In an image calibration device 10, a calibration pattern is projected onto a screen 4 from each projector 3 under control of a personal computer or other calibration device 10a, pictures are taken by a digital camera or other image pick-up device 11, and the results are supplied to the calibration device 10a. The calibration device 10a uses the supplied picture data to calculate parameters in order to perform picture positioning, color adjustment, brightness adjustment and other adjustments and corrections, and based on the calculation results transforms the original picture data, generates and supplies signals indicating projection conditions to each of the projectors 3, and performs image calibration control of the pictures projected by each projector 3. Here at the time of taking pictures, by installing on the image pick-up device 11 a shielding member 12 formed into a tetragonal pyramid shape, the light-receiving part of the image pick-up device 11 and the screen are completely shielded from ambient external light. By this means, the measurement precision of the image pick-up device 11 is improved, and accurate and reliable image calibration is performed.

This application claims the benefit of Japanese Application No. 2000-60868 filed in Japan on Mar. 6, 2000, the entire disclosure of which is incorporated by reference.
1. Field of the Invention
This invention concerns an image calibration device and image calibration method for a multi-display device which combines and displays on a screen the projected pictures of a plurality of projectors, and in particular concerns an image calibration device and image calibration method capable of accurate image calibration of the projected picture of a multi-display device.
2. Description of the Related Art
In recent years, with the growing screen sizes of display devices, there has been interest in projectors which display pictures on screens by enlargement and projection.
Such projectors include, for example, liquid crystal projectors in which a picture is displayed on a liquid crystal panel based on input image signals, and by enlargement and projection, this picture is displayed on a screen. Due to the thin shape, light weight, low driving voltage, and low power consumption of the display device, liquid crystal projectors are currently the mainstream of such display devices.
Due to recent demands for increased screen sizes, so-called multi-display devices, which enable the display of large-screen pictures by combining a plurality of the above projectors, have come into use as, for example, displays for corporate advertising and various events.
In general, multi-display devices are either devices comprising a plurality of projectors accommodated by a housing and a single screen, or so-called cube-type devices in which a projector and screen set make up a single device, a plurality of which are combined in, for example, a 2xc3x972 configuration, positioning four such sets as a single display device. Other devices are front-projection-type devices in which a plurality of projectors are provided in a row, for enlargement and projection onto a single screen.
However, in the above-described multi-display device, because a picture is displayed on a large screen, measures to increase the definition of the projected image are essential, and in the past a variety of proposals have been made. For example, in a proposal described in Japanese Patent Laid-open No. 9-326981, a method to obtain high-definition projected pictures is proposed as a picture projection system.
Specifically, the picture projection system comprises means to generate high-definition picture data, picture projection means having a plurality of projectors to project at least part of the above high-definition picture data, and picture processing means to select and process at least part of the above high-definition picture data for output to the above plurality of projectors.
In such a picture projection system, a projection method is executed in which the above picture projection means is used to partially overlap the pictures of each projector to form a single large picture, and moreover picture processing is performed by the above picture processing means such that the overlapping parts of the picture are smoothly connected. To this end, first a digital camera or other picture-taking means takes a picture of reference pictures projected onto the screen by each projector, to capture the positions, colors, brightnesses, and other parameters of each picture. Thereafter, these parameters are referenced to perform calibration processing of the original picture by picture processing means within a personal computer, and smooth connection of projected pictures is achieved by output to each projector. By this means, projected pictures with higher definition are possible.
In the case of the above-described cube-type device, at the time of installation, for example, differences in brightness and color between four devices are calibrated to bring them into coincidence, to raise the definition of the projected picture. In front-projection type devices also, similar to cube-type devices, by executing a calibration method, smooth connections between projected pictures are achieved.
However, in the processing method of the above-described conventional picture projection system and calibration method of cube-type and similar devices, when such processing is executed for a multi-display device installed indoors, for example, in order to project or calibrate colors and brightness more accurately, it has become necessary to darken the room and shut out external light, in order that, there by no adverse effects of ambient external light on image calibration.
However, there are cases in which sunlight cannot be blocked, or in which other persons in the same room are performing some task and cannot extinguish lights within the room. In such cases, the ambient external light adversely affects image calibration, resulting in the problem that a satisfactory high-definition projected image cannot be obtained. This problem is particularly marked when a multi-display device is installed outdoors, and cannot easily be solved.
Further, in conventional multi-display devices it is desirable that, at the least, a clean screen be used for accurate execution of the above-described image calibration processing. Consequently the screen surface must be cleaned. However, there is the added problem that such cleaning has conventionally entailed complex tasks, and has been troublesome.
As explained above, in conventional picture projection systems and multi-display devices, when it is not possible to shut out external light adversely affecting image calibration, for example, if, when installing a multi-display device indoors, it is not possible to block out sunlight, or if other persons are performing tasks in the same room and lights in the room cannot be extinguished, the ambient external light adversely affects image calibration, and as a result satisfactory high-definition projected images cannot be obtained. Such problems are especially prominent when a multi-display device is installed outdoors, and resolution of such problems is extremely difficult.
This invention was devised in light of the above problems, and has as an object the provision of an image calibration device and image calibration method which is capable of blocking out external light in the vicinity of the device, which is of simple construction, and which is capable of accurately performing image calibration processing.
The image calibration device of this invention is an image projection device which projects a plurality of images onto different positions on a screen by means of a plurality of image projection devices (projectors), and which calibrates the image by using an image pick-up device to take a picture of the image on the screen formed in this way, and which is characterized in comprising a shielding member, provided so as to extend from the screen toward the image pick-up device and to be located outside the area surrounded by lines connecting all or part of the screen and the image pick-up device, to block outside light, the image pick-up device, to take pictures of images on the screen projected by at least one of the plurality of projectors and, a calibration device which calibrates the conditions for projection of the projectors, based on image data obtained from the picture-taking results.
The image calibration method of this invention is a method for calibrating images by using a plurality of image projection devices (projectors) to project a plurality of images onto different positions of a screen by, and using an image pick-up device to take pictures of the images thereby formed on the screen, comprising the steps of providing a shielding member which shields external light, so as to extend from the screen toward the image pick-up device and to be located outside the area surrounded by lines connecting all or part of the screen and the image pick-up device, projecting a plurality of images at different positions on the screen by the plurality of projectors, taking pictures of images on the screen projected by at least one of the plurality of projectors, by using the image pick-up device, calibrating the projection conditions of the image projection devices based on the image data obtained from these results, and, after taking pictures using the image pick-up device, removing the shielding member from the image area on the screen on which images are displayed and from the space located in the normal direction of this image area.

Image calibration device and image calibration method


An object of the present invention is to provide a sensor unit that can detect a wide range of physical quantity changes with a higher degree of freedom than in the conventional art and is capable of reporting detection information, and a multiple-type sensor using the sensor unit. A flow sensor in the present invention includes a board, a sensor that is arranged on the board and detects a physical quantity change, a plurality of external connection terminals that are electrically connected to the sensor, and a reporting part that reports detection information of the sensor to the outside. In the present invention, a wide range of physical quantity changes can be detected with a higher degree of freedom. Connecting a plurality of sensor units enables use for various applications.

Patent Literature 1 discloses an invention relating to a wind speed sensor that can measure a wind speed. For example, the wind speed sensor disclosed in Patent Literature 1 includes a board, a heater resistor mounted on the board, a signal leading pin, and the like. The wind speed is detected based on the magnitude of the heat radiation effect.

Sensor unit, and multiple-type sensor using the same


To improve a communication system including two communication apparatuses so as to reduce a possibility of having communication decrypted by a third party. The communication system includes a first communication apparatus and a second communication apparatus, where one of the communication apparatuses encrypts transmission subject data and transmits generated encrypted data to the other communication apparatus which decrypts received encrypted data. Each of the communication apparatuses generates an algorithm used for encryption each time it performs the encryption or decryption. In this case, each of the communication apparatuses generates the algorithm by assigning past solutions to a solution generating algorithm capable of having the past solutions assigned thereto and thereby generating a new algorithm. The past solutions are erased when they are no longer used.

The above-mentioned communication system is used in a situation where it is necessary to keep transmission subject data transmitted between two communication apparatuses confidential to a third party. Although various encryption techniques are proposed and used in order to keep the transmission subject data confidential, it is difficult to completely prevent decryption of a code.
In general, communication performed by encrypting the transmission subject data is performed by using a procedure of cutting the transmission subject data by a predetermined number of bits on a transmitting and receiving apparatus on a transmitter side, encrypting each piece of the cut data and transmitting it to the communication apparatus at the other end and decrypting received data on the transmitting and receiving apparatus on a receiver side.
In the case of performing such encryption, an algorithm and a key which are predetermined are generally used. This algorithm is rendered very complicated to prevent the decryption of the code, and the key is also changed in predetermined timing in many cases. Once the algorithm and key are known, however, it is relatively easy to break the encrypted data by using the algorithm and key even if the algorithm is rendered complicated or the key is changed.
The inventors hereof studied encryption technology for many years and previously invented a technique for performing encrypted communication wherein each of the communication apparatuses on the transmitting side and the receiving side is provided with common means for successively generating at least one of the algorithm and key for performing the encryption and decryption so as to perform the encrypted communication while successively changing at least one of the algorithm and key used for the encryption and decryption.
This technique successively generates at least one of the algorithm and key for performing the encryption and decryption. Even in the case where the algorithm or the key is known once, the algorithm or the key or both of them change thereafter. Therefore, strength thereof is much higher than conventional encryption technology.
As for this technique, however, there are the cases where, if some of the past algorithms or keys are known, it is predictable as to how the algorithm or the key or both of them change from now on. Thus, a possibility of being broken by a third party is not absolutely zero.
An object of the present invention is to improve the communication system including two communication apparatuses capable of encrypting transmission subject data in plain text to render it as encrypted data and then transmitting it to the communication apparatus at the other end and also decrypting received encrypted data and rendering it as the transmission subject data so as to reduce the possibility of being broken by a third party.

Communication system and communication method


A system is configured to receive a geographical indicator, to determine at least one light beacon (61-69) based on the geographical indicator, to output information (82) identifying the at least one light beacon, to receive a selection of one or more (61-68) of the at least one light beacon, to receive a content item or a reference to a content item in relation to the one or more light beacons, and to associate the content item with the one or more light beacons. The association causes the one or more light beacons to transmit data via visible light which enables reproduction of the content item.

The provision of location-dependent content inside buildings is becoming increasingly popular and is used in museums and shops, for example. As GPS location determination does not work properly inside buildings, beacons are often used inside buildings instead of GPS to provide location-dependent content. Beacons can also be used outdoors.
US 2016/0277999 A1 discloses a mobile content management system which includes a plurality of distributed beacon transmitters, each configured to continuously broadcast messages including a host URL. Client devices proximate to one or more of the beacons are able to receive the broadcast message and subsequently transmit content requests to the host server located at the host URL. The host server returns an appropriate destination URL whose content may be obtained by the client device and reproduced on the client device. Administrators can use a web portal to associate beacon IDs with destination URLs. This may be done for multiple beacons in one action using a bulk edit feature.
A drawback of the web portal disclosed in US2016/0277999 A1 is that it has not been designed for users who are not administrators, e.g. social media users who want to share content with people who are present at the same event. The web portal requires the administrator to know and enter beacon IDs and is therefore not suitable for users who are not administrators, i.e. users that do not know the relevant beacon IDs and/or do not only want to associate content with the same set of beacons again and again.

Associating content with one or more light beacons based on geographical indicator


An apparatus for determining friction between a support roller and a rubber roller comprising an adjustable horizontal seat board, a pivoted stand supporting a pivot spindle in parallel to the seat board, an adjustable horizontal pressure pad for applying even downward pressure, a clamping and driving assembly for clamping two ends of the rubber roller, a support roller for supporting one end of the paper, a paper holding device with rollers below for holding the other end of the paper, a load cell in connection with the paper holding device for conveying a pull from generated friction, and a set of weights for selecting to be placed on the horizontal pressure pad. In use, the rubber roller, evenly pressing on one end of the paper, may be driven into turning at a fixed speed to allow a relatively accurate frictional factor to be detected.

In today's photocopier, fax machine, printer, money machine and automatic selling machine, transmission of paper or bank notes merely takes advantage of the friction generated between the rubber roller and the paper to be fed. However, the machine's reliability is questioned. Up until the present invention, the standardization of the frictional factor was still found to be difficult, and consequently the production of a properly fitting rubber roller was difficult to achieve. Reliability seems to be obtainable only with numerous tests. As for determining the frictional factor, a spring scale capable of measuring how much force is used to pull out a paper sheet held between rubber rollers is conventionally used. The frictional factor (u) could then be calculated by dividing the measured force by the pressure exerted between rubber rollers. Although simple, the test result will be in a wide error range due to difficulty in maintaining a fixed pulling seed.

Apparatus for determining friction between a support roller and a rubber roller

No. 35-19, Hsia-Kuo Ln., Tai-Ping Rd., Ta-Li Hsiang


A method for dynamically controlling regenerating energy flow and direct current bus voltage for an adjustable frequency drive system includes sensing a direct current voltage of a direct current bus; and sensing a plurality of alternating currents at outputs of an inverter. The sensed alternating currents are transformed to a stationary current vector. Voltage and frequency values are converted to a stationary voltage vector and an angle. The angle and the stationary current vector are transformed to a rotating current vector including torque and flux producing current components. An induction machine generating mode is determined when the torque producing current component reverses polarity. The voltage and frequency values limit the direct current voltage of the direct current bus at a predetermined threshold responsive to the generating mode. The stationary voltage vector and the angle are converted to pulse width modulated control inputs of the inverter.

1. Field of the Invention
The invention relates to adjustable frequency drive (AFD) systems and, in particular, to such AFD systems, which control the speed, torque, horsepower and/or direction of an induction machine, such as an AC motor.
2. Background Information
An Adjustable Frequency Drive (AFD) system may be employed in a wide range of commercial applications, such as, for example, HVAC, fans, pumps, conveyors, material handling and processing equipment, and other general industries, such as, for example, forest products, mining, metals and printing.
If the stator terminals of an induction machine are connected to a three-phase AFD system, then the rotor will rotate in the direction of the stator rotating magnetic field. This is the induction machine motoring mode of operation. When load torque is applied to the motor shaft, the steady state speed is less than the synchronous speed.
When the induction machine speed is higher than the synchronous speed, and the induction machine rotates in the same direction as the stator rotating field, then the induction machine is in the generating mode of operation. A generating torque acting opposite to the stator rotating magnetic field is produced. For example, to stop an AFD system, the power supply frequency is gradually reduced. In the deceleration process, the instantaneous speed of the AFD system is higher than the instantaneous synchronous speed because of the system inertia. As a result, the generating action of the induction machine will cause the power flow to reverse and the kinetic energy of the AFD system is fed back to the power supply source.
For AFD systems, the braking or regenerative energy of the system flows, for example, from the motor, through diodes in the inverter section of the drive, and into DC bus capacitors. Typically, the input diodes of the upstream converter do not provide a path for this energy to be returned to the AC power line. Hence, the regenerative current flows into the DC bus capacitance and, thus, the DC bus voltage increases.
There are four common methods to deal with the high DC bus voltage due to the regenerating condition. The first method employs silicon controlled rectifiers (SCRs), insulated gate bipolar transistors (IGBTs) or gate controlled thyristors (GCTs or GTOs), as converters in order to both provide power to the DC bus when motoring and to regenerate from the DC bus back to the AC line when braking. This method has the disadvantage of relatively higher cost since the converter section is similar to or the same as the inverter section.
The second method simply initiates a drive fault and trip when the DC bus voltage becomes too high. The disadvantage of this solution is the disruption of the process because of a resulting shut down or nuisance trip.
The third method handles the regenerating energy without tripping by employing a braking resistor, which provides a path to dissipate the regenerative energy. A braking resistor control circuit senses the high voltage condition and, then, electrically connects the braking resistors across the DC bus. The braking resistors (e.g., bus clamps; snubbers; voltage limiters) dissipate the excess energy. For example, for 230 VAC drives, the DC bus is approximately 310 VDC, and for 460 VAC drives, the DC bus is approximately 620 VDC. The actual DC bus voltage is about 1.35 times the RMS AC line voltage. The current through the braking resistor is proportional to the DC bus voltage divided by its resistance. For example, a 20 xcexa9 resistor module connected across a 460 VAC line dissipates about 10 kW, while the same resistor dissipates about 20 kW when electrically connected to a DC bus, which is produced by rectifying a 3-phase AC line for a 460 VAC drive. The costs of the braking resistor can be significant, while the physical size of the resulting drive assembly increases. Both of these are normally undesirable results.
The fourth method actively limits the DC bus voltage at a safe threshold by applying proper control algorithms in response to regenerating conditions. However, when the induction machine operates in its normal motoring mode, the high input (utility) AC line voltages can push the DC bus voltage to reach the regenerating voltage threshold. In order to prevent the control algorithms from limiting the DC bus voltage in this scenario, it is known to employ input AC potential transformers or other voltage amplifier apparatus to measure the AC line input voltages. This approach similarly has the disadvantages of relatively higher cost and relatively larger physical dimensions.
The known solutions to handle AFD regenerating conditions have the disadvantages of shutting down industrial processes, relatively higher equipment costs and/or relatively larger physical sizes.
The generating mode of an AFD system causes the DC bus voltage to rise. The AC line input voltages to the system can be higher than the rated value in steady state. Also, momentary surges can occur in such voltages of any electrical distribution system, thereby causing a relatively higher DC bus voltage to be present in these cases. Therefore, it is difficult to determine which source is creating the energy that results in an over-voltage condition on the DC bus.
There is room for improvement in AFD systems and methods and apparatus for controlling the same.
These needs and others are met by the present invention, which identifies and controls regenerating energy flow for Adjustable Frequency Drives (AFDs). This regenerating energy flow is developed in both steady state and dynamic operating conditions of a three-phase induction machine, which is controlled by the AFD. The method and apparatus distinguish the energy source both in steady state and in dynamic transient conditions.
The three-phase currents of the AFD are converted into a stationary vector of current. The three-phase AC currents are measured by employing suitable current sensors (e.g., Hall effect) and are transformed into two-phase AC currents through the Clarke Transformation in the stationary reference frame. A space vector technique is employed to develop an angle. The Park Transformation employs the two-phase AC currents and the angle to produce two-phase DC current vectors in the rotating reference frame. These DC current vectors include the induction machine torque and flux producing components.
If the torque producing current vector reverses its polarity (e.g., direction; sign) when the commanded speed is less than the actual rotor speed, then the regenerating condition is confirmed.
If the regenerating condition is true, then a control algorithm turns on to limit the rising DC bus voltage at its predetermined threshold. When the induction machine is in the regenerating mode, the DC bus voltage is clamped at the predetermined threshold without tripping. The DC bus voltage is regulated dynamically by a compensation module, in order to stay at the predetermined threshold, thereby controlling the regenerating energy flow without necessarily tripping the AFD or adding costs and sizes to the overall electrical system. After the regenerating energy is dissipated and the induction machine is no longer in the generating mode, the DC bus voltage is automatically reset to the normal level in the motoring mode.
If the regenerating condition is not true, then the predetermined threshold adjusts itself based on the DC bus voltage level as determined by the AC line inputs.
The present invention provides a stable operating system and eliminates the disadvantages of the known prior art. In addition, the torque and flux producing current vectors in the rotating reference frame may be employed to conveniently calculate the induction machine power factor.
As one aspect of the invention, a method for dynamically controlling induction machine regenerating energy flow and direct current bus voltage for an adjustable frequency drive system comprises: sensing a direct current voltage of a direct current bus; sensing a plurality of alternating currents at alternating current outputs of an inverter; transforming the sensed alternating currents to a stationary current vector; converting a voltage value and a frequency value to a stationary voltage vector and an angle; transforming the angle and the stationary current vector to a rotating current vector including a torque producing current component and a flux producing current component; determining a generating mode of the induction machine when the torque producing current component reverses polarity; employing the voltage value and the frequency value to limit the direct current voltage of the direct current bus at a predetermined threshold responsive to the generating mode of the induction machine; and converting the stationary voltage vector and the angle to pulse width modulated control signals for the control inputs of the inverter.
As another aspect of the invention, an adjustable frequency drive for an induction machine comprises: a converter including a plurality of alternating current inputs and a direct current output having a first node and a second node; a capacitor electrically connected between the first and second nodes of the direct current output; an inverter including a direct current input, a plurality of switches, a plurality of control inputs, and a plurality of alternating current outputs, the direct current input electrically connected to the direct current output, the alternating current outputs adapted to electrically connect to alternating current inputs of the induction machine; each of the switches electrically connected between one of the first and second nodes and one of the alternating current outputs of the inverter, each of the control inputs controlling one of the switches; a voltage sensor sensing a direct current voltage at the direct current output of the converter and outputting a sensed voltage value; a plurality of current sensors sensing a plurality of alternating currents at the alternating current outputs of the inverter and outputting a plurality of sensed current values; and a processor comprising: a plurality of inputs for the sensed current values and the sensed voltage value, a plurality of outputs for the control inputs of the inverter, a Clarke Transform module transforming the sensed current values to a stationary current vector, a space vector module including a plurality of inputs and a plurality of outputs, the inputs of the space vector module comprising a set voltage value, a set frequency value, a change voltage value, and a change frequency value, the outputs of the space vector module comprising a stationary voltage vector and an angle, a pulse width modulation module including a plurality of inputs and a plurality of outputs, the inputs of the pulse width modulation module comprising the stationary voltage vector and the angle, the outputs of the pulse width modulation module providing the control inputs of the inverter, a Park Transform module transforming the angle and the stationary current vector to a rotating current vector, and a regeneration override module comprising a plurality of inputs and a plurality of outputs, the inputs of the regeneration override module comprising the sensed voltage value and the rotating current vector, the outputs of the regeneration override module comprising the change voltage value and the change frequency value, the regeneration override module dynamically controlling regenerating energy flow from the induction machine to the direct current output of the converter.
As another aspect of the invention, an adjustable frequency drive system comprises: a three-phase induction machine; and the adjustable frequency drive.

Method and compensation modulator for dynamically controlling induction machine regenerating energy flow and direct current bus voltage for an adjustable frequency drive system


A resonant inverter has transistor switches (20, 30) arranged to conduct current from a d.c. source (10) alternately in one direction and the other through an inductor (40) and capacitor (42). The transistor switches (20, 30) are turned on alternately by signals from secondary windings (24, 34) of a drive transformer (44) having a primary winding (45) in series with the inductor (40) and capacitor (42). To control the output power of the inverter, a control circuit (50) senses reversal of current in through the inductor (40) and capacitor (42) and turns off one of the transistor switches (30 ) a predetermined time after current reversal. Current reversal is sensed by an additional transformer (60) having a primary winding (61) in series with the inductor (40) and capacitor (42). The control circuit (50) includes a timer (52) controlling the predetermined time, which may be varied to vary the power output of the inverter. A load (80) is connected across the inductor (40 ) or capacitor (42 ) .

1. Field of the Invention
This invention relates to inverters.
More particularly, the invention relates to inverters of the kind comprising a resonant circuit including a capacitor and an inductor, a first main switching device arranged to conduct current from a d.c. source in one direction through the capacitor and inductor, a second main switching device arranged to conduct current from the d.c. source through the capacitor and inductor in the opposite direction, and drive means for causing the switching devices to conduct alternately, the drive means comprising a transformer having a primary winding in series with the capacitor and inductor and two secondary windings arranged to provide drive signals to the respective main switching devices.
2. Description of Related Art
An inverter of this kind is described in published European patent application EP-A-0 121 917. The described inverter operates at the resonant frequency of the resonant circuit, the main switching devices being switched at the zero crossing points of the oscillatory current in the resonant circuit, and there is no means of controlling the power output of the inverter.
A paper by Sebastian et al, entitled "Regulating Self-Oscillating Resonant Converters", 2nd European Conference on Power Electronics and Applications held at Grenoble, France, on 22-24 Sep., 1987 describes an inverter in which switching of the field-effect transistors forming the main switching devices is effected by two saturable transformers with primaries connected in the resonant circuit and secondaries connected to the gates of the field-effect transistors, so that the drive to each transistor is removed when the associated transformer saturates. Each transformer has an additional winding through which a variable controlled d.c. current is fed, to control the point at which the transformer saturates. The switching of the transistors can thereby be controlled to control the phase difference between the voltage and current in the resonant circuit so as to control the power output of the inverter. However, the described inverter is relatively complex.


A laser apparatus that allows selection of a wavelength of output light from a plurality of options. The laser apparatus includes: a resonator made up from an output mirror and reflection means having a plurality of reflective surfaces fixed in position; a laser medium disposed on an optical axis inside the resonator; branch means branching an optical path of a light beam formed on the optical axis when light oscillates in the laser medium into a plurality of optical paths having an end at one reflective surface of the reflection means, the branch means forming a first optical path coinciding with the optical axis when located out of the optical axis, and forming a branch path by moving the light of the optical axis parallel when located on the optical axis.

1. Field of the Invention
The present invention relates to a tunable laser apparatus and a photoacoustic apparatus that uses this laser apparatus.
2. Description of the Related Art
Photoacoustic tomography (PAT) apparatuses that use lasers for medical applications have been developed (see Non-Patent Literature 1). PAT apparatuses are expected to be used for determination of presence or absence of a tumor through observation of blood vessels congregating around a tumor in a living body, or for functional analysis of tissues based on the differences between oxyhemoglobin and deoxyhemoglobin spectra.
A PAT apparatus emits nanosecond laser pulses to a segment being measured and analyses received signals converted from ultrasound waves (photoacoustic waves) generated by the photoacoustic effect to obtain an image. As the light intensity decays by diffusion in the living body, it is necessary to emit laser beams with high energy per pulse to obtain a photoacoustic wave from a segment relatively deep in a living body such as a breast, in particular.
Some lasers called tunable lasers that use titanium sapphire or alexandrite, which is a laser medium with a broad gain bandwidth, allow selection of a wavelength. Generally, to induce laser oscillation at a desired wavelength, tunable lasers use a wavelength selection mechanism that includes an optical element such as a prism, a diffraction grating, or a birefringent plate. The optical element is arranged on an optical axis inside a resonator and mechanically moved to allow selection of a wavelength at which oscillation should take place.
If a prism is used as an element of the wavelength selection mechanism, generated beams of respective wavelengths are resonated in the resonator correspondingly to the angular deviation of the optical paths that is determined by the refractive index of the prism. If the prism itself is used as a reflective mirror of the resonator, the prism is mechanically rotated in the plane of the substrate forming the resonator. If a separate reflective mirror is used with the prism, the prism is fixed in position, while the reflective mirror located correspondingly to the angular deviation of the optical path of respective wavelengths is mechanically rotated.
If a diffraction grating is used as an element of the wavelength selection mechanism, a reflective mirror is mechanically rotated in accordance with an oscillating wavelength for selection of the target wavelength, as with the prism.
If a birefringent plate is used as an element of the wavelength selection mechanism, the birefringent plate is mechanically rotated such as to maintain the angle of the optical axis of the beam being resonated relative to the incident and exit surfaces of the birefringent plate at a constant angle.
In another known method (Patent Literature 1), light of two different wavelengths is produced at the same time in the resonator, and with a wavelength selective filter disposed outside the resonator inserted onto the optical axis or retracted from the optical axis, a target wavelength is selected.    Patent Literature 1: Japanese Patent Application Laid-open No. 2007-248304    Non-Patent Literature 1: S. Manohar et al, Proc. of SPIE vol. 6437 643702-1

Laser apparatus and photoacoustic apparatus


Responsive to a hydraulic piston advancing out of a piston housing in a second brake arm and contacting a piston cam surface of a first brake arm, the second brake arm pivots around a second pivot. As this is happening, a cam surface in the second brake arm lifts a contact surface of a first force transfer member of the first brake arm, imparting torque to the first brake arm which then pivots around a first pivot. The cam surface is shaped to impart synchronous motion to the first and second pad holders. Splitting one of the brake arms with a centering member permits a centering adjust feature.

The present disclosure is directed to bicycle brakes and, more particularly, to bicycle rim brakes.
In general, there are two types of rim brakes. One is referred to as a single pivot rim brake and the other is referred to as a two-post rim brake. The two-post rim brake usually includes a first brake arm pivotable about a first axis and a second brake arm pivotable about a second axis. The first and second brake arms include a link or connection therebetween for moving the brake pads at the same rate. A disadvantage of a two-post brake is the braked induced frame/fork post loads. There is a need to provide a two-post rim brake with reduced frame/fork post loads.


A method of manufacturing a semiconductor device characterized by its high-speed operation and high reliability is provided in which a semiconductor layer crystallized by a CW laser is used for an active layer of a TFT. When a semiconductor layer is crystallized by a CW laser, one part is formed of large crystal grains whereas another part is formed of microcrystals due to the width-wise energy density distribution. The former exhibits excellent electric characteristics. The latter has poor electric characteristics because grain boundaries hinder movement of electric charges, and therefore causes inconveniences when used as an active layer of a transistor. Accordingly, circuits are arranged such that a semiconductor layer formed of large crystal grains is used for the active layer of every TFT.

1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device that includes a laser beam irradiation step, and the present invention also relates to a semiconductor device manufactured thereby. Note that a semiconductor device described here includes an electro-optical device such as a liquid crystal display device or a light-emitting device, and an electronic device that includes the electro-optical device as a display portion.
2. Description of the Related Art
In recent years, an extensive study has been made on a technique in which an amorphous semiconductor film formed on an insulator, especially a glass substrate, is crystallized so that a crystalline semiconductor film is obtained. As the methods of crystallization such as a thermal annealing method using furnace annealing, a rapid thermal annealing method (RTA method), a laser annealing method and the like were examined. Anyone thereof or combining two or more methods thereof can be carried out for crystallization.
On the other hand, an active matrix display device using a thin film transistor (hereafter referred to as TFT) manufactured by forming a semiconductor thin film is widely adopted. Active matrix display devices using TFTs have several hundred thousand to several million pixels arranged in a matrix shape, and an image display is performed by controlling the electric charge of each pixel by using TFTs disposed in each pixel.
Recently, techniques that are used for simultaneously forming driver circuits by using TFTs in the periphery of a pixel portion in addition to pixel TFTs that comprise pixels have progressed. A crystalline semiconductor layer has extreme higher electric field effect mobility in comparison with an amorphous semiconductor layer, therefor, it is practicable for forming an active layer of TFT (hereafter simply referred to as active layer, the active layer includes a source region, a drain region, and a channel formation region) used for such circuits.
Generally, in order to crystallize an amorphous semiconductor in annealing furnace, a thermal treatment at 600° C. or more for 10 hours or more is required. Therefor, applicable material of substrates is limited to quartz that is capable of withstanding the heat treatment. However, the quartz substrate is expensive in price, and is difficult to be manufactured in a large area.
In order to improve the manufacturing efficiency, manufacturing the substrate in a large area, and mass production are unavoidable, it is expected that a substrate in which a length of one side exceeds 1 m will be also used in recent years.
On the other hand, a method of thermal crystallization by using metal elements disclosed in Japanese Patent Application Laid Open No. 7-183540 enable the crystallization temperature which was a conventional problem to be realized at a low temperature. The crystalline semiconductor film can be formed by this method in which a small amount of an element such as nickel, palladium and lead is added to an amorphous semiconductor film, then the amorphous semiconductor film is heated for four hours at 550° C.
Since the laser annealing method can deliver high energy only to the semiconductor film without substantially increasing the temperature in substrate by focusing the semiconductor layer, the laser annealing technology comes under spotlight by its appliance in a glass substrate with a low strain point as a matter of course, and a plastic substrate, etc.
An example of the laser annealing method is a method of forming pulse laser beam from an excimer laser or the like by an optical system such that it becomes a square spot of several cm or a linear shape of 100 mm or more in length on an irradiation surface, and relatively shifting an irradiation position of the laser beam with respect to the irradiation surface to conduct annealing. The "linear shape" described here means not a "line" in the strict sense but a rectangle or a prolate ellipsoid shape having a high aspect ratio. For example, the linear shape indicates a shape having an aspect ratio of 2 or more (preferably 10 to 100). Note that the linear shape is used to obtain an energy density required for annealing an object sufficiently to be irradiated. Thus, if sufficient annealing is conducted for the object to be irradiated, it may be a rectangular shape, a tabletop shape or any other shapes.
The state is shown in FIG. 8. After an amorphous semiconductor layer is formed on a substrate 801, a linear laser 803 is scanned and crystallized in a direction of an arrow. At this time, a cross-sectional view in which a dotted line is shown by A-A′ is shown in FIG. 8B. An insulation layer 811 is formed on the substrate 801 as a base layer, an amorphous semiconductor layer 813 is formed thereon. In addition, for the insulation layer 811, a single layer is illustrated in FIG. 8, but a structure without an insulation layer, or a structure of a laminate film having two or more layers also may be used.
Then, the linear laser 803 is scanned and irradiated on the substrate. At this time, in a region 812 irradiated by the linear laser, the amorphous semiconductor layer is in a state of molten, and after the passage of the irradiation region, the amorphous semiconductor layer is recrystallized. As described above, a crystalline semiconductor layer 815 is formed. However, a crystalline semiconductor film formed by subjecting an amorphous semiconductor film to laser annealing includes a collection of a plurality of crystal grains, and the position and size of the crystal grains are random. TFTs are formed on a glass substrate by patterning the crystalline semiconductor layer in an island shape for device separation. In this case, the position and size of crystal grains cannot be specified. In comparison with the inner of crystal grains, the interface of crystal grains has an infinite number of a recombination centers or a trapping centers caused by an amorphous structure, a crystal defect, and the like. If the carriers are trapped in trapping centers, potential at a grain boundary will be increased and become barriers to carriers, it is known that current transporting characteristics of carriers will be degraded caused by this. However, it is almost impossible to form a channel formation region by using a single crystal semiconductor film while avoiding the influence of a crystal boundary, although crystal properties of semiconductor film of channel formation region have a serious effect on the TFT characteristics.
There is a technique of irradiating a semiconductor layer with a CW (continuous wave) laser beam by running the beam in one direction to make a crystal grow continuously in the scanning direction and obtain a single crystal stretching long in the scanning direction. It is considered that this method can provide a TFT having almost no grain boundaries at least in its channel direction. However, in order to obtain excellent crystallinity, a region of an amorphous semiconductor layer that is irradiated with a laser has to be melted completely. For that reason, the laser irradiation region is converged into a rectangle or ellipse having a width of several hundreds μm to secure enough energy density and the surface of the irradiation object is scanned with laser light as shown in FIG. 1A to crystallize the entire surface thereof. As a result, crystal grains that are long in the scanning direction are formed to grow into a crystalline semiconductor layer as shown in FIG. 1B.
Here, attention is paid to the energy density in the laser irradiation width direction. When laser light is collected spot-like in a region, there is an energy density distribution starting from the center of the irradiation region toward the edges as in an example shown in FIG. 1C. Although the energy density distribution varies depending on the laser oscillation mode, a region low in energy density is generally incapable of providing an energy for melting a semiconductor layer sufficiently. This region of the semiconductor layer cannot grow large crystal grains and can only have microcrystals. Accordingly, in a semiconductor layer treated with a CW laser, a crystalline semiconductor layer A 112 where crystal grains grow into satisfactory large sizes and a crystalline semiconductor layer B 113 having microcrystals are formed for each scanned region (an irradiation region of when the CW laser scans one line) as shown in FIG. 1B.
In the semiconductor layer A, excellent electric characteristics are obtained as mentioned above. On the other hand, the semiconductor layer B has countless numbers of grain boundaries and therefore cannot provide satisfactory electric characteristics.
If the semiconductor layer as such is patterned and used to form TFTs, there is a large difference in electric characteristic between a TFT which includes the semiconductor layer B in its channel formation region and a TFT which doesn't. Therefore, it is difficult to manufacture a semiconductor device that operates satisfactorily from these TFTs despite many elements included in them which have excellent electric characteristics.

Method of manufacturing a thin film transistor

Semiconductor Energy Laboratory Co., Ltd.


A method and apparatus for solar heating a leach solution prior to its distribution over an ore heap. The apparatus includes a heat absorbing mat having a series of individual heat absorbing tubes joined to each other by heat reflecting panels. The heat reflecting panels and heat absorbing tubes collect and transfer solar energy to the leach solution passing through the heat absorbing tubes. The temperature of the leach solution passing through the heat absorbing tubes is elevated above ambient prior to the leach solution being distributed to a series of emitter tubes positioned on top of the ore heap. The array of emitter tubes are connected to the heat absorbing mats such that the leach solution is heated within the mat and immediately distributed to the emitter tubes for distribution onto the ore heap.

The present invention relates to heap leach mining. More specifically, the present invention relates to a method and apparatus used in heap leach mining that involves solar heating and distribution of a leach solution prior to its percolation through an ore heap.
Copper is frequently recovered from extremely low grade ores and from mine wastes by a process known as heap leaching. The term xe2x80x9cheapxe2x80x9d as used in the art means a bed of low grade ore that has been suitably spread over a prepared surface or xe2x80x9cpadxe2x80x9d. A dilute sulfuric acid solution is percolated through the heap and the xe2x80x9cpregnantxe2x80x9d copper-bearing acid solution is collected after it has percolated through the heap. Typically, the pad on which the heap rests is formed from an impervious material, such as sheets of plastic film (polyethylene), asphalt and/or compacted clay. The heap is often times constructed on an incline such that the copper-bearing leach solution that has percolated through the heap is collected in a reservoir.
The heap of ore is normally piled onto each impervious pad to a depth of 10 to 30 feet after the ore has been pre-crushed to a sufficiently small size to enable the leach solution to reach the metallic-mineral particles contained in the ore. It is a characteristic of heap leach mining that the maximum amount of copper can be recovered from the ore over a long period of time, typically measured in months and years. For example, a typical heap leach operation may reach a maximum copper recovery in a period of two to three years.
After the leach solution has passed through the ore heap, the copper-bearing leach solution is subjected to a solvent extraction process in which the copper is transformed from dilute leach solution into a pure and concentrated solution termed advance electrolyte. After the extraction, the advance electrolyte is subjected to an electro-winning process in which the dissolved copper plates out onto permanent stainless steel plates or pure thin copper sheets used as cathodes. The plated copper on each of the stainless steel cathodes can be removed and processed. The copper sheets, when used, grow in weight and can be processed as required.
Conventional percolation systems for heap leach mining normally includes a series of individually spaced emitter tubes extending over the heap of ore. Each of the spaced tubes receives the leach solution and includes a series of openings to permit the leach solution to be distributed for uniform percolation down through the heap. An example of such a system is shown in the Krauth U.S. Pat. No. 5,030,279. In this type of system, each of the individual tubes are laid out over the ore heap in the desired spaced relationship such that the leach solution adequately permeates through the ore heap.
In heap leach operations, it has been found that metal recoveries are considerably lower in the winter season due to lower temperatures of the ore and the leach solution. Heap leach operations, utilizing both chemical and biological leach solutions, tend to operate most efficiently at temperatures above ambient. While others have proposed heating the leach solution at a location remote from the heap, heating the leach solution at such a remote location has proven to be very inefficient due to the substantial amount of heat lost to atmosphere as the leach solution is distributed to the tubing placed on the heap.
An example of a type of heaping and distributing system proposed to solve such problems is shown in the Lane U.S. Pat. No. 6,149,711. In the Lane ""711 patent, a distribution mat having a series of individual emitter tubes connected to each other by heat absorbing panels is disclosed. The distribution mat is laid out over the heap and the temperature of the leach solution passing through the emitter tubes is elevated above ambient prior to the leach solution circulating down through the ore heap through openings formed in the emitter tubes of the mat. Although this type of system has proven to be an effective way to increase the temperature of the leach solution prior to the distribution over the ore heap, the pores formed in the emitter tubes create a problem in forming the mat and substantially increase the cost of the mat.
Therefore, it is an object of the present invention to provide a method of increasing the rate at which a semi-precious metal can be extracted from an ore heap. It is a further object of the invention to provide a method that solar heats a leach solution prior to the leach solution being distributed over the bed of ore. It is an additional object of the invention to provide a method that solar heats the leach solution immediately prior to the leach solution being percolated through the ore heap. Further, it is an object of the invention to provide an apparatus that increases the temperature of the leach solution immediately prior to the leach solution being applied to the ore heap. It is a further object of the invention to provide an apparatus that solar heats the leach solution prior to its percolation through the ore heap.
The present invention is a method and apparatus for heating a leach solution that is applied over the surface of the dump. The apparatus is a heating tube and mat assembly having a plurality of tubes joined to a underlying mat.
Each of the heat absorbing tubes is joined to the heat absorbing/heat retaining mat providing for a generally flat cover for the surface of the leach dump. The mat and tubes positioned over the surface of the dump collect solar energy. The solar energy absorbed by each of the heat absorbing tubes is transferred by conduction to the leach solutions passing through the heat absorbing tubes. The transferred heat elevates the temperature of the leach solution above ambient prior to the leach solutions being supplied to a separate array of drip lines or emitter tubes positioned on the surface of the ore heap.
In the preferred embodiment of the invention, the heat absorbing tubes are joined by a flexible material such that the heat absorbing tubes absorb solar energy that is then transferred to the leach solution. Preferably, the material used to form the heat absorbing mat is sufficiently flexible to allow the distribution mat to be rolled onto a spool when not in use. The spacing between the individual heat absorbing tubes is determined by the specific application for the distribution mats.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.

Method and apparatus for solar heating a mining leach solution


A composition for forming a dried lens-shaped pellet and processes therefore, are provided. The composition comprises 20 to 40% by weight albumin, about 2 to 5% by weight starch, about 40 to 90% by weight of sugar and/or salt, and about 102 to 1011 microorganisms per gram of the composition. The microorganisms include bacteria, viruses, yeasts, protozoa, and fungi. A process for producing the pellet includes mixing the microorganisms with the albumin and starch to form a mixture, reducing water activity of the mixture by adding the sugar and/or salt to the mixture, shaping the mixture into pellets and drying the pellets under vacuum and at a temperature lower than about xe2x88x9210xc2x0 C. Also a process for producing a suspension of microorganisms includes resuspending the pellet into a suitable medium. Further, other processes using the pellet include fermentation, reconstituting for purposes of testing, and preserving.

Not applicable.
Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to a composition for preserving determined and reproducible amounts of micro-organisms.
It relates further to lens-shaped pellets comprising such a composition.
It has also as an object a process for producing such pellets.
2. Description of Related Art
The presence of benzene in mineral water Perrier, Listeria in cheese or epizooty of bovine spongiform encephalopathy have made quite a stir. The companies in the field of water, foodstuffs or health, positioned in sensitive sectors, have customers quite attentive to the quality of the goods delivered to them. Thus, the prevention of crisis situations is vital. In fact, any incident, such as a contamination, may have serious consequences for companies (waste production, image degradation). Consequently the danger of a contamination is a major concern for the authorities who edict increasingly stronger national, European or international regulatory constraints in terms of microbiological safety and for the industries who establish quality assurance plans including in particular the search of critical contamination points in the processes.
Consequently quite a number of public or private laboratories carry out each year many thousands of chemical and microbiological analysis in the fields of foodstuffs, environment or health.
Inter-laboratory studies have clearly showed that the laboratories generally worked with quite a good precision, but important variations existed between the results obtained from different laboratories.
Thus, excess results may be observed in laboratories having badly adjusted stoves, whereas default results are observed in laboratories having culture media of a poor quality.
Such erroneous results may have an great economical impact upon public health. The excess results may lead to refuse wrongly a product batch, to programme unnecessarily sanitizing operations to improve a beach quality or to disturb people by prohibiting tap water consumption.
In contrast, default results may incur a risk for the consumers by authorizing sales of contaminated products, distribution of poorly disinfected water or bathe in polluted water.
To secure reliable measurements, the checking laboratories have been asked to be accredited. Initially such accreditation only defined obligations of means (qualified personnel, adapted rooms, maintenance of measurement apparatus, control of raw materials and writing of the analytical procedures). At the present time, it also requires obligations of results. Such a new requirement imposes the implementation of a quality system including internal controls and participation to inter-laboratory tests.
For controlling the analytical chains internally and organize inter-laboratory tests, it is imperative to use reference materials. Such reference materials must be stable in time and should allow to reconstitute homogenous control samples containing an exact amount of the product to be dosed.
In chemistry, such reference materials have been existing for many years. In contrast, in the microbiological field, it is particularly difficult to preserve exact amounts of micro-organisms. In fact, the number of micro-organisms may either increase, if the preservation media enables their multiplication during manufacture, transport or storage, or decrease, if they die during manufacture, transportation or storage or at the time of the reconstitution of the control sample before use.
Methods for preserving micro-organisms, such as lyophilization and cryoconservation, have been already described in the all. However, such methods lead upon the conditioning step to high mortality rates amongst the micro-organisms being preserved, and consequently do not allow to master accurately the final quality of the surviving micro-organisms.
Thus, two patents appealing to a rude freezing method in liquid nitrogen do not describe the preservation of bacteria or micro-organisms and do not address to the problem of the quantitative dosages.
U.S. Pat. No. 5,364,756 discloses a method of cryoconservation for eucalyote cells. A suspension of such cells is prepared in a buffer comprising cryoprotecting agents, and then the solution is nebulizated with ultrasounds so as to form microdroplets that are rapidly cooled and dried.
U.S. Pat. No. 5,405,616 relates to the preservation of pharmacologically active molecules. The particles comprising such molecules are predominantly made of a skeleton-forming water-soluble hydrophilic macromolecule. Various proteins are mentioned, mainly proteins from vegetal origin.
Exact amounts of micro-organisms may be obtained from naturally or artificially contaminated samples. However, the preservation of such samples cannot go beyond 24 hours and requires a lower temperature than 10xc2x0 C.
Exact amounts of various bacteria are also obtained after freezing in a medium containing serum and inositol (1993 Peterz and Steneryd, J. of Appl. Bacteriol., 74, 143-148) or skimmed milk (1994 Schijven, Havellaar and Bahar, Appl. And Environ. Microbiol., 60, 4160-4162). It seems however that such frozen bacterial suspensions are not stable beyond three months for the first type of preparation and one year for the second one. Moreover, they require very demanding transportation conditions (short deliveries and maintenance of the temperature below xe2x88x9270xc2x0 C.). Finally their stability in case of successive thaw-freeze has not been demonstrated.
Presently only atomization manages to conciliate the preservation, stability and transportation constraints with the requirement of an exact amount of micro-organisms.
Suspensions of Bacillus cereus in concentrated milk atomized and encapsulated in gelatine have been used as reference materials after transportation at room temperature (Paul H. In""t Veld, 1993, Int. J. of Food Microbiol., 20, 23-36).
However, such technique is difficult to be implemented, because it requires a dissolution of the gelatine in a reconstitution medium maintained a 37xc2x0 C. Moreover, some species like Aeromonas hydrophila, Pseudomonas aeruginosa and Campylobacter jejuni cannot be preserved stably by atomization. Such a process is not recommended either for preserving respiratory tract pathogens being transmissible with aerosols like Legionella pneumophila. Finally the reference materials prepared by atomization have a high cost.
It appears thus from the art that no process was known which would be easy to be carried out and cheap allowing to preserve stably exact amounts of micro-organisms.
The Assignee has solved this problem by finding a particular composition being able to hold viability of micro-organisms.
The present invention thus relates to a composition for preserving predetermined and reproducible amounts of micro-organisms comprising in combination efficient amounts of at least one material being able to form the skeleton of lens-shaped pellets and at least one saturating material as well as micro-organisms.
For the present invention it is meant by reproducible amounts of micro-organisms variations of the ratio between two measurements comprised, in 95% of the cases, between 0.25 and 4, more preferably between 0.5 and 2.
Said composition comprises from about 10 to 60% of substances being able to form the skeleton of the lens-shaped pellets. Preferably a mixture of albumin and starch is used containing from about 20 to 40% albumin and from 2 to 5% starch (in total weight of the composition). After freezing and drying, these molecules form a highly porous and simultaneously mechanically stable skeleton that is dissolved rapidly in water.
Advantageously albumin belonging to such a composition is ovalbumin. Ovalbumin may appear in particular as an egg white preparation. Egg white is a sterile medium rich in protecting proteins within which it is possible to disperse the micro-organisms homogeneously. It may be however any other albumin (bovine albumin serum) or any protein having the same function.
Starch can be any type of starch and, in particular, natural as well as modified starches, dextrans, dextrins and maltodextrin. It can be substituted by any other hydrophilic macromolecule, particularly vegetal proteins or the hydrolysates thereof, collagens, gelatins, elastin hydrolysate or mixtures of above-mentioned substances.
Said composition also comprises from about 40 to 90% of a saturating substance. The saturating substance may be formed with one or more mixed salts or sugars. Such salts or sugars may be added as powder, brine or syrup. By using saccharose, preferably from about 60 to 80%, the composition has a lower water activity than 0.9. Consequently, the cellular damages occasioned by freezing and drying are limited and the development of micro-organisms is prevented in particular upon any transportation at room temperature.
According to one embodiment of the invention, the composition contains one or more types of micro-organisms. They can be strict anaerobic bacteria, aero-anaerobic or strict aerobic bacteria, psychrophilic bacteria, mesophilic or thermophilic bacteria, halophilic bacteria, enterobacteria, streptococci, staphylococci, pathogenic bacteria (Salmonella, Campylobacter, Yersinia, Listeria, Pseudomonas aeruginosa, Aeromonas, Vibrio, etc.), yeasts or moulds or fungi, bacteriophages or viruses, or protozoal cysts.
Advantageously, the present composition includes from 102 to 1011, preferably from 102 to 109 micro-organisms per gram. Such a composition may be advantageously presented as pellets and in particular as lens-shaped pellets having a diameter in a range of 1 to 10 mm.
Such pellets have advantageously a mass from about 1 to 250 mg, preferably from about 2 to 100 mg, more preferably from 10 to 25 mg.
The pellets according to the present invention can be advantageously obtained with a manufacturing process comprising the following steps of:
a) incorporating micro-organisms into the skeleton material,
b) reducing water activity by adding progressively the saturating substance,
c) shaping the pellets, and
d) drying the pellets under vacuum and at a temperature lower than about xe2x88x9210xc2x0 C.
Preferably the mixture is carried out as follows:
a) mixing albumin and micro-organisms,
b) adding starch, and then
c) adding saccharose.
Various drying modes are to be envisaged. Advantageously pellet drying is carried out in a desiccator in a period from about 12 hours to 10 days.
In view of an optimal stability, i.e. over a period of more than 12 months, the pellets may be stored at xe2x88x9270xc2x0 C. in the presence of a dehydrating bag. They can however be preserved 3 months at xe2x88x9220xc2x0 C. and 4 days at room temperature, making thus for example their transport easier since no particular and complexed transport condition is required.
A reconstitution medium convenient for a use in the present invention should limit at a maximum the osmotic shock upon the pellet dissolution. A 23 g/l synthetic sea salt solution is recommended as a reconstitution medium, since it presents a higher recovering level of the micro-organisms than the diluents usually used in microbiology such as Ringer, saline peptone or distilled water. Such a solution may be the one sold by Aquarium Systems (MENTOR, Ohio, USA) under the name Instant Ocean, or the DSM medium sold by SANOFI PASTEUR (Marnes la Coquette, France).
Pellet dissolution should be effected at room temperature. If the sample is not analyzed within half an hour after the reconstitution, it is to be recommended to maintain it in melting ice so as to guarantee a good stability.
Such pellets containing micro-organisms stable over time, homogeneous and able to be reconstituted as a suspension reproducibly, i.e. with amounts varying weakly from one test to another one, constitute actual reference materials particularly adapted for checking the reliability of measurements (internal and external quality control) in the bacteriology field for waters, drinks and foodstuffs generally, in pharmacy, cosmetics and environment.
This type of reference material may also be used advantageously for xe2x80x9cchallenge testsxe2x80x9d in the foodstuffs field. For such a specific use, the pellets contain one or more micro-organisms. Pellets may be directly introduced into the product to be tested (alu-dish, salad bag, cooked dish, etc.). The products are then put in real preservation conditions and the progress of the contamination introduced quantitatively into the products is monitored according to the usual numbering procedures.
More generally, this new type of reference material may be used for the quantitative microbiological analysis:
checking the presence/absence of micro-organisms,
checking the fertility of culture media,
checking the efficiency of antibiotics, bactericide or bacteriostatic substances,
checking sterilization (ultraviolet, chloration, ozonization, filtration, etc.).
According to another aspect of the invention, the pellets containing at least one type of micro-organisms may be advantageously used in specific products as starting agents for seeding the species so as to master a crucial microbiological parameter interfering in the fermentation process.
Thus, pellets containing yeasts, such as for example S. cerevisae, S. calbergensis, S. ellipsoidus, may be used to produce bread, high and low pressure beers, wine and other alcohols.
Pellets containing lactic bacteria may advantageously be used to produce fermented milks and yoghurt as well as in the pharmaceutical industry to produce products convenient for re-seeding intestinal flora.
Pellets containing activated fungal spores may be used directly or after dilution to a desired content of micro-organisms, in the foodstuffs field, particularly for cheese or salted food products. Said compositions may for example be spread or incorporated into the products to be converted, such as cheeze of salted food products.
Thus, pellets containing specific bacterial species, such as for example Rhizobium, Pseudomonas, Bacillus, Arthrobacter, Serratia and Azospirillum, may be used in agriculture and in the environment industry.
The present invention will be now illustrated without being limited by the following examples.

Composition for forming a dried lens-shaped pellet comprising albumin, starch, microorganisms and sugar and/or salt


A preparation of metallic salt of ethercarboxylic acid in a pure form by restraining the formation of fumaric acid likely to occur when maleic acid and/or maleic anhydride react with oxycarboxylic acid. The ethercarboxylic product is a useful chelating agent.

The present invention relates to a process for producing metallic salt of ethercarboxylic acid (hereinafter referred to as "ethercarboxylic product") useful as an organic chelating agent. More particularly, the present invention relates to the preparation of ethercarboxylic product in a highly pure form by restraining the formation of fumaric acid likely to occur in the manufacture of the product when maleic acid reacts with oxycarboxylic acid.
Ethercarboxylic products are known for their strong chelating ability by which metallic ions are confined in rings; particularly tetrasodium tartrate monosuccinate (I) and hexasodium tartrate disuccinate (II) are known as useful detergent builders, the formulas of these two salts are respectively as follows: ##STR1##
The production of metallic salt of ethercarboxylic acid is suggested in many literatures. U.S. Pat. Nos. 4,058,560, 4,188,493 and British Patent No. 1,389,732 disclose processes for manufacturing salts of carboxymethyloxy succinic acids. EP No. 236,007 discloses the preparation of salts of oxydisuccinic acid, and U.S. Pat. No. 4,663,071 and EP No. 266,723 disclose the preparation of salts of tartaric monosuccinic acids and tartaric disuccinic acids with the use of maleic acid and tartaric acid, and the adaptation of them for detergent builders. In common with these known processes, oxycarboxylic acids such as glycolic acid, malic acid, tartaric acid or tartronic acid, and maleic acid are reacted in the presence of zinc and/or alkaline earth metal, to which alkali metal hydroxide is added until the pH value is raised to 10 to 13. The reaction takes place at a concentration of 20 to 60 wt % organic acid salt, at a temperature of 50.degree. to 120.degree. C. over a period of 0.5 to 10 hours. In this way metallic salt of ethercarboxylic acid is obtained. Then alkali metal carbonate is added to remove the zinc and/or alkaline earth metal as zinc carbonate and/or alkaline earth metallic carbonate. Being free from the zinc and/or alkaline earth metal, the alkali metal salt of ethercarboxylic acid becomes useful as a detergent builder.
Under the known processes mentioned above, insoluble organic acid salts are produced in the reaction between the carboxylic acids and the metals. On the other hand, as the concentration of these organic acid salts becomes high, the ethercarboxylic product reaches a state of equilibrium for a shorter period of time, thereby securing a high yield of the product. However, if the industrial-scale process is carried out at such a high concentration from the start to the end, the viscosity becomes high because of a large amount of insoluble substances, thereby making it difficult to stir the mixture. In addition, heat is generated by neutralization between the acid and the base. There arises a need for dissipating the heat. In this way the process encounters with the difficulty in stirring and the necessity of dissipating the heat, which obstructs the smooth prosecution of the process. The known processe is carried out at a reduced concentration so as to secure the smooth stirring and quick heat dissipation even though the yield is sacrificed.
Commercial oxycarboxylic acids such as malic acid, glycolic acid and tartaric acid are generally on sale in solid. To put them in industrial use, they are diluted with water before starting an addition reaction. However oxycarboxylic acids are generally manufactured in aqueous solution. If they are used in aqueous solution, it will be unnecessary to concentrate the aqueous solution and then dry into solids.
One proposal is to supply the material in the form of a slurry, and to concentrate it to the extent that the stirring and heat dissipation are not prevented. Then the addition reaction is carried out. However, it has been found that the concentrating of the slurry involves the formation of fumaric acid, which is difficult to react with oxycarboxylic acids. This leads to the low yield of ethercarboxylic products, and also makes it difficult to obtain them in a pure state. There seems to be at least two reasons for the formation of fumaric acid; one is that maleic acid is subjected to cis-trans isomerism and transform into fumaric acid, and the other is that the metallic salts of ethercarboxylic acid is subjected to a reversible reaction, thereby decomposing into the original oxycarboxylic acid and maleic acid. About 50% of unsaturated acids becomes fumaric acid while the decomposition proceeds.
In the addition reaction mentioned above zinc and/or alkaline earth metal are normally added, but these substances produce zinc salt of ethercarboxylic acid and/or alkaline earth metallic salt. However, alkali metal salts of ethercarboxylic acid are known as useful detergent builders, but zinc salt and/or alkaline earth metallic salt of ethercarboxylic acid are not useful as detergent builders. On the other hand, all these metallic salts are useful as chelating agents, which captures heavy metals. As a result, the present invention aims at utilizing the chelating ability of alkali metal salt, zinc salt of ethercarboxylic acid and/or alkaline earth metallic salts.
The ethercarboxylic products find many applications, and as an example the manner of using it as a detergent builder will be described:
As described above, zinc salts and/or alkaline earth metallic salts are not useful as detergent builder. To remove such useless substances a special process is required. However, if zinc and alkaline earth metals are removed in the form of salts, it leads to the low yield of ethercarboxylic product. As a result, it is necessary to substitute zinc salt and/or alkaline earth metal with alkali metal. To substitute these metals, alkali metal carbonate and/or bicarbonate is added to zinc salt and/or alkaline earth metallic salt of ether carboxylic acid. The zinc carbonate and/or alkaline earth metallic carbonates are removed as sediments by decanting or any other similar method. However, the removal of these useless substances unavoidably involves the discharge of ethercarboxylic acid in the form of alkali metal salt. This not only leads to the low yield of ethercarboxylic product but also to pollution problems and waste of resources.

Process for producing metallic salt of ethercarboxylic acid

Nippon Shokubai Kagaku Kogyo Company, Ltd.


A gearbox for use in an electric power assisted steering system of the kind in which a motor is connected to a portion of a steering mechanism through the gearbox, comprises a housing, a worm gear carried by a worm shaft and a gear wheel carried by an output shaft, the worm shaft being supported relative to the housing by a tail bearing assembly, in which the bearing assembly is located relative to the gearbox housing by a bearing carrier, the carrier comprising a bearing carrier part which is fixed to the bearing assembly and a reaction part which is fixed to the gearbox housing, the bearing carrier part being connected to the reaction part by at least two connecting elements, the two elements being spaced apart so that they act, in effect, with the bearing carrier part and the reaction part to form a parallelogram linkage that enables the bearing carrier to be relatively free to move relative to the reaction part in one direction whilst being relatively restrained from movement in the two directions orthogonal to that direction.

This invention relates to improvements in electric power assisted steering apparatus and in particular to gearbox assemblies for use in electric power assisted steering systems of the kind which incorporate a worm and wheel gear assembly for transferring torque from an electric motor to a steering shaft or output shaft operatively connected thereto.
It is known to provide a power steering system for a vehicle comprising an electric motor having a stator and a rotor, an input shaft operatively connected to the rotor and adapted to rotate therewith, an output shaft associated with a steering shaft, and a gearbox adapted to transfer torque from the input shaft to the output shaft in response to a measure of the torque in the output shaft as produced by a torque sensor. The motor is typically operated to apply an increasing torque to the output shaft as the measured torque increases, thus applying assistance that helps reduce the effort needed to steer the vehicle.
In a simple arrangement the input shaft carries a worm gear, and the output shaft carries a wheel gear. The teeth of the worm and wheel intermesh to transfer the torque. This system is simple and robust whilst providing relatively high gearing with a low component count. There exists, however, a problem in such gearboxes with noise and vibration due to incorrect meshing between the worm and wheel.
A worm and wheel gearbox, for an Electric Power Steering system, having a fixed centre distance between the axes of the worm and gear wheel is prone to rattle when transmitting zero or low torque if there is excessive clearance between the gear teeth of the worm and those of the gear wheel. Alternatively, it is prone to having high friction if there is forced meshing between the worm and wheel due to interference between the teeth.
A solution to this problem is taught in the applicant's earlier Patent EP 1 087 883 B 1. The document discloses a gearbox assembly that includes a pivoting means at or near to the centre of the wormshaft main bearing, which is at the motor end, in order to allow the wormshaft axis to rotate through small angles about its nominal position in the plane of the gearwheel, typically by less than plus/minus 0.5 degrees. The outer race of the tail bearing is biased towards the gearwheel by a spring with sufficient force to ensure that the worm teeth remain in dual-flank contact with the gear teeth for levels of gearbox output torque of zero to, typically, around 4 Nm. This removes backlash between the worm and gear teeth at low torques and thereby prevents rattle.
The outer race of the tail bearing is usually guided so that it can move only in the plane of the gear wheel. The guidance is provided by a component which is inserted into the gearbox housing and which has a short slot along which the outer race of the bearing can slide, usually by a maximum of around plus/minus 0.5 millimetres. The said guiding component, sometimes referred to as the "Oval Ring" has to be designed so that it itself does not become another source of rattle. It must therefore lightly grip the opposite sides of the tail bearing's outer race without causing enough friction to prevent its ability to slide fairly freely. It must, at the same time, prevent significant deflections of the bearing normal to the gear plane due to the effects of the gear tooth helix angle. These are generally conflicting requirements needing a highly non-linear type of lateral compliance to achieve satisfactory performance.
The oval ring may also incorporate a soft-stop which will prevent an audible impact when, at higher torques, the tail bearing is forced to one end of the slot by the gear tooth separation forces. Whilst that arrangement works well it can result in a small amount of unwanted lateral movement of the bearing together with too much frictional restriction of its movement along the slot.

Gearbox for electric assisted steering apparatus


A method for the estimation of the motion of electronic picture points, in the plane of the picture, by means of fast, convergent and adaptive processing, notably in order to enable subsequent, efficient processing, by sub-sampling, of the picture sequence without harming the psycho-visual quality of the picture reconstructed from the sub-sampled picture. To each electronic picture point, there is assigned a displacement vector, computed according to a WALKER and RAO type of algorithmic process of prediction/correction, the predicted value of motion of the current point being the value of the original displacement vector associated with a point of origin of the preceding picture, so that said current point is the approximate projection of said point of origin along said original displacement vector.

1. Field of the Invention
The field of the invention is the analysis and encoding of electronic pictures and, more particularly, the analysis of the motion of the points of electronic pictures of this type.
2. Description of the Prior Art
In the specific example which shall be described in detail below, the method according to the invention can be applied to the analysis of high definition picture sequences, designed to be transmitted through a channel with a limited throughput. A preferred application of this type is the transmission of high definition television on MAC channels.
However, the method of the invention can also be used in any system analyzing a sequence of pictures (for example in robotics, target-tracking, searching for spatial and/or temporal parameters, etc.).
The method according to the invention is designed to be part of a picture processing chain and to form a link in the analysis of the displacement speeds of picture points in the picture plane.
An analysis of this type is valuable in a great many ways.
For the transmission of picture sequences in a channel with limited throughput, the processing of pictures is designed to reduce the volume of data transmitted, in such a way that:
at emission, a sub-sampling operation is performed, the sub-sampling data being accompanied by "assistance data" transmitted conjointly via the data channel; PA1 at reception, a reverse operation is performed, consisting in the use of the assistance data and the sub-sampled signal to restitute a high definition signal. PA1 limits related to the algorithmic method chosen; PA1 limits related to the recursive design of most of the algorithms; PA1 limits related to the choice proposed for the starting hypothesis of the estimation algorithms. PA1 said current displacement vector of a current point at the instant t is computed according to an algorithmic prediction/correction process in which a prediction value of motion is taken as a starting hypothesis for computation, said predicted value being subsequently corrected within the process according to a method of correction by optimization of criteria, PA1 and wherein PA1 said predicted value of the motion of the current point is the value of the original displacement vector associated with a point of origin of the picture at the instant (t-1), said current point being the approximate projection of said point of origin along said original displacement vector. PA1 said method achieves, in parallel, at least two computations of motion estimation using two predicted values of motion of the current point, said predicted value being chosen from among the following values: PA1 and wherein PA1 said method chooses the estimation of the speed vector according to a method of decision by optimization of criteria.
In this scheme, the picture point motion estimation step, according to the present invention, occurs, for example, prior to the sub-sampling operation. The purpose of motion estimation, then, is to create a spatial-temporal data base, wherein the pieces of data represent the motional activity of the points, in the plane of the picture and in time. These are pieces of data which will make it possible to determine the most appropriate processing operation to accomplish the compression of data by sub-sampling.
An already known method in the field of data compression processing operations, with picture motions taken into account, is the one for the analysis of structures in spatial-temporal sub-sampling of an HDTV signal with a view to its transmission in an MAC channel as described in the proceedings of the HDTV 87 colloquium, Ottawa, 4th to 8th October, 1987, Vol. 1, pp. 6.2.1 (P. BERNARD, M. VEILLARD, CCETT). In this known method of analysis, each picture in the sequence is divided into zones, and each zone systematically undergoes three parallel processing operations in three distinct linear filters. Each filter provides for a different sub-sampling filtering operation, corresponding to a preferred filtering operation for still (motionless) pictures, pictures in moderate motion and pictures in fast motion, respectively. The outputs of the filters are then compared with the original source, and the best type of filtering is selected to determine the effectively transmitted, compressed signal.
A battery of linear filters of this type has the drawback of enabling only a limited choice among only three types of sub-sampling filtering operations, without the possibility of making the filtering operation more specifically to each particular feature of the zones processed. It has been noted, in particular, that there is a heterogeneity in the definition of distinct zones within one and the same picture, as well as low-level performance by this system in the processing of slow motions. This problem appear very clearly for example, in a very troublesome way for the viewer, when a slow motion is stopped or, again, when a still object is put into motion. In these instances, there is a sudden transition, from a blurred definition of the moving object to a maximum definition of a still object in the former case, and vice versa in the latter case.
A more refined, prior art approach to the problem of the encoding of a sequence of pictures consists, then, in making an a priori estimation of the motion in the picture sequence.
In this respect, T. S. HUANG ("Image Sequence Analysis: Motion Estimation" in Image Sequence Analysis; Ed. T. S. HUANG, Springer Verlag 1981) identifies three distinct methods, namely the FOURIER method, the "correspondence" or block matching method and the method using spatial or temporal gradients. The former two methods have a certain number of drawbacks. The FOURIER method is associated with a problem of phase indeterminacy and assumes uniformity of the picture background. The block-matching method appears to be likely to entail complex operations for processing the signal, for which attempts at simplification appear to cause risks of divergence in the processing algorithm.
Among methods using spatial and temporal gradients, a number of proposed algorithms are known: LIM, J. O. and MURPHY J. A., "Measuring the Speed of Moving Objects from Signals", IEEE Trans. on Com., April 1975, pp. 474-478; NETRAVALI, A. N., ROBBINS, J. D. "Motion Compensated Television Coding: Part I", BSTJ, Vol. 58, No. 3, March 1979, pp. 631-670; SABRI, S., "Motion Compensated Interframe Prediction for NTSC Color TV Signals", IEEE Trans. on Com., Vol. COM 32, No. 8, August 1984, pp. 954-968; ROBERT, P. "Definition d'un Schema de Codage Multimodes avec Compensation de Mouvement pour les Sequences d'Images de Television" (Definition of a Multimode Encoding Scheme with Motion Compensation for Television Picture Sequences), IRISA thesis, November 1983; LABIT, C. "Estimation de Mouvement dans une Sequence d'Images de Television" (Estimation of Motion in a Television Picture Sequence), IRISA thesis, Rennes, February 1982; WALKER, D. R., RAO, K. R. "New Technique in Pel-Recursive Motion Compensation" ICC 1984, Amsterdam, pp. 703-706.
These known estimation methods come up, in fact, against three types of limits:
With respect to the limits for algorithmic methods, the known methods can essentially be classified under two groups: algorithms that seek the components of the speed vector attached to a block of pictures (block matching) and algorithms that seek the components of the speed vector attached to a picture point. The criteria used to choose either of the algorithmic methods are essentially related to the complexity of the processing operations used, and to the psycho-visual perception of the relative efficiency attached to each technique.
For the method according to the invention, it has been chosen to work preferably with a pel-recursive motion estimator and, preferably but not restrictively, with the motion estimator as described by WALKER and RAO. The reasons for this choice, which are part of the inventive step that has resulted in the method, shall appear below.
It will be noted that the method nevertheless applies equally well to the block motion estimation, each block being capable of being represented by a single representative, which may be vectorial as the case may be.
The second limit is related to the recursive character of most of the known algorithms. Recursivity has the drawback of requiring several computation loops to estimate the motion of a point. These operations are, therefore, necessarily sequential, since the order n estimation can be assessed only after the order n-1 estimation is known. At current TV frequencies, this method is incompatible or, at the very least, disadvantageous.
Finally, a third type of limitation is related to the initialization mode presently recommended for known motion estimation algorithms, and essentially for estimation algorithms known as pel-recursive algorithms. Moreover, these initializing modes are generally related to the algorithmic technique and to the mode of recursivity chosen. From this point of view, it is possible to distinguish two main techniques of recursion corresponding to an improvement in point motion estimation, depending either on a spatial interpolation (see, for example, A. N. NETRAVALI, J. D. ROBBINS, already cited; P. ROBERT, C. CAFFORIO, F. ROCCA "Time/Space Recursions for Differential Motion Estimation", 2nd Internat. Tech. Symp. on Optical and Electro Optical Applied Science and Engineering, Cannes, December 1985; B. K. P. HORN, B. G. SCHUNCK, "Determining Optical Flow", Artificial Intelligence, Vol. 17, pp. 185-203, 1981; W. ENKELMANN, "Investigations of Multigrid Algorithms for the Estimation of Optical Flow Fields in Image Sequences", Workshop on Motion: Rep. and Analysis, IEEE, May 1986, Charleston), or a temporal interpolation (Y. NINOMIYA, Y. OHTSUKA, "A Motion Compensated Interframe Coding Scheme for Television Pictures", IEEE Transactions, Vol. Com. 30 , No. 1, January 1982, pages 201-211; R. PAQUIN, E. DUBOIS "A Spatio-Temporal Gradient Method for Estimating the Displacement Vector Field in Time-Varying Imagery", Computer Vision, Graphics and Image Process, Vol. 21, 1923, pp. 205-221). The temporal interpolation is more especially suited to the processing of still picture sequences whereas the spatial interpolation is essentially satisfactory for fast picture sequences. By contrast, the available laws are ill-suited to slow motions for which they show high degree of directional streaking, causing substantial and incoherent pollution in operations for the processing of picture encoding.

Multi-predictive method to estimate the motion of the points of an electronic picture


A vehicle air intake assembly is disclosed. The assembly includes a housing, a conical filter, and optionally may also include an inlet cowl. The housing and filter decrease in diameter from an inlet or distal end toward a proximal or outlet end. The shape of the housing guides the air into a smaller cross-sectional area and induces a Venturi effect on the airflow passing through the housing and filter. The housing decouples the filter from an engine inlet and the proximal or outlet end of the housing is sized so as to attach to the engine inlet and provide a smooth transition for the air leaving the housing and entering the engine inlet.

Motor vehicles are equipped with an air filter system that filters air destined for the engine. Conventional air filter systems use a cuboidal filter enclosed by a cuboidal housing. This type of air filter cause the air to transition from a rectangular filter housing outlet to a cylindrical pipe inlet. Such an abrupt transition in geometrical shape causes the airflow to be turbulent, and hence causes engine "choking," particularly at high RPM.
More recent, aftermarket intake systems use a conical filter in place of the conventional rectangular filter. The conical filter in these aftermarket systems is directly connected to the inlet pipe of the engine and is oriented such that the smaller diameter of the conical filter is upstream and the larger diameter is downstream with respect to airflow into the engine. Moreover, the larger diameter of the conical filters conventionally has a neck attached to the filter to allow the filter to be connected to piping, such as engine air inlet piping.
The conventional air intake systems, whether cuboidal or conical, do not properly shape the airflow directed into the engine or carburetor inlet. For example, in conical filters positioned with their larger diameter adjacent the engine inlet, airflow must negotiate through an abrupt change in geometrical shape from the filter material through the smaller diameter neck that leads to the engine inlet. This causes turbulent airflow in the filter and inhibits the airflow from increasing in velocity as the air traverses the filter and enters the engine inlet. These and other deficiencies exist.

This patent is subject to a terminal disclaimer.