A spirometer includes an expansible chamber of the piston type fitted with an indicia strip. The indicia comprise two columns of alternating light and dark bars. The columns are offset from one another by one-half the thickness of a bar and are respectively viewed by two photodetectors which generate signals which are shifted 90.degree. from one another as the columns pass through their respective fields of view. The signals are continuously sampled as digital words and consecutive words are compared to determine whether a counter should be incremented or decremented by one or two counts.

Spirometers are used to measure forced vital lung capacity usually of a human subject. A spirometer now in general use includes an expansible chamber having a movable piston fitted with a molded rolling rubber seal which comprises a movable boundary of the expansible chamber. The subject expires air through a tube connected to an opening into the chamber thereby causing the piston to move, expanding the chamber. A recording surface in the form of a removable card is attached to the piston and a pen is drawn across the face of the card at a constant velocity as the subject exhales into the expansible chamber. There is thus obtained on the card a plot of the volume of expiration flow as a function of time. The disadvantage of this type of spirometer is that its readout is purely in mechanical format and hence not readily adaptable to interfacing with computing devices which can perform certain pertinent lung function calculations, given the spirometer measurements.
It is important in using spirometers that any device used to measure the movement of the expansible chamber piston exert an absolute minimum influence thereon so as to prevent distortion of the measurement. For the same reason any means used to convert spirometer mechanical measurements to an electrical format should exert an absolute minimum influence on the quantitative measurements.
According to the present invention a spirometer has a fixed case, a portion of which forms the fixed boundaries of an expansible chamber, and a movable piston fitted with a molded rubber seal which forms the movable boundaries of the expansible chamber so that the piston and fixed case move relative to one another as a function of the quantity of air exhaled by the subject. The piston and case are coupled to one another by means such as a radiant energy transducer affixed to one and indicia on the other which pass through the field of view of the transducer as the piston moves relative to the case and to which the transducer responds to generate a first distinctive cyclically repeating series of digital numbers when movement is in a first direction and a second distinctive cyclically repeating series of digital numbers when movement is in the opposite direction. A logic circuit is provided which combines one of the numbers with the next generated number to form a new number which is analyzed in a look-up table to determine whether a counter should be incremented or decremented. The counter thereby contains a number which is a function of the quantity of air exhaled by the subject.
In the embodiment to be described the radiant energy transducer comprises a pair of reflective object or photo detectors affixed adjacent to one another to the case or to brackets affixed to the case and which view individual fields of view through which indicia in the form of alternate light and dark bars pass as the piston moves. The signal from either one of the reflective object detectors is a lower level sine wave which is conditioned and converted to a rectangular wave. The fields of view are off-set relative to the indicia so that the wave from one detector is out of phase with the wave from the other detector. There is thus instantaneously available from the detectors a two digit word, one digit from each detector, and a distinctive cyclically repeating sequence of four such words for continuous movement of the piston in one direction and the same four words in a cyclically repeating sequence of words for movement in the opposite direction except that the sequence is reversed. As will be explained, two such successively generated words unambiguously denotes that the piston has not moved or has moved less than the indicia pitch, or that the piston has moved one indicia pitch and the direction in which it moved. As explained above, two such successive words are combined to form a new word which is searched for in a look-up table to thereby control the aforementioned counter.
More specifically, the indicia comprise two columns of alternating light and dark bars. The longitudinal axes of the columns are arranged to be parallel to the line of piston movement so that each column passes under a respective reflective object sensor as the chamber expands or contracts. The bars of one column are slightly displaced with respect to the bars of the other column or alternately, a single column is used and the reflective object sensors are slightly displaced with respect to one another along the line of piston movement to allow the logic tests to monitor the direction of piston travel. The alternating light and dark bars of the columns passing under the reflective object sensors cause the outputs of these sensors to switch between the high logic state, (1), and their low logic state, (0). These transitions are counted in appropriate electronic circuits comprised of the aforementioned look-up table and counter to provide a measure of total piston displacement and hence a present volume or differential volume of the expansible chamber in the form of an electrical signal.
It is the main object of this invention to provide an accurate spirometer having an electrical output.
One advantage of the invention is that it can easily be retrofitted to existing spirometers.
Another advantage of the invention is that it allows a spirometer to generate an electrical output signal which can be directly coupled into computing circuits.
A further advantage of the invention is that it provides a means for use in a spirometer for generating an electrical spirometer output signal without mechanically loading the moving elements of the spirometer.

Optical digitizer for measuring spirometer output


Seepage of water and other impurities into hermetically sealed on plastic encapsulated modules leads to eventual device failure, as conductor material corrodes and opens, or electromigrates to establish conductive trails across a substrate, shorting the conductors. To forewarn of such failure, a sensing device defined as a separate chip is packaged in the same module with the circuit to be checked, with pinouts that can be tested with a circuit that is usually external. The sensor makes use of the moisture-induced migratory behavior that causes the problem, using a highly migratory metal or alloy to define paired electrodes spaced as closely as 2 micrometers apart. The metal of the electrodes undergoes rapid ionization and migration in the presence of trace amounts of moisture, dissolved ionic contaminants, and a small potential difference across the electrodes. Two volts applied to the sensor conductors by the sensor circuit will output a voltage if even a minute current is flowing between the electrodes permitting "go/no-go" decisions to be made regarding use of the module. The moisture which actuates the sensor, triggers the circuit long before the level of seepage and electromigratic represents present danger of circuit failure, and long before other types of sensors would indicate the existence of a problem.

The invention relates to the failure of encapsulated circuits such as multi-chip modules resulting from contamination-induced physical deterioration of the conductor metal taking place within the package, generally after the device has been produced contaminant-free, but after being stored in a humid environment for a period of time. The most prevalent cause of such failure is the entry of moisture with dissolved ionic contaminants into the package.
The penetration of moisture into hermetically sealed electronic packages or the permeation of moisture through plastic in non-hermetically sealed packages, especially in the presence of small amounts of ionic contaminants (low parts per million of chloride ion, for example), is known to cause device or circuit failure. See for example, J. J. Licari, Handbook of Polymer Coatings For Electronics, (Noyes, 1990). The failure mechanisms are generally moisture and ion-induced chemical corrosion of a layer of thin film metallization, of aluminum, nichrome, or copper for example. These impurities cause electrochemical phenomena such as metal migration that catastrophically bridge and short out closely spaced conductors. Or, in bi-metallic wire bonds, such as gold to aluminum, resistances may increase and electrical opens occur while leakage currents increase. See G. Harman, Wire Bond Reliability and Yield, (ISHM Monograph, 1989), and J. J. Licari and L. Enlow, Hybrid Microcircuit Technology Handbook, (Noyes Publications, Park Ridge N.J., 1988).
It would be desirable to incorporate a moisture and contamination sensor in every multichip module so that the penetration of water through hermetically sealed or plastic-encapsulated electronic modules can be rapidly detected. Such a detector could be used to make "go-no go" decisions for modules that have been stored a long time in various harsh environments before deploying them in flight hardware and other critical applications, and would also be useful in deciding if modules already in service need to be replaced.
No such sensors exist today, despite considerable research and experimentation. Some tests destroy the modules, and most are awkward and time consuming to implement. To date, considerable work has been done on moisture sensors that are based on changes in the dielectric properties of thin film porous capacitor materials. This approach has been proven unsatisfactory because each chip had to be calibrated separately, and would then drift out of calibration after assembly and screen testing.
Currently used sensor chips such as Sandia Laboratory's ATC series are based on triple track resistors of thin film aluminum. However, they are not sensitive enough to show rapid resistance changes within or between the conductor lines, even after thousands of hours of biased 85/85 humidity/temperature exposure. Because of this, HAST (Highly Accelerated Stress Test) is being employed. However, it has been difficult to correlate HAST results with long term 85.degree. C. /85% relative humidity test results. Cynthia Murphy et al of Microelectronics Computer Technology Corporation (MCC) reported at the 1994 Multichip Module Conference in Denver that the 141.degree. C. temperature used by MCC in their HAST test was much too high for getting meaningful results on epoxy encapsulated chips. Degradation of the epoxy molecular structure occurred under HAST conditions which introduced new failure mechanisms and obfuscated any correlation with real-life expectancy. Although the Sandia chips are still excellent test sensors they are best used to initially qualify a material system or to obtain reliability data.
Special test chips have been designed to study moisture and ionic penetration onto active semiconductor devices based on changes in electrical resistance taking place due to corrosion occurring in thin film aluminum conductors (triple track resistors), or changes in capacitance that occur in porous oxide capacitors. (J. N. Sweet et al., Proceedings of the 41st Electronic Components and Technology Conference, 1991).
Other approaches depend on capacitance changes occurring in a capacitor device or a porous dielectric due to the condensation of moisture. These techniques require cooling a hermetically sealed package until the dew point of the internal ambient fluid is reached and the moisture condenses. U.S. Pat. No 4,224,656 to Sosniak and 4588943 to Hirth speak to this. Again these approaches require careful calibration of each chip, which is expensive to start with, and exposure to elevated temperatures throws off the settings and re-calibration is required. Still other approaches measure leakage currents or conductance of an integrated circuit, which has moisture condensing between the conductor lines resulting in a measurable increase in conductance due to the presence of the electrolyte.
Whatever the mechanism, it is particularly important to have some kind of moisture reporting device for electronics modules such as aircraft, missile or computer components, that have been stored for extended periods of time in warm, humid environments. Beyond military and high-tech applications and anything involving electronics, a suitable moisture sensor/indicator could also be used in any moisture-sensitive applications such as packaged commercial or consumer optical instruments, foods or pharmaceuticals.
There is a need for such a simple chip-mounted moisture sensing device that can serve a "go/no go" function, incorporated in multichip circuits to determine if moisture has penetrated and has affected, or has a high likelihood of affecting, the reliability of the modules, and which may be broader in its application to be useful in many situations in which the presence of moisture is of concern.


This invention is a process for the chromatographic separation of a fluid mixture in which the mixture is contacted with an ion-exchange resin, eluted through the resin under conditions such that the rate of passage of one component of the mixture through the resin bed is retarded relative to the rate of passage of a second component of the mixture, and a first product stream rich in said first component and a second product stream rich in said second component are recovered. The invention involves the use of an ion-exchange resin made from a copolymer which is prepared in a multi-stage polymerization process. The use of this resin is found to provide fast separation kinetics and increases the overall speed and efficiency of the separation. This invention is particularly suited for fructose/glucose separations in the preparation of high fructose corn syrup.

This invention relates to chromatographic separations, particularly industrial scale chromatographic separations made using an ion-exchange resin as the separating medium.
Chromatographic separations of various substances can be accomplished using ion exchange resins as the stationary phase. Such processes use anion or cation exchange resins to separate mixtures of organic compounds, mixtures of organic compounds and salts, mixtures of acids and salts, and salt mixtures. Of particular commercial importance is the separation of fructose from glucose and oligosaccharides in the production of high fructose corn syrup (HFCS). In this process, mixtures of glucose and fructose are passed through one or more columns of a strong acid type ion exchange resin, most typically in the calcium form. The passage of the fructose through the column is retarded relative to that of the glucose, so there can be obtained separate product streams containing high proportions of fructose and glucose. The high fructose-containing stream is then used as a sweetener for many foodstuffs, such as soft drinks. This process is illustrated by Welstein and Sauer in "Separation of Glucose and Fructose: Effects of Resin Characteristics on Separation", in Ion Exchange Technology, Naden and Streat, eds. Society of Chemical Industry, London, pp. 466-471, incorporated herein by reference.
The ion-exchange resin used in such chromatographic separations is typically a plurality of crosslinked copolymer particles which contain anion or cation-exchange groups. Previous to this invention, this resin was a gel-type resin wherein the copolymer is prepared by a one-step suspension polymerization process using a low to moderate level of cross-linker and little or no inert diluent. As used hereinafter, the term "conventional one-step process" refers to a process like that described in U.S. Pat. No. 3,044,905, the teachings of which are incorporated herein by reference.
Although good chromatographic separations can be achieved with the above-described gel resins, improvements which result in a faster, more efficient and/or higher yield operation of the column are always desirable. Thus, it has been attempted to modify the ion-exchange resin to improve its kinetics. All other things being equal, faster exchange kinetics would provide several decided advantages. For example, at a given purity and yield, faster exchange kinetics would permit the column to be operated more rapidly (i.e., use higher feed rates). Alternatively, higher yields and/or product purities could be obtained at equivalent operating conditions if the resin had improved kinetics. Another advantage is that less desorbing solvent could be used, thereby reducing the expense of separating same from the product. Faster kinetics would also allow the use of larger resin particles, which permits a faster feed rate and/or higher feed concentration, thereby obtaining equal or better yield and purity without increasing pressure drop across the bed. A resin having faster kinetics would also permit the feed concentration to be increased in order to obtain a faster production rate.
Besides kinetics, another important parameter of a resin is its flow characteristics, i.e., the ease with which a liquid flows through a bed of the resin. It is desirable that the mobile phase move rapidly through the resin at low pressures. The equipment normally used in commercial chromatographic separation cannot withstand high pressures, so the flow rate cannot be greatly increased merely by increasing the pressure on the mobile phase.
It has been found that most modifications which improve the kinetics of conventional ion-exchange resins simultaneously diminish their flow characteristics. It is known that the kinetics of the resin can be improved by decreasing the particle size or increasing the water retention capacity. Unfortunately, both of these modifications diminish the flow characteristics of the resin so that, at a given pressure, a lower rate of sure, a lower rate of flow of the mobile phase is obtained. In practice, the benefit of the improved kinetics is at least offset by the undesirable worsening of the flow characteristics.
Accordingly, it would be desirable to provide a process for the chromatographic separation of a mixture of two or more materials, using an ion-exchange resin as the stationary phase, wherein a faster, more efficient or higher purity separation is achieved.

Chromatographic separation using ion-exchange resins


A memory management method, a memory control circuit unit and a memory storage device are provided. In an exemplary embodiment, the memory management method includes: receiving a first write command and first write data and obtaining a first number; programming the first write data and moving first storage data stored in a plurality of first physical programming units, where a total number of the first physical programming units conforms to the first number; receiving a second write command and second write data and obtaining a second number; programming the second write data and moving second storage data stored in a plurality of second physical programming units, where a total number of the second physical programming units conforms to the second number; and erasing at least one physical erasing unit. Accordingly, waste of system resource in the data merging procedure may be reduced.

Technical Field
The disclosure relates to a memory management mechanism, and more particularly, to a memory management method, a memory control circuit unit and a memory storage device.
Description of Related Art
The growth of digital cameras, mobile phones, and MP3 players has been rapid in recent years. Consequently, the consumers' demand for storage media has increased tremendously. A rewritable non-volatile memory is one of the most adaptable memories for portable electronic products such as laptop computer due to its data non-volatility, low power consumption, small volume, non-mechanical structure and high read/write speed. A solid state drive (SSD) is a memory storage device which utilizes a flash memory as its storage medium. For these reasons, the flash memory has become an import part of the electronic industries.
Generally, the memory storage device releases available physical erasing units by performing a garbage collection procedure so that new data may be stored. During the garbage collection procedure, the memory storage device determines how many units of data should be collected at background per each unit of data being written according to a predetermined garbage collection ratio value. However, the use of the predetermined garbage collection ratio value is unable to instantly increase or decrease the number of physical programming units to which valid data are to be retrieved in response to a storage state of the valid data (e.g., a data volume of the valid data) in the memory storage device, resulting in waste of system resource or pointless dropping of data access speed.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present disclosure. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present disclosure, or that any reference forms a part of the common general knowledge in the art.

Memory management method, memory control circuit unit and memory storage device


A method of monitoring and controlling an active environmental control system to impose energy efficient use of the system. The method includes the steps of monitoring a calling device for a change in calling data, time and date stamp the change in calling data, detecting a change in status of a plurality of physical sensors located within the system, wherein the state of each sensor represents a condition of the environment in which the system resides, time and date stamp the change in status of the plurality of physical sensors, measuring the temperature of a plurality of temperature locations within the system, time and date stamp the measured temperature of the temperature locations, storing for an extended period the calling data, the status change of the physical sensors and the measured temperature of the plurality of temperature locations, together with the respective time and date stamp, in a memory of the system, filtering the calling data, the physical sensors status change and the measured temperature for a system control trigger to identify system control trigger data, extracting a probability decision, to predict a direction of trend, by comparing recent system control trigger data with prior recorded system control trigger data, weighting the system control trigger data, based on the probability decision that the data is causing the output event trigger, in order to effect a desired change in output, and controlling the system based on the weighted system control trigger data.

The prior art includes heating/ventilation and air conditioning (HVAC) systems which typically include a furnace or boiler to heat air or water. The system includes a means of conveying the heat to other locations. The conveying means is typically ductwork for a furnace and piping for a boiler. The air conditioning half of the system typically includes a compressor, condenser, evaporator and a metering device. A thermostat is coupled to a controller for controller the above components of the system.

Energy efficient method of monitoring and controlling an HVAC system


A sheet discharge device includes: a conveying portion which conveys the sheet in a conveying direction with the sheet interposed between a first roller and a second roller; a first conveying guide; a second conveying guide; a rotating portion which is disposed on a shaft of the first roller and has an outer diameter larger than that of the first roller; and a guide portion which is provided in the first conveying guide and in which an interval between the guide portion and the opposite second conveying guide becomes narrower toward a downstream side in the conveying direction, the guide portion being located at a position corresponding to the rotating portion in a sheet width direction orthogonal to the conveying direction.

Field of the Invention
The present invention relates to a sheet discharge device which discharges a sheet, and an image forming apparatus having the sheet discharge device.
Description of the Related Art
A conventional sheet discharge device discharges a sheet such as a transferred sheet on which an image is formed from a main body of the image forming apparatus. The sheet discharge device includes a driving roller which receives a sheet on which an image is fixed by a fixing device to convey or discharge the sheet, and a driven roller which is driven and rotated by being pressed against the driving roller.
When discharging the sheet from the main body of the image forming apparatus onto a discharge tray, the sheet discharge device rounds or skews on the sheet discharge tray due to thermal deformation after fixing, which causes problems in terms of stacking properties. For this reason, the sheet is slightly curved in a width direction orthogonal to a conveying direction (discharge direction) by stiffening rollers to perform stiffening and ensure the stacking properties.
Specifically, as a conventional sheet discharge device, a configuration has been proposed in which a stiffening roller having a diameter larger than that of the driving roller is provided on the roller shaft of the driving roller, and the sheet is slightly curved in the width direction orthogonal to the conveying direction by the stiffening roller and is discharged in the state of being stiffened (Japanese Patent Laid-Open No. H2-305771).
However, in the conventional sheet discharge device, when a thick sheet is conveyed, an entry angle of the sheet to the stiffening rollers having a larger diameter than that of the driving roller becomes worse than the entry angle of the sheet to the driving roller, there is a problem which causes folding or jamming of edge of the sheet (end of the sheet).
Therefore, it is desirable to prevent folding or jamming of the edge of the sheet (end of the sheet) due to the leading end of the sheet abutting on the surface of the stiffening roller.

Sheet discharge device and image forming apparatus


A stuffed ribbon cartridge for a serial impact printer includes flexible leaders for guiding the ribbon from a stationary storage position to a movable print point. In order to place tension on the ribbon which is stored in the cartridge in a stuffed condition, a clip which pinches the ribbon so as to produce a drag force on the ribbon is located adjacent the print point and spaced from the cartridge by a substantial length of the flexible leader.

This invention relates to impact printers and, more particularly, to impact printers where a ribbon moves between a ribbon storage area and a print point to continuously supply fresh ribbon to a position between a character element and a print receiving medium.
Copending applications Ser. Nos. 833,257, filed Sept. 14, 1977 and abandoned in favor of copending application Ser. No. 98,773, filed Nov. 30, 1979, Ser. No. 833,270, filed Sept. 14, 1977, Ser. No. 833,269, filed Sept. 14, 1977, now abandoned and Ser. No. 873,714, filed Jan. 30, 1978, now abandoned disclose ribbon cartridges for impact printers which include flexible leaders or guides which guide the ribbon from the stationary storage area within the cartridge housing to a movable print point. By utilizing the flexible leaders so as to permit the storage area to remain stationary, it is possible to store much larger amounts of ribbon within the cartridge without affecting performance of the printer since the carriage for the printing mechanism need not move the stored ribbon, but merely that portion of the ribbon which is guided to the print point by the flexible leaders. Since a large amount of ribbon may be stored within the cartridge, the operator of the printer is not required to change the cartridge as often and thus avoids the risk of defacing the print receiving medium during replacement of the cartridge, e.g., smearing may be avoided. In addition, the use of a cartridge capable of substantial ribbon storage is more cost-efficient when one considers that the cartridge is, in effect, disposable. In other words, where the capacity for ribbon storage is quite large, the ratio of the cartridge mechanism cost to the ribbon is reduced and the overall cost of the cartridge per strike is decreased.
In the cartridges disclosed in the aforesaid application, the ribbon is stored on reels. The supply reel stores the ribbon prior to passage past the print point and the takeup reel stores the ribbon after passage from the print point. By driving the take-up reel, some control on the tension of the ribbon may be obtained. In this connection, it will be understood that the tension on the ribbon is important, particularly when flexible leaders are utilized, in order to assure that the ribbon remains taut at the print point while at the same time not creating excessive drag on the ribbon through the leaders.
In a stuffed ribbon cartridge, there may be no reels or at most one reel and control on the tension of the ribbon becomes more problematic. If a drag is placed on the supply of ribbon within the cartridge, that drag is magnified through the length of the leaders and can adversely affect the performance of the cartridge. In this regard, it will be understood that it is important that the ribbon move relatively freely through the long flexible leaders between the storage area and the print point for proper operation of the cartridge and the printer.

Ribbon tensioning for a cartridge with flexible guides


A four quadrant analog multiplier circuit including first to third squaring circuits 1 to 3 each of which is composed of first and second differential circuits each of which is formed of first and second metal-oxide semiconductor (MOS) transistors M.sub.1 and M.sub.2, M.sub.3 and M.sub.4, M.sub.5 and M.sub.6, M.sub.7 and M.sub.8, M.sub.9 and M.sub.10, and M.sub.11 and M.sub.12. A gate width-to-length ratio W.sub.2 /L.sub.2 of the second MOS transistor M.sub.2 is larger than a gate width-to-length ratio W.sub.1 /L.sub.1 of the first MOS transistor M.sub.1. A gate of the first MOS transistor M.sub.1, M.sub.5 and M.sub.9 of each first differential circuit is connected to a gate of the second MOS transistor M.sub.4, M.sub.8 and M.sub.12 of the corresponding second differential circuit. A gate of the second MOS transistor M.sub.2, M.sub.6 and M.sub.10 of each first differential circuit is connected to a gate of the first MOS transistor M.sub.3, M.sub.7 and M.sub.11 of the corresponding second differential circuit. The gates of the MOS transistors M.sub.1 and M.sub.9 are connected in common to receive a first input signal V.sub.1, and the gates of the MOS transistors M.sub.5 and M.sub.11 are connected in common to receive a second input signal V.sub.1. Drains of the MOS transistors M.sub.1, M.sub.3, M.sub.5, M.sub.7, M.sub.10, and M.sub.12 are connected in common to a first output current terminal, and drains of the MOS transistors M.sub.2, M.sub.4, M.sub.6, M.sub.8, M.sub.9, and M.sub.11 are connected in common to a second output current terminal. A differential current between the first and second output current terminals is indicative of a product of the input signals V.sub.1 and V.sub.2.

1. Field of the Invention
The present invention relates to an analog multiplier circuit, and more specifically to a high precision four quadrant analog multiplier circuit of a so-called floating input type, which can be effectively used particularly for modulation and demodulation of an analog signal.
2. Description of Related Art
Known conventional analog multiplier circuits include a Gilbert multiplier circuit composed of only bipolar transistors, a MOS multiplier circuit formed by substituting MOS transistors for the bipolar transistors of the Gilbert multiplier circuit, and a CMOS multiplier circuit formed by constituting the Gilbert multiplier circuit by CMOS transistor circuits.
In the Gilbert multiplier circuit, when the magnitude of each of two input signal voltages V.sub.1 and V.sub.2 is extremely smaller than 2 V.sub.T (where V.sub.T =kT/q, K: Boltzmann's constant, T: absolute temperature, q: electric charge of unit electron), an output current is substantially in proportion to V.sub.1 .multidot.V.sub.2. Namely, when each of the input signals is a small signal, the Gilbert circuit functions as the multiplier. In addition, each of the input signals must be applied in the formed of a differential signal
Similarly, the MOS multiplier circuit functions as a multiplier when a pair of input signals are small. In addition, this MOS multiplier circuit is disadvantageous in that a linear operation range for one of the input signals is smaller than that for the other input signal. Furthermore, the CMOS multiplier circuit also has only a narrow input signal range which can ensure a good linear operation. In each of the MOS multiplier circuit and the CMOS multiplier circuit, furthermore, each of the input signals must also be applied in the form of a differential signal.
As mentioned above, the conventional multiplier circuits have been disadvantageous in that the dynamic range is narrow and each input signals must also be applied in the formed of a differential signal.

Four quadrant analog multiplier circuit of floating input type


An artificial water plant system for trapping bottom sediments in water to protect sand beach against erosion in which the water plant comprises a rod-shaped or tubular molding product having a circular or non-circular cross sectional shape and comprising a thermoplastic elastomer alone having a flexural modulus of 500 to 5,000 kg/cm.sup.2 or a composite body comprising a sheath portion constituted with the thermoplastic elastomer and a core portion constituted with synthetic fiber bundles.

1. Field of the Invention
The present invention concerns an artificial water plant system installed on nearshore sea bottom and/or lake bottom, which has an objective of preventing seashores and/or lakeshores from being eroded by wave action by means of a control mechanism of sediment transport which consists of onshore bottom currents induced by wave-water plant interaction and wave energy dissipation by this system.
2. Description of the Prior Art
Rigid structures mainly made of concrete or stone materials such as coastal rivetments, groins, wave absorbing works and detached breakwaters have been constructed or installed so that large offshore waves do not directly reach a seashore. Such rigid structures however, involve an environmental problem of damaging existing ecosystems and worsen the landscape of a seashore. Another problem is that the sea bottom around these rigid structures is scoured by waves breaking and strong bottom currents induced by wave-structure interaction. Subsequently, these structures are subjected to subsidence and collapse.
Submerged breakwaters or artificial reefs have been developed and constructed for landscape conservation and water quality conservation due to a good exchange of sea water. They also, however, involve some problems likely to cause scouring due to waves breaking and strong bottom currents induced by wave-structure interaction and also present navigation hazards for ships.
On the contrary, flexible structures are also provided, such as fibrous or strand-like polymeric materials entangled with each other, nets or swingable rubber sheets. Such flexible structures are preferred in view of their water quality conservation properties since they swing by waves and have sufficient openings for sea water to pass through. In addition they have the advantage of not deteriorating the landscape since the structures are disposed on the sea bottom and do not appear above the water surface.
Since drag forces exerted on those flexible structures increase due to deposition of marine organisms on these structures, they tend to easily fall down due to the weight of deposits such as shells. Also, a screw propeller of a ship may easily catch these structures when the ship goes in the area of the structures, which results in both the ship and the structures being liable to suffer damage. Thus, they involve a drawback of resulting in problems in view of the long-lasting property of the aimed effect and durability. Thus, no effective means for practical use have yet been provided until the present invention.

Artificial water plant system for controlling sediment transport on a water bed


A method and apparatus for conversion between data representation formats and data including sound and text information are disclosed. Data representation formats include a string of characters in the text format, a digital representation of an acoustic wave form in the sound format, a reference to a data structure containing information about a word in the word format, a tree-like representation of the grammatical structure of the phrase in the phrase format and references to functions, objects and attributes in an underlying data model in the logic format. Software for a computer or a combination of hardware and software may be used as well as word and sound processors.

The present invention pertains to a method and an arrangement for conversion between data representation formats, said data comprising sound or text information. The invention specifically provides for a method and arrangement means for word and sound processing.
Natural language understanding has been the topic of research since the first days of Artificial Intelligence. The present invention is primarily intended for understanding spontaneous utterances, in written or spoken form, within a limited domain.
One current approach to this problem is to model a dialog flow for each operation that can be performed in a specific system, dividing each dialog into modes. For each mode, valid inputs and their consequences are listed. For example, the Philips SpeechMania(copyright) 99 product has been demonstrated with a pizza ordering application, where a user goes through dialog modes involving for instance selecting pizza toppings. A disadvantage of this type of technology is that the system will only understand the utterances expected in a given mode. If a user changes his drink order while he is expected to select pizza toppings, the system may fail to understand this. The degree to which the system xe2x80x98understandsxe2x80x99 the utterances in this kind of iteration is limited; each mode and the utterances valid therein must be anticipated by the developers, and directly related to the action the system takes as a response to user input.
Other speech recognition systems, such as those using the Java(trademark) Speech Grammar Format (JSGF), provide tags attached to an (often handwritten) grammar. The tags normally have some semantic meaning, regardless of how that semantic meaning was expressed. Words or phrases without semantic interest to the application (politeness phrases, articles, etc.) are ignored. Such an application then has a very simple parsing of the tags in order to act on the speech input. This requires manual adaptation of the application and grammar so that they work together, and cannot be said to xe2x80x98understandxe2x80x99 the spoken utterances.
More advanced approaches to natural language understanding make use of formalisms developed within the field of linguistics and computational linguistics. One currently popular formalism is Head-Driven Phrase Structure Grammars, which associates groups of lexical features with words, resulting in a grammar structure which can be used for parsing general natural language. Many of these linguistic formalisms could be used to perform some of the steps described in the present invention, but require much more work to be integrated into a complete language understanding interface to an application, and also substantial adaptation to new domains.
Some speech recognition systems use word spotting. This entails listening for certain key words and ignoring the rest of the spoken utterance. This may simplify the parsing component of a system, but does not allow the system to understand the details of the user""s utterance.
No commercial applications use the same grammar for both natural language generation and natural language understanding. Most current applications either understand a very simple subset of natural language, or require substantial manpower to adapt the natural language understanding system to a given application.
The present invention sets forth a method and an arrangement for word and sound processing. It solves the problem of simple natural language understanding, allowing users to interact with (for instance by giving commands and asking questions) machines using natural language, for instance in spoken or written form. Additionally, the method provides language independence by transforming linguistic utterances by the user to a semantic form which is independent of the original language used. This form may later be converted into another human language, thereby resulting in a simplistic translation. Furthermore, the present invention can automate the process of adapting domain specific natural language understanding to an application of the same.
The present invention does not attempt to solve the highly complex problem of general natural language understanding, but rather the understanding of a limited subset of natural languagexe2x80x94utterances which can be straight forwardly mapped to the domain of one or several data models or computer applications.
To achieve these aims and objectives, the present invention provides a method for conversion between data representation formats, where the data includes sound or text information. The data representation formats are text, sound, words, phrases, and logic. Those are combined as conversions between text or sound to words or vice versa, words to phrases or vice versa, and phrases to logic or vice versa. The formats include a string of characters in the text format, a digital representation of an acoustic wave form in the sound format, a reference to a data structure containing information about a word in the word format, a tree-like representation of grammatical structure of a phrase in the phrase format, where the leaf nodes of the tree-like representation are referenced to meanings of constituent words and conjunction information, and references to function, objects and attributes in an underlying data model in the logic format. The method includes the steps of converting text to words by using characters with separate words, converting words to text by concatenating the spelling of the constituent words, converting sounds to words by providing a continuous speech recognition system, converting words to sounds by providing a speech synthesis system, converting words to phrases by parsing, converting phrases to words by transversing the tree-like representation preferably from left to right and converting each leaf node to a word, converting phrases to logic by resolving or binding verb phrases to functions and noun phrases to objects in the underlying data model and converting logic to phrases by using knowledge of the grammar of the language used to create a phrase expressing the same semantics as in the original logic format.
The method further comprises:
converting text to words by using characters which separate words;
converting words to text by concatenating the spelling of the constituent words;
converting sound to words by providing a continuous speech recognition system;
converting words to sound by providing a speech synthesis system;
converting words to phrases by parsing
converting phrases to words by traversing said tree-like representation preferably from left to right and convert each leaf node to a word;
converting phrases to logic by resolving or binding verb phrases to functions and noun phrases to objects in said underlying data model;
converting logic to phrases by using knowledge of the grammar of the used language to create a phrase expressing the same semantics as the original logic form; and thus providing a computer word processing and sound processing means.
The invention here also includes the apparatus for accomplishing the conversion. There are means for converting text to words, words to text, sounds to words, words to sounds, words to phrases, phrases to words, phrases to logic and logic to phrases, typically in form of software or a combination of hardware and software.
The arrangement further comprises:
converting means from text to words, which uses characters which separate words;
converting means from words to text, which concatenates the spelling of the constituent words;
converting means for sounds to words, providing a continuous speech recognition system;
converting means for words to sound, providing a speech synthesis system;
converting means for words to phrases, which uses parsing;
converting means for phrases to words, which traverses said tree-like representation preferably from left to right and converts each leaf node to a word;
converting means for phrases to logic, which resolves or binds verb phrases to functions and noun phrases to objects in said underlying data model; and
converting means for logic to phrases, which uses knowledge of the grammar of the used language to create a phrase expressing the same semantics as the original logic form.
Further embodiments of the present invention are set out through the attached dependent claims. Also, said arrangement is able to provide the embodiments relating to said method.

Conversion between data representation formats


An electro-dynamic acoustic transducer has a pleated diaphragm in which an accordion-like alternating movement of the adjacent pleats is perpendicular to the radiation (acoustic) axis of the transducer. Front and rear pole plates cooperate to provide a magnetic field across the active area of the diaphragm. Each pole plate may be a "magnetic throat" constructed from a unitary casting of a ferrous magnetic material (such as an iron silicon alloy) having a number of apertures. In an exemplary embodiment, the open area at the rear of the pole plate may be approximately 1/3 the active area of the diaphragm, thereby providing a compression ratio of 3:1. The apertures are substantially uniformly distributed over the effective area of the diaphragm, to provide uniform acoustical coupling and prevent the occurrence of acoustical resonances and standing waves along the diaphragm's length. Each aperture in the front plate opens up such that the corresponding area at the inlet of the loading horn is substantially open, thereby providing a smooth transition through the magnetic pole plate to the external horn, with the apertures preferably designed with an exponential flare. These apertures may be tapered as part of the magnetic pole plate or the tapered portions may be formed separately from magnetic or non-magnetic materials, such as plastic or aluminum, and joined to a pole plate having corresponding apertures. In a preferred embodiment, each aperture is in the form of a horizontal slit extending across the active width of the diaphragm, and the apertures are arranged in a vertical array to cover this entire active area. Each slit increases in width as it tapers towards the front pole plate, providing the smoothest possible acoustical transition to the external horn.

U.S. Pat. No. 3,832,499 (Oscar Heil) discloses an electro-acoustic transducer in which a conductor is arranged in a meander pattern on at least one side of a flexible diaphragm. The flexible diaphragm is pleated or corrugated such that when the diaphragm is placed in a magnetic field oriented in a front to rear axis, with electrical current flowing perpendicular to the magnetic field in one direction in a given fold and in an opposite direction in an adjacent fold, the adjacent folds are alternately displaced to the right and to the left along a third axis perpendicular to both the front to rear axis and to the direction of the electrical current. The air spaces between adjacent folds facing one side of the diaphragm are expanded while the air spaces on the other side are contracted, thereby causing acoustic radiation to be propagated along the front to rear axis.
A two-part article in Speaker Builder (March and April 1982) by Kenneth Rauen discloses alternate designs for the diaphragm of a horn loaded "Heil Air Motion Transformer" ("AMT"), based in part on techniques previously published by Neil Davis (Audio Amateur, February 1977)
Another design for a horn loaded AMT is disclosed in U.S. Pat. No. 5,325,439 (Smiley) and was incorporated in a coaxial speaker marketed by Cerwin Vega (applicant's assignee) as model CATA-15.
However, none of the known prior art designs for a pleated diaphragm transducer provide for both substantially uniform acoustical coupling of the entire effective area of the diaphragm and substantially uniform magnetic flux through that same effective area. Furthermore, no previously known prior art design provides sufficient acoustical loading to match the mechanical impedance of the diaphragm and therefore such prior art designs are unable to maximize the efficiency of the transducer. Accordingly, the known prior art pleated diaphragm transducers are not readily adaptable for high power and high sound pressure level applications such as sound systems for concerts and motion picture theaters.

Horn loaded pleated ribbon high frequency acoustic transducer with substantially uniform coupling


A moving object identification method (10) for identifying and tracing an object (20) within a video image (14) such that the object (20) can act as a hot spot (30) as for an interactive computer/user interface (70). A plurality of tags (28) define the edges (26) of the object (20) and a plurality of hot spot borders (32) define the hot spot (30) such that the hot spot (30) and the object (20) generally coincide. A physical tag (28b) is optionally used to position the tags (28). Sensitivity to disappearance of the edges (26) is adjustable according to the relative size of a subtag (68) to the corresponding tag (28).

Manipulation of digitized video images, both still pictures and moving video presentations, is an important aspect of the present trend toward the introduction of "multimedia" into many aspects of our lives, as well as in modern aspects of more traditional endeavors such as, for example, the creation of motion pictures. A copending U.S. patent application Ser. No. 08/146,964, having an inventor in common with this present invention, teaches a method for converting a conventional "moving picture" video into a computer/user interface means. In accomplishing the method of that previous invention, it is necessary to identify, within the video presentation, particular objects of concern. As discussed in the above referenced disclosure, such identification can be quite laborious, and it was anticipated that methods for transferring some of that labor from the human operator to the computer might be developed in the future.
It was disclosed that the designation of "hot spots", consisting of objects within a moving video, were, ". . . accomplished by viewing each key frame and, at least until a more automated system is developed therefor, manually designating which, if any, objects or items of interest in the key frame are to be designated as the hot spots." (Reference numbers relating to the prior designation have been deleted in this quotation.) This present application is directed to a method and means for automating the identification of such objects and maintaining such identification through time. Although the present inventive method is intended to be used in conjunction with the production of interactive computer interface systems, it is not restricted to such applications.
An object in animated, or other specially prepared moving video images, can be rather easily identified, since such object can be created according to a specific easily distinguishable criterion (such as color, or the like) or, indeed, the pixel location of the object can be made a part of the data which describes the object within the computer even as the object is created. However, objects within a live action video, which video has not been specially produced nor specially prepared, cannot be so easily segregated.
Prior art methods for identifying objects in a video image, such that the object is defined according to computer understandable criteria, have included identifying edges, colors or color patterns and/or brightness levels which define the object. Such methods have been relatively effective for the identification and/or manipulation of still video images. For example, an object can be distinguished by known methods for automatically defining the outer edges thereof, and the object can then be operated upon. As examples of such operations, the object can be moved within the image, removed from the image, or changed in color, luminosity, or the like. More in the context of the present invention, the object could even then, once the image is defined in terms of a bit map, be used in the manner of an icon or a "hot spot", such that clicking on the area of the image within the object could cause the computer to initiate a response or further interaction with the end user. It should be remembered, however, that this sort of procedure does not transfer well into the realm of moving video images. Firstly, keeping track of the location of objects within a moving video image by storing a bit map of all such objects for all frames of the moving image would require a morass of data which would tax a computer's data storage capacity and slow down the operation of the computer. Secondly, although the amount of user interaction and labor required to perform the above described operations is well tolerable when working with a single still video image, an attempt to repeat such an operation thirty or so times for each second of a moving video would quickly reveal that this method is outside the realm of practicality.
One accepted method for separating objects within a moving video image has been based upon the color of portions of the image. One skilled in the art will be familiar with the "blue screen " method wherein portions of an image which are of a specific color (often, but not necessarily, blue) can be selectively removed from an image. This technique was used in television prior to the advent of digital image manipulation, and has been found to work well also when applied to the field of digital image manipulation. While this method works well for its intended purpose, it will generally only successfully distinguish, for example, a background from the foreground object(s). Furthermore, it requires a special setting in that the object(s) of concern must be originally "shot" (meaning photographed, video taped, or the like) against the special background color. Most importantly, although the background is distinguished from the foreground objects such that a computer can calculate the location of the objects in order to perform operations thereon (such as overlaying the objects upon a different background), different objects are usually not sufficiently identifiable in terms usable by the computer such that the objects can serve as means for computer/user interaction. Moreover, even in those special situations in which a video scene can be shot in front of a blue background or the like, and even in those unusual instances wherein there may be only a single object in the foreground such that there will be no confusion between objects, such prior art solutions do not address the problem of extensive data storage requirements and drain on computation resources, as discussed above.
Methods for identification of edges or complex color patterns within a video image are more effective for segregating specific "real world" portions of a video image, as compared to the more artificially induced background "blue screen" methods. However, such edge or color identification methods generally require relatively sophisticated computer analysis, and so are not suitable for real time image tracking, at least unless a great deal of expensive computing power is dedicated to such tracking. Even where a practically unlimited quantity of computer resources are available to the task, attempting to track moving objects within a video image according to such complex criteria has proven to be undesirably complicated. Where more than one object is to be tracked within the video, or where the objects are rapidly moving and/or changing relative shape within the video, the problems associated with such methods are exacerbated.
It has been brought to the inventor's attention that several prominent manufacturers of computer products have a need for a better means and/or method for identifying moving objects within video images such that the objects may be followed by a computer, in order to implement their own products. However, in spite of the fact that some of these companies have extensive research budgets and large and experienced research staffs, they have turned to the present inventor seeking a solution to this known problem.
To the inventor's knowledge, no workable method has existed in the prior art for quickly and easily identifying, for computer tracking and manipulation, objects within moving video images which is inexpensive and easy to implement and reliable. All prior art methods have either been extremely labor intensive and/or have required an inordinate amount of computing power to implement (or, even worse, have required an inordinate amount of computing power for an end user to utilize the product of such methods) and/or have not reliably identified objects such that a computer can track the objects within a video presentation without "losing" the objects or confusing them with the backgrounds or other objects in the video.

Object identification in a moving video image


A process is described for the production of anhydrosugars such as levoglucosan (1,6-anhydro-.beta.-D-glucopyranose), from liquids obtained by the fast thermal pyrolysis of pretreated lignocellulosics or celluloses. In this process, the pyrolytic liquids containing the anhydrosugars are produced with a substantially reduced amount of lignin-derived components by using as feedstock materials which have been previously delignified and then pretreated, or by preferential oxidation of the lignin fraction of a pretreated biomass during pyrolysis. The preparation from pretreated biomass of pyrolytic liquors from which the lignin derived chemical products of fast pyrolysis are absent or in low concentrations permits simpler and more economical recovery of crystalline levoglucosan and other anhydrosugars, or a more economical preparation of readily fermentable aqueous sugar solutions therefrom. A new procedure for the recovery of crystalline levoglucosan from such solutions is described.

This invention relates to an improved process for the production of sugars and anhydrosugars from biomass materials such as wood or other lignocellulosics, or from biomass derived materials as newsprint or other paper goods, wood pulps, waste fibre etc.
Scott & Pisorz U.S. Pat. No. 4,880,473 discloses a process for preparation of solutions of fermentable sugars using a fast pyrolysis of pretreated biomass. In that invention, the pretreatment was a dilute acid prehydrolysis which removed the majority of the hemicellulose fraction as well as the alkali and alkaline earth cations associated with the biomass. As a result, as much as 80% of the lignin appeared in the pyrolysis liquid as pyrolytic lignin, i.e. the volatile decomposition products primarily derived from the lignin fraction of biomass. A portion of these lignin-derived compounds can be separated by water extraction from the more soluble sugars and anhydrosugars derived from the cellulose fraction, and which are recovered in the aqueous phase.
It is well known that the alkaline cations associated with the biomass act to promote certain thermal decomposition reactions, in particular those reactions which lead to char or gas production. These cations are known to be able to be removed by treatment with very dilute acid at normal temperatures, such that the lignin, hemicellulose and cellulose fractions of the biomass are substantially unaffected. The resulting deionized biomass differs from that given a prehydrolysis pretreatment in that the hemicellulose content is retained in the solid pretreated lignocellulose.
The behaviour of deionized wood has been shown in laboratory batch pyrolysis reactions carried out at very small scale under vacuum with slow heating to be different from that of normal wood. The removal of the cations enhanced the yield of anhydrosugars derived from cellulose, and particularly increased the yield of anhydroglucose, (levoglucosan). Typically, deionization was carried out by batch-wise contacting of the wood with very dilute acid, for example 0.1% sulfuric or hydrochloric acid, and then washing it thoroughly with distilled or deionized water to remove the reagent. The deionized wood was then pyrolyzed under vacuum in microscale laboratory batch reactors in the absence of air or oxygen. Much poorer yields of levoglucosan were obtained from these batch reactions when carried out at atmospheric pressure. Sugars or anhydrosugars derived from the pyrolysis of the hemicellulose fraction have apparently not previously been reported as products obtained from fast pyrolysis of deionized lignocellulosics. This suggests that at the laboratory conditions used in earlier work of others, thermal fragmentation of the hemicelluloses predominated over depolymerization reactions.
Other methods of converting cellulose to fermentable sugars, mainly glucose, are carried out in the liquid phase and require digestion in acid. If this digestion is done using a strong acid, many undesirable and toxic side products are formed. If weak acid is used, poorer glucose yields and more dilute solutions are obtained. In this context, it is also known to use a weak acid treatment to prehydrolyze cellulosic raw material followed by enzymatic hydrolysis. This procedure can yield an improved product at higher concentrations compared to weak acid hydrolysis above. However this process is relatively complex and expensive. Other liquid phase methods such as those known as steamexplosion, may also be cited, for example in Hinger, U.S. Pat. 4,468,256 where glucose is produced from vegetable raw material by impregnating the raw material with dilute acid and subsequent heating to a temperature of above 250.degree. C. by means of high pressure steam. This heating step takes place in a short time accompanied by a sudden pressure rise. In these liquid phase acid digestion methods the principal product from the cellulose is glucose, and anhydrosugars such as levoglucosan are largely absent.
A pyrolysis process for the production of levoglucosan from wood has been described in Esterer U.S. Pat. No. 3,309,356 and in Peniston U.S. Pat. No. 3,374,222. These processes did not use any pretreatment of the wood but stated that it was unnecessary. Also, the pyrolysis process used gave a two-phase liquid. Further, the relatively long residence time of the condensable volatiles in the reactor, approximately 15 seconds, would reduce significantly the possible yields obtainable. In the above Esterer patent it was necessary to remove the lignin-derived material soluble in the aqueous phase by a solvent extraction procedure. In the Peniston patent, these materials as well as carbohydrate derived acids were removed by conversion to insoluble metal salts.
The oxidation of biomass materials in air or oxygen has been very extensively studied in combustion and gasification processes. In particular, the effect of added cations or of the indigenous cations of the wood on the combustion behaviour has been widely reported in connection with fire studies. The indigenous alkaline cations such as K, Ca, Na, Mg or additions of these cations are well known to be effective gasification catalysts in air or oxygen blown systems. Fast pyrolysis with added air to produce liquids and char from biomass has been reported as part of the LEBEN program in Italy, carried out under the sponsorship of the European Economic Community. In general, use of air or oxygen in the fast pyrolysis of biomass results in reduced liquid yields (20-40% vs. 50-80% for non-oxidative pyrolysis) and in degradation of the product in terms of yields of specific desirable chemicals.
There is a need for a more economic process for the deionization of wood or other biomass or biomass-derived materials for the purpose of carrying out a fast pyrolysis process for the conversion by thermal means of cellulose or hemicellulose to sugars and anhydrosugars, and which would allow these processes to become competitive with other processes for the conversion of cellulose or hemicellulose to anhydrosugars or fermentable sugars. Improvements in the fast pyrolysis process would also be valuable in reducing the cost of this method of conversion of hemicellulose or cellulose to sugars or anhydrosugars.

Process for the production of anhydrosugars from lignin and cellulose containing biomass by pyrolysis


An engine compression brake device is disclosed. The brake device has at least one camshaft which has at least one cam group with at least one firing cam and at least one brake cam, and has at least one cam follower which is functionally assigned to the firing cam and which is provided for actuating at least one gas exchange valve in a firing mode, and has a cam follower which is functionally assigned to the brake cam and which is provided for actuating at least one gas exchange valve in a braking mode. The brake device further has a switchover device which is provided for the switchover between the firing mode and the braking mode, where the switchover device is provided for converting a torque of the camshaft into a force for the switchover between the firing mode and the braking mode.

The invention relates to an engine compression brake device for an internal combustion engine of a motor vehicle, particularly a commercial vehicle.
An engine compression brake device is known from EP 2191106 B1, having a camshaft with at least one cam group, the same having at least one firing cam and at least one brake cam, having at least one cam follower which is functionally assigned to the firing cam and which is included for the purpose of actuating at least one gas exchange valve in firing mode, and having a cam follower which is functionally assigned to the brake cam and which is included for the purpose of actuating the at least one gas exchange valve in the braking mode, and having a switchover device which is included for the purpose of switching between the firing mode and the braking mode.
The invention particularly addresses the problem of reducing costs for an engine compression brake device and/or reducing the consumption of an internal combustion engine having such an engine compression brake device.
The invention proceeds from an engine compression brake device, having at least one camshaft with at least one cam group, the same having at least one firing cam and at least one brake cam, having at least one cam follower which is functionally assigned to the firing cam and which is included for the purpose of actuating at least one gas exchange valve in firing mode, and having a cam follower which is functionally assigned to the brake cam and which is included for the purpose of actuating the at least one gas exchange valve in braking mode, and having a switchover device which is included for the purpose of switching between the firing mode and the braking mode.
It is suggested that the switchover device is included to convert a camshaft torque into a force for switching between the firing mode and the braking mode. As a result, it is possible to utilize the torque and/or the rotational movement of the camshaft, such that there is no need for an actuator mechanism which supplies the force for the switchover, by way of example in the form of hydraulic pressure. Because the torque and/or the rotational movement of the camshaft is used for the switchover, there is no need for additional actuators which fundamentally generate an additional drag torque, such that it is possible to increase the efficiency of an internal combustion engine having such an engine compression brake device. In particular, the consumption of an internal combustion engine can be reduced as a result. However, particularly since there is no need for a corresponding actuator mechanism which directly provides force for the switchover, it is possible to reduce the number and/or complexity of actuators, thereby achieving a particularly inexpensive design. The term "cam group" is used to mean a group of cams which includes all the cams of the camshaft for a working cylinder of the internal combustion engine. The term "firing mode" is used to particularly mean a control of the gas exchange valves for combustion operation. The term "braking mode" is used to particularly mean a control of the gas exchange valves for braking operation, wherein a compression work within the working cylinder is used for the braking operation. The firing mode and the braking mode particularly differ in the activation times for the gas exchange valves. The term "switchover device" in this context is particularly used to mean a mechanism which is provided for switching between the firing mode and the braking mode. The term "provided" is particularly used to mean specially designed and/or equipped.
It is further suggested that the switchover device has at least one slotted element connected to the camshaft in a torque-proof manner which allows an axial sliding movement, the slotted element having at least one guide slot which is provided for converting a rotational movement of the camshaft into a linear switching movement of the slotted element. As a result, the rotational movement and therefore the torque of the camshaft can be easily used to switch the slotted element between two switch positions. The mechanical switching of the slotted element can then be converted into a switchover between the firing mode and the braking mode, such that it is possible to implement the switchover device with only mechanical components. An actuator required to initiate the switchover can be designed in the form of a simple electric or electromagnetic actuator.
The engine compression brake device preferably includes an actuator which is fixed in relation to the slotted element and which has at least one switch pin, which is provided to engage in the at least one guide slot and convert the rotational movement of the camshaft into the linear switching movement of the slotted element. This allows the actuator to have a simple, cost-effective design. In particular, the actuator need only be provided for the purpose of bringing the switch pin into engagement with the switching gate. The shifting force required in this case is much lower than a supporting force which is necessary when the actuator switches directly between the firing mode and the braking mode—for example, by acting directly on the cam follower. The actuator only needs to be supplied with current for the switchover between the firing mode and the braking mode. It is possible to dispense with an actuator which must be continuously active during the braking mode and/or the firing mode to maintain the switched state of the firing mode or the braking mode.
In addition, it is suggested that the switchover device has a rocker arm bearing which has a first terminal position functionally assigned to the firing mode, and a second terminal position functionally assigned to the braking mode. This allows a particularly simple mechanical design for the switchover device. Because of such a configuration, it is possible for the terminal position of the rocker arm bearing to determine whether the firing mode or the braking mode is selected, such that only the rocker arm bearing needs to be switched from one terminal position to the other terminal position to accomplish the switchover. This makes it possible to realize the switchover simply using mechanical means, without the switchover requiring an additional actuator, such that a simple and robust switchover device is required. The term "rocker arm bearing" is used to particularly mean a bearing for rocker arms used for actuating the gas exchange valves, which is designed to receive and redirect actuation forces acting on the rocker arm when the gas exchange valves are actuated.
In one particularly advantageous embodiment, the engine compression brake device has at least two rocker arms, each of which comprises one of the cam followers, which are able to pivot about a rocker arm axis determined by the rocker arm bearing for the purpose of actuating the gas exchange valve. By connecting the rocker arm to the rocker arm bearing which can be switched between the first terminal position and the second terminal position, the one rocker arm or the other rocker arm, depending on the terminal position, can have a functional connection to the camshaft, such that it is possible to easily switch between the firing mode and the braking mode.
The rocker arm bearing is preferably designed to be switched by means of the torque of the camshaft between the two terminal positions. As a result, it is possible to utilize the torque of the camshaft, thereby achieving high efficiency. Preferably, the actuating forces acting on the rocker arms when the gas exchange valves are actuated are redirected to the rocker arm bearing in such a manner that a torque is applied which can be utilized for the switching from the one terminal position to the other terminal position.
The switchover device advantageously has at least one spring-loaded detent element which is designed to fix the rocker arm bearing in the two terminal positions. This makes it possible to support the actuating forces applied to the rocker arm bearing in the firing mode and the braking mode without the need for an actuator to be continuously active. This achieves particularly high efficiency.
It is also suggested that the switchover device has at least one detent contour element mounted to allow movement, wherein the at least one detent element of the rocker arm bearing is supported against the same. Because the detent contour element is mounted to allow movement, the terminal position lock of the rocker arm bearing can be easily released. At the same time, forces which are necessary for releasing the detent element can be significantly less than forces which can be supported by the detent element for fixing the rocker arm bearing. As a result, the rocker arm bearing can be secured via the detent element against strong actuating forces, while at the same time the secured position of the rocker arm bearing can be easily released.
It is further advantageous if the detent contour element has at least two locking positions, and the slotted element is provided to pivot the at least one detent contour element from the locking positions into at least one intermediate position between the locking positions. As a result, the torque and the rotational movement of the camshaft can be utilized to release the secured position of the rocker arm bearing, whereby the complete switchover between the firing mode and the braking mode is achieved by the torque and the rotational movement of the camshaft, and the actuator of the engine compression brake device is only provided for initiating the switchover.
In addition, it is suggested that the slotted element has two switch positions, and has an actuating pin which is designed to switch the at least one detent contour element from the first locking position into the intermediate position when in the first switch position, and from the second locking position into the intermediate position when in the second switch position. In this way, the slotted element can be mechanically coupled to the detent contour element in a particularly simple manner, thereby particularly achieving a configuration in which the detent contour element is switched at a defined camshaft position, such that the complete switchover can be adapted to a cam profile of the brake cam and/or the firing cam.
The switchover device can also be in used in principle in conjunction with other valve operating mechanisms. For example, the switchover device can be designed for switching between partial load operation and full load operation, rather than for switching between a firing mode and a braking mode. It is also conceivable that the switchover device is designed for switching between a firing mode and a decompression mode, for example to increase comfort during a start and a stop of an internal combustion engine.
As a further idea of the invention, a valve operating device is therefore suggested, having at least one camshaft which comprises at least one cam group with at least one first cam and at least one second cam, having at least one cam follower functionally assigned to the first cam, which is provided for actuating at least one gas exchange valve in a first mode, and having a cam follower functionally assigned to the second cam, which is provided for actuating at least one gas exchange valve in a second mode, and having a switchover device which is provided to switch between the first mode and the second mode, wherein the switchover device is provided for the purpose of converting a torque of the camshaft into a force for switching between the first mode and the second mode. Further possible embodiments in this context particularly correspond to the dependent claims.
Additional advantages are found in the following description of the figures. The figures illustrate an embodiment of the invention. The figures, the figure description, and the claims contain numerous features in combination. A person skilled in the art will also expediently consider the features individually and combine them into additional, practical combinations.

Engine compression brake device for an internal combustion engine