image Sensor (TIS), i.e. the TAMIS technique. (Prior art 2, Van der Laan, Hans, Dierichs, Marcel, van Greevenbroek, Henk, McCoo, Elaine, Stoffels, Fred, Pongers, Richard, Willekers, Rob. "Aerial image measurement methods for fast aberration set-up and illumination pupil verification." Proc. SPIE 2001, 4346, 394-407.)
The TIS comprises a set of sub-micron isolated spaces and a square hole, both of which have a photodiode close behind them. Wherein, the isolated spaces comprise X-direction isolated spaces and Y-direction isolated spaces. Isolated spaces of different directions are used to detect the image positions of the spaces of different directions. The square hole is used to compensate the intensity fluctuations of the light source. The image position (X, Zx) of the X-direction spaces and the image position (Y, Zy) of the Y-direction spaces are determined according to the output of the photodiodes.
During the measurement, the binary optical reticle for aberration measurement is positioned on the reticle stage, which has marks with similar pattern to the TIS. The TIS scans the aerial image of the reticle mark projected by the projection optics horizontally and vertically by moving the wafer stage, and obtains the image position (X, Y, Zx, Zy) of the mark. Comparing the image position with the ideal position, the displacement (ΔX, ΔY, ΔZx, ΔZy) of the image is obtained. The image positions of all the marks under different NA and σ are measured to get the imaging displacements at different positions in the field of view under different illumination conditions. Then, the corresponding Zernike coefficients of the aberrations can be calculated by employing the TAMIS algorithm. However higher accuracy of aberration measurement is required to meet the development of lithograph technology. So, it has been more and more difficult for the abovementioned measurement techniques to achieve the high accuracy required.

Method for in-situ aberration measurement of optical imaging system in lithographic tools

Shanghai Micro Electronics Equipment Co., Ltd.


A tracking loop of an interpolator based receiver includes clock elements that generate a plurality of clocks to sample a signal from a remote transmitter. The tracking loop includes samplers and voter elements that sample the signal with the clocks and generate samples that comparatively indicate a phase relationship between the signal and the clocks. Based on the comparison of the samples in the samplers and voter elements, the tracking loop either sends phase-shift signals to the clock elements to shift the phase of the clocks to match the phase of the signal, or sends a phase-flip signal to the clock elements to flip the clocks if the phase relationship between the signal and the clocks is about 180°. Once a phase match between the clocks and the signal is established, the tracking loop remains phase locked with the signal and provides a recovered signal.

High speed interfaces typically employ either interpolator based tracking receivers or a more traditional PLL (Phase-Locked Loop) based tracking receivers. Both receivers use a tracking mechanism that tracks a remote transmitter's clock phase. The interpolator based receivers use timing information embedded in data edges of the remote transmitter to align a locally generated clock with the remote transmitter's clock. At start up, the tracking loop of the receiver adjusts the phase of a local clock to match the remote transmitter's clock. When the phase of the local clock substantially matches the phase of the remote transmitter's clock, the receiver locks to the remote transmitter's clock phase. The initial phase adjustment period of the receiver is typically referred to as lock time.
To reduce latency of high speed interfaces, tracking receivers can be designed to reduce lock time. In typical tracking receivers, lock time is proportional to the initial phase error and the granularity of the interpolator (i.e., the size of the phase correction steps). Because the largest lock time occurs when phase error is 180°, fine phase corrections at such a phase error can increase lock time. In contrast, large phase corrections will reduce lock time but may increase the phase error at lock condition.

Lock system and method for interpolator based receivers


Systems and methods for radiation monitoring with a fuel-based liquid scintillant are disclosed. Fuel-scintillant compositions according to this disclosure may serve dual purposes of a fuel to power an engine and a scintillator to detect radiation. For example, fuel-scintillant compositions may be incorporated into a radiation monitoring vehicle that combusts the fuel-scintillant composition to power the vehicle. Further, systems may be configured to detect scintillation events within the fuel-scintillant composition and may be configured to detect weak and/or distance radiation sources.

Radioactive materials and radiation sources can be detected with radiation detectors, commonly scintillation detectors. Scintillation detection requires a special material, a scintillator, that luminesces when excited by radiation. Scintillators may be used in solid or liquid form. Only particular compositions, generally aromatic hydrocarbons, are scintillators in liquid form.
Detection of weak radiation sources (e.g., infrequent radiation events) and/or distant radiation sources generally requires large scintillation detectors for effective detection. Large detectors may be expensive, difficult to build, and/or difficult to move. Additionally, liquid scintillators may include large fractions of undesirable materials.
Hence, there is a need for systems and methods for radiation monitoring that economically may detect weak and/or distant sources and/or do so with less exotic and/or undesirable materials.


An injection controller for an internal combustion engine that suppresses the accumulation of deposits on a nozzle hole of a direct injection valve. The injection controller includes the direct injection valve, which injects fuel into a cylinder, and an intake passage injection valve, which injects fuel into an intake passage. An ECU, which is connected to the direct injection and intake passage injection valves, executes a first fuel injection mode for injecting fuel with the direct injection valve and a second fuel injection mode for injecting fuel with the intake passage injection valve. The ECU switches fuel injection modes from the second fuel injection mode to the first fuel injection mode for a predetermined period when fuel is to be injected in the second fuel injection mode.

The present invention relates to an injection controller for an internal combustion engine, and more specifically, relates to an injection controller for an internal combustion engine provided with a direct fuel injection valve, which injects fuel directly into the cylinder, and an intake passage fuel injection valve, which injects fuel into an intake passage.
Conventionally, certain internal combustion engines are provided with a direct injection valve (in-cylinder injection valve) for injecting fuel directly into the cylinder in addition to a port injection valve for injecting fuel into an intake port of an intake passage (for example, refer to Japanese Laid-Open Patent Publication No. 2002-364409). In such an internal combustion engine, the fuel injection is flexibly switchable in accordance with the engine operation conditions such that fuel injection is performed by only the port injection valve, fuel injection is performed by only the direct injection valve, and fuel injection is performed by both valves.
The direct injection valve includes a nozzle hole for injecting fuel. Since the direct injection valve is exposed to high-temperature combustion gas in the combustion chamber, deposits tend to adhere to the nozzle hole of the direct injection valve. When the direct injection valve is injecting fuel, the nozzle hole is cooled by vaporized fuel. However, when the direct injection valve is not injecting fuel, the nozzle hole is not cooled by vaporized fuel and the temperature of the nozzle hole increases such that deposits accumulate on the nozzle hole. Such deposits obstruct the injection of fuel from the nozzle hole of the direct injection valve. As a result, the shape of fuel mist may change (particle diameter increases) or the amount of injected fuel may decreases so as to be less than the amount required. There is concern in this case that misfire and unsatisfactory combustion may occur.
In the apparatus described in Japanese Laid-Open Patent Publication No. 2002-364409, some of the injected fuel of the port injection valve is allocated to the direct injection valve even during the period of operation in which the port injection valve is used. In this case, the nozzle hole is cooled by the vaporized fuel and the accumulation of deposits is prevented.
In the method for allocating some of the injected fuel of the port injection valve to the direct injection valve described above, when the required amount of injected fuel is relatively low, the portion of the injected fuel allocated to the direct injection valve is also relatively small. Therefore, an adequate cooling effect is not obtained, and the accumulation of deposits is not sufficiently prevented.
When a small amount of injected fuel is required and the fuel allocated to the direct injection valve falls below the appropriate minimum amount (minimum value ensuring linearity of the injected amount relative to valve open time of the injection valve), the direct injection valve cannot inject fuel normally. In this case, there is concern that misfire and unsatisfactory combustion may occur.

Injection controller for internal combustion engine


A color space transformation matrix calculating method is provided that calculates a color space transformation matrix which transforms colors in a first color space to colors in a second color space. The method optimizes a plurality of constant color-space transformation matrices, so that each of the constant color-space transformation matrices is adjusted to transform each standard color in the first color space to each goal color in the second color space, which correspond to each of the standard colors. The method further calculates interpolation functions for each matrix element of a color-space transformation matrix applied for the entire gamut of the first color space, based on the constant color-space transformation matrices.

1. Field of the Invention
The present invention relates to a color adjusting method that optimizes color signals to improve the reproduction of color in an image, and an image processing device applying the method. More particularly, the invention relates to a color adjusting method using a color-space transformation-matrix.
2. Description of the Related Art
Generally, a color space of an image input system, such as an image capturing apparatus, is different from a color space of an image output system, such as a display and a printer. For example, perceived color of a reproduced image, when a captured image is displayed on a monitor, is generally different from that of an original subject. Further, the difference between the perceived colors also depends on the properties of each output device.
Accordingly, color signals based on the sRGB standard which is a standard for the image input devices and image output devices, are generally used at present. The image input device outputs color signals after transforming the obtained RGB signals to signals based on the sRGB standard. Thereby, precise color reproduction is performed as long as the image output devices are compatible with the sRGB standard. Namely, tints quite similar to the original object can be reproduced. A variety of methods for performing color adjustment are known in the art. For example, the reproduced color can be converted to the original color by adjusting the spectrum characteristics of an optical filter, provided in an imaging system, to the sRGB standard or by transforming the RGB signals electronically by a matrix transformation.
Conventionally, multiple linear regression analysis is used to improve the accuracy of color transformation methods that use a color space transformation matrix for electronic color adjustment. Multiple linear regression analysis optimizes the matrix elements of the color-space transformation-matrix by a statistical analysis which considers the relationship between the original color and the reproduced color as a cause and effect relationship. Namely, the matrix elements are obtained by optimizing these elements under the condition that the difference between the signal levels of the predicted reproduced colors, which is obtained by performing a provisional color space transformation matrix operation on the RGB signals from the imaging system, and the signal levels of the original colors, is below or equal to a permissible value. For example, a method that uses multiple linear regression analysis to provide a matrix that transforms RGB signals to XYZ signals of a different calorimetric system is disclosed in the Japanese unexamined patent publication (KOKAI) No. 10-164381.

Color-space transformation-matrix calculating method and image processing device


The present invention relates to a process for the preparation of pyrrole derivatives of the general formula I ##STR1## by reaction of a compound of the general formula III ##STR2## where R, R.sup.1 and R.sup.2 are defined as specified in claim 1, in a Vilsmeier reaction. The reaction is carried out in an easily degradable solvent, the reaction product is isolated with the aid of a water-miscible extractant and is purified by high-vacuum distillation in the short path evaporator.

1. Field of the Invention
The present invention relates to a process for the preparation of pyrrolaldehydes by Vilsmeier synthesis and purification by high-vacuum distillation. Pyrrolaldehydes are valuable pharmacologically active compounds and are described, for example, in EP-A 287 988 and corresponding U.S. Pat. No. 5,043,348. A Vilsmeier synthesis for the preparation thereof is also already specified there.
2. Discussion of Prior Art
The synthesis of relatively large amounts of substances by the Vilsmeier process poses problems with regard to industrial practicability. Moreover, on an industrial scale, the yields are relatively low and the purities of the products do not correspond to the requirements which must be made of a pharmacological active compound. Since, in the reaction itself, large amounts of halogen-containing solvents must be used, there are, in addition, considerable problems in keeping the waste water and exhaust air clean, and also with regard to the general safety at work. The purification of the products by repeated recrystallisation is associated with considerable losses of yield and the use of relatively large amounts of solvent.

Process for the preparation of pyrrole derivates


A modular wind abatement system comprises a plurality of net components, net-to-net connection hardware, net-to-ground anchors and net-to-building anchors. Flexible net-like sheet components are configured and joined into a suitably sized and shaped web fitted in covering relation with a structure, such as a home, building, billboard, motor home, boat, or any other outdoor thing to be protected. Net component sections are joined together to form suitably sized and shaped web using clamp devices. Once formed the web is secured to the ground in at least partial covering relation with the protected structure by suitable ground anchors such that wind forces are transferred to ground anchors. The present invention thus provides a wind abatement device suitable for protecting a wide variety of structures and property from damage resulting from hurricane force winds and windborne debris.

1. Field of the Invention
The present invention relates to wind abatement devices, and more particularly to a flexible wind abatement and impact system for protecting structures, such as buildings and signs, as well as openings within structures.
2. Description of Related Art
The United States has experienced numerous weather-related disasters in the past 20 years that have each caused in excess of $1 billion in damages. In 2004, the State of Florida was subjected to direct hits from multiple hurricanes the combined effect of which resulted in damages of approximately 20 billion dollars. In 2005, hurricanes Katrina and Wilma subjected Florida and the Southern Gulf Coast to devastating damage.
In addition, population growth along the coastline of the United States has resulted in an increased risk to life and property from hurricane related damage. There are approximately 40 million permanent residents along the hurricane-prone coastline of the United States, with areas such as Texas, Florida, and the Carolinas, where hurricanes frequently strike, experiencing rapid population growth. Furthermore, many coastal areas experience substantial but temporary population increases from holiday, weekend, and vacation visitors during hurricane season.
Homes, buildings, and other structures, suffer substantial damage when storm generated winds carrying windborne debris penetrate the structures through window and door openings Hurricane shutters have long been used as barriers to protect window and door openings from the effects of storm generated winds. Equipping homes and other buildings with hurricane protection in the form of storm shutters is one of the most prudent actions one can take to protect life and property.
Accordingly, the background art reveals a number of storm shutters and other devices designed for permanent or removable installation on homes and buildings. Conventional storm shutters typically consist of corrugated metal panels affixed to the outside of a given structure. For example, U.S. Pat. No. 2,878,536, issued to Becker, discloses a shutter structure having overlapping corrugated panels. U.S. Pat. No. 4,333,271, issued to DePaolo et al., discloses a hurricane panel system for covering windows and doors wherein a plurality of corrugated metal panels are arranged in overlapping relationship to provide a protective structure. U.S. Pat. No. 5,345,716, issued to Caplan, discloses a storm shutter system comprising a combination of individual, interlocking modular elements. U.S. Pat. No. 5,852,903, issued to Astrizky, discloses a hurricane shutter comprising a pair of normally open doors that are swingable to a closed position. U.S. Pat. No. 5,911,660, issued to Watson, discloses a storm panel comprising a plurality of interlocking tiles interlocked together by a plurality of dovetail joints.
A significant disadvantage with conventional storm shutter panels is that installation of the panels over all of the window openings prevents light from entering the structure thereby darkening the interior. Accordingly, if power is lost, as often happens during severe storms, the occupants of the structure find themselves in total darkness.
Accordingly, a number of references disclosed in the background art reveal attempts to provide storm shutters that provide sufficient impact resistance while allowing light to enter to building. For example, U.S. Pat. No. 5,918,430, issued to Rowland, discloses a removable storm shield comprising transparent convex panels. U.S. Pat. No. 5,996,292, issued to Hill et al., discloses a perforated shutter system wherein at least one panel is formed of corrugations. U.S. Pat. No. 3,358,408, issued to Cooper et al., discloses an insulated light transmitting panel construction having corrugations in the side edges thereof. U.S. Pat. No. 4,685,261, issued to Seaquist, discloses a removable translucent storm shutter consisting of a ½″ thick polycarbonate sheet in an aluminum channel frame. U.S. Pat. No. 5,595,233, issued to Gower, discloses hurricane shutters formed of transparent, double-skinned panels that are strengthened by rods extending through the end channels. U.S. Pat. No. 5,457,921, issued to Kostrzecha, discloses a storm shutter wherein a plurality of corrugated shatter-resistant and transparent plastic sheets fastened to the structure using a mounting mechanism and fasteners inserted through key-way slots. In addition, U.S. Pat. No. 6,515,555, issued to Madden (a present inventor) discloses light transmitting storm shutter system for homes, buildings and the like. The Madden system provides a combination of corrugated aluminum and clear polycarbonate panels arranged in alternating adjacent and partially overlapping relation over a given window or door opening.
While storm panels are generally effective in protecting building openings, such systems are burdened by disadvantages. For example, storm panel systems are often overly complex, difficult to install, and expensive. One primary problem present with virtually all temporarily installed storm panels is that the panels are generally large and often very heavy, thereby rendering installation a difficult and time consuming task. As a result, many people, including the elderly and disabled, find installing storm panels difficult if not impossible without assistance.
In view of the disadvantages present in the art, the prior art further reveals the existence of alternative flexible wind abatement devices. For example, U.S. Pat. No. 5,937,596, issued to Leeuwenburgh et al., discloses a weather barrier kit is provided comprising double-faced tape used to bond a film to a window frame and a folded and rolled sheet of film having a stiffening band and strip of adhesive across the top. U.S. Pat. No. 5,939,658, issued to Muller, discloses a portable tactical shield system for shielding a doorway or window consisting of an armored curtain and a hook and loop fastening system. U.S. Patent Application No. 2004/0154242, issued to Hudoba, discloses a system for covering an opening in a structure includes a sheet of flexible material having opposed side edges. A thickened area and a pocket are formed at the side edges. A plurality of spaced apertures extend through the thickened area, and a rope is positioned in the pocket. A grommet assembly is positioned in each of the apertures to reinforce the apertures. A plurality of fasteners are carried by the structure and are spaced so that they can extend through the apertures.
While the flexible wind abatement devices revealed in the prior art are lighter in weight than conventional corrugated storm panels and thus have largely overcome some of the limitations referenced above, they are primarily designed and intended to cover relatively small window and door openings largely fail to provide a system that is sufficiently adaptable to secure entire buildings or other property from the destructive effects of hurricane force winds.
In that regard, the background art reveals several attempts directed to providing wind abatement devices capable of securing buildings and structures by essentially tying down the roof. For example, U.S. Pat. No. 5,522,184, issued to Oviedo-Reyes, discloses a net member positioned over the roof of the building structure with cables used to interconnect support beam members with the net to keep the net in place, and anchorage assemblies keep support beam members in place. This system fails to provide protection for the windows or doors. U.S. Pat. No. 5,623,788, issued to Bimberg et al., discloses a roof anchoring system wherein roof-engaging plates are arrayed over the top of a roof and connected by cables. Ground engaging assemblies are provided to anchor the roof-engaging plates to the ground. Bimberg does not provide protection for the sides of the structure. U.S. Pat. No. 5,819,477, issued to Gaffney, discloses a system for securing a building roof using a plurality of lines and ground anchors. Netting material is used to span the lines on the roof U.S. Pat. No. 5,983,572, issued to Laboy discloses a roof tie-down arrangement for preventing damage to a roof by attachment of support members anchored by cables.
The background art, however, fails to disclose a modular wind abatement system sufficiently adaptable to protect a wide variety of real and personal property from hurricane force wind damage. More particularly, the background art fails to provide a wind abatement system adapted for custom installation on any of a wide variety of real property (e.g. buildings and homes) as well as personal property (e.g. boats and motor homes). Accordingly, there exists a need for such a wind abatement system that overcomes the disadvantages and limitations present in the background art.


A method for forming uniform, sharply defined periodic regions of reversed polarization within a unidirectionally polarized ferroelectric material proceeds as a two-step process. First, alignment keys are formed on upper and lower planar surfaces of a unidirectionally polarized ferroelectric material by producing a spaced pair of alignment key shaped domain reversed regions and etching alignment key shaped notches in the upper and lower surfaces where the domain reversed regions intersect the surface planes. These notches, being vertically aligned between the upper and lower surfaces, are then used to align photomasks over a surface coating of photoresist formed directly on the material surface or on SiO2 layers coating the material surface. The photoresist is then patterned and may also be thermally hardened to form a plurality of regularly spaced open strips, through which conducting metal contacts or ion-exchanged regions may be formed or contacts to the ferroelectric surface can be directly made by liquid conductors to produce the desired polarization reversals by application of an electric field at different temperatures of the material.

1. Field of the Invention
This invention relates to a fabrication method for creating patterned domain reversals in ferroelectric materials. The method can be applied to any ferroelectric material.
2. Description of the Related Art
Ferroelectric materials have internal electric dipole moments which can be made to manifest themselves on a macroscopic domain scale without the presence of external electric fields (hence the term "ferroelectric" by analogy with "ferromagnetic" for materials with domain scale magnetic dipole moments). These macroscopic polarizations are responsible for the optical properties of the materials through the important effects they have on the propagation of electromagnetic radiation. When the polarization of such materials is linearly dependent (or only very weakly non-linearly dependent) on the electric field strength of an electromagnetic wave propagating through the material, the effect of the linear polarization is to produce a constant refractive index, which is responsible for modifying the speed of the wave through the material. In such a linear case, an incident oscillating electromagnetic field at frequency ω produces an oscillation of the polarization at the same frequency co which, in turn, produces a re-radiated electromagnetic field also of the same frequency but out of phase with the incident wave. The original incident wave, combined with the phase-varying re-radiated waves along the forward propagation direction of the incident wave, creates a net transmitted wave that moves through the material at an apparently slower speed but same frequency. The speed, v(ω), of the transmitted wave in the crystal, is defined as c/n(ω), where c is the speed of the wave in vacuum (ie., the speed of light) and n(ω) is the index of refraction of the medium which, as indicated, depends on the frequency ω of the wave (ie., the medium is generally dispersive). Another important parameter of the medium is k(ω), the propagation constant of the radiation, which is defined as: k(ω)=2πn(ω)/λ, where λ is the wavelength of the wave in vacuum.
When the polarization of the crystal is made to change by the imposition of an external electric field that is not the oscillating field of the incident electromagnetic wave, then interactions between the wave and the material can occur which are not simply describable by a constant index of refraction that simply changes the wave speed. For example, the so-called electrooptic effect results when the application of a constant electric field is used to rotate the dipole moment directions of a crystal and to thereby change both the speed and the polarization direction of an incident wave.
If the polarization at a position x within the crystal is a non-linear function of the field at that position, the propagation of an electromagnetic wave can be affected in additional ways. For example, the propagation of a wave with frequency ω1 will lead to the propagation of a secondary wave with frequency 2ω1, which is the second harmonic of the wave. If two waves, of different frequencies ω1 and ω2 simultaneously propagate through the non-linear crystal, there will be generated additional waves of frequencies ω1+ω2, ω1−ω2, 2ω1 and 2ω2. Each wave periodically modulates the polarization which the other wave sees and which it sees itself and, as a result, new waves are generated.
When waves at two different frequencies ω1 and ω2 and two different propagation constants k1 and k2 propagate a distance L through a non-linear crystal, one wave (k1) can transfer power to the other wave (k2) through the non-linearity of the polarization. The amount of power transferred after the wave has traveled a distance L in the crystal can be shown to be proportional to: L2(sin x/x)2, where x=(k3−k1−k2)L/2=LΔk/2 and k3 is the propagation constant of the polarization wave. If Δk is not zero, the transfer of power reaches a maximum value when the wave has propagated a distance called the coherence length, Lc, where LcΔk/2=π/2, (ie. Lc=π/Δk). If Δk=0, the incident waves and the polarization wave are said to be phase matched and the power transfer increases along the entire length of the crystal and is proportional to L2, where L is the length of the entire crystal. If Δk is not zero, the maximum power transfer occurs within the coherence length, then goes to zero, then rises again in the next coherence length. In general, the power transfer within the coherence length is the maximum transfer possible, no matter through how many coherence lengths the waves propagate. Since obtaining a phase matched condition is very difficult in practice (it has been obtained using birefringent crystals) and will only occur at particular k values, an alternative approach to maximizing power transfer is through "quasi-phase matching" or QPM. QPM is obtained by changing the phase between the propagating wave and the polarization wave by π/2 every time the propagating wave moves through an additional coherence length. This can be accomplished by rotating the polarization direction within the crystal by 180° in successive coherence lengths. Unlike true phase matching, QPM can be obtained for a wave of arbitrary k value, providing the polarizations in the crystal can be rendered appropriately periodic in successive coherence lengths. Thus, by satisfying the QPM condition, the maximum power transfer is incremented in each successive passage of the wave through a coherence length, rather than falling to zero. Such a periodic rotation of polarization domains (domain reversals) of width Lc is usually accomplished by the application of electric fields, electron beam patterning or proton exchange/heat treatment (of which more will be said in the following) and the process is called "poling." Although quasi-phase matching does not produce the amount of power transfer produced by genuine phase matching (because the factor (sin x/x)2 is 1 for Δk=0, but is 4/π2 for Lc Δk=π/2), it is much better than the non-QPM case. Much inventive effort has been expended in finding ways of rotating crystal polarizations in a periodic manner with the coherence length being the period.
A case of particular interest in modern technology occurs when ω2=2ω1, which is called frequency doubling or second harmonic generation (SHG). Obtaining a meaningful power transfer between an incident wave and its frequency doubled second harmonic allows the production, for example, of coherent green or blue light by the passage of near infra-red radiation from a solid state laser through a non-linear ferroelectric crystal. Since coherent infra-red radiation is easier to produce by laser action than coherent blue or green radiation, being able to obtain the green or blue by SHG is quite important. Such green or blue light is important for reading and writing optical storage disks. The coherence length needed to obtain efficient frequency doubling is given by: Lc=π/(2k1−k2). Note that 2k1−k2 is not zero because of the dispersion of the material, so true phase matching is generally not possible. As noted above, use of QPL by poling non-linear ferroelectric crystals such as congruent lithium niobate (LiNbO3, or CLN) or stoichiometric lithium tantalate (LiTaO3 or SLT) allows frequency doubling of radiation within the entire range of frequencies for which these crystals are transparent: (0.32 microns–5.5 microns) for CLN and (0.27 microns–5.5 microns) for SLT. The following prior art teaches a variety of methods for patterning and reversing polarization domains to achieve QLM in non-linear ferroelectric materials.
Nihei et al. (U.S. Pat. No. 5,424,867), teaches a method for fabricating an optical wavelength converter with a high threshold for optical damage. It is pointed out that a crystal may be damaged by a second harmonic wave having a relatively low power of 2 mW at a wavelength of 477 nm. Within the method, periodic domain reversals are formed on a LiNbO3 substrate which is covered by a thin, transparent conducting film of indium-tin-oxide (ITO). The film then dissipates surface charges formed by the polarization process without, at the same time, producing reflection or scattering which would degrade the signal. Within the method domain reversals within the crystal substrate are accomplished by an electron beam having an energy between 20–30 kV. The period of the domain reversals is set to 4.7 microns which allows a first order period of 946 nm to produce a second order harmonic of period 477 nm.
Yamada et al. (U.S. Pat. No. 5,249,250) notes that the depth of a domain reversal and the width of a domain reversal (pitch) are related so that a narrow pitch (high frequency) results in a shallow depth. A shallow depth reduces the region of the crystal through which the SHG will occur. To solve this problem, Yamada teaches the formation of domain reversed regions by first polarizing the crystal uni-directionally (a single domain), then irradiating the crystal surface with a 15 kV electron beam in a pattern of regularly spaced parallel strips. An important aspect of this method is that the inverted domain structure can be formed without adversely affecting the index of refraction of the crystal.
Nozaki et al. (U.S. Pat. No. 5,395,495) teaches a method of forming domain reversals within a ferroelectric crystal wherein a high resistance layer is first formed on a uni-directionally polarized crystal surface and a charged particle beam is then directed into the crystal through the layer. This method alleviates the problem of forming effective domain reversals in the vicinity of the crystal surface.
Harada et al. (U.S. Pat. No. 5,415,743) teaches a method of forming sharply defined domain reversals that extend through the entire thickness of the ferroelectric crystal. The method teaches the formation of proton-exchanged regions on a unipolarized crystal and then heating the regions by the application of external electric fields. Also taught in the method is the formation of a Ti-diffused region which is also heated by an electric field, forming ion-implanted regions which are heated by an electric field and irradiating selected regions with light, followed by subsequent field treatment. The electric field in each of these methods is provided by a corona discharge.
Harada et al. (U.S. Pat. No. 5,568,308) teaches the formation of domain reversals in a MgO-LN non-linear unipolarized ferroelectric crystal by first proton-exchanging an appropriate region and then applying patterned electrodes to a surface of the crystal and creating an electric field between the electrodes. The electrodes consist of a separated pair formed on an upper surface of the crystal wherein one of the pair is comb-shaped and the other of the pair is rectangular. In an alternative embodiment, the field is provided by a corona wire.
Harada et al. (U.S. Pat. No. 5,570,225) teaches the formation of domain reversals in a MgO—LiNbO3 or a MgO—LiTaO3 non-linear unipolarized ferroelectric crystal by first proton-exchanging an appropriate region, diffusing Ti through the region or diffusing Li through the region and then applying electrodes to a surface of the crystal and creating an electric field by applying a direct or pulsed current to the electrodes.
Harada et al. (U.S. Pat. No. 5,522,973) teaches the formation of domain reversals in a MgO—LiNbO3 or a MgO—LiTaO3 non-linear unipolarized ferroelectric crystal by first proton-exchanging an appropriate region and then applying patterned electrodes to a surface of the crystal and creating an electric field between the electrodes. The electrodes consist of a separated pair formed on an upper surface of the crystal wherein one of the pair is comb-shaped and the other of the pair is rectangular. In an alternative embodiment, the field is provided by a corona wire.
Harada et al. (U.S. Pat. No. 5,594,746) teach a method for forming domain reversals in a ferroelectric crystal using a corona wire and a pattern of electrodes formed on the crystal. There is also taught an apparatus for creating the domain reversals comprising the electrode, the corona wire, a power source and an evacuated chamber.
Byer et al. (U.S. Pat. No. 6,156,255) teach a method for forming patterned domain reversals in a non-linear ferroelectric material using an electric field applied by means of spaced conductors. There is also taught a method of first characterizing the material to determine the most efficient way to achieve the desired result. The characterization seeks to establish the proper application of surface treatments as well as the best geometry of the crystal.
The methods disclosed above produce some disadvantageous effects. In particular, Ti indiffusion, Li outdiffusion and proton exchange followed by heat treatment, produces undesirable changes in the index of refraction of the material. The use of corona discharge methods and the use of high temperature thermal cycles and vacuum processing increase fabrication complexity and expense. In addition, such processes can damage crystal surfaces and, thereby, adversely affect the refractive properties of the crystal. The disavantages of the various methods can be summarized as follows:
(1) Many of the methods cited above produce high temperatures which cause low throughput and process control difficulties. A ferroelectric material should be heated to the Curie temperature to reduce the magnitude of the external field required to create domain reversals in all methods except the E-field method (electric field between applied electrodes) and the corona discharge method. Thus, the average operating temperature is approximately 500° C., which can cause wafer breakdowns, lead to stresses in the heating and cooling cycles and also result in the diffusion of metals into the ferroelectric material.
(2) The necessity of high vacuum processing slows down the process cycle and reduces throughput. Domain reversal techniques based on electron discharge require high vacuum to prevent interference from the environment and arcing between discrete electrodes. A vacuum of the order of 10−7 Torr takes a long time to produce.
(3) The depth of the domain reversal is often too shallow to use a bulk device like a solid state laser chip. Most domain reversal processes use surface chemical reactions, such as Ti in-diffusion, Li2O out-diffusion or proton exchange to lower the Curie temperature. In these cases, the depth of domain inversion is on the order of several microns. It is, therefore, only suitable to use such domain-reversed crystals in conjunction with surface devices such as wave-guides or surface acoustic wave (SAW) devices. To use bulk devices as radiation sources would require a ferroelectric device with domain reversals to a depth of millimeters.
(4) The scanning rate of domain reversals is very slow in most methods. To obtain a high quality (sharply defined) domain reversal, requires the use of slow methods, such as electron-beam writing or corona discharge.
Based on the limitations described above, we conclude that the E-field method (electric field produced between electrodes deposited on the material) has more advantages than the other methods. The chief disadvantages of this method are seen when the domain reversals must have a short period (narrow width) of about 10 microns or less and the wafer thickness is about 0.5 mm in CLN. In this case, the domain walls do not retain a planarity between the upper and lower surface planes of the crystal (between the +z and the −z surfaces). Moreover, in thicker wafers, the domain wall planarity is even worse. To alleviate these problems, the present invention teaches a double-sided poling process for ferroelectric domain reversals which also includes a new alignment technique. The method facilitates well defined poling in large area wafers and yields uniform domain reversals with a good, controllable process duty cycle and high quality domain walls.

Domain reversal control method for ferroelectric materials


A package structure in which a coreless substrate has direct electrical connections to a semiconductor chip and a manufacturing method thereof are disclosed. The method includes the following steps: providing a metal carrier board having a cavity; placing a chip having a plurality of electrode pads on an active surface in the cavity of a board; filling the cavity with an adhesive for fixing the chip; forming a solder mask on the active surface of the chip and the surface of the metal carrier board at the same side, wherein the solder mask has a plurality of openings to expose the electrode pads of the chip; forming a built-up structure on the solder mask and the exposed active surface of the chip in the openings; and removing the metal carrier board. In this method the metal carrier board can support the built-up structure to thereby avoid warpage.

1. Field of the Invention
The present invention relates to a package structure and a manufacturing method thereof. In more detail, the present invention relates to a package structure and a manufacturing method thereof in which a coreless substrate with circuits has direct electrical connections to a semiconductor chip.
2. Description of Related Art
As the electronics industry develops rapidly, research moves towards electronic devices with multiple functions and high performance. Hence, circuit boards with many active and passive components and circuit connections integrated therein have advanced from being single-layered boards to multi-layered boards by an interlayer connection technique, so as to expand circuit layout space in a limited circuit board to thereby meet the demand of the application of high-density integrated circuits.
With regard to conventional semiconductor package structures, a chip is mounted on the top surface of a packaging substrate, and then electrically connected thereto by wire bonding. Alternatively, the chip is electrically connected with the top surface of the substrate by the flip chip technique. Then, electrical connections to a printed circuit board can be achieved by disposing solder balls on the back surface of the substrate. However, even though the purpose of high quantity pin counts can be achieved through the method illustrated above, the electrical performance of a device operated in higher frequency or at higher speed can be unavailable or limited due to the long paths of conductive circuits.
An advanced structure of a flip chip ball grid array (FCBGA) packaging substrate is shown in FIG. 1. In the manufacturing of the FCBGA package structure, a semiconductor chip 10, which has electrode pads 101 on an active surface used for signal input and output, is first provided. Solder bumps 11 are formed on the electrode pads 101 and electrically connect to the bump pads 121a disposed on a substrate 12 having a core layer 120. The substrate 12 here has a plurality of wiring layers 122 and insulation layers 123. In addition, two of wiring layers 122 are electrically connected to each other by conductive vias 125. Moreover, a solder mask 13a is formed on a top wiring layer 122a of the substrate 12 to protect the top wiring layer 122a and to expose the bump pads 121a. Furthermore, the core layer 120 has a plurality of plated through holes 124 conducting the wiring layers 122 on both the surfaces thereof. A bottom wiring layer 122b of the substrate 12 has a plurality of ball pads 121b. Besides, a solder mask 13b is formed on the bottom wiring layer 122b so as to protect the bottom wiring layer 122b and to expose the ball pads 121b. Solder balls 14 are formed on the ball pads 121b to offer electrical connections for a printed circuit board (not shown). Finally, a flip chip ball grid array packaging substrate is obtained.
Even though a flip chip ball grid array packaging substrate could meet the requirement of high quantity pin counts and be used in a device operated in high frequency, there are many limitations in this technique, especially regarding electrical connections. That is, the material used in electrical connections (e.g. solder materials containing Pb) may be prohibited for application due to environmental protection. Furthermore, other alternative materials still have electrical and mechanical problems, such as unstable quality of connections, and those problems are still awaiting solutions. Besides, a conventional flip-chip package structure is electrically connected to a semiconductor chip by solder bumps. During the process of manufacturing fine circuits, filling of a gap between the semiconductor chip and the packaging substrate with resin is required. However, resin is viscous and does not easily flow into the gap, thus the finer the circuits of a packaging substrate, the longer the time needed for filling with the resin. Additionally, there are many unfilled voids in the resin filled region, resulting in increased risk of bust-up of the package structure.
Otherwise, the aforementioned substrate 12 having the core layer 120 is formed by way of the following steps. First, circuit formation is performed on a dielectric layer, and then the core layer 120 is obtained. Manufacturing of a built-up structure is subsequently performed on the core layer 120 so that the substrate 12 has a plurality of circuit layers. Additionally, the core layer 120 has a plurality of plated through holes 124 (PTHs) formed therein. In general, the diameter of the plated through holes 124 is about 100 μm or more. The diameter of the conductive vias is about 50 μm. However, the formed plated through holes 124 compromise the flexibility of the fine circuit layout. Hence, reduction of conductive paths in the substrate 12 is limited, and the electrical characteristics could not be well improved. Furthermore, the thickness of the substrate 12 could not be decreased efficiently because of the existence of the core layer 120. On the other hand, if the core layer 120 is thinned to 60 μm or less, it is difficult to produce the substrate 12, and further results in great reduction in the yield of the substrate 12. Therefore, the core layer 120 does not favor reduction of the whole thickness of the package structure, thus the demands of compact and lightweight electronic devices have not been met.
In the manufacturing of the foregoing substrate with multiple circuit layers, the core layer needs to be prepared first. Subsequently, the dielectric layers and circuit layers stacked on the core layer are formed to obtain a multilayered substrate. These steps of the manufacturing are complex and not easily simplified.
Therefore, the issue of how to provide a circuit board structure, or a method for manufacturing the same to avoid limitations as the mentioned above, e.g. reduction of the substrate thickness, an increase of circuit layer density, good yield of products, and simplification of the manufacturing, is important in this field.

Package structure in which coreless substrate has direct electrical connections to semiconductor chip and manufacturing method thereof

Phoenix Precision Technology Corporation


Metal-metal surface contact systems in metalworking processes may be lubricated by applying thereto a composition comprising an ester, wherein the ester has a full film traction coefficient of less than about 0.05 at a pressure of about 0.5 to about 1.2 GPa, a temperature of about 50.degree. C. and a sliding velocity of about 0.5 to about 10 msec.sup.-1. The ester is represented by the general formula: ##STR1## where R.sup.1 and R.sup.2, R.sup.3 and R.sup.4 and m are set forth in the Summary of the Invention. The composition may be mixed with a solvent to form a solution or emulsified prior to application to the metallic surface.

As metalworking processes become more complex and sophisticated and operate at higher pressures and speeds, increased demands are placed on lubricants to withstand the severe forces generated by hostile environments of the metalworking processes. Typical metalworking processes involve elastic or plastic deformation or cold working of metals. Examples of such metalworking processes include cold rolling of steel or aluminum sheets or foils, stamping, drawing, ironing, cutting, grinding, broaching, drilling and machining of metallic materials. The metallic materials from which the metalworking apparatus and articles to be fabricated are made include steel, cast iron, and ferrous alloys, as well as aluminum alloys and other non-ferrous alloys including such components as titanium, magnesium, copper, tin and brass.
Desirable lubricants not only reduce the coefficient of sliding friction between contacting metallic surfaces, but, among other attributes, control the temperature of the metalworking components and article during the metalworking process.
Lubricants are generally any liquid or solid which when used alone or with other components of a composition reduce friction between metallic parts and facilitate metal removal. Lubricity is the ability of a lubricant material to effectively reduce friction and wear of two metallic surfaces in processes involving elastic or bulk plastic deformation of one or both of the metallic surfaces. Lubricity of a lubricant is reflected in the degree of smoothness of surface finish of a product of a metalworking process following deformation, as well as the ability to control the temperature of the metalworking components and article during deformation and strain distribution in the metal product formed during the metalworking process.
Presently, conventional synthetic ester lubricants, such as polyol esters, and other natural fats are used as lubricating fluids for metalworking operations. U.S. Pat. No. 3,526,596 discloses that polyol esters of fatty acids having twelve to twenty-two carbon atoms, preferably polyols having two to twelve hydroxy groups and glycols having two to forty carbon atoms, are useful as lubricants in metalworking operations.
U.S. Pat. No. 3,681,440 discloses lubricants of esters derived from aliphatic or aromatic monocarboxylic acids and dineoalkyl ethers having a tetrahydroxy functionality.
U.S. Pat. No. 4,178,261 discloses a base lubricating oil of a carboxylic acid ester formed by reacting 6-cyclohexylhexanoic acid, optionally in combination with an aliphatic monocarboxylic acid having 4 to 20 carbon atoms, with a polyhydric alcohol.
U.S. Pat. No. 4,871,476 discloses a synthetic lubricating fluid for power transmissions which comprises (a) an ester or its derivative of cyclohexanol and cyclohexanecarboxylic acid or its derivative; and (b) 1% to 70% by weight of a branched poly-.alpha.-olefin. The ester has a traction coefficient about 5% to 7% higher than those of commercially available traction-based oils having a viscosity in the same range.
U.S. Pat. No 4,786,427 discloses lubricants of ester compounds for use in traction drives. U.S. Pat. No. 4,978,468 also discloses a traction fluid, the fluid comprising (1) at least one ester compound or its derivative containing a cyclohexyl or alkyl substituted cyclohexyl group joined to a linear chain hydrocarbon group by an ester group; and (2) 0.1% to 95% by weight of at least one polymer selected from hydrocarbon polymers, such as polyolefins and hydrogenation polyolefins, and polyesters such as polyacrylates and polymethacrylates. The ester components exhibit high traction coefficients in excess of 0.075.
In metalworking operations, as opposed to traction drives, it is desirable to have a lubricant possessing low full film traction and sliding friction coefficients. Full film lubrication is defined herein to mean a condition of lubrication in which the film thickness of the lubricant is appreciably greater than that required to cover the surface asperities of the metallic surface when subjected to the operating load, so that the effect of the surface asperities is not noticeable. See Organization For Economic Cooperation and Development, Friction, Wear and Lubrication Glossary at page 61 (Paris, 1969). In regions where full film lubrication cannot be achieved, it is desirable that such a lubricant have a low full film traction coefficient under hydrodynamic lubricating conditions and a low friction coefficient under boundary lubricating conditions.
Lubricants for use in metalworking operations must be capable of withstanding the high shear forces, temperatures and pressures encountered in such operations and provide a film of sufficient thickness to protect contacting metallic surfaces. Such a lubricant should resist viscosity changes during the metalworking process and possess a shear yield stress lower than that of the metallic surfaces. Ductility and mobility under severe operating conditions and a high affinity for metallic surfaces for inhibiting metal-to-metal contact between the surfaces is also desirable.
It is desirable for a metalworking lubricant to have not only high pressure rheological and low traction properties but also to exhibit hydrolytic stability. Typical known synthetic esters, primarily of the neopentyl type, suffer from hydrolytic instability. High stability to oxidative or hydrolytic breakdown is particularly important, because thermal or hydrolytic decomposition can result in the lubricant itself becoming corrosive and/or volatile, as well as generally less effective. Also, as the lubricant degrades, sludge and other decomposition products may deposit or form on the surfaces of the metallic components and articles and adversely affect the metalworking process.
Other drawbacks of lubricants suffering from thermal and hydrolytic instability include discoloration of the work product and degradation in the quality of the work product due to inconsistencies in the machining process because of viscosity changes or coating ability of the lubricant. Thus, it is desirable to have a lubricant which possesses not only a low coefficient of sliding friction, but also one which is hydrolytically stable to counteract water added to emulsify the lubricant composition and water used to cool the metal surfaces during the metalworking processes.

Method for lubricating metal-metal contact systems in metalworking operations with cyclohexyl esters


The apparatus is a child's stroller that maintains all the wheels on the ground while it is being folded. The rear legs are interconnected with but separated from the armrests and move on circular paths, the centers of which are pivot points on the armrests. Therefore, the tops of the rear legs move around to a height different from the position of the front leg pivot point, and the location of the tops of the rear legs are determined by the position of the attached wheels rather by the pivot point of the front legs. Another linkage lowers the canopy support frame as the stroller is being folded in order to reduce the stroller's overall folded length.

This invention deals generally with children's strollers and more specifically with a stroller that folds compactly and is very stable when folded and standing upright.
Currently many strollers stand when they are in a folded position, but many are unstable or awkward to fold. Some require the user to fold the stroller to the ground and then bend over and pick it up to place it in a vertical orientation to make it stand. This is inconvenient due to the fact that the user must bend over and pick up the weight of the stroller. Still others require the stroller to stand on the rear wheels and some other frame component, usually the basket tube, and during the folding process the stroller must be controlled with two hands in order to keep it balanced over the rear wheels. In many cases the footprint of the standing stroller is so small that it makes the stroller somewhat unstable and easy to knock over.
It is always desirable to have the stroller fold to the smallest folded size possible so that it does not take up extra space when stored and to make it more convenient to put in and take out of vehicles. Typically, the handle and the canopy frame are the areas that contribute most to the overall folded size in the longest dimension. In such configurations the handle controls the overall folded size, but the canopy frame is the second largest component. It is common to have the stroller handle adjustable in height to accommodate users of different heights. It is also common for there to be a folding mechanism that allows the handle and the upper part of handle tube to rotate in a range of approximately 180 degrees so that the handle can be placed in a storage position thereby reducing the overall size of the folded stroller. This typically leaves the canopy frame as the highest point of the folded stroller which leaves it vulnerable to damage, and is the major factor in the overall folded size.
Many strollers also have a storage area above the canopy and below the handle for use by the person pushing the stroller. Typically, this storage area is a molded rigid tray that includes a cup holder and storage compartments with or without lids. The problem with such storage areas is that they are a pre-designed and unchangeable structure. Nothing is available to serve as simple a purpose as moving the cup holder to a location convenient for a left handed person.
It would be very beneficial to have a stroller that not only keeps the front and rear wheels on the ground while being folded, but is also very stable when standing, has a shorter folded height than is presently available, and includes a storage area just below the handle that can be rearranged for the user's convenience.


A method and apparatus for detecting spectral null sequences of a spectrally-constrained code on a noisy communications channel. From a Viterbi detector with a trellis structure comprising a plurality of states and edges, predetermined ones of the states and edges in the trellis structure are deleted at preselected times modulo N, such as times .phi. modulo N and/or at intermediate times m modulo N, where m=.phi., thereby to create a time-varying trellis structure for limiting the maximum length of dominant error events. The deleted edges are generally those edges which would have entered or emanated from the deleted states if they were not deleted. The trellis structure may be a so-called systolic structure, in which case the spectral null sequences are preferably DC-free or Nyquist free.

The following references are considered to be the prior art most pertinent to the present invention:
[A] R. W. Wood, "Viterbi reception of Miller-squared code on a tape channel," Proc. 4th Int. Conf. Video and Data Recording, IERE Conf. Proc. 54, Southampton, England, Apr. 1982, pp. 333-343. PA1 [B] R. Karabed and P. H. Siegel, "Matched spectral null trellis codes for partial response channels," U.S. Pat. No. 4,888,779, Dec. 19, 1989. PA1 [C] R. Karabed and P. H. Siegel, "Matched spectral null codes for partial response channels," IEEE Trans. Info. Th , vol. 37, no. 3, pp. 818-855, May 1991. PA1 [D] J. Rae and L. J. Fredrickson, "Systolic architecture for Viterbi detection of DC-free sequences," U.S. Ser. No. 07/776,142, filed Oct. 15, 1991. PA1 [E] R. Karabed and P. H. Siegel, "Phase-invariant rate 8/10 matched spectral null code for PRML," allowed U.S. Ser. No. 07/747,401, filed Aug. 14, 1991, which is a continuation of U.S. Ser. No 07/434,970, filed Nov. 13, 1989 now abandoned. PA1 [F] E. Eleftheriou and R. Cideciyan, "Quaternary codes for partial-response channels," Proc. 1990 IEEE Global Telecomm. Conf., San Diego, Calif., Dec. 1990, pp. 1673-1678. PA1 (1) Spectral null sequences (such as DC-free or Nyquist-free sequences) are represented by diagrams that reflect a bound on the accumulated charge or the running digital sums (see Reference [A]). These sequences are typically generated by a finite state machine, such as disclosed in Reference [B]. PA1 (2) Spectral null sequences can also be generated at the output of a sampled partial-response channel (typically represented as a digital filter) where the channel frequency response has a null at a particular frequency, such as also disclosed in Reference [B]. PA1 (3) The two approaches can be combined, as has been done in the context of matched-spectral-null coding for partial-response channels (see References [B] and [C]).
Many communications applications utilize spectrally-constrained codes to generate spectral null sequences. The term spectral null sequences, as herein used, refers generically to codes having sequences With no spectral power or constant spectral power (i.e. a spectral density null with discrete spectral line) at certain frequencies, such as zero frequency (referred to as DC-free codes) or Nyquist frequency (referred to as Nyquist-free codes). Depending upon the application, these spectral null sequences can use symbols taken from any finite alphabet that is a subset of the complex numbers. The most common examples are integer-valued sequences with binary alphabet {0,1}, bipolar alphabet {+1,-1}, or quaternary alphabet {.+-.1,+3}.
Spectral null sequences can arise in the following ways, each relevant to this invention:
Spectral null sequences have been shown to have certain inherent distance properties that can improve the reliability of their recovery from data samples generated at the output of noisy communications channels. It has also been demonstrated that, at moderate-to-high signal-to-noise ratios, performance equivalent to that of a maximum-likelihood detector can be achieved by applying the algorithm executed by a Viterbi detector to a reduced-complexity trellis that tracks only the spectral content of sequences, as described in References [A], [B], and [C].
The likelihood of Viterbi detector error events decreases as a function of the sum of the squared errors, referred to as the "error distance." At moderate signal-to-noise ratios, the minimum (and next-minimum) distance error events are the most dominant. The existence of very long error events detracts from the system performance and implementation in several ways. Even with long path memory, the average error rate is degraded by survivor sequence truncation and larger error burst lengths.
The maximum length of such error events is determined by the parallel paths in the trellis that do not accumulate distance (referred to as "quasicatastrophic sequences"). In the context of trellis structures describing spectral null constraints, these sequences can be arbitrarily long. One solution to this problem was presented in References [B] and [C]; namely, the use of coding to impose constraints on the channel output sequences in order to prevent the occurrence of quasicatastrophic trellis sequences. This approach, although adequate in some instances, has two potential drawbacks in certain data storage applications. First, particularly for high-rate codes, the encoder and decoder functions may entail additional complexity. Second, the maximum length of dominant error events, although guaranteed to be bounded above by a fixed, finite number, may still be too long for a particular application.
To illustrate these two points, reference is made to the rate 8/10 DC-free code, described in Reference [B]. That code was designed for use as a matched-spectral-null (MSN) code for a dicode (1-D) partial-response channel. Viewed as a code for a full response channel (i.e., a memoryless channel), the code doubles the minimum Hamming distance relative to the uncoded channel, providing a minimum Hamming distance of 2 instead of 1. The detector trellis for such an application is shown in FIG. 1. When the code is viewed as a MSN code and applied to a dicode partial-response channel, the detector uses the six-state trellis depicted in FIG. 2.
As noted in Reference [B], the high-rate 8/10 DC-free code does not avoid all quasicatastrophic sequences in the trellis structures. One approach to alleviating this problem was described in Reference [E], where a rate 8/10 DC-free code with acceptable complexity was designed to avoid quasicatastrophic sequences. The maximum length of minimum distance error events in that system could be as much as 42 bits. Next-minimum distance error events had a maximum length in excess of 70 bits. Further improvements from coding alone are either impossible or tend to drive the encoder/decoder hardware complexity to unacceptable levels.

Time-varying Viterbi detector for control of error event length

International Business Machines Corporation


Novel photocurable, adherent coating compositions and a method for preparing such compositions are described. A substrate can be coated with a first compound bearing a plurality of onium groups and a second compound bearing a plurality of nucleophilic groups. The resulting coating cures readily upon exposure to actinic radiation. These compositions can be used in preparation of photoresists, composite membranes, and modifying surfaces either for accepting adhesives or releasing oily soil.

The present invention relates to a photocurable composition, which is suitable for making photoresists, composite permselective membranes, and novel coatings.
A wide variety of photocurable compositions and photo-reactive materials are known in the prior art. Two main approaches exist in the art for producing photocurable compositions: (1) photocurable (photoinduced radical) compositions based upon polymerizable ethylenically unsaturated groups, and (2) photocurable compositions based upon photoacid generating compounds which function as photoinitiators for cationic polymerization. Both these approaches are reviewed in UV Curing; Science and Technology, S. P. Pappas, Editor, Technology Marketing Corporation, Norwalk, Conn. (1980). Illustrative ethylenically unsaturated compositions are described in U.S. Pat. Nos. 4,544,621; 4,564,580, 4,668,601, and 4,798,877. In one embodiment these photocurable compositions can comprise a photoinitiator, such as the onium compounds described in U.S. Pat. No. 4,632,891, and a polymerizable material which is activated by the photoinitiator. U.S. Pat. No. 4,229,519 discloses that polymers containing quaternary nitrogen groups bearing ethylenically unsaturated groups may be cured with radiation under nitrogen in the presence of a suitable photoinitiator.
Illustrative of photocurable compositions which comprise a photoacid generating initiator are those described in U.S. Pat. Nos. 4,081,276; 4,551,418 and 4,610,952. The most common photoacid generating systems are diaryliodonium and triarylsulfonium salts. Recent work in photoacid generating compounds are described in proceedings of ACS Division of Polymeric Materials, Science and Engineering, Vol. 61, Fall Meeting 1989, in Miami Beach, Fla. J. V. Crivello, "Chemistry of Photoacid Generating Compound", p. 62. Generally, those photocurable compositions are water incompatible and require organic solvents for preparation of coatings.
U.S. Pat. No. 4,118,297 describes aromatic cyclic sulfonium zwitterions which polymerize upon exposure to ultraviolet light. Japanese Kokai No. 34,445, published Feb. 28, 1983 describes photosensitive zwitterions of aryl cyclic sulfonium.
In conventional processes a photocurable composition is selectively exposed to actinic or other radiation in a desired pattern. The portions of the composition which are not subjected to radiation can be removed or developed by immersion in a suitable solvent. This is commonly referred to as a negative photoresist. In some applications, a photocurable composition is rendered more soluble by exposure to radiation and this photoreacted area is removed during developing. Such compositions are referred to as positive photoresists.
Photocurable compositions are commonly used to form lithographic printing plates, inks cured with ultraviolet (UV) radiation or printed circuits. After development of the image on the desired substrate, the exposed surface may be etched by conventional techniques. Similar techniques can be used to manufacture integrated circuits and other microelectronic components. However, photoresists used in such applications must afford a very high degree of resolution because of the fine detail required in these miniaturized images.
For accurate image formation in microlithographic applications it is desirable to have a relatively thin coating (typically about 0.4 to 1.2 micrometers) of the photo-sensitive composition material. Further, it is desirable that the composition photocure relatively rapidly. The need for thin coatings of a photo-sensitive composition is related to the limited depth of focus of typical exposure patterning equipment and to the minimization of light scatter from the film deposited. The diffusing and spreading effect of the diffraction pattern of the exposing actinic radiation can limit the resolution of fine detail of the photoresist pattern. The very short wavelength of the exposing wavelength of this resist will (proportionately) decrease the width of the diffraction pattern and increase the resolution of fine detail of the resist pattern. In addition, the coating on the surface should be substantially free from pinholes and other blemishes, which would result in defects in the image produced.
Another field in which coatings having very few defects or irregularities are desired is in the field of permselective composite membranes. These are composite membranes which are used for selective separation of components in gases or liquids. Illustrative reverse osmosis membranes are described in U.S. Pat. No. 4,277,344. U.S. Pat. No. 4,704,324 describes preparation of membranes by reaction of onium compounds with nucleophilic compounds and is incorporated herein by reference.
New and improved photocurable coatings suitable for photoresist or membrane applications are desirable. Coatings which cure rapidly with few defects using deep UV radiation and which can be applied from an aqueous solution would be advantageous. These coatings can be used with conventional etchings for manufacture of electronic components and also in membrane applications where chemical stability is of particular importance.
Adhesives are used to bond together organic polymeric components in automobiles and electronic devices. To attain the desired adhesion, polymer surfaces often need to be modified by methods such as chemical etching, electron bombardment and corona discharge. These methods often utilize treatment with chemicals, which may present environmental hazards, produce toxic gases and are inconvenient and expensive. A new and improved method of modifying polymer surface is desired.
Fluorocarbon polymers are used in applications that require anti-soiling and oily soil release such as fabrics and cooking utensils. There is a need for a means of applying a photocured or crosslinked fluorocarbon coating to surfaces.


Interferometric transform spectrometer (ITS) systems and methods of operation thereof. In one example, an ITS system includes a Michelson interferometer that introduces a varying optical path length difference (OPD) between its two arms so as to produce an interferogram, a detector that receives and samples the interferogram, and a scan controller coupled to the detector and to Michelson interferometer. The scan controller controls the Michelson interferometer to vary the OPD in discrete steps such that the detector provides M samples of the interferogram for each of two scan segments. In the first scan segment, the M samples have a uniform or non-uniform sample spacing and the OPD has a first maximum value. In the second scan segment, the M samples have an incrementally increasing sample spacing and the OPD has a second maximum value that is at least twice the first maximum value.

Imaging spectroscopy is widely used in remote sensing applications. One type of interferometric spectrometer used to supply spectral data for many remote sensing applications is called a Fourier Transform Spectrometer (FTS). A common form of an FTS employs a Michelson interferometer with one arm having a variable optical path length. The variable optical path length may be implemented using a movable minor. By scanning the movable mirror over some distance, an interference pattern or interferogram is produced at the imaging sensor (e.g., a focal plane array) that encodes the spectrum of the source (the amplitude of each incident spectral wavelength, or frequency, or wavenumber, is encoded as the amplitude of a cosine signal of given frequency). An FTS with a maximum optical path length difference (OPD) between the two arms of L centimeters (cm) provides a spectral resolution of 1/(2L) cm−1. The FTS uses the Discrete Fourier Transform (DFT) or its faster algorithm, the Fast Fourier Transform (FFT), to convert the auto-correlation to physical spectra. The encoded spectrum is the Fourier transform of the source. The FFT is efficient when large sample sets must be processed, but produces artifacts if the variable arm is not precisely controlled to provide uniformly spaced samples. The FTS also requires that the entire spectrum be computed at once, despite the fact that most spectral targets can be detected using only a few spectral samples or subsets of the spectrum. The DFT and FFT have limited spectral range due to aliasing effects, and once the band center is set in one part of the spectrum it cannot be modified elsewhere without recomputing the entire transform.
Commonly-owned U.S. Pat. No. 8,203,715 titled "KNOWLEDGE BASED SPECTROMETER," which is herein incorporated by reference in its entirety, discloses an alternate configuration of an interferometric transform spectrometer that does not rely on DFT/FFT-based processing, and therefore can accommodate non-uniformly spaced samples. More specifically, U.S. Pat. No. 8,203,715 discloses a system in which the variable optical path length in one arm of the interferometer may introduce a maximum OPD of L (similar to the conventional FTS), but where knowledge of the "uncontrolled" sample step size and an alternative algorithm to the DFT/FFT is used to process the collected data.

Imaging spectrometer with extended resolution