A system and method for determination of error parameters for performing self-calibration and other functions in a transducer. The method utilizes the minimum and maximum values of the output signals of the transducer. To obtain these values, the output signals are measured at various times according to the sample timing, as the read head is scanned relative to the scale. The offset for each phase is determined to be equal to the average between the maximum and minimum voltages. The signal amplitudes are equal to the difference between the maximum and the minimum voltages, divided by two. By comparing the amplitude for each phase, the amplitude mismatch is found. The phase relation error may be determined by first removing the amplitude mismatch and the offset errors from each phase, and then comparing the relative amplitudes of the two signals at a given point in relation to what they ought to be with no phase relation error. The described method provides a fast calibration method which requires a minimum amount of data, and which can be automatically run in a background mode without inhibiting normal transducer operation.

This invention relates to position transducers, and more specifically, to a system and method for determination of error parameters for performing self-calibration and other functions in a position transducer system.
Various movement or position transducers for sensing linear, rotary or angular movement are currently available. These transducers are generally based on either optical systems, magnetic scales, inductive transducers, or capacitive transducers.
In general, a transducer may comprise a read head and a scale. In an example of a 2-phase system, the transducer outputs two signals S1 and S2 that vary sinusoidally as a function of the position of the read head relative to the scale along a measuring axis. In one common concept for transducers, the signals S1 and S2 are intended to be identical except for a quarter-wavelength phase difference between them. The transducer electronics use these two signals to derive the instantaneous position of the read head relative to the scale along the measuring axis.
Ideally, the signals S1 and S2 are perfect sinusoids with no DC offsets, have equal amplitudes, and are in exact quadrature (i.e., a quarter-wavelength out of phase relative to each other, also referred to as xe2x80x9corthogonalxe2x80x9d herein). In practice, the signals S1 and S2 have small DC offsets, their amplitudes are not equal, and they have some orthogonality error. In addition S1 and S2 may have distorting spatial harmonic components. In addition, the transducer electronics can introduce additional errors such as offset, gain, and non-linearity errors.
In many practical transducers, the dominant sources of errors are offsets, and amplitude mismatches and phase errors between the phases. These errors are shown in the following equations for the case of a 2-phase system.                               S          1                =                              C            1                    +                                    V              1                                    sin                                      xe2x80x83                                                                  2                                                  xe2x80x83                                                π                            λ                                                  (                              x                -                                  φ                  1                                            )                                                          (        1        )                                          S          2                =                              C            2                    +                                    V              2                                    cos                                      xe2x80x83                                                                  2                                                  xe2x80x83                                                π                            λ                                                  (                              x                -                                  φ                  2                                            )                                                          (        2        )
In the above equations, x is a position, and xcex is a wavelength to the transducer output. The terms C1 and C2 produce offset errors. The terms V1 and V2 (if V1xe2x89xa0V2) produce amplitude mismatch errors. The terms xcfx861 and xcfx862 (if xcfx861-xcfx862xe2x89xa00xc2x0) produce phase mismatch errors, that is, phase relationship errors.
Alternatively, some transducers utilize a 3-phase system. The equations for a 3-phase system are shown below.                               U          R                =                              C            0                    +                                    A              0                                    sin                                      xe2x80x83                                                                  2                                                  xe2x80x83                                                π                            λ                                                  (                              x                -                                  φ                  0                                            )                                                          (        3        )                                          U          S                =                              C            0            xe2x80x2                    +                                    A              0              xe2x80x2                                    sin                                      xe2x80x83                                                                  2                                                  xe2x80x83                                                π                            λ                                                  (                              x                +                                  λ                  3                                -                                  φ                  0                  xe2x80x2                                            )                                                          (        4        )                                          U          T                =                              C            0            xe2x80x3                    +                                    A              0              xe2x80x3                                    sin                                      xe2x80x83                                                                  2                                                  xe2x80x83                                                π                            λ                                                  (                              x                -                                  λ                  3                                -                                  φ                  0                  xe2x80x3                                            )                                                          (        5        )
In the above equations, the terms C0, C0xe2x80x2, and C0xe2x80x3 produce offset errors. The terms A0, A0xe2x80x2, and A0xe2x80x3 (if they are not identical) produce amplitude mismatch errors. The terms xcfx860, xcfx860xe2x80x2, and xcfx860xe2x80x3 (if not all equal) produce phase mismatch errors.
One method for addressing errors such as those shown above is to calibrate the transducer. Calibrating the transducer and compensating for these errors requires determining or comparing the DC signal offsets, the amplitudes of the fundamental signals, the phase error between the fundamental signals, and insuring that they are adjusted or compensated to be equal. For further error compensation, the amplitudes of the harmonic components must also be considered.
One commonly used prior transducer calibration method is the xe2x80x9cLissajousxe2x80x9d method. The Lissajous method typically comprises inputting two nominally orthogonal read head signals to an oscilloscope, to drive the vertical and horizontal axis of the oscilloscope. The read head is continually scanned relative to the scale to generate changing signals. The oscilloscope display is observed, and the read head is physically and electronically adjusted until the display indicates a xe2x80x9cperfectxe2x80x9d circle, centered at zero on both axes. Under this condition, the amplitude, orthogonality, and offset of the two signals are properly adjusted.
The Lissajous method assumes that the two signals are both perfect sinusoids. Typically, there is no adjustment for harmonic errors which can distort the circle, as it is hoped that these are made insignificant by fixed features of the transducer design and assembly. The Lissajous method is well known to those skilled in the art, and has been performed by sampling the two signals with computer-based data acquisition equipment. However, to use this method in the case of a 3-phase system, the signals must generally to be converted to orthogonal signals before processing. Many three-phase systems either lack such signals, or access to such signals is either inconvenient or costly, making the Lissajous method inappropriate for many 3-phase transducer systems and products.
Alternatively, it has also been common to accept any transducer errors due to imperfect amplitudes, orthogonality, harmonics, and offsets, and to use an external reference, such as a laser interferometer, to accurately correct position errors from the read head at the system level, at predetermined calibration positions relative to the scale.
Position transducers typically require initial factory calibration, and periodic calibration or certification thereafter. In both cases, there is a cost for the associated equipment and labor. When the transducer is located in a remote location, it is difficult to set up the external data acquisition equipment and/or accurate external reference required for calibration. As a result, the transducer often has to be transported to another site or shipped back to the factory for calibration. This results in long downtime and increased costs.
Even in cases where the transducer does not have to be transported for calibration, the special tools and increased time required to set up the external display and/or reference result in increased costs and downtime. Thus, calibration and recalibration is often minimized or avoided, in practice. Since most practical position transducers are sensitive to variations during production, installation, and use, measurement errors normally increase in the absence of calibration, and in the periods between recalibration.
One example of a self-calibration method for an inductive position sensor is illustrated in U.S. Pat. No. 5,742,921. However, the method of the ""921 patent is closely tied to the operation of an associated motor, teaches positioning the transducer in order to acquire the desired data, and emphasizes calibration based on a signal range which is of little or no importance in certain implementations.
Another exemplary self-calibrating position transducer system that better-addresses some of the issues outlined above is illustrated in U.S. Pat. No. 6,029,363, which is commonly assigned and hereby incorporated by reference in its entirety. The method described in the ""363 patent samples two orthogonal output signals of the transducer at a plurality of evenly spaced positions within the one scale period, using the transducer itself as a position reference. The method then determines calibration values for the DC signal offsets, the amplitudes and non-orthogonality of the fundamental signals, and the amplitudes of the signal harmonic components using Fourier analysis techniques. Finally, the method corrects the signals using the determined calibration values. In summary, the method of the ""363 patent determines the error parameters by: (1) measuring the output voltages of the transducer as a function of a known position, and (2) analyzing the data using Fourier series techniques to derive the offset, amplitude, and phase mismatch parameters.
The method of the ""363 patent is effective for addressing many of the calibration issues described above, including the ability to compensate spatial harmonic errors. However, the method also introduces inconvenient data acquisition complexity and other constraints which reduce the convenience of the method in many practical situations. The present invention is directed to an alternative method for determination of error parameters for performing self-calibration and other functions without an external position reference in a transducer.
Most prior art position transducer systems do not include any way to conveniently identify and correct the various errors described above, outside of a permanent factory calibration environment. Furthermore, prior art methods have resulted in system error corrections that are fixed at the time of calibration, with no convenient way to adjust the corrections for subsequent alignment changes or aging of the transducer components. The present invention is directed to a system and method for determination of error parameters for performing self-calibration and other functions without an external position reference in a transducer. In various embodiments, the systems and methods of this invention uses a min-max method that involves measuring the transducer output signals as a function of time and does not require knowledge or recording of known positions. Thus, special tools or instruments are not required to calibrate the position transducer. In addition, the method is simple and fast enough that calibration/re-calibration or a related self-test operation may be performed continuously as a background task while the position transducer is operating. Thus, the system can keep the position transducer continually calibrated without interfering with the transducer""s normal operation.
In one embodiment, the method of this invention samples the output signals at a relatively high rate. The read head is moved relative to the scale at a speed v, along with an initial acceleration a. It is not necessary to know either v or a, but it is preferred that they be lower than a predetermined maximum value. The scan may be continued over a distance of several wavelengths. In this manner, the output signals are measured at various times according to the sample timing (not particular or approximate positions, since initial position, velocity and acceleration are not typically determined), as the read head is scanned relative to the scale. To find the offset for each phase, the minimum and maximum voltages for that phase are found. If a scan over several wavelengths is used, average values are computed. The offset for each phase is equal to the average between the maximum and minimum voltages. The signal amplitudes are equal to the difference between the maximum and minimum voltages, divided by 2. By comparing the amplitude for each phase, the amplitude mismatch is found. The phase mismatch error is found by first removing the amplitude mismatch and offset errors from each phase, and then comparing the relative amplitudes of the two signals at a given point in relation to what they ought to be with no phase relation error.
By utilizing the minimum and maximum voltages of a given phase to perform the calibration method, the method has a number of advantages. One advantage is that the calculation method is straightforward from the data, and does not require any iteration or data adjustment. In addition, less data needs to be saved in a memory because the method only requires the data near the peaks of the output waveform. Furthermore, unlike certain prior art methods which are required to be performed on two signals, the method can be applied to any number of signals from any number of phases. In addition, since only the peak values of the output function are utilized, the method is not so sensitive to unexpected distortions or spatial harmonics of the expected output/position transfer function.
The described method provides a fast calibration method which requires a minimum amount of data, and which can be automatically run in a background mode without inhibiting normal transducer operation. One embodiment where such a method has a particular utility is in inductive transducers. In particular, in many practical inductive transducers, offset and amplitude errors are the dominant errors. Furthermore, inductive transducers are increasingly used in low-power handheld instruments with limited computation speed and memory. Thus, the systems and methods of this invention are extremely well-matched for application to such systems.
Regarding another use of the invention, it should be appreciated that under significant contamination conditions, the signals of most other types of transducers degrade catastrophically, preventing erroneous use. However, inductive transducers are inherently designed to be able to continue functioning in the presence of contaminants. Thus, users may become complacent regarding the contamination of such transducers. In such cases, the self-calibration operations described herein are capable of detecting subtle changes in the operating signals of the inductive transducers, and they therefore provide a basis for alerting the user that contamination, or some other subtle accuracy problem, may be present. Of course, it should be appreciated that the systems and methods of this invention have this same utility in other types of transducers, when the contamination subtly degrades their signals, but is not serious enough to cause the previously described catastrophic signal degradations. Thus, the systems and methods of this invention are particularly important for identifying and correcting subtle operating problems in a wide variety of transducer systems with spatially periodic signals.
Another implementation where the systems and methods of this invention are particularly advantageous is one where increased accuracy is required. For example, it may be desired that a relatively low cost linear scale transducer produce measurements with 0.5 micron accuracy, for which calibration is essential.

System and method for determination of error parameters for performing self-calibration and other functions without an external position reference in a transducer


A lanthanum oxide (La2O3) powder, a germanium oxide (GeO2) powder, and a strontium carbonate (SrCO3) powder are mixed in a ratio so that a composition of the obtained composite oxide LalXm(AO4)6−n(ZO4)nOp satisfies 8≦l+m<10, 0≦m≦2, 0≦n≦2 and 0≦p≦2. Thenafter, the materials are formed and sintered to prepare an oxide ion conductor. The crystalline structure of LalXm(AO4)6−n(ZO4)nOp belongs to the apatite type structure. The conduction of oxide ion occurs when O2− 14 occupying the 2a site of the apatite type structure moves along the c-axis direction.

1. Field of the Invention
The present invention relates to an oxide ion conductor and a method of producing the same. In particular, the present invention relates to an oxide ion conductor which is preferably usable as a solid electrolyte of a fuel cell and which is composed of a composite oxide of lanthanum, a tetravalent element, and an element with which at least any one of them is substituted. The present invention also relates to a method of producing the oxide ion conductor.
2. Description of the Related Art
The solid, in which ions are movable, is widely known as an ion conductor. Also, as well known, the ion has the positive or negative electric charge. Therefore, a current flows through the ion conductor when the ions move.
The mobile ion differs depending on the type of the ion conductor. For example, β-Al2O3, which has a composition of Na2O.11Al2O3, is a good ion conductor for Na+, i.e., a sodium ion conductor, which is adopted as a solid electrolyte of the sodium/sulfur cell. On the other hand, AgI has long been known as a good silver ion conductor from old times.
Recently, because of the growing concern over environmental protection, a fuel cell is used as a low pollution electric power source. Attempts are being made to adopt an oxide ion (O2−) conductor as an electrolyte of the fuel cell. In this case, the entire fuel cell can be made of solid materials, for the oxide ion conductor itself is a solid, making the structure simple. Further, the number of times of maintenance can be reduced because no liquid leakage occurs.
A typical crystalline structure of the oxide ion conductor is the fluorite (CaF2) type structure. Examples of such structure include stabilized ZrO2 doped with about 8 mole % of Y2O3, stabilized ZrO2 doped with about 15 mole % of MgO, Bi2O3 doped with about 25 mole % of Y2O3, and CeO2 doped with about 25 mole % of Gd2O3. In particular, the two types of stabilized ZrO2 described above are practically used as a solid electrolyte of a fuel cell and a partition wall of an oxygen sensor for measuring oxygen concentration in gases or molten metals.
Examples of other oxide ion conductors are those which have the perovskite (CaTiO3) type structure; for example, La0.9Sr0.1Ga0.8Mg0.2O3 and BaTh0.9Gd0.1O3. Usage of these compounds as a partition wall, an oxygen sensor and also a thermistor, is being considered.
The oxide ion conductivity of the oxide ion conductor having the fluorite or the perovskite type structure described above is satisfactory at a high temperature range of about 800 to 1000° C. Therefore, to operate a fuel cell using the oxide ion conductor as a solid electrolyte, it is necessary to raise the temperature of a laminated stack to about 800 to 1000° C. The laminated stack comprises a power generation cell or a plurality of power generation cells electrically connected to one another to constitute the fuel cell. At a temperature lower than the foregoing temperature range, the conductivity of the sold electrolyte (oxide ion conductor) decreases, thus, markedly lowering the power generation efficiency.
When, however, the fuel cell is operated at a high temperature range as described above, a large amount of energy (electric power or the like) is required to heat the power generation cell or the laminated stack. Additionally, inexpensive metal materials, such as stainless steel cannot be used as a member for constituting the fuel cell. The mechanical strength and the corrosion resistance of such a metal material decreases at a high temperature. Therefore, operating the fuel cell at a high temperature significantly increases the running cost.
Both of Japanese Laid-Open Patent Publication Nos. 8-208333 and 11-71169 suggest an oxygen ion conductor composed of a composite oxide of rare earth element(s) and Si, and a method of producing the same. In both of the patent documents, it is described that the composite oxide exhibits excellent oxide ion conductivities at low and middle temperature range of 200 to 600° C., as compared with the two types of the oxide ion conductors described above.
Further, in Solid State Ionics 136–137 (2000 edition), pp. 31–37, studies are made on La10Si6O27, La10Ge6O27 and composite oxides obtained by substituting a part of La with Sr of the two. It is reported that these composite oxides also exhibit excellent oxide ion conductivities in the temperature range of 200 to 600° C. as compared with the two types of the oxide ion conductors described above.
Generally, to produce an oxide ion conductor composed of a composite oxide of a rare earth element and Si, the composite oxide of rare earth elements and Si are sintered at a temperature exceeding 1700° C. This is because the melting point of the foregoing composite oxide is high, and the sintering process is insufficient at a temperature lower than 1700° C. In other words, it is difficult to obtain a sintered product (oxide ion conductor) at a temperature lower than 1700° C., which is strong enough for practical use.
When, however, parts of the reactor, which are used for sintering, such as the heating element, heat insulating material and reaction tube, are heated up to a temperature exceeding 1700° C., the durability rapidly falls. That is, the life of the reactor is drastically shortened and the equipment cost is extremely expensive for producing the oxide ion conductor composed of the composite oxide of rare earth elements and Si. Consequently, the expensive production cost of the oxide ion conductor is a great drawback.
In the scientific paper described above, La10Ge6O27 and La10-XSrXGe6O27, in which a part of La is substituted with Sr, are obtained by isostatically pressing a mixed powder of GeO2, SiO2, and SrCO3 at 275 Mpa, and then sintering in a temperature range of 1600 to 1650° C.
However, large amounts of impurities such as La2GeO5 and La2Ge2O7 are contained in the products of La10Ge6O27 and La10-XSrXGe6O27 obtained from above described procedure. The oxide ion conductivities of the oxide ion conductors containing such impurities are extremely low at low through middle range temperatures as compared with the oxide ion conductivity of the pure oxide ion conductor. The conductivity of the oxide ion cannot be improved, because the impurities in the composite oxides of lanthanum and germanium having the same compositions as described above.


Described is a planar antenna with a process separation device for a fill level radar. The planar antenna including a plate-shaped temperature-resistant process separation device that is arranged between the planar radiator element and the exterior of the antenna.

In fill level measuring technology there are numerous applications in which a high temperature or a high pressure is present. The process temperature may, for example, be up to 400° C. The pressure can have a value of up to 160 bar or more.
To make it possible in these applications to read the fill level with radar sensors, the process connections, in other words the antennae, may have to be constructed such that they withstand this temperature or this pressure without suffering any damage. To this effect, materials such as ceramics, glass or special steel are usually used.
Plastics that are used in known sensors as antenna fillings or seals are above all unable to withstand the high temperatures. These plastics are, for example, polytetrafluoroethylene (PTFE) or polyester ester ketone (PEEK).
If these plastics are to be replaced by ceramics or glass, then due to the high relative permittivities ∈r of the ceramics and of the glass this may not be achieved without further ado especially in the case of higher transmission frequencies of the radar sensor.
On the one hand the dimensions will be very small, and on the other hand the high-frequency behaviour is negatively affected by the large difference between ∈r and the surrounding air.
At frequencies around 6 GHz this may already cause problems and may significantly reduce the sensitivity of a sensor in particular at short range. FIG. 1 shows such a sensor.
A further option of process separation consists of the use of a ceramic plate as a window in a hollow conductor. In this arrangement a plate with a thickness that corresponds to half the wavelength of the transmission frequency (or integral multiples thereof) is inserted as a "window" into the hollow conductor. This is shown in FIG. 2. However, the reflection resulting from the high ∈r of the plate is so high that in this arrangement too the sensitivity at short range can be significantly reduced by multiple reflections.

Patch antenna with a ceramic plate as a cover


A rod is provided with a plurality of bores disposed in a row. In the area of the two end bores the rod has only half the thickness and parallel plane faces. Coaxial to the end bores an annular groove is formed on one face. A toothed rim with radial teeth extends axially on the base of the annular groove. Two such rods may be connected by the teeth of the on tooth rim interdigitating between teeth of the other tooth rim with the rods at a desired angle with each other.

The present invention relates to a construction element for a toy construction set.
Construction elements in the form of connectable blocks, beams, flat rods, etc., are known and commercially available. In such construction elements bores are used to couple two construction elements with each other by inserting connecting parts which lock into the bore. Such a plug-like connecting part is known from Swiss patent CH-PS 658 887, for example.
Furthermore, from the Swiss patent a connecting device is known with a pair of connection parts for detachable, rigid connection of a plurality of longitudinal toy construction elements such as shafts and rods at different angular positions. The connection parts contain a bushing with a cylindrical surface, wherein one front face of the bushing has a toothed edge. Adjacent bushings of this type can be brought into a rigid engagement with each other by nesting the toothed edges, whereby the angular position of the bushings is selectable in accordance with the pitch of the teeth of the toothed edges.
Flat rods are commercially available, in a toy set of the type described, wherein each is provided with an end bore having a toothed edge encompassing one face of a bore so as to provide a rigid connection in a selectable angular position with another construction element which also has a toothed edge, for example, a flat rod or a bushing.
These known and commercially available construction elements have a fundamental disadvantage for toy-construction sets which are based on a defined construction module, (i.e. wherein the dimensions of the elements as well as the positioning of coupling means on the elements are based on a module dimension) since the toothed edges of the corresponding construction elements cannot be randomly formed with respect to their thickness and longitudinal dimensions. As a consequence of this, during assembly of a plurality of such construction elements the module of the construction unit cannot be adhered to in many connection cases as a result of the engagement of their toothed edges. This complicates the construction of certain toy models or renders the same impossible.
It is therefore an object of the invention to provide a construction element of the aforementioned type which is provided with a tooth construction in the area of the bore which permits the element to adhere to a module during random assembly with another adjacent construction element.


A data storage card having optical and magnetic data storage regions, and formed to cooperatively engage both a drive mechanism of a magnetic stripe reader and a drive mechanism of an optical data reader. The card includes a card body defining first and second opposed generally planar surfaces. The card further includes first and second longitudinal edges disposed in spaced opposed relation along the perimeter of the card body. The card further includes first and second lateral edges disposed perpendicular to the first and second longitudinal edges disposed in spaced opposed relation along the perimeter of the card body. The card further includes at least one annular optical data region disposed on at least one of the first and second surfaces. The card further includes at least one magnetic linear data region disposed on at least one of the first and second surfaces. The card further includes an optical carriage engaging aperture formed in the card body to engage a drive mechanism to an optical data reader. Optionally, the card further includes an aperture sheath engageable to the card body and displaceable to extend across the aperture.

The present invention generally relates to the field of portable storage devices for electronic data, and more specifically to card-type devices having both linear magnetic and annular optical data storage regions, such data regions possessing the capability to be written at least once and read several times.
As technological advances have created more powerful and sophisticated electronic equipment at astounding speeds over the years, the size of the software, programs and generated data have grown at proportionally higher rates. Technology that was once 4-bit resolution became 8-bit, which in turn became 16-bit and so forth. As a result, the need for higher capacity data storage has been triggered by such developing technology. For example, at one time, early consumer image scanners were only capable of scanning black and white images, which were typically no more than 300 kilobytes in size (approximately ⅙ the storage capacity of a standard floppy diskette). Today, high resolution consumer color image scanners produce images with millions of colors which are typically as large as 100 megabytes or greater (approximately 50 floppy diskettes). Thus, such advancements in technology demand higher capacity data storage and clearly, such advancements have created a need for a medium capable of supporting such technology.
Ideally, a medium which is portable and easy to carry, highly durable and reliable, generally familiar to the consumer, and has an established base of compatible readers/writers is needed to fill this void. Credit cards have emerged as a standard medium that fits these qualifications. Credit cards are wallet-sized, made of a durable substrate such as plastic, can be embossed with numbers and/or letters, and possess an established market for the use and storage of such cards. Furthermore, consumers are familiar with the way credit cards work and are generally comfortable with using them. Cards in the shape of a credit card are in use by a variety of different companies for the purpose of identifying customers and storing vital information, as demonstrated by the existing use of Automatic Teller Machine (xe2x80x9cATMxe2x80x9d) cards, driver""s licenses membership cards, and other access cards produced for the purposes of identification.
However, credit cards in their current state have a severe limitation which impedes their ability to be used for more sophisticated purposes. Conventional access cards implementing a magnetic stripe have the capability of storing only a minimal amount of data. Generally, this is sufficient for storing and transmitting simple information such as account numbers and other information which does not require a great deal of data storage space. However, the magnetic stripe alone is insufficient to store large amounts of data. Thus, a higher capacity media used in conjunction with the standardized credit card medium may enhance the capabilities of the current credit cards and similar access cards.
Although several different forms of media with high data storage capacities are available, two have emerged as standards: magnetic data regions and optical data regions. Magnetic data storage involves the electrical encoding of analog or digital information on a magnetic surface. Magnetic data stripes found on credit cards are xe2x80x9cswipedxe2x80x9d linearly past the detector/encoder element of the read/write device. Magnetic media, as found in floppy diskettes, hard disk drives, and removable disks, is capable of storing larger amounts of data by spinning the storage material around an axis perpendicular to the plane of the surface of the storage material and aligning annular data xe2x80x9ctracksxe2x80x9d in either concentric parallel nested circular tracks or in a single concentric spiral track.
Optical data regions provide significantly larger storage capacities over magnetic media of comparable size. Two types of optical regions have been developed: those implemented in an annular fashion and those composed of strips or are generally non-annular in form. Annular optical discs are rapidly spun around a stationary assembly where data is then read through a beam of focused light off of concentric or spiral data tracks embedded in the optical disc. Such discs are typically composed of three types of layers which vary in composition depending on the type of optical disc. One layer is composed of a reflective material which allows an optical lens to reflect the beam of focused light off the optical disc and read the binary data back into the optical reader. A second layer contains the data, which is formed by marks or pits in a permanently encoded form found in mass manufactured audio CDs and computer CD-ROMs, or an organic dye polymer such as cyanine, phthalocyanine or azo as used in CD-Recordable discs. Alternatively, CD-Rewriteable discs utilize a polycrystalline layer that alternates between xe2x80x9camorphousxe2x80x9d and xe2x80x9corderedxe2x80x9d states to mimic pits and marks. Both the reflective layer and the data layer are embedded between two layers of a supporting structure, typically comprising a plastic, resin, or polycarbonate substrate.
Non-annular optical data regions and optical strips are typically composed of the similar types of material, yet can be less efficient than annular optical data regions. Existing cards which utilize non-annular optical regions or strips have severely limited data transfer rates due to the excessive amount of time that is typically required to read data from the optical strip. To scan an optical strip, either the card or the scanning beam must continuously move back and forth along successive lines of the data track to read the data. This process requires a specialized apparatus specifically designed to read such optical strips, and also requires very high precision in alignment of the card and scanning beams. It is due to this limitation that a number of inventions utilizing such optical strips necessarily disclose a proprietary apparatus for reading and/or writing to the optical strips.
It is intended in this application that any reference to CD, DVD, and/or LD will include not only the listed formats, but also contemplates other optical formats now known or later developed based upon the same technological concepts. Additionally, any reference to a tray-loading, caddy-loading, cartridge-loading, slot-loading, or hub-loading optical drive device is intended to include existing industry-standard optical drive devices as well as any other loading format now known or later developed based upon the same technological concepts.
Ideally, if an optical disc were to conform to either the 5 inch or 3 inch standard currently in use by CD, DVD, and/or LD device drives, the size and shape of the disc allow it to be compatible with most computer systems, stereo systems and other devices which incorporate industry standard optical drives. When CD players and CD-ROM drives were first developed, music and software publishers contemplated the use of two distinct sizes of optical discs: the 5 inch CD and the 3 inch CD (xe2x80x9cMini-CDxe2x80x9d). Thus, CD, DVD, and LD drive devices with tray-loading carriage mechanisms came to be manufactured with trays that are compatible with both 5 inch and 3 inch optical discs. Such trays have recessed grooves which allow the 3 inch discs to fit snugly into the tray and ensure that the disc is precisely aligned with the optical beam when the tray is closed. Due to the close spacing between data tracks on an annular optical disc, it is necessary that the disc be precisely aligned with the optical beam. Early optical drives were not manufactured with such specialized grooves and in response to this demand, music and software publishers sometimes included an adaptor to convert 3 inch discs into a 5 inch size or sold such adaptors separately. By using such an adaptor, 3 inch discs could be read by any optical drive which reads 5 inch optical discs.
Similarly, caddy-loading optical drives were developed to provide a more stable environment for the optical disc during spin-up and also incorporated the 3 inch recessed grooves. Further, CD and CD-ROM changer systems utilizing a cartridge-loading mechanism were designed to support such 3 inch discs by incorporating the 3 inch recessed grooves into the cartridges. Thus, 3 inch optical discs are fully supported by the industry and are considered to be an established standard in optical disc size.
A credit card shaped data storage card including an embedded linear magnetic stripe, formed to be compatible with existing 3 inch and/or 5 inch optical drive devices, would allow for a higher capacity of data storage, providing a more sophisticated identification system which could read massive amounts of data from the card to verify the identity of the user and effectuate different transactions. Such identification information may be composed of a genetic fingerprint, retinal scan data, voice signatures, photographic images, digital signatures, encryption algorithms and/or countless other types of information which ensure a more accurate form of identification. Additionally, allowing the data to be stored on the access card itself lifts an enormous burden off the system resources of access card readers, which would otherwise be required to store such large amounts of data internally. For example, if a financial institution were to implement a sophisticated identification system that uses retinal and voice scans in conjunction with a conventional magnetic-stripe access card, literally gigabytes or terabytes of information might need to be stored inside the identification system due to the large size of the graphics and sound files. A high capacity data storage card may allow for a cost effective access card reader which has a lower system resource requirement. Such an access card reader capable of reading a high capacity data storage card may then be distributed in areas of the world where an access card reader may otherwise be too expensive to maintain, such as third world countries. Further, a financial institution could store a consumer""s complete account history with a self contained program which executes on the customer""s home or laptop computer.
To implement the promise of such an access card, a way must be found to make them compatible with contemporary computers, ATM machines, magnetic stripe readers, and optical drives to allow everyday use by lay consumers. Contemporary systems using an optical strip generally require the use of a specialized read/write apparatus. Some prior art devices combine both linear magnetic stripes with optical strips while others combine linear magnetic stripes with annular optical regions. Although adding an optical region or optical strip is advantageous due to the increased data capacity, the read/write apparatus may be costly and difficult to integrate into a current marketplace that may be less responsive to integrating a new technology. Existing card readers might need to be updated with a specialized apparatus, causing a higher expenditure for those who wish to integrate the card and a burden on consumers who are unfamiliar with the technology. Additionally, the optical region integrated into contemporary devices is typically configured to be a read-only data region, utilizing pre-recorded data. A read-only data region may provide a secure form of transferring data such that the data written to the card will be unalterable by any means. However, the use of an annular optical data region would provide the benefit of selecting from a variety of materials for the data layer such as an organic dye polymer used in CD-Recordables, polycrystalline used in CD-Rewriteables, or a permanent read-only form. CD-writers are readily available in the marketplace and generally inexpensive. Such CD-writers could potentially be used for the purpose of reading and writing data to annular optical data regions whereas optical strips may not be compatible with conventional CD-writers, and may require a specialized apparatus or manufacturing process to read and write data.
Integrating both a magnetic stripe and an annular optical data region presents the additional problem of providing a card body sufficiently thin enough to pass through a magnetic stripe reader. Conventional credit cards are formed with a thickness of approximately 0.76 mm while conventional annular optical discs may be formed with a thickness of approximately 1.20 mm. Combining both an annular optical data region and a magnetic stripe in a single card requires that the card be engagable with both an optical drive carriage and a magnetic stripe reader depending on the thickness allowed by the magnetic stripe reader. Magnetic stripe xe2x80x9cswipexe2x80x9d type readers may allow a card having a thickness of approximately 0.96 mm. Due to this thickness limitation, a conventional optical disc may be too thick to pass through a magnetic stripe reader. Consequently, a card having both an annular optical data region and a magnetic stripe may be too thick to pass through a magnetic stripe reader if configured with a thickness of 1.20 mm.
A data storage card formed with both an optical annular region and a magnetic data region may also provide a data storage medium for online transactions. Due to the explosive growth of the Internet and online transactions, payments are typically made online via the time consuming process of manually entering customer information and credit card numbers for purchases. Although retailers accept payment via credit cards using magnetic stripe readers, online retailers are continually searching for a way to expedite online transactions by making the payment process as easy as possible. Lay consumers may find a product of interest on the Internet but may be dissuaded from making an online purchase due to the difficulty of inputting account information for fear that such a transaction may require extensive computer knowledge to complete. Thus, several online purchases may be initiated by customers intending to make a purchase but do not ever complete the process, thereby causing the online retailer to lose potential business. In addition, lay consumers may be skeptical of gaining the trust of the Internet and be generally unwilling to input credit card numbers manually into a computer for transmission over the Internet. This fear may be reinforced by the view that hackers are lurking on the Internet waiting to intercept such transactions. Although encryption technology may be as strong as a 128-bit level, encryption technology is continually developing to provide a safer means of transmitting data over potentially unsecure communications lines such as the Internet. A data storage card having an annular optical data region and a magnetic stripe formed to be compatible with a consumer""s computer may further allow a consumer to confidently make online purchases. Such a card may be formed to allow a consumer to insert the card into their personal computer without the wren need to manually input account information. In this respect, a consumer may present the card at a retailer""s magnetic stripe reader for making purchases and may additionally make online purchases from home by inserting the card into a personal computer. Additionally, providing a high data capacity may allow for the card to incorporate a more sophisticated encryption algorithm. Using such security means over the Internet may further alleviate the fears of consumers. Thus, both the difficulty of making an online purchase and a fear of safely transmitting account information may dissuade a potential customer from making an online purchase. It is clear that an ideal data storage card is needed which has the capacity to store large amounts of data, has the ability to accommodate future technologies which may expand the data storage space, is compatible with existing read/write devices, is portable and easy to carry, is highly durable and reliable, is generally familiar to the consumer, provides security features, and most importantly allows seamless and expedient integration into the marketplace.
Contemporary devices have a shape and size roughly the same as a credit card. However, there is generally minimal attention dedicated to compatibility issues which may arise if the card was specifically used in ATM machines or other existing devices. There are tens of thousands of ATM machines in use today and there are several different mechanisms in use which allow the ATM cards to be read. Among the varieties of ATM card mechanisms are those which incorporate a stationary magnetic stripe xe2x80x9cswiper,xe2x80x9d while others require the ATM card to be physically inserted into the drive mechanism/roller drive mechanism. A commonly used ATM tractor drive pulls the card onto a series of rollers arrayed along the center of the card. Current ATM cards are properly adapted to operate in such ATM machines. However, a card having an obstacle, void or physical restraint in the center of the card may become stuck by one of the rollers. This may cause a card to become trapped in and disable feed mechanisms of ATM machines currently in use.
Accordingly, there is a need for a data storage card that incorporates both a magnetic strip and an annular optical region, which is compatible with currently existing optical device drives and magnetic strip readers in widespread use. The present invention addresses the above-described deficiencies of conventional credit cards, providing an access card having high capacity data storage in a credit-card-shaped medium which may be read/written by industry standard optical drives and ATM machines.
In accordance with the present invention, there is provided a data storage card having optical and magnetic data storage regions, and formed to cooperatively engage both a drive mechanism of a magnetic stripe reader and a drive mechanism of an optical data reader. The card includes a card body defining first and second opposed generally planar surfaces. The card further includes first and second longitudinal edges disposed in spaced opposed relation along the perimeter of the card body. The card further includes first and second lateral edges disposed perpendicular to the first and second longitudinal edges disposed in spaced opposed relation along the perimeter of the card body. The card further includes at least one annular optical data region disposed on at least one of the first and second surfaces. The card further includes at least one magnetic linear data region disposed on at least one of the first and second surfaces. The card further includes an optical carriage engaging aperture formed in the card body to engage a drive mechanism to an optical data reader. Optionally, the card further includes an aperture sheath engageable to the card body and displaceable to extend across the aperture.
Preferably, the present invention provides a hybrid portable standardized medium of data storage which is compatible with currently existing data readers and provides a high data storage capacity. A hybrid dual-media data storage card is disclosed comprising a polycarbonate, plastic, resin, or similar material card conforming in size and dimensions generally equivalent to a common credit card. One side of the card may include at least one magnetic stripe and may further implement two or more magnetic stripes, providing two separate swipe zones and enabling the card to be used in standard magnetic card readers such as those found in automated teller machines (xe2x80x9cATMsxe2x80x9d), credit card readers, security entry control devices, and the like. The planar surface opposite to the magnetic stripe side is preferably configured with one or more annular optical data tracks designed to be read by a CD or DVD drive. An optical carriage engaging aperture having rounded corners may allow the card to be inserted into and used in an industry standard CD or DVD drive device comprising those which implement a tray-loading system, slot-loading system, caddy-loading system, hub-loading system, or any other optical drive device which is compatible with 3 inch optical discs.
Additionally, an aperture sheath displaceable to extend across the aperture may be provided. The aperture sheath may be a removable sleeve, the sleeve being operative to substantially cover the aperture portion of the card while exposing the magnetic stripe portion of the card. In this respect, the sleeve supports the roller drive mechanism and prevents the rollers from jamming in the aperture while allowing the magnetic stripe to be read by the magnetic stripe reader. Alternatively, the aperture sheath may be configured as a removable plug, the plug being sized and shaped complementary to the optical carriage engaging aperture. The plug may be inserted by the card user when used with a magnetic stripe reader utilizing a roller drive mechanism and removed when used with an optical drive carriage. Alternatively, the aperture sheath may be configured as a movable member. Preferably, the movable member may be selectable between a first position for exposing the optical carriage engaging aperture to mount the card on the rotatable spindle of the optical drive carriage and a second position substantially covering the aperture to facilitate transport of the card in the roller drive mechanism. In this respect, the user selects the position of the aperture sheath based on the intended application of the card. Further, the aperture sheath may be movable between a first position substantially coplanar with one of the first and second planar surfaces and a second position raised above one of the first and second planar surfaces. By raising the aperture sheath in the second position, the card may be used with optical drive carriages but may not be inserted into magnetic stripe readers such as ATM machines. Inserting a card having an aperture into such an ATM machine may jam the machine when the roller drive mechanism passes over the aperture. Thus, the aperture sheath advantageously safeguards against such possible mistakes by the user. When the user selects the aperture sheath in the first position, the card may then be used with ATM machines since the aperture may be substantially covered and the aperture sheath may be substantially coplanar with one of the surfaces. Such an aperture sheath may be circularly rotated or linearly rotated. Additionally, to further instruct the user, a positional indicator may be provided to indicate whether the aperture sheath is in the first or second position. For example, the position indicator may be a broken arrow which lines up when the aperture sheath is in the position which allows the card to be used with magnetic stripe readers.
The card may be provided with at least one magnetic linear data region for use with magnetic stripe readers. In this respect, one magnetic data stripe allows the card to be used as conventional credit cards. However, a second magnetic data stripe may be provided. A second magnetic data stripe may provide a wholly separate set of data than the first magnetic data stripe. For example, the first stripe may contain an account number and the second stripe may contain a driver""s license number. Or alternatively, the data stripes may contain the same set of data. Due to the card""s potentially thicker profile by utilizing an annular optical data region, the card may require a thinner profile on at least one edge to retain compatibility with magnetic stripe readers. Thus, the card may be provided with two thicknesses. Alternatively, the card may be formed with a single uniform thickness throughout the card body that is sufficiently thin enough to pass through a magnetic stripe reader. In this respect, the card body may have a uniform thickness that is thinner than conventional optical discs.
The card may also be provided with a semiconductor memory chip, providing an additional data storage medium for use with memory chip readers. In this respect, embedding the memory chip may allow the card to be used in magnetic stripe readers, optical drives, and memory chip readers. A smart media card or a flash memory chip may be used as the semiconductor memory chip embedded in the card. Such chips are relatively light and allow for high data capacities. However, memory chips may add additional weight that affects the performance and stability of the card when used with optical drives. To integrate the chip into the card, sufficient space must be provided. Thus, the optical carriage engaging aperture may be offset from the center to create the necessary space. By offsetting the optical carriage engaging aperture, the card may then become unbalanced when rotated in an optical drive carriage. Or, the card may become offset from the additional weight of the semiconductor memory chip. To balance the card and reduce the weight of the card, a plurality of recesses may be formed on one of the planar surfaces. Such recesses may be formed sufficient to offset the weight of the semiconductor memory chip or the recesses may be formed according the necessary reduction in weight for balancing the card in an optical drive carriage.
The present invention may additionally incorporate a dual-purpose optical carriage engaging member which is raised above one of the planar surfaces and may be disposed about the outermost perimeter of the optical data region. As an optical carriage engaging member, the raised portion may be sized and shaped complementary to the recessed grooves of an optical drive carriage. At the same time, the member may also serve as an optical surface protecting ridge. When the card is used with magnetic stripe readers, the optical data region may become damaged or scratched from the internal roller drive mechanisms or from constant use. Over time, such scratches may affect data integrity and reduce the life of the card. Thus, the optical surface protecting ridge may be provided for minimizing such damage by allowing the friction caused by the magnetic stripe readers to be placed upon the ridge and not the optical data region.
Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.

Data storage card having both linear and annular data regions


An image capturing apparatus that is capable of loading a plurality of memory media that includes a plurality of medium wearable units where a respective memory medium is loaded detachably; a medium selector for selecting from said plurality of medium wearable units a write-execution medium wearable unit that should execute writing of data; and a selection controller for controlling said medium selector, said selection controller having an automatic selection controller for selecting said write-execution medium wearable unit according to a predetermined automatic selection basis that reflects a user's medium selection trait.

1. Field of the Invention
The present invention relates to a digital camera. In particular, the present invention relates to a digital camera that is capable of loading a plurality of memory media.
2. Description of the Related Art
Digital cameras are popular as a form of convenient electronics. One of the features of digital cameras is that digital cameras are capable of recording photographed images in a memory device. The memory device can be detached from the body of a camera, be set to a personal computer, or be brought to a photo shop. A typical memory device and its medium wearable unit are a memory card and a card slot.
It has been proposed that a digital camera be equipped with a plurality of card slots so that a plurality of memory cards described above can be loaded simultaneously. If a digital camera is equipped with a plurality of card slots, photographed images can be recorded in the plurality of memory cards, thereby the number of photographable images will be increased. However, a user has to designate in which memory card of a card slot to record data. If the designated card slot does not have a memory card loaded, the user has to conduct the necessary operations, such as to reselect a card slot, because the data will not be recorded as it is. Thus, simply increasing the number of card slots makes the operation complex.
In the Japanese Patent Application Laid-Open No.H5-91455, a digital camera is equipped with two memory cards. A memory card for recording is switched to another according to the available memory of these memory cards. This automatic switching partly reduces the complexity of the user operations. However, it is generally after there in not enough available memory that a user considers the available memory when manually selecting a card slot. In the ordinary state when the available memory is enough, users usually consider whether the recorded data is easy to manage rather than to consider whether there is enough available memory. If the card slot is switched to another according to the available memory for its problems above, data may be recorded in the unintended memory card, thereby the later data management may become inconvenient. This inconvenience may impair the use of the digital camera after all. The above problem is not limited only to memory cards and card slots. Similar problems may arise regarding a given memory medium and its medium wearable unit.

Apparatus and method to capture image and other data and recording onto multiple recording medium


A method for measuring and determining a rotation angle of a rotating object in which a clock track corresponding to a desired angular resolution is applied on a magnetic, optical or optomagnetic storage medium. The storage medium is then rotated synchronously with the rotating object, and during the operation a pulse sequence corresponding to the clock track is read from said storage medium. The read pulse sequence is then supplied for further processing to following electronics in which the actual rotation angle is firstly stored in a FIFO memory and secondly directly available for further uses. Furthermore, the invention provides an apparatus for measuring and determining a path difference in Michelson interferometers in which path difference are generated via a rotary movement, for example of a rotating retroreflector. A memory medium is rigidly connected to the rotation shaft of the rotating retroreflector generating a path difference and on said medium a clock track corresponding to the sampling theorem is applied and during the rotation movement is read by a read head fixedly associated with the storage medium. During operation said pulse sequence is read by the read head and supplied to following signal electronics in which from the pulse sequence the desired clock pulse and thus the path information is then obtained.

1. Field of the Invention
The invention relates to a method for measuring and determining a rotation angle of a rotating object in which on a magnetic, optical or optomagnetic storage medium a clock track corresponding to the desired angular resolution is applied, the storage medium is rotated synchronously with the rotating object, in operation a pulse sequence corresponding to the clock track is supplied for further processing to following signal electronics in which the actual rotation angle or the actual angular velocity of the rotating object is available.
2. The Prior Art
As sensors for rotary movements and in conjunction with mechanical measuring means, such as measuring racks or threaded spindles, for linear movements rotation pickups and angle measuring devices are used. Such devices are employed in automation in general mechanical engineering, in robots and handling apparatuses, adjustment and displacement means as well as devices for information technology, antennas, direction devices and also testing and measuring devices of all kinds.
In incremental measurement the output signals of incremental rotation pickups and angle measuring devices are supplied to counting electronics in which the measured value is determined by counting individual "increments". In an incremental rotation pickup the shaft is mounted in a flange with ball bearings set free of play and carries a grating disc of glass on which a radial grating ruling is applied. The opaque lines, which are about twice as wide as the transparent gaps therebetween, consist of chromium which has been evaporated in vacuum to the glass body by the DIADUR method. At a slight distance from the ruling, on the flange a scanning plate is arranged which on small fields carries in each case the same grating ruling or division as the grating disc. However, on the four fields of the scanning plate the lines are arranged respectively , offset by a quarter of a division period. In addition, on the grating disc, as on the scanning disc, a field is applied having a reference mark which with coarser divisions is formed by a single line and with fine divisions by a line group.
All these fields are permeated by a parallel light beam which is generated by a light source and a lens. The light flux is modulated on rotation of the grating disc and impinges on photocells which generate two electrical approximately sinusoidal signals and a reference mark signal. The two sinusoidal signals are electrically 90.degree. out of phase with respect to each other; a signal period of 360.degree. corresponds to a rotation angle through one division period of the radial grating ruling.
With incremental rotation pickups made up in this manner the production is complicated and in addition high angular resolutions and non-linear angle encoding are very difficult to implement; for this reason incremental rotation pickups made in this manner are expensive.
In Michelson interferometers in which rotating retroreflectors are used to generate the path differences, the distance measurement is carried out by means of a laser radiation. The laser radiation passes through the interferometer and from the resultant interference signal, since the wavelength of the laser radiation is known, the path difference can be calculated. A disadvantage in this type of distance or path measurement is that either a reference interferometer for the laser radiation must be coupled to the signal interferometer or the laser radiation must be conducted through the signal interferometer. In the second case a separate region of the beam splitter must be suitable for the laser radiation. As a result, either the region of the signal radiation is restricted or beam splitters, mirrors, lenses and the like larger components must be employed. Furthermore, it is complicated to make a beam splitter which has different optical properties in two geometrically separate regions because the signal radiation usually lies in the infrared whilst the laser is usually an HeNe laser with a wavelength of 632.8 nm. It is further disadvantageous that economical laser tubes as a rule have a low life whilst long-life tubes are expensive.

Method for measuring and determining a rotation angle of a rotating object

Deutsche Forschungsanstalt fur Luft- und Raumfahrt


First, a field oxide region, a pad oxide layer and a first nitride layer are formed on a silicon substrate, respectively. Then, a portion of the first nitride layer is removed. A first oxide layer and a nitride spacer are formed on the substrate, respectively. Portions of the first oxide layer and the pad oxide layer are removed to form a first region of the first oxide layer and a second region of the first oxide layer. Then, an ion implantation is performed to form a punch-through stopping region. Next, a second oxide layer and an amorphous-Si layer are formed on the substrate, respectively.. Portions of the a-Si layer are etched back. Next, the first nitride layer and the nitride spacer are removed. An ion implantation is performed to form a source, a drain and a doped region at the bottom of the second region of the first oxide layer. Then, a Rapid Thermal Process is used to drive dopant diffusion to form an extended source/drain junction. A third oxide layer is deposited on the substrate, wherein an air-gap is formed between the first region of the first oxide layer and a-Si layer. Finally, portions of the third oxide layer and the pad oxide layer are etched back to form an oxide spacer with the air-gap.

From the birth of the first integrated circuits at 1960, the number of device on a chip has grown in an explosive increasing rate. In recent year, the progress of semiconductor technology has driven the integrated circuits technologies toward Ultra Large Scale Integration (ULSI) level or even higher level. In ULSI, some negative effects result from the higher integration of devices and the smaller scale of devices. Metal Oxide Semiconductor Field Effect Transistor (MOSFET) device is the most important and widely applied devices in the integrated circuits technologies.
To satisfy the requirement for high speed circuit operation and high density of ULSI level, the ultra-short channel Metal Oxide Semiconductor (MOS) device was proposed. One of some articles relates to the ultra-short channel MOS device. Please see "Performance and Reliability Optimization of Ultra Short Channel CMOS Device for Giga-bit DRAM Applications, 1995, IEEE, IEDM 95-435". However, it is difficult to define the gate length to be below 0.1 .mu.m due to the limitation of current optical lithography. One of some articles relates to the above problems. Please see "SUB-50 NM GATE LENGTH N-MOSFETS WITH 10 NM PHOSPHORUS SOURCE AND DRAIN JUNCTIONS, 1993, IEEE, IEDM 93-119".
For realizing high speed and low power ULSI devices, the conventional Complementary Metal Oxide Semiconductor (CMOS) device has been designed with thin gate oxide and short channel length. But the technology of fabricating CMOS devices will increase the gate to drain capacitance. Because the parasitic capacitance is consisted of the gate capacitance, the gate to drain capacitance, the junction capacitance and the gate fringing capacitance, the increasing gate to drain capacitance will augment the parasitic capacitance. So, minimizing the gate to drain capacitance is another key issue for realizing high speed and low power ULSI devices. One of some articles relates to the above problems. Please see "Impact of Reduction of the Gate to Drain Capacitance on Low Voltage Operated CMOS Devices, 1995 Symposium on VLSI Technology Digest of Technical Papers". The above article proposes a new Transistor-gate (T-gate) CMOS device with dual gate structure using amorphous-Si/Polysilicon layer in order to reduce the gate to drain capacitance without the transconductance degradation.
The gate fringing field capacitance (CFR) becomes more important as the gate length is reduced to deep sub-.mu.m. One of some articles relates to the above problems. Please see "A Gate-side Air-gap Structure (GAS) to Reduce the Parasitic Capacitance in MOSFETs , 1996 Symposium on VLSI Technology Digest of Technical Papers".
So, solving above problems is required.

Method to form ultra-short channel MOSFET with a gate-side airgap structure


A lighting control system for maintaining a predetermined light level in a lighting zone illuminated by both natural and artificial light includes a CPU connected to an electrical power source and to an electric light. The CPU directs a predetermined initial amount of current to the electric light when the electric light is activated. The system includes a sensor for sensing the light level within the lighting zone and communicating the sensed level to the CPU. Following a comparison of the sensed light level with a predetermined light level, the CPU either increases or decreases the amount of current to the electric light for maintaining the predetermined light level. A thyristor connected to the CPU blocks and releases current flowing to the electric light for gradual power changes. Present light level sensing and current adjustments continue while the electric light is activated.

This invention relates generally to lighting apparatuses and, more particularly, to a lighting system and method for maintaining a predetermined light level within a lighting zone that is illuminated by a combination of natural and electric light sources.
Maximizing the life of electric light bulbs, whether fluorescent or incandescent, is economically desirable. The failure of light bulbs may be due to the natural burning out of a bulb filament or failure of related hardware. Light bulbs are also subject to failure as a result of repeated energizing of the bulb to full voltage. Therefore, limiting the number of times a bulb is immediately energized to full power may increase bulb longevity as will energizing bulbs to the degree necessary to maintain a desired level of light.
Various devices and circuits have been proposed in the art for gradually energizing a light bulb so as to decrease the risk of immediate filament overload or to increase the longevity of a bulb. Although assumably effective for their intended purposes, the existing devices do not increase the bulb life by providing gradual current adjustments to a bulb while automatically adjusting current so as to maintain a predetermined light level within a room illuminated by both natural and artificial light sources.
Therefore, it is desirable to have a lighting control system that maximizes bulb life by automatically increasing or decreasing the amount of current flowing from an electrical power source to an electric light source so as to maintain a constant predetermined light level within a lighting zone. Further, it is desirable to have a lighting control system that gradually supplies electrical current to the electrical light source to maximize bulb life.
A lighting control system and method according to the present invention includes a control unit having a central processing unit (CPU) positioned therein. The control unit may be positioned in a room or other lighting zone that is illuminated by both natural sunlight and artificial light such as electric lamps. The CPU is electrically connected to an electrical power source such as an AC electrical power outlet. The CPU is also electrically connected to the electric lights, either directly or to the AC outlets into which the lights are plugged. The control unit further includes a light sensor for sensing the total amount of light within the respective room or lighting zone. The total amount of light may be quantitatively measured in lumens. The sensor is connected to the CPU and adapted to deliver sensed light level readings thereto.
The CPU includes a memory element capable of storing a predetermined light level. This level may be a default level or may be selected or input by a user. The CPU is also programmed to allow a predetermined amount of current from the electrical power source to flow to the electric light sources when those light sources are activated. Thereafter, the CPU compares a sensed light level reading with the predetermined light level and determines if the amount of current flowing to the light sources needs to be increased or decreased. If the sensed light level is less than the predetermined light level, then the CPU allows an increased amount of current to flow to the electric light sources. Similarly, the CPU allows less current to flow if the sensed light level is greater than the predetermined light level. Therefore, the total amount of light in the lighting zone is generally maintained at the predetermined level. For example, less artificial light is provided if the natural sunlight directed into the lighting zone increases and vice versa. This saves electricity and increases the longevity of the light bulbs, especially during peak periods of sunshine.
The control unit further includes a thyristor electrically connected to the CPU. As current flows from the electric power source toward the electric light sources, the thyristor cyclically blocks and releases the electricity at a predetermined rate such that the current is gradually received by the lights. Under CPU control, the predetermined rate changes such that the complete amount of current ultimately is being delivered to the electric lights. This gradual current adjustment also promotes longevity of the light bulbs.
Therefore, a general object of this invention is to provide a lighting control system which causes the illumination of electric lights within a lighting zone to gradually increase or decrease as the amount of natural light therein proportionately decreases or increases.
Another object of this invention is to provide a lighting control system, as aforesaid, that maintains a predetermined level of light in a room that is partially illuminated by natural light and partially illuminated by electric light sources.
Still another object of this invention is to provide a lighting control system, as aforesaid, which controls the rate at which electric lights are energized or de-energized.
Yet another object of this invention is to provide a lighting control system, as aforesaid, having a light sensor for sensing the level of light within a lighting zone.
A further object of this invention is to provide a lighting control system, as aforesaid, in which a desired level of light to be maintained within a lighting zone may be selected by a user.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.


A transmission format cache may be implemented at a database storage node. Versions of data items stored in a database at the database storage node may be processed according to anticipated access requests to generate an anticipated access responses. The anticipated access responses are then stored in a transmission format cache to provide low latency reads of the data items. The versions of the data items may be processed as a result of updates to the database items. The database storage node may be one of a plurality of database storage nodes implementing a distributed database system with the transmission format cache implementing a portion of a distributed response cache providing low latency, eventually consistent or consistent reads of data items in a distributed database.

Database systems may organize database storage in various ways in order to optimize varying workloads. As a result, particular data items stored in the database in a format for optimization may have to be reformatted by the database system in order to return the data items to clients of the database. For example, some databases may be organized such that certain attributes of data items are grouped together so that various attributes of a data item may be collected from different areas of storage in order to return the data item on request.
While embodiments are described herein by way of example for several embodiments and illustrative drawings, those skilled in the art will recognize that the embodiments are not limited to the embodiments or drawings described. It should be understood, that the drawings and detailed description thereto are not intended to limit embodiments to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include", "including", and "includes" mean including, but not limited to.
Various units, circuits, or other components may be described as "configured to" perform a task or tasks. In such contexts, "configured to" is a broad recitation of structure generally meaning "having circuitry that" performs the task or tasks during operation. As such, the unit/circuit/component can be configured to perform the task even when the unit/circuit/component is not currently on. In general, the circuitry that forms the structure corresponding to "configured to" may include hardware circuits. Similarly, various units/circuits/components may be described as performing a task or tasks, for convenience in the description. Such descriptions should be interpreted as including the phrase "configured to." Reciting a unit/circuit/component that is configured to perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112(f) interpretation for that unit/circuit/component.
This specification includes references to "one embodiment" or "an embodiment." The appearances of the phrases "in one embodiment" or "in an embodiment" do not necessarily refer to the same embodiment, although embodiments that include any combination of the features are generally contemplated, unless expressly disclaimed herein. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.
Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.
A reference herein to a patent document or any other matter identified as prior art, is not to be taken as an admission that the document or other matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

Transmission format cache for database reads


An optical beam scanning device includes a rotating polygon mirror for scanning a beam from a pre-deflection optical system in a main scanning direction and two mirrors 23, 25 for imaging the beam scanned by the rotating polygon mirror 5 on an image plane. The device is arranged so that a first mirror 23 at the rotating polygon mirror side 5 has a negative power in the main scanning direction and a second mirror 25 at the image plane side has a positive power in the main scanning direction. Thereby, the degrees of freedom of shape and arrangement of process unit or the like can be made higher and an apparatus can be downsized by securing the distance between the last imaging element and the image plane while suppressing the increase in the optical path length between the reflection surface 5A of the rotating polygon mirror 5 and the image plane.

The present invention relates to an optical beam scanning device including two mirrors for imaging a beam scanned by a rotating polygon mirror on an image plane.
In a scanning optical system using lenses for a post-deflection optical system of an exposure apparatus, there are design restrictions as achromatization for preventing displacement of beam position and imaging position according to variations in wavelength. This is because refractive indexes of lens materials become different according to the difference in wavelength. Contrary, a mirror has an advantage that it has less wavelength dependence, and inventions using mirrors for the scanning optical system have been made. As an example, there is a laser scanning device described in Japanese Patent Application Laid-Open (JP-A) No. 2001-56445.
In this laser scanning device, two mirrors are used in a post-deflection optical system as shown in FIGS. 1 and 2, and powers of the two mirrors in the main scanning direction are positive and positive, respectively.
Accordingly, a principal point by the two mirrors is located between the first mirror and the second mirror, and the distance from the last imaging element to the image plane can not be taken larger than the f value of an fθ mirror.
Further, JP-A Nos. 2001-13441 and 2001-13442 discloses a device using one mirror, and, in this case, a principal point is located on the mirror surface. Accordingly, the distance from the last mirror surface to the image plane becomes nearly equal to the value of the f value of the fθ mirror.
Further, there is a device using a pair of plastic lenses as one employing optical elements using inexpensive molded components, and there is a restriction that large powers can not be provided to the lenses themselves in order to suppress the influences of temperature and humidity to the refractive indexes and shapes. On this account, it has been necessary to make an effective field angle smaller and raise image frequencies in order to secure the distance between the last imaging element and the image plane. If aluminum evaporation is performed on the molded component for use as a mirror, the influences of temperature and humidity to the refractive indexes can be removed. In the past, there has been a device in which the first mirror is formed in a concave shape having a positive power, however, the image side principal point becomes nearer the rotating polygon mirror side than the second mirror, and the distance between the last imaging element and the image plane becomes shorter.
In order not to be affected by irregularities in faces of the rotating polygon mirror (amounts of variation in the case where the distance from the rotational center to the reflection surface differ from face to face), it is considered that a beam nearly paralleled to the main scanning direction enters the rotating polygon mirror (see FIG. 1). In this case, the f value of fθ characteristic becomes nearly equal to the combined focal length in the imaging system. Accordingly, the location at the combined focal length from the image plane side principal point becomes an image plane.
As one method for securing the distance between the last imaging element and the image plane, there is a method of making the f value larger. However, this makes the θ value smaller when scanning the same width. In this case, there are following two drawbacks.    (1) When the θ value becomes smaller, the image frequency as a frequency of laser ON/OFF corresponding to one pixel is raised.
The beam position is designed so that the relationship h=fθ is satisfied. Assuming that the size of one pixel is Δh and the deflection angle when one pixel is formed is Δθ, Δh=fΔθ holds. The equation is expressed by Δh=fωΔT where the deflection angular velocity of the beam is ω and the time for forming one pixel is ΔT. Accordingly, the image frequency is expressed by 1/ΔT=fω/Δh. This shows that the image frequency is proportional to f, and, as f is made larger, the image frequency is also raised.    (2) Since, as the smaller the θ value, the distance from the reflection surface of the rotating polygon mirror to the last surface of the imaging element also becomes larger in proportion to f, the entire optical path length becomes longer and the unit becomes upsized.
As another method, there is a method of making the image side principal point in the main scanning direction nearer the image plane side than the last imaging element.
The case where two optical elements having powers φ1 and φ2 are located at distance d2 is considered using paraxial ray theory.
The combined power isφt=φ1+φ2−d2×φ1×φ2  (1)
The object point side principal point position is expressed from the first optical element by:Δ1=d2(φ2/φt)  (2)
The image plane side principal point position is expressed from the second optical element by:Δ2=−d2(φ1/φt)  (3)where Δ1 and Δ2 are positive at the image plane side.
Here, in the main scanning direction, it is necessary to set the combined power φ1 positive so that a nearly parallel beam enters the optical element and is imaged on the image plane.
To make the image plane side principal point position nearer the image plane side than the second optical element, the power allocation may be made so that Δ2>0 holds.
Since the distance between elements is positive, d2>0 holds. As described above, since the combined power is positive, φt>0 holds. From the above conditions and (Eq3), if φ1<0, Δ2>0 can be realized.
Furthermore, to make the combined power positive, the following condition is required. First, rewrite (Eq1) and the condition is expressed by:φt=φ1+φ2(1−d2×φ1)Since d2>0 and φ1<0, and (1−d2×φ1)>0 and φ1<0, it is necessary that at least φ2>0 so that φt>0 holds. To be precise, it is necessary that φ2>−[φ1/(1−d2×φ1)] holds.
Therefore, in an optical system including a pair of optical elements, when the optical element at the object point side is formed by an optical element having a negative power and the optical element at the image plane side is formed by an optical element having a positive power, the image side principal point can be made nearer the image plane side than the image plane side optical element (see FIG. 3).
For the purpose of achromatization of axial aberration, the configuration with a pair of lenses in which the power of the lens at the deflector side is made negative and the material of the lens at the deflector side is made to have high refractive index and high dispersion property has been developed. The purpose is in achromatization as a problem specific to lenses. On the other hand, there is no change in power due to wavelength in a mirror and there is no problem of achromatization specific to lenses. Accordingly, for mirrors, examination on power allocation as above lenses has not been made.

Optical beam scanning device having two sets of fθ mirrors where the mirror base and mirror face have differing coefficients of linear expansion


A host computer transmits a user ID and a list of vending machine IDs to a portable communication terminal. When the user selects from the list a vending machine through which the user makes a payment, the user ID and the ID of the selected vending machine are transmitted from a portable communication terminal to the host computer. The host computer issues to the vending machine corresponding to the vending machine ID an instruction to enter a payment acceptable mode. When the user makes a payment at the vending machine, the amount of the payment is transmitted to the host computer.

The present invention relates to a system for handling real money in electronic commerce.
Recently, the electronic commerce through a network such as the Internet, etc. has become more and more popular in conducting transactions of merchandise and services. In the electronic commerce, a payment method is very important. For example, assume that merchandise is to be sold on a Web page of the Internet. In this case, as a payment method, a buyer can notify a seller of his or her credit card number. However, in this method, even an encrypted credit card number can be tapped. Another method is to make a payment in a bank, etc. before and after a buyer buys merchandise, etc. However, in this method, it is necessary to make a payment each time a buyer buys merchandise. Since a buyer has to perform a burdensome payment process, this method is not convenient.
In the above situation, there has been suggested method of conducting a transaction using electronic money, which can be processed through a network. In this method, a payment can be made by transferring the electronic money between a buyer and a seller. Thus, it is not necessary to use any real money in each transaction. However, it is necessary to buy electronic money using real money before conducting a transaction. Therefore, the above mentioned problem cannot be completely solved.
An example of the method will be described below. For example, a user first buys at a real shop a card which can pay a predetermined amount. When the user buys merchandise, etc. through a network, the user can make a payment for the merchandise by notifying the seller of his or her identification number described on the card. After buying the merchandise, the amount equivalent to the merchandise, etc. is subtracted from the total amount of money which can be paid by using the identification number. Thus, in this method, the identification number practically functions as electronic money or an electronic wallet. The card is a media for assigning the identification number to the user. Thus, although the identification number is tapped, the damages of the user can be limited to the predetermined amount. However, this method is not convenient because the user has to buy a card at a shop in advance.

Cash payment system using vending machine


A detector and a method for determining the presence of a fluid are disclosed. The detector comprises a probe having a thermistor with the probe being arranged to be exposed to a fluid and to allow thermal flow between the thermistor and the fluid, a temperature sensor for measuring the temperature of the thermistor and a controller. The controller is arranged to supply electrical power to the thermistor when it is below a predetermined temperature to heat it up and to turn off the supply of electrical power to the thermistor when it is at or above the predetermined temperature. The presence or identity of a fluid exposed to the probe is determined based on the proportion of time that power is supplied to the thermistor to maintain it substantially at the predetermined temperature. The ambient temperature of the fluid to which the probe is exposed may also be measured and electrical power may be supplied to the thermistor to keep it substantially at a predetermined temperature above the measured ambient temperature.

This invention relates to detection of the presence of media, in particular fluids.
The detection of the presence of fluids has many applications. For example, domestic heating systems preferably have a sensor to detect whether or not liquid is present in the heat exchanger and whether or not it is flowing in order to confirm that the pump is running. Detectors are also employed in many other applications, such as engine coolant systems for vehicles and domestic appliances such as refrigerators, washing machines etc.
A fluid sensor may comprise a probe including one or more thermistors. The thermistors are preheated by applying a voltage from a heating circuit. When the probe is exposed to fluid, the fluid conducts heat away from the thermistor reducing its temperature. As the effective thermal conductivity of fluids such as air, oil, water and moving fluids such as moving water are different, the presence of each of these at the surface of the probe can be determined remotely by measuring the reduction in temperature of the thermistor. Such a flow sensor is disclosed in EP-A-1 647 813.
A thermistor may also be kept at a substantially constant predetermined target temperature. The constant predetermined target temperature may be at a set level above the surrounding ambient temperature, such as by 20 to 30° C. By measuring the power needed to keep the thermistor at the constant temperature, a rate of power dissipation into the surrounding media can be determined, and thus the presence/absence or nature of the fluid in which the thermistor is provided may be determined.
Electrical power is generally applied to a thermistor by a constant current source. When the thermistor is at the required predetermined temperature, a suitable resistance load is introduced into the circuit supplying electrical power to the thermistor so that the proportion of electrical power and thus heating of the thermistor is reduced to prevent it from heating up further, beyond the predetermined target temperature. However, the introduction of a resistance load wastes a considerable amount of power, especially if the detector is used for long periods of time or constantly.
It would be desirable to be able to reduce power consumption in a fluid detector.