The techniques introduced here provide for efficient management of storage resources in a modern, dynamic data center through the use of virtual storage appliances. Virtual storage appliances perform storage operations and execute in or as a virtual machine on a hypervisor. A storage management system monitors a storage system to determine whether the storage system is satisfying a service level objective for an application. The storage management system then manages (e.g., instantiates, shuts down, or reconfigures) a virtual storage appliance on a physical server. The virtual storage appliance uses resources of the physical server to meet the storage related needs of the application that the storage system cannot provide. This automatic and dynamic management of virtual storage appliances by the storage management system allows storage systems to quickly react to changing storage needs of applications without requiring expensive excess storage capacity.

A modern data center can include a large number of storage systems, including storage controllers and mass storage devices, and physical servers for hosting applications which access the storage systems. Today's data centers, especially in cloud computing environments, typically have large, multi-tenant systems, i.e., multiple organizations and/or applications share the same underlying processing and storage hardware. The physical servers that host the applications in such environments often include hypervisors, with the individual applications and their operating systems running as virtual machines (VMs) logically on top of the hypervisors.
These data centers are often extremely dynamic in their makeup and usage. For example, the set of applications running on the physical servers in the data center often changes due to the multi-tenant nature of the data center. This dynamism typically results in a fluctuating storage workload for the data center. Further, the storage workload for the data center often changes over time regardless of whether the set of applications changes, e.g., the data center has a peak storage workload during a specific time of day. The difference between an average and peak load can be substantial. Further, in order to balance utilization of processing and storage resources (or for other management reasons), applications may be migrated between physical servers and sometimes between data centers, adding to the dynamic nature of the data center.
Conventional storage management systems are not capable of efficiently handling the dynamic nature of today's data centers. Typically, conventional storage management systems rely on the availability of pre-allocated resources, e.g., processors, memory, flash storage, disk drives, network, etc., often in the form of entire storage systems, to handle the storage needs of an application. If the allocated resources do not meet the storage demand for the data center, typically additional hardware resources are installed to meet the demand. Installing additional hardware resources can be time consuming, labor intensive, and expensive. In some cases, entire storage systems are purchased and installed in the data center to compensate for a peak load that is slightly over the capacity of the previously allocated resources. As a result, conventional storage management techniques result in either an abundance of physical resources that are not efficiently being used (i.e., excess capacity) or, when demand exceeds capacity, cannot react quickly enough to reasonably satisfy the demand.

Dynamic storage management using virtual storage appliances


In a dual direction horizontal bi-directional scan circuit, deterioration of the picture quality is prevented, while linearity is improved without supplying wasteful deflecting current, and pin distortion is corrected. The deflecting current in the going scan and in the returning scan are supplied to each deflecting coil by first and second resonance circuits, and capacitors substantially the same in capacitance are provided in the first and second resonance circuits to bias the deflecting voltage so that the terminal voltage and the power source voltage of the capacitors are synchronized to the vertical synchronizing signals to produce a parabolic modulation.

FIELD OF THE INVENTION
The present invention relates to a bi-directional scan circuit, and more particularly is suitable to apply for a horizontal bi-directional scan circuit of a dual direction deflection circuit.
Heretofore such type of a deflection circuit, (hereinafter, referred to as "a deflection circuit of a bi-directional scan circuit") has been proposed in U.S. Pat. No. 4,672,449, in which a horizontal deflection coil is driven by using drive signals such as sine-wave signals, the signal level of which changes symmetrically before and after the predetermined point of time.
With the deflection circuit, a display image can be formed by means of either a scan running from left to right in a display (hereinafter, referred to as "going scan") or a scan running inversely from right to left in the display (hereinafter, referred to as "returning scan"), so that the deflecting frequency can be reduced to 1/2.
In this deflection circuit, there can be prevented a sudden change of the deflecting current which generates saw-tooth signals, so as to reduce unnecessary radiation etc. and leads of elements of the deflection circuit.
Especially if the deflection circuit is composed of a resonance circuit and the deflection coil is driven by a sine-wave current as shown in FIGS. 1A and 1B, the electric power for required deflecting can be reduced by a simple constitution as discussed in U.S. Pat. No. 5,051,668.
However, when the deflection coil is driven by a pure sine-wave current, linearity of the deflecting current I.sub.L deteriorates during the peak period thereof shown by slant lines in FIGS. 1A and 1B. Above all, this drives the deflection coil to overscan, therefore there is a problem of supplying wasteful deflecting current I.sub.L during the period of the slant lines.
In practice, when a conventional 34-inch cathode-ray tube is used, the period of the slant lines corresponds to approximately 38 [%] of the whole period, and the deflecting current I.sub.L corresponding to approximately 17 [%] in amplitude is supplied wastefully.
As one method for solving this problem, the time base of the video signal is controlled so that there is a method for improving the linearity without supplying wasteful deflecting current I.sub.L.
However, this method complicates the constitution of the video signal processing circuit and the beam current needs to be changed in accordance with the control of time base for keeping the brightness of the whole display constant. Thus, this makes the whole constitution complicated.
Besides, there is a problem of the change of beam shape etc., by the change of the beam current.
On the other hand, as shown in FIGS. 2A and 2B, there is a method in which the deflecting current I.sub.L is applied in order to delete the wasteful portion.
In this method, where the deflection coil is driven in accordance with the operating principle shown in FIG. 3, the deflection coil L can be driven by such deflecting current I.sub.L.
In the deflection circuit 1 of FIG. 3, a capacitor C1 is connected to the deflection coil L via a selecting circuit 2, so that the resonance circuit is composed of the capacitor C1 and the deflection coil L.
If left alone in this state, in the deflection coil L, the deflecting current of a sine-wave shape flows. If this resonance circuit has no loss, the deflecting current continuously flows with no attenuation.
With respect to the deflecting current I.sub.L changing in the above manner, when the terminal voltage of the deflection coil L falls to the predetermined voltage V.sub.M at the point of time t1, the contact of the selecting circuit 2 of the deflection circuit 1 is switched to the capacitor C2 side.
Here, if the capacitance of capacitors C1 and C2 is equal, and the capacitor C2 is charged to a voltage -V.sub.M, the deflecting voltage V.sub.L drastically falls to the voltage -V.sub.M from the voltage V.sub.M at the point of time t1, and changes in a sine-wave shape from this voltage -V.sub.M thereafter.
With respect to the deflecting voltage V.sub.L changing in a sine-wave shape, when the deflecting voltage V.sub.L continuously rises to the voltage -V.sub.M at the point of time t2, the contact of the selecting circuit 2 of the deflection circuit 1 is switched.
Thus, the deflection coil L is connected to the capacitor C1 which is separated from the capacitor C2 and is kept to the voltage V.sub.M. The deflecting voltage V.sub.L rises to V.sub.M from the voltage -V.sub.M, and changes in a sine-wave shape thereafter.
By this operation, two capacitors C1 and C2 are alternately switched at the predetermined timing and are connected to the deflecting coil L, and the voltage V.sub.M and -V.sub.M on switching are set to a predetermined value, so that the linearity can be improved without supplying wasteful deflecting current.
As a matter of fact, this type of deflecting current I.sub.L can be formed by the deflection circuit 4 as shown by an equivalent circuit in FIG. 4.
That is, the deflection circuit 4 is composed of the resonance circuit with the capacitor C and the deflecting coil L connected to each other via the selecting circuit 6.
In the deflection circuit 4, the contact of this switching circuit 6 is switched to insert the direct-current power source 8 of a voltage 2V.sub.M into the resonance circuit during the period that the deflecting voltage V.sub.L rises above the voltage -V.sub.M the period being from the point of time t2 to t1 in FIGS. 2A and 2B.
Thus, during the period from the point of time t2 to t1, the direct-current level of the deflecting voltage V.sub.L is shifted by the voltage 2V.sub.M and the deflecting coil L can be driven with the deflecting voltage V.sub.L shown in FIGS. 2A and 2B.
Concretely, as shown in FIG. 5, the selecting circuit 6 (FIG. 4) is provided with a semiconductor switch corresponding to resonance part 10 having the capacitor C and the deflecting coil L, so that an energy supplying part 12 is connected to supplement for the loss of the resonance part 10.
That is, the deflection circuit 14 connects the series circuit of the field-effect transistors Q3 and Q4 in parallel with the DC power source VB. The voltage V.sub.a, the driving power, is supplied from a connection node between the field-effect transistors Q3 and Q4 via the capacitor C3 and the coil L1.
In the deflection circuit 14, as shown in FIGS. 6A to 6M, the field-effect transistors Q3 and Q4 alternately are switched in on or off state. By this operation, the voltage V.sub.a of the connection node between the field-effect transistors Q3 and Q4 rises (FIG. 6C) at the cycle synchronizing with the deflecting voltage V.sub.L and the deflecting current I.sub.L (FIGS. 6A and 6B) of the deflecting coil L and then the driving power is supplied.
Further, in the deflection circuit 14, the series circuit of the field-effect transistors Q1 and Q2 is connected in parallel with the AC power source 8, and then the diodes D1 and D2 are connected in parallel with these field-effect transistors Q1 and Q2 respectively.
Furthermore, the capacitor C of the resonance part 10 is connected to the node between these field-effect transistors Q1 and Q2 of the selecting circuit 6 which is composed of the field-effect transistors Q1 and Q2, and the diodes D1 and D2.
In this construction, the deflection circuit 14 keeps the field-effect transistor Q2 connected to the ground in the on state so that the series resonance circuit of the deflecting coil L and the capacitor C is formed and the resonance current flows to the deflecting coil L. On the contrary, the field-effect transistor Q2 connected to the DC power source 8 is kept in the on state so that the power of the DC power source 8 can be supplied to the series resonance circuit of the deflecting coil L and the capacitor C.
By switching the connection of the selecting circuit 6 at the point of time t1 and t2, in the deflection circuit 14, the deflecting coil L can be driven with the condition as described above with FIG. 4.
In the deflection circuit 14, the timing at which the field-effect transistors Q1 and Q2 are switched to the off state is controlled to switch the connection of the entire selecting circuit 6.
That is, when the deflecting voltage V.sub.L arises to the voltage -V.sub.M at the point of time t2, the field-effect transistor Q2 is switched to the off state (FIG. 6G).
Hence, in the deflection circuit 14, the voltage Vb of the node between the field-effect transistors Q1 and Q2 (FIG. 6H) rapidly rises with the deflecting current I.sub.L, and the diode D1 changes immediately to the on state (FIG. 6D), and then the connection of the switching circuit 6 can be changed to the DC power source 8 side from the ground side.
When the field-effect transistor Q1 is switched on thereafter, the deflecting voltage V.sub.L rises to the voltage V.sub.M at the point of time t1, so that the field-effect transistor Q1 is switched to the off state (FIG. 6E).
Thus, the voltage Vb of the node of the field-effect transistors Q1 and Q2 rapidly rises with the deflecting current I.sub.L, and the diode D2 is immediately switched on (FIG. 6F) to switch the connection of the switching circuit 6 from the power source 8 side to the ground side.
Thus it can be recognized that the power supplied from the DC power source 8 to the deflection circuit 14 is only a little.
When the diode D1 switches on, the current flows out of the DC power source 8 therethrough. On the contrary, when the field-effect transistor Q1 switches on and the voltage Vb of the connection node starts to drop, the current flows in the direct-current power source 8 through this field-effect transistor Q1.
If the value of this current is different in charging and in discharging the deflecting current I.sub.L on the going scan and on the returning scan becomes different; so that the display picture becomes unsightly.
For this reason, as shown in FIG. 7 with the accompanying circuit, even if the DC power source 8 is replaced with a capacitor CS, the deflecting coil L will be driven by the deflecting current I.sub.L as described in FIG. 2.
Here, in the deflection circuit 20, the deflecting voltage V.sub.L is detected in the voltage detecting circuit 22, and based on the detected result, the field-effect transistors Q3 and Q4 are driven by means of the driving circuit 24.
Further, the detected result of the voltage detecting circuit 22 is outputted to an AFC circuit 26, and then the field-effect transistors Q1 and Q2 are driven by the driving circuit 28 on the basis of the result of the comparison of the horizontal synchronizing signal SYNC with the voltage detecting result, so that the whole operation of the deflection circuit 20 is synchronized with the horizontal synchronizing signal SYNC.
Furthermore, a pin-distortion correcting circuit 29 is connected to the capacitor CS to change the terminal voltage of the capacitor CS in synchronizing with the vertical synchronizing signal in a parabolic shape. Thus, the pin-distortion is corrected.
In this way, in accordance with the constitution shown in FIG. 7, the linearity of the image can be improved without supplying wasteful deflecting current; moreover, with the replacement of the DC power source 8 with the capacitor CS, the general construction can be simplified.
In this construction, however, there is the problem that the deflecting current I.sub.L slightly changes between the going scan and the returning scan, therefore the picture quality of the display is deteriorated corresponding to the changes of deflecting current.
That is, as shown in FIG. 8, the deflection circuit 20 can be represented, as an equivalent circuit, by replacing the field-effect transistor Q1 and the diode D1 with the switching circuit 30 and by replacing the field-effect transistor Q2 and the diode D2 with the switching circuit 32.
As shown in this equivalent circuit, in the deflection circuit 20, when the switching circuit 30 is switched on, the capacitor CS forms a part of the resonance circuit. On the contrary, when the switching circuit 32 is switched on, the capacitor CS is disconnected from the resonance circuit.
Hence, in the deflection circuit 20, the resonance frequencies in the going scan and in the returning scan differ from each other to present various changes in deflecting current between in the going scan and in the returning scan.
In this case, as shown in FIG. 11, the displayed positions of picture portions in the going scan and the returning scan differ from each other, and this results in a problem that the display becomes unseemly.
As a method to solve this problem, it is possible to increase the capacitance of this capacitor CS, however, if the capacitance of this capacitor CS is increased, the correction of the pin-distortion becomes difficult and this is not practical.


A camera is disclosed which provides for symbol imprinting on film using a second aperture through which light passes thereby exposing the symbols on the film.

1. Field of the Invention
The present invention generally relates to a camera having a symbol imprinting means. The device herein disclosed allows a camera user to imprint symbolic information on the film when a picture is taken. Specifically, the present invention discloses a mechanism which imprints symbolic information on film by using either the natural light or the light from the flash attachment on a camera for exposure onto the film. By providing such a mechanism, cameras may be provided with a data imprinting facility in a compact size with heretofore unrealized simplicity and economy.
2. Description of the Prior Art
Cameras using natural light for exposing data on the photosensitive surface of film are known. For example, U.S. Pat. Nos. 813,808; 1,192,058; 1,224,588; 1,249,612; 2,226,364; and 3,478,657 all generally relate to this feature. However, all of these cameras utilize complicated mechanisms, having a multitude of parts with the concomitant difficulty of assemblage and cost. Further, cameras which follow the teachings of these disclosures have a variety of operational inconveniences. None of these devices disclose a manner by which a device can use natural light for exposing data on film or which can utilize the light from a camera flash when such is necessary.
There is therefore a great need in the art for a device which can imprint data onto film which uses either natural light or a camera flash and which is also simple, compact, and economical manufacture and sell.


An electronic device may have a display with a brightness that is adjusted based on data gathered from one or more ambient light sensors (ALSs). In one suitable arrangement, an ALS may include a photodiode, a temperature sensor, a scaler, an analog-to-digital converter (ADC), and a subtractor. The subtractor may have a first input coupled to the photodiode via the ADC, a second input coupled to the temperature sensor via the scaler, and an output on which a leakage-compensated sensor output is provided. In another suitable arrangement, the ALS may include first and second photodiodes, a light blocking layer formed over the second photodiode, a scaler, and a subtractor. The subtractor may have a first input coupled to the first photodiode, a second input coupled to the second photodiode via the scaler, and an output on which a leakage-compensated sensor output is provided.

This relates to sensors and, more particularly, to ambient light sensors for electronic devices.
Cellular telephones and other portable devices with displays such a tablet computers sometimes contain ambient light sensors. An ambient light sensor can detect when a portable device is in a bright light environment. For example, an ambient light sensor can detect when a portable device is exposed to direct sunlight. When bright light is detected, the portable device can automatically increase the brightness level of the display to ensure that images on the display remain visible and are not obscured by the presence of the bright light. In dark surroundings, the display brightness level can be reduced to save power and provide a comfortable reading environment.
The fundamental limitation to ambient light sensor sensitivity is photo sensor leakage current (or "dark" current). With conventional devices, ambient light sensors can be implemented using first and second silicon photosensors (i.e., two photodiodes). The first photodiode is exposed to ambient light, whereas the second photodiode is a metal-covered photodiode that does not receive any ambient light. The first photodiode is used to measure a total current while the second photodiode is used to measure a leakage current. The leakage current is subtracted from the total current to compute a final leakage-current-compensated output value.
Computing leakage-current-compensated light levels in this way, however, is costly. In this conventional approach, the first and second photodiodes are of the same size (i.e., each of the first and second photodiodes take up the same amount of area on an integrated circuit substrate). A single photodiode can be at least 100,000 times larger than a single transistor (as an example). The use of two photosensors of the same size therefore takes up a significant amount of die area.
It would therefore be desirable to be able to provide ambient light sensors with reduced area requirements for electronic devices.

Ambient light sensors with photodiode leakage current compensation


The present disclosure is directed to processes for the direct conversion of lipidic biomass fuelstock to combustible fuels. In particular, the disclosure provides a process for the direct conversion of animal fats to transportations fuels suitable as replacement for petroleum-derived transportation fuels. In an example, the method comprises the steps of hydrolyzing a lipidic biomass to form free fatty acids, catalytically deoxygenating the free fatty acids to form n-alkanes, and reforming at least a portion of the n-alkanes into a mixture of compounds in the correct chain length, conformations, and ratio to be useful transportation fuels. Particularly, the product prepared comprises mixtures of hydrocarbon compounds selected from the group consisting of n-alkanes, isoalkanes, aromatics, cycloalkanes, and combinations thereof.

Fossil fuels (or petroleum-based fuels) have formed the basis for energy production and transportation in the 20th and 21st centuries. Increased need among growing populations and emerging nations, as well as market volatilities arising from wars, politics, and natural disasters, have focused world-wide attention on this non-renewable resource. In particular, rising costs and threats of shortages and supply interruptions have recently highlighted the need for alternative fuel sources to petroleum-based products. Biofuels have particularly been a focus for alternative fuels.
Bio-fuel is generally regarded as being any fuel derived from biomass. The term biomass is often used in regard to plant-based sources, such as corn, soy beans, flaxseed, rapeseed, sugar cane, and palm oil, but the term can generally extend to any recently living organisms, or their metabolic byproducts, that play a part in the carbon cycle.
The production of biofuels to replace fossil fuels is in active development, focusing on the use of cheap organic matter (usually cellulose, agricultural waste, and sewage waste) in the efficient production of liquid and gas biofuels which yield high net energy gain. Biofuels are viewed as environmentally favorable (particularly over fossil fuels) because the carbon in biofuels was recently extracted from atmospheric carbon dioxide by growing plants, and burning the biofuels does not result in a net increase of carbon dioxide in the Earth's atmosphere. Perhaps more importantly, biofuels are a renewable fuel source, and the potentially limitless fuel supply derived therefrom can have a stabilizing effect on fuel prices in the long-term.
One widespread use of biofuels is in home cooking and heating (e.g., wood, charcoal, and dried dung). Biologically produced alcohols, most commonly methanol and ethanol, and to a lesser extent propanol and butanol, can be produced through enzymatic and microbiological fermentation. For example, ethanol produced from sugar cane is widely used as automotive fuel in Brazil, and ethanol produced from corn is being used as a fuel additive in the United States. Gases and oils are also being produced from various waste sources. For example, thermal depolymerization of waste materials (including plants, food, paper, plastic, paint, cotton, synthetic fabrics, sewage sludge, animal parts, and bacteria) allows for extraction of methane and other compounds similar to that obtainable from petroleum.
The need for alternative fuel sources, and particularly biofuels, also extends to high end uses, such as automobile and jet fuels. Almost all high end use fuels (such as jet engine fuel, diesel engine fuel, and gasoline engine fuel) are presently made from petroleum. Accordingly, such fuels are prepared through refining of crude oils. Refining generally encompasses three basic categories of activities: separation, upgrading, and conversion. During separation, feedstock (e.g., crude oil) is separated into two or more components based on some physical property, typically boiling point. The most common separation method is distillation. Upgrading uses chemical reactions to improve product quality by removing unwanted compounds that impart undesirable properties. For example, "sweetening" relates to removal of mercaptans and other organosulfur compounds, which are corrosive. Hydroprocessing uses hydrogen and a catalyst to remove reactive compounds, such as olefins, sulfur compounds, and nitrogen compounds. Clay treating removes polar compounds by passing the fuel stream over a bed of clay particles. Conversion fundamentally changes the molecular structure of the feedstock, usually by cracking large molecules into small molecules (e.g., catalytic cracking and hydrocracking).
FIG. 1 provides a schematic layout of a modern, fully integrated refinery for preparing various fuel types. As seen in FIG. 1, crude oil is fed to the distillation column where straight-run light and heavy gasoline, kerosene, and diesel are separated at atmospheric pressure. The bottoms from the atmospheric column are vacuum distilled to obtain gas oils for fluid catalytic cracking (FCC) or hydrocracker feed. Previously, the vacuum residue might have been used as a low-value, high-sulfur fuel oil for onshore power generation or marine fuel. To remain competitive today, however, refiners must collect as much high-value product as possible from every barrel of crude, and vacuum residue may now be sent to a residue conversion unit, such as a residue cracker, solvent extraction unit, or coker. These units produce additional transportation fuels or gas oils, leaving an irreducible minimum of residue or coke.
The jet fuel produced by a refinery may be all straight-run or hydroprocessed product, or it may be a blend of straight-run, hydroprocessed, and/or hydrocracked product. Small amounts of heavy gasoline components also may be added. Straight-run kerosene from low-sulfur crude oil may meet all of the jet fuel specification properties. Straight-nm kerosene, though, is normally upgraded by mercaptan oxidation, clay treating, or hydrotreating before it can be sold as jet fuel. The refinery must blend the available streams to meet all performance, regulatory, economic, and inventory requirements. Sophisticated computer programs have been developed to optimize all aspects of refinery operation, including the final blending step. The refiner really has only limited control over the detailed composition of the final jet fuel product. It is determined primarily by the composition of the crude oil feed, which is usually selected based on considerations of availability and cost. Moreover, the chemical reactions that occur in the conversion process are not specific enough to allow for much tailoring of the products.
The consumption of transportation fuels continues to grow worldwide, particularly in light of the rapidly growing need for transportation in emerging economies. For example, just the consumption of jet fuel in the United States increased from 32 million gallons per day in 1974 to 70 million gallons per day in 1999. Although fuel needs are obviously growing, the number of refineries has not kept up with the growing need. According to the National Petrochemicals and Refiners Association, the last refinery built in the United States was completed in 1976. Between 1999 and 2002, refining capacity in the United States rose only 3 percent. Moreover, public perception and environmental concerns make building new refineries more and more difficult. For example, a report from the California Energy Commission notes that even though 10 refineries representing 20% of the state's refining capacity were closed between 1985 and 1995, it is unlikely that new refineries will be built in California. Accordingly, not only is there a need for increased amounts of transportation fuels, there is also a need for alternative sources (to combat dwindling petroleum supplies and the vicissitudes of the crude oil market) and alternative methods of preparing fuels.
In its Broad Agency Announcement (BAA) 06-43 posted Jul. 5, 2006, the Defense Advanced Research Projects Agency (DARPA) Advanced Technology Office (ATO) began soliciting proposals for biofuels to explore energy alternatives and fuel efficiency efforts to reduce reliance on oil to power its aircraft, ground vehicles, and non-nuclear ships. DARPA's BAA06-43 particularly sought efforts to develop a process that efficiently produces a surrogate for petroleum based military jet fuel (such as the current standard fuel, JP-8) from oil-rich crops produced by either agriculture or aquaculture (including but not limited to plants, algae, fungi, and bacteria) and which ultimately can be an affordable alternative to petroleum-derived JP-8.
Biodiesel has been proposed as an alternative source for jet fuel production; however, current biodiesel alternative fuels are produced by transesterification of triglycerides extracted from agricultural crop oils. Specifically, fats are reacted with alcohols and converted to alkyl esters (biodiesel) followed by conversion of biodiesel to jet fuel. The overall reaction is provided below in Formula (1),CH2(OCOR1)CH(OCOR2)CH2(OCOR3)+3ROH+(catalyst)→R1OCOR+R2OCOR+R3OCOR+CH2OHCHOHCH2OH  (1)wherein R1, R2, and R3 represent possibly distinct hydrocarbon chains. As seen in Formula (1), one molecule of triglyceride is combined with three alcohol molecules to produce three molecules of biodiesel and one molecule of glycerol. Thus, the transesterification reaction converts the triglyceride triester to three fatty acid alkyl monoesters. This process unacceptably yields a blend of methyl esters (biodiesel) that is 25% lower in energy density than JP-8 and exhibits unacceptable cold-flow features at the lower extreme of the required JP-8 operating regime (−47° C.). For example, kinetic viscosity at 40° C. of fuel prepared in this manner is in the range of 1.9 to 6.0 centistokes, but the viscosity of an acceptable jet fuel should be in the range of about 1.2 centistokes. Further, it is common for such fuels to have a freezing point in the range of about 0° C. Moreover, as feedstock cost is the primary production cost driver in the preparation of jet fuel from biomass, there has heretofore been no process for preparing jet fuel from biomass that is affordable and utilizes a suitably available necessary feedstock material.
There is likewise an increasing need and desire to establish viable alternative fuel sources for other transportation vehicles, particularly automobiles. Alternative fuels, as defined by the Energy Policy Act of 1992 (EPAct), include ethanol, natural gas, propane, hydrogen, biodiesel, electricity, methanol, and p-series fuels. As previously pointed out, biofuels represent a potentially limitless fuel supply that has heretofore been virtually inaccessible. The ability to use biomass as a source for automobile fuels, such as gasoline or diesel, could not only potentially provide lowered gasoline prices due to increased supply but also lessen the demand for crude oil and stem the fear of waning reserves.
Vegetable oils, animal fats, and algae lipids can be converted to a combination of liquid and gaseous hydrocarbons by transesterification, deoxygenation, pyrolysis, and catalytic cracking processes. All of these processes have been developed to varying degrees over the past 100 years. To convert these fuelstocks into fuel, some combination of these processes can be employed, and optimal combination is a function of both the fuelstock and the desired properties of the fuel product. The present invention provides a process for preparing fuel from biomass.

This patent is subject to a terminal disclaimer.

Process for conversion of biomass to fuel


A method for charging an intermediate-circuit capacitor for a welding device, includes feeding a voltage from a first chopping section of a first half-cycle of an AC voltage into the intermediate circuit capacitor, the first chopping section beginning at a first phase-related starting time; and feeding a voltage from a second chopping section of a second half-cycle of the AC voltage following the first half-cycle into the intermediate circuit capacitor, the second chopping section beginning at a second phase-related starting time, which is earlier than the first phase-related starting time.

The present disclosure relates to a method for charging an intermediate circuit capacitor for a welding device, to a control device for charging an intermediate circuit capacitor for a welding device and to a corresponding computer program.
A resistance welding device usually has an intermediate circuit electrolytic capacitor battery. These electrolytic capacitors cannot be connected directly to the power supply system, but are first charged with a low current. This precharging can be performed by a series power resistor, which limits the current. The electrolytic capacitors can also be charged by a charging switched mode power supply, which charges the electrolytic capacitors, for example with a constant current.

Method and control device for charging an intermediate circuit capacitor for a welding device


A lithographic projection apparatus comprises a contaminant trap (10) for trapping debris from the radiation source (LA) or from the resist (RL) on a substrate (W), which trap comprises two sets (11,12) of channels (20,21:30,31) arranged radially around the optical axis of the projection beam (PB) with a space (13) between them. Gas is supplied to the space. The flow resistance of the channels ensures that the gas pressure outside the trap (10) is much lower then that inside.

The present invention relates to a lithographic projection apparatus comprising:
a radiation system for supplying a projection beam of radiation;
a support structure for supporting patterning means, the patterning means serving to pattern the projection beam according to a desired pattern;
a substrate table for holding a substrate;
a projection system for projecting the patterned beam onto a target portion of the substrate;
at least one chamber enclosing at least part of at least one of the radiation system, the patterning means, the substrate and the projection system, and
a contaminant trap arranged in the path of the projection beam.
The invention also relates to a method for manufacturing devices, which method uses the apparatus.
The term xe2x80x9cpatterning meansxe2x80x9d as here employed should be broadly interpreted as referring to means that can be used to endow an incoming radiation beam with a patterned cross-section, corresponding to a pattern that is to be created in a target portion of the substrate. Generally, the said pattern will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit or other device (see below). Examples of such patterning means include:
a mask. The concept of a mask is well known in lithography, and it includes mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. Placement of such a mask in the radiation beam causes selective transmission (in the case of a transmissive mask) or reflection (in the case of a reflective mask) of the radiation impinging on the mask, according to the pattern on the mask. In the case of a mask, the support structure will generally be a mask table, which ensures that the mask can be held at a desired position in the incoming radiation beam, and that it can be moved relative to the beam if so desired.
a programmable mirror array. An example of such a device is a matrix-addressable surface having a visco-elastic control layer and a reflective surface. The basic principle behind such an apparatus is that (for example) addressed areas of the reflective surface reflect incident radiation as deflected radiation, whereas non-addressed areas reflect incident radiation as non-deflected radiation. Using an appropriate filter, the said non-deflected radiation can be filtered out of the reflected beam, leaving only the deflected radiation behind; in this manner, the beam becomes patterned according to the addressing pattern of the matrix-addressable surface. The required matrix addressing can be performed using suitable electronic means. More information on such mirror arrays can be gleaned, for example, from U.S. Pat. Nos. 5,296,891 and 5,523,193, which are incorporated herein by reference. In the case of a programmable mirror array, the said support structure may be embodied as a frame or table, for example, which may be fixed or movable as required.
a programmable LCD array. An example of such a construction is given in U.S. Pat. No. 5,229,872, which is incorporated herein by reference. As above, the support structure in this case may be embodied as a frame or table, for example, which may be fixed or movable as required.
For purposes of simplicity, the rest of this text may, at certain locations, specifically direct itself to examples involving a mask and mask table; however, the general principles discussed in such instances should be seen in the broader context of the patterning means as hereabove set forth.
Lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, the patterning means may generate a circuit pattern corresponding to an individual layer of the IC. This circuit pattern can be imaged onto a target portion (e.g. comprising one or more dies) on a substrate (silicon wafer) that has been coated with a layer of radiation-sensitive material (resist). In general, a single wafer will contain a whole network of adjacent target portions that are successively irradiated via the projection system, one at a time. In current apparatus, employing patterning by a mask on a mask table, a distinction can be made between two different types of machine. In one type of lithographic projection apparatus, each target portion is irradiated by exposing the entire mask pattern onto the target portion in one go; such an apparatus is commonly referred to as a wafer stepper. In an alternative apparatusxe2x80x94commonly referred to as a step-and-scan apparatusxe2x80x94each target portion is irradiated by progressively scanning the mask pattern under the projection beam in a given reference direction (the xe2x80x9cscanningxe2x80x9d direction) while synchronously scanning the substrate table parallel or anti-parallel to this direction. Since, in general, the projection system will have a magnification factor M (generally  less than 1), the speed V at which the substrate table is scanned will be a factor M times that at which the mask table is scanned. More information with regard to lithographic devices as here described can be gleaned, for example, from U.S. Pat. No. 6,046,792, incorporated herein by reference.
In a manufacturing process using a lithographic projection apparatus, a pattern (e.g. in a mask) is imaged onto a substrate that is at least partially covered by a layer of radiation-sensitive material (resist). Prior to this imaging step, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures, such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the imaged features. This array of procedures is used as a basis to pattern an individual layer of a device, e.g. an IC. Such a patterned layer may then undergo various processes such as etching, ion-implantation (doping), metallization, oxidation, chemo-mechanical polishing, etc., all intended to finish off an individual layer. If several layers are required, then the whole procedure or a variant thereof, will have to be repeated for each new layer. Eventually, an array of devices will be present on the substrate (wafer). These devices are then separated from one another by a technique such as dicing or sawing, whence the individual devices can be mounted on a carrier, connected to pins, etc. Further information regarding such processes can be obtained, for example, from the book xe2x80x9cMicrochip Fabrication: A Practical Guide to Semiconductor Processingxe2x80x9d, Third Edition, by Peter van Zant, McGraw Hill Publishing Co., 1997, ISBN 0-07-067250-4, incorporated herein by reference.
The term xe2x80x9cthe projection systemxe2x80x9d should be broadly interpreted as encompassing various types of projection system, including refractive optics, reflective optics, and catadioptric systems, for example. The radiation system may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation. Further, the lithographic apparatus may be of a type having two or more substrate tables (and/or two or more mask tables). In such xe2x80x9cmultiple stagexe2x80x9d devices the additional tables may be used in parallel or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposures. Twin stage lithographic apparatus are described, for example, in U.S. Pat. No. 5,969,441 and WO 98/40791, incorporated herein by reference.
In order to be able to image smaller features, it has been proposed to use extreme ultraviolet radiation (EUV) with a wavelength in the range of 5 to 20 nm, particularly 13 nm, or a charged particle beam, e.g. an ion beam and an electron beams, as the exposure radiation in a lithographic apparatus. These types of radiation require that the beam path in the apparatus be evacuated to avoid beam scatter and absorption. Because there is no known material suitable for making a refractive optical element for EUV radiation, EUV lithographic apparatus must use mirrors in the radiation (illumination) and projection systems. Even multilayer mirrors for EUV radiation have relatively low reflectivity""s and are highly susceptible to contamination, further reducing their reflectivity""s and hence throughput of the apparatus. This imposes further requirements on the vacuum level that must be maintained and necessitates especially that hydrocarbon partial pressures be kept very low.
At the same time, plasma radiation sources and the resist are substantial sources of contaminants that must be kept out of the illumination and projection systems. A discharge plasma source, for example, uses a discharge to create very hot partially ionized plasma, which emits EUV radiation. The plasma gas, which is often xenon (Xe), and debris from the source must be kept from entering the illumination system. At the other end of the apparatus, the radiation incident on the resist to expose it causes ejection of debris and by-products by a sputtering process. It is necessary to prevent both source and resist debris from reaching the illumination and projection systems.
EP-A-0 957 402, incorporated herein by reference, discloses a system for preventing resist debris entering the projection system. This system comprises a simple tube, preferably conical, which surrounds the projector beam between the projection system enclosure and the substrate. A gas flow in the tube entrains resist debris to prevent it entering the projection system enclosure.
WO 99/42904, incorporated herein by reference, discloses a contaminant trap, called filter, for trapping source debris which comprises a plurality of foils or plates, which may be flat or conical and are arranged radial around the radiation source. The source, the filter and the projection system may be arranged in a buffer gas, for example krypton whose pressure is 0,5 Torr. The contaminant particles then take on the temperature of the buffer gas, for example room temperature thereby sufficient reducing the particles velocity before they enter the filter. The pressure in the known contamination trap is equal to that of its environment. This trap is arranged at 2 cm from the source and its plates have a length, in the propagation direction of the radiation, of at least 1 cm and preferably 7 cm. This design requires relative large and thus costly collecting and guiding/shaping optics to bundle and shape the source radiation and guide it to the mask.
It is an object of the present invention to provide an improved device for trapping debris, such as may be emitted by a plasma source or from resist exposed to EUV radiation.
This and other objects are achieved according to the invention in a lithographic apparatus as defined in the opening paragraph, which is characterized in that contaminant trap comprises at least two sets of channels arranged substantially parallel to the direction of propagation of said projection beam, which sets are spaced apart from each other along an optical axis of said projection beam, and means for supplying a flushing gas to the space between said two sets of channels.
A channel is understood to mean an elongated portion of space wherein a portion of the projection beam propagates. Plate members or foils separate such a channel from neighboring channels.
By providing two sets of channels, effectively forming two particle traps, and supplying gas to the space between them, a high gas pressure to trap the contaminant particles can be achieved, whilst the high flow resistance of the particle traps ensures that leakage is minimized. The new trap design allows the gas pressure in the trap to be orders of magnitude higher than outside the trap. The trap efficiency is increased considerably, which allows the trap to be considerably shorter, i.e. more compact so that the size and costs of the collecting optics can be decreased considerably. If sufficient exhaust pumping capacity is provided, the pressure outside the trap can be kept at least 10 or 100 times less than the pressure inside the trap.
In order to provide sufficient resistance to gas flow to maintain the pressure differential between the space between the two sets of channels and outside the trap, the channels defined by the plate member preferably have an aspect ratio (length/width) of greater than 8.
Preferably, the flow of gas through the traps is sufficiently fast that the volume of the trap is emptied by the exhaust pumps in less than, preferably less than half, the mean time taken for a gas molecule to diffuse through either one of the sets of channels. In this way, it is possible to ensure that contaminant particles that do not stick to the plate members or foils of the channels are entrained and exhausted with the flow of flushing gas.
The contaminant trap can be used between a radiation source and the illumination system comprised in said radiation system to capture source debris, especially where the source is a plasma source.
The invention also relates to a device manufacturing method comprising the steps of:
providing a substrate that is at least partially covered by a layer of radiation-sensitive material;
providing a projection beam of radiation using a radiation system;
removing contaminant particles from the projection beam using a contaminant trap;
using patterning means to endow the projection beam with a pattern in its cross-section;
projecting the patterned beam of radiation onto a target portion of the layer of radiation-sensitive material. This method is characterized in that the step of removing contaminant particles comprises sending the projection beam successively through at least two sets of channels, which are spaced apart from each other in the direction of propagation of the projection beam and supplying a flushing gas to the space between the said two sets of channels.
Although specific reference may be made in this text to the use of the apparatus according to the invention in the manufacture of ICs, it should be explicitly understood that such an apparatus has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms xe2x80x9creticlexe2x80x9d, xe2x80x9cwaferxe2x80x9d or xe2x80x9cdiexe2x80x9d in this text should be considered as being replaced by the more general terms xe2x80x9cmaskxe2x80x9d, xe2x80x9csubstratexe2x80x9d and xe2x80x9ctarget portionxe2x80x9d, respectively.
In the present document, the terms xe2x80x9cradiationxe2x80x9d and xe2x80x9cbeamxe2x80x9d are used to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (extreme ultra-violet radiation, e.g. having a wavelength in the range 5-20 nm).

Lithographic apparatus and device manufacturing method


A method for controlling operation of a secure execution mode-capable processor includes receiving access requests to a plurality of addressable locations within a system memory. The method may further include preventing the access requests from completing in response to determining that the secure execution mode-capable processor is operating in a secure execution mode.

1. Field of the Invention
This invention relates to computer systems employing secure execution mode-capable processors and, more particularly, to controlling the secure execution mode-capable processor in system management mode.
2. Description of the Related Art
Modern computer systems are revolutionizing the way people live. This is particularly true for system platforms including microprocessors employing the x86 system architecture. The openness of x86-based systems to a myriad of owner-installable third-party peripheral devices and applications has enabled a broad marketplace of hardware and software vendors that has fostered competition, innovation, and evolution. An example of such evolution is the now widespread use of the platform as a digital communication and media system of ever-increasing quality and capability. In concert with the Internet, these system platforms are clearly revolutionizing mass distribution of digital content, allowing on-demand access to newspapers, real-time weather conditions and radio stations from around the world, on-line banking and shopping, and audio and video-based entertainment.
Since the x86 platform is an open architecture, devices typically have vendor-supplied drivers which run in Kernel mode in order to access the devices, and certain software applications may include Kernel mode components. Thus, although the open architecture may have advantages and may still provide a large degree of protection against accidental interference of one application with another, the current architectural protection mechanisms may be exposed in this environment to unwanted manipulation.
Computer systems including microprocessors employing the x86 architecture include features designed to protect against applications interfering with each other. For example, x86-based operating systems rely on two features of the x86 Protected mode architecture to provide an environment where applications are isolated from each other, and critical operating system code and data is isolated from applications: 1) paged virtual memory, and 2) execution privilege level.
Paged virtual memory allows the Operating System (OS) to define a separate virtual address space for each application, and to selectively map individual pages of physical memory into each of those virtual address spaces through a set of address translation tables. This provides each application with its own private section of physical memory for code and data that may be inaccessible to other applications. The virtual memory mechanism may also allow the OS to selectively map pages of physical memory into multiple virtual address spaces, and to selectively designate such pages in virtual space as read-only. This shared mapping capability may also allow a copy of the OS Kernel itself to reside in each application's address space, and may likewise allow shared mappings of peripheral device access ports and associated device driver routines, thus providing applications with efficient access to OS services without requiring costly address space switches. But the OS portion of the address space necessarily includes system data areas that OS code must be able to modify, and which must still be protected from application code. The read-only designation may not provide proper protection for such areas.
The x86 architecture also defines four privilege levels, 0 through 3, which are assigned to regions of code by the OS and kept in code segment descriptors. Typically, the privilege level of currently executing code or procedure will be stored as the Current Privilege Level (CPL). Thus the privilege levels are commonly referred to as CPL0 through CPL3. Using these privilege levels, certain system resources are accessible only to code executing at the proper level. The paged virtual memory architecture may allow access to pages of virtual memory to be restricted by privilege level. Although four privilege levels are defined, only the CPL0 and CPL3 levels are typically used by mainstream operating systems because the paged virtual memory architecture does not distinguish CPL1 or CPL2 from CPL3. CPL0 is commonly referred to as Kernel mode and is the most privileged level, while CPL3 is commonly referred to as User mode and is the least privileged level. OS code and data are typically assigned to CPL0 while application code and data are assigned to CPL3. CPL0 execution privilege does not override read-only protection; the two attributes are independent. Code segment descriptors are used to assign these levels.
In addition to this memory protection, all processor control registers, including those that control virtual memory operation, are by architectural definition accessible only at CPL0. In addition, special control transfer instructions are typically required to switch execution from one segment to another, and hence to switch privilege levels. These instructions allow the OS to limit the targets of such control transfers to specific entry points in OS-controlled code, hence an application may not change privilege level without simultaneously handing control over to the OS.
The isolation of address spaces from each other, and of OS memory from applications, may be completely controlled by the contents of the virtual memory address translation tables. The translation tables define the virtual-to-physical page mappings that isolate one application's memory from another's, and also the read-only and privilege level attributes that protect shared libraries and the OS. The tables themselves are memory-resident data structures, and contain translation entries that map them into the shared OS memory area and restrict access to them to Kernel mode code.
The existing protection mechanisms would seem to provide adequate protection for applications and the operating system. In a well-behaved system, (e.g. correct application of these mechanisms by the operating system, and correct operation of the OS code that controls these mechanisms, and that all other code which runs in Kernel mode does not interfere with this) they do. However, typical x86-based systems include such a large amount of Kernel-mode code, not just from the OS vendors but from many independent sources, that it may be impossible for anyone to assure that such interference, whether accidental or otherwise cannot occur. Further, it is possible that operational modes such as the System Management Mode (SMM) that bypass the virtual memory protection mechanisms and access system memory directly may compromise sensitive system data.
Depending on the type of operation that a user is performing and the type of software application that is running, information stored within or running on the computer system may be vulnerable to outside access. Thus, it may be desirable to improve security and thereby possibly make x86 architecture systems less vulnerable to such access.

Method and apparatus for controlling operation of a secure execution mode-capable processor in system management mode


A photocoupler includes a LED for emitting light in accordance with an input electrical signal, a driver for supplying an electrical signal to the LED, a light receiver placed face to face with the LED and having a photodiode for receiving light emitted by the LED, and a half mirror placed between the LED and the photodiode, for changing the direction of light emitted by the LED. The photocoupler controls the current to be supplied to the LED in accordance with the reflected light by the half mirror to uniformize the light emission intensity of the LED.

1. Field of the Invention
The present invention relates to an optical coupling device including a light emitting element and a light receiving element and particularly to an optical coupling device capable of controlling light emission intensity from the light emitting element.
2. Description of Related Art
A photocoupler is used in various locations such as factories, plants, and electrical household appliances for the purpose of eliminating a large common mode noise and ensuring safety. The photocoupler has a configuration where a light emitting element such as a light emitting diode (LED) which emits light in accordance with an input signal and a light receiving element such as a photodiode which outputs a current in accordance with an incident light intensity are optically coupled, and its input and output are electrically disconnected.
A large common mode noise occurs often in the sites where high-power equipment and high-sensitivity electronic equipment coexist with a difference in power supply voltage exceeding 1000V, such as factories and plants. There has been a recent demand for controlling AC servos and inverters which are used in factories or the like highly accurately. To meet this demand, a photocoupler is required to exhibit higher common-mode rejection (CMR) and lower pulse width distortion, and various techniques have been proposed therefor, including Japanese Unexamined Patent Application Publication No. 2002-353495 (Shimizu), for example.
FIG. 5 illustrates the configuration of a photocoupler 1 taught by Shimizu. The photocoupler 1 converts an electrical signal which is input through an input terminal 2 into an optical signal in a light emitter 3, then converts the optical signal back to an electrical signal in a light receiver 4 on the output side, and finally outputs the electrical signal through an output terminal 5. A light emitting element on the light emitter 3, such as a LED, and a light receiving element on the light receiver 4, such as a photodiode, are disposed face to face each other in close proximity. A light transmitting resin 6 having a prescribed dielectric constant is filled in the gap between the light emitting element and the light receiving element. The light emitter 3, the light receiver 4, and the light transmitting resin 6 are sealed in one package by a light shielding resin 7. The input-side circuit and the output-side circuit are thereby electrically shielded from one another, thereby enabling signal transmission under the condition where devices are electrically disconnected.
FIG. 6 illustrates the configuration of the light receiver 4 taught by Shimizu. As shown in FIG. 6, the light receiver 4 includes a photodiode D1 and a dummy photodiode D2 which are arranged adjacent to each other. The photodiode D1 receives an optical signal from the light emitting element. A light receiving surface of the dummy photodiode D2 is shielded from light by a cathode electrode. The output currents from the photodiodes D1 and D2 are respectively converted into voltages by current-voltage conversion amplifiers A1 and A2. The voltages converted by the current-voltage conversion amplifiers A1 and A2 are then compared with each other by a hysteresis comparator 8, and finally output as waveform-shaped pulses. This enables improvement in a common-mode rejection ratio (CMRR).
The light receiver 4 further includes impedance variable circuits Z1 and Z2 in which impedance decreases as the level of a current input to the amplifier increases. In such a configuration, if a current signal Ipd is Low, the impedance of the impedance variable circuit Z1 increases. This reduces the bandwidth of the amplifier to suppress the high-frequency component of a noise and substantially equalizes the values of Z1 and Z2. The characteristics of the current-voltage conversion amplifiers A1 and A2 are thereby aligned to improve the CMRR. On the other hand, although the reduction of the bandwidth of the amplifier causes rounding of the received waveform, it is output because a threshold level of the hysteresis comparator 8 is constant. The pulse waveform is thereby distorted, resulting in large pulse width distortion. If, on the other hand, the current signal Ipd is High, the impedance of the impedance variable circuit Z1 decreases. This enlarges the bandwidth of the amplifier to achieve low pulse width distortion. Instead, the high frequency component of a noise cannot be suppressed, and the values of Z1 and Z2 thereby differ. The characteristics of the current-voltage conversion amplifiers A1 and A2 are thereby unbalanced to deteriorate the CMRR.
The light emission intensity of LED varies by manufacturing fluctuation, changes over time, ambient temperature variation, and so on. The non-uniform light emission intensity causes fluctuation in the current signal Ipd which is detected by the light receiver 4. In Japanese Unexamined Patent Application Publication No. 9-172225 (Asami et. al.), a technique of monitoring a part of optical power and stabilizing the optical power is disclosed. However, it contains no suggestion for applying this technique to a photocoupler.
According to the related arts, the CMRR and the pulse width distortion are in the relation of trade off each other with respect to a change in the current signal Ipd, thus failing to achieve both high CMR and low pulse width distortion. As a photocoupler operates at higher speed, the restriction of pulse width distortion becomes more strict, i.e. from 100 ns or lower to 10 ns or lower. It is difficult for the techniques according to the related arts to satisfy such restriction.
In view of the foregoing, there is an increasing need for an optical coupling device capable of controlling the light emission intensity from a light emitting element and achieving both high CMR and low pulse width distortion.

Optical coupling device with a detecting element in the driver that provides uniform intensity of an optical signal


A coin discriminating device has a sensor electrode and an oscillator. The oscillator is coupled to the sensor electrode. The oscillator generates an output signal with a frequency which is capacitively controllable. A frequency detector detects a frequency deviation in the oscillator output signal, caused by a variation in capacitance at the sensor electrode when a coin is positioned in the vicinity of the sensor electrode. A processing device determines the thickness of the coin from the frequency deviation. The coin discriminating device is arranged such that the variation in capacitance occurs between the sensor electrode and a surface of the coin.

Coin discriminators are used for measuring different physical characteristics of a coin in order to determine its type (e.g. its denomination, currency or authenticity). Various dimensional, electric and magnetic characteristics are measured for this purpose, such as the thickness and diameter of the coin, its electric conductivity and its magnetic permeability. Coin discriminators are commonly used in coin handling machines, such as coin counting machines, coin sorting machines, vending machines, gaming machines, etc. Examples of previously known coin handling machines are for instance disclosed in WO97/07485 and WO87/07742.
Starting with the electric characteristics of coins, EP-B-300,781 and EP-B-0,119,000 describe previously known ways of measuring coin conductivity. A transmitter coil is driven with a pulsed supply voltage so as to generate a magnetic pulse, which is induced in a coin, which moves along a coin path or rail past the transmitter coil. The eddy currents thus generated in the coin in turn produce a magnetic field, which is monitored or detected by a receiver coil. The receiver coil may be a separate coil or may alternatively be constituted by the transmitter coil itself having two operating modes. By monitoring the decay of the eddy currents induced in the coin, a value representative of the coin conductivity may be obtained, since the rate of decay is a function thereof. A coin discriminator of a similar type, albeit especially adapted for bimetallic coins, is disclosed in WO99/39311.
As regards the magnetic characteristics of coins, e.g. their magnetic permeability, U.S. Pat. No. 4,483,431 relates to a coin discriminator, where a permanent magnet and a Hall effect device is used for checking the magnetic properties of the coin, when it passes the Hall effect device. Moreover, U.S. Pat. No. 5,119,916 discloses a sensor for validating subway tokens. The sensor has two pairs of permanent magnets and Hall effect sensors, which determine the magnetic characteristics (and consequently the permeability) of the respective token.
Various methods are known for determining the coin diameter in coin discriminators. According to PCT GB88/00592 a coin is exposed to high-frequency magnetic pulses from a pair of coils. When the coin passes the coils, the magnetic field is shielded, and a pickup coil is used for determining the coin diameter in response to this momentary shielding. Alternatively, the coin diameter may be determined optically by using a line of optical detectors located opposite a light source. When a coin passes between the optical detectors and the light source, a certain number of the optical detectors are momentarily shielded or cut off by the passing coin. The coin diameter follows immediately from the number of shielded optical detectors.
Also the coin thickness may be determined by optical arrangements similar to the one described above for measuring the coin diameter. Alternatively, as disclosed in EP-B-300,782, an ultrasound detector may be used for determining the thickness of a coin. Furthermore, EP-A-343,871 discloses a capacitive coin validation method, involving a pair of electrode assemblies on either sides of a coin path. Most specifically, in EP-A-343,871 the pair of electrode assemblies comprises sensor electrodes and guard ring electrodes that are disposed on either sides of the coin path. The sensor electrodes are driven with an oscillating signal from dual resonant circuits, so that when a coin passes the electrodes during the validation thereof, the inter-electrode capacitance is altered. Thus, in effect, the sensor electrodes act as first and second capacitor plates that form a capacitor, the capacitance of which is changed by the presence of the coin. Thereby, also the resonating signals from the resonant circuits are changed. In EP-A-343,871, the coin must be electrically isolated from the electrode assemblies, thereby requiring electrical isolation in the coin path.
Thus, the device in EP-A-343,871 requires an electrically isolated coin path and, moreover, first and second capacitor plates (the electrode assemblies) placed on either side of the coin path.

Coin discriminating device and method, and a coin handling machine including such a device and method


A single format of MAC control message may be used for the addition, deletion, or rearrangement of users in a group within a wireless network. In some cases, a change in the nature of the group may be implemented immediately upon receipt of a positive acknowledgement. A mobile station may determine its ACID without maintaining information about the previous ACID or startup frame.

This relates generally to wireless communications.
Group resource allocation is a wireless communication technique to allocate resources to multiple users as a group in order to save control overhead and increase network capacity. It may be utilized, for example, in a WiMAX network. (IEEE Std. 802.16-2005, IEEE Standard for Local and Metropolitan Area Networks, Part 16: Interface for Fixed Broadband Wireless Access Systems, 802.16-2009 (802.16e) and 802.16m, IEEE New York, N.Y. 10016).
Generally, signaling information for allocations using group resource allocation is transmitted by way of a so-called MAP information element (IE) transmitted from a base station to a mobile station. The first MAP IE used by group resource allocation mechanism is called the group configuration MAP IE, which is used to add a mobile station to a group. Deletion and rearrangement of mobile stations within a group is performed in the group resource allocation IE that also signals the allocation information for the mobile stations within a group.
Since the MAP IEs also contain allocation information, the MAP IEs need to be parsed with minimum delay. The time critical processing of MAP IEs is called "online processing". However, the mobile station addition, deletion, and rearrangement processes are "background processing" which are not time-critical and can be performed on a slower scale. The inclusion of background processing in MAP IEs slows down the parsing of MAP IEs causing undesirable delay for online processing. This makes the mobile station more expensive in terms of cost and power consumption, in some cases.

Allocating group resources for wireless communications


The thermally-assisted magnetic recording head of the invention includes: a waveguide; a magnetic pole; a cladding layer provided between the waveguide and the magnetic pole; and a plasmon generator embedded in the cladding layer. The cladding layer includes a first cladding section located on a side close to an air-bearing surface and a second cladding section located on a side far from the air-bearing surface, and a thermal expansion coefficient of the first cladding section is larger than a thermal expansion coefficient of the second cladding section.

1. Field of the Invention
The invention relates to a thermally-assisted magnetic recording head in which near-field light is applied to a magnetic recording medium to lower a coercivity thereof so as to record information, and to a head gimbal assembly, a head arm assembly, and a magnetic recording unit that each include the thermally-assisted magnetic recording head.
2. Description of Related Art
In the past, a magnetic recording unit such as a Hard Disk Drive (HDD) has been used for recording and reproducing magnetic information (hereinafter, simply referred to as "information").
The magnetic recording unit typically includes, in the housing thereof, a magnetic recording medium (a magnetic disk) in which information is recorded, and a magnetic read write head that performs write operation and read operation of the information. The magnetic read write head is formed on a surface of a magnetic head slider, and has an air-bearing surface facing the magnetic disk. The magnetic head slider is attached to an end of a suspension, and the other end of the suspension is attached to a pivotable arm.
In recent years, along with a progress in higher recording density (higher capacity) of the magnetic disk, improvement in performance of the magnetic read write head has been demanded. Therefore, as a magnetic recording system capable of addressing higher recording density, a so-called thermally-assisted magnetic recording system has been studied. In the thermally-assisted magnetic recording system, a magnetic disk in which coercivity of a magnetic recording layer is large is used, and a magnetic field for recording (recording magnetic field) and heat are applied to a recording region (a region in which information is recorded) of the magnetic recording layer at the time of information recording. Therefore, coercivity of the recording region is lowered with increase in temperature as well as the recording region is magnetized, and thus information is recorded.
In the thermally-assisted magnetic recording system, near-field light is generally used for supplying heat to a magnetic disk. Along with this, a magnetic recording head of the thermally-assisted magnetic recording system (a thermally-assisted magnetic recording head) includes a light source generating laser light, a waveguide allowing the laser light to propagate therethrough, a magnetic pole generating a recording magnetic field, a plasmon generator provided in a region between the waveguide and the magnetic pole, and a cladding layer allowing the plasmon generator to be embedded in the region between the waveguide and the magnetic pole. In the thermally-assisted magnetic recording head, when surface plasmons are generated by the plasmon generator, near-field light is generated in the vicinity of the air-bearing surface by using the surface plasmons, and therefore heat is supplied together with the recording magnetic field to the magnetic disk.
In the case where such near-field light is used, in Japanese Patent No. 4104584, surface plasmon polariton coupling is used to prevent overheating of a plasmon generator due to direct application of light. In this case, the light propagating through a waveguide (guided light) is not directly applied to the plasmon generator, and the guided light is coupled with the plasmon generator through evanescent coupling, and thus surface plasmon polaritons are generated on a surface of the plasmon generator.
In the case where such surface plasmon polaritons are used, in U.S. Pat. No. 8,089,831, to concentrate the guided light effectively, a width of a plasmon generator is decreased in the vicinity of an air-bearing surface. Specifically, the plasmon generator includes a forward section having a uniform width and a backward section having a width larger than the uniform width, in order backward from the air-bearing surface.
During operation of the thermally-assisted magnetic recording head, since temperature is drastically increased in the vicinity of the air-bearing surface where the near-field light is generated, thermal expansion occur. As a result, large stress is applied to the plasmon generator, and thus the plasmon generator is easily agglomerated (shrunk). In this case, in particular, the forward section close to the air-bearing surface is likely to be increased in temperature as compared with the backward section, and the forward section having a volume relatively smaller than that of the backward section is easily exposed to high pressure environment, and therefore the forward section is more easily agglomerated.
If the forward section is agglomerated, the plasmon generator gets away from the magnetic disk at the time of recording, and therefore the near-field light is less likely to be generated in the vicinity of the air bearing surface. As a result, since it is difficult to control the coercivity of the magnetic disk, recording performance is deteriorated.
To prevent deterioration of the recording performance caused by the agglomeration, in Japanese Unexamined Patent Application Publication No. 2011-008899, an adhesive layer is provided between a plasmon generator and a dielectric body. In a forward section having a small volume, however, a surface area (an area contacted to the adhesive layer) thereof is also small, and thus it is difficult to suppress agglomeration of the forward section only by providing the adhesive layer.
Accordingly, it is desirable to provide a technique capable of suppressing agglomeration of a plasmon generator in order to obtain superior recording performance.

Thermally-assisted magnetic recording head including first and second cladding sections having different characteristics


A circuit comprises a power source, an Open Loop Reactance Matching Circuit Control Signal Generator (OLRMCCSG), an Open Loop Reactance Matching (OLRM) circuit, and a load. The power source supplies an input voltage and an input current used to drive the load. The load is an inductive type load or a capacitive type load. If the power source operates as a voltage source, then the OLRMCCSG uses input voltage information to control the OLRM circuit to generate a reactance matching voltage that is phase delayed with respect to the input voltage. If the power source operates as a current source, then the OLRMCCSG uses input current information to control the OLRM circuit to generate a reactance matching current that is phase delayed with respect to the input current. The reactance matching voltage or the reactance matching current causes the input voltage and the input current to be in phase.

Power circuits generally include a power source and a load. Electrical energy is output from the power source in the form of Direct Current (DC) or Alternating Current (AC) power that is supplied to and used to drive the load. The load has an input impedance and an output impedance. To maximize transfer of power to the load, it is desirable to design power circuitry such that the input impedance of the load matches the output impedance. This is referred to in power electronics as impedance matching or reactance matching. Impedance or reactance matching is often desirable to increase the overall efficiency of power circuitry.


A system is disclosed for determining the position of at least one target by triangulation, comprising two passive sighting devices which measure the intensity of radiation received along a sighting line which scans a vertical sighting plane. They are disposed at a distance from each other along the same vertical axis and are driven in rotation about this common axis so that their sighting planes merge. A circuit extracts the angular coordinates of the target, relative to each of the sighting devices, and computes the distance of the target by triangulation in the vertical sighting plane.

1. Field of the Invention
The present invention relates to a system for determining the position of at least one target emitting radiation, comprising:
two passive sighting devices, sensitive to said radiation, disposed at a distance from each other and movable in rotation about a substantially vertical common axis, PA1 means for measuring the intensity of the radiation received by each of the sighting devices along a sighting line scanning a substantially vertical sighting plane, common to the two sighting devices, PA1 means for extracting,in response to the intensities measured, the values of the elevation angles of said target relative to the two sighting devices, and PA1 means for computing, in response to the values of the elevation angles, the distance of said target by triangulation in said substantially vertical common sighting plane. PA1 each of the two sighting devices comprises its own means for measuring the intensity of the radiation received, its own drive means for driving it in rotation about said common axis and its own means for measuring its bearing angle, and PA1 means are provided for controlling said means driving in rotation about said common axis, in response to the values of the bearing angles measured, and arranged so that said bearing angles are equal.
Such a system is used on the ground or on board a ship, for example, for monitoring and, as required, designating to a weapons system the targets which menace the site where said system is set up or the ship on board which it is embarked.
2. Description of the Prior Art
A system of the above defined type is already known, described in the British patent application No. 2 070 877. In this system, the two sighting devices are mechanically coupled and mounted on the same turret which is rotatable about a vertical axis. A single device is provided for measuring the intensity of the radiation received, which serves for each of the sighting devices, as well as a single device for rotating the turret.
This system has the drawback of limited accuracy in determining the distance of the target, because the distance between the two sighting devices is also limited, both for mechanical and optical reasons. It is in fact well known that the accuracy of a triangulation system is related to the value of the distance of its base, here the distance between the two sighting devices.
Now, in the known system, it is not possible to increase this distance, for the hollow mechanical structure which supports the upper sighting device becomes too high and too heavy and difficult to drive. In addition, because the optical path of the ray which penetrates through the lower sighting device must be of the same length as the optical path of the ray which penetrates through the upper sighting device, problems arise if the distance between the two sighting devices is too great.
Furthermore, and still for mechanical reasons, it is not possible, in sighting devices, to use lenses having too large a diameter which increase the weight of the rotary mechanical assembly and introduce an imbalance, at least in the case of the upper sighting device.
In addition, the known system involves the use of a semi-reflecting mirror which introduces a measured energy loss, thus reducing the sensitivity correspondingly. Moreover, in the known system, the height of the field common to each of the sighting devices is smaller than that of the field of each of these devices.
Finally, with this known system it is not possible to determine the distances of several sources present at the same time in the sighting plane.

System for determining the position of at least one target by triangulation

Sat(Societe Anonyme de Telecommunications


An array of superconducting bolometers, assembled with a superposed interference layer of graduated thickness, provides a microelectronic detector assembly that discriminates radiation impinging thereon, as a function of wavelength, and that can be used for transform spectroscopy, color-imaging, and the like. The interference coating will preferably be of step-like form, with each plateau of the structure being of the same spatial extent as the bolometer with which it is associated.

Conventional methods of infrared spectroscopy utilize either a small throughput (IR flux) optical element for dispersion, followed by a detector or a detector array, or a large throughput, scanning interferometer followed by a detector. In application of the first technique, the spectrum is accessed directly in the wavelength and frequency domain, while in the second the spectrum is measured in the time domain and then transformed (typically using Fourier algorithms) by a post-measurement calculation to the wavenumber domain.
As is known to those skilled in the art, the first method is relatively simple to implement, but is also of relatively low sensitivity due to the small amount of light throughput involved; in addition, long scanning times are required if the spectral range encompassed is substantial, and the instrument itself must be fairly large if good resolution is to be had. On the other hand, methods using scanning interferometers find wide application in Fourier-transform infrared (FT-IR) spectroscopy and in other specialized applications (e.g., piezoelectric scanning Fabry-Perot interferometers), but the instruments employed can be very complex and expensive, and can lack durability, largely because of their requirement for high-precision moving optics.
Additional limitations, common to both spectroscopy methods described, are related to the materials presently available for IR detectors. Current detector technology is based either upon photoelectric semiconductor materials, which are of a narrow band character, or upon broad-band but low-sensitivity photo-thermal materials, which are of slow response; both kinds of materials are, in addition, difficult to fabricate into satisfactory arrays.

Superconducting detector assembly and apparatus utilizing same


Antenna systems, such as an active antenna system (AAS), can include active and passive electronic components located closely together inside an antenna system. Such systems may benefit from variable adaptation of active antenna system radio frequency signal filtering. An apparatus can include an active part on a first end of a signal path within a sealed enclosure. The apparatus can also include a radiator part on a second end of the signal path within the sealed enclosure. The apparatus can further include an intermediate part, which includes at least one of an additional filter part or a customized passive part, positioned between the active part and the radiator part along the signal path between the first signal side and the second signal side.

1. Field
Antenna systems, such as an active antenna system (AAS), can include active and passive electronic components located closely together inside an antenna system. Such systems may benefit from variable adaptation of active antenna system radio frequency signal filtering.
2. Description of the Related Art
International Telecommunication Union (ITU) requirements describe only worldwide applicable requirements in respect of radio emission. Radio system specific requirements are described by other organizations, such as the 3rd Generation Partnership Program (3GPP). Radio system specific requirements can include long term evolution (LTE), wideband code division multiple access (WCDMA), global system for mobile communication (GSM), and the like. National specific requirements can also be added on to those requirements. For example, the British telecom regulator, Ofcom, has released additional radio requirements for co-location of mobile communication with national Digital Terrestrial Television (DTT) services. For other countries, like the United States, Germany, and so on, other additional requirements may likewise be defined.
In an active antenna system (AAS), variable RF filtering/RF combining may be used. AAS is a system architecture introduced in mobile radio communication. It can be viewed as an evolution from previous base transceiver station (BTS) design, for example remote radio head (RRH). Within RRH design, antenna and active part/passive part are not inseparably connected. Thus, an additional filter part can be easily placed.
FIG. 1 illustrates additional filtering in case of a remote radio head (RRH). As shown in FIG. 1, the remote radio head can include an active part/passive part 120 inside sealed outside enclosure 110. The sealed outside enclosure 110 can include inputs and outputs, such as a supply voltage 130, a data line with data to be transmitted 140, a data line with data received 150, and a control line 160 for control of the RRH. As used herein, the term "sealed" can refer to sealing in terms of ingress protection (IP), electromagnetic compatibility (EMC), not with respect to any desired radio frequency (RF) signals.
The remote radio head active part/passive part 120 can include, for example, baseband processing, up-/downconversion, filtering, radio frequency (RF) power amplification, low noise reception (RX) amplifier, and RF filtering, such as a diplex filter.
Also included can be an additional filter part 170 placed between the active part/passive part 120 and an antenna 180. The additional filter part 170 can include, for example, a bandpass/notch/lowpass filter. The additional filter part 170 can be connected to the active part/passive part 120 by an interface 190.
FIG. 2 illustrates an adaptive antenna system (AAS) setup. As shown in FIG. 2, the AAS can include a combination of an antenna radiator 220 and an active part/passive part 120. These elements can be combined in a compact way. However, as a result, an additional filter part cannot be inserted as in a conventional BTS design. For example, any additional filter part cannot be placed after the AAS itself, since the antennas are already an integral part of the AAS.
The AAS can include the active part/passive part 120 and the radiator part 220 inside sealed outside enclosure 110. The sealed outside enclosure 110 can include inputs and outputs, such as a supply voltage 130, a data line with data to be transmitted 140, a data line with data received 150, and a control line 260 for control of the AAS.
The active part/passive part 120 can include, for example, baseband processing, up-/downconversion, filtering, RF power amplification, a low noise RX amplifier, and RF filtering, such as a diplex filter or a triplex filter to inject another passive signal.
The radiator part 220 can include, for example, a passive antenna distribution network, an antenna matching network, and/or antenna radiation elements. Thus, the radiator part 220 can directly provide an external radio signal 225 without the need for any additional interface.
While the design is compact, in the above mentioned example, several different products may need to be designed and built for several different operators in one country. Moreover, different products may also be needed on a country-by-country basis.
FIG. 2 should be understood as not implying that there is a physical boundary between active part/passive part 120 and radiator part 220. Likewise, the drawing should not be understood as implying that subparts of each schematic section are physically arranged in the way shown. Subparts, as discussed herein, can refer to parts made of one or more elements to achieve a certain function.

Variable adaption of active antenna system radio frequency filtering


A hollow rail structure directly extruded from aluminum in for pocket billiard table is disclosed to have an inner sidewall, an outer sidewall, a top wall, a bottom wall, ribs that define the inside space of the hollow rail into multiple compartments, a cover cloth locating groove longitudinally disposed on the top wall adjacent to the inner sidewall for the positioning of one side of a cover cloth, a longitudinal inside bottom channel longitudinally disposed inside the bottom wall adjacent to the inner sidewall for holding a wooden block for the mounting of the other side of the cover cloth and is fastened to the cover cloth locating groove, a longitudinal inside top channel formed inside the top wall, and a plurality of top locating holes in communication with the inside top channel and the outside space for the mounting of sights.

1. Field of the Invention
The present invention relates to a pocket billiard table and more particularly to a rail structure for pocket billiard table.
2. Description of the Related Art
A conventional pocket billiard table, as shown in FIG. 1, comprises a rectangular tabletop 10, a plurality of rails 11 respectively arranged along the four sides of the table 10, four corner fittings 12 respectively disposed in the four corners of the tabletop 10 and connected between each two adjacent rails 11 and defining with the tabletop 10 a respective pocket 14, and four legs 130 respectively provided at the bottom side of the table 10.
Referring to FIGS. 2 and 3, each rail 11 is formed of a number of wooden blocks 13 that are bonded to one another with glue. Further, each rail 11 has an inner sidewall 15, which is abutted against the tabletop 10 and has an upper sloping surface portion 151 and a lower sloping surface portion 152, a rubber cushion strip 36 bonded to the upper sloping surface portion 151 for stopping against the ball during the game, an outer sidewall 16 opposite to the inner sidewall 15, a locating groove 161 longitudinally formed in the outer sidewall 16 on the middle, a top wall 17 smoothly curved downwards from the topmost edge of the inner sidewall 15 toward the outer sidewall 16 and covered with a layer of ornamental covering 18, and a packing strip 19 fastened to the locating groove 161 and covered on the outer sidewall 16 for protection.
The top wall 17 has a locating groove 171 for the positioning of a locating block 172 to hold down one side of a cover cloth 173, which is covered over the rubber cushion strip 36 and has the other side affixed to the bottom side of the rail 11 by fastening members 174 (for example, nails).
After covering of the ornamental covering 18 on the top wall 17 of the rail 11, holes 111 are formed on the ornamental covering 18 and the top wall 17 of the rail 11, and then sights 112 are affixed to the holes 111 for reference in counting the ball striking angle. The rail 11 further has a plurality of bottom mounting holes 113 for fastening to the table 10 with fastening members.
The aforesaid structure of rail 11 has numerous drawbacks as follows:
1. Because the wooden blocks 13 that form each rail 11 have different density, the rails 11 vary in density. When the ball hits the rubber cushion strip 36, the respective rail 11 gives a different reactive force. This problem affects the ball control and the bouncing speed and direction of the ball.
2. The wooden blocks 13 of the rails 11 may deform due to a significant environmental temperature or humidity change. A deformed rail 11 makes aforesaid problem more serious.
3. The curvature of the top wall 17, the upper sloping surface portion 151 and lower sloping surface portion 152, the locating grooves 161 and 171 and the holes 111 of each rail 11 complicate the fabrication of the rails 11.
4. The consumption of wooden material threatens the ecological environment. It is against environmental protection to fell trees for making pocket billiards tables.

Rail structure for pocket billiard table


A method for manufacturing a semiconductor laser includes the steps of preparing a mold with a pattern surface having recesses, forming a stacked semiconductor layer including a grating layer, forming a resin part on the grating layer, forming a resin pattern portion on the resin part, forming a diffraction grating by etching the grating layer using the resin part as a mask, and forming a mesa-structure on the stacked semiconductor layer. Each of the recesses includes two end portions and a middle portion between the two end portions. A depth of at least one of the two end portions from the pattern surface is greater than that of the middle portion. The step of forming the mesa-structure includes the step of etching the stacked semiconductor layer so as to remove end portions of the diffraction grating in a direction orthogonal to a periodic direction thereof.

1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor laser.
2. Description of the Related Art
Japanese Unexamined Patent Application Publication No. 2009-53271 describes a method for manufacturing a distributed feedback laser diode by using a nano-imprint technique. In this method, a semiconductor layer is patterned by the nano-imprint technique to form a diffraction grating of a distributed feedback laser diode. Also, a microfabrication method in which a nano-imprint technique is used is described in M. W. Lin, et. al., "Planarization for Reverse-Tone Step and Flash Imprint Lithograph", Proceedings of SPIE 6151, pp. 61512G (2006).
The nano-imprint technique has been studied to apply it to a semiconductor process of forming a diffraction grating in a semiconductor laser. The manufacturing cost of devices such as semiconductor lasers can be reduced by forming the diffraction grating by the nano-imprint technique.
To form a diffraction grating in a semiconductor laser by the nano-imprint technique, first, a semiconductor layer on which the diffraction grating is to be formed and a resin part are formed on a semiconductor substrate in that order. Then, a mold having a pattern surface is pressed against the resin part. A pattern of the diffraction grating having periodic projections and recesses is formed on the pattern surface of the mold. Next, the resin part is hardened in that state. Subsequently, the mold and the resin part are detached from each other. Thus, the pattern of the diffraction grating formed on the pattern surface of the mold is transferred onto the resin part, so that a resin pattern portion is formed on the resin part.
Subsequently, the semiconductor layer is etched by using the resin pattern portion, so that the pattern formed in the resin pattern portion is transferred onto the semiconductor layer. Thus, the diffraction grating is formed on the semiconductor layer.
However, in the above-described method for manufacturing a diffraction grating by the nano-imprint technique, air may remain between the resin part and the recesses in the pattern surface of the mold when the pattern surface is pressed against the resin layer. Consequently, gas bubbles may become trapped between the resin part and the recesses in the pattern surface. If the resin part is hardened in such a state, the shape of the recesses in the mold cannot be appropriately transferred onto the resin part. As a result, defects are easily formed in the diffraction grating on the semiconductor layer.

Method for manufacturing semiconductor laser