An optical information reproduction apparatus has a section which scans with an optical beam an optical information recording medium in which information is recorded. The optical beam is modulated according to the information. From this modulated optical beam, the corresponding reproduction signal is generated, then binary-converted. A sampling clock synchronized with this binary-converted reproduction signal is generated. The binary-converted reproduction signal is sampled with the synchronized sampling clock to reproduce the information. The response of the sampling-clock generating section can be switched. This optical information reproduction apparatus enables reliable information reproduction.

1. Field of the Invention
The present invention relates to optical information reproduction apparatuses for reproducing digital information recorded in an optical information recording medium, and more particularly, to an optical information reproduction apparatus for reproducing digital information by sampling a binary-converted reproduction signal with a clock signal.
2. Description of the Related Art
There are known many optical information recording media in which information is recorded with an optical beam or from which recorded information is read with an optical beam. Some of them can be recorded and reproduced, and some are reproduced only. They have various shapes, such as those of disks, cards, and tape. Among these optical information recording media, it is considered that applications for optical cards will extend due to their features of easy production, superior portability, and accessibility. Various optical information recording and reproducing apparatuses have been proposed for optical cards.
In such an optical information recording and reproducing apparatus, recording and reproduction are performed with continuous control of automatic tracking and automatic focusing. To record information on a recording medium in the apparatus, an optical beam converged to a minute spot is modulated according to the information to be recorded and an information track is scanned with the modulated optical beam. With the beam irradiation as described above, a piece of information is recorded on an information track as an information pit row which can be detected optically. To reproduce information recorded on a recording medium, an information pit row on an information track is scanned with an optical beam having a constant power which does not cause recording on the medium, and the light reflected from or passing through the medium is detected.
FIG. 1 is a block diagram illustrating an outlined configuration of a typical optical information recording and reproducing apparatus which employs the information recording and reproducing method described above.
In FIG. 1, the optical information recording and reproducing apparatus comprises a semiconductor laser 101; a collimator lens 102, a diffraction grating 103, a polarized-beam splitter 104, a quarter-wavelength plate 105, and an objective lens 106 placed in that order in the direction in which the light flux emitted from the semiconductor laser 101 advances; and a toric lens 108 and an optical detector 109 placed in that order in the direction in which the light flux separated by the polarized-beam splitter 104 advances. An optical card 107 is placed at the focus of the objective lens 106.
In the above-described optical information recording and reproducing apparatus, the light flux (S polarized light) emitted from the semiconductor laser 101 is made parallel by the collimator lens 102, and then divided into a plurality of light flux by the diffraction grating 103. The divided light flux is converged on the optical card 107 through the polarized-beam splitter 104, the quarter-wavelength plate 105, and the objective lens 106.
The light reflected from the optical card 107 passes through the objective lens 106 and the quarter-wavelength plate 105, and is made to P polarized light. The light is reflected by the polarized-beam splitter 104, and enters the optical detector 109 through the toric lens 108.
Among light flux divided by the diffraction grating 103, the 0th-order diffraction light ray is used to record and reproduce information and to perform automatic focusing control (hereinafter called AF). Automatic tracking control (hereinafter called AT) is performed with the positive and negative first-order diffraction light rays. The astigmatism method is employed for AF and the three-beam method is used for AT.
FIG. 2A and FIG. 2B illustrate a recording surface of an optical card and the relationship between the recording surface and the scanning speed of an optical spot scanning on the optical card. FIG. 2A is an outlined plan of the optical card. FIG. 2B shows a condition that the scanning speed is not constant at both edges of the optical card.
As shown in FIG. 2A, many information recording and reproducing tracks are arranged in parallel on the optical card 107. Part of the tracks, T1, T2, and T3, are illustrated on the figure. These tracks T1, T2, and T3 are partitioned by tracking tracks tt1 to tt4. The tracking tracks tt1 to tt4 are grooves, or formed with a material having a different reflectance from that of the tracks T1 to T3. The tracking tracks are used as guides for getting a tracking signal.
FIG. 2A shows an example in which information is recorded in or reproduced from the track T3. The 0th-order light ray 110 for recording, reproduction, and AF is emitted to the track T3, and the positive and negative first-order light rays 111 and 112 are emitted to the tracking track tt3 and tt4, respectively. From the reflection light of the positive and negative first-order light rays 111 and 112, a tracking signal, described later, is obtained in order to control the 0th-order diffraction light ray 110 such that it scans exactly on the track T3. The diffraction light rays 110, 111, and 112 scan on the optical card 107 right and left on the figure with a not-shown mechanism with the same positional relationship being maintained.
There are two scanning methods, in which an optical system or an optical card is moved. In either method, since the optical system and optical card reciprocate each other, the scanning speed is not constant at both edges of the optical card. FIG. 2B shows this condition. The horizontal axis shown in FIG. 2B indicates the right and left direction of the optical card and the vertical axis indicates the scanning speed. Usually, the constant-speed scan area, located at the center of the optical card 107, is used for a record area.
The format of an information recording and reproducing track of the optical card 107 will be described next.
FIG. 3A is an example illustrating the format of an information recording and reproducing track of an optical card. On an information recording and reproducing track TN, n data blocks (sectors) are recorded or pre-formatted. FIG. 3B is a view illustrating an example of the format of a data block shown in FIG. 3A.
In FIG. 3A and FIG. 3B, a forward phase-locked-loop synchronizing signal 200 is a continuous repeated data pattern recorded at the top of a data block. By synchronizing this forward PLL synchronizing signal 200 with a sampling clock generated by the PLL control signal generator, data preceded by the forward PLL synchronizing signal 200 is surely reproduced.
A data-read-start-position synchronizing signal 201 recorded between the forward PLL synchronizing signal 200 and a data section D1 indicates the position where data-section read starts. This data-read-start-position synchronizing signal 201 uses a special pattern which is not used in data sections. The data-read-start-position synchronizing signal 201 is recognized as a data-read-end-position synchronizing signal when data is reproduced backward. In data sections D1 to Dm, user data, an error correcting code (ECC), which is a redundant word for detecting and correcting errors, and other items are recorded.
An inter-data synchronizing signal 202 prevents data errors from spreading substantially if the sampling clock is out of synchronization due to dust or scratches in data sections. A special code pattern similar to that used for the data-read-start-position synchronizing signal 201 is used for the inter-data synchronizing signal 202.
A data-read-end-position synchronizing signal 203 is recorded immediately after the last data section in one data block. A special code pattern similar to that used for the data-read-start-position synchronizing signal 201 is used for the data-read-end-position synchronizing signal 203. This data-read-end-position synchronizing signal 203 is recognized as the data-read-start-position signal when the optical beam scans backward.
A backward PLL synchronizing signal 204 is a continuous repeated-data pattern used for synchronizing with a sampling clock generated by the PLL control signal generator, described later, when information is reproduced backward.
Reproduction of information on an information recording and reproducing track of the optical card 107 configured as described above will be described next.
FIG. 4 is an enlarged view of the track to which the diffraction light rays 110, 111, and 112 are emitted as shown in FIG. 2A.
In FIG. 4, the 0th-order diffraction light ray 110 for recording, reproduction, and AF is located at the center between the positive and negative first-order diffraction light rays 111 and 112 for AT, and moves along the center line of the track T3. Hatched sections 113a, 113b, and 113c indicate positions where data is recorded with the 0th-order diffraction light ray 110, which are called pits. Since the pits 113a, 113b, and 113c have a different reflectance from that of the surrounding section, when a weak light scans along the center of the track T3, the reflected light is modulated with the pits 113a, 113b, and 113c, and the reproduction signal is obtained.
FIG. 5 is a circuit diagram illustrating the detail of the optical detector 109 shown in FIG. 1 and a signal processing circuit.
In FIG. 5, the optical detector 109 comprises six optical sensors, an optical sensor 115, an optical sensor 116, and a four-divided optical sensor 114 including four optical sensors. The signal processing circuit comprises a differential circuit 119 which receives the outputs of the optical sensors 115 and 116 and outputs a tracking control signal (At); adding circuits 117 and 118 which receive the outputs of the optical sensors diagonally placed in the four-divided sensor 114, respectively; a differential circuit 120 which receives the outputs of the adding circuits 117 and 118 and outputs a focusing control signal (Af); and a adding circuit 121 which receives the outputs of the adding circuits 117 and 118 and outputs an information reproduction signal (RF).
Optical spots 110a, 111a, and 112a indicate that the reflection light rays of the diffraction light rays 110, 111, and 112 enter the corresponding sensors at those points. The optical spot 110a is located nearly at the center of the four-divided sensor 114. The optical spots 111a and 112a are on the optical sensors 115 and 116.
The outputs of the sensors located diagonally in the four-divided sensor 114 are added in the adding circuits 117 and 118, respectively. The outputs of the adding circuits 117 and 118 are added in the adding circuit 121, and an information reproduction signal RF is reproduced. This means that the information reproduction signal RF corresponds to the entire optical spot 110a located on the four-divided sensor 114.
The outputs of the adding circuits 117 and 118 are also input to the differential circuit 120, and this differential circuit 120 finds the difference of them to form the focusing control signal Af. That is, the focusing control signal Af is the difference between the sums of the outputs of the sensors diagonally arranged in the four-divided optical sensor 114. Since the astigmatism method is precisely described in books, its description is omitted here.
The difference between the outputs of the optical sensors 115 and 116 is obtained in the differential circuit 119 to form the tracking control signal At. Control is usually performed such that At becomes zero, thereby performing tracking control for scanning along the information track with light. The information reproduction signal RF obtained in this way is converted to the binary signal for recognizing it as digital information, then this binary signal is sampled with a sampling clock synchronized with the binary signal to generate the data signal.
FIG. 6 is a block diagram illustrating an example of a processing section which converts the information reproduction signal RF to the binary signal and synchronizes the binary signal RF with the clock signal.
The processing section shown in FIG. 6 comprises a comparator 122 which receives the information reproduction signal RF output from the adding circuit 121 shown in FIG. 5 and a reference voltage ref1, and outputs a binary reproduction signal RF2; a PLL control signal generator connected in parallel to the output line of the comparator 122; and a D flip-flop 123 which receives the output of the comparator 122 and a sampling clock SC generated by the PLL control signal generator and outputs the data signal by sampling the binary reproduction signal RF2 with the sampling clock SC.
The information reproduction signal RF output from the adding circuit 121 shown in FIG. 5 is input to the inverting input terminal of the comparator 122 shown in FIG. 6, and compared with the reference voltage ref1 input to the other input terminal of the comparator 122 to form the binary reproduction signal RF2. The binary reproduction signal RF2 generated by this comparator 122 is input to the D flip-flop 123 and the input terminal R of a phase comparator 124.
The reproduction signal RF2 generated by the comparator 122 is input to the D terminal of the D flip-flop 123 and, in order to cope with fluctuation in the scanning speed of the optical spot, is sampled with the sampling clock SC which is almost synchronized with the binary reproduction signal RF2 and is generated in the PLL control signal generator comprising components 124 to 127, described later, to generate the data signal synchronized with the sampling clock SC.
The data signal generated by the flip-flop 123 is generally controlled by the sampling clock SC and stored in buffer memory. Then, the signal is demodulated by a demodulation circuit not shown in the figure and recognized as digital information (reproduction data).
When the binary reproduction signal RF2 generated by the comparator 122 is input to the input terminal R of the phase comparator 124, the sampling clock SC is almost synchronized with the binary reproduction signal RF2 by the phase comparator 124 in conjunction with a charge pump/loop filter 125, a voltage-controlled oscillator (VCO) 126, and a divider 127. The operations of the phase comparator 124, the charge pump/loop filter 125, the voltage-controlled oscillator (VCO) 126, and the divider 127 will be described below in detail.
FIG. 7 is a circuit diagram illustrating the detailed circuit configuration of the phase comparator 124.
The phase comparator 124 comprises a flip-flop 128, a flip-flop 129, and an AND circuit 130. The clock terminal of the flip-flop 128 is connected to the output line of the comparator 122. The non-inverting output Q of the flip-flop 128 is connected to the data terminal of the flip-flop 129. The inverting output terminal Q' of the flip-flop 129 is connected to the reset terminal R of the flip-flop 128. The clock terminal of the flip-flop 129 is connected to the output line (feedback line for the sampling clock SC) of the divider 127 shown in FIG. 6. The AND circuit 130 receives the feedback signal of the sampling clock SC and the signal output from the non-inverting output terminal Q of the flip-flop 129, and outputs a pulse having a half period of the sampling clock SC.
In the phase comparator 124, the binary reproduction signal RF2 output from the comparator 122 is input to the clock terminal of the D flip-flop 128, and the outputs Q and Q' (Q' is the inverted output of Q) are set high and low, respectively. The non-inverting output Q of the flip-flop 128 is input to the input terminal D of the flip-flop 129, and the sampling clock SC is input to the clock terminal CK of the flip-flop 129. The non-inverting output Q of the flip-flop 128 becomes high, setting the outputs Q and Q' of the flip-flop 129 to high and low, respectively.
The inverting output Q' of the flip-flop 129 is connected to the reset terminal of the flip-flop 128 to reset the flip-flop 128. When the flip-flop 128 is reset, the output Q of the flip-flop 128 becomes low, and the outputs Q and Q' of the flip-flop 129 are inverted to low and high, respectively, at the next sampling clock SC.
As described above, in the phase comparator 124, the flip-flop 128 outputs a phase difference (time difference) pulse from the rising edge of the binary reproduction signal RF2 to the rising edge of the sampling clock SC, and the flip-flop 129 outputs a pulse as wide as one period of the sampling clock SC after the binary reproduction signal RF2 goes high. The pulse of one period and the sampling clock SC are gated by the AND gate 130, outputting the pulse D having a half period.
The details will be described later. When the phase of the binary reproduction signal RF2 matches that of the sampling clock SC, the output pulse of the flip-flop 128 has a width half that of the sampling clock SC. When the phase of the sampling clock SC lags against that of the binary reproduction signal RF2, the width of the pulse becomes larger than half of the period of the sampling clock SC, and when the phase of the sampling clock leads, the width of the pulse becomes smaller than half of the period of the sampling clock SC.
Therefore, in the processing section shown in FIG. 6, the output U or U' (U' is the inverted output of U) of the flip-flop 128, which is a phase-lag signal, is used to increase the frequency of the sampling clock SC, and the output D of the AND circuit 130, which is a phase-lead signal, is used to reduce the frequency of the sampling clock SC.
In other words, the phase difference of the sampling clock SC against the binary reproduction signal RF2 is indicated by the pulse width of the output U or U' of the flip-flop 128 in the above-described processing section. To detect a phase lag or phase lead, the output D of the AND circuit 130, which is a pulse having the half width of the sampling clock SC, is referenced.
To reproduce information from a medium in which the information is recorded using the length of a pit or the length of the gap between pits as in the above-described example, the period of the sampling clock SC is, off course, set so that it corresponds to the minimum pit length (hereinafter called 1T) or equivalent. If a track to be reproduced includes a pit or a gap between pits which is longer than 1T, the rising edge of the sampling clock SC does not match the rising (or falling) edge of the binary reproduction signal RF2 at that pit or gap. Because of this, the phases cannot be compared at each sampling clock SC.
To solve this problem, in the example shown in FIG. 7, phase comparison with the sampling clock SC is performed only at the rising edge of the binary reproduction signal RF2, not at each sampling clock SC. An SR flip-flop which is set by the binary reproduction signal RF2 and reset by the sampling clock SC is required to implement this comparison. In the above-described processing circuit, the operation of an SR flip-flop is achieved by feeding back the inverting output Q' of the D flip-flop 129 to the reset terminal of the flip-flop 128 as shown in FIG. 7.
The operation of the charge pump/loop filter 125 at the timing when the two outputs U' and D of the phase comparator 124 are input to the charge pump/loop filter 125 will be described below in detail.
FIG. 8 is a detailed circuit diagram of the most typical charge pump/loop filter used as the charge pump/loop filter 125.
In FIG. 8, the charge pump/loop filter 125 comprises an amplifier 131, diodes, resistors, and a capacitor. The amplifier 131 receives at the inverting input terminal the output U' of the phase comparator 124 with a backward diode D1 and a resistor R1 inserted in series, connected in parallel with the output D of the phase comparator 124 with a forward diode D2 and a resistor R2 inserted in series. The amplifier 131 also receives the reference voltage ref2 at the other input terminal, and outputs a frequency control signal FC, which is fed back to the inverting input terminal of the amplifier 131 with a resistor R3 and a capacitor C1 being inserted in series to the feedback line.
In the charge pump/loop filter 125, the reference input to the amplifier 131 is the reference voltage ref2. When the two outputs U' and D of the phase comparator 124 are both lower than the reference voltage ref2, a current flows from the output of the amplifier 131 through the capacitor C1, the resistor R3, the resistor R1, and the diode D1, charging the capacitor C1, thereby increasing the output of the amplifier 131. In this case, since the diode D2 is arranged in the direction opposed to that of the current flow, the current does not flow into the input D.
On the contrary, when the two outputs U' and D of the phase comparator 124 are both higher than the reference voltage ref2, a current flows from the input D through the diode D2, the resistor R2, the resistor R3, and the capacitor C1 to the output of the amplifier 131, discharging the capacitor C1, thereby reducing the output of the amplifier 131.
The difference between the amounts of charges with which the capacitor C1 is charged and discharged is proportional to the difference between the pulse widths of the two outputs of the phase comparator 124 when the resistor R1 and the resistor R2 are set such that they have the same resistance. When the outputs U' and D of the phase comparator 124 have the same pulse width, the output FC of the amplifier is constant. When the output U' of the phase comparator 124 has a broader pulse width than the output D, the output FC of the amplifier 131 becomes higher. When the output D of the phase comparator 124 has a broader pulse width, the output FC of the amplifier 131 becomes lower.
The output of the charge pump/loop filter 125 is input to the frequency control terminal FC of the voltage-controlled oscillator 126. One of ICs that can be used for this voltage-controlled oscillator 126 is SN74LS624 (product name) of Texas Instrument, which outputs a signal having a frequency proportional to that of the frequency control input FC within the preset frequency range.
The output of the voltage-controlled oscillator 126 is divided in frequency by a factor of 2 by the divider 127 in order to make the duty ratio 1:1. The resultant signal is the sampling clock SC. The obtained sampling clock SC is fed back to the phase comparator 124, and also used as a clock for sampling the binary reproduction signal RF2 in the flip-flop 123. The sampling clock SC is further used as a control signal for buffer memory control and other purposes.
Therefore, when the pulse width of the output U' of the phase comparator 124 is broader than that of the output D, the frequency of the sampling clock SC becomes higher, and when the pulse width of the output U' is smaller than that of the output D, the frequency of the sampling clock SC becomes lower, in the processing section shown in FIG. 6. When the two outputs U' and D of the phase comparator 124 have the same pulse width, the frequency of the sampling clock does not change.
The process in which the sampling clock SC is synchronized with the binary reproduction signal RF2 will be described below in detail.
FIG. 9A is an outlined view of optical-spot scan on pits. FIG. 9B shows the corresponding reproduction signal, and FIG. 9C shows the corresponding binary reproduction signal. FIGS. 9D, 9E, and 9F illustrate the timing of the signals at the terminals shown in FIGS. 6 and 7. FIG. 9D shows the signal timing for the case in which the phase of the binary reproduction signal RF2 match that of the sampling clock SC. FIG. 9E shows the signal timing for the case in which the phase of the sampling clock lags by 0.25T (25%) against that of the binary reproduction signal RF2. FIG. 9F illustrates the signal timing for the case in which the phase of sampling clock leads by 0.25T (25%) against that of the binary reproduction signal Rf2.
In FIG. 9A, pits 113d, 113e, and 113f are pits like the pits 113a, 113b, and 113c shown in FIG. 4, which are optical marks having a lower reflectance than the surroundings. Optical diffraction according to their mechanical shapes, dent or protrusion, may be used for these pits, in addition to the optical density. The pit 113d is a minimum pit having a length of 1T. The pit 113e is twice as wide as the minimum pit, having a length of 2T. The gap between the pits 113d and 113e is a minimum gap, having a length of 1T. The gap between the pits 113e and 113f is twice as wide as the minimum gap, having a length of 2T. This example shows a case in which pit lengths and gap lengths conform to the standard.
When the optical spot moves relative to the recording medium such that the optical spot 110 passes through the pits 113d, 113e, and 113f shown in FIG. 9A in the direction indicated by an arrow, as shown in FIG. 4, the RF signal shown in FIG. 9b is obtained due to a low optical reflectance at the pits. This obtained RF signal is input to the comparator 122 shown in FIG. 6 in order to get the inverted binary reproduction signal RF2 shown in FIG. 9C.
In the case shown in FIG. 9D, the output U of the flip-flop 128 and the output D of the AND circuit 130 have a width of 0.5T, which is half the time (1T) required for scanning the minimum pit length. The rising edge of the sampling clock SC, which is the sampling point in sampling the binary reproduction signal RF2, is located at the center of 1T in each pit or each pit gap, leaving the maximum margin for fluctuation in the scanning speed of the optical spot.
In the case illustrated in FIG. 9E, since the pulse width of the output U of the flip-flop 128 is larger than that of the output D of the AND circuit 130 by 0.25T, the frequency of the sampling clock SC increases so that the sampling clock SC catches up with the binary reproduction signal RF2.
In the case illustrated in FIG. 9F, since the pulse width of the output U of the flip-flop 128 is smaller than that of the output D of the AND circuit 130 by 0.25T, the frequency of the sampling clock SC decreases so that the sampling clock SC shifts backward to match the binary reproduction signal RF2.
In the examples shown in FIGS. 9D, 9E, and 9F, the pit length and pit-gap length conform to the standard. This means that the margin is 0.5T (50%). If the phase of the sampling clock SC shifts by 0.25T (25%) against that of the binary reproduction signal RF2 as shown in FIGS. 9E and 9F, data can be reproduced correctly as 1T, 1T, 2T, and 2T.
In reproducing a signal, when the PLL synchronizing signal starts being input, the sampling clock SC is quickly synchronized with the binary reproduction signal RF2, and RF-signal jitter caused by fluctuation in the scanning speed of the optical spot is followed, as described above. In this process, however, the time constant .tau. of the charge pump/loop filter could not be changed according to conditions, in the conventional system, causing the following problems.
The problems will be described by referring to FIG. 10, which is a graph illustrating a synchronization process in which the sampling clock SC synchronizes with the reproduction signal with different time constants. In FIG. 10, two curves are shown, curve X with a small time constant .tau. of the charge pump/loop filter, and curve Y with a large time constant .tau.. The vertical axis indicates the frequency, the horizontal axis indicates the time required for synchronization, point B indicates the point where the sampling clock SC synchronizes with the binary reproduction signal on the curve X, and point C is the point where the sampling clock SC synchronizes with the binary reproduction signal on the curve Y.
As indicated by the curve X in FIG. 10, when the frequency band in which the operation of the PLL control signal generator is ensured is set to a broad band, that is, the time constant .tau. of the charge pump/loop filter is set small, the response becomes faster, and the sampling clock SC synchronizes with the binary reproduction signal RF2 at the point B where the PLL synchronizing signal is still being input. However, if the reproduction signal is lost due to dust, scratches, or defects on the recording medium, synchronization miss easily occurs, and data cannot be correctly read.
On the other hand, as indicated by the curve Y in FIG. 10, when the frequency band in which the operation of the PLL control signal generator is ensured is set to a narrow band, that is, the time constant .tau. of the charge pump/loop filter is set large, the response becomes slower, and synchronization miss does not occur easily if the reproduction signal is lost due to dust, scratches, or defects on the recording medium during the synchronization process. However, the sampling clock SC cannot be synchronized with the binary reproduction signal RF2 while the PLL synchronizing signal 200 is being input. Therefore, if the synchronization is achieved at point C after the PLL synchronizing signal 200, for example, the data-read-start-position synchronizing signal 201 cannot be detected. In addition, RF-signal jitter caused by fluctuation in the scanning speed of the optical spot cannot be followed, disabling the data to be read correctly after all.

Optical information reproduction apparatus


A method for providing calibration and synchronization pulses in a pulse width modulation (PWM) signal including cell voltage measurement pulses, where the calibration pulses are four calibration pulses having a pattern of a narrow width high voltage pulse followed by a wide width low voltage pulse followed by a narrow width high voltage pulse followed by a wide width low voltage pulse that has a very low probability of occurring in a practical fuel cell system. The method modulates a combined sequence of the voltage measurement signals and the calibration pulses using an inverted saw tooth wave to provide the PWM signal, where a width of the pulses representing the voltage signals are proportional to a width of the pulses representing the calibration pulses.

1. Field of the Invention
This invention relates generally to a system and method for monitoring the cell voltages of fuel cells in a fuel cell stack and, more particularly, to a system and method for monitoring the cell voltages of fuel cells in a fuel cell stack that includes providing calibration pulses before cell voltage measurement pulses in a modulated cell voltage signal, where the calibration pulses have a start of frame sequence defined by a high voltage—a low voltage—a high voltage—a low voltage pattern that will not be reproduced by normal cell voltage measurements.
2. Discussion of the Related Art
Hydrogen is a very attractive fuel because it is clean and can be used to efficiently produce electricity in a fuel cell. A hydrogen fuel cell is an electro-chemical device that includes an anode and a cathode with an electrolyte therebetween. The anode receives hydrogen gas and the cathode receives oxygen or air. The hydrogen gas is dissociated in the anode to generate free protons and electrons. The protons pass through the electrolyte to the cathode. The protons react with the oxygen and the electrons in the cathode to generate water. The electrons from the anode cannot pass through the electrolyte, and thus are directed through a load to perform work before being sent to the cathode.
Proton exchange membrane fuel cells (PEMFC) are a popular fuel cell for vehicles. The PEMFC generally includes a solid polymer electrolyte proton conducting membrane, such as a perfluorosulfonic acid membrane. The anode and cathode typically include finely divided catalytic particles, usually platinum (Pt), supported on carbon particles and mixed with an ionomer. The catalytic mixture is deposited on opposing sides of the membrane. The combination of the anode catalytic mixture, the cathode catalytic mixture and the membrane define a membrane electrode assembly (MEA). MEAs are relatively expensive to manufacture and require certain conditions for effective operation.
Several fuel cells are typically combined in a fuel cell stack by serial coupling to generate the desired power. For example, a typical fuel cell stack for a vehicle may have two hundred or more stacked fuel cells. The fuel cell stack receives a cathode input reactant gas, typically a flow of air forced through the stack by a compressor. Not all of the oxygen is consumed by the stack and some of the air is output as a cathode exhaust gas that may include water as a stack by-product. The fuel cell stack also receives an anode hydrogen reactant gas that flows into the anode side of the stack. The stack also includes flow channels through which a cooling fluid flows.
The fuel cell stack includes a series of bipolar plates positioned between the several MEAs in the stack, where the bipolar plates and the MEAs are positioned between the two end plates. The bipolar plates include an anode side and a cathode side for adjacent fuel cells in the stack. Anode gas flow channels are provided on the anode side of the bipolar plates that allow the anode reactant gas to flow to the respective MEA. Cathode gas flow channels are provided on the cathode side of the bipolar plates that allow the cathode reactant gas to flow to the respective MEA. One end plate includes anode gas flow channels, and the other end plate includes cathode gas flow channels. The bipolar plates and end plates are made of a conductive material, such as stainless steel or a conductive composite. The end plates conduct the electricity generated by the fuel cells out of the stack. The bipolar plates also include flow channels through which a cooling fluid flows.
As a fuel cell stack ages, the performance of the individual cells in the stack degrade differently as a result of various factors. There are different causes of low performing cells, such as cell flooding, loss of catalyst, etc., some temporary and some permanent, some requiring maintenance, and some requiring stack replacement to exchange those low performing cells. Although the fuel cells are electrically coupled in series, the voltage of each cell when a load is coupled across the stack decreases differently where those cells that are low performing have lower voltages. Thus, it is necessary to monitor the cell voltages of the fuel cells in a stack to ensure that the voltages of the cells do not drop below a predetermined threshold voltage to prevent cell voltage polarity reversal, possibly causing permanent damage to the cell.
Typically, the voltage output of every fuel cell in a fuel cell stack is monitored so that the system knows if a fuel cell voltage is too low, indicating a possible failure. As is understood in the art, because all of the fuel cells are electrically coupled in series, if one fuel cell in the stack fails, then the entire stack will fail. Certain remedial actions can be taken for a failing fuel cell as a temporary solution until the fuel cell vehicle can be serviced, such as increasing the flow of hydrogen and/or increasing the cathode stoichiometry.
Fuel cell voltages are often measured by a cell voltage monitoring sub-system that includes an electrical connection to each bipolar plate, or some number of bipolar plates, in the stack and end plates of the stack to measure a voltage potential between the positive and negative sides of each cell. Therefore, a 400 cell stack may include 401 wires connected to the stack. Because of the size of the parts, the tolerances of the parts, the number of the parts, etc., it may be impractical to provide a physical connection to every bipolar plate in a stack with this many fuel cells, and the number of parts increases the cost and reduces the reliability of the system.
As discussed above, it is known in the art to process the voltages of the fuel cells in a fuel cell stack to determine whether the fuel cell stack is functioning as desired. Sometimes, cell voltage processing is performed every other cell because of the costs associated with monitoring every cell. Furthermore, it can be difficult to provide the necessary components in the space available to monitor every cell. In order to eliminate the need to connect fuel cell measurement circuits to a fuel cell stack using a plurality of interconnecting wires, it is desirable to embed such measurement circuits directly within the structure of the fuel cell stack assembly. Such an embedded measurement circuit would not add significant cost, and would allow for every fuel cell to be monitored.
U.S. patent application Ser. No. 12/840,047, titled Stack-Powered Fuel Cell Monitoring Device With Prioritized Arbitration, filed Jul. 20, 2010, assigned to the assignee of this application and herein incorporated by a reference, discloses a system and method for monitoring the cell voltages of fuel cells in a fuel cell stack. The system includes a plurality of voltage sensors coupled to the fuel cells in a fuel cell group, and a plurality of oscillators, where a separate oscillator is coupled to each of the sensors. Each oscillator operates at a different frequency, where higher frequency oscillators are coupled to lower priority sensors and lower frequency oscillators are coupled to higher priority sensors. The system also includes a light source, such as an LED, that receives frequency signals from the oscillators, where the light source switches on and off in response to the frequency signals and where lower frequency signals dominate the switching of the light source. A light pipe receives the switched light signals from the light source and provides light signals at a certain frequency at an end of the light pipe. A photodetector detects the light signals at the end of the light pipe.
The system disclosed in the '047 application for monitoring cell voltage has limitations in accurately providing the cell voltage, as do most other known cell voltage monitoring systems. As the fuel cell industry progresses, it is desirable to provide at least a 10-15 mV resolution accuracy of the voltages measured from the fuel cells. So far, this level of accuracy has been difficult to achieve using standard automotive sensors and parts. If the cell voltages are not accurately represented, then control of the various fuel cell system operations is limited in its accuracy, which could result in lower system performance, inefficiencies, cell degradation, etc. Further, prior cell voltage monitoring systems typically allowed the monitoring device to identify a minimum cell voltage, a maximum cell voltage and an average cell voltage, but were unable to identify which voltage was associated with which cell. It would be advantages to have this information so that a technician can identify a specific cell that may be failing.

This patent is subject to a terminal disclaimer.

Frame sequence for a cell voltage measurement system with a low probability of natural occurrence


A conditional purchase offer (CPO) management system is disclosed for receiving CPOs from one or more customers, such as airline passengers, and for evaluating the received CPOs against a number of CPO rules defined by a plurality of sellers, such as airlines, to determine whether any seller is willing to accept a given CPO. A CPO is a binding offer containing one or more conditions submitted by a customer for purchase of an item, such as airline travel, at a customer-defined price. A CPO rule is a set of restrictions defined by a given seller, such as an airline, to define a combination of restrictions for which the seller is willing to accept a predefined price. The CPO rules may be securely stored by one or more servers. The CPO management system permits a seller to correct for forecasting errors, if necessary, or other competitive forces which have produced excess capacity, by providing inventory for sale to CPO customers.

Airlines and other sellers have developed sophisticated revenue management systems (RMSs) to optimize revenue. Generally, when a flight is first added to an airline's flight schedule, the airline's revenue management system attempts to maximize revenue for the flight by establishing a plurality of fare classes and then allocating the number of seats and price assigned to each fare class. The revenue management system will thereafter continue to monitor the actual demand within each fare class relative to forecasted demand, to dynamically reevaluate the inventory allocation and pricing of each fare class for a given flight. In this manner, the airlines attempt to fly each aircraft as full as possible without allowing earlier-booking discount-fare passengers to displace later-booking full-fare passengers.
While conventional revenue management systems employ sophisticated tools to anticipate future travel, forecasting errors invariably lead to unanticipated excess capacity. In addition, an airline can utilize its revenue management system to forecast its anticipated excess capacity on a given flight associated with seats that are predicted to be empty. Furthermore, unexpected external events, such as a price war or extreme weather conditions, can also affect an airline's excess capacity. Thus, in an attempt to reduce such excess capacity, airlines periodically reevaluate the inventory allocation and pricing of each fare class for a given flight. An airline cannot simply discount the published fares for such unsold seats, however, without either starting a fare war or compromising its own underlying fare structure (i.e., without also reducing its full-fare prices for business travelers). Thus, there is currently no effective way for airlines to dispose of such excess capacity.
Although many airlines fill empty seats with "standby" passengers, this practice is typically limited to instances where some oversight on the part of either the passenger or the airline has occurred. For example, the passenger's flight may have been overbooked, the passenger may have missed an original flight, or the passenger may have purchased a ticket at or near the time of the flight. Moreover, standby travel is costly for the airline and is inconvenient for the passenger because there is no guarantee that the passenger will get to fly on the same day.
In addition, airlines attempt to sell excess capacity utilizing consolidators, who traditionally sell airline tickets at a discount. Since the terms of the relationship between the airlines and the consolidators are generally not flight specific and are typically defined months in advance, the sale of tickets through a consolidator does not provide a sufficiently dynamic mechanism for airlines to sell such excess capacity when actual demand fails to meet forecasted demand. Even assuming that the airlines could release the tickets for sale through the consolidators at the last minute, there is currently no effective way for the consolidators to announce the availability and price of such tickets to customers.
Airlines recognize that there is a large source of latent demand associated with leisure travelers who are willing to purchase tickets at a favorable price. There is currently no effective way, however, for an airline to receive an offer from a customer for leisure travel at a particular price set by the customer, below the airline's published fare. In particular, there is no effective way for the airline to be confident that if the airline accepts the customer's offer, the customer will book the ticket without using the information to ascertain the airline's underlying level of price flexibility, which, if known to an airline's competitors or customers, could dramatically impact the airline's overall revenue structure.
As apparent from the above deficiencies with conventional systems for selling goods and services, such as airline tickets, a need exists for a system that permits a seller to sell excess capacity when actual demand fails to meet forecasted demand. A further need exists for a buyer-driven system that permits an airline to sell tickets to leisure travelers at a price set by the customer, typically below the airline's published fare. Yet another need exists for a system that permits sellers to stimulate sales of excess inventory, without compromising the seller's published price structure. Another need exists for a system that permits sellers to capture and process consumer demand for each selling price of a given item, such as a given fare class on each airline flight.

Conditional purchase offer management system


Provided are an organic light-emitting compound represented by Formula 1 and an organic electroluminescent (EL) device using the same:

1. Field of the Invention
The present invention relates to an organic light-emitting compound and an organic electroluminescent (EL) device using the same, and more particularly, to an organic light-emitting compound which has superior electric features, thermostability, and photochemical stability, and can accomplish low driving voltage, high efficiency, and superior color purity of organic electroluminescent devices, and to an organic EL device using the same.
2. Description of the Related Art
An electroluminescent (EL) device is a self-emitting device which has a wide viewing angle, excellent contrast, and quick response time. EL devices can be classified into inorganic EL devices which use inorganic compounds for emissive layers and organic EL devices which use organic compounds for emissive layers. Compared to inorganic EL devices, organic EL devices have superior luminance, lower driving voltage, and quicker response time, and can realize multicolor images.
A typical organic EL device has a stacked structure in the form of an anode/organic emissive layer/cathode structure. Organic EL devices can also have an anode/hole-injection layer (HIL)/hole-transport layer (HTL)/emissive layer/electron-transport layer (ETL)/electron-injection layer (EIL)/cathode structure, or an anode/HIL/HTL/emissive layer/hole-blocking layer/ETL/EIL/cathode structure.
Materials used in organic EL devices can be classified into vacuum deposition materials and solution coating materials. Vacuum deposition materials should be able to have a vapor pressure of 10−6 torr or higher and may be small molecular materials having a molecular weight of 1200 or less. Solution coating materials should have sufficient solubility and usually include aromatic compounds or heterocyclic compounds.
Manufacturing organic EL devices using vacuum deposition increases costs due to the use of a vacuum system. In addition, when shadow mask is used to manufacture pixels for natural color display, manufacturing high resolution pixels is difficult.
On the other hand, manufacturing organic EL devices using solution coating methods such as inkjet printing, screen printing and spin coating is easy, costs less, and can accomplish relatively higher resolution than using shadow mask.
However, in terms of thermostability and color purity, blue light emitting molecules of solution coating materials are inferior to vacuum deposition materials. Also, as crystallization occurs after manufacturing, crystals as large as wavelengths of visible light disperse visible light and cause white residue. In addition, pinholes are formed and deteriorate the devices.
Japanese Patent No. 1999-003782 discloses two naphthyl-substituted anthracene compounds as compounds for emissive layers or hole injection layers. Also, Japanese Patent Nos. 2004-091334 and 2003-146951 disclose a triphenylamine-substituted anthracene compound for emissive layers or hole injection layers. However, solvent solubility of the above two compounds are not high enough to form layers and thus features of the resulting organic EL devices using the above two compounds are not satisfactory.
Thus, an organic EL device using blue light emitting compounds which are thermostable and suitable for forming layers, which has low driving voltage, superior luminance, high efficiency and superior color purity, is required.

Organic light-emitting compound and organic electroluminescent device using the same

Abstract: The organic light-emitting compound has thermostability and photochemical stability in addition to superior electrical features. The organic EL device using the organic light-emitting compound has low driving voltage, high efficiency, and superior color purity.


Disclosed is an actuator for axial displacement of an object, including an actuator piston disc displaceable in a cylinder volume, an inlet channel, a first inlet valve body arranged in the inlet channel, a second inlet valve body operatively connected to the actuator piston disc and arranged in the inlet channel, an outlet channel and an outlet valve body arranged therein. The actuator includes an electrically controlled pilot valve communicating a first control pressure to the first inlet valve body via a first control pressure channel and communicating a second control pressure to the outlet valve body via a second control pressure channel. The pilot valve places itself in either a resting state or an active state.

Thus, an actuator, commonly known as a pneumatic actuator, comprises an actuator piston disc that is displaceable in axial direction between a first position (inactive position) and a second position (active/extended position). The displacement is achieved by controlling a supply of pressure fluid, such as pressurized gas/air, that acts on the actuator piston disc. The actuator piston disc in turn directly or indirectly acts on the object that is to be displaced, for example an engine valve, for controlling its position.
When the actuator piston disc is in the inactive position the engine valve is in contact with its seat, and when the actuator piston disc is in the active position the engine valve is open, i.e. situated at a distance from its seat.
In the applicants own document WO 2013-058704 an actuator is described in which a pressure pulse, which is started by a first inlet valve body opening and allowing pressure fluid from a pressure fluid source to act on and drive the actuator piston disc from its resting position, is stopped by a second inlet valve body, that is rigidly connected to and jointly displaceable with the actuator piston disc, cutting the flow from the pressure fluid source and thereby closes the inlet channel. This construction provides a direct correlation between the pulse length and the travel that the actuator piston disc performs.
Nevertheless, the valve bodies that open/close the inlet channel and the outlet channel have in this publication relatively large mass and small throughput areas. It is also known that some applications demand high working pressure/high pressure, for example 20-25 Bar, to achieve a correct function of the actuator, i.e. to unction together with internal combustion engines with a range of number of turns up to 8-10 thousand turns per minute. There is further a wish to avoid that the temperature rises in the actuator and the surrounding parts/fluids in such applications as a result of the very operation of the actuator and the accompanying compressor, and this is achieved by holding a pressure relation low and thereby a so called enhanced return pressure is used, also known as low pressure/base pressure. In other words the pressure of the pressure fluid that is located downstream from the actuator and upstream from the compressor is much higher than the atmospheric pressure, for example 4-6 Bar. The relatively large mass of the valve bodies results in that the valve bodies risk to rebound from their seats when they shall place themselves in their respective resting positions, whereby jarring and vibrations arise and/or the included parts are damaged, and lead to imprecise control of the pressure fluid in the inlet channel and the outlet channel, respectively.
The relatively small throughput areas in combination with the high return pressure lead to, at the return of the actuator to the inactive position, the evacuation of the pressure fluid from the cylinders first portion risks to be insufficient, which leads to a slow return of the actuator piston disc.

Actuator for axial displacement of an object


An improved fibrous composite structure for use in grinding, cutting and/or polishing operations, normally with abrasives. Webs of fibrous materials, preferably blends of fibers having different deniers are fed to a needling apparatus and are needled, starting with at least two such webs. The needles force fibers from the webs along the path of needle travel and withdraw generally clean, leaving voids that define pores. Further individual layers are needled in like fashion to alternating opposite sides of the structure. Needles pass through an amount greater than fifty percent of the then thickness of the structure adequate to produce a unitary composite, though, and most preferably entirely through the thickness. The process for producing the composite products and embodiments of the products are also disclosed and claimed.

The present invention relates to fibrous products for use in the polishing or other treatment of surfaces with abrasives, chemicals, and the like and to processes for producing same.
Industry has for many years utilized techniques for cutting and polishing glass, metals, stones, crystals and the like in which a pad, substrate or the like is applied against a surface to be treated and with an abrasive material such as cerium oxide, aluminum oxide and the like located therebetween, normally in a slurry form. Pressure applied by the polishing pad or other substrate against the abrasive matrials carried by the slurry imparts a cutting affect on the surface, and depending upon the parameters of the process, a surface being treated may be cut, ground, and/or polished. In similar fashion certain polishing operations have been conducted with chemical formulations only.
Materials to be cut, ground or polished are virtually limitless and include metals, glasses, polymeric compositions, stones, ceramics, crystals and the like. The degree of cutting, grinding and/or polishing is determined by the particular abrasives being used, the particular pads or substrates employed and the particular pressures involved to achieve the desired result.
Certain techniques are designed solely to present a product having a pleasing, aesthetic surface. In many other cases, however, significant criticality is attached to the ultimate finished surface to enable the article or product to function as intended, such as for example, picture tubes for television sets or other video equipment, optical lenses, gem stones, electronic components, and the like, including initial preparation as well as removal of defects therefrom.
The polishing pads are substrates used in the manner aforesaid, and have taken various and sundry forms from a flat planar surface having a predetermined shape to endless bands and/or discrete particles secured to a rotary support member. Likewise, when the particular product or article to be ground and/or polished has a particular three-dimensional shape as opposed to a planar surface, such often dictates the particular size, shape, and/or configuration of the polishing pad that is to be employed.
Many attempts have heretofore been made to fabricate polishing pads of various and sundry shapes and materials to accommodate for the wide variety of uses noted above, and in general, have succeeded in affording some economic and/or technical improvement in the then state of the art processes. Though such improvements have heretofore been made, problems continue to exist for various and sundry reasons. Notably, needled natural and synthetic fibrous felts have been produced and utilized as polishing pads though historically such products have been lacking in uniformity of density, porosity, and the like. Furthermore, historically there have been limits to the thickness of such needled fibrous products though attempts have been made to tack plural layers together to build up a thicker composite polishing pad. Under such tacking conditions needling into adjacent fibrous layers is limited, however, and discrete layers remain with a lack of total cohesiveness therebetween leading to possible delamination of the polishing pad which, of course, would require discarding of same, and may destroy the product or products being treated.
Other attempts have been made to produce composite pads in which discrete fibrous layers have been adhesively secured together. Again, the adhesive interfacial layers present a different effect in the working of abrasives or the like across a work surface than the fibrous pad, leading to possible changes in surface characteristics. Likewise, adhesive bonds are subject fo fail, leading to delamination with same attendant results as noted above.
Other techniques utilized in producing fibrous polishing pads include the carding or other aligning of batts of fibers followed by needling of the batt. Certain of the batts have been built up by the cross-lapping of fibrous webs, followed by needling once the webs of desired thickness weight or the like was obtained. These types of technique are limited to very thin products due to initial fiber bulk.
In still other operations, attempts have been made to orient the fibers in a polishing pad to enhance the effective use of same.
All in all, therefore, considerable effort has been expended in attempting to improve the art of fibrous pads or structures for use in cutting, grinding or polishing of various surfaces.
In recent years, following at least the advent of the poromeric synthetic leather materials the fibrous pads or substrates have been impregnated with porous elastomeric materials. The elastomeric materials employed have often been urethane based and have been variously applied to the fibrous materials from both solvent and aqueous systems. Key to application of the elastomeric materials has been placement of the cured elastomer throughout the fibrous base with a proper field of pores, normally microscopic in size to achieve a uniformly impregnated structure with uniform porosity.
Porosity becomes important in actual use of the finished product in the mechanism of working of the abrasives across the work surface. Notably, as the pad is moved under pressure across the work surface, porosities of the pad continually pick up and expel abrasive slurry in a "pumping action" which adds to uniformity of the action.
Other known-prior art includes U.S. Pat. Nos. 3,000,757; 3,067,483;, 3,100,721; 3,180,853; 3,208,875; 3,284,275; 3,536,553; 3,499,250; 3,504,457; 3,581,439; and 4,728,552, all of which relate to fibrous substrates impregnated with elastomeric materials for polishing operations and the like.
The fibrous structure of the present invention, represents improvement over all of the above prior art and is neither taught nor suggested thereby.

Products for use in polishing and the like and process for producing same


An apparatus for identifying plant varieties from leaf or flower samples taken while in the field comprises a scanning device having a backlight so as to enable a detailed image of a sample to be recorded digitally, a computer for uploading the image for analysis, a computer program which allocates user prescribed parameters such as leaf venation, leaf shape, base position and shape and leaf curvature to the image, and utilizing the data produced by the computer program and applying an algorithm to it for matching the data against a database of plant varieties to determine the highest match probability.

Botanists typically spend a large amount of time in the field collecting samples for their research. Historically botanists have relied upon textbooks and compendiums of plant samples to correctly identify plant varieties from leaf and flower samples. The identification of plant varieties from leaf samples is based upon a close examination of leaf venation patterns, the configuration of leaf shapes and other identifying features and matching observed but unknown features with known specimens, photographs, illustrations or descriptions.
Recent developments in computer and electronic technological fields have meant that access to digitally stored data is more readily available. Further, computer chip processing speeds and memory storage capacities have increased significantly such that it is now possible to store within a relatively small sized device a large volume of digital data or to access remotely stored data using wireless communication means. The integration of such technology with plant identification and classification algorithms is now possible and desirable as a means of facilitating the ease by which botanists might accurately identify plant samples whilst engaged in field work.
It would be advantageous to develop an apparatus and method for correctly identifying plant varieties whilst in the field based upon an examination of leaf samples which employs a suitably designed and configured electronic device. This could greatly improve the productivity of botanists engaged in field research and reduce the overall costs of undertaking such research. Such an apparatus and method may have other uses outside the field of botanical research, for example, in correctly identifying a plant type in the case of a patient experiencing an allergic reaction to a plant which may potentially be life threatening. In such circumstances the apparatus and method for identifying plant varieties may be very valuable in preserving life or in accurately diagnosing a particular medical condition and prescribing a suitable prophylaxis or remedy.
There are a number of prior art apparatuses and methods for identifying plants through leaf venation. On the "Leafsnap" website for example, there is described an application suitable for use on an i-Phone for identifying leaves which involves taking photographs of leaf samples and matching the photograph of the sample to existing photographs stored within a database. The application compares the outline of the sample leaf or flower which is not sufficiently accurate to enable correct identification of plant species to the degree required of a botanist. The application is suitable for hobbyists.
US Patent 20080059076 describes a method for classifying leaves utilizing venation features. The method includes taking a sample venation image using a Curvature Scale Space Corner Detection Algorithm. The image is then treated to thicken the venation and increase the contrast through the retrieval unit. Canny Edge Detection technology is then applied to detect the feature, branching and end points where the calculated curvature angle is a local maximum. The distribution of the feature points of the extracted venation is calculated by applying a Parzen Window non-parametric estimation method.
Existing methods of identifying plant varieties from leaf and flower samples including those referred to above however suffer from a lack of accuracy and ease of use, particularly in field situations. The method described in US 20080059076, for instance, focuses on the process of categorising leaf venation into 4 categories: pinnate, first parallel, second parallel and palmate. It assumes that the image has been captured and does not make mention as to how the exact type of leaf is determined once it has been classified into one of the four categories employed. There is a lack of cross-reference to other characteristic features of the samples examined and no overriding means of enhancing the accuracy of data captured.
The use of photographic devices to capture leaf images is known. The use of scanning devices to capture leaf images for the purpose of identification is also known known however hitherto apparatus and methods for enabling identification of plant varieties from leaf samples are inefficient and subject to a significant degree of error so as to make their use commercially unviable. Particularly, images produced by known apparatus and methods are of insufficient contrast, detail and clarity and do not produce image data which can be readily and effectively applied to assist identification of a subject plant species. It would be advantageous to provide an apparatus and method for identifying plant varieties from leaf samples which produced enhanced images for analysis in order to alleviate the large margin for error in identifying the leaf species using available apparatus and techniques. Such an apparatus and method would greatly reduce the time necessary to accurately identify a plant variety from a leaf sample, and image produced therefrom and would also significantly reduce the financial costs of providing such a service.
It would be advantageous to provide an apparatus and method for identifying plant varieties from leaf samples which overcomes at least some of the problems of prior art devices and which provided for greater accuracy in identification of samples.
Accordingly there is provided an apparatus for identifying plant varieties from leaf samples taken whilst in the field comprising:
a scanning device having an image sensor and an LED backlight so as to enable a detailed image of a sample to be recorded digitally;
a computer for uploading the image for analysis;
a computer program which allocates user prescribed parameters such as leaf venation, leaf shape, base position and shape and leaf curvature to the image;
utilising the data produced by the computer program and applying an algorithm to it for matching the data against a database of plant varieties to determine the highest match probability.
In some preferred embodiments the apparatus is a hand-held or laptop computer.
There is provided a method for identifying plant varieties from leaf samples taken whilst in the field including the steps:    (i) acquiring a scanned image of a leaf sample using an apparatus comprising an LED back lit scanning device having an image sensor and an LED backlight and a computer for uploading the image for analysis;    (ii) applying an image manipulation algorithm to the scanned image to enhance venation data recorded;    (iii) producing a venation line drawing;    (iv) cross-referencing venation line drawing data with a set of identification data;    (v) comparing venation and identification data with known samples stored in a database;    (vi) choosing and displaying the most probable match for plant variety according to the sample analysis.
There is also provided a method for identifying plant varieties from leaf samples taken whilst in the field including the steps:    (i) harvesting a leaf sample;    (ii) taking a photographic image of the leaf sample using a back lit scanning device having an image sensor and an LED backlight;    (iii) extracting a set of identification parameters from the photographic image including leaf venation, leaf shape, base position and shape and leaf curvature;    (iv) applying an identification algorithm to the extracted identification parameters;    (v) presenting the results of the algorithmic analysis on a screen of a computer or hand held device;    (vi) comparing the sample with illustrations of known leaf samples;    (vii) choosing and displaying the most probable match for plant variety according to the sample analysis.

Apparatus and method for identifying plant varieties from leaf samples taken whilst in the field


The invention is a trailer designed for use with catamarans and perhaps other multi-hull vessels which are intended to be trailed on the highway but have a beam when sailing much broader than the permissible widths of vehicles allowed on the highway, so that the hulls are separate and can be collapsed together for trailing, and expanded to the proper width and assembled with frame support members when ready to sail. The trailer is designed to carry this type of vessel and has a pair of elongated cradles mounted on the ends of outrigger beams which are swung outwardly to put the hulls at the proper spacing for attachment for sailing, with the outrigger beams being swung inwardly by a central traveling beam to which they are pivoted to draw the cradles together side by side in transport-ready position on the trailer.

Multi-hull vessels have experienced a tremendous popularity in recent years. In their initial stages of development, these vessels were provided either as large boats which could only be maintained at a slip or dock space in the water, or the much smaller catamaran which could be trailed on the highway. Because of the much wider beam of the catamaran compared to a conventional sailboat, only very small boats of the multi-hull variety could previously be trailed on the highway. As the cost of permanent dock space continues to sharply increase, maintaining a multi-hull vessel at a dock has become prohibitively expensive for many spare time sailors, resulting in the demand for various means to trail middle-sized catamarans so that they would not have to be kept at a dock.
The patent literature is replete with not only different trailer styles, but some rather involved hull designs and overall multi-hull vessel configurations which permit collapsing and towing of these vessels. Another approach, used for catamarans slightly larger than the readily trailable variety, is to elevate one hull reltative to the other on a trailer and tow the vessel at a steep sideways slope.
A solution which involves the present invention directly is a catamaran having a beam of 17 to 20 feet, which is obviously a great deal wider than the 8 foot maximum width permitted on most highways. This vessel has a pair of hulls which are strapped to cylindrical cross beams which maintain the 17 to 20 foot spacing when the vessel is in use sailing. These cross beams are unstrapped and a pair of short beams of the same diameter are substituted to keep the hulls together when they are separated from the main beams and collapsed together side by side for towing on a specially made trailer. This vessel is a wonderful sailer and can be conveniently towed on the highways so that the conflicting criteria of trailability versus wide beam have been eliminated by merging the advantageous characteristics of both types of vessel in a single boat. There remains one large disadvantage to this vessel, however, which the present invention is designed to eliminate. This disadvantage is the very long time, at least two hours for two people, which is required to assemble the boat at the launch site. Although this is caused by a number of factors, one major contributory factor is the requirement that the boat be assembled in its hull-together mode on board the trailer and launched in this barely seaworthy condition, with the hulls being later separated by forcing them apart on the long cross beams once the hulls are afloat. In addition to the likelihood of loss of small parts and other mishaps trying to accomplish this operation afloat, it is easy to understand that while crouched on a narrow hull in a choppy sea the problems of assembling the boat in expanded form are much exaggerated compared to the same operation if it could be performed in the comfort and safety of a land environment.


Novel thermally stable bisimido/allylaniline polymers and prepolymers, well adopted for the production of prepregs and reinforced and impregnated composite shaped articles, comprise the copolymerizates of (a) at least one N,N'-bisimide, with (b) at least one hindered p-allylaniline, optionally in the presence of (c) an organic peroxide, azobisisobutyronitrile or an imidazole, (d) a vinylpyridine, N-vinylpyrrolidone, allyl isocyanurate, vinyltetrahydrofuran, or mixture thereof, (e) at least one diprimary diamine, and/or (f) an unhalogenated or chlorinated/brominated epoxy resin or N,N'-alkylenebistetrahalophthalimide, or particular (meth)acrylate or alkenylphenol.

1. Field of the Invention
The present invention relates to novel thermally stable bisimido/p-allylaniline copolymers and to the preparation of such novel copolymers.
2. Description of the Prior Art
Polymers prepared by reacting an N,N'-bisimide of an unsaturated dicarboxylic acid, such as, for example, an N,N'-bismaleimide, with a diprimary diamine (French Patent No. 1,555,564) are known to this art. The amounts of N,N'-bisimide and diamine are selected such as to provide a ratio: number of moles of bisimide/number of moles of diamine equal to at least 1; furthermore, it is generally preferred that such ratio be lower than 50. Thermally stable resins are produced, which display marked resistance to severe thermal stresses.
In the aforementioned French Patent, it is also indicated that the preparation of these resins may be carried out in bulk, by heating reactants which have been thoroughly mixed beforehand, or in an inert polar diluent such as dimethylformamide, N-methyl-pyrrolidone or dimethylacetamide, it being possible for the latter process to be used, for example, when the application of the polymer makes it necessary to employ a solution thereof.
Finally, it too is indicated that, for many applications, it is advantageous to conduct the polymerization in two steps; in a first stage, a prepolymer is prepared by heating a thorough mixture of the two reactants to a temperature on the order of 100.degree. to 250.degree. C. The prepolymer obtained may be employed in the form of a solution, suspension or powder, or else may also be shaped merely by being cast hot. In a second stage, curing of the prepolymer may be effected by heating it to temperatures on the order of 350.degree., optionally under pressure.

Thermally stable bisimido/p-allylaniline copolymers


An edge detecting apparatus for using in an automatic device and configured for detecting edges of a surface on which the automatic device moves is provided. The edge detecting apparatus includes an emitter, a guiding member, and a receiver. The emitter is configured for emitting projecting signal. The guiding member is around the automatic device. The guiding member and the surface define a signal channel, and the signal channel is configured for guiding the projecting signal to travel around the automatic device, if no edge of the surface exists under the signal channel. The receiver is configured for receiving the projecting signal.

1. Technical Field
The present disclosure relates to detecting apparatus and, particularly, relates to an edge detecting apparatus.
2. Description of Related Art
Many automatic devices, such as robots, dust collectors and toys, employ edge detecting apparatuses to detect edge(s) of a surface on which the automatic devices move. Current edge detecting apparatuses include an emitter and a receiver. The emitter is configured for emitting projecting signals, e.g., light ray or radio wave, to the surface. The receiver is configured for receiving the reflected projecting signals. One of the disadvantages of the current edge detecting apparatuses is an inordinate number of edge detecting apparatuses are required for each device, as a result, the cost of the automatic device increases.
What is needed, therefore, is an edge detecting apparatus to overcome the above mentioned problem.

Edge detecting apparatus and automatic device with same

Hong Fu Jin Precision Industry (ShenZhen) Co., Ltd.


Information can be transported over domains operated by different service providers at required Quality-of-Service (QoS) levels without disclosing inter- and/or intra-domain information to ensure that the topology of a given service provider's domain (e.g., network) is not disclosed.

Assuring that information is transported from one point to another with a certain quality-of-service ("QoS"), especially when the points are located in different domains (i.e., inter-domain) operated by different service providers, is important to the success of existing services as well as to enable the spread and growth of relatively new services, such as voice-over-Internet protocol ("VoIP"), multimedia and mission-critical services.
While the transport of information within a single domain (i.e., intra-domain) at certain guaranteed QoS levels has been the subject of considerable research for over a decade, little research has been done on the transport of information at certain guaranteed QoS levels in the inter-domain setting.
The transport of information over different domains involves issues that are not present in the intra-domain setting. For example, typically a service provider operating one domain (sometimes referred to as an "Autonomous System or "AS") requires that its internal topology (e.g., path segments, links) be kept secret from all other service providers. Hereafter, we will use the terms "domains", "AS", and "network" to mean the same thing, that is, the physical infrastructure that is built, operated and maintained most often by a single service provider (e.g., Verizon).
Accordingly, it is desirable to provide methods and devices that enable the transport of information between different domains while assuring QoS levels and maintaining intra-domain, topological secrecy.

Methods and devices for computing paths to assure the inter-domain transport of QoS sensitive information


An imaging device includes a plurality of photoelectric converting units arrayed in the horizontal and vertical directions, and an adder for adding signals including the same color component from the a plurality of photoelectric converting units such that the centers of gravity of the signals after addition are at the same pitch for respective signals.

1. Field of the Invention
The present invention relates to an imaging device for taking images of a subject.
2. Description of the Related Art
In recent years, imaging elements having up to ten million pixels have been employed for digital still cameras of which primary usage is taking still images, and also imaging elements having several million pixels have been employed for movie cameras of which primary usage is taking moving images. With the above-described usages, in general, taking images has been performed with the high number of pixels in the event of taking high-definition images required for high resolution, and with the low number of pixels in the event of low resolution. In this process, in the event of taking high-definition images, generally all pixel signals have been read out from the imaging elements, and in the event of taking low-resolution images, pixel-signal thinning-out readout and readout for performing both pixel-signal thinning-out and addition, have been performed either to prevent the camera from excessive battery consumption, or to increase the number of shots. Examples of the above-described conventional arrangements include Japanese Patent Laid-Open No. 9-247689 and Japanese Patent Laid-Open No. 2001-36920.
With the arrangement disclosed in Japanese Patent Laid-Open No. 9-247689 (FIG. 3 in the Publication), readout addition is performed by thinning out the same color in increments of 4×4 pixels.
With the arrangement disclosed in Japanese Patent Laid-Open No. 2001-36920 (FIG. 1 in the Publication), a plurality of pixel signals are added, with 4×4 pixels making up one group, such that spatial color array of each color is the same before and after addition.
With Japanese Patent Laid-Open No. 9-247689, the number of valid pixels used in 4×4 pixels is few. Recent imaging elements have reduced unit-pixel size owing to high pixelation, and insufficient sensitivity is becoming a more prominent issue. With digital still cameras, while insufficient sensitivity in shooting of a dark subject can be compensated for with flash emission, taking moving images generates a great amount of noise since an expensive and heavy light source cannot be used. Furthermore, moiré occurs due to deterioration of image sampling frequency owing to pixel-signal thinning-out, resulting in marked deterioration of image quality.
With Japanese Patent Laid-Open No. 9-247689, while sensitivity can be improved by increasing the number of pixel signals to be added within one group, a problem is to provide pixel signals, which are not used (discarded). Moreover, while a plurality of pixel signals are added within one group such that spatial color array of each color becomes the same before and after addition, a problem is that a small amount of moiré can be observed under magnification.
As described above, with the conventional techniques, there are problems wherein improvement of sensitivity is insufficient due to thinning out of pixel signals, and also, moiré occurs even though the spatial color array is the same.

Imaging device for adding signals including same color component


The disclosed embodiments relate to forming an area on a touchscreen which electrically isolates a portion of the viewable area of the touchscreen from a capacitive sensor associated with the touchscreen.

A touchscreen is an electronic visual display that the user can control through simple or multi-touch gestures by touching the screen with one or more fingers. Some touchscreens can also be manipulated with other implements detect such as a stylus or ordinary or specially coated gloves. The user can use the touchscreen to react to what is displayed and to control how it is displayed (for example by zooming the text size). The touchscreen enables the user to interact directly with what is displayed, rather than using a mouse, touchpad, or any other intermediate device other than the optional stylus.
Touchscreens are common in devices such as game consoles, all-in-one computers, tablet computers, and smartphones. They can also be attached to computers or, as terminals, to networks. They also play a prominent role in the design of digital appliances such as personal digital assistants (PDAs), satellite navigation devices, mobile phones, and video games and some books. The popularity of smartphones, tablets, and many types of information appliances is driving the demand and acceptance of common touchscreens for portable and functional electronics. Touchscreens are found in the medical field and in heavy industry, as well as for automated teller machines (ATMs), and kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display's content.
A capacitive touchscreen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO). As the human body is also an electrical conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field, measurable as a change in capacitance. When a user touches the surface, the system records the change in the electrical current that flows through the display. Different technologies may be used to determine the location of the touch. The location is then sent to the controller for processing. The controller interprets the command that the touch represents and communicates the command to the appropriate application in the electronic device.


In a semiconductor device according to an embodiment, ends of conductor portions are electrically connected to an overvoltage protection diode so that depletion occurs in a diffusion layer in a portion near an insulating film in a reverse bias application state, and/or ends of conductor portions are electrically connected to the overvoltage protection diode so that depletion occurs in a peripheral semiconductor region in a portion near the insulating film in the reverse bias application state.

Semiconductor devices with a so-called MOS ("Metal-Oxide-Semiconductor") structure have conventionally been known. The semiconductor devices with the MOS structure (hereinafter referred to as "MOS-type semiconductor devices") include, for example, IGBTs ("Insulated Gate Bipolar Transistors") and MOSFETs ("MOS Field Effect Transistors").
Conventional MOS-type semiconductor devices include series-connected Zener diodes provided as overvoltage protection measures. Specifically, a Zener diode that is designed to break down at a voltage lower than the breakdown voltage of an MOS-type semiconductor device is disposed between the collector and the gate of the MOS-type semiconductor device (for example, see Patent Literature 1).
In order to ensure a breakdown voltage, the MOS-type semiconductor device has a voltage supporting region in a peripheral portion of a semiconductor substrate, and a conductor portion (which is called "field plate") is disposed along the voltage supporting region. The conductor portion is disposed on an insulating film located on the semiconductor substrate. This stabilizes the surface potential of the voltage supporting region to improve the reliability of the semiconductor device.

SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.


An object is to provide a floating bush bearing device including a circumferential groove over the entire circumference of an outer peripheral surface of a floating bush while ensuring that a pressing force is applied by lubricant oil to the floating bush to reduce oscillation, as well as a turbocharger provided with the bearing device. A floating bush bearing device includes: a rotary shaft disposed rotatably inside a bearing hole of a casing; a floating bush surrounding the rotary shaft; an oil-feed hole of lubricant oil having an opening on an inner peripheral surface of the bearing hole; a plurality of communication holes formed on the floating bush, each extending between an inner peripheral surface and an outer peripheral surface of the floating bush, and disposed at intervals in a circumferential direction of the floating bush; and a circumferential groove formed on the outer peripheral surface of the floating bush or the inner peripheral surface of the bearing hole and extending over an entire circumference of the outer peripheral surface of the floating bush or the inner peripheral surface of the bearing hole, the circumferential groove passing through openings of the plurality of communication holes or facing the openings of the plurality of communication holes. The circumferential groove has a cross-sectional area which varies in accordance with a circumferential position.

For instance, a turbocharger for an automobile includes a turbine and a compressor, and a turbine rotor of the turbine and an impeller of the compressor are coupled to each other via a rotor shaft. The rotor shaft is supported rotatably by a radial bearing, which supports loads in the radial direction.
For instance, Patent Document 1 discloses a radial bearing which is a floating bush bearing, and a floating bush bearing includes a floating bush fitted onto a rotor shaft via a gap. The floating bush is disposed in a bearing hole, and an oil path (oil-feed hole) has an opening on an inner peripheral surface of the bearing hole.
The floating bush includes a plurality of lubricant-oil communication holes penetrating through the floating bush diagonally with respect to the radial direction, and lubricant oil supplied in the bearing hole through the oil-feed hole flows inside the floating bush through the lubricant-oil communication holes of the floating bush. The central region of an outer peripheral surface of the floating bush having openings of the lubricant-oil communication holes is formed to have a concave surface, and the concave surface forms a circumferential groove of a constant width over the entire circumference of the outer peripheral surface of the floating bush.

Floating bush bearing device and turbocharger provided with the bearing device

MITSUBISHI HEAVY INDUSTRIES ENGINE & TURBOCHARGER, LTD.


A method and apparatus for performing data compression is disclosed that does not require interpolation of pixel data in order to define image blocks. More specifically, the present invention provides spatially interleaved image blocks composed of high frequency image components by sampling the high frequency image components at a pitch or spatial sample frequency equal to that of the low frequency image components. The present invention provides the added advantage of reducing the number of image blocks that must be defined in order to perform data compression.

The present invention is related to a method and apparatus for performing image compression. In particular, the invention eliminates the need for interpolation routines to define image blocks when performing image compression of a source image composed of highly sampled image components and less frequently sampled image components. The invention also reduces the number of image blocks required to perform image compression.
A common method of producing color image information in solid-state imaging systems is to provide a color filter array (CFA) over an image pixel plane of a solid-state imager. Generally, the CFA is configured to produce highly sampled image components (high frequency components) for luminance information and less frequently sampled image components (low frequency components) for color information. For example, the CFA may have a repeated pattern of several rows of green pixels followed by a single row of alternating red and blue pixels. In such a case, the higher frequency green pixels are used to provide luminance information while the lower frequency red/blue pixels are used to provide for color information. An example of such a CFA is illustrated in U.S. Pat. No. 4,876,590 issued to Parulski on Oct. 24, 1989.
The patterning of the CFA can cause difficulties when applying data compression techniques that utilizea discrete cosine transform to compress the image information generated in the above-described solid- state imaging systems. In order to perform data compression, the image information must be divided into a number of image blocks in which spatial samples in the image blocks are equally spaced, i.e., the total image information must be divided into a plurality of image blocks of equally spaced green pixels. The definition of the image blocks is typically accomplished by grouping adjacent green pixels. Interpolation routines must be performed, however, to replace the rows of lower frequency red/blue pixels with interpolated rows of green pixels prior to defining the image blocks and performing data compression, in order to maintain proper spacing between the green pixels.
The requirement for performing the interpolation routines adds complexity and expense to a data compression system. In addition, the speed at which data compression can be performed is reduced by the requirement for interpolating pixel data. Accordingly, it would be desirable to provide a method and apparatus for performing image compression that does not require the higher frequency image components to be interpolated prior to performing a data compression operation.

Method and apparatus for performing image compression using discrete cosine transform


A shut-off member provided on a rear end of an exhaust passage of the personal watercraft is formed to have such a shape that one of the ends of a short pipe made of nitrile rubber is flatly made, thereby including a lip portion having upper and lower side walls which come in contact with each other, and is protruded rearward and downward from a hull of the watercraft. A portion between the upper and lower side walls coming in contact with each other forms a slit to act as an exhaust port. The slit is substantially shut off based on a molding shape thereof if there is no difference between internal and external pressures of the shut-off member, and is opened against the elastic force of a surrounding flexible material depending on a differential pressure and a flow rate of an internal fluid if the internal pressure becomes higher than the external pressure.

1. Field of the Invention
The present invention relates to an exhaust outlet structure for a personal watercraft. More specifically, the present invention relates to an exhaust outlet structure for discharging the exhaust gas of an engine mounted on the personal watercraft.
2. Description of the Related Art
In general, the personal watercraft is provided with an exhaust outlet for discharging an exhaust gas from an engine at a rear portion of a hull. Some personal watercrafts serve to discharge cooling water of an engine and an exhaust system together with the exhaust gas from an exhaust outlet to a rear outside by a pressure (back pressure) of the exhaust gas. However, the personal watercraft is a vehicle to plane along the water surface. Therefore, the exhaust outlet is positioned on the water surface during running and is sometimes positioned below the water surface at the time of stop. Accordingly, if the exhaust outlet is kept open, there is a possibility that the water might flow from the outside to the inside through the exhaust outlet to cause a counterflow when the engine is stopped so as to prevent the discharge of any exhaust gas.
As shown in the prior art configuration of FIG. 8, conventionally, exhaust pipes 51 and 52 constituting exhaust passages in a personal watercraft S and a water muffler 53 for noise elimination have formed a maze. First of all, the water muffler 53 is divided into right and left chambers 53a and 53b by a bulkhead 54. A communicating pipe 55 for causing the chambers 53a and 53b to communicate with each other is provided slightly above the center of the bulkhead 54. The exhaust pipe 51 connected from an engine E to the water muffler 53 has a rear end 51a opened in the vicinity of a central portion of the front chamber 53a of the water muffler 53. The exhaust pipe 52 connected from the water muffler 53 to an exhaust outlet 56 provided in a rear portion of a hull of the watercraft S has a front end 52a opened in the vicinity of a central portion of the rear chamber 53b of the water muffler 53. Furthermore, the exhaust pipe 52 extends upward from the front end 52a thereof through the water muffler 53, and is then curved downward and extends rearward. Thus, a countermeasure has been taken such that the water stays in the bottom of the water muffler 53 so as not to cause a counterflow to the engine side even if it flows to the inside through the exhaust outlet 56 when the engine is stopped.
Since the cooling water is mixed in the exhaust gas to perform cooling of the exhaust gas, the water muffler 53 promotes a reduction in exhaust sounds. For this reason, a duplex pipe is usually used as the exhaust pipe 51 reaching the water muffler 53, and a portion between an outer pipe and inner pipe through which the exhaust gas passes, is formed as a passage for the cooling water. A rear end of the exhaust pipe 51 is opened in the water muffler 53, and the cooling water is mixed with the exhaust gas. The bulkhead 54 has a small communicating hole 58 such that the cooling water and the exhaust gas can flow into the chambers 53b from the chambers 53a.
When the watercraft S planes, a cavity V is generated on a water surface portion in a rear part of the watercraft S as shown in FIG. 8. Consequently, reflected sounds of the exhaust gas are made by a water surface F. In some cases, a nonreturn valve (also referred to as a bellows valve) 57 having a simple structure is provided on the exhaust outlet 56 for guiding an exhaust flow to the water surface as shown by an arrow A in order to control the reflected sounds.
In the drawing, the reference numeral 59 denotes a steering handlebar, the reference numeral 60 denotes a seat on which a driver sits, and the reference numeral 61 denotes a fuel tank.
Japanese Unexamined Utility Model Applications Nos. Hei 2-134000 and Hei 5-34100 have disclosed the exhaust outlet of the personal watercraft.
The water muffler 53 forms a part of the exhaust passage, and is greatly concerned with the performance of the engine. Accordingly, it is desirable that the exhaust passage provided in the water muffler 53 should have a shape which is as simple as possible in respect of an enhancement in the output performance of the engine and simplification of a performance test in the engine.
Although the nonreturn valve 57 has some effects of controlling the reflected sounds, sealing against the water on the outside is not sufficiently performed.

Exhaust outlet structure for personal watercraft