A nonaqueous-electrolyte secondary battery charging/discharging method that provides a prolonged cyclic life. In the charging/discharging method, a secondary battery is continuously charged unconditionally until a charging capacity exceeds 20% of a full charging capacity. The charging is completed when the charging capacity exceeds 70% of a full charging capacity. A maintenance charging/discharging operation is performed to avoid the full charging capacity being in an error state when dV/dt exceeds a specified value xe2x80x9caxe2x80x9d before a charging current exceeds 70% of the full charging capacity. Likewise, the maintenance charging/discharging operation is performed to avoid the full charging capacity being in an error state when dT/dt exceeds a specified value xe2x80x9cbxe2x80x9d before a charging current exceeds 70% of the charging capacity.

The present invention relates to a method for charging and discharging a nonaqueous electrolyte secondary battery. Particularly, the present invention relates to a method of charging and discharging a nonaqueous electrolyte secondary battery which provides excellent cyclic life characteristics.
Rechargeable secondary batteries, such as Nickel-cadmium (Nixe2x80x94Cd) batteries, nickel-hydrogen (Nixe2x80x94MH) batteries, and lithium-ion (Li-ion) batteries, are known batteries which are mounted on portable electronic equipment and which generate power driving the equipment. Such secondary batteries deteriorate through repeated charging and discharging and reduce the battery capacity thereof. These batteries have a cyclic life in which the battery capacity is substantially lost through repeated uses for a long period of time. For example, in Nixe2x80x94MH batteries, repeated charging and discharging (or charging/discharging cycle) causes erosion or deterioration of the negative electrode or positive electrode, thus producing non-uniformity of the electrolysis solution. This results in a cyclic life in which only the charging capacity of substantially a half of the initial full charging capacity of a battery cell can be obtained.
Such a cyclic life can be predicted when examination is made, for example, by limiting the temperature and current in charging/discharging to predetermined conditions. However, because actual batteries are used in various situations, the charging/discharging cycles described on product catalogs cannot be applied to all batteries. Particularly, over-charging or over-discharging often causes a shortage in the cyclic life of the battery. For that reason, in the design and development of the secondary batteries, the problem is to fabricate batteries that adapt to working conditions and environments and that have sufficient cyclic operational life.
By the way, the secondary batteries having the above-mentioned cyclic life are used for electronic equipment, including information equipment (such as digital cameras, personal computers, and the like) and communications equipment (such as personal telephones). However, the time period for which the equipment can be used through one-time charging is shortened with degradation of the battery capacity.
When the battery reaches the end of its cyclic life, the electronic equipment itself does not work substantially. In such a case, the user cannot simply determine whether the equipment is in failure or the battery is dead or the battery has reached the end of its cyclic life. In such a situation, it is necessary to detect the cyclic life of the secondary battery on the side of the electronic measuring equipment and tell the user the detected information.
There a method of predicting a battery capacity by measuring the internal resistance inherent in a battery and by detecting the rate of increase with the charging/discharging cycles or by integrating the capacity until the battery becomes an empty state through discharging from a full charging state.
However, the internal resistance measuring method requires a high-precision measuring device. Moreover, in the method of integrating changes in battery capacity due to discharging, because the voltage across a detection resistor through which the current flows is amplified and detected, power is wasted. Moreover, this method requires a high-precision amplifier.
It may be considered that the count value of charging/discharging cycles is stored in a memory disposed in the battery. However, such a memory leads to increasing the fabrication costs. Moreover, the problem is that some use conditions of a battery result in the charging/discharging count of an initial promised cyclic life not matching with the actual charging/discharging count.
In recent years, nonaqueous electrolyte secondary batteries have been made of an alkali metal such as lithium acting as the negative electrode active substance, and an electrolysis solution in which LiClO4, LiBF4, iAsF6, LiPF6, or LiCF3SO3 is dissolved in an organic solvent. The organic solvent is, for example, propylene carbonate, xcex3-butyrolactone, dimethoxyethane, tetrahydrafuran, or dioxane. These nonaqueous electrolyte batteries, having a high energy density, have been broadly used for small-size electronic devices such as electronic watches, cameras, and others. One of problems in making it possible to charge a nonaqueous electrolyte battery of that type is suppressing an arboreous, fibrillar, or acerate alkaline metal separated out on the negative electrode in the course of charging process; that is, the so-called dendrite. When the dendrite grows excessively, the operational life of the battery may be instantaneously terminated because of an internal shorted-circuit between the negative electrode and the positive electrode. Even if it is tried to dissolve the dendrite in the course of the post-discharging, the dendrite is locally dissolved and part thereof is electrically alienated from the polar plate. For that reason, all dendrites cannot be dissolved. That is, this phenomenon decreases a discharging (dissolution) amount to a charging (precipitation) amount, thus deteriorating the charging/discharging efficiency.
Two methods have been conventionally proposed to suppress the formation of dendrite in the course of the charging/discharging. In one method charging is carried out under such moderate conditions that the negative electrode potential is maintained at more than xe2x88x9250 mVvs.Li+/Li and that the alkali metal (lithium) to be educed is maintained at 0.3 mAh/cm2. In the other method, the charging/discharging efficiency is simultaneously improved by combining the electrolysis solution and a solvent of a high dielectric constant and of a low viscosity. These approaches are based on the idea of uniformly a separation reaction of the alkali metal on the electrode surface and thus suppressing the separation of dendrite.
However, even if the above-mentioned methods are employed, it is still difficult to fabricate a nonaqueous electrolyte secondary battery which has a cyclic life of 500 cycles or more, practically required as a secondary battery, while a high energy density is maintained. This difficulty comes from the fact that minute heterogeneous reactions repeated with charging/discharging cycles and integration of dendrite lead to changes to the heterogeneous reaction on electrodes. The minute uniformity results from the formation of a passive film through the reaction between an alkali metal acting as an active substance and an electrolysis solution or from differences in internal pressure applied to the respective electrodes in the winding-type battery. Moreover, the unevenness is triggered by the formation of dendrite and a decrease in charging/discharging efficiency.
In secondary batteries, a high voltage caused in charging may induce a dangerous state such as smoking or burning. In such a case, an irreversible chemical reaction may occur inside the battery, thus remarkably reducing the battery performance. Moreover, a low voltage caused in discharging may also induce an irreversible chemical reaction inside a battery, thus remarkably reducing the battery performance. For secondary batteries, manufacturers specify the upper limit voltage and the lower limit voltage, to be obeyed by users, to maintain batteries in safe state and to suppress drastic decreases in the performance thereof.
Generally, a secondary battery has a tendency of both the chargeable capacity and the dischargeable capacity decreasing as charging and discharging are repeated. The capacity decrease is called cyclic deterioration, or merely, deterioration. This is a matter of the operational life of a battery. There are several kinds of definitions of the chargeable/dischargeable capacity of a secondary battery. Typically, the chargeable/dischargeable capacity is defined as the product of an output power or output current when a battery charged to the upper voltage has been discharged to the lower voltage, multiplied by a discharging time period.
One reason for deterioration of a battery is that the battery is charged to the upper limit voltage and then discharged to the lower limit voltage, or that the chargeable/dischargeable capacity are used in its full range. This results from the fact that heat generation or electrolysis at the termination of charging or discharging causes deformation of the structure of a battery or changes in a substance""s properties, thus resulting in deterioration of the battery.
The capacity of a brand-new battery, that is, the capacity in small charging/discharging cycles after product shipment, or in the time when a battery has operated only for a short period of time, is defined as 100%. According to types or uses of batteries, the time period when the capacity becomes 70% or 80% is defined as the life of a battery. The charging/discharging repeated to the operational life is called a cyclic life.
When a battery is charged to the upper limit or discharged to the lower limit, the initial capacity is large but the battery quickly deteriorates, as shown in the curve xe2x80x9caxe2x80x9d in FIG. 4. On the other hand, when the battery is charged below the upper limit and discharged above the lower limit, the initial capacity becomes small but the battery gradually deteriorates, as shown in the curve xe2x80x9cbxe2x80x9d in FIG. 4. However, the cyclic life is not much extended.
In order to deal with such problems, the technique disclosed in JP-P1997-120843A was proposed. According to this technique, when a secondary battery is new, the charging voltage is set to a value lower than the set upper limit or the discharging voltage is set to a value higher than the set lower limit, or both are carried out. As the chargeable/dischargeable capacity decreases, the charging voltage is set to a value close to the upper limit or the discharging voltage is set to a value close to the lower limit or both are carried out. Thus, suppressing a decrease in chargeable/dischargeable capacity of a secondary battery prolongs the operational life.
The conventional technique will be explained below as a first prior art by referring to the attached drawings.
FIG. 5 is a block diagram of the first prior art and FIG. 6 is a flowchart of the first prior art.
As shown in FIG. 5, the secondary battery 55 is connected to the controller 54 in the charging/discharging controller 51. The secondary battery 55 is a lithium-ion secondary battery. In the lithium-ion secondary battery, the positive active substance is LiCoO2; the negative active substance is a carbon; and the nonaqueous electrolyte (electrolysis solution) is an electrolysis solution.
A power source 57, which supplies a dc voltage and a dc current, is connected to the controller 54. A load 56, which consumes power, corresponds to, for example, an electric valve, an iron, a motor, a computer, or a radio set. The load 56 is connected to the controller 54.
The charging/discharging controller 51 consists of a capacity decider 52, a charging/discharging voltage setter 53, and a controller 54. The capacity decider 52 is formed of a count setter 520 and a counter 521. The count setter 520 is formed of, for example, a digital switch. When the secondary battery 55 is replaced by another battery, the count setter 520 sets the charging/discharging cycles counted till that time. The charging/discharging count set by the count setter 520 is set in the counter 521. The counter 521 is, for example, a digital counter.
The counter 521 transmits the charging/discharging count based on digital signals, to the numerical converter 59 in the charging/discharging voltage setter 53.
The numerical converter 59 sets the upper limit charging voltage value Vh and the lower limit discharging voltage value Vl set to the charging count (cycle), as shown in FIG. 7. For example, when the charging cycle is 0 to 499, the upper limit charging voltage value Vh is set to 4.0 volts and the lower limit discharging voltage value is set to 3.0 volts. When the charging cycle is 500 to 999, the upper limit charging voltage value Vh is set to 4.05 volts and the lower limit discharging voltage value Vl is set to 2.9 volts. When the charging cycle is 1000 to 1499, the upper limit charging voltage value Vh is set to 4.1 volts and the lower limit discharging voltage value Vl is set to 2.8 volts. When the charging cycle is 1500 to 1999, the upper limit charging voltage value Vh is set to 4.15 volts and the lower limit discharging voltage value Vl is set to 2.7 volts. When the charging cycle is 2000 or more, the upper limit charging voltage value Vh is set to 4.2 volts and the lower limit discharging voltage value Vl is set to 2.5 volts.
In the charging/discharging voltage setter 53, the D/A converter 510 converts the upper limit charging voltage value set in the numerical converter 59 into an actual set voltage. The D/A converter 511 converts the lower limit discharging voltage value set in the numerical converter 59 into an actual set voltage.
The D/A converter 510 transmits the upper-limit charging voltage value Vh to the comparator 512 in the controller 54. The D/A converter 511 transmits the lower-limit discharging voltage value Vl to the comparator 513 in the controller 54. The controller 54 is formed of the comparators 512 and 513, the charging/discharging commander 514, and the switches 515 and 516.
The comparator 512 compares the upper-limit charging voltage value Vh from the D/A converter 510 with the voltage value Vb of the secondary battery 55 and then transmits the result to the charging/discharging commander 514. The comparator 513 compares the lower-limit discharging voltage value Vl from the D/A comparator 511 with the voltage value Vb of the secondary battery 55 and then transmits the result to the charging/discharging commander 514. Each of the comparators 512 and 513 is formed of, for example, a voltage comparator.
The charging/discharging commander 514 is formed of, for example, logic circuits. While watching signals from the comparators 512 and 513, the charging/discharging commander 514 ceases the charging operation when Vbxe2x89xa7Vh, thus allowing the discharging operation. When Vh  greater than Vb greater than Vl, the charging/discharging commander 514 continues the previous state. When Vbxe2x89xa6Vl, the charging/discharging commander 514 ceases the discharging operation, thus allowing the charging operation.
The charging/discharging commander 514 transmits a charging signal to the counter 521. The counter 521 adds occurrences of the charging signals.
When a charge allowance is issued, the switch 515 connects the power source 57 to the secondary battery 55 according to the charging signal from the charging/discharging commander 514. When a charge allowance is not issued, the switch 515 does not connect the power source 57 to the secondary battery 55. When a discharge allowance is issued, the switch 516 connects the load 56 to the secondary battery 55 according to the charging signal from the charging/discharging commander 514. When a discharge allowance is not issued, the switch 516 does not connect the load 56 to the secondary battery 55. Each of the switches 515 and 516 is formed of, for example, an electromagnetic relay or a semiconductor switch.
In the above-mentioned configuration, cyclic operation is repeated by charging the secondary battery 55 up to the upper-limit charging voltage value Vh by means of the power source 57 and discharging the secondary battery 55 up to the lower-limit discharging voltage value Vl by means of the load 56.
The operation of the above-mentioned example will be explained here by referring to FIG. 6.
First, when the secondary battery 55 is connected to the charging/discharging controller 51, the charging/discharging count, that is, the chargeable/dischargeable capacity decision value of the secondary battery 55, is set in the count setter 520 in the capacity decider 52 (step S1).
Next, in the step S2, the capacity decider 52 decides the chargeable/dischargeable capacity by means of the signals from the controller 54 (step S2).
Next, the charging/discharging voltage setter 53 changes the upper-limit charging voltage Vh and the lower-limit discharging voltage Vl, in accordance with the chargeable/dischargeable capacity decision value, that is, in accordance with the charging/discharging count (cycles) (step S3).
Next, the comparator 512 compares the upper-limit charging voltage Vh with the battery voltage Vb. The comparator 513 compares the lower-limit discharging voltage Vl with the battery voltage Vb. In the comparison, when Vbxe2x89xa7Vh, the charging/discharging commander 514. prohibits charging but allows discharging, in the step S5B. When Vh greater than Vb greater than Vl and charging is in an allowance state, the charging/discharging commander 514 allows charging but prohibits discharging in the step S5A. When Vh greater than Vb greater than Vl and discharging is in an allowance state, the charging/discharging commander 514 prohibits charging but allows discharging in the step S5B (steps S4A and S4B).
When Vbxe2x89xa6Vl, the charging/discharging commander 514 allows charging but prohibits discharging in the step S5A. The charging/discharging commander 514 measures the chargeable/dischargeable capacity in the step S2.
The charging/discharging commander 514 allows charging but prohibits discharging in the step S5A. Thus, the switch 516 opens to disconnect the secondary battery 55 from the load 56 while the switch 515 closes to connect the power source 57 with the secondary battery 55 (step S6A).
In the step S5B, the charging/discharging commander 514 prohibits charging but allows discharging. Thus, the switch 515 opens to disconnect the power source 57 from the secondary battery 55 while the switch 516 closes to connect the secondary battery 55 with the load 56 (step S6B).
Next, the flow goes back to the steps S4A and S4B and the operation is repeated.
It is now assumed that the dischargeable capacity of a new secondary battery immediately after manufacture, with the upper-limit voltage of 4.2 volts and with the lower-limit voltage of 2.5 volts, is defined as 100%. It is assumed that the discharging capacity, with the initial upper-limit charging voltage set to 4.0 volts and the lower-limit discharging voltage set to 3.0 volts, is defined as 80% of the dischargeable capacity. In such a case, when the discharging capacity drops to 70% through repeated charging/discharging, the upper-limit charging voltage is set to 4.05 volts and the lower-limit discharging voltage is set to 2.9 volts. This control allows the discharging capacity to be restored up to 80%. Moreover, every time when the discharging capacity decreases to 70% through the repeated charging/discharging operation, the upper-limit charging voltage is charged from 4.10 volts to 4.15 volts while the lower-limit discharging voltage is charged from 2.8 volts to 2.7 volts. Finally, the secondary battery is used until the discharging capacity decreases to 70%, with the upper-limit charging voltage of 4.20 volts and with the lower-limit discharging capacity of 2.5 volts. In the charging/discharging method, a change in charging/discharging capacity is shown with the curve xe2x80x9ccxe2x80x9d shown in FIG. 4. The corresponding charging/discharging capacity is shown with the curve xe2x80x9cdxe2x80x9d shown in FIG. 4.
The above-described operation suppresses a decrease of the chargeable/dischargeable capacity of the secondary battery 55.
However, because the initial charging capacity of a battery is set as a full charging capacity, the prior art system tries to charge up to 80% of the initial charging capacity, regardless of deterioration of the battery caused by repeated charging/discharging. For that reason, there is the problem in that charging the deteriorated battery over its charging capacity accelerates further deterioration of the deteriorated battery under some conditions.
JP-P2000-23388A discloses the same kind of technology. In this technology, the charging constant voltage is set to a low value. As the charging cycle advances, the charging voltage gradually increases. Thus, deterioration of the electrodes can be suppressed while an adverse effect caused by deterioration due to temperature can be compensated. As a result, the charging/discharging cyclic life of the secondary battery can be prolonged.
JP-P2000-30750A discloses two methods for charging a nonaqueous secondary battery having excellent cyclic life characteristics. In one charging method, a nonaqueous secondary battery includes a chargeable/dischargeable positive electrode, an electrolysis solution, and a chargeable/dischargeable negative electrode. After the secondary battery begins its charging, the charging is ceased before the closed circuit voltage of the secondary battery reaches the decomposition voltage of the electrolysis solution. In the other charging method, after the secondary battery begins its charging, the charging is ceased before the capacity charged therein reaches the rated capacity thereof.
JP-P1998-255854A discloses a method of charging and discharging a nonaqueous electrolyte secondary battery which maintains the uniform electrode reaction and prolongs the charging/discharging cycle life. This method discloses the technique of repeating the charging/discharging cycle to increase the discharging electric amount more than the charging electric amount and then fully charging the battery when the discharging capacity becomes a constant value or less.
Next, a second prior art will be explained below.
FIG. 8 is a block diagram illustrating the second conventional technique. FIG. 9 is a graph plotting capacity maintenance ratios and constant-current charging capacity ratios of a lithium-ion secondary battery versus changes of charging/discharging cycles. FIG. 10 is a characteristic diagram illustrating charging voltage curves of a lithium-ion secondary battery. FIG. 11 is a characteristic diagram illustrating a charging voltage curve of a nickel-cadmium secondary battery and a charging voltage curve of a nickel-hydrogen secondary battery.
In the secondary battery capacity deterioration decider, as shown in FIG. 8, the charger is connected to the secondary battery 312 such as a lithium-ion battery, a nickel-cadmium battery or a nickel-hydrogen battery. The identification element 320 detects the type of the secondary battery 312.
The controller 318 starts a constant current charging process in accordance with the battery voltage of the secondary battery 312. When the battery voltage reaches a reference voltage value according to the type of the secondary battery 312 during the charging process, the timer disposed in the controller 318 starts measuring the constant current charging time period. When the changeover to the constant voltage charging, or xe2x88x92xcex94V, is detected through the charging control system in accordance with the battery type, the time measuring operation ends. xe2x88x92xcex94V means a small drop of a battery voltage which occurs while a battery is being charged in spite of being in a full charged state.
The controller 318 compares the measured constant current charging time with the constant current charging time at the initial stage of the battery. Based on the comparison result, the controller 318 decides the degree of cyclic degradation of the battery charge capacity of the battery in accordance with the battery type. The notifier 326 notifies the user of the decision result.
Next, the charging/discharging cycle of a chargeable/dischargeable lithium-ion secondary battery will be explained by referring to FIG. 10.
In FIG. 10, the curve 40a represents a charge voltage curve corresponding to one charge/discharge cycle. The curve 40b represents a charge voltage curve corresponding to 100 charge/discharge cycles. The curve 40c represents a charge voltage curve corresponding to 200 charge/discharge cycles.
As shown in FIG. 10, the constant current charge (CC) time period which is taken from the voltage at a charge starting time or from a predetermined voltage VP1 during constant current charging to the constant voltage charging (CV) is shortened with an increasing number of battery charging/discharging cycles. The constant current charge (CC) time 42 in the curve 40c is shorter than the constant current charge (CC) time 44 in the curve 40a. When the constant current charging is completed, the lithium-ion secondary battery is shifted to the region of the constant voltage charging (CV) and thus charged. It is decided whether or not the battery is in a fully charged state during the constant voltage charging. Thus, when the lithium-ion secondary battery is in a fully charged state, the charging operation is completed.
As the charging/discharging cycle becomes large through repeated charging/discharging, the constant current charging time is shortened so that the battery capacity is reduced.
FIG. 11 shows charging voltage curves in the case where a nickel-cadmium (Nixe2x80x94Cd) secondary battery or a nickel-hydrogen (Nixe2x80x94MH) secondary battery is subjected to constant current charging and the charging operation is stopped by means of the xe2x88x92xcex94V detection method. According to the xe2x88x92xcex94V detection method, as a secondary battery such as a nickel-cadmium battery is charged with a constant current, the terminal voltage thereof increases. When the maximum value of the terminal voltage is detected, the terminal voltage decreases by a small value from the maximum value thereof. Thus, the charging control such as full charging process is carried out.
As shown in FIG. 11, after repeated cycles of charging/discharging, the CC time 52 of the curve 50b, corresponding to 200 charging cycles, is shorter than the CC time 54 of the curve 50a corresponding to one charging cycle. Here, the CC time corresponds to the time period between a charge starting time, or the time when the predetermined voltage VP2 appears during the constant current charging (CC), and the time when a small drop (xe2x88x92xcex94V) of the terminal voltage is detected.
In FIG. 9, the curve 30 shows how the capacity maintenance ratio of a lithium-ion secondary battery decreases through repeated charging/discharging cycles. The cyclic life means the cycle number or the state of a battery at the time when the capacity maintenance ratio is 50% to 60%. The capacity maintenance ratio shows a ratio of a current full charging capacity of a battery to an initial full battery charging capacity thereof. The capacity maintenance ratio of a battery at the start of use is defined as 100%. When the charging/discharging cycle is repeated, the battery becomes a full charging state where the charging is saturated, so that the capacity maintenance ratio decreases. When the charging/discharging is further repeated, the capacity maintenance ratio becomes 50% to 60%. Thus, it is determined that the battery has reached its cyclic life.
Referring to FIG. 9, the curve 32A shows the charging/discharging cycle of a secondary battery A. The curve 32B shows the charging/discharging cycle of a secondary battery B. The curve 32C shows the charging/discharging cycle of a secondary battery C. The secondary batteries A, B and C are lithium ion batteries, but are produced by different manufacturers and have different performances. The constant current charging capacity ratio is a ratio of a battery capacity of a brand-new battery to be initially charged through constant current charging to a battery capacity of a battery in current use to be charged through constant current charging. This constant current charging capacity ratio corresponds to a constant current charging time period charged with constant current.
By referring to FIG. 9, there is seen a correlation between the capacity maintenance rate and the constant current charging (CC) capacity rate (ratio), although there is somewhat a difference between the battery types A, B and C. The constant current charging time is shortened as the constant current charging (CC) capacity decreases with cyclic deterioration. The capacity maintenance rate of a secondary battery can be determined. Thus, it can be checked whether or not the battery has reached its cyclic life.
However, the second prior art has a problem in that when charging/discharging is repeated, the integrated capacity errors are accumulated, so that whether or not the battery operational life has reached cannot be accurately determined.
The present invention is made to solve the above-mentioned problems. An object of the present invention is to provide an improved method for charging and discharging a nonaqueous electrolyte secondary battery, whereby a prolonged cyclic life is obtained.
In an aspect of the present invention, an apparatus for charging and discharging a nonaqueous electrolyte secondary battery comprises a first switch for connecting or disconnecting a secondary battery and a charging power source; a second switch for connecting or disconnecting the secondary battery and a load; a full charging capacity memory for storing a full charging capacity value of the secondary battery; means for detecting a charging capacity of the secondary battery during charging, for connecting the secondary battery and the charging power source by controlling the first switch when the detected charging capacity is less than a first predetermined ratio of the full charging capacity, and for disconnecting the secondary battery and the charging power source by controlling the second switch when the detected charging capacity is a second predetermined ratio or more of the fill charging capacity; means for calculating a voltage variation dV/dt of the secondary battery during charging; means for calculating a temperature variation dT/dt of the secondary battery during charging; means for deciding whether or not each of the voltage variation dV/dt and the temperature variation dT/dt exceeds a specified value, detecting whether or not the secondary battery is in a full charging state during charging based on the voltage and the temperature of the secondary battery during charging when at least one of the voltage variation dV/dt and the temperature variation dT/dt exceeds a specified value, and controlling the second switch when the secondary battery is in a fill charging state, thus connecting the secondary battery and the load to discharge the secondary battery; and means for detecting completion of discharging of the secondary battery, computing a full charging capacity based on a discharging current when discharging is completed, and updating a full charging capacity stored in the full charging capacity memory.
In the apparatus, the secondary battery comprises a nickel-hydrogen battery.
Another aspect of the present invention, a method for charging and discharging a nonaqueous electrolyte secondary battery comprises calculating a voltage variation dV/dt of the secondary battery during charging; calculating a temperature variation dT/dt of the secondary battery during charging; detecting a charging capacity of the secondary battery during charging and then, when the charging capacity detected is less than a predetermined ratio of a stored full charging capacity, deciding whether or not at least one of a detected voltage variation dV/dt and a detected temperature variation dT/dt exceeds a previously specified value; when at least one of the detected voltage variation dV/dt and the detected temperature variation dT/dt exceeds the previously specified value, detecting whether or not the secondary battery during charging is in a full charging state based on the voltage and the temperature of the secondary battery during charging; discharging the secondary battery when a full charging state is detected; detecting completion of discharging of the secondary battery, computing, upon completion of charging, a full charging capacity based on a discharging current of the secondary battery, and updating the stored full charging capacity; and completing charging of the secondary battery when the stored charging capacity is a predetermined ratio or more of a stored full charging capacity.
The method further comprises the step of charging the secondary battery unconditionally in initial charging thereof until a current charging capacity reaches 20% of the full charging capacity.
In another aspect of the present invention, a method for charging and discharging a nonaqueous electrolyte secondary battery comprises recharging a battery to less than a full charging amount of the battery; and supplying a recharging amount to a load.
In the method, the recharging amount is set to 70% of the full charging amount.
The method further comprises the step of continuously charging the battery unconditionally in initial charging thereof until a current charging capacity reaches 20% of a reference charging amount.
In the method of the present invention, said battery comprises a nickel-hydrogen battery.
In another aspect of the present invention, a method for charging and discharging a nonaqueous electrolyte secondary battery comprises continuously charging the secondary battery unconditionally until the charging capacity exceeds 20% of a full charging capacity because the temperature and the voltage of the battery become unstable in initial charging; ending the charging operation when the charging capacity exceeds 70% of the full charging capacity; performing a maintenance charging/discharging operation because there is the possibility of an erroneous full charging capacity when dV/dt exceeds a specific value xe2x80x9caxe2x80x9d before the charging capacity exceeds 70% of the full charging capacity; and performing the maintenance charging/discharging operation because there is the possibility of an erroneous full charging capacity when dT/dt exceeds a specific value xe2x80x9cbxe2x80x9d before the charging capacity exceeds 70% of the full charging capacity.
The method further comprises by means of a controller, acquiring a voltage of the battery from a voltage measuring section and a temperature of the battery from a temperature measuring section and thus detecting full charging (S22); when a full charging is detected, turning on a switch and supplying power from the battery to a load (S24); simultaneously acquiring a discharging current from a charge/discharge current measuring section and integrating a discharging capacity (S25); and simultaneously acquiring a battery voltage of the battery from a voltage measuring section, ending discharging (S27) and capacity integration (S28) by turning off the switch when the battery voltage becomes empty, and updating the full charging capacity (S29).

Method for charging and discharging battery based on charging capacity


In a course of updating old map data on a hard disk drive to new map data, a low-priority portion of the old map data that has less importance/necessity is deleted to create a vacant area, and a high-priority portion of the new map data is copied to the vacant area as an update of the map data. Then, the high-priority portion of the old map data is deleted to create another vacant area, and a low-priority portion of the new map data is copied to the vacant area. During the update of the map data, restrictions on the usage of the map data are avoided at all efforts by having the high-priority portion of at least one of the new map data and the old map data maintained on the hard disk drive, while maximizing the utilization of storage resources in a map data management apparatus.

Conventionally, the navigation apparatus used in a vehicle utilizes map data retrieved from a storage unit and a current position of the vehicle derived from GPS unit for displaying the current position on a map on a display unit and for guiding a driver of the vehicle toward a destination together with other assistance.
The navigation apparatus retrieves the map data, by using a reader device such as a CD-ROM drive, a DVD-ROM drive or the like, from a storage medium of CD disks, DVD disks or the like. Alternatively, the map data may be stored in a hard disk drive (HDD).
The map data to be used for route guidance or other function is required to be updated in order to catch up the recent change of the map. The map data may be updated by just replacing the storage medium (e.g., CD-ROM) with the one having the latest data. That is, the map data update is complete when the data storage medium is replaced.
On the other hand, the map data stored on the HDD is required to be replaced with new data. Japanese Patent Document JP-A-H11-95657 discloses the map data update method of that kind.
However, the update of the map data stored on the HDD may take time due to the data volume of the map data or the like. That is, the map data used in the navigation apparatus includes various data types such as road network data for representing connection conditions of the roads, map matching data for the accuracy of positioning, facility data for representing facility information, voice data for providing voice guidance and the like.
Further, during the update of the map data, the operation of the navigation apparatus may be restricted or stopped. For example, if the old map data is completely deleted from a map data storage area for creating vacancy that accommodates the new map data, the map data can not be utilized until the completion of the storage of the new map data.
On the other hand, if the old map data is left in the storage until the completion of the storage of the new map data and the deletion of the old map data take place after the completion of the storage of the new map data, that is, if the old map data and the new map data are made to be co-existing on the same HDD, the map data storage area needs to have a greater capacity for storing both of the new and old map data.

Apparatus and method for map data management


The present invention relates to a device and a process for estimating the noise level of video images before coding. The device comprises in particular means of storage of at least one input image, a blockwise motion estimation module, designed to produce, blockwise, first quantities representative of motion-compensated image variations, on the basis of a current input image and of at least one input image stored previously in the said means of storage, means of estimation of a global noise level for each image as a function of at least certain of the said quantities representative of motion-compensated image variations, The said device comprises means of estimation of a local noise level for each block of the image as a function of second quantities representative of motion-compensated image variations and of the global noise level.

It relates to noise level estimation techniques applied to digital video signals. These techniques for estimating noise level are used in noise reduction techniques. Noise reduction techniques are generally applied to digital video images taking the form of a matrix of samples; each sample is composed of a luminance signal and, for a colour signal, of a chrominance signal.
The acquisiton of video image sequences is today still widely carried out in analogue form so that the images, once acquired and possibly forwarded and stored in analogue formats, exhibit an appreciable share of noise in their content. Once digitized, these images are also often subjected to storage/editing operations which, in their turn, introduce noise of a digital nature, this time. Finally, an image sequence generally undergoes a succession of transformations resulting in spatio-temporal noise of a strongly random nature.
To obtain high-performance functioning, noise reduction methods calling upon recursive filtering consider the very strong temporal correlation of the images of a video sequence. Consequently, the concepts of motion and of displacement are important in the fine-tuning of effective noise reduction.
The term <<displacement>> is understood to mean the change in position of an object in a scene, this change in position being localized and specific to this object. The term <<motion>> is understood to mean the entire set of displacements of objects in a video sequence.
Motion is conventionally detected either by simple image-to-image differencing, or by using a motion estimator.
When a motion estimator is used, the displacements are taken into account by computing image differences at distinct instants as well as by moving spatially within the frames. These displacements are represented by motion vector fields applied to pixels (pixelwise motion estimation) or to blocks (blockwise motion estimation). Motion-compensated image differences, called DFDs (Displacement Frame Differences), are thus obtained pixelwise or blockwise.
In known systems, the estimation of the noise level is done at the level of the image frames. This estimation leads to the noise being made uniform over the frame, and consequently the filtering also, this possibly giving rise to certain defects such as loss of definition over certain noise-free zones, the appearance of blur or the smoothing of certain textures (lawns for example). Such systems are for example described in French Patent Application 009684 filed on 24 Jul. 2000 in the name of the Thomson Multimédia Company.

Device and process for estimating noise level, noise reduction system and coding system comprising such a device


Disclosed are methods, apparatus and systems for a binary neural network accelerator engine. One example circuit is designed to perform a multiply-and-accumulate (MAC) operation using logic circuits that include a first set of exclusive nor (XNOR) gates to generate a product vector based on a bit-wise XNOR operation two vectors. The result is folded and operated on by another set of logic circuits that provide an output for a series of adder circuits. The MAC circuit can be implemented as part of binary neural network at a small footprint to effect power and cost savings.

Neural networks are currently the foundation for many modern artificial intelligence (AI) applications. The superior performance of neural networks comes from their ability to extract high-level features from raw sensory data after using statistical learning over a large amount of data to obtain an effective representation of an input space. Implementations of neural networks find applications in a myriad of applications from self-driving cars, to detecting cancer, and to playing complex games.
The complexity of neural networks, from both a memory and power consumption standpoint, can be reduced by using reduced precision activations and weights in the neural network. Binary neural networks (BNNs) replace some of the floating or fixed-point arithmetic in traditional convolutional neural networks with significantly more efficient bitwise operations, and with a minimal loss of accuracy.
Computational savings effected by the BNNs make them suitable for implementation in Internet of Things (IoT) applications. IoT is a network of physical devices that can include appliances, vehicles and other devices that have embedded electronics, software, and network connectivity to enable these physical devices to connect and exchange data. Each physical device of the IoT can be uniquely identifiable through its embedded computing system and is able to communicate with other devices using the existing infrastructure of the Internet. While not limited to IOT, the small form factor, ultra-low power consumption, and low cost requirements make power consumption and physical footprint of the associated circuitry critically important in IoT applications since they directly impact the battery lifetime, cost and efficiency of such systems.

Binary neural network accelerator engine methods and systems


A broadband omni-directional bicone antenna. The antenna can comprise conductive surfaces of conical voids provided within a solid dielectric structure. The outside surface of the solid structure can support a radio frequency (RF) lens geometry operable for beam forming. The beam forming can modify the elevation pattern of the electromagnetic radiation from the bicone antenna. The solid dielectric structure may be machined or molded from a single piece of material. The conical voids provided within the solid structure can be metallized to provide conductive bicone radiators. The outer surface beam shaping lenses can be zoned or continuous and can provide elevation patterns with increased gain, cosecant squared falloff, or various other patterns. The beam shaping lens may be formed from any low-loss dielectric. Alternatively, the lens may be formed from a less dense material such as dielectric foam that can support radial conductive beam forming vanes.

A bicone is generally an antenna having two conical conductors, where the conical elements share a common axis, and a common vertex. The conical conductors extend in opposite directions. That is, the two flat portions of the cones face outward from one another. The flat portion of the cone can also be thought of as the base of the cone or the opening of the cone. The flat portion, or opening, of a cone is at the opposite end of the cone from the vertex or point of the cone. Bicone antennas are also called biconical antennas. Generally, a bicone antenna is fed from the common vertex. That is, the driving signal is applied to the antenna by a feed line connected at the antenna's central vertex area.
Positioning two cones so that the points (or vertices) of the two cones meet and the openings (or bases) of the two cones extend outward (opposite one another) results in a bowtie-like appearance. As such, some bicone antennas are called bowtie antennas.
Bicone antennas are generally omni-directional and thus may have low gain. The elevation pattern of a bicone can be directed or shaped using a lens. Such a lens is generally an additional external element that must be positioned within the field of the antenna in order to influence the radiation patterns of the bicone. These external elements may involve additional handling, manufacturing, cost, and complication. They may also reduce mechanical robustness of an antenna assembly. Furthermore, external lens elements may not be available for all bicone systems and may not fulfill specific elevation shaping requirements.
Accordingly, there is a need in the art for a broadband omni-directional bicone antenna with an integrated beam shaping lens where the bicone structure and lens can be machined or molded from a single piece of material.


One or more burst disks, for isolating downhole communication between a tubular and a hydrocarbon-bearing formation, are fit with a shaped explosive charge. Detonation of the shaped charge is initiated by the rupture of the burst disk. In a system for stimulating the formation, one or more sets of two or more shaped charge, enhanced burst disks are located at a location along the tubular corresponding to a selected interval for stimulation. The enhanced burst disks can be fit with a chamber of known pressure for establishing a known and significant pressure differential across the burst disk for enabling substantially simultaneous rupture at the selected interval.

In the recovery of oil and gas from subterranean hydrocarbon formations, it is common practice to stimulate or fracture the hydrocarbon-bearing rock formation, providing or enhancing flow channels for oil and gas. These flow channels facilitate movement of the hydrocarbons into the wellbore so they may be produced from the wellbore. Without fracturing, many wells would not be economically viable.
In such fracturing operations, a fracturing fluid is injected down a wellbore penetrating the hydrocarbon formation. The fracturing fluid is forced down an annulus of the wellbore and into the formation strata or rock under pressure, forcing the rock to crack apart. Various methodologies are known for stimulating formations in horizontal or vertical open hole completion. One such methodology is a Source MultiStim™ system employing a multi-stage cased/open hole hybrid system that sets up wellbore isolation and frac points along an open hole section of the wellbore. A MultiStim™ frac liner and packers are run into an open hole for isolating a series of zones. Each zone can be stimulated in sequence accessed through a series of open/close sleeves in the liner. Each sleeve for each zone is shifted of actuated using a dropped ball to open a port to the formation. After a zone is fractured using high pressure fracturing fluid, a successive ball is dropped to actuate the next uphole sleeve and the process is repeated. At the completion of the stimulation, retrieval of all balls enables full bore access to the liner for production of hydrocarbons from the formation.
However, use of ball actuation can be problematic for several reasons including the need for retrieval of the balls using a retrieval string, ball loss or ball injection failure among others. Further, for fracturing treatment of tight rock formations, such as those found in the Cardium Formation of West Central Alberta, it can be difficult to cause an initial break down of the rock formation. Thus, in particularly hard rock formations, formation strata may not readily crack or fracture merely with the application of high pressure fluids. Such tight rock formations can require higher fracturing pressures than that which can be supplied by surface equipment of a conventional fracturing or completion string. In such cases, perforation guns are sometimes required in advance of treatment. Perforation guns require additional equipment and time consuming and expensive runs in and out of the wellbore.
Accordingly, there is still a need for reliable access to the formation and means for dealing with difficult formations.

Burst disk-actuated shaped charges, systems and methods of use


The present invention is a flame retardant resin composition including: 100 parts by weight of a resin component (component A) containing at least 50 wt % of a polycarbonate (component A-1) having a unit represented by the formula (A-1), and 1 to 100 parts by weight of an organic phosphorus compound (component B) represented by the formula (1):

Resins such as polypropylenes (PP), acrylonitrile-butadiene-styrene (ABS), polyamides (PA6, PA66), polyesters (PET, PBT) and polycarbonates (PC) are used as raw materials for obtaining resin molded articles. These resins are produced from raw materials obtained from oil resources. In recent years, problems such as the depletion of oil resources and global environment have been concerned, and the production of a resin from a raw material obtained from biogenic matter such as a plant has been desired. Especially when a global environmental problem is taken into consideration, a resin obtained from a plant-derived raw material is regarded as a resin having a low load on the global environment from the concept "carbon neutral" which means that the balance of carbon is neutral in view of the amount of carbon dioxide absorbed during the growth of a plant even when it is burnt after use.
Meanwhile, to use a resin obtained from a plant-derived raw material as an industrial material, especially an electric/electronic-related part, OA-related part or auto part, flame retardancy must be provided to the resin from the viewpoint of safety.
Various attempts have been made for the flame retardation of resins obtained from plant-derived raw materials, especially polylactic acid resin, and a certain measure of flame retardation has been achieved. However, a large amount of a flame retardant is used to flame retard these resins, whereby the physical properties of the resins are impaired.
Meanwhile, as a resin obtained from a plant-derived raw material, a polycarbonate resin prepared from a raw material obtained from an ether diol residue which can be produced from sugar is now under study, in addition to the polylactic acid resin.
For example, an ether diol represented by the following formula (a) is easily produced from sugar or starch, and three stereoisomers of the ether diol are known.

In concrete terms, the stereoisomers are 1,4:3,6-dianhydro-D-sorbitol (to be referred to as "isosorbide" hereinafter in this text) represented by the following formula (b),
1,4:3,6-dianhydro-D-mannitol (to be referred to as "isomannide" hereinafter in this text) represented by the following formula (c),
and 1,4:3,6-dianhydro-L-iditol (to be referred to as "isoidide" hereinafter in this text) represented by the following formula (d).

Isosorbide, isomannide and isoidide are obtained from D-glucose, D-mannose and L-idose, respectively. For example, isosorbide can be obtained by hydrogenating D-glucose and dehydrating it with an acid catalyst.
Heretofore, it has been studied to incorporate especially isosorbide among the above ether diols into a polycarbonate as the main monomer. Particularly isosorbide homopolycarbonates are disclosed by Patent Documents 1 and 2.
Patent Document 1 reports a homopolycarbonate resin having a melting point of 203° C. which is produced by a melt transesterification process. However, this polymer has unsatisfactory mechanical properties.
As an example having high heat resistance, Patent Document 2 reports a polycarbonate having a glass transition temperature of 170° C. or higher measured by differential calorimetry at a temperature elevation rate of 10° C./min. However, it has a high reduced viscosity and involves a problem that its melt viscosity is too high when it is considered as a molding material.
Meanwhile, Patent Document 3 discloses a copolycarbonate of isosorbide and a linear aliphatic diol.
The flame retardancies of the polycarbonates obtained from isosorbide are not studied at all in all of these documents.    (Patent Document 1) UK Patent Laid-opened publication No. 1079686    (Patent Document 2) WO2007/013463    (Patent Document 3) WO2004/111106

Flame retardant resin composition and molded article thereof

Abstract: and a molded article thereof.


An absorbent composite includes a porous base layer, a core layer, and a superabsorbent laminate layer. The core layer has a fluff pulp layer and superabsorbent polymer particles. The core layer is disposed on the base layer. The superabsorbent laminate layer is disposed on the core layer. The base layer, the core layer, and the superabsorbent laminate layer are compressed together and embossed under heat and pressure to form a plurality of embossed depressions. The embossed depressions are arranged across a major surface area of the superabsorbent laminate layer. The embossed depressions extend through the composite from the superabsorbent laminate layer and into the core layer and the base layer. A thin, soft, and pliable absorbent composite suitable for a variety of applications including wound care is thereby provided.

Currently, there are many disposable wound care bandages or dressings being sold in the U.S. and European wound care markets. All disposable wound care bandages utilize an absorbent core to absorb blood, exudate, or other fluids to ensure cleanliness and comfort for the patient. These bandages require as much absorbent ability as possible, which can be achieved through increased loadings of superabsorbent polymer.
Bandages require discreetness, softness, and pliability to ensure patient comfort. However, highly absorbent pads severely lack in this aspect. As the superabsorbent polymer loading increases, the discreetness, softness, and pliability of the overall bandage decreases. Also, the pads become thicker, bulkier, rougher to the touch and are unable to conform to the patient. This is a major flaw of conventional high-performance absorbent cores.
There becomes a trade-off of either a highly absorbent and efficient bandage, or a comfortable, soft, thin and inefficient bandage, which requires changes often. If both characteristics could be achieved, there would be improved performance, efficiency and patient comfort. Improvements for both customer and supplier would be observed.
Currently, the only way premium wound dressings can achieve a highly absorbent product is through the use of thick absorbent cores. Recent swings of the wound care market have desired a thinner, softer, and more pliable product. Other markets also desire thin, soft, and pliable superabsorbent products. This has been an ongoing issue where many absorbent core and airlaid manufacturers have not been able to achieve this high level of absorbency and thinness of product, due to conventional airlaid processes being unable to deposit high concentrations of superabsorbent polymers.
There is a continuing need for an absorbent composite that is thin, soft, and pliable, and yet can achieve a high level of absorbency. Desirably, the absorbent composite may be used for a variety of applications including for wound care, feminine care, protective underwear, incontinence pads and liners, diapers, and food pads.


Disclosed is a semiconductor device has a semiconductor substrate of a first conductivity type in which at least a first element-forming region and a second element-forming region are formed. Wells are formed in respective ones of the element-forming regions of the semiconductor substrate, and the well of at least one element-forming region is of the first conductivity type. A guard ring of a second conductivity type is formed between the wells of the first and second element-forming regions, and a region of the first conductivity type having an impurity concentration lower than that of the well of the one element-forming region is formed between the guard ring and the well of the one element-forming region.

An increase in the integration and functionality of semiconductor devices has been accompanied by the mounting of analog and digital circuits on a single semiconductor substrate constituting a semiconductor device.
When analog and digital circuits are mounted on the same substrate, there are instances where noise generated by the digital circuit penetrates into the analog circuit through the substrate and hampers operation of the analog circuit.
It has been proposed to provide a guard ring between the analog and digital circuits in order to solve this problem.
By way of example, as illustrated in FIG. 9 showing a semiconductor device 200 according to the prior art, it has been proposed to form a P-type semiconductor substrate 201 to have an N-well 202 that constructs an analog-circuit forming region and an N-well 203 that constructs a digital-circuit forming region, and to form a guard ring 204 in the N-well 203 of the digital-circuit forming region (see the specification of Japanese Patent Kokai Publication No. JP-P2001-345428A, referred to as "Patent Document 1" below).
An analog circuit 205 is formed in the N-well 202, and a digital circuit 206 is formed in the N-well 203. According to Patent Document 1, propagation of noise from the digital-circuit forming region to the analog-circuit forming region can be prevented by adjusting the depth of the guard ring 204.
Further, as illustrated in FIG. 10 showing a semiconductor device 100 according to the prior art, it has been proposed to form a P-type semiconductor substrate 101 to have a P-well 102 provided with an NMOS transistor 103 and an N-well 105 provided with a PMOS transistor 104, and to provide an N-type guard ring 106 that is in contact with the P-well 102 and N-well 105 (see the specification of Japanese Patent Kokai Publication No. JP-P2002-76289A, referred to as "Patent Document 2" below). Reference numerals 107, 108 in FIG. 10 denote guard rings.
Since the semiconductor device 200 of Patent Document 1 shown in FIG. 9 is such that the P-type semiconductor substrate 201 is formed to have the N-well 202 that constructs the analog-circuit forming region and the N-well 203 that constructs the digital-circuit forming region, PN junctions are formed between the N-wells 202, 203 and the P-type semiconductor substrate 201. Consequently, the arrangement is such that it is difficult for noise from the digital-circuit forming region to propagate to the analog-circuit forming region.
However, Patent Document 1 does not give any consideration with regard to propagation of noise in a case where the N-well 202 of the analog-circuit forming region or the N-well 203 of the digital-circuit forming region is changed to a P-well and the PN junction is no longer formed. This means that with the structure described in Patent Document 1, it is difficult to suppress the propagation of noise in a case where the N-well 202 of the analog-circuit forming region or the N-well 203 of the digital-circuit forming region is changed to a P-well.
On the other hand, in the semiconductor device 100 described in Patent Document 2 shown in FIG. 10, the P-well 102 is formed in the P-type semiconductor substrate 101. Since the N-type guard ring 106 that contacts the P-well 102 is formed between the P-well 102 and the N-well 105, a PN junction is formed between the P-well 102 and the guard ring 106 and it is presumed that the propagation of noise can be suppressed to a certain extent.
In recent years, however, there has been increasing demand for more reliable suppression of noise propagation, especially for the prevention of noise propagation in the high-frequency region. With the semiconductor device 100, however, it is difficult to satisfy such a demand.
The inventors have conjectured that a large junction capacitance between the N-type guard ring 106 and P-well 102 in the semiconductor device 100 is the reason why propagation of noise (especially propagation of noise in the high-frequency region) cannot be suppressed satisfactorily.


A communication device (e.g., 103) includes a user interface (209), a receiver (203), a controller (205), and a transmitter (201). A user of the communication device uses the user interface to place the communication device in a busy operational mode in which the communication device is not involved in a voice communication, but is nevertheless unavailable to participate in a voice communication. While in the busy mode, the communication device receives a voice communication from a calling device (e.g., 104) and automatically responds with a data message indicating that the communication device is in the busy mode, thereby informing a user of the calling device of the busy status of the called device without disrupting the user of the called device.

Radio communication systems are known to include a radio communication infrastructure and mobile or portable communication devices. Some systems (e.g., cellular systems) primarily support telephone communications, while other systems (e.g., trunked or conventional systems) primarily support dispatch communications. Some systems, such as Motorola's "iDEN" system, provide multiple services, such as telephone, dispatch, data, and short message, all in a single communications platform.
Regardless of the type of system, radio users in the system occasionally need to attend meetings or be in other situations in which they do not wish to be disturbed or interrupted. Cellular systems and normal wireline telephone systems accommodate such desires by providing voice mail service to their users. However, such is currently not the case in dispatch systems. In a dispatch system, when a user wants to be uninterrupted, the user must turn off his or her radio, or mute the audio. Although such action by the user allows him or her to remain undisturbed, the action does nothing to inform the callers that he or she is active in the system, but cannot respond at the moment.
In a dispatch system, when a user turns off his or her radio and another user attempts to contact him or her, the calling user receives a message from the radio communication infrastructure, such as "TARGET NOT AVAILABLE." Such a message is indeterminate because it could mean that the called device is powered off or it could mean that the called device is powered on, but simply out of the system coverage area. Accordingly, since the user of the calling device does not know the exact status of the called device, the user of the calling device continues to attempt to contact the user of the called device. Such retries are an inefficient use of system resources when the called user's intent was to remain undisturbed anyway.
Therefore, a need exists for a communication device and method for determining an operational status thereof that permits the communication device to remain active in the system at all times and that provides determinate feedback to calling device users that are attempting to contact the communication device at times when a user of the communication device does not wish to be disturbed.

Communication device and method for determining a busy status thereof in a dispatch system


The present invention refers to a method for high-purity bottling of beverages and an apparatus for carrying out such a method. For achieving high-purity bottling within a confined space and for reducing the operating expenses in comparison with conventional plants, it is suggested that an immersion bath sterilizer should be connected directly to a rotary filling machine and that the rotary filling machine should be arranged in a clean room, whereas in the area of the bottle conveying path through said clean room ultraclean-room conditions are created.

As is generally known, it is of essential importance in beverage bottling processes that the beverages are bottled such that they keep as long as possible, i.e. bacteria, for example, must be prevented from impairing the keeping time of the products. Certain products, especially microbiologically susceptible products, require a heat treatment so as to achieve a sufficiently good keeping quality. In the case of some products a heat treatment of less than 100.degree. Celsius will suffice (this is referred to as pasteurization), in the case of other products temperatures exceeding 100.degree. Celsius must be applied so as to achieve a good keeping quality of these products. This is referred to as sterilization or autoclaving.
Other beverages, such as lemonades or mineral waters containing CO.sub.2, do, however, not require an increased temperature of the product at the time of bottling. When this type of beverages is bottled, it will suffice to take care that adequately hygienic operating conditions are guaranteed so as to be able to produce packages with keeping quality in the microbiological sense. However, if beverages containing alcohol and/or CO.sub.2 are of such a nature that specific microorganisms may develop and the beverages in question may, consequently, perish, they require an additional equipment of the plant for controlling these microorganisms, e.g. external rinsing, disinfection possibilities and sterile media. Such bottling methods normally comprise the bottling of products such as wine, champagne or beer and also microbiologically susceptible refreshing drinks containing CO.sub.2.
Finally there are so-called cold-sterile or aseptic bottling methods, which are actually the methods dealt with in the present invention. Normally, these methods are used for non-alcoholic beverages and for beverages containing no CO.sub.2. As far as this type of beverages is concerned, not only the classic beverage pests, such as yeasts, moulds, acetic-acid and lactic-acid bacteria, but also pathogenic bacteria (e.g. salmonellae) must be taken into account as pests causing the beverages to perish, especially in the case of products whose main characteristic is a pH value that exceeds 4.5. Hence, these bottling methods require a high-purity bottling process, i.e. in particular also special plants and special measures in the field of process engineering, especially ventilation measures, in order to guarantee a high-purity bottling process. The term "high-purity" in the sense of this application describes a bottling process in an atmosphere which contains only germs in the order of up to a few 100 per cubic meter of air, and especially less than 100; in the following, this will also be referred to as "ultraclean-room conditions". If the terms "clean" or "clean-room conditions" are, however, used, this means a number of germs in the order of 10,000, especially, however, less than 10,000 germs per cubic meter air.
The present invention refers to methods and apparatuses of this type. A characteristic of these methods and apparatuses is also that such methods are normally used for bottling products containing no preservative agents at room temperature and that the packages are not subjected to any thermal aftertreatment.
A known method of this type is described e.g. in European patent application 0120 789. In the case of this European patent application, the stream of bottles is first conducted to a first rinser in a building which is under clean-room atmosphere in its entirety. The area in which the rinser is arranged is under sterile air itself. The bottles are treated in such a way that they are ultraclean. Following this, the bottles are transported along an L-shaped transport path of considerable length through the clean room, whereupon they encounter a second rinser arranged in a room which is again under an ultraclean-room atmosphere. The germs and the bacteria which the bottles picked up on their way through the clean room from the first rinser to the second rinser are here e.g. neutralized. Subsequently, the stream of bottles moves into the filling machine, which is also arranged in the ultraclean room. In addition, a closing machine is provided in the ultraclean room downstream of the filling machine. Since the whole plant, comprising several rinsers with intermediate treatment paths, the filling machine and the closing machine, is arranged in a clean room or ultraclean room atmosphere in its entirety, this has the effect that the measures which have to be taken for observing the respective air conditions are very complicated and expensive. The large volumes of the rooms which must here be maintained ultraclean necessitate high operating expenses. In addition, it is disadvantageous that a second rinser must be used so as to neutralize the germs which the bottles picked up on their way from the first rinser to the second.

Method and an apparatus for high-purity bottling of beverages


A system for producing, dispensing, using and monitoring a hydrogen enriched fuel includes a producing system configured to produce the hydrogen enriched fuel, a vehicle having an engine configured to use the hydrogen enriched fuel, and a dispensing system configured to store and dispense the hydrogen enriched fuel into the vehicle. The system also includes a fuel delivery system on the vehicle configured to deliver the hydrogen enriched fuel to the engine, and a control system configured to control the producing system and to monitor the use of the hydrogen enriched fuel by the vehicle. A method includes the steps of producing hydrogen gas and a hydrocarbon fuel, blending the hydrogen gas and the hydrocarbon fuel into the hydrogen enriched fuel, using the hydrogen enriched fuel in the engine, and tracking emissions during the producing step and during the using step.

Gaseous alternative fuels, such as hydrogen and natural gas, are valued for their clean burning characteristics in motor vehicle engines. A particularly clean burning gaseous alternative fuel known as HYTHANE is formed from a mixture of hydrogen and natural gas. The prefix "Hy" in HYTHANE is taken from hydrogen. The suffix "thane" in HYTHANE is taken from methane, which is the primary constituent of natural gas. HYTHANE is a registered trademark of Brehon Energy PLC. HYTEANE typically contains about 5% to 7% hydrogen by energy. Natural gas is typically about 90+% methane, along with small amounts of ethane, propane, higher hydrocarbons, and "inerts" like carbon dioxide or nitrogen.
Hydrogen and methane are complimentary vehicle fuels in many ways. Methane has a relatively narrow flammability range that limits the fuel efficiency in engine applications utilizing a dilute air/fuel mixture and super-aspiration. It is common to dilute the air/fuel mixture with either excess air or recycled exhaust gases, known as lean-burn and exhaust gas recirculation (EGR), respectively. Super-aspiration is commonly achieved with a turbocharger or other supercharging pump. The addition of even a small amount of hydrogen extends the lean flammability range significantly. Methane also has a slow flame speed, especially in lean air/fuel mixtures, while hydrogen has a flame speed about 8 times faster. Methane is a fairly stable molecule that can be difficult to ignite, but hydrogen has an ignition energy requirement about 25 times lower than methane. Finally, methane can be difficult to completely combust in the engine or catalyze in exhaust aftertreatment converters. In contrast, hydrogen is a powerful combustion stimulant for accelerating the methane combustion within an engine, and hydrogen is also a powerful reducing agent for efficient catalysis at lower exhaust temperatures.
Although pure hydrogen fuel can reduce emissions by up to 100%, in the near term there is an objectionable cost differential between fossil fuels and hydrogen. Hydrogen costs are proportional to hydrogen energy, which may be expressed as a percentage of the energy consumed by the baseline energy system (e.g., a non-hydrogen fueled vehicle). However, hydrogen costs alone do not consider the benefits provided by a hydrogen fuel system. To fully understand the benefits of using hydrogen as a fuel, a larger view of the use and economics of hydrogen is necessary.
The present invention considers the reduction in emissions by a hydrogen enriched fuel. The ratio of percent emissions reduction to percent hydrogen energy, relative to baseline conditions, is a measure of the effectiveness of hydrogen utilization called the leverage factor. Hydrogen leverage is defined as the ratio of [% Emissions Reduction]/[% Baseline Energy Supplied as Hydrogen]. For example, a fleet of 100 natural gas buses converted for operation on pure hydrogen, will have a total reduction in emission of about 7%. This means the leverage of using hydrogen is 7%/7%=1. However, the same fleet could use the same amount of hydrogen (7% by energy), blended with natural gas for all 100 buses, and achieve an emissions reduction of 50% for the entire fleet. In this case, the hydrogen leverage is 50%/7%=7.14, or over 7 times as effective as the pure hydrogen case.
The present invention also considers the complete life cycle of the fuel. For example, a biofuel such as ethanol may reduce the emissions produced by a gasoline engine. However, production of the ethanol may include diesel fuel burned in the farm tractors, burning of the agricultural waste, production of excess carbon dioxide during fermentation and distillation, and more diesel burned in tanker trucks for distribution. The present invention recognizes that all of these emission sources must be considered before any valid comparison can be made between the ethanol fuel and the baseline fuel it is replacing.
Despite persistent interest and significant progress in using hydrogen as a vehicle fuel, it has not yet become an established alternative fuel, like alcohols, propane or natural gas. The present invention is directed to a system that utilizes a "wells to wheels" approach, for producing, dispensing, using and monitoring a hydrogen enriched fuel. With the system of the invention, a life cycle assessment can compare the total environmental impact associated with the production, transportation and use of the hydrogen enriched fuel, relative to any other baseline fuel.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

System and method for producing, dispensing, using and monitoring a hydrogen enriched fuel


The present invention provides compositions and methods for inducing neuronal cell differentiation.

Neurodegenerative diseases and disorders affect millions of people every year. Such diseases include, Alzheimer's Disease, Parkinson's Disease, Multiple Sclerosis, Amyotrophic Lateral Sclerosis (ALS or Lou Gehrig's Disease), Huntington's Disease, Frontotemporal Dementia (Pick's Disease), Prion Diseases, as well as neural diseases and disorders resulting from trauma to the central or peripheral nervous system.
Accordingly, there is considerable interest in the development of stem cell-based therapies for neurodegenerative disease (Abrous et al., Physiol. Rev. 85:523-569 (2005); Picard-Riera et al., J. Neurosci. Res. 76:223-231 (2004); Shors et al., Nature, 410:372-376 (2001); Lie, D. C. et al., Annu. Rev. Pharmacol. Toxicol. 44:399-421 (2004); Jin, K. et al., Proc. Natl. Acad. Sci. USA, 101:343-347 (2004)). However, the molecular mechanisms underlying stem cell fate specification are still poorly understood, and current methods are do not selectively induce differentiation of neural stem cells or neural progenitor cells into neuronal cells. While several agents, including retinoic acid (RA) (Eriksson, P. S. et al., Nature Med. 4:1313-1317 (1998); Palmer, T. D. et al., Mol. Cell Neurosci., 8:389-404 1997), leukemia inhibitory factor (LIF) (Nakashima, K. et al., Science 284:479-482 (1999)) and insulin-like growth factor-1 (IGF-1 (Hsieh, J. et al., J Cell Biol. 164:111-122 (2004)), have been found to direct neuronal, astroglial and oligodendrocytic differentiation, each of these agents are either pleiotropic or have poor activity in vivo.
Thus, there is a need in the art for compositions and methods for inducing selective differentiation of stem cells (e.g., neural stem cells and neuronal progenitor cells) into neurons, both in vivo and in vitro. Moreover, there is a particular need for small molecules that can induce selective differentiation of stem cells into neuronal cells in vivo and in vitro. The present invention satisfies these and other needs.

Compositions and methods for inducing neuronal differentiation


An anti-drain clogging device used to containerize and dispense anti-clogging solution into a drain pipe in a controlled slow flow manner over an extended period of time. The anti-drain clogging device has a main container section for holding anti-drain clogging solution and a dispensing section for directing the anti-drain clogging solution from the container section to the inlet of a drain pipe. The device has both a liquid-tight, stable storage mode that the device is placed in prior to use and an operational mode where the device is adjustably fixed over a drain pipe inlet. In the operational mode, the dispensing section is adjusted to a chosen position over the opening of the drain pipe inlet by adjusting a support collar attached to the device. In this position, anti-clogging drain solution drips from the dispensing section in a controlled, slow manner into the drain pipe to steadily dissolve, layer by layer, the clogging and sediment in the pipe over a period of time.

Clogging of drain pipes is a common problem in both residential homes and commercial businesses. During normal use of drain pipes, liquid flowing through the drain pipes contains solid material or sediment which tends to adhere to the pipes inner surface. If the solid material adhering to the pipe is not periodically removed, the adhering solid material builds-up until the liquid flow rate through the pipe is substantially decreased and back-up of the drain pipe occurs.
In the past, liquid dissolvents were poured down drain pipes in order to dissolve clogging sediment build-up in drain pipes. However, in order for the liquid dissolvent to work most effectively on the sediment build-up on the pipe surfaces, the liquid dissolvent must remain in contact with the sedimennt for a sufficient amount of time to allow the liquid dissolvent to react with and dissolve the clogs. The problem with the past solution to preventing drain pipe clogging is that when the liquid dissolvent was poured into the drain pipe it quickly flowed through the pipe and over the outer surface of the sediment without allowing the dissolvent a sufficient amount of time to remain in contact with the sediment. Instead, due to the speed of the liquid dissolvent flowing by the sediment or clog, only an outer layer of the sediment was removed and substantial sediment remained within the drain pipe unaffected by the liquid dissolvent. Because the clogging often was not removed with one application of the liquid dissolvent, the dissolvent had to be repeatedly poured down the sink on several different occasions by the user of the liquid dissolvent. Having to repeatedly pour liquid dissolvent down a drain pipe was both time consuming and annoying to the user. In addition, a large portion of the liquid dissolvent was wasted when it flowed past the clog without reacting with the clog. Even when the repeated pouring of liquid dissolvent down the drain pipe does increase the flow rate through the drain pipe to an acceptable flow rate, sediment unaffected by the flow dissolvent poured into the drain pipe often remains attached to the drain pipes causing more rapid build-up of clogs within the drain pipe.

Method and apparatus for slowly dispensing a solution for unclogging drains


In an embodiment, a process for data enrichment and matching includes obtaining a first dataset associated with a first user from a first data source, where the first dataset includes records from a structured data source, and obtaining a corresponding second dataset associated with a second user. The process includes enriching at least one of the first dataset and the second dataset. The process includes merging the first dataset and the second dataset including by matching a set of attributes based at least in part on matching corresponding attributes, wherein at least one of the first dataset and the second dataset has been enriched. The process includes outputting the merged data.

Data storage systems such as customer relationship management (CRM) systems are useful for managing data records corresponding an organization's associates such as customers or prospective customers. Many different data storage systems exist today. Reconciling data from different systems is technically challenging because different storage systems may store datasets in different ways and use different structuring paradigms. Conventional techniques for combining distinct datasets are typically inaccurate or inefficient.


The present disclosure relates to a method for manufacturing an apparatus for determining and/or monitoring temperature of a medium comprising method steps as follows: arranging a sensor element in a sensor head, producing a vacuum in an internal volume of the sensor head, introducing at least one fill material into at least a portion of the internal volume of the sensor head, and closing the sensor head. The present invention relates, moreover, to a correspondingly manufactured apparatus.

Thermometers are known from the state of the art in the most varied of embodiments. Thus, there are thermometers, which for measuring temperature use the expansion of a liquid, a gas or a solid with known coefficient of expansion, or even such, which relate the electrical conductivity of a material to the temperature, such as, for example, in the case of application of resistance elements or thermocouples. In contrast, in the case of radiation thermometers, especially pyrometers, the heat radiation of a substance is utilized for determining its temperature. The various underpinning measuring principles have already been described in a large number of publications.
In the case of a temperature sensor in the form of a so-called thin film sensor, especially a Resistance Temperature Detector (RTD), a sensor element equipped with connection wires and mounted on a substrate is used, for example, wherein the rear side of the support substrate is, as a rule, coated with metal. Used as sensor elements, in such case, are so-called resistance elements, for example, in the form of platinum elements, which, among others, are obtainable commercially under the labels, PT10, PT100, and PT1000.
The resistance elements are frequently installed by means of a soldering method within a sensor head, for example, a sensor tip, and especially on the inner floor of a sleeve of, e.g., stainless steel. Corresponding thermometers are manufactured and sold by the applicant, for example, under the mark, Quicksens.
Performed as soldering method in many cases is a so-called SMD soldering, in the case of which, firstly, a solder is mounted on a first component and then a second component superimposed and, by heating, soldered to the first component. For the example of a sensor head of a resistance thermometer, usually, firstly, a defined amount of solder in the solid state (e.g in the form of a small disk of solder) is placed in the sensor head and by subsequent heating melted on the inner floor of the sensor head. The sensor element is then immersed in the solder with its metallized face and, in this way, soldered to the inside of the sensor head. Methods for the manufacture of such a soldered connection for a thermometer are known, for example, from the patent disclosures DE102006048448A1 and DE102015112199A1. Fundamentally in the case of a corresponding resistance thermometer, the soldered connection has a large influence on the thermal properties of the thermometer, especially the thermal coupling between resistance element and sensor head.
Alternatively to thermometers, in the case of which the resistance element is soldered to the sensor head, there are numerous thermometers, in the case of which the temperature sensors are embedded and/or encapsulated, especially in ceramic powders, such as, for example, magnesium oxide (MgO) or aluminum oxide (Al2O3), or in a ceramic potting material, especially a curing ceramic potting material. Also such thermometers are manufactured and sold by the applicant, for example, under the mark, Strongsens. The encapsulations or potting serves for securing the temperature sensors. Moreover, for example, the connection lines of the temperature sensor are insulated from one another and from the housing of the sensor head, especially a sensor tip, even at high temperatures, especially at temperatures, for instance, up to 600° C. A method for manufacturing a thermometer embodied in such a manner is known, for example, from patent disclosure DE02329239A1. In order to cast the temperature sensor, predeterminable amounts of first and second components of a potting material are introduced into a mold, especially a mold in the form of a sensor tip. Then, the sensor tip is shaken and/or caused to oscillate with a predeterminable frequency.
Advantageously, resistance thermometers, whose temperature sensor is soldered to the sensor head, have especially good response times for reacting to a change of the temperature of a medium. Corresponding thermometers are, however, disadvantageously not suitable for measuring high temperatures, especially temperatures T>200° C. Also such thermometers have, in comparison with thermometers, in the case of which the temperature sensor is embedded and/or encapsulated, a significantly lesser mechanical stability. Thermometers with embedded and/or encapsulated temperature sensors have, however, disadvantageously worse response times in comparison with thermometers with soldered temperature sensors.


A film includes a first layer including polyvinyl chloride; and a second layer including a material such as anhydride functionalized polyolefin, ethylene/vinyl acetate copolymer having a vinyl acetate content of between 10% and 35%, ethylene/alkyl acrylate copolymer having an alkyl acrylate content of between 10% and 30%, ethylene/alkyl methacrylate copolymer having an alkyl methacrylate content of between 10% and 30%, ethylene/acrylic acid copolymer having an acrylic acid content of between 10% and 30%, ethylene/methacrylic acid copolymer having a methacrylic acid content of between 10% and 30%, and ionomer. A layer of polyolefin, and/or an additional layer including any of the materials of the second layer, or polyvinyl chloride, can be optionally included in a film of the invention.

The present invention is directed to a new and useful film. Films, and especially heat shrinkable films are well known for many packaging applications.
Examples of such films are the polyolefinic films supplied commercially by Cryovac, Inc. These films have proven to be very useful in pack- aging applications where high shrink, good optics, impact resistance, tear initiation and tear propagation resistance are needed. Films of this type are disclosed in U.S. Pat. Nos. 4,551,380 and 4,643,943, both to Schoenberg, incorporated herein by reference in their entirety.
Polyvinyl chloride (hereinafter "PVC") films are also widely used in packaging applications.
PVC films exhibit good elastic recovery, high modulus, and low shrink tension, but poor sealability, and poor tear resistance. They also carbonize during a trim sealing process.
It would be desirable to provide a film having the good sealaibility and tear resistance properties of polyolefinic films, but with the good elastic recovery, high modulus, and low shrink tension of PVC films.

Multilayer film with polyolefin and polyvinyl chloride


Disclosed are various approaches for facilitating single sign-on (SSO) for third-party services that are accessible through messages (e.g., email) received by a user. A user can receive a message that includes an embedded URL or link that opens in a third-party service that requires authentication. Instead of requiring the user to enter authentication credentials for accessing the third-party service, a tunnel service can be used to intercept requests for authentication and redirect the requests to an identity manager that can issue a SSO token following an authentication of the user and device. Upon supplying the third-party service with the SSO token, the user can access the content associated with the third-party service without entering authentication credentials.

With the emergence of bring-your-own-device (BYOD) technology in the workplace, enterprises permit employees or other personnel to use their own devices for business purposes. This can include accessing enterprise data, such as email and corporate documents. However, prior to an employee using his or her own device in the workplace, a company can require the employee to enroll with a management service capable of protecting enterprise data from theft, loss, and unauthorized access.
In the enterprise setting, individuals can utilize a number of different services and applications that are provided by the enterprise. Some of these services are hosted in a third-party environment and some can be hosted on servers operated by the enterprise. These individuals can use authentication credentials to login to these application or services. For example, a user might have an email account or an account with a third-party customer relationship management service. Accessing data within these services can be accomplished through a device with which the user is authenticated and which may have an authentication token associated with the user's identity.
However, in some situations, a user may receive an email, or other type of message, that includes an embedded uniform resource locator (URL) or a link, that upon selection, opens in another application and requires a user to enter his or her credentials for the application. However, the user may access the email from a device other than the device that contains the authentication token that allows for access to the service. For example, the authentication token may be set up on a user's desktop and the user accesses the email through his or her mobile device. In another example, the user may be outside his or her enterprise which may require additional authentication if the user is outside the enterprise network. As such, the user may not be able to access the data immediately or the user will have to enter authentication credentials that are not normally required. Further, the embedded URL or link may open an application that may need to be installed or otherwise set-up on the user's device. As such, the user may be unable to immediately access the data associated with the link. Being unable to immediately access the data associated with the service or having to continually enter authentication credentials can be frustrating to a user over time.

Single sign on (SSO) capability for services accessed through messages


An image sensor with a vertically integrated thin-film photodiode includes a bottom doped layer of a PIN photodiode imbedded in a dielectric layer, wherein a bottom surface of the bottom doped layer completely contacts its corresponding underlying pixel electrode. The bottom doped layers of the PIN photodiodes are formed by a self-aligned and damascene method, therefore the pixel electrodes are not exposed to the I-type amorphous silicon layer of the PIN photodiodes. Moreover, the transparent electrode connects the PIN photodiodes to an external ground voltage power through a ground pad which is a portion of a top metal layer.

1. Field of the Invention
This invention relates generally to an image sensor. In particular, it relates to an image sensor with a vertically integrated PIN thin-film photodiode.
2. Description of the Related Art
Solid state image sensors, which are used in applications such as digital cameras, are currently available in numerous forms. Charge coupled devices (CCD) and CMOS image sensors, for example, are based on a two dimensional array of pixels. Each pixel contains a light sensing device that is capable of converting an optical image into an electronic signal. When photons strike the photoactive region of the array, free charge carriers are generated in an amount that is linearly proportional to the incident photon radiation. The photon generated charge carriers are collected and moved to output circuitry for processing. The pixels are typically disposed in rows and columns to form the array.
Integration of the image sensors with signal processing circuitry has become more important because integration enables miniaturization and simplification of imaging systems. Integration of image sensors along with analog and digital signal processing circuitry allows electronic imaging systems to be low cost, compact and require low power consumption.
Typical prior art CMOS image sensors in use rely on a lateral integration of the photodetector and the pixel electronics. In a laterally integrated CMOS image sensor, the photodetector and the CMOS circuitry are fabricated next to each other on the silicon substrate. Thus, additional lateral area ("real estate") is required for the lateral integration of the photodetector with the CMOS circuitry. This can reduce the area fill factor and limit the possible resolution. Furthermore, it is difficult to optimize the process technology for both the CMOS transistor and for the photodiode at the same time. For example, while the design of fast CMOS circuits demands the use of shallow junctions with very low sheet resistance, these junctions are totally inconsistent for use as a photodiode. Also, when additional on-chip functions are added to the sensors, either the pixel size will increase to maintain the sensitivity of the sensor or the area required for the photodiode will decrease to maintain the pixel size. If the pixel size increases to maintain the sensitivity, the resolution of the sensor will decrease. If the photodiode area decreases to maintain the pixel size, the sensitivity of the sensor may decrease.
In a laterally integrated CMOS image sensor, as the pixel size is shrunk and multi-layer metal is used to increase circuit density and realize camera-on-chip, the photosensitivity of the image sensor is degraded due to light scattering, low fill factor (which is the ratio of photodetector area to pixel area) and destructive difference (different refraction index, n, dielectric film used in ILD/IMD).
Recently, vertically integrated thin film photodiode has been used to increase photosensitivity.
In U.S. Pat. No. 6,288,435 to Ping Mei et al, the occurrence of vertical leakage current if the metal line (contacting the data line) is exposed to the intrinsic amorphous silicon is discussed, and a continuous amorphous silicon layer sensors using a wider N+ amorphous silicon layer sealing the metal line or using a doped polysilicon back contact to reduce vertical leakage current is taught. However, the former method needs another mask to generate a wider N+ amorphous silicon layer, and the latter method increases the electric resistance between the PIN element and the data line. Moreover, a multi-layer metal interconnection structure is also needed as the pixel size is shrunk, so as to realize camera-on-chip.
U.S. Pat. No. 6,018,187 to Jeremy A. Theil et al discloses that a conductive lead connected between a bias circuit and the transparent conductive layer contacting the PIN photo diodes is not a reliable connection structure. An elevated PIN diode active pixel sensor including a reliable interconnection structure between the pixel sensor and the substrate is therefore taught. The transparent conductive layer is electrically connected to the substrate through a conductive plug and a bonding pad is designed. Further, an inner metal section is optionally formed between each pixel electrode and the underlying conductive plug to lower resistance to obtain better current collection. However, if the inner metal section is formed to lower resistance between the PIN element and the underlying interconnection, another processing step is needed.
Accordingly, the present invention pertains to the vertical integration of photodetectors with CMOS circuitry with reliable structure, fewer masks and decreased process cost.

Image sensor with vertically integrated thin-film photodiode

Taiwan Semiconductor Manufacturing Co., Ltd.