An in situ plasma dry etching process for the formation of atomically sharp tips for use in high resolution microscopes in which i) a mask layer is deposited on a substrate, ii) a photoresist layer is patterned superjacent the mask layer at the sites where the tips are to be formed, iii) the mask is selectively removed by plasma etching, iv) after which the substrate is etched in the same plasma reacting chamber, thereby creating sharp microscope tips.

The present invention uses a substrate which, in the preferred embodiment includes a silicon layer. However, a deposited material, such as polysilicon or amorphous silicon, may also be used. Typically, these are semiconductor wafers, although it is possible to use other materials, such as silicon on sapphire (SOS) . Therefore, "wafers" is intended to refer to the substrate on which the inventive tips are formed.
High resolution microscopes play an important role in research by providing an image of objects previously imperceptible. The "scanning probe" microscopes are becoming more important in industry as such microscopes have several advantages over the scanning electron microscopes (SEM) presently used. Some of the advantages include: superior resolution, minimal sample damage, and the scanning probe microscopes provide quantitative, three-dimensional topographic data. The scanning tunneling microscope (STM), and atomic force microscope (AFM) are among the currently available high resolution probe scanning microscopes.
These high resolution microscopes function by means of a cantilever system. A very fine, sharp tip is disposed on one end of a soft cantilever spring on the other end of the cantilever is a mechanism for sensing the cantilever's deflection. A feedback loop monitors and controls the deflection. The microtip is used to scan a surface. A mechanical scanning system moves the surface with respect to the tip in a raster pattern. When the very fine tip encounters a microscopic bump in the surface, the sensing mechanism records the distortion, thereby producing an image of the surface as the surface is scanned on a display system that converts the measured data into an image.
Very fine, extremely sensitive tips are required for clarity in the high resolution microscopes. Current tips can have a radius less than 400.ANG., and are square-pyramidal in shape. The multiple contact points on the tip can result in atomic size images which show a complex superposition of effects.
Some of the present microscopes employ tips made of tungsten, which tips are further coated with a layer of silicon. One drawback with such tungsten tips is the difficulty in depositing the silicon in the desired thinness.
Other tips for scanning tunneling microscopes are disclosed in U.S. Pat. No. 4,985,627 entitled, "Spin-Polarized Scanning Tunneling Microscope," and U.S. Pat. No. 4,968,585 entitled, "Microfabricated Cantilever Stylus with Integrated Conical Tip; Semiconductor Integrated Circuit Fabrication Techniques for Tip for Scanning Tunneling Microscope."
In contrast to the prior art, tips fabricated by the process of the present invention are approximately 7.ANG.-10.ANG. at the apex. The process of the present invention employs dry etching (also referred to as plasma etching) to fabricate sharp tips. Plasma etching is the selective removal of material through the use of etching gases. It is a chemical process which uses plasma energy to drive the reaction. Those factors which control the precision of the etch are the temperature of the etchant, the time of immersion, and the composition of the gaseous etchant.
Various papers refer to reactive ion etching (RIE) and orientation dependent etching (ODE) of silicon to form tips. These technologies rely on either expensive multiple deposition and evaporation steps, or dry etch processes bound by the isotropic etching characteristics of the process gases. For example, prior art dry etch processes limit the manufacturer to a height to width etch ratio of 1:1. To alter this 1:1 ratio in order to obtain an increased depth, a deeper mask would be required.

Method of making atomically sharp tips useful in scanning probe microscopes


A printer includes a media stacking section, a print section, a pickup roller, a relay roller, a common actuator, a transport mechanism section and a control section. The control section is configured to control the common actuator based on a print job and displacement of the printing media. The control section is configured to stop transferring of driving force of the common actuator from the pickup roller to an nth printing medium after the pickup roller draws out the nth printing medium and the relay roller starts to send out the nth printing medium which is drawn out in a case where a print job, where printing is carried out on n of the printing media with a length in a transport direction shorter than a transport distance of the printing media from the pickup roller to the print section, is processed in the continuous transport mode.

1. Technical Field
The present invention relates to a printer and a printer control method.
2. Related Art
Printers in the prior art are provided with a pickup roller which draws out sheets which are stacked one sheet at a time and a relay roller which sends out the sheets which are drawn out by the pickup roller to a print section. The print section is provided with a sensor which detects the passing of an edge of the sheet, a transport roller which transports the sheet with the position of the edge of the sheet which is detected by the sensor as a reference, and a print head which carries out printing on the sheet which is transported by the transport roller. In recent years, printers which operate in a so-called continuous transport mode, where transporting of the succeeding sheet starts before printing on the preceding sheet is complete, are widespread and the time which is necessary to print a plurality of sheets is shortened (Japanese Unexamined Patent Application Publication No. 2009-155037).


Inventive concepts provide semiconductor memory devices and methods of fabricating the same. A stack structure and vertical channel structures are provided on a substrate. The stack structure includes insulating layers and gate electrodes alternately and repeatedly stacked on the substrate. The vertical channel structures penetrate the stack structure. Conductive pads are disposed on the vertical channel structures. An etch stopper covers sidewalls of the conductive pads. Pad contacts are disposed on the conductive pads to be in contact with the conductive pads. The pad contacts are further in contact with the etch stopper.

The inventive concepts relate to semiconductor memory devices and method of fabricating the same.
Semiconductor devices become more highly integrated to provide high performance semiconductor devices at low costs. The integration density of semiconductor memory device directly affects the costs of the semiconductor memory device, thereby resulting in more demands of highly-integrated semiconductor memory devices. The integration density of a conventional two-dimensional (2D) or planar semiconductor memory device is mainly determined by an area which a unit cell occupies. Therefore, the integration density of the conventional 2D semiconductor memory device is greatly affected by a technique of forming fine patterns. However, since the fine patterns are formed using extremely high-priced apparatuses, the integration intensity of the 2D semiconductor memory device continues to increase but still is limited. Thus, various researches are being conducted for a semiconductor memory device including memory cells that are vertically arranged.

Semiconductor memory device and method of fabricating the same


There is provided a high-density mask ROM operable at a high speed. With the mask ROM, respective source lines are disposed so as to be shared by memory cells in respective columns adjacent to each other, and bit lines are disposed so as to correspond to the respective columns of the memory cells. Further, the dummy cells are disposed for the respective columns of the memory cells. The dummy cells are each made up of a series-circuit including a first switching transistor that is turned into the conducting state in response to a signal potential on a dummy word line (DWL), and a second switching transistor 17 for coupling an adjacent source line to the bit line corresponding thereto in response to a potential of the source line in a column corresponding thereto. The memory cells each are made up of one unit of a transistor and a data storage formed by mask wiring. At the time of reading data, a potential of the source line in a select column is caused to undergo a change, whereupon there occurs a potential difference between a pair made up of the bit line as selected to which the memory cells as selected are coupled, and a reference bit line with the dummy cells coupled thereto, so that it is possible to execute readout of data by detecting the potential difference.

The invention relates to a nonvolatile semiconductor memory, and in particular, is concerned with a configuration of a mask ROM (Read Only Memory) wherein stored data is programmable by mask wiring.
With the mask ROM, data is fixedly stored by selectively forming metal interconnections in a storage with the use of a mask for a wiring pattern during a manufacturing process. The mask ROM includes a NAND type mask ROM, or a NOR type mask ROM, depending on a configuration of interconnection among memory cells. With the NAND type mask ROM, a plurality of memory cells are connected in series to each other between a bit line and a source line. Further, as is so often the case, data is stored by adjusting the threshold voltages of respective transistors of the memory cells through implantation of a dopant, thereby setting the respective transistors to an enhancement mode or a depletion mode.
With the NOR type mask ROM, one memory cell interconnects a bit line, and a source line. The one memory cell has a configuration wherein data is fixedly stored by selectively forming an interconnection between a transistor and the source line or the bit line by mask wiring, or a configuration wherein stored data is fixedly programmed by adjusting the threshold voltage of a memory cell transistor through implantation of a dopant, thereby setting the transistor to the enhancement mode or the depletion mode.
In the case of either the NAND type mask ROM, or the NOR type mask ROM, a word line is driven into a select state, and readout of data is executed according to magnitude of an electric current flowing between the bit line and the source line. That is, a select memory cell is disposed between the bit line and the source line, and the readout of the data is executed according to the magnitude of the electric current flowing between the bit line and the source line at the time when the word line corresponding thereto is selected. The bit lines are normally precharged to a predetermined voltage level, and readout of the data is executed according to magnitude of a change in bit line voltage, from a pre-charge voltage, at the time of selection of the memory cell. There have been proposed various configurations for the mask ROM in order to execute quick and stable readout of data.
With the NOR type mask ROM, use is normally made of a configuration of 1-cell/bit wherein 1-bit data is stored in one memory cell to meet demands for high-density while use is generally made of a configuration of 2-cells/bit wherein 1-bit data is stored in two memory cells to meet demands for high-speed.
Patent Document 1 (Japanese Unexamined Patent Publication No. Hei 9 (1997)-8255) has disclosed a configuration of a NAND type ROM wherein a distance between a source line and a ground line in a memory cell is kept constant regardless of a position of a select memory cell, inside a memory cell array, thereby attempting to achieve improvement on noise margin at the time of reading data. In Patent Document 1, as for a bit line in a select column, utilized as a source line for memory cells in an adjacent column, a memory cell current is caused to flow to a bit line in the adjacent column by a pre-charge current. Bit lines at symmetrical positions in the memory cell array are connected to dummy cells disposed outside the memory cell array, respectively, to thereby generate a reference current, and the memory cell current, and the reference current are subjected to differential amplification by a sense amplifier. With Patent Document 1, an attempt is made to keep source line resistance of the respective memory cells constant regardless of positions of the select columns, inside the memory cell array, by utilizing the bit line adjacent to a select bit line as the source line.
In Patent Document 2 (Japanese Unexamined Patent Publication No. 2001-203331), there is shown a ROM of a hierarchical bit line configuration, wherein a dummy cell is disposed at opposite ends of main bit lines in pairs, respectively, thereby differentially reading current changes of the main bit lines in pairs, respectively. With the adoption of the hierarchical bit line configuration, implementation of quick readout is attempted by reducing the number of memory cells connected to sub-bit lines, respectively, to accordingly reduce parasitic capacitances of the main/sub-bit lines, respectively. The dummy cells are each kept in the non-conducting state at all times, functioning as parasitic capacitance. A memory cell transistor is set to an enhancement mode or a depletion mode according to stored data, and data is read by differentially amplifying respective potentials of the main sub-bit lines, generated due to a current fed from a current supply source, flowing via a select memory cell, and respective potentials of reference main sub-bit lines.
In Patent Document 3 (Japanese Unexamined Patent Publication No. 2001-358235), there has been disclosed a ROM of a hierarchical bit line configuration, as with the case of Patent Document 2, wherein dummy cells connected to main bit lines are each made up of a MOS transistor (an insulated gate field effect transistor) with a source and a drain, mutually connected to each other. By so doing, parasitic capacitance of the dummy cell, for a bit line, is created by source junction capacitance and drain junction capacitance, and is rendered twice as large as parasitic capacitance of the memory cell, thereby reducing the number of the dummy cells in an attempt to attain higher density of the memory cells in a memory cell array.
In Patent Document 4 (Japanese Unexamined Patent Publication No. Hei 11 (1999)-191298), there has been disclosed a ROM of a hierarchical bit line configuration, wherein a sub-bit line is provided with a transistor for discharging in order to speed up readout of data, and the conducting state/non conducting state of the transistor for discharging is controlled by use of an inverting signal of a control signal for a block select gate transistor disposed between the sub-bit line, and a main bit line. With Patent Document 4, a read-cycle time is shortened by discharging the sub-bit lines at a higher speed, thereby attempting to speed up the readout of data. At the time of reading data, potentials of select main/sub-bit lines are differentially amplified with the use of unselect main/sub-bit lines serving as reference bit lines.
In Patent Document 5 (Japanese Unexamined Patent Publication No. Hei 7 (1995)-211086), there has been disclosed an array division structure for dividing a memory cell array into two arrays, wherein a word line driver is disposed between the arrays, a memory cell is selected in the array selected, and a memory cell current is detected by a sense amplifier while in the array unselected, a bit line is coupled to a sense amplifier corresponding thereto, and by the agency of an output signal thereof, timing for reading data is determined. A word line is in unselect state in the array unselected, and a bit line load remains constant regardless of stored data of the memory cell, so that a bit line charge speed becomes constant, which is utilized in this case.    [Patent Document 1] Japanese Unexamined Patent Publication No. Hei 9 (1997)-8255    [Patent Document 2] Japanese Unexamined Patent Publication No. 2001-203331    [Patent Document 3] Japanese Unexamined Patent Publication No. 2001-358235    [Patent Document 4] Japanese Unexamined Patent Publication No. Hei 11 (1999)-191298    [Patent Document 5] Japanese Unexamined Patent Publication No. Hei 7 (1995)-211086


A method of robust data broadcasting on a peripheral component interconnect(PCI) bus sets intended target agents to snoop the broadcast transaction in which the master agent also responds as the target agent.

The present invention relates generally to bus protocols and more specifically to a method for robust broadcasting on a Peripheral Component Interconnect(PCI) bus or the like.
Data broadcasting mechanisms are a proven and effective way to distribute data within high performance computing environments. The Peripheral Component Interconnect(PCI) bus is such an environment. PCI has become an industry standard low cost high performance bus architecture and is used in numerous computing environments.
A deficiency of the current PCI specification (Revision 2.1) is that it lacks a "robust" data broadcasting methodology. Generally, a robust data broadcasting methodology includes attributes such as explicit identification (e.g. addressing) of data packets, and high speed delivery of data packets with minimal delays and inefficiencies.
The PCI specification does implement a "simple" message broadcast mechanism via the Special Cycle transaction. The Special Cycle transaction can be used to communicate processor status or in general any logical sideband signaling required between PCI agents. PCI sideband signaling is defined as communication that occurs between two or more PCI agents that occurs outside the normal transfers supported by the PCI specification and only has meaning between those agents.
The Special Cycle transaction allows the PCI system designer a method of achieving sideband(even limited broadcast) communication without requiring additional signal pins. However, the Special Cycle transaction has several limitations. Some of the limitations are:
No explicit destination address(i.e. the address phase contains no valid information) PA1 The first data phase is required to be a 16 bit encoded message field and an optional 16 bit data field(i.e. useless fields) PA1 Only three message encodings are defined in the PCI specification, all other messages encodings are reserved. Additional message encodings must be obtained from the PCI Special Interest Group(SIG) Steering Committee. PA1 The Special Cycle transaction is required to be "slow" to allow target agents sufficient time to process the broadcasted request. The master agent is required to guarantee that the current access will not complete for at least four clocks after the last valid data phase. PA1 The standard mapping of the PCI bus' three physical address spaces(Memory, I/O, and Configuration) are available unaltered. PA1 In addition, some of the above unused PCI physical address space is allocated to master(s) and target(s) as the "master-self-responds-as-target, agents-set-to-snoop" physical address space to support the robust data broadcasting transaction of the invention.
As can be seen, the currently defined "simple" (i.e. Special Cycle) broadcast mechanism as defined per the PCI specification is not adequate to support the desired attributes for robust data broadcasting.
Computer systems requiring high speed data delivery would benefit by a method to allow a robust broadcast mechanism on a PCI bus without the need for additional sideband signaling pins.

Method and apparatus for robust data broadcast on a peripheral component interconnect bus


The present invention provides a fuel cell assembly comprising at least one fuel cell. The fuel cell comprises an anode, a cathode, and a electrolyte interposed therebetween; at least one fluid flow channel disposed within the fuel cell for delivering a fluid to the fuel cell and at least one array of flow disruptors in contact with at least one of the anode, the cathode and the electrolyte. The flow disruptors protrude into the fluid flow channel so as to disrupt a fluid flow and enhance a heat transfer rate between the fluid and the fuel cell assembly when the fluid is introduced into the fluid flow channel.

The present invention relates generally to power generation equipment such as fuel cells, and particularly to thermal management of fuel cells, for example, solid oxide fuel cells.
A fuel cell is an energy conversion device that produces electricity by electrochemically combining a fuel and an oxidant across an ionic conducting layer. A high temperature fuel cell bundle, for example, a solid oxide fuel cell bundle is typically constructed from flat single members having a planar configuration. The planar fuel cells can be of counter-flow, cross-flow and parallel flow varieties. The planar fuel cell typically comprises tri-layer anode/electrolyte/cathode components that conduct current from cell to cell and provide channels for gas flow into a cubic structure or stack.
Fuel cells, such as solid oxide fuel cells, have demonstrated potential for high efficiency and low pollution in power generation. However, problems associated with thermal management persist, particularly in regulating the temperature gradient of the fuel cell components. Thermal energy generated in the fuel cell from the reaction of the fuel and the oxidant needs to be removed or used internally in order to maintain the operating temperature in the fuel cell. Cooling channels in the fuel cells typically use an oxidant, such as air, to aid in the transfer or removal of waste heat from the fuel cell to the oxidant, so as to maintain a stack temperature at or below prescribed limits and maintain a predetermined thermal gradient. A temperature difference between a fuel cell assembly and a fluid, such as the oxidant, is a function of heat transfer characteristics of the fluid flowing through the fluid flow channel and a heat flux generated in the fuel cell assembly. However, such fluid flow channels, as used in conventional fuel cell applications, have a low convective thermal transfer coefficient between the fluid flow channel and the fluid flowing therethrough. Accordingly, there is a need in the art for a fuel cell having improved fluid passages that provide improved heat transfer characteristics.


A camera informs a user of a posture of a camera or availability of the detection and includes an image processing apparatus having a photographing part for taking an image, a posture detecting part for detecting the posture of the photographing part in taking the image, and a display part for displaying information for allowing the user to distinguish the posture detected by the posture detecting part together with the image to be taken by the photographing part.

1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method and a record medium having a program computer-readably recorded therein. In particular, the present invention relates to an image processing apparatus and an image processing method, which are capable of grasping in advance the posture of a taken image, and a record medium having a program computer readably recorded therein.
2. Related Background Art
Up to now, an image processing apparatus such as an electronic camera for recording and reproducing still images and moving images with a memory card having a solid-state memory element as a record medium has already been on the market. An electronic camera provided with an electronic finder, such as a color liquid crystal panel, has also been available on the market.
According to these electronic cameras, it is possible for users of the electronic cameras to continuously display images before taking the images and determine the compositions thereof or to reproduce and display taken images and confirm them. In particular, a function of reproducing taken images immediately after taking the images is highly convenient and is a useful function for users of the electronic cameras.
In addition, another electronic camera is also available which is provided with a posture detecting sensor or the like and distinguishes a posture of the camera to change a range for performing distance measurement and photometry according to the posture of the camera. Japanese Patent Application Laid-open No. 2000-312329 discloses an electronic camera that records postures of the camera together with taken images and rotates the images in accordance with a posture of the camera at the time of image taking to reproduce them.
However, such a conventional image processing apparatus, such as an electronic camera does not have a function for informing a user of the posture judged by the camera. In addition, an electronic camera, which records postures of the camera together with taken images and rotates the images in accordance with the posture of the camera at the time of image taking to reproduce them, does not have a function for informing a user of the direction in which a taken image is rotated and displayed at the time of reproduction.
Therefore, in order to enable a user to judge whether the posture determined by a camera coincides with a posture intended by the user, it is considered desirable to improve the camera such that the camera can display the determined posture.
In addition, in a camera incorporating a strobe or a camera having a strobe externally attached, if irradiation is necessary at the time of forced strobe emission or automatic strobe emission, illumination light irradiates a subject regardless of the vertical position and the horizontal position of the camera.
However, although there is no specific problem when the strobe is positioned above a photographing lens regardless of the posture (vertical and horizontal positions) of the camera at the time of image taking, an unnatural shadow is projected on a subject if illumination light irradiates the subject when the strobe is positioned under the photographing lens. For example, as shown in FIG. 20, if there is a wall 302 behind a subject 301, a shadow 303 of the subject 301 is unnaturally projected on the wall 302 behind the subject 301.
In addition, as described in Japanese Patent Application Laid-open No. 11-024150, if a gravity sensor is used as a posture detecting sensor, it is likely that the gravity sensor cannot perform correct posture detection if the elevation angle is equal to or larger than a predetermined angle (e.g., 70 degrees) in such a case where image taking is performed with a photographing lens oriented upward. Thus, an elevation angle sensor is provided in a camera to turn off the gravity sensor when the elevation angle is equal to or larger than the predetermined angle. In this case, positional information of the camera at the time of image taking cannot be recorded in images after taking the images. In addition, the camera does not have a function of informing a user that the camera is in an undetectable state at the time of image taking.
Therefore, if it is likely that a shadow of a subject is unnaturally projected at the time of image taking, it is considered desirable to improve a camera such that the camera can inform a user to that effect in advance. In addition, if a posture of the camera is undetectable, it is considered desirable to improve the camera such that the camera can inform a user to that effect.

Image processing apparatus and method for displaying an image and posture information


A vehicle washing apparatus includes a brush mounted to a drive shaft, a position locator for positioning the brush relative to a vehicle to be washed and a motor for rotating the drive shaft. A controller positions the brush proximate the vehicle for washing. A load sensor, for sensing the load on the drive shaft, is connected to the controller so that the controller may react to the sensed load exceeding a threshold by controlling a retraction of the brush from the vehicle. Additionally, parameters related to the operation of the brush may be determined based on information related to the size of the vehicle to be washed, where the size information is obtained by sensors.

Automated vehicle washing has a history reaching back several decades. In some cases the vehicle to be washed is driven or conveyed through a car wash structure or tunnel while being acted upon by washing elements. In other cases, the vehicle is stationary and the car wash structure includes washing elements that move relative to the vehicle while acting upon the vehicle. In any type of automated vehicle washing system, car wash structures often include washing elements designed to wash particular portions of the vehicles.
One known type of washing element is a cylindrical brush mounted on a shaft and/or hub that rotates about a generally horizontal and longitudinally oriented axis and is usually configured to brush the side surfaces of the vehicle. The horizontal and longitudinally mounted brushes may be arranged in a tunnel conveyor system along with various other brushes including transversely mounted roll-over brushes to clean the top of the vehicle and vertically mounted brushes to clean the front and rear portions. Water and soap are typically applied to the brush cleaning elements and/or to the surface of the vehicle to be cleaned to assist in the cleaning process. The brushes typically engage the generally vertically oriented and longitudinally extending side surfaces of the vehicle along with the generally outward facing surfaces of the wheels, tires and associated hubcaps of the vehicle. Such a brush may, during the course of the cleaning operation, engage a lower panel portion of a longitudinally extending side surface as the vehicle moves past the cylindrical brush.
Typically, two spaced and opposed, generally horizontally oriented and longitudinally extending cylindrical brushes may be employed for washing the lower portion and wheels of both the left (driver) and the right (passenger) sides of the vehicle. Additionally, these horizontal and longitudinally oriented, cylindrical brushes are mounted so that the transverse distance between the cylindrical brushes can be varied, to accommodate vehicles of various widths. The adjustment of the transverse positions of each of the opposed brushes may be provided by a position locator or apparatus (hereinafter referred to as a "position locator") controlled by a control device of some kind.
While the position locator has positioned a horizontal, rotating, usually cylindrical, brush proximate a vehicle so that the cleaning members of the cylindrical brush may contact and wash the side and wheels of the vehicle, the effectiveness of the washing may be, in part, related to the direction of rotation of the cylindrical brush and the proximity of the cylindrical brush axis to the vehicle side. It has been found that, when washing the driver's side of the vehicle, clockwise rotation of the cylindrical brush (as viewed from the front of the vehicle) provides more effective washing than counter-clockwise rotation of the cylindrical brush. (The opposite is true for the passenger side of the vehicle). This is because the brush members tend to engage the side with an upward motion, which it has been found is advantageous in removing dirt etc. from the surface of the side panel.
However, there are significant problems associated with rotating the brushes in this direction in that during the rotational movement of the cylindrical brush against the side of the car, and the relative upward motion of the individual cleaning elements relative to the side surface, friction between the cleaning members and the lower, rocker panel of the vehicle can tend to draw the cylindrical brush toward the under side of the vehicle. Additionally, it has been recognized that the cleaning members are quite likely to fairly consistently get caught on underside edges and other features that are on or proximate the underside of the vehicle when brushes rotate in this direction. This can cause the rotating brush to experience a significant increase in load and torque and can result in damage to the drive motor for the cylindrical brush.
Accordingly, horizontally and longitudinally oriented brushes adapted for cleaning the side surface of the vehicle are almost always rotated in the opposite direction (i.e., with relative downward motion of the cleaning elements against the side surface of the vehicle). This movement significantly reduces the aforesaid underside movement and catching problems, but impacts significantly upon the quality of the cleaning.
U.S. Pat. No. 4,691,401, issued Sep. 8, 1987 to Machin (hereinafter "Machin"), addresses a recognized problem wherein a vertical, rotating, cylindrical brush may, on occasion, catch in a convergent slot or gap formed by a vehicle bumper and a trailer hitch or coupler. In response to sensing an atypical event, such as, for example, a decrease in rotational motion of the brush, a change in brush orientation, a change in brush torque and/or a change in drive motor current, the rotation direction of the brush is reversed. This system however is not suitable for controlling a relatively continuous tendency of a horizontal, longitudinal brush to be dragged underneath the car resulting in the increasing torque and load on the brush.
One solution to the aforesaid problems in the horizontal and longitudinal oriented brush, is the split brush system, which employ two brushes configured in vertically stacked, side by side relation to each other and which have separate brushes rotating in opposite directions to each other. This solution is however somewhat unsatisfactory and also relatively expensive.


A hand-held material identification apparatus 10 uses a spectrograph and detector array detecting a Raman spectrum produced by a sample illuminated by a laser source to recognize a variety of materials with a command to recognition time cycle of about one second or less. The width of the spectrum detected by each detector in the array is less than xc2xcth the excitation source wavelength deviation to permit smoothing of the spectrum detected by the discrete spectral elements to eliminate pixel noise without loss of Raman spectral information. The Raman spectra are produced by materials illuminated by an inexpensive near-infrared multimode laser operated in a pulse mode to deliver between 0.05 and 0.5 joules of photon energy, with the Raman spectra being detected before any significant heating of the sample occurs. The identification apparatus 10 qualitatively determines the chemical composition of reinforced and unreinforced copolymers and composites such as ABS, polypropylene, talc-filled polypropylene, polycarbonate, PMMA, polyethylene, and PVC, from samples of different colors and textures with a high degree of success without the need for special positioning or sample preparation.

The present invention relates generally to applied optics, spectra-chemical image processing, chemical identification, and chemical analysis. More specifically, the present invention relates to apparatus and methods for the non-destructive testing and identification of the composition of a sample of plastics or other materials using Raman spectroscopy and computerized signal processing.
A widespread need exists in industry and government for identifying materials. For example, automobile companies and plastics manufactures must identify and separate plastic resins in recycling operations. Pharmaceutical companies must monitor chemical constituents during drug production. Monitoring agencies and firms must assay waste stream flows into the environment. Law enforcement agencies must identify the presence of illicit drugs in the field in order to combat criminal drug trafficking.
In today""s environmentally conscious society, simple economics provides a strong incentive for manufacturers to minimize their use of natural resources and public landfills. Substantial economic benefit can be gained by turning to recycling as a source for raw materials and as the ultimate repository for the manufactured goods. Using recycled raw materials in products can increase profits by saving materials costs and energy. Efficiently recycling packaging and production waste can save landfill charges and provide a cost recovery stream. Further, manufacturing goods with recycled content, and designing goods that themselves are recyclable, is a civic duty that also offers public relations benefits that are worthwhile from a marketing standpoint.
Many suppliers, however, face difficulties in using recycled feed streams. All companies face competition, and in the marketplace, price alone does not guarantee market share. Most manufacturers value quality and consistency of goods more than the abstract notions of civic duty and environmental policy. Further, many production lines operate with just-in-time inventories, in which a factory receives all the components necessary to assemble a product only hours before they are needed. The presence of only a few defective parts can shut down a production line until replacement parts arrive. Such a shut down can cost a manufacturer many thousands of dollars.
Thus, it is easy to understand why companies have been reluctant to include recycled materials in products. Recycled materials must have documented histories so that they are assured of compatibility with the manufacturing process. A misidentified piece of recycled material included with virgin material can destroy an entire production run. Maintaining the history of recycled goods, or even knowing their exact composition is difficult, if not impossible, with current technology.
Millions of tons of plastic and other materials are deposited in landfills or incinerated every year due almost solely to the lack of sufficient technology to avoid cross contamination between different types of plastic or other material during collection. The need therefore exists for an effective, economical means to identify a variety of materials, and-specifically plastics, on site in scrap yards, warehouses, factories and recycling centers. The successful commercialization of an instrument with such capabilities would greatly increase the recycling rates for plastics and perhaps many other materials. By offering a simple means to overcome the difficult problem of material identification, the present invention seeks to help make manufacturers more receptive to including recycled content in their products, and purchasers more confident of the quality of those products.
Many methods exist for identifying materials. One test for plastic materials, for example, involves the burning of a small sample of the plastic material. Upon smelling the smoke, a trained technician can identify several different classes of plastics with reasonable success. While this method can be employed in a laboratory, such methods are not appropriate or practical for commercial or production line applications. This type of chemical analysis would also not be acceptable to law enforcement personnel or the courts for the identification of Cocaine.
An assortment of analytical identification methods exist, such as Fourier Transform Infrared Spectroscopy (FTIR) and X-ray fluorescence (XRF), for the non-destructive testing of materials. An example of FTIR technology is disclosed in U.S. Pat. No. 5,510,619. While well known and used, the FTIR process is not practical in many commercial applications because the method is very sensitive to dirt, surface roughness, coatings, moisture, and sample motion during identification. The XRF process is also used but it is relatively expensive. Other analytical identification methods are disclosed, for example, in U.S. Pat. No. 5,256,880 and 5,512,752.
Raman spectroscopy, discovered by C. D. Raman in 1928, has many unique qualities that can be advantageously employed in the practical identification of materials. Raman signals, generated by the interaction of monochromatic light and a sample, are not affected by dirt, surface finish, coatings, or any motion of the sample being identified. Significantly, Raman signals are also not as sensitive to water, glass or quartz as other infrared signals. As a result, chemical samples can be contained within a glass vessel, or even suspended in an aqueous solution without affecting the Raman signal. The Raman process also has a significantly higher depth of field than other processes and can xe2x80x9clook throughxe2x80x9d a container to the chemical sample contained inside.
Despite these advantages, Raman spectroscopy is not widely used because of a low signal to noise ratio inherent in Raman Spectroscopy. Traditionally, the excitation light source, typically a laser, is directed continuously against a chemical sample, and the Raman signal is collected over time. An example of such an apparatus is disclosed in U.S. Pat. No. 5,534,997. Increasing the power of the excitation laser in the Raman process can increase the strength of the Raman signal and reduce the required sampling time. However, the increase in power can cause thermal damage to the sample particularly if the sample has low thermal conductivity that is typical of plastics. The increase in power can also cause xe2x80x9cblack bodyxe2x80x9d or thermal radiation that can overwhelm the Raman signal. It is commonly assumed, therefore, that Raman spectroscopy is not appropriate for the practical identification of highly energy absorbent materials such as black or highly pigmented plastics. In the extreme case, such highly absorbent materials can char or burn thus rendering the material unsuitable for further use.
What is needed is a system for analyzing and identifying the composition of a wide variety of materials that is fast enough for practical application in a commercial setting, insensitive to sample impurities or surface imperfections, tolerant of water and common sample containers, and which does not damage the sample being analyzed and identified.
A system satisfying these needs generally comprises a probe including a housing having an optical window through which visible and infrared light can pass. A monochromatic light source is provided with radiation optics optically coupling the light source to the optical window so that light emitted from the light source is directed through the window toward a sample causing the sample to produce a characteristic Raman signal. Sampling optics are coupled to the optical window to receive the characteristic Raman signal produced from the sample including at least one filter for removing unwanted spectral portions. A spectrograph is coupled to the sampling optics for dispersing the characteristic Raman signal into a spectrum to form a spectrographic output. An optical detector is coupled to the spectrograph to receive the spectrographic output and generate a digital map representing the Raman spectrum as a function of wavelength. A computer is coupled to the detector that includes an input to receive the digital map, a library of digital maps of specimens of known composition, a comparison means for comparing a received digital map with the contents of the library to select any match exceeding a specified confidence level, and an output display of the name of the selected match. A trigger circuit is included that initiates collection of the spectrographic output by the detector at the same time or slightly before it initiates emission by the light source so that data concerning the characteristic Raman signal from the sample can be collected by the detector before any significant heating of the sample can take place. The trigger circuit initiates selectively one or more pulses of light from the light source of specified duration and power so as to avoid or reduce the black body or thermal radiation problem commonly experienced with other apparatus. The apparatus is suitable for use to identify a wide variety of materials in gas, liquid, solid, or powder form, including polymers, plastics, ceramics, minerals, composites, pharmaceuticals, petrochemicals, organics, inorganics, biochemicals, and organo-metallics.
The present invention advantageously employs one or more discrete pulses of light, preferably generated by a laser, to cause the Raman signal to be produced by a sample. The monochromatic light source preferably comprises an inexpensive near-infrared multimode laser operable in a pulse mode between a lower and an upper intensity. The lower intensity level is at or just above the threshold intensity below which laser activity discontinues, typically less than about 105% of the lasing threshold. The upper intensity can be at any level at or below a maximum intensity established by the upper power limit of the laser. A xe2x80x9clapse timexe2x80x9d or xe2x80x9coff timexe2x80x9d between the laser pulses is provided to allow the sample to dissipate localized heat generated by the laser pulse. Advantageously, a single location on a sample can be exposed to more than one pulse during the sampling process, and allowed to cool between pulses. The laser pulses are cycled repeatedly until an adequate Raman signal is collected to allow the required analysis to identify the sample. The pulse width defining the duration of the upper intensity can be between about 0.01 and 10.0 seconds, depending upon the nature of the sample. In the preferred embodiment employing a 1.2 Watt laser, the pulse duration is between about 80 and 120 milliseconds for materials sensitive to optical damage. For less sensitive materials, a typical pulse duration can be up to about 500 milliseconds. The pulse duration can be shortened by using a correspondingly higher power laser to deliver between about 0.05 to 0.5 joules of photon energy to the sample. The number and duration of pulses employed to test a given sample is controlled to provide a satisfactory Raman signal while minimizing the thermal strain on the sample and avoiding detector saturation at any given pixel position. Shorter pulses and multiple discrete pulses are an important feature of the present invention which advantageously provides an enhanced Raman signal to noise ratio, even when considering sources of the same power, as the thermal noise and likelihood of detector saturation is kept to a minimum.
In a preferred embodiment of the invention, the probe housing includes a handle to permit manipulation of the probe, and further comprises a trigger situated on the handle and coupled to the light source so that depression of the trigger temporarily increases the output of light from the source, preferably in the form of one or more prescribed pulses as previously described. The apparatus preferably includes a console for housing the spectrograph, the optical detector, and the computer, and the sampling optics include a fiber-optic umbilical coupled between the console and the probe. The light source is housed in the console and the radiation optics includes at least one optical fiber carried by the fiber-optic umbilical. The probe housing preferably comprises an elongated rail having a lower and an upper surface, a longitudinal axis of the probe being separated by a fixed distance from the upper surface. A plurality of supports are fixed to the rail upper surface for supporting optical elements to intersect the longitudinal axis of the probe. The probe housing also includes a tubular member including a longitudinal slot that receives the rail so that an axis of revolution of the tubular member is coincident with the longitudinal axis of the probe and parallel to the rail upper surface. A back plate closes one end of the tubular member while a nose cone containing the optical window closes the other end. An off-axis baffling tube is supported by the rail parallel to the longitudinal axis to define a specific segregated region within the probe to permit extinction of unwanted portions of the light source spectrum immediately prior to illumination of the sample. This design allows for an ease of construction that contributes to lowering the cost of the overall system sufficiently to permit widespread adoption of the system by both industry and government.
In the preferred embodiment, the optical elements held by the plurality of supports within the probe can include lenses providing the probe with a prescribed depth of field, at least one filter, and a reflective element inclined with respect to the longitudinal axis of the probe for aligning the laser output with the optical window. To achieve optimum Raman signals, the lenses uniformly distribute the laser output over a sample irradiation area so as to achieve a power density of between about 1 mW/mm2 and 1 W/mm2. This is achieved by employing lenses having an f-number of between about 1 and 3. Preferably, the sampling optics includes a plurality of optical fibers, each of the fibers including an entrance end and an exit end. The entrance ends of the optical fibers are situated in a compact array in a common plane within the probe housing so as maximally to collect the Raman signal produced by the sample. The exit ends of the optical fibers are arranged in a line at an entrance to the spectrograph that typically contains a diffraction grating, the ruled surface of which is aligned to be parallel with the line defined by the exit ends of the optical fibers. This feature has the advantage of providing a signal to the spectrograph that is of enhanced intensity over that which might be gathered by a single fiber yet without diminishing the spectrographic resolution. The optical detector comprises an array detector having a number of outputs sufficient to define a division of the spectrographic output into a set of discrete spectral elements having a pixel width of about 0.2 nm.
A laser particularly suitable for use with the present invention is a near-infrared (NIR) multi-mode diode laser, the wavelength and deviation of which are compatible with spectrographic identification apparatus. The use of such a laser in the present invention provides an excitation source of lower cost yet higher power and reliability than comparable single-mode diode laser. In the preferred embodiment, the laser is a 1.2 Watt, 798 nm pulsed multi-mode laser excitation source having a wavelength deviation of less than 7 nm and more typically about 1-3 nm. The use of an excitation source having a wavelength deviation significantly greater than the pixel width in the spectrographic output achieves the surprising result of simplifying the smoothing the spectrum detected by the discrete spectral elements without loss of spectral information. This smoothing function is particularly important when derivatives of the spectrum are used for comparison as the difference in wavelength permits a significant reduction in pixel noise. The ratio of excitation source wavelength deviation to spectral detection element width is desirably between about 4 and 40, and preferably between about 5 and 20. That is, the width of the spectrum detected by each pixel of the detector is less than xc2xcth and preferably less than ⅕th the excitation source wavelength deviation.
In a typical embodiment of the present invention, the computer can be a general-purpose personal computer programmed to contain a library of digital maps of various materials of known composition. In the preferred embodiment, the digital maps consist of a second-derivative vector of the spectrographic output as a function of Raman shift wavelength smoothed to exclude the short wavelength pixel noise. The resulting second derivative is treated as an n-dimensional vector where n is the number of pixels in the spectrographic output. The computer is programmed to compare the information taken from a sample of unknown composition with the library by computing a vector dot product of the vector of the sample with each specimen vector stored in the library. The dot product constitutes a scalar evaluation of coincidence between each pair of vectors. Based on this computation, the computer can be programmed to select the best fit by merely retaining the identity of the known material having the highest value for the dot product, and displaying that identity. Where the library contains vectors of a number of very closely related materials, the computer can be programmed to retain all library-stored vectors for which the vector dot product was greater than a specified value. The computer can then conduct a review of additional criteria of the sample vector that could discriminate the retained library vectors to select the best fit. This feature, when employed by even conventional personal computers having operating speeds in the order of 300 MHz, provides an accurate identification of a wide variety of materials, typically in only 1 or 2 seconds. Where very rapid sample identification in desired, for example in automated systems, dedicated digital signal processing equipment can be employed rather than general purpose personal computers.
By offering a simple means to overcome the difficult problem of identification of materials for recycling, the present invention seeks to help make manufacturers more receptive to the idea of including recycled content in their products and give purchasers more confidence in the quality of those products. The same system programmed with a slightly different library of reference materials can enable companies to monitor a wide variety chemical constituents during manufacture and permit the assay waste stream flows into the environment for any unwanted contamination. Law enforcement agencies are also able to use the system to identify the presence of illicit drugs in the field without affecting the chemical make-up of the sample or detracting from the amount of material tested.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.

Raman system for rapid sample indentification


A power steering control valve including relatively rotatable inner and outer valve members. A power steering resistance control system resists relative rotation between the inner and outer valve members with a force which varies as a function of variations in vehicle speed. The power steering resistance control system includes a force transmitting member which is disposed adjacent to one end of an outer valve member. A spring force is applied against the force transmitting member urging it in a first direction along the axis of rotation of the valve member. Fluid pressure is applied against the force transmitting member to urge it in the first direction. A speed responsive control unit is operable to vary the fluid pressure applied against the force transmitting member as a function of variations in vehicle speed. The power steering resistance control system also includes a means for preventing an increase in the resistance to relative movement between the valve members as the vehicle speed increases when there is no relative movement between the valve members.

The present invention relates to a vehicle power steering system, and more specifically to a hydraulic vehicle power steering system in which the resistance to actuation of a power steering control valve increases with increasing vehicle speed.
A known rotary power steering control valve shown in U.S. Pat. No. 5,046,574 has an inner valve member which is coaxial with and rotatable relative to an outer valve member or sleeve. To effect actuation of the power steering motor to turn steerable vehicle wheels, the inner valve member is rotated relative to the outer valve member. A fluid pressure reaction chamber is provided to regulate the torque required to rotate the inner valve member relative to the outer valve member. The fluid pressure in the reaction chamber increases as vehicle speed increases to increase the resistance felt by an operator of the vehicle to rotation of the inner valve member relative to the outer valve member.
In U.S. Pat. No. 5,046,574 the fluid pressure in the reaction chamber is independent of vehicle steering activity. Hence, a power steering pump has to act continuously against an increasing pressure as vehicle speed increases. Thus, there is a loss of horsepower and heat generated due to the pump acting against the relatively high pressure at high vehicle speeds when there is no steering activity.


Belt for use in a continuous variable transmission, comprising an endless carrier for taking op tensile forces, and a plurality of transverse elements moveable in the longitudinal direction along the carrier. The elements are provided with at least one saddle surface for contacting the carrier. The saddle surface defines an ultimate mutual position of the carrier and the elements relative to each other within the belt in radial direction, with a tapered lower element part including a rocking edge and an upper part extending radially beyond the carrier, when the carrier and surface are in mutual contact. Each axial end of the surface is adjoined by a limb extending predominantly in radial outward direction, thereby defining a recess open to the radial outer end of the element allowing free insertion of the carrier in the recess.

The present invention principally, but not exclusively, aims at realising a single package belt design without above mentioned cost raising disadvantages, which is composed of only a single element type, which has a relatively uncomplicated shape and a relatively low weight so as to maximise the amount of torque transmittable by the belt.
In this design the limbs are released of a hooking function, i.e. released from a function in aiding the elements to exit a pulley. In the known belt design this function implicate, taken in longitudinal view, an axial outward moment acting at the base, i.e. radially innermost part of a limb, which thus is required to be relatively broad. Presumably to reduce the weight of the element, in the known design the limbs have been cut off in axial width toward their radial outer end. In the current invention, in the absence of such function the limbs may be made of substantial less axial width, allowing the m to extend fully radially beyond the carrier. This is realised by allowing a free, i.e. unforced mutual insertion of element and carrier. Surprisingly departing from the underlying insight according to the invention that at an in between pulleys trajectory the belt may be trusted to assume an at least slightly radially inwardly curved shape by mutual contacting of the radial outer portions of the elements, whereby exiting of the pulley is effect by the elements mutually contacting.
A major advantage in the current design, apart from ease of assembly, is realised in that the power transmitting capacity is optimised by the reduction on overall limb width, particularly in relation to the nominal element width, implying the width of the element at the rocking edge, which is generally proportional to an axial width of the carrier. The measure according to the invention allows the saddle surface to be relatively increased, which is favourable since thereby the width of the carrier may be increased and accordingly its thickness reduced. This is particularly advantageous when the carrier is composed of a set of radially stacked endless rings. It being recognised by the invention that radial outer rings of such set tends to contribute less to the power transmitting capacity than the radial inner rings. A reduction in number of rings may then be favoured over a small increase in the axial width of the carrier. Moreover, the number of rings also has a large influence on cost. Particularly, in this respect, the width of the individual limbs at a level at or near the saddle surface is set at less than one-twelfth the axial width of said surface.
In a further development of the invention, the limbs are directed at least for a predominant part radially under an angle at least substantially conforming to the angle at which lateral side faces, or pulley contact faces, of the elements for contacting the sheaves of a pulley are oriented, i.e. so-called flank angle cone angle. In this manner an axially wide mutual-contacting basis is realised for the elements, promoting the stability of the belt current design. Such is particularly desired in view of a lack of mutual hooking function of elements and carrier.
In yet a further development of the invention, the limbs of the elements may be provided with a hooking portion as known per se. However, according to the invention it is provided at considerably beyond the carrier when in contact with the element, such that it may be introduced by mutual rotation about the longitudinal direction of the belt. By this measure a stable mutual contacting of the element's upper parts, both in a pushing and in a slack in between pulleys trajectory is realised, enhancing both a secure operation of the belt, and the torque transmitting capacity thereof. Again this support the limb design according to the invention having a small axial width favouring the axial width of the saddle surface. The measure according to the invention of realising a large width of the limb at some radial distance from the carrier favours good mutual contact of the elements upper parts. With such a design, most secure with the longitudinal play between the elements of the belt reduced to a minimum in conformance with the common practice in the known belts, the belt operates in a manner wherein mutual contacting of the element upper parts prevent the belt from disintegrating.
The present invention further aims at principally realising a single package belt design without above mentioned cost raising disadvantages, which is composed of the least possible number of element types, which has a relatively uncomplicated shape and a relatively low weight so as to maximise an amount of torque transmittable by the belt, while still responding in a good manner to the various functional demands for a belt. Such a belt is according to the invention realised by the feature of the limbs extending radially beyond the carrier, defining a recess open to the radial outer side of the element, allowing a free mutual insertion between the element and the carrier.
A belt comprising such features may be produced easily since no additional part is required as a retaining means. Surprisingly in the design according to the invention, the retaining means is achieved by favourably utilising and adapting some geometric features inherently present within a belt, being the adaptation of the ratio between a belt's total longitudinal play between its elements and the radial belt height above the rocking edge. The solution is based on the insight that at a slack in between pulleys portion of the belt, the most critical part in view of disintegration of the belt, the elements may block one another in a stable end position in which the relevant belt part is curved at least slightly concave. The solution takes account of the experience and insight that such slack part tends to buckle radial inward due to the clamping action at the pulley where the belt exits, which makes the belt, at least the elements thereof to tend to continue to rotate with the same pulley.
With the solution according to the invention favourably large values of longitudinal play between adjacent pairs of element within the belt may be allowed thus favouring the assembly of the belt when the element height above the rocking edge is made sufficiently large. The invention hereby may take advantage of the experience that only part of the said is present in the slack trajectory part, while moreover the portion of that play actually present in this slack trajectory tends to be distributed between pairs of adjacent elements.
Alternatively to the preceding solution, the described problem of maintaining the integrity of a so called single package belt is according to the invention solved by a feature which is here incorporated in addition to the preceding solution. In this feature, at least the majority of the transverse elements have a upper element part of which a radial outer end portion has a greater thickness than that of the said rocking edge, such that an array of elements pushed against one another with in said belt by mutually contacting with said end portions, assumes a stable arc-like shape. In this manner, at least at a pushing in between pulley's trajectory a so called cat's back-like. arc is achieved in the pushing part of a belt as arranged between two pulleys. Thus exiting of a belt from a pulley is enhanced, while the elements do not fall apart from each other or from the carrier since they are wedged in their position when observed, from side elevation. With the addition, or presence as the case may be, of such feature, the belt may at stand still of a transmission be incorporated without the presence of a pre-tensioning spring in a pulley, since the wedging feature prevents the elements located at a transmissions upper side with respect to the earth's gravity from assuming a position from which the belt may no longer deform to a desired rod like condition. In a slack trajectory part either at the transmissions upper or lower side, the wedging feature aids in assuming a stable inwardly curved end position of the slack trajectory.
Surprisingly the measure according to the latter aspect of invention again realises the integrity of the belt while obviating to application of the previously described known means for maintaining the integrity of the belt by positively or directly limiting the relative radial movement between the transverse element and the carrier. This provides for the possibility of applying a recess entirely open in radial direction, i.e. with even leaving away hook or locking parts. For achieving this effect, according to the invention only a small but noticeable amount of tapering of the upper element part is required. In this way favourable advantage is taken of the circumstance that a belt incorporates a significantly large number of transverse elements.
It is here remarked that in the context of the current description the height of the element is assumed to concur with the dimension of the belt in the radial direction when positioned in a circular shape, the width of the element concurs with the dimension of the belt in the transverse or axial direction and the thickness of the element concurs to its dimension in the belt's longitudinal direction, i.e. along the circumference of the belt.
The above proposed embodiments and aspects of the invention, either per se or in combination most favourably operate in combination with a carrier composed of a set of radially nested endless flat metal bands that are relatively thin.


The heterodyne receiver includes an antenna, a local oscillator, a mixer mixing a signal received by the antenna with a local oscillation signal generated by the local oscillator to produce an IF signal, and a demodulator demodulating the IF signal. The local oscillator is configured to set a frequency of the local oscillation signal at such a frequency that a frequency of the IF signal becomes a predetermined intermediate frequency when any one of intended signals having frequencies within a predetermined frequency range is being received by the antenna, and to fix the frequency of the local oscillation signal at a predetermined oscillation frequency when any one of the intended signals is not being received by the antenna.

1. Field of the Invention
The present invention relates to a heterodyne receiver, and a communication system using the heterodyne receiver.
2. Description of Related Art
Heterodyne receivers having a downconverter for downconverting a received radio signal (may be referred to as high frequency signal hereinafter) to an IF (Intermediate Frequency) signal before demodulating this received high-frequency signal are widely used.
FIG. 5 shows a structure of a common heterodyne receiver. This heterodyne receiver includes an antenna 101, a bandpass filter 102, a low noise amplifier 103, a local oscillator 104, a mixer 105, a bandpass filter 106, and a demodulator 107.
A radio signal received by the antenna 101 is band-limited by the bandpass filter 102, and then amplified by the amplifier 103. The signal amplified by the amplifier 103 is mixed with (or multiplied by) a local oscillation signal having a fixed frequency outputted from the local oscillator 104 to be downconverted into an IF signal. The IF signal is band-limited by the bandpass filter 106, and then demodulated by the demodulator 107 to produce demodulated data.
When the frequency of a radio signal intended to be received and demodulated is F1, and the frequency of the local oscillation signal generated by the local oscillator 104 is F2, the frequency F3 of the downconverted IF signal becomes F1−F2. Accordingly, in a case where F1 is 315 MHz and F3 is set at 10.7 MHz, it is necessary for the local oscillator 104 to generate an oscillation signal having a frequency of F2=F1−F3=304.3 MHz. The local oscillator 104 can generate the 304.3 MHz oscillation signal through about 5 times frequency multiplication on a 60 MHz oscillation signal obtained by use of quartz, for example.
It is also known to constitute such a local oscillator by a PLL circuit as described, for example, in Japanese Patent Application Laid-open No. 2000-286738.
Incidentally, vehicles are becoming equipped with different in-vehicle wireless systems such as the tire pressure monitoring system, remote key entry system and smart key system. Accordingly, it is becoming necessary to mount different receives corresponding to these different systems on each vehicle, because these systems use different frequencies.

Heterodyne receiver and communication system with demodulator switchable between demodulation schemes based on received status signal


A transportable photovoltaic system includes a plurality of photovoltaic devices, a composite frame to which the plurality of photovoltaic devices are affixed, and a base structure to which the composite frame is movably attached through at least one variable-angle mount structure. The orientation of the frame and the light concentrating elements relative to the base structure can be altered employing the at least one variable-angle mount structure. The frame and the plurality of photovoltaic devices can be assembled prior to shipping, and the base structure can be manufactured on site. The transportable photovoltaic system is not affixed to ground or other fixture, but can be picked up at any time during the operational lifetime. The transportable photovoltaic system can be rapidly deployed with little or no site preparation requirement other than generally level ground, and can be retracted to a lower exposure position to avoid storm and/or hazardous conditions.

The present disclosure relates to solar concentrators, and more particularly to a transportable photovoltaic system configured for rapid deployment and methods of operating the same.
Solar concentrators allow replacement of large quantities of expensive semiconductor materials used in fixed flat panel systems with less expensive materials so that light can be concentrated on a smaller high power semiconductor photovoltaic device to achieve comparable performance at a lower cost. Varieties of solar concentrator photovoltaic systems have been constructed and deployed that range from small rooftop systems producing a few watts to very large concentrators producing thousands of watts of power.
Once deployed, the solar concentrator photovoltaic systems must tolerate exposure to temperature extremes, dust, rain, hail and high winds. The ability to tolerate gusts of 140 miles per hour is a common requirement. Power inversion from direct current (DC) to alternating current (AC) is typically performed by connecting many concentrators systems into a single inverter operating at up to many thousands of watts. In more recent embodiments, micro inverters have been introduced that will grid couple smaller solar collectors operating at powers of 100 W to 500 W.
A significant cost component in many current systems is the cost for on site assembly and extensive site preparation. Concentrator systems are constructed in component form and shipped to the site for assembly. On site preparation includes grading, excavation and pouring of foundations. Once a solar concentrator photovoltaic system is constructed at a location, the solar concentrator photovoltaic system remains at that location throughout the duration of the lifetime of the solar concentrator photovoltaic system.

This patent is subject to a terminal disclaimer.

INTERNATIONAL BUSINESS MACHINES CORPORATION


A micro-sized power source. A piezoelectric power generator, capable of harvesting energy from environmental vibration with lower level frequency, including a dielectric frame loosely containing a piezoelectric panel. The piezoelectric panel includes an electrode and a piezoelectric layer formed over an electrode and dielectric layer and an end mass formed on the piezoelectric layer. The end mass provides weight to cause the piezoelectric panel to move (vibrate) within the frame and causes the generation of electrical power.

Wireless sensor networks provide promising solutions for broad areas of use ranging from building monitoring to medical implants applications. Wireless sensors provide advantages during wide use of cost savings, installation simplicity, remote control, etc. The problem associated with the concept of a wireless network, however, lies with determining how to supply power to contactless, embedded sensors.
Batteries are automatically thought to be a solution for providing power to remote device, but such power sources are limited by their finite lifetime. In addition, sensor nodes tend to be portable and integrated with multi-functions, therefore, limited power issues, small size and integration capabilities pose additional problems in front of the effective implementation of a promising wireless sensor network.
The present inventor believes what are needed are solutions for scavenging energy from the environment, eliminating the need of batteries and extending a device's operating lifetime infinitely. Advances in low power VLSI design, along with the low duty cycles of miniaturized wireless sensors have reduced power requirements to the range of microwatts. In such range of consumption, power supplied by energy harvesting could be a viable alternative. Possible energy sources for use with systems in the micro-domain include solar, thermal, mechanical, human body and wind.
With advances in MEMS technology, the present inventor believes it is now possible to implement a self-powered system together with MEMS devices acting as an electromechanical transducer with conversion governed by employing low power digital control techniques, while keeping the whole system in a small-sized package. Therefore, what is required is a system, apparatus, and/or method that provides an improved power source that overcomes at least some of the limitations of previous systems and/or methods.

Micromachined, piezoelectric vibration-induced energy harvesting device and its fabrication


A method of forming a sub-lithographic charge storage element on a semiconductor substrate is provided. The method can involve providing first and second layers on a semiconductor substrate, a thickness of the first layer being larger than a thickness of the second layer; forming a spacer adjacent a side surface of the first layer and on a portion of an upper surface of the second layer; and removing an exposed portion of the second layer that is not covered by the spacer. By removing the exposed portion of the second layer while leaving a portion of the second layer that is protected by the spacer, the method can make a sub-lithographic charge storage element from the remaining portion of the second layer on the semiconductor substrate.

In the semiconductor industry, there is a continuing trend toward higher device densities. To achieve these high densities there have been, and continue to be, efforts toward scaling down device dimensions (e.g., at sub-micron levels) on semiconductor wafers and to increase the number of layers of such devices on a chip. In order to accomplish such high device packing densities, smaller and smaller features sizes are required. This may include the width and spacing of interconnecting lines, spacing and diameter of contact holes, and the surface geometry, such as corners and edges, of various features.
The process of manufacturing semiconductors, or integrated circuits (commonly called ICs, or chips), typically consists of more than a hundred steps, during which hundreds of copies of an integrated circuit may be formed on a single wafer. Generally, the process involves creating several patterned layers on and into the substrate that ultimately forms the complete integrated circuit. This layering process creates electrically active regions in and on the semiconductor wafer surface.
The requirement of small features with close spacing between adjacent features requires sophisticated manufacturing techniques including dielectric layer deposition and planarization of the dielectric layer. Fabricating a semiconductor structure using such sophisticated techniques may involve a series of steps including cleaning, thermal oxidation or deposition, masking, developing, etching, baking and doping.

Self aligned narrow storage elements for advanced memory device


A security element in the form of a thread or strip to be embedded in security documents such as bank notes, checks, bonds, identity cards, credit cards or the like, having characters, patterns, etc., that are readable by transmitted light to the naked eye and/or by machine. The security element consists of a transparent plastic film having an opaque coating extending over the element with recesses in the form of the characters and patterns to be introduced. The security element also contains, in areas congruent with the recesses, coloring and/or luminescent substances which cause the characters and/or patterns to differ from the security document and from the opaque coating by color contrast under suitable light conditions.

1. Field of the Invention
The present invention relates to a security element in the form of a tread or strip to be embedded in security documents such as bank notes, checks, bonds or the like, having characters, patterns, etc., that are readable by transmitted light to the naked eye and/or by machine, and to methods of producing such security documents.
2. Description of the Related Technology
It has been known for some time to protect bank notes and other money-value papers such as cheeks, shares, travelers checks, check cards and credit cards, but also passports and identity cards, by adding so-called security threads. Papers of this kind shall be referred to in the following as security papers. The security threads used for this purpose are made of a great variety of materials in the form of fine strips which are added in widths of 0.4 to 2 mm to the paper sheet during its manufacture. They are primarily produced from plastic films coated with metal foils, printed, colored or provided e.g. with pigmentlike substances. Furthermore, it is also known to give these security threads magnetic, fluorescent, X-ray absorbent and other properties by applying appropriate substances.
It has proven particularly advantageous to use security threads with microprints, whereby this microprint may contain information that is readable by the naked eye or else only by machine.
With respect to protection from forgery, security threads with metallically reflecting surfaces have proven particularly useful, since such threads introduced inside the paper are almost invisible by incident light, as the light rays passing through the upper layer of paper are completely reflected by the metallic surface and leave the paper diffusely scattered. By transmitted light, however, such threads appear as black strips which are clearly distinct from their surroundings. Threads of this kind cannot be imitated by printing on the paper. On the other hand, they show the disadvantage that a corresponding impression can be incorrectly aroused by introducing thin aluminum foils between two layers of paper. It has therefore been proposed to provide such aluminized security threads with microwriting (German laid open print no. 14 46 851). However, this has proven to be of little use in practice since this writing cannot be detected on the otherwise opaque security thread by transmitted light, and can only be detected with great difficulty by incident light. It is usually necessary to make the paper transparent with chemical means at least for the time of testing. The execution of such microwriting in special, e.g. fluorescent, colors has proven to be of little advantage in the same way and for the same reasons.
German "Auslegeschrift" no. 22 05 428 discloses a security thread designed as a metal strip and having a machine readable and/or visually readable coding applied by laser. The writing on this thread, that may possibly contain alphanumeric characters, consists of perforations, whereby the diameter of the holes or "line width" is to be small compared to the thickness of the metal strip in order to impede imitation.
Due to their extremely small line width, the characters of this security thread are detectable as poorly visible lighter areas on the dark background. Furthermore, such writing is relatively troublesome to produce, since very powerful lasers are required to provide the perforations in the metal thread. The perforation of the security thread material is so time-consuming that this method cannot be used for producing large amounts (thousands of kilometers) simply for reasons of time and thus of costs.
U.S. Pat. No. 4,652,015 also discloses a security thread to be used for bank notes and the like, on which metallically shining microcharacters are provided on clear transparent film material. The security thread and microcharacters located thereon as described in this patent are not detectable by incident light. However, by transmitted light solely the characters are detectable as sharp contours since the security thread itself is of transparent design. This security thread is produced by metalizing a transparent film over a large surface with a thin aluminum layer, printing the microcharacters on this layer using an acidproof ink and then etching away the unprinted areas, whereupon the characters are left on a transparent base.
By transmitted light an observer thus sees only writing that runs through the bank note. However, a disadvantage is that this writing is difficult to find due to the small size of the characters, its embedding in the paper pulp and a printed pattern that may be superimposed. The thread as such cannot be detected by the naked eye and cannot be felt as an uneven formation on the surface of the paper due to the extremely thin design required here. These detection features that normally characterize a security thread are thus no longer present in the known thread.

Security element in the form of a thread or strip to be embedded in security documents and methods of producing it

GAO Gessellschaft fur Automation und Organisation GmbH


A flat wide-angle lens system of the invention has a reduced axial length and is intended for creating images with extremely wide angle of observation. The system consists of the first component which is intended for reduction of the field angle of light incidence onto the objective and comprises an assembly of at least two microlens arrays with the same pitch between the adjacent microlenses and arranged with respect to each other so as to provide afocality, and a second component that comprises an assembly of conventional spherical or aspherical microlenses that create an image on an image receiver. Each two coaxial microlenses of the microlens arrays of the first component form an inverted microtelescope of Galileo. The outlet aperture of a single microtelescope is made so that spherical aberration can be minimized almost to 0, while field aberrations can be corrected by design parameters of the microlenses.

For better understanding the terminology used in the present description and principles of structure of optical systems in general, it would be advantageous to make some short introduction into the field of optical objectives.
An objective is an optical system or a part thereof that faces an object of observation or photographing and that creates a real image of the object turned 180° with respect to the object. Depending on the types of optical elements, objectives can be divided into lens-types, mirror-types, mirror-lens-types, and kinoform-type objectives. Most popular are lens-type objectives that are capable of acquiring various characteristics due to increase in the number of component lenses.
Photographic objectives or similar objectives of motion-picture cameras, TV cameras, night-vision instruments, and objectives used in television generally create reduced images of remote objects on a layer of a photosensitive material or on photoreceivers, e.g., TV picture tubes, matrices or linear photoreceivers, or photocathodes of optoelectronic devices. The scale of an image is proportional to a focal distance f′ of the objective, while illumination intensity is inversely proportional to a second power of a diaphragm number K, which is an f′/D ratio where D is a diaphragm of an inlet pupil of the objective. A value of 1/K is known as an aperture ratio. The limit value of the diaphragm number that allows correction of aberrations is K=0.5. A majority of existing objectives have K within the range of 3>K≧1.2. Photographic resolution capacity Nf of photo and motion-picture objectives depends on aberrations, as well as on resolution capacity Nc of the photosensitive layer of the reproducing medium and can be calculated with the use of the following approximated formula: 1/Nf=1/N0+1/Nc, wherein N0 is a visual resolution capacity of the objective. In a lens system, aberration is an error resulting from a failure of light rays from one point to converge to a single focus. A part of a space or surface the points of which are reproduced by the objective with a required quality is characterized by an angular field, i.e., a flat angle 2ω that corresponds to a solid angle that is coaxial with the optical axis and has the apex in the center of the inlet pupil of the objective. Angular field of modern photo cameras is normally within the range of 40° to 70°, while in aerophoto cameras this angle may reach 140°.
A special group is pancreatic objectives which are also known as zoom lenses, the focal distance of which can be smoothly adjusted in a wide range by displacing separate lenses or groups of lenses along their optical axis. The number of lenses in such objectives may be as high as 30 or more. Such objectives are used, e.g., in transmission TV cameras, video cameras, and photo cameras. A ratio between the maximal and minimal focus distances may reach 40, or more. For decrease of optical losses, modern objectives are provided with anti-reflective coatings.
Normally, conventional wide-angle photographic objectives or lens systems have big dimensions, i.e., a lengthy objective, and therefore are inconvenient for use and storage. Another characteristic feature of a wide-angle photographic lens system is an increased diameter. This not only increases the overall radius and hence the dimensions of the lens system but also significantly increases the weight of the objective as a whole.
There exist a large number of wide-angle photographic lens systems of different types, e.g., conventional photographic lens systems for photocameras, image projecting lens systems, wide-field lithography systems, etc.
For example, U.S. Pat. No. 4,188,092 issued in 1980 to Kikuo Momiyama describes a retrofocus type lens for a photocamera having an angle of view at least 75° and F number 1:2.0. The lens includes a first lens group of a divergent type, a second lens group of a convergent type, and a third lens group of a convergent type. The first lens group includes in the order stated a positive meniscus lens, a negative meniscus lens, a positive meniscus lens, and a negative meniscus lens. The second lens group includes a positive lens, which is either a single lens or consists of a positive lens, and a negative lens cemented to each other and with a front convex face directed toward an object to be photographed. The third lens group includes a positive lens having a rear convex face directed toward an image of the object, a biconcave lens with its front surface radius smaller than its rear surface radius, a positive meniscus lens with a convex surface facing the image, and a positive lens. The biconcave lens and the positive meniscus lens are respectively replaceable with cemented doublet lenses. The lens system is characterized in that the first lens group includes meniscus lenses arranged in the order of positive, negative, positive and negative lenses, and particularly in that the third positive meniscus lens serves effectively to correct chromatic distortion aberration and chromatic coma aberration.
Another example, e.g., U.S. Pat. No. 6,084,719 issued in 2000 to Saburo Saguwara, et al. discloses a projection optical system that includes a first lens unit in which negative lenses included therein are larger in number than positive lenses included therein, and a second lens unit in which positive lenses included therein are larger in number than negative lenses included therein. In this projection system, design parameters are determined such that an off-axial principal ray intersects an optical axis at a point between the first lens unit and the second lens unit, and telecentricity is made on the second conjugate point side. The second lens unit includes a negative lens of meniscus form convex toward the second conjugate point side and a positive lens whose both surfaces are convex.
A common problem associated with wide-angle lens systems of the types described above as well as with other conventional wide-angle lens systems is that an increase in the aperture ratio of the lens system, widening of the field of observation, and improvement in resolution capacity of the optical system require an increase in the lens diameter. However, such an increase leads to more noticeable aberrations, and in order to solve the aberration problem, it is necessary to introduce into the system new optical elements. However, Increasing the number of lens elements to overcome the above-described drawbacks degrades the performance of the lens system due to adverse effects such as flare. All this significantly increases the manufacturing cost and the cost of the products.
Attempts have been made, however, to solve the above problems and to improve conventional wide-angle lens systems, e.g., by increasing the amount of optical elements.
For example, U.S. Pat. No. 5,790,324 issued in 1998 to Cheon-Ho Park describes a wide-angle photographic lens system in which improvement in optical characteristics is achieved at the expense of complexity, increased weight, and increased cost. More specifically, the aforementioned lens system consists of seven lens elements, including combined lens elements.
One of the latest patents in this field, i.e., U.S. Pat. No. 6,545,824 issued in 2003 to Sensui Takayuki, discloses a significantly improved lens optical system, in which the number of lens elements is reduced to five along with a twice shorter length of the system as a whole. Nevertheless, while preserving the traditional structure, the lens optical system of U.S. Pat. No. 6,545,82 still remains large in size, heavy in weight, and complicated in structure. These problems will always remain until a wide-angle lens system is designed on traditional principles of a wide-lens system architecture.
Development of optical fiber systems, light-emitting diodes and laser diodes, systems of management, control, and conversion of light beams in optical communication systems, etc. gave impetus to developing new and efficient microoptical systems such as microlenses, microobjectives, collimators, etc. In principle of their operation and structure, the aforementioned optical elements are the same as respective traditional optical lenses, objective, collimators, etc., but are intended for working with optical beams of small diameters, e.g., from several tens of microns to several millimeters. Miniaturization of optical elements to the level of current microlenses led to very stringent requirements with regard to manufacturing accuracy and narrowed the allowable tolerances, e.g., on optical surfaces, to nanometric level. Recent success in this technology made it possible to produce microoptical lenses with very accurate aspherical surfaces.
One of the fields in which microoptics may find application is photolithography. For example, U.S. Pat. No. 6,016,185 issued to Elmar Cullman, et al. discloses an apparatus and method for photolithographic exposure of a substrate including an illumination source for providing light for producing an image on the substrate, a mask including a pattern for projection onto the substrate, a microlens assembly for projecting the light through a plurality of microlens channels onto the substrate and an actuator for moving the microlens assembly in a plane parallel to the mask and the substrate for suppressing interference effects. The above system is intended for fixed-scale (1:1) projection of an object onto an image plane. In other words, the microlenses of this system are assembled into an array that forms an objective for parallel transfer of an image without any reduction or magnification of the image.
A series of inventions made by Stephen Daniell (see, e.g., U.S. Pat. No. 6,721,101 issued in 2004) relates to the use of a microlens optical system for obtaining a 3—D image in the observer's sight. This technique is based on the principle of creation of parallax between the "left" and "right" images, which is perceived by the observer as a stereo effect.
The arrays used in the above inventions can be divided into two categories. The arrays of the first type uses air as a low-index material. Such arrays may be used, for example, in illuminated displays of electronic image detection, machine vision, and real-time 3D video capture. Arrays of the second use a fluoropolymer as a low-index material, and convey a great preponderance all incident light to the image plane.
More specifically, the system of U.S. Pat. No. 6,721,101 (as well as the systems of all other inventions of Stephen Daniell) is an assembly of two array substrates, which in an overlapped state possess better optical characteristics than a single array substrate. From the optical point of view, this system functions as follows: an object located at a finite distance from the observer is converted by the overlapped arrays into an infinitely located image which is observed with the maximum possible angle of observation. This allows the observer, who is located on the symmetry axis of a display, to clearly see on this display two independent images of one object with the left and the right eyes.
In reality, the Daniell's system does not widen the angle of observation for the observer but rather creates a virtual effect of stereo vision. In this system, the second and third surfaces of the array work as a separator of angles of incidence of light, i.e., starting from angle that exceeds a predetermined value, the light does not pass through the system but is reflected on the principle of total inner reflection, e.g., to the right eye, while the light incident at smaller angles passes through the system, is focused on the last flat plane of the lens system, and returns to the left eye.
Although the Daniell's system cannot be used for widening a real angle of observation and merely redistributes and divides the optical path of light that passes through the system for stereo effect, this system is a good example of a two-array assembly for optical purposes. The use of a sandwich composed of two overlapped film-like or plate-like arrays makes it possible to significantly reduce the geometrical dimensions of the lens system.