Each pixel of an EL display panel includes a diode element, an organic EL element, and a capacitor. The cathode of the diode element, the anode of the organic EL element, and one of the electrodes of the capacitor are electrically connected to one another at a common terminal. The anode of the diode element is connected to a signal electrode. The other electrode of the capacitor is connected to a scanning electrode. The cathode of the organic EL element is connected to the scanning electrode. A forward direction of the diode element and a forward direction of the organic EL element coincide. The voltage between the scanning electrodes is controlled to control the current flowing through the organic EL element. As a result, it is possible to provide an emitter having stable luminance with improved efficiency, and an emitting device and a display panel employing such an emitter.

Display panels employing a self-emitting emitting element, as represented by an organic EL (Electro Luminescence) display panel or an FED, have a promising future as a candidate for a flat display panel which can match up against liquid crystal displays.
FIG. 19(a) and FIG. 19(b) show structures of a blue-color emitting organic EL element which was introduced in the SID 97 DIGEST pp. 1073–1076. FIG. 19(a) is a cross sectional view showing a structure of a conventional blue-color emitting organic EL element 311, and FIG. 19(b) is a structural formula of an emitting layer 307 of FIG. 19(a).
The blue-color emitting EL element 311 has a structure in which a transparent anode (transparent electrode) 302 such as ITO is formed on a glass 301, and an organic multi-layered film 304 is formed thereon. On the organic multi-layered film 304 is formed a cathode 303 such as Al. Among several structures of the organic multi-layered film 304 the foregoing publication adopts a structure in which a hole injecting layer 305, a hole transporting layer 306, an emitting layer 307, and an electron transporting layer 308 are stacked on the anode 302. Further, the foregoing publication discloses a structure for realizing full-color display by subjecting the monochromatic blue color luminescence to color-conversion with the use of a color-conversion filter. The emitting layer 307 has such a structure with the structural formula (biphenyl (DPVBi: provided by Idemitsu Kousan Co., Ltd.)) as shown in FIG. 19(b).
FIG. 20 is a structure of a conventional emitting organic EL element of three colors R, G, and B, as taught by NEC TECHNICAL JOURNAL Vol. 51 No. 10/1998 pp.28–32 (published date: Oct. 23, 1998), showing a cross sectional view of a pixel structure of the emitting organic EL element of three colors R, G, and B. Note that, in FIG. 20, structural elements which are analogous to those shown in FIG. 19(a) are given the same reference numerals. On a glass 301 is formed a transparent anode 302 such as ITO (the structure is upside down in FIG. 20), and an organic multi-layered film 304 is formed thereon. On the organic multi-layered film 304 is formed a cathode 303 such as Al. Among several structures of the organic multi-layered film 304, the foregoing publication adopts a structure in which a hole transporting layer 306, an emitting layer 307, and an electron transporting layer 308 are stacked on the anode 302. Further, in this publication, a hole injecting layer (not shown) and the hole transporting layer 306 are made of an aromatic amine material. That is, Further, in the emitting layer 307, a red emitting layer 307R is made of a G (green) emitting material as a host doping a pigment DCM for a red (R) laser, and a green emitting layer 307G and a blue emitting layer 307B are made of an aromatic amine material. The electron transporting layer 308 is made of a metal complex material.
Various other materials for the organic multi-layered film 304 can be found in many Japanese Unexamined Patent Publications, including, for example, Tokukaihei 5-70773 (published date: Mar. 23, 1993), Tokukaihei 5-198377 (published date: Aug. 6, 1993), and Tokukaihei 6-172751 (published date: Jun. 21, 1994).
FIG. 21 is a perspective view showing a structure of a simple-matrix-type EL panel (EL display panel) using such an organic EL element. Specifically, a plurality of anodes 2 extending in one direction and the cathodes 3 extending in a direction orthogonal to the anodes 2 are formed on a glass 1 with the organic multi-layered film 4 therebetween, thus making the simple-matrix-type EL panel, with the areas of intersections of the anodes 2 and the cathodes 3 making up pixels.
FIG. 22 is a graph showing a relation between a voltage between the cathode 303 and the anode 302 (cathode-anode voltage) and a current through the emitting layer 307 in the organic EL element as shown in FIG. 19 and FIG. 20. Also, FIG. 23 is a graph showing a relation between a current through the emitting layer 307 and luminance. As shown in FIG. 23, in the organic EL element, the current through the emitting layer 307 and the luminance are nearly proportionally related, which, however, is not the case for the relation between the cathode-anode voltage and the current through the emitting layer 307, which varies depending on such factors as temperature, as shown in FIG. 22.
Thus, the organic EL element is preferably driven by controlling current, rather than voltage, to stabilize luminance. As such is the case, the column (data) driver circuit for driving the organic EL element preferably has a structure as shown by a current-controlling driver circuit 116 in FIG. 24. FIG. 24 is a block diagram showing a structure of the matrix-type EL panel.
Here, the current-controlling driver circuit 116 is structured such that the voltage generated by the column driver circuit 112 is converted to current by a current control circuit (variable constant current circuit) 115. Apart from the question as to whether such a structure is preferable or not, the use of a current-controlling driver circuit is nonetheless preferable in the organic EL element.
In this structure, the current-controlling driver circuit 116 is connected to the anodes 2 of the EL panel 110 (as shown in FIG. 2), and a row (scanning) driver circuit 111 is connected to the cathodes 3, thus structuring the matrix-type EL panel. Note that, the column driver circuit 112 has a structure wherein a shift register 113 receives data according to luminance of respective colors R, G, and B (red, green, and blue), which are then transferred by a clock CLK and held in a sample hold circuit 114 by a data hold timing pulse LP, and a current is outputted from the current control circuit 115 based on this data.
A driving method of such a matrix-type EL panel of a simple matrix structure is disclosed in PIONEER R&D Vol. 8 No. 3, pp.41–49 (published date: Dec. 31, 1998). The following describes a driving method of the simple-matrix-type EL panel with reference to FIG. 25. FIG. 25 is a circuit diagram showing a driving circuit of the simple-matrix-type EL panel.
The potential of a selected row (scanning) electrode K2 is dropped to a GND potential, and the other row electrodes are set to a specific potential (here, about 10 V). Display is carried out in such a manner that constant currents are flown through column (data) electrodes A2 and A3 of their respective pixels E2.2 and E2.3 to be displayed, and the column electrodes which correspond to pixels not to emit light are set to an open state.
Further, in order to carry out multi-tone display on pixels, the current supplied from the column electrode is controlled according to a tone level to be displayed on the pixel. This current control is carried out by (1) a current value modulation tone control method, in which the intensity of the current outputted to the column electrodes (anodes 2 in FIG. 24) from the current control circuit 115 is changed according to the luminance of pixels to be displayed, and (2) a pulse width modulation tone control method, in which a supply time of a current is changed according to the luminance of pixels to be displayed, while holding the currents outputted to the column electrodes at a constant level.
Meanwhile, a structure of an active-matrix-type EL panel using diodes is shown, for example, in Tokukaihei 10-268798 (published date: Oct. 9, 1998).
FIG. 26 shows an equivalent circuit of a pixel of the EL panel of this publication. FIG. 26 is a circuit diagram showing an equivalent circuit of the active-matrix-type EL panel using diodes. A pixel 12 includes an organic EL element 13, an additional capacitance (auxiliary capacitance) 14, an additional resistance 15, and an MIM (Metal Insulator Metal) diode 16 as the pixel driving element.
The pixel 12 of the EL panel has a structure as shown in FIG. 27(a) and FIG. 27(b), in which FIG. 27(a) is a plan view showing the structure of the pixel 12 of FIG. 26, and FIG. 27(b) is a cross sectional view, taken along the line A—A of FIG. 27(a). The MIM diode 16 has a stacked structure of a cathode electrode 21 made of tantalum, an insulating film 22 made of a silicon oxide film, and an anode electrode 23 made of chrome, and is formed on an insulating substrate 31. The additional resistance 15 is made up of a wiring layer which is formed on the insulating substrate 31, making up a portion of the anode electrode 23 of the MIM diode 16 extending on the insulating substrate 31.
The additional capacitance 14 is composed of electrodes 41 and 42 opposing each other, and an insulating film 43. The electrode 41, made of tantalum, is formed on the insulating substrate 31. On the electrode 41 is formed the electrode 42, made of chrome, via the insulating film 43 made of a silicon oxide film. Further, the electrode 42 is connected to the wiring layer making up the additional capacitance 15. Here, the electrode 41 is formed simultaneously with the cathode electrode 21 of the MIM diode 16, and the electrode 42 is simultaneously formed with the anode electrode 23 of the MIM diode 16, and the insulating film 43 is simultaneously formed with the insulating film 22 of the MIM diode 16.
The organic EL element 13 has a stacked structure of an anode 51 made of a transparent electrode such as ITO, a hole transporting layer 52, an emitting layer 53, an electron transporting layer 54, and a cathode 55 made of aluminium alloy. The hole transporting layer 52, the emitting layer 53, and the electron transporting layer 54 are made of organic compounds. The cathode 55 is formed on the electrode 42 making up the additional capacitance 14, via the insulating film 56 made of a silicon oxide film. Further, the cathode 55 is connected to the anode electrode 23 of the MIM diode 16 via a contact hole 57 which is formed through the insulating film 56. The anode 51 is connected to the electrode 41 of the additional capacitance 14 via a contact hole 58 which is formed through the insulating film 43 and the insulating film 56.
A structure of the foregoing EL panel and a driving system of the EL panel is shown in FIG. 28. FIG. 28 is a block diagram showing a structure of the active-matrix-type EL panel using diodes.
An EL display device 84 includes an EL panel 81, a gate driver 82, and a drain driver (data driver) 83. On the EL panel 81 are disposed gate wires (scanning lines) G1, . . . , Gn, Gn+1, . . . , Gm, and drain wires (data lines) D1, . . . , Dn, Dn+1, . . . , Dm. The gate wires G1 through Gm and the drain wires D1 through Dm are orthogonal to each other, and the areas where they cross each other make up pixels 12. That is, the EL panel 81 is made up of the pixels 12 which are disposed in a matrix pattern. The gate wires G1 through Gm are connected to the gate driver 82 for receiving gate signals (scanning signals). Further, the drain wires D1 through Dm are connected to the drain driver 83 for receiving data signals.
Here, the gate wires G1 through Gm are made up of cathode electrodes 21 of the MIM diode 16. Further, the drain wires D1 through Dm are made up of electrodes 41 of the additional capacitance 14 extending on the insulating substrate 31 (FIG. 27(a) and FIG. 27(b)).
The following describes a driving method of the EL panel 84 with reference to FIG. 26 through FIG. 28. By controlling the voltage of the gate wire Gn so that the voltage between the gate wire Gn and the drain wire Dn becomes higher than the threshold voltage of the MIM diode 16, the MIM diode 16 becomes conducted. This sets off charging the electrostatic capacitance of the organic EL element 13, and the additional capacitance 14 by the data signal applied to the drain wire Dn, thus applying the data signal to the pixel 12. This data signal drives the organic EL element 13, and the organic EL element 13 emits light as a result.
On the other hand, when the voltage of the gate wire Gn is controlled so that the voltage between the gate wire Gn and the drain wire Dn becomes lower than the threshold voltage of the MIM diode 16, the MIM diode 16 becomes non-conducted. In this case, the data signal which had been applied to the drain wire Dn up to this time is held in the form of a charge by the electrostatic capacitance of the organic EL element 13, and the additional capacitance 14. By thus supplying data signals to be applied to the pixels 12 to the drain wires D1 through Dm, and by controlling the voltages of the gate wire G1 through Gm, any data signal can be held by the pixels 12. The organic EL element 13 can be driven continuously, i.e., can emit light, until the MIM diode 16 becomes non-conducted again.
Further, a structure of the active-matrix-type EL panel using a FET (Field Effect Transistor), or, in particular, a thin film transistor (TFT) is shown, for example, in Tokukaihei 8-234683 (published date: Sep. 13, 1996).
An equivalent circuit of the EL panel as disclosed in this publication is shown in FIG. 29. FIG. 29 is a circuit diagram showing an equivalent circuit of pixels of the EL panel of the active-matrix-type EL panel using TFTs. A two-dimensional structure of pixels of the EL panel is as shown in FIG. 30. FIG. 30 is a plan view of pixels of the active-matrix-type EL panel using TFTs.
Each pixel 212 of the EL panel includes two TFTs 213 and 214, a memory capacitor 215, and an organic EL element 216. The source of the TFT 213 is connected to a source bus (column electrode, source line 152), and the gate of the TFT 213 is connected to a gate bus (row electrode, gate line 151). To the drain of the TFT 213 are connected in parallel one of the terminals of the memory capacitor 215 and the gate of the TFT 214. The other terminal of the memory capacitor 215 and the source of the TFT 214 are connected to a ground pass 153, and the drain of the TFT 214 is connected to the anode (EL anode layer 418) of the organic EL element 216. The cathode of the organic EL element 216 is connected to a negative power source (not shown).
The TFT 214 and the memory capacitor 215 of the EL panel as shown in FIG. 30 has cross sectional structures as shown in FIG. 32 and FIG. 33, respectively. FIG. 32 is a cross sectional view taken along the line B—B of FIG. 30, and FIG. 33 is a cross sectional view taken along the line C—C of FIG. 30. The TFT 214 and the memory capacitor 215 are fabricated as follows.
A polysilicon layer 411 is deposited on a transparent insulating substrate 410 made of a material such as crystal or low-temperature glass, and the polysilicon layer 411 is patterned in the form of an "island" by photolithography. Then, an insulating gate material 412 such as silicon dioxide is deposited in the thickness of about 1000 Å on the surfaces of the polysilicon layer 411 of the island shape and the insulating substrate 410.
Then, a polysilicon layer 413 made of amorphous silicon is deposited on the gate insulating layer 412, and is patterned by photolithography on the polysilicon island so that source and drain areas are formed in the polysilicon area after ion implantation. The ion implant is conducted with an N-type dopant, for which arsenic is used. The polysilicon gate electrode 413 also serves as a base electrode 413a of the capacitor 215. The gate bus 414 is made of metal silicides such as tungsten silicide (WSi2) and is patterned.
Thereafter, an insulating layer 415 such as silicon dioxide is deposited over the entire surface of the device. A portion of the insulating layer 415 is used to form contact holes 416a and 417a, etc., so as to provide a junction in the thin film transistor. An electrode material 416, which is provided in contact with the source area of the TFT 214, also makes up an upper electrode 416b of the capacitor 215. The source bus and the ground bus are also formed on the insulating layer 415. The EL anode layer (transparent electrode) 418 made of a material such as ITO is in contact with the drain area of the TFT 214, and makes up an anode of the organic EL element 216.
Then, an insulating passivation layer 419 such as silicon dioxide is deposited on the surface of the device in the thickness of about 0.5 μm to about 1 μm. The passivation layer 419 is tapered toward an edge 420 on the side of the ITO. The organic EL layer 421 is deposited on the passivation layer 419 and the EL anode layer 418. Finally, the cathode 422 of the organic EL element 216, which is made of a metallic material such as aluminium is deposited on the surface of the device.
The organic EL layer 421 is available in several different structures. For example, the foregoing Tokukaihei 8-234683 discloses a structure of organic EL layer 421 which includes organic hole injection and a moving band in contact with an anode, and electron injection and a moving band for forming a junction with the organic hole injection and the moving band. The Tokukaihei 8-234683 also discloses a structural formula of such an organic layer.
The foregoing circuit operates in the following manner. A voltage for switching ON the TFT 213 is applied to the gate line 151. Then, the TFT 214 is switched ON while accumulating the supplied charge from the source line 152 in the memory capacitor 215. The conduction state of the TFT 214 is also controlled by the stored charged in the memory capacitor 215, even after the TFT 214 is switched OFF, so as to control the current flow through the organic EL element 216.
FIG. 23 shows that the luminance of the organic EL element is nearly proportional to the current. In relation to this, the applied voltage to the organic EL element is related to luminance or luminous efficiency as shown in FIG. 31. FIG. 31 is a graph showing a relation between the applied voltage to the organic EL element, and luminance or luminous efficiency.
The luminous efficiency is determined as follows. Luminance L of the organic EL element and current I through the organic EL element are related byL=A(I)×I(where A(I) is a function which approaches zero when current I is small, and which takes a constant value when current I exceeds a certain value). Further, power consumption W of the organic EL element is related to applied voltage V and current I byW=V×I.Thus, luminous efficiency L/W of the organic EL element isL/W=(A(I)×I)/(V×I)=A(I)/V  (1).
For example, as shown in FIG. 31, the luminous efficiency L/W takes the value 22 [lm/W] at the applied voltage of 3 [V], at which the luminance is 100 [cd/m2]. Further, the luminous efficiency is 15.5 [lm/W] at the applied voltage of 4.4 [V], at which the luminance is 1000 [cd/m2]. This behavior wherein the luminous efficiency L/W once increases with increase in potential V and then decreases can be explained by the function A(I), which shows an abrupt increase with increase in current I up to a certain current I, and which takes almost a constant value above this current I. Further, it can be speculated that the luminous efficiency L/W shows the maximum value in the vicinity of where the function A(I) takes almost a constant value.
In the structure of the simple-matrix-type EL panel, when the number of scanning lines is m, the duration of emission of the organic EL element making up the pixel is only 1/m of the total scanning period. Thus, in order to obtain the same luminance in this pixel as that of a device of a constant-luminescence-type, each duration of emission needs to show spontaneous luminance m times that of the constant-luminescence-type device.
In general, the luminance of white display in laptop personal computers, etc., is around 100 [cd/m2]. Thus, when the number of scanning lines is 100 or more, the required spontaneous luminance for the pixel exceeds 10000 [cd/m2].
However, in the currently available organic EL elements, as shown in FIG. 31, the spontaneous luminance (luminance L) at which the luminous efficiency L/W becomes maximum is around 10 to 100 [cd/m2]. Thus, when such an organic EL element is to be used in a display with the number of scanning lines exceeding 100, the organic EL element needs to be used at low luminous efficiency L/W in the simple-matrix-type EL panel.
In view of this drawback, the active-matrix-type EL panel using diodes as disclosed in the foregoing Tokukaihei 10-268798, and the active-matrix-type EL panel using FETs as disclosed in the foregoing Tokukaihei 8-234683 intended to increase the duration of emission of the organic EL element larger than 1/m of the total scanning period.
However, in the equivalent circuit as shown in FIG. 26, which is the EL panel using diodes, the equivalent circuit will be in the form of an RC serial circuit (resistance-capacitance serial circuit) when the MIM diode 16 becomes non-conducted. Here, the capacitance (capacitance value C) corresponds to the additional capacitance 14 of FIG. 26, and the resistance (resistance value R) presumably corresponds to the sum of the additional resistance 15 (resistance value r) of FIG. 26 and the internal ON resistance of the organic EL element 13 during conduction.
The current I(t) through the organic EL element 13 isI(t)=(qo/RC)exp(−t/RC)  (2)(where t is the elapsed time from the beginning of the non-conduction state of the MIM diode 16, and qo is the charge held in the additional capacitance 14 when time t=0). The charge qo held in the additional capacitance 14 and the voltage Vo generated in the additional capacitance 14 are related byVo=qo/C.
In order to improve luminous efficiency over the simple-matrix-type panel, assuming that the voltage Vo is decided by the withstand voltage of the source driver, it can be seen from equation (1) that the peak value of current I(t) (current I(0)=Vo/R when t=0) needs to be reduced. This requires that the resistance value r of the additional resistance 15 be increased. Note that, since luminance is decided by charge (charge=current value×discharge time at this current value), the luminance will not be changed even when the current is decreased, as long as the discharged charge is constant (because the discharge time is usually short).
However, when the resistance value r of the additional resistance 15 is increased, the time constant RC of the equivalent circuit of FIG. 26 is increased as well. This causes the problem of increased time period for charging the additional capacitance 14. This problem can be solved by increasing the voltage supplied from the source driver, which, however, requires the source driver to have a high withstand voltage, and causes another problem of increased cost of the source driver.
Further, comparing the charging by decreasing the resistance value of the additional resistance 15 and the voltage supplied from the source driver, with the charging by increasing the resistance value of the additional resistance 15 and the voltage supplied from the source driver, the intensity of the current I(t) and the way it flows will be the same between these two methods, provided that the stored charge in the capacitance (capacitance value C) and the charging time are both constant. Since the calorific value of the additional resistance 15 is decided by the product of the square of current and the resistance value, the problem of calorific value in the charging time will be caused as the resistance value is increased.
Further, in this case, the current I(t) through the organic EL element 13 shows an exponential change. Thus, the high luminous efficiency state of the organic EL element 13 cannot be maintained constantly, and further, the low luminous efficiency state may be caused by the change in current I(t). Thus, it is difficult to sufficiently improve the luminous efficiency as with the foregoing case.
Increasing the additional resistance also poses a problem in particular that the generated heat by the current flow through the additional resistance 15 during the charging/discharging period of the additional capacitance C does not contribute to luminescence.
Meanwhile, the active-matrix-type EL panel using TFTs has the following problems. In the active-matrix-type EL panel, the threshold characteristics between the gate and source of the TFT 214 in the equivalent circuit of FIG. 29 do not become uniform within the panel and there is a variance. This variance further causes a variance in a voltage drop between the source and drain, or between the gate and drain, which results in variance in luminance of the organic EL element 216 in the panel.
Further, in this case, the organic EL element 216 is driven by voltage control. Thus, compared with the foregoing case where the organic EL element 216 is driven by current control, luminance becomes instable.
Further, in the case where the organic EL element 216 is displaying tones under the control of the gate voltage of the TFT 214, the current flow through the organic EL element 216 is varied according to the tone level. As a result, the luminous efficiency of the organic EL element 216 is changed according to tones, failing to drive the organic EL element 216 by the current of a range which intends to increase luminous efficiency. Thus, it is also difficult in this case to sufficiently improve luminous efficiency.

Emitter, emitting device, display panel, and display device


System and method to analyze and predict impact of textual data are provided. The system also includes a processing subsystem configured to select textual data from a plurality of data sets stored in a memory, to extract data from external sources using crawling, to identify at least one context of the textual data using one or more identification methods. The processing subsystem includes an NLP module configured to match the textual data with NLP frameworks using a mapping method based on a plurality of parameters, to apply feature engineering and transformation on the textual data to extract a plurality of features from the plurality of data sets and to analyze matched textual data of the textual using at least one analysis method. The processing subsystem also includes a predictive module configured to predict one or more future values of the analyzed textual data using the one or more predictive methods.

Natural Language Processing is a type of analysis method in Machine Learning or Artificial Intelligence which deals with extracting information from unstructured data and using extracted data to analyze and predict various trends and behavioural pattern and its influence on business performance.
In one approach, the system includes a processor configured to identify a process to analyze data received from a source. Moreover, the data received from the source is a type of unstructured data which is in a form of natural language. Furthermore, the system searches and matches a Natural Language Processing (NLP) framework to predict and analyze the data received. However, the data received from the source could be either internal or external. Also, the data received does not depend on a use case or a specific context which lowers an efficiency of the system. Furthermore, the system requires a special set of instructions to analyze and predict the data, which involves high dependency on manual task from a user. Such dependency causes another factor to lower the efficiency of the system and also slows down the system. Moreover, in such system, the user must correlate the derived insights obtained during analysis of the data with the key performance indication. Such correlation by the user is yet another factor for less efficiency and delay of the system.
Hence, there is a need for an improved system and method to analyze and predict impact of textual data to address the aforementioned issue.

System and method to analyse and predict impact of textual data


A quick connect device for coupling a vent or exhaust hose to the exhaust pipe of a clothes dryer or the like, the device having a tubular member of unitary construction with a first, female end portion and a second, male end portion; the first portion including magnetic material for magnetically engaging with a exhaust pipe of dryer, the second portion threadably engaged with an exhaust hose.

The literature is bereft of devices which enable quick and simplified coupling of a vent or exhaust hose to the exhaust pipe, for example, of a clothes dryer or the like. A variety of types of coupling means which function to fulfill the general purpose have been known in the art, one of which consists of a circular clamp adapted to attach exhaust hoses to clothes dryer exhaust pipes. One such type consists of a narrow metal band which fits around the exhaust hose and is tightened by turning a machine screw with a screwdriver. Another type is a circular spring clamp which also fits over the hose. The clamps are used to clamp the exhaust hose directly to the exhaust pipe.
It will be appreciated that the described clamps are difficult to use because dryers are manufactured with little working space around the exhaust pipe. Typically, the metallic exhaust pipe at the rear of a dryer terminates flush with the back of the dryer, and the dryer back has a shallow circular depression around the exhaust pipe. In order to use one of these clamps, it is necessary, first of all, that the clamp be put over the hose; then the hose must be placed over the end of the exhaust pipe. The exhaust hose fits over the pipe and, because there is little working room, it is hard to slide the hose onto the pipe to allow secure clamping. Furthermore, after the hose is on the pipe, a clamp must be moved into place and, in the first case cited, the machine screw must be tightened. However, a screwdriver cannot be aligned with the machine screw, because the clamp must be inside the plane of the dryer back in order to clamp the hose on the pipe. Thus, the screwdriver must be held off line to tighten the screw while holding the hose and clamp on the pipe.
As will be understood, the above described procedure is awkward and frequently results in less than secure clamping which allows the hose to slip off later when the dryer is vibrating during an operating cycle. The other type of clamp, that is, the spring clamp noted above must be gripped with a pair of pliers to hold it open while it is being moved into position so as to clamp the hose on the exhaust pipe. This is also a difficult feat which produces the same results as the first type of clamp described.
Other types of coupling devices known in the art are disclosed in U.S. Pat. Nos. 4,708,370 (Todd), 4,746,149 (Thompson), 4,887,852 (Hancock), 4,923,224 (Makris), and 5,109,756 (Barboza et al.).
Of particular note is U.S. Pat. No. 4,708,370, which is concerned with a recreational vehicle discharge pipe coupler and, in particular, discloses a device for coupling a drain pipe to a recreational vehicle discharge pipe fitting of a type having a terminal end portion with a plurality of locking pins extending radially outward from the periphery of the pipe fitting. As such, the female end of the coupling includes corresponding slots which secure about the locking pins by suitable rotation of the female end into mating position with terminal end portion of the discharge pipe. This coupler also utilizes a seal to prevent leakage of the liquid being drained.
U.S. Pat. No. 4,746,149 has a similar scheme to that of U.S. Pat. No. 4,708,370 involving a pair of slot and stud connected units for use between water conduits, such as a garden hose and faucet, an O-ring being provided to prevent escape of water between the units.
Whatever the merits in advantages of the prior devices described, none of them is capable of providing the features in advantages of the present invention. Manifestly, the devices described in the particular noted patents are dependent on having a discharge pipe or the like that is already provided with pins in this totally unavailing for use with a pipe lacking these.
Accordingly, it was a primary object of the present invention to provide a quick connect device that constitutes a simple economical, fast and secure means for coupling or attaching an exhaust hose to the exhaust pipe of a clothes dryer or the like, and also constitutes a means for detaching such hose.

Quick connect device with magnet for clothes dryer exhaust hose


A transmitter 43 transmits a write address (i.e., address translation packet before sending the first data packet of a command). A receiver 5, when receiving the address translation packet, executes address translation of a write address. The receiver 5 also preliminarily executes address translation in advance during inter-processor communication for reducing overhead of address translation in the destination processor that occurs for each page. The transmitter reports the total number of pages in advance for suppressing wasteful address translation subsequent to the last page.

This application claims the benefit of Japanese Patent Application No. 2001-170377 filed on Jun. 6, 2001, the contents of which are incorporated by reference.
The present invention relates to inter-processor communication systems and inter-processor communication methods used therefor and, more particularly, to an inter-processor communication method for a plurality of processors connected to a network, in which logical addresses are used as data read and write addresses.
In prior art inter-processor communication, the use of an erroneous data write address in a destination processor may causes system down condition in the destination processor. Accordingly, destination processor protection is provided by various means.
As an example, a received data buffer area is determined to permit writing of data only in this area in the inter-process communication (this method is hereinafter referred to as the first prior art technique). In this case, the receiver in the destination processor limits a write address to a physical address determined by the receiver, or to a region which is obtained by masking a physical address designated by the source processor with a mask bit pattern determined by the receiver.
As a different example, the source processor designates the write address not as a physical address but as a logical address (this method is hereinafter referred to as the second prior art technique). In this case, the receiver in the destination processor executes the translation of the write address from a logical address to a physical address. In this method, the physical address obtained by address translation in the receiver can be limited to be in a particular address range, and it is thus possible to protect the destination processor. However, if the designated write address is invalid, it would result in failure of the address translation.
In the above first prior art technique, because copying of data from the received data buffer area to a user's area is necessary, it causes degraded throughput performance and latency performance of the inter-processor communication. Accordingly, the second prior art technique method is frequently used, in which the write address is designated as a logical address.
In the second prior art technique, however, a means for translating the designated logical address to a physical address is necessary. This address translation is needed for each page, and the normal page size is 4 Kbytes. Therefore, transmission of a large quantity of data in the inter-processor communication requires a very large address translation table, which cannot be fully held in the receiver. Accordingly, the full address translation table is mounted in the main memory, and the receiver reads part of the table from the main memory as desired for the address translation.
This means that the address translation gives rise to access to the main memory, thus leading to overhead in the inter-processor communication. Particularly, when the main memory is accessed for address translation at the time of packet reception, the writing of packet data can be executed only after the address translation. Until the end of the address translation, therefore, the receiver cannot read data from the network. This has bad effects on other inter-processor communication as well. For improving the inter-processor communication performance, it is thus necessary to reduce such overhead.
The above prior art inter-processor communication has a problem that when the write address in the destination processor is designated as logical address in the parallel computer system, it is difficult to reduce or conceal the overhead in the address translation in the receiver.

Inter-processor communication systems and methods allowing for advance translation of logical addresses


A multimedia mail system and a method thereof generates a message including comments or notes on a background picture using voice and drawing data. The message is sent to a destination terminal using a mail system, and then is regenerated. The voice and drawing data of the received message is synchronized in the same time relation as that used for generation of the message.

1. Field of the Invention
The present invention relates to a multimedia mail system and a mail terminal device and a method thereof, and particularly to a multimedia mail system and a mail terminal device and a method thereof for generating a message using voice and drawing data to a destination terminal to which the message is transmitted, transmitting and receiving the generated message using a mail system, and regenerating the voice and drawing data of the received message in the same time relation between them as that used for the generation of the message.
2. Description of the Prior Art
In a conventional electronic mail system, mostly text information is handled. Even in a system which can handle media other than text such as a picture and/or voice, they are handled independently and asynchronously. For example, a picture and voice can be added to mail as different icons, respectively and a user can refer to them as required. Each medium is handled independently like this.
In these conventional mail systems, mostly text information is handled and even when media other than text such as a picture and/or voice media are handled, each medium is handled independently and asynchronously.

Image voice synchronized multimedia mail system and method thereof


A robot controller capable of automatically preparing a job program for a workpiece configured of a plurality of job elements is disclosed. A plurality of teaching programs for teaching the job for each job element making up the workpiece are stored in advance. Each teaching program has registered therein attribute information including the item number (identification information) and the sequence of application of the teaching program to each workpiece. The robot controller retrieves teaching programs having registered therein, as attribute information, the same item number as the input item number of the workpiece and prepares a main program such that the retrieved teaching programs are called sequentially as subprograms in accordance with the application sequence specified by the attribute information. Further, commands for moving to the job starting position and the job end position are added before and after the main program thereby to complete the main program. Based on the main program thus prepared, the robot controller controls the robot operation.

1. Field of the Invention
The present invention relates to a robot controller and a robot system wherein, in the case where a workpiece is configured of a plurality of work elements and a job pattern is determined for each work element, the workpiece is processed by a combination of job patterns for the work elements.
2. Description of the Related Art
A conventional method is known in which, in the case where a workpiece is configured of a plurality of elements and the job pattern for each element is determined, a job program for the workpiece is prepared by combining the programs of the job patterns for the work elements. In a robot for conducting a deburring job to deburr a product, for example, a teaching program for the deburring job is prepared for each part making up the product to be deburred, and the deburring job is conducted by calling the teaching program for each of parts making up the particular product from a main program.
In this known method, the main program forms a job program, which determines whether or not every one of the workpieces corresponds to one of the products already registered and, in the case where it is determined that the workpiece is one of the products already registered, sequentially calls a particular teaching program for each particular part (element) of the product required to carry out the job on the product, to thereby carry out the job on the product as a whole.
Note that no reference related to an invention wherein a job program on a product is prepared directly and automatically from teaching programs for elements of a workpiece, as the present invention described below, could be discovered.
In the conventional method wherein each teaching program for each of a plurality of elements making up a workpiece are combined to form a job program for the workpiece, preparation of a job program for a new workpiece (product) requires the operator to prepare and register a new teaching program necessary for the job or, alternatively, add a determination process for recognizing the new workpiece to the main program for forming a job program for a plurality of workpieces already registered and add an instruction to call the teaching program for each element required for the job to the branched portion of the main program. As a result, an error such as a command error of the branch instruction or a calling error of the teaching program to be called can occur. Further, the robot operation is required to be suspended during the adding process.

Robot system provided with robot controller


A semiconductor component and method of manufacture, including an insulated gate bipolar transistor (IGBT) (100, 200, 300, 400) that includes a semiconductor substrate (110, 210, 310, 410) having a first conductivity type and buried semiconductor region (115, 215, 315, 415) having a second conductivity type located above the semiconductor substrate. The IGBT further includes a first semiconductor region (120, 220, 320, 420) having the first conductivity type located above the buried semiconductor region, a second semiconductor region (130, 230, 330, 430) having the first conductivity type located above the first semiconductor region, a third semiconductor region (140, 240, 340, 440) having the second conductivity type located above the first semiconductor region, an emitter (150, 250, 350, 450) having the first conductivity type disposed in the third semiconductor region, and a collector (170, 270, 370, 470) having the first conductivity type disposed in the third semiconductor region. In a particular embodiment, the third semiconductor region and the buried semiconductor region deplete the first semiconductor region in response to a reverse bias applied between the second semiconductor region and the third semiconductor region.

Power devices are electronic components designed to be tolerant of the high currents and voltages that are present in power applications such as motion controlled air bag deployment and automotive fuel injector drivers. The power lateral double-diffused metal-oxide-semiconductor (LDMOS) field-effect-transistor (FET) device, referred to herein as a power LDMOS device, is becoming increasingly popular for such power applications. As power technologies develop, power applications require smaller and smaller power devices with a high breakdown voltage.
Many applications for power LDMOS devices require the inclusion of a series connected reverse diode on certain output nodes in order to realize voltage blocking capability in both positive and negative directions. When the application cannot tolerate the LDMOS body diode, such as when there is a regular output with no reverse path from the output to the input, a discrete diode in series with the LDMOS or two back-to-back LDMOS structures are used to achieve high breakdown voltage in both directions. There exists a problem with device mismatch when multiple LDMOS devices are required or an LDMOS-diode structure is required. In these types of devices a certain percentage of mismatch is expected. Insulated gate bipolar transistors (IGBTs) provide for an alternative structure.
IGBTs are designed for power applications and combine metal-oxide-semiconductor (MOS) gate control and a bipolar current flow mechanism. An IGBT incorporates features of both a metal-oxide-semiconductor field effect transistor (MOSFET) and a bipolar junction transistor (BJT). IGBTs have higher current density than MOSFETs and faster switching characteristics than BJTs. IGBTs are the primary choice today for high-power (>10 kW), low to medium frequency (up to 30 kHz) applications.
IGBT devices feature high current/high voltage operation and high input impedance at the same time. Replacing power LDMOS multi-structures with an insulated gate bipolar transistor (IGBT) provides significant savings in the required device area. That is, IGBT devices are significantly smaller than an LDMOS-diode structure or a LDMOS-LDMOS structure because the on-resistance in an IGBT is lower.
In addition, conventional LDMOS devices suffer from minority carrier current in to the substrate which can harm the surrounding devices. IGBT device structures are less susceptible to such substrate injection. IGBTs typically, do not have the same reverse recovery time associated with a standard LDMOS body diode.
Accordingly, it is desirable to provide a high voltage IGBT structure for silicon bulk based (non silicon-on-insulator (SOI)) power integrated circuits (ICs). Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.

Semiconductor device and method of manufacture


A hinge for a folding ladder including a hinge latch movable between a locked position and an unlocked position disposed within a hinge latch cavity. The hinge latch includes a first locking portion protruding therefrom, an elongated slot formed configured to slidingly receive a hinge shaft, a first opening configured to receive a first biasing member, and a second opening configured to receive a locking member. Rotational movement of one hinge casing relative to another hinge casing is prevented by engagement of the first locking portion and locking member with a respective one of the first opening and second opening.

Examples of attic ladders or "disappearing stairways" are shown, for example, in U.S. Pat. Nos. 2,649,237 and 2,852,176. These ladders normally fold and retract upwardly into a frame secured between adjacent joists of the attic, and the folded ladder is covered by a door which normally extends substantially flush with the finished ceiling of the room in which the ladder is mounted. Attic ladders thus take up no floor space except when actually extended and are also inexpensive to construct, as compared with fixed stairways typically constructed on-site.
U.S. Pat. No. 4,281,743 issued to Fuller on Aug. 4, 1981 shows another conventional attic ladder. As shown in FIG. 1 attic ladder 11 includes an outside frame 12 which is mounted between adjacent floor joists 13 of the attic floor 14. Cross braces 15 are mounted between a pair of adjacent floor joists 13 to provide end support for the frame 12 of the disappearing stairway. Ladder 11 is mounted in the ceiling by securing frame 12 to the joists 13 and the cross braces 15. A cover panel 16 forms part of ladder 11 and is hinged to the outer frame 12, so that the door becomes substantially flush with the ceiling 17 when the ladder 11 is folded. A first ladder portion 17 is affixed to the inner face of cover panel 16 and a second ladder portion 18 is pivotally hinged to the first ladder portion so as to be unfolded or folded when the ladder is opened or closed. While commercially available attic ladders or disappearing stairways typically come in a number of sizes, most come in several standard widths and lengths adaptable to fit conventional constructions.
U.S. Pat. No. 4,541,508 issued to Lundh on Sep. 17, 1985 shows yet another conventional attic ladder. In FIG. 2, a foldable ladder is shown to consist of a lower section 11, a central section 12 and an upper section 13. The central section 12 is hingedly connected to the two remaining sections 11,13 by a hinge so that the central section 12 and the lower section 11 can be folded up on the upper section 13. Upper section 13 is hingedly attached to a frame 14 by hinges 15, with the folding down movement of the upper ladder section 13 being limited by a pair of toggle joints 16,17, attached to the upper ladder section and to the frame 14. Toggle joints 16,17 are rigidly connected to each other at the lower arms by means of an axle 18 extending in parallel with the rungs of the ladder and are attached to the axle outside the side rails of the ladder. The ladder is spring-biased to a closed position by a gas spring 19 connected at one end to an outside of one side rail and connected at its other end, via piston rod 19a, to moment arm 18a, which is rigidly connected to the axle 18 at such an angle that a maximum moment is generated when the door is almost entirely closed. When the point of connection between the gas spring 19 and the moment arm 18a has passed the line for moment centre (i.e. the connecting line between the attachment of the gas spring 19 to the ladder 13 and the axle 18, which passing takes place when the door is opened entirely), the gas spring 19 actuates the door so that it is locked in folded-down position, which is necessary because the "weight" of the door decreases as soon as the ladder sections are folded out.
However, despite the above-noted improvements to the attic ladder and disappearing stairway art, additional improvements can be realized in the structure of the attic ladder, particularly the hinges.


An ohmic contact to a III-V semiconductor material is fabricated. First, a III-V semiconductor material is provided. Source/drain regions are then formed in the III-V semiconductor material. On the III-V semiconductor material, a contact system is formed which is dry etchable using reactive ions such as chlorine or fluorine and substantially free of arsenic. Subsequently, a portion of the contact system is dry etched using reactive ions such as chlorine or fluorine to leave a portion of the contact system remaining on the source/drain regions. Then, the III-V semiconductor material and the contact system are annealed in an atmosphere substantially free of arsenic at a temperature at which at least a part of the contact system is alloyed with the source/drain regions to form an ohmic contact with the source/drain regions of the III-V semiconductor material.

This invention relates, in general, to a method of forming ohmic contacts to III-V semiconductor materials, including, but not limited to, a thermally stable ohmic contact for III-V semiconductor materials.
Ohmic contact is made to III-V semiconductor materials with various contact systems. A nickel, germanium and gold (Ni/Ge/Au) or a gold, zinc and gold (Au/Zn/Au) system has been used in the past. These gold containing systems require the use of photolithography lift-off techniques, because gold is not dry etchable (etchable with reactive ions, rather than wet chemicals) using reactive ions such as chlorine (Cl.sup.-) or fluorine (F.sup.-). It would be desirable to use dry etching in processing the contact system in order to be able to use a self-aligned gate fabrication process and to scale down the size of the semiconductor devices.
Another contact system to III-V semiconductor materials used in the past is comprised of palladium and germanium (Pd/Ge). This system also has its disadvantages because the contact resistivity is not thermally stable at temperatures above 500.degree. C. Therefore if the contact system is exposed to such temperatures, the contact resistance increases, and degrades the gain of the transistor. In certain steps of fabricating semiconductor devices in III-V semiconductor material, it is necessary to expose the device to temperatures above 500.degree. C., therefore it would be desirable to have a contact system which is thermally stable above that temperature.
Yet another contact system to III-V semiconductor materials used in the past is comprised of germanium, molybdenum and tungsten (Ge/Mo/W). This contact system is dry etchable and thermally stable, however, it exhibits nonohmic behavior. To make this system ohmic, arsenic must be used in the annealing ambient or must be introduced into Ge directly (which forms Ge(As)/Mo/W). The use of arsenic in these processes is highly undesirable due to the toxicity of arsenic. Thus, it is necessary to come up with an ohmic contact to III-V semiconductor materials which does not use arsenic in the process of fabricating it.

Method of forming an ohmic contact to III-V semiconductor materials


A graft fixation device such as for use in holes drilled into the intercondylar notch of the femur for a bone-patella tendon-bone constructs, for immediate and secure fixation of both ends of a graft. The device comprises a wedge shaped shim constructed of a hard (preferably metal) biologically inert material, which is wedged in between the graft and the formed tunnel in which the graft is positioned. One side of the shim is arcuate and adapted to be from one third to one half a complete circle circumference (adapted to fit into holes of varying circumferences). The shim is either wedge shaped or formed with central aperture for insertion of an expander such as a screw, to snug up and securely wedge an adjacent graft within a bone hole. The shim does not entail bone damage such as occurs with screw fixation devices, and can be adjusted to the correct and secure holding pressure. The shim is also removable and/or replaceable for different sizes as required.

Reconstruction of the anterior and posterior cruciate ligaments is an increasingly popular orthopedic operation resulting from an increasingly active lifestyle of the populace. Strenuous physical activities involved in this type of lifestyle may cause injuries which result in instability of the knee which must be reconstructed, generally in the form of the aforementioned ligament reconstruction procedures. In addition to correcting knee instability, ligament reconstruction may also provide a secondary beneficial effect of possibly reducing the incidence of secondary arthritis or secondary meniscal tears.
Of the general ligament reconstruction procedures, the most popular is that of "bone-patella tendon-bone". In this procedure or technique, a central 9 or 10 mm portion of the patella tendon is harvested with its attachment onto the patella and tibial tubercle, with a plug of bone which is usually about 25 mm in length and about 9 or 10 mm in width. The graft itself may be cylindrical or trapezoidal in shape depending on surgeon preference.
In the procedure, a hole is drilled into the intercondylar notch of the femur on the lateral side just above the "over-the-top" position. This follows formation of a hole in the tibia which extends from the anteromedial surface into the center of the tibial articular surface, about 7 mm from the posterior cruciate ligament. The bone-patella tendon-bone construct is threaded up through the tibia into the knee and then pulled into the femoral hole. In order for the patient to immediately begin a range of motion program, it is desirable, if not necessary, to provide immediate and secure fixation for both ends of the grafts, whereby the patient can move the knee and begin early bearing exercises.
Several fixation devices have been developed and are available in order to provide the requisite secure fixation. The most popular of such devices is the "interference" screw, with a biologically inert screw being inserted in the femoral hole at the interface between the bone plug of the graft and the host femoral bone. The threads of the screw bite into the graft and the host bone and hold the graft firmly against the bone. The screw can be inserted at the femoral side and the tibial side, but the tibial side is more problematic, particularly if the graft is too short or too long. Accordingly, on the tibial side, the graft is often "posted" via sutures attached to the graft over a cancellous screw and washer, inserted into the tibial bone at some distance away from the previously drilled tibial hole.
There are however, problems and shortcomings which are associated with the "interference" screw fixation procedure. Foremost of these problems is an inherent one related to the operation of the fixation screw. The graft or the posterior cruciate ligament may be damaged by the very insertion of the interference screw, generally as a result of the threads which must bite into the bone for operable fixation. Furthermore, the screw head, because of its close juxtaposition, may impinge on the graft, thereby contributing to further stretching and/or rupture thereof. Size of the screw is also of critical importance since an oversized screw can crush the graft and an undersized screw will provide inadequate fixation. Use of a screw of an incorrect size often will also disrupt the integrity of the fixation site or graft, thereby necessitating use of a different fixation means. This is particularly true on the femoral side and an adjunct technique then becomes necessary. On the tibial side, problems arise with posting such as loosening of the graft and difficulty in tying sutures over the post with adequate tension in order to keep the graft appropriately taut. Often the graft will loosen or the sutures will loosen or the sutures may be cut or severed by the screw threads. If a change is needed, the screw must be removed and another must be reinserted, which can further compromise the graft.


A nonaqueous electrolyte secondary battery according to an embodiment of the present invention includes an electrode assembly, a nonaqueous electrolyte, and a container. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The negative electrode is opposed to the positive electrode. The separator is disposed between the positive electrode and the negative electrode. The container houses the electrode assembly and the nonaqueous electrolyte. The container has a positive electrode terminal and a negative electrode terminal. The positive electrode terminal is electrically connected to the positive electrode. The negative electrode terminal is electrically connected to the negative electrode. The container further includes a short-circuiting mechanism that short-circuits the positive electrode terminal and the negative electrode terminal if the internal pressure rises. The nonaqueous electrolyte contains lithium bis(oxalato)borate (LiBOB).

In recent years, there have been various endeavors to use nonaqueous electrolyte secondary batteries in, for example, electric vehicles, hybrid cars, and the like. In such applications, it is necessary to ensure safety in cases where, if the nonaqueous electrolyte secondary battery is subjected to impact, excessive heat may be generated in the interior and the electrolyte may break down, with the result that the interior pressure rises. Therefore, JP-A-2011-18645 proposes the provision of a pressure-sensitive forced short-circuiting mechanism in nonaqueous electrolyte secondary batteries.
In a nonaqueous electrolyte secondary battery, the pressure inside the container increases due to deterioration. Therefore, when there is a prolonged use period, the forced short-circuiting mechanism may activate erroneously during the regular use.

Nonaqueous electrolyte secondary battery


The light control system includes command means (640) for outputting a command signal indicating a direction of rotation of the light control means (300), detection means (630) for detecting electromotive force generated in a coil (510), switch means (610) for connecting the coil to drive means (500, 302, 620) in a driving state in which current is supplied to the coil and connecting the coil to the detection means in a non-driving state in which electromotive force generated in the coil is detected, determination means (660) for determining a rotational state of a rotary shaft member (302), based on an output signal output from the detection means, and control means (650) for outputting a command for causing the drive means to output a drive signal, based on an output signal output from the determination means.

1. Field of the Invention
The present invention relates to alight control system.
2. Description of the Related Art
With enhancement of image quality of small-size image pickup devices such as mobile devices having image pickup function and micro video scopes in recent years, there are increasing needs for optical elements such as lenses, stops, and optical filters to shift from fixed focal length lenses, fixed aperture stops, filters having fixed characteristics used in the past to adjustable focus lenses, variable stops, and variable characteristic filters. Moreover, many light control systems have been developed as means for reducing the size of optical components used in small-size image pickup devices.
Japanese Patent Application Laid-open Publication No. H10-20360 discloses a light quantity control apparatus as an example of such light control systems. FIG. 5 is an exploded perspective view showing the overall construction of a conventional light quantity control apparatus.
The light quantity control apparatus shown in FIG. 5 has a printed board having a multi-layer structure and a coil having a film core made of a material having high magnetic permeability provided on the printed board. A cylindrical rotor 920 magnetized to have at least two magnetic poles is fitted to the coil part 925 having the above-described structure, and a stop blade 915 used to control the transmitted light quantity is fixedly attached to the rotor 920. The stop blade 915 is arranged between upper and lower plates 910, 911 and shifted in the gap between the upper and lower plates 910, 911 by the coil formed on the printed board.


An exercise boot comprises a foot receiving member and a spring member positioned under the foot receiving member. The foot receiving member is formed of a unitary flexible piece of material which has integrally joined left and right symmetrical portions and which has been brought together. The spring member comprises identical top and bottom arcuate layers connected in an opposed relationship by a resilient strap and each defining a central slot. The symmetrical portions are provided with base portions which form a sole in the foot receiving member for supporting a wearer's foot and provided with hooks for engaging the slot of the top arcuate layer and thus secure the foot receiving member to the spring member while retaining the left and right symmetrical portions together in a boot configuration and in a way that most of the springiness of the top arcuate member is retained where it is connected to the foot receiving member. A ground engaging sole which defines an interrupted rib inserted in the slot of the bottom arcuate layer is further secured thereto with a pair of bands.

1. Field of invention
The present invention relates to an exercise boot and, more particularly, to a foot receiving member which has a spring member assembled at the bottom thereof.
2. Description of Prior Art
U.S. Pat. Nos. 4,492,374 issued on Jan. 8, 1985 to Lekhtman et al. and No. 5,205,789 issued on Apr. 27, 1993 to Lekhtman each disclose a sporting and exercising boot which comprises a foot receiving member and an oval shaped spring member attached to the bottom of the foot receiving member. The spring member includes top and bottom arched layers which are joined together at corresponding ends thereof by a spring rate and weight adjustment mechanism extending between the top and bottom arched members.
The oval shaped spring member described in U.S. Pat. No. 4,492,374 is permanently attached to the foot receiving member. It is noted that the nature of the attachment of the top and bottom arched layers does not allow for the oval shaped spring member to disassemble under condition of extraordinary lateral force.
The top arched layer of the oval shaped spring member disclosed in U.S. Pat. No. 5,205,789 is detachably fastened to the sole of the foot receiving member by two screws which extend through openings defined in the top arched layer and into the foot receiving member. The spring member is provided with a sole which is detachably mounted to the bottom surface of the bottom arched layer by screws; alternatively, the sole can be attached to the bottom arched layer by inserting the ends of the sole into respective pockets defined near the ends of the bottom arcuate layer.


An electrooptical apparatus includes a plurality of scanning lines, a plurality of signal lines, and electrooptical devices, each being placed at an intersection of each of the scanning lines and each of the signal lines. The electrooptical apparatus is driven according to the amount of drive current supplied to the electrooptical devices. The electrooptical apparatus includes a brightness detection unit to detect the brightness of the electrooptical devices, and a drive current amount adjusting unit to adjust the amount of drive current based on the detected brightness result obtained by the brightness detection unit in order to correct for the brightness of the electrooptical devices.

1. Field of Invention
The present invention relates to an electro-optical device, a driving method thereof, and an electronic apparatus.
2. Description of Related Art
In related art organic EL (electroluminescent) display devices, for example, the degradation of the luminous brightness of organic EL elements of the organic EL display devices over time is much more rapid than that of inorganic EL display devices. That is, as the lighting time accumulates, the reduction in brightness becomes noticeable. Specifically, the life of the inorganic EL display devices is over 100,000 hours, during which the reduction in brightness is hardly exhibited. In contrast, in the organic EL display devices, the lighting time with a luminance of, for example, 300 cd/m2 is up to approximately 10,000 hours.
Accordingly, this drawback can be addressed or overcome by enhancing the manufacturing process, as disclosed in Japanese Unexamined Patent Application Publication No. 11-154596, and Japanese Unexamined Patent Application Publication No. 11-214257.

Electro-optical device, driving method thereof, and electronic apparatus


An ion implantation process simulation device includes a Dual Pearson data extracting unit for generating a Dual Pearson data table from ion implantation profile data, a Dual Pearson data for interpolation obtaining unit for obtaining a parameter for use in the interpolation and extrapolation of a dose coefficient from the Dual Pearson data table, a dose coefficient interpolating/extrapolating unit for expressing an ion implantation profile by linear connection of two functions respectively representing an amorphous component and a channeling component, as well as using a dose-independent moment parameter and a coefficient of linear connection dependent on dose to interpolate and extrapolate a logarithmic value of a channeling component dose coefficient with respect to logarithmic values of all dose values, and a simulation result outputting unit for outputting a simulation result.

1. Field of the Invention
The present invention relates to an ion implantation process simulation device realizing accurate interpolation and extrapolation of ion implantation profiles including tails in ion implantation process simulation for a semiconductor device, and a simulation method therefor.
2. Description of the Related Art
A manufacturing process of semiconductor devices including LSI includes a step of implanting impurity ions as dopant into a semiconductor substrate by an ion implantation technique and diffusing and activating them through a thermal treatment. It is well-known that an impurity distribution obtained in this step accounts for the considerable change in a threshold voltage Vt, an ON-state current of a transistor and other electrical characteristics parameters. In recent years, in particular, for reducing a semiconductor in size to achieve high density large capacity and high speed, designing a transistor with shallower junctions has been gaining more importance. More specifically, demanded is not only accurate control of a peak concentration of impurities but also accurate adjustment of position of the tail of an ion implantation profile.
In order to meet this demand, ion implantation process simulation using a computer is adopted. This is a method of predicting and calculating various ion implantation profiles for use in manufacturing semiconductor devices by using predetermined models and algorithms on a computer. Use of ion implantation process simulation largely contributes to the reduction in the number of experimental steps for improving element characteristics of a semiconductor device and to the improvement in efficiency of designing work.
In simulating ion implantation profiles, in general, ion implantation profiles are described using a Gaussian or Pearson function which can obtain satisfactory enough approximation when crystals are amorphous. At that time, since ion implantation into a semiconductor crystal substrate reflects crystallinity of the substrate, profiles will vary depending on crystal orientation of the substrate and an ion implantation angle, that is, the channeling phenomenon will occur. The channeling phenomenon tends to decrease with an increase in dose value. This is because crystals become amorphous as a dose value is increased. Profiles of ion implantation into a semiconductor crystal substrate can not therefore be described by using a simple Gaussian or Pearson function but can be described by using a plurality of functions.
A technique of describing a profile of ion implantation into a semiconductor crystal substrate by using a function and simulating the same is disclosed, for example, in "An Improved Approach to Accurately Model Shallow B and BF.sub.2 Implants in Silicon" (Al F. Tasch, H. Shin, and C. Park; J. Electrochem. Soc., Vol. 136, No. 3, March 1989, pp. 810-814; The Electrochemical Society, Inc.). The literature recites a method of more accurately simulating experimental profiles of as-implanted ion impurities. The experimental profiles are results of measurement obtained by the SIMS (Secondary Ion Mass Spectrometry) method. SIMS is a well-known method of irradiating a surface region of a semiconductor with a primary ion such as an oxygen ion or a cesium ion to generate a secondary ion and conducting mass analysis of the secondary ion to measure an impurity distribution. The experimentally obtained ion implantation profile is expressed using two Pearson functions which represent an amorphous component and a channeling component, respectively. The ion implantation profile N(x) is described as a sum of the two components as shown in the following equation (1). EQU N(x)=D.sub.main f.sub.main (x)+D.sub.sub f.sub.sub (x) (1)
where a main peak amorphous component function f.sub.main (x) and a subsidiary peak channeling component function f.sub.sub (x) are normalized functions not dependent on a dose value, while D.sub.main represents a main peak amorphous component dose coefficient and D.sub.sub represents a subsidiary peak channeling component dose coefficient. A total dose D.sub.T of the ion implantation profile N(x) is described as a sum of coefficients of the amorphous component dose and the channeling component dose as shown in the following equation (2). ##EQU1## The Pearson function used here is described using four kinds of moment parameters, projected range Rp, standard deviation .DELTA.Rp, skewness .gamma. and kurtosis .beta..
In the following, description will be made of a conventional ion implantation process simulation method of obtaining an ion implantation profile for a prescribed dose by interpolation, with reference to a flow chart of FIG. 6. With reference to FIG. 6, first, from table data of ion implantation profiles for several dose values, extract moment parameters, projected range Rp, standard deviation .DELTA.Rp, skewness .gamma. and kurtosis .beta. in two normalized functions respectively representing the amorphous component and the channeling component (moment parameters of a Dual Pearson function), an amorphous component dose coefficient and a channeling component dose coefficient (Step 601). As a result, a Dual Pearson data table is prepared. Next, select parameters for doses at two points most neighboring to an arbitrary dose from the Dual Pearson data table (Step 602). Next, out of the selected parameters, linearly interpolate the dose-dependent amorphous component dose coefficient and channeling component dose efficient with respect to dose (Step 603).
More specifically, first, use SIMS experimental profile data at a plurality of dose points to extract a functional parameter value and a ratio of the coefficients of an amorphous component dose at a main peak to a total dose, D.sub.main /D.sub.T. The functional parameter and the ratio of the coefficients of an amorphous component dose at a main peak to a total dose are recited for boron and BF.sub.2 in the above-described literature.
FIG. 7 is a diagram showing a dose dependency as a parameter to be interpolated. In FIG. 7, the abscissa represents a dose value, the ordinate represents a main peak amorphous component dose ratio and the polygonal line represents a dose dependency of a main peak amorphous component dose ratio. As illustrated in FIG. 7, the number of dose points of the experimental data shown in the diagram are five, not so many. Ratios of the coefficients of a main peak amorphous component dose to the total dose at the other doses need to be interpolated for all the doses. When moment data and ratios of coefficients of a main peak amorphous component dose to the total dose (D.sub.main, i /D.sub.T, i) and (D.sub.main, i+1 /D.sub.T, i+1) of the ion implantation profile at dose values D.sub.T, i and D.sub.T, i+1 of two points for the interpolation or extrapolation with respect to an arbitrary dose value D.sub.T, a are given, linear interpolation by a conventional simulation method will result in describing a ratio of each coefficient of the amorphous component dose and the channel component dose to the total dose at the arbitrary dose value D.sub.T, a, that is, (D.sub.main, a /D.sub.T, a) and (D.sub.sub, a /D.sub.T, a), as shown in the following equation (3). ##EQU2##
According to the above-described conventional ion implantation process simulation method, however, when profiles N.sub.i (x) and N.sub.i+1 (x) at two dose points D.sub.T, i and D.sub.T, i+1 (D.sub.T, i <D.sub.T, i+1) satisfy the relationship N.sub.i (x)<N.sub.i+1 (x), inversion might occur between the intensity of a profile N.sub.a (x) obtained by linear interpolation with respect to a dose point D.sub.T, a located between the two points and the intensity of the profile N.sub.i+1 (x). Shown in FIG. 8 as an example are calculation results obtained by a standard process simulator SUPREM-3 which is widely used at present. With reference to FIG. 8, the curve CP3 of the profile N.sub.a (x) obtained by linear interpolation between the profile curves CP2 and CP4 according to the above-described conventional linear interpolation method crosses with the profile curves CP1 and CP2 for larger doses at the tail. In other words, the profile curve CP3 is undesirably shown to have a higher concentration than those of the profile curves CP1 and CP2.
Based on this result, it is possible to conduct interpolation with respect to a logarithmic value of a dose on the abscissa according to the following equation (4). ##EQU3## While the interpolation results obtained in this case are slightly improved as compared with those of FIG. 8, undesirable inversion of the intensity at the tail can not be avoided.
As described in the foregoing, conventional ion implantation process simulation methods have a drawback that in simulation of an impurity profile for junction depth, undesirable interpolation is caused at a tail of the ion implantation profile to prevent acquisition of accurate simulation results.

Ion implantation process simulation device realizing accurate interpolation of ion implantation profiles and simulation method therefor


A concentrated-winding type stator coil unit for a rotary electric machine is provided with a stator core having a core back and teeth protruding from the core back. Plural coils are wound around the teeth respectively. Each coil is composed of, for example, a first layered coil formed by winding a coil wire in a layer around each tooth to form plural turns arranged in parallel on each tooth and a second layered coil formed by winding the coil wire in a layer to from plural turns around the first layered coil wound around each tooth. The last turn of the first layered coil continues to the first turn of the second layered coil. Both ends of the coil wire are located at and on a base potion of each of the teeth as a winding-start end and a winding-finish end of each of the coils.

1. Technical Field
The present invention relates to a stator coil unit for rotary electric machines such as electric motors and electric generators, and in particular, to a concentrated-winding type stator coil unit for the rotary electric machines.
2. Related Art
In a rotary electric machine, a stator is required to convert electric energy into kinetic energy or vise versa. At present, there have been various types of stators.
One type of stator has coils each wound around each of teeth (serving as magnetic poles) of a stator core in a concentrated manner and the wound coils (frequently referred to as tooth coils) are, phase by phase, mutually connected with each other to form each phase coil. Such a stator is called "concentrated-winding type stator." In winding a coil around each tooth to manufacture the concentrated-winding type stator, it is general to employ an assembled type of core, in which partial cores divided teeth by teeth are assembled to form a stator core.
If the stator core is designed as an outer rotor type of stator, a cylindrical stator core can be used, in which a coil is directly wound around each of the teeth protruding from the outer circumferential surface of a cylindrical stator core. Alternatively, an inner rotor type of stator might be used, in which a coil is directly wound around each of the teeth protruding from the inner circumferential surface of a cylindrical stator core. A Japanese patent laid-open publication No. 2001-25198 (reference 1) discloses this kind of concentrated-winding type stator.
As shown by the reference 1, in the concentrated-winding type stator, the tooth coil is wound around each tooth or each bobbin loaded on each tooth by a necessary number of turns. Like the normal coil winding, the coil is wound in turn in the axial direction of each tooth. As a result, mutually neighboring two turns, which are electrically connected with each other, can be wound at the highest density if the two turns are placed without a gap along the circumferential surface along its axial direction.
Like the normal coil winding, the wound coil starts at one end of each tooth in a radial direction thereof (normally, the base portion of each tooth) and reaches the tip portion of the teeth, so that the first layer of coil (hereinafter called "the first layered coil" as well) is constituted. The coil is then wound on the first layer coil such that the coil returns from the tip portion of each tooth to the base portion thereof, thus constituting the second layer of coil (hereinafter called "the second layered coil" as well). Likewise, the coil is wound on the second layered coil to form the third layered coil, thereby providing a high-density winding manner. The first, second and third layered coils and subsequent coils are generalized as "layered coils."
A Japanese patent laid-open publication No. 2001-186703 (reference 2) discloses two winding ways: one is that the beginning end of a tooth coil is placed at the basis portion (or the tip portion) of each tooth and the dead end of the tooth coil is placed at the tip portion (or the base portion), while the other way is that both the beginning and dead ends of a tooth coil are placed at the tip portion of each tooth. In this case, the number of layered coils is two, so that the two-layered coil is formed.
However, as stated above, crossover wires are used to mutually and sequentially connect the tooth coils located at predetermined pitches in the circumferential direction of a stator, with the result that each phase coil is configured. Accordingly, in the two-layered coil type of tooth coil taught by the reference 2, it is probable that both the beginning and dead ends of the tooth coil be localized at the tip. In such a localized location of both the ends, the crossover wires are located to almost touch the surface of the rotor, if the crossover wires are bridged to be the shortest. It has been found that this bridging location has various drawbacks. For example, vibration will cause the wire to touch the rotor and the wire obstructs fitting work of the rotor into a machine.
One solution to those drawbacks is provided by a particular connection manner, in which the crossover wire is drawn from the dead end located at the tip portion of each tooth to the base portion thereof in the radial direction of a rotor (in the case of the inner rotor type, to each radial outside end), is made to extend along the rotor surface to reach the next tooth belonging to the same phase, and is made to extend along the tooth to arrive at the tip portion thereof. The crossover wire, which has been at the tip portion of the next tooth, is connected to the beginning end of a tooth coil wound around the tooth and located at the tip portion. However, this kind of connection manner will cause the crossover wire to be longer between teeth, thus leading to an increase in power loss on account of resistance across the stator coil.
In addition, the winding technique taught by the reference 2 involves a folded portion, at which the wire is folded from the first layer coil to the second layered coil so as to allow both of the last turn of the first layered coil and the first turn of the second layered coil to be stacked one on the other. At this folded portion, the wound coil becomes thicker and protrudes from the surface of a tooth in the radial direction thereof by an amount corresponding to the thickness (of diameter) of the wire. This protrusion of the wound coil will reduce a slot lamination factor. That is, to make it possible to wind one pair of tooth coils around two teeth respectively located at both ends of one slot, an excessive space should be secured to accommodate the respective folded portions therein due to the protrusions of the folded coil in the radial direction. Therefore, of a circumferential width of each slot, a space corresponding to a width which is two times the thickness of the wire becomes useless, reducing the slot lamination factor.
Although the above has been explained on condition that the tooth coils are mutually connected in series phase by phase, the foregoing difficulties are true of a stator coil unit in which the tooth coils are mutually connected in parallel phase by phase with the use of crossover bus bars.

Concentrated-winding type stator coil unit for rotary electric machine


A gas cooled dynamoelectric machine is provided that is comprised of a rotor, a rotor winding comprising axially extending coils and concentric endwindings, and a plurality of spaceblocks located between adjacent endwindings thereby to define a plurality of cavities, each bounded by adjacent spaceblocks and adjacent endwindings. To enhance the heat transfer rate from the copper end turns of the field endwinding region, at least one scoop structure is provided adjacent the radially inner end of a cavity facing surface of at least one spaceblock for intercepting and redirecting coolant flow into the respective cavity. The spaceblock itself may have curved upstream and/or downstream surfaces for facilitating circulating coolant flow.

The present invention relates to a structure for enhanced cooling of generator rotors by directing a greater volume of coolant flow into rotating endwinding cavities for increasing heat transfer therewithin.
The power output rating of dynamoelectric machines, such as large turbo-generators, is often limited by the ability to provide additional current through the rotor field winding because of temperature limitations imposed on the electrical conductor insulation. Therefore, effective cooling of the rotor winding contributes directly to the output capability of the machine. This is especially true of the rotor end region, where direct, forced cooling is difficult and expensive due to the typical construction of these machines. As prevailing market trends require higher efficiency and higher reliability in lower cost, higher-power density generators, cooling the rotor end region becomes a limiting factor.
Turbo-generator rotors typically consist of concentric rectangular coils mounted in slots in a rotor. The end portions of the coils (commonly referred to as endwindings), which are beyond the support of the main rotor body, are typically supported against rotational forces by a retaining ring (see FIG. 1). Support blocks are placed intermittently between the concentric coil endwindings to maintain relative position and to add mechanical stability for axial loads, such as thermal loads (see FIG. 2). Additionally, the copper coils are constrained radially by the retaining ring on their outer radius, which counteracts centrifugal forces. The presence of the spaceblocks and retaining ring results in a number of coolant regions exposed to the copper coils. The primary coolant path is axial, between the spindle and the bottom of the endwindings. Also, discrete cavities are formed between coils by the bounding surfaces of the coils, blocks and the inner surface of the retaining ring structure. The endwindings are exposed to coolant that is driven by rotational forces from radially below the endwindings into these cavities (see FIG. 3). This heat transfer tends to be low. This is because according to computed flow pathlines in a single rotating end winding cavity from a computational fluid dynamic analysis, the coolant flow enters the cavity, traverses through a primary circulation and exits the cavity. Typically, the circulation results in low heat transfer coefficients especially near the center of the cavity. Thus, while this is a means for heat removal in the endwindings, it is relatively inefficient.
Various schemes have been used to route additional cooling gas through the rotor end region. All of these cooling schemes rely on either (1) making cooling passages directly in the copper conductors by machining grooves or forming channels in the conductors, and then pumping the gas to some other region of the machine, and/or (2) creating regions of relatively higher and lower pressures with the addition of baffles, flow channels and pumping elements to force the cooling gas to pass over the conductor surfaces.
Some systems penetrate the highly stressed rotor retaining ring with radial holes to allow cooling gas to be pumped directly alongside the rotor endwindings and discharged into the air gap, although such systems can have only limited usefulness due to the high mechanical stress and fatigue life considerations relating to the retaining ring.
If the conventional forced rotor end cooling schemes are used, considerable complexity and cost are added to rotor construction. For example, directly cooled conductors must be machined or fabricated to form the cooling passages. In addition, an exit manifold must be provided to discharge the gas somewhere in the rotor. The forced cooling schemes require the rotor end region to be divided into separate pressure zones, with the addition of numerous baffles, flow channels and pumping elements which again add complexity and cost.
If none of these forced or direct cooling schemes are used, then the rotor endwindings are cooled passively. Passive cooling relies on the centrifugal and rotational forces of the rotor to circulate gas in the blind, dead-end cavities formed between concentric rotor windings. Passive cooling of rotor endwindings is sometimes also called xe2x80x9cfree convectionxe2x80x9d cooling.
Passive cooling provides the advantage of minimum complexity and cost, although heat removal capability is diminished when compared with the active systems of direct and forced cooling. Any cooling gas entering the cavities between concentric rotor windings must exit through the same opening since these cavities are otherwise enclosedxe2x80x94the four xe2x80x9cside wallsxe2x80x9d of a typical cavity are formed by the concentric conductors and the insulating blocks that separate them, with the xe2x80x9cbottomxe2x80x9d (radially outward) wall formed by the retaining ring that supports the endwindings against rotation. Cooling gas enters from the annular space between the conductors and the rotor spindle. Heat removal is thus limited by the low circulation velocity of the gas in the cavity and the limited amount of the gas that can enter and leave these spaces.
In typical configurations, the cooling gas in the end region has not yet been fully accelerated to rotor speed, that is, the cooling gas is rotating at part rotor speed. As the fluid is driven into a cavity by means of the relative velocity impact between the rotor and the fluid, the heat transfer coefficient is typically highest near the spaceblock that is downstream relative to the flow directionxe2x80x94where the fluid enters with high momentum and where the fluid coolant is coldest. The heat transfer coefficient is also typically high around the cavity periphery. The center of the cavity receives the least cooling.
Increasing the heat removal capability of passive cooling systems will increase the current carrying capability of the rotor providing increased rating capability of the generator whole maintaining the advantage of low cost, simple and reliable construction.
U.S. Pat. No. 5,644,179, the disclosure of which is incorporated by reference describes a method for augmenting heat transfer by increasing the flow velocity of the large single flow circulation cell by introducing additional cooling flow directly into, and in the same direction as, the naturally occurring flow cell. This is shown in FIGS. 4 and 5. While this method increases the heat transfer in the cavity by augmenting the strength of the circulation cell, the center region of the rotor cavity was still left with low velocity and therefore low heat transfer. The same low heat transfer still persists in the corner regions.
The above-mentioned needs are addressed by the present invention, in which the heat removal capability of a passive cooling system is improved by driving more cooling gas into the cavities formed between the concentric end turns, thereby reducing the regions of stagnant or low momentum flow and increasing heat transfer. More specifically, the present invention provides scoop structures as coolant flow deflectors to enhance coolant flow into the cooling cavities thus increasing the flow heat transfer rate.
Accordingly, as an embodiment of the invention, a dynamoelectric machine rotor is provided, having axially extending coils and end turns extending axially beyond at least one end of the body portion of the rotor with one or more spaceblocks located between concentric end turns. In one embodiment of the invention, at least one and preferably at least the inner spaceblocks have a scoop defined at the radially inner end of the forward facing side thereof, to intercept and direct coolant fluid flow radially outwardly into the respective cooling cavity.
In another embodiment, the spaceblock profile is modified to defined generally continuously curved circumferentially facing surfaces to intercept and direct coolant fluid flow radially outwardly into the respective cooling cavity and to facilitate the circulation of the cooling flow through the respective adjacent cavities.

Spaceblock scoops for enhanced rotor cavity heat transfer


A method of operating an engine is provided. The engine may have a housing with one or more combustion chambers, including a first combustion chamber. The engine may also have a piston in fluid communication with the first combustion chamber. The method may include combusting fuel in the first combustion chamber, thereby producing combustion gas that expands and drives the piston during a first combustion-gas-expansion stroke of the piston. The method may also include compressing at least part of the combustion gas in the first combustion chamber during a compression stroke of the piston. Additionally, the method may include, between commencement of the first combustion-gas-expansion stroke and completion of the compression stroke, releasing part of the combustion gas from the first combustion chamber. The method may also include, subsequent to completion of the compression stroke, expanding at least part of the combustion gas against the piston during an additional combustion-gas-expansion stroke of the piston.

Many systems use engines to produce power for performing various tasks. Engines often produce power by executing a power cycle that includes introducing fuel and air into a combustion chamber and combusting the fuel with the air in the combustion chamber to produce high-pressure combustion gas that expands in the combustion chamber and drives a working member, such as a piston. In many cases, the power cycle that an engine executes includes releasing the combustion gas from the combustion chamber to accommodate introduction of new fuel and air into the combustion chamber during a subsequent power cycle. Often, the engine releases the combustion gas from the combustion chamber after it has expanded once. Unfortunately, releasing the combustion gas from the combustion chamber this quickly may have undesirable results. For example, releasing combustion gas from the combustion chamber after expanding the combustion gas only once may substantially reduce the temperature and pressure of the combustion gas before hydrocarbon particles in the combustion gas have significant time to regenerate.
U.S. Pat. No. 6,443,108 to Brehob et al. ("the '108 patent") shows an engine that executes a power cycle that includes retaining combustion gas in a combustion chamber after the combustion gas has expanded once. The power cycle disclosed by the '108 patent includes an intake stroke wherein an intake valve is open as a piston of the engine moves in a direction that increases the volume of the combustion chamber so that air fills the combustion chamber. Subsequently, the engine closes the intake valve and holds an exhaust valve closed so that the combustion chamber is closed while the piston compresses the air during a compression stroke. With the intake valve and exhaust valve still closed, the engine of the '108 patent then combusts fuel in the combustion chamber, producing combustion gas that drives the piston through a first expansion stroke.
The engine then holds the intake and exhaust valve closed while the piston compresses the combustion gas in the combustion chamber during a second compression stroke and the combustion gas expands and drives the working member through a second expansion stroke. The '108 patent also discloses that the engine may combust additional fuel in the combustion chamber during the second compression stroke and/or the second expansion stroke. After the second expansion stroke, the engine of the '108 patent opens the exhaust valve so that the piston drives the combustion gas out of the combustion chamber during an exhaust stroke.
Although the engine of the '108 patent executes a power cycle that includes retaining the combustion gas in the combustion chamber after it expands once, certain disadvantages persist. For example, retaining all of the combustion gas in the combustion chamber during the second compression stroke and the second expansion stroke may result in very high temperatures and pressures in the combustion chamber during these phases of operation. This may be especially so because the engine of the '108 patent combusts additional fuel in the combustion chamber during the second compression stroke and/or the second expansion stroke. Very high temperatures and pressures in the combustion chamber during the second compression stroke and the second expansion stroke may create a number of undesirable results, such as high production of NOx and high stress on the components of the engine.
The engine and methods of the present disclosure solve one or more of the problems set forth above.

Engine and method for operating an engine