A method for determining the safety of a gas mixture containing first and second flammable components together with non-flammable components, comprises using an optical detector to make at least two measurements influenced by the concentration in the gas mixture of the first and second flammable components. The percentage lower explosion limit of the gas mixture is calculated by a method based on the combination of the measurements. The method leads to acceptably accurate results, despite the presence of other flammable component(s) in the gas mixture.

Flammable gas concentration measurements are made in a number of safety-critical situations. One such flammable gas is natural gas, which typically comprises mainly methane, plus higher hydrocarbons, inert gases and trace components. Natural gas detectors are needed for a number of applications including response to public reported gas escapes and for continuous monitoring of plant/equipment using permanently installed detectors. They are required to measure the gas concentration as a percentage of the lower explosion limit (LEL) of the gas mixture, this being an important safety parameter.
The required accuracy of gas detectors is given by international standards. For example, European Standard EN 50057:1999 specifies that the instrumental accuracy of such instruments shall be no more than either ±5% of the measuring range (usually 0–100% LEL) or ±10% of the reading, whichever is the greater. Some published company standards demand an even greater level of accuracy. None of the published standards for natural gas leak detectors specifically addresses the issue of measurement errors that arise from compositional variation in the gas, and base their requirements on the error when the detector is faced with a consistent composition. However, it is desirable to meet the required standards of accuracy even with gas compositions of inconsistent composition.
While methane-specific detectors (ie detectors with no cross-sensitivity to any other gas) have been used for determining the safety of natural gas mixtures, such devices do not have the necessary cross-sensitivity to other flammable components and can give large errors.
The most extensively used detectors are based on pellistor sensors or flame ionisation technology. Pellistor-based sensors work by oxidising the gas mixture on a heated catalyst bead. This provides a measure of combustibility that is inherently related to the % LEL of the natural gas leak. However, there are a number of associated problems with these sensors when detecting natural gas leaks:    i) The cross-sensitivity to different flammable gases is not exactly what is required to compensate for their differing LELs. Correction factors must be applied if the sensor is used to measure a gas species different from the gas used to calibrate it.    ii) So-called "foldback" of the sensor response, in that, if the gas is present in concentrations sufficient to displace large quantities of oxygen from the air, the gas cannot burn in the detector and its response actually decreases as the gas concentration increases. This can result in ambiguity of the reading in safety-critical situations.    iii) A high cost of ownership resulting from a high maintenance requirement.
A number of gas-specific detectors, mostly based on specific detection of methane, have been developed to overcome these difficulties for natural gas applications. Many use optical detection of the gas, and in particular measure the optical absorption of the methane or other gases at specific wavelengths in the infrared region of the electromagnetic spectrum. Examples include European patent specification 874233 A2 (Siemens AG). Methane is chosen because it is the principal component of natural gas. However, the other components of natural gas cause errors in the resulting % LEL reading. Because these components have a varying composition, it is not sufficient to calibrate out the systematic error; the remaining random error is still too large to meet the demands of the detector standards mentioned above.

Method for determining the safety of gas mixtures


A method for authenticating a live person subject. The method includes receiving an authentication request from a user, generating a sequence of instructions instructing the user to point a face toward a sequence of facial directions, wherein the sequence of facial directions are randomly generated using a random sequence generation algorithm, presenting the sequence of instructions to the user, capturing, while presenting the sequence of instructions to the user, a sequence of live-captured facial images (LCFIs) based on a pre-determined frame rate, and generating an authentication result identifying the user as the live person subject by at least, matching the sequence of LCFIs to multiple reference facial images of the live person subject and validating each LCFI in the sequence of LCFIs based on a pre-determined criterion.

Facial recognition is an important part of any multi-factor identification system. Many existing arts in facial recognition algorithms analyze, in a learning phase, facial features of a reference facial image to obtain a set of reference attributes that positively identify the person subject of the reference facial image. The set of reference attributes is then compared with new facial features of a given facial image. The comparison result is then evaluated to determine percent of confidence in recognizing the given facial image and the reference facial image as being of the same person subject. Such prior art method may be used for user authentication by identifying a live-captured facial image of a user based on the user's pre-recorded reference facial image. However, this user authentication scheme can be defeated by an unauthorized user presenting a photograph of the authorized user to mimic the live-captured facial image.

Facial recognition to positively identify a live person subject


A thin film transistor and a method for fabricating the same are disclosed, in which an offset region is affected or biased by a gate voltage to increase on-current, thereby improving on/off characteristic of a device. A first semiconductor layer is formed on a substrate, and insulating layer patterns are formed at both ends of the first semiconductor layer. A second semiconductor layer is formed on the first semiconductor layer and the insulating layer patterns. A gate insulating film is formed on the first and second semiconductor layers and the insulating layer patterns, and an active layer formed on the gate insulating film.

1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, a thin film transistor and a method for fabricating the same.
2. Background of the Related Art
Generally, a thin film transistor is used as a CMOS load transistor or a load transistor in an SRAM cell of 4M or 16M. The thin film transistor is also used as a switching device for switching a picture data signal in each pixel region in a liquid crystal display device.
Particularly, an off-current should be reduced and an on-current should increase when a PMOS thin film transistor is used as the load transistor in the SRAM cell. For this reason, power consumption of the SRAM cell may be reduced and its memory characteristic is increased, thereby obtaining the SRAM cell of high quality.
FIG. 1 is a sectional view of a thin film transistor of the background art. The thin film transistor includes an insulating layer 21, a gate electrode 22a formed on the insulating layer 21, and a gate insulating film 24 formed on the insulating layer 21 including the gate electrode 22a. A drain electrode D is formed on the gate insulating film 24 at a predetermined distance from the gate electrode 22a, and a source electrode S is formed on the gate insulating film 24 to overlap the gate electrode 22a and spaced apart from the drain electrode D. A channel region I and an offset region II are formed on the gate insulating film 24 between the source electrode S and the drain electrode D. The offset region II is formed between the drain electrode D and the gate electrode 22a.
The method for fabricating the thin film transistor will be described with reference to FIGS. 2A to 2D. As shown in FIG. 2A, a first polysilicon layer 22 for a gate electrode of a bulk transistor is formed on the insulating layer or substrate 21. A photoresist is deposited on the first polysilicon layer 22 and then a mask pattern 23 is formed by exposure and development processes. Subsequently, the first polysilicon layer 22 is selectively removed by an etching process using the mask pattern 23 to form a gate electrode 22a, as shown in FIG. 2B.
As shown in FIG. 2C, a gate insulating film 24 is deposited on the insulating layer 21 including the gate electrode 22a. A second polysilicon layer 25 is then formed on the gate insulating film 24, which will be used to form the source and drain electrodes, an offset region and a channel region in the thin film transistor. Subsequently, a photoresist 26 is deposited on the second polysilicon layer 25 and then patterned by exposure and development processes.
As shown in FIG. 2D, a channel region and an offset region are defined by a photoresist pattern 26a of the patterned photoresist 26. Source and drain impurity ions or dopants are then implanted into the exposed second polysilicon layer 25 using the photoresist pattern 26a as a mask. Thus, a source electrode S is formed to partially overlap the gate electrode 22a and a drain electrode D is formed at a predetermined distance from the gate electrode 22a. The channel region I and the offset region II are formed between the source electrode S and the drain electrode D.
The above method for fabricating the thin film transistor has a problem that the on-current is small because the offset region is not affected by the gate voltage during the PMOS thin film transistor operation, thereby deteriorating reliability of the device.

Bottom-gated cylindrical-shaped thin film transistor having a peripheral offset spacer


A voltage-to-current converter circuit comprises an amplifier, a resistor, first and second feedback circuits, and an output circuit. The amplifier is configured to receive a differential input voltage signal. The resistor is coupled between first and second nodes of the amplifier. The first feedback circuit is coupled to a third node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a first range, and is turned off otherwise. The second feedback circuit is coupled to a fourth node of the amplifier, provides feedback to the first and second nodes when the value of the input voltage signal is in a second range different from the first range, and is turned off otherwise. The output circuit produces a differential current output signal having a value according to the value of the input voltage signal.

Voltage-to-current converters produce an output current according to an input voltage. In an ideal linear voltage-to-current converter, the output current is proportional to the input voltage. Voltage-to-current converters may have differential (positive and negative) outputs, wherein the difference between a current flowing through the positive output and a current flowing through the negative output corresponds to the output current, and the output current is proportional to an input voltage. Voltage-to-current converters may have differential inputs, so that the input voltage corresponds to a difference between a voltage provided to a positive input and a voltage provided to a negative input.
In many voltage-to-current converters, the conversion is accomplished using a degeneration resistor. A voltage corresponding to the input voltage is produced across the degeneration resistor, and the resulting current flowing through the degeneration resistor is used to produce the output current.
Voltage-to-current conversion is one of the key functionalities in RF transceiver design. For example, an up-conversion mixer of an RF transmitter may comprise a voltage-to-current converter, switches, and a load for the voltage-to-current converter, and the voltage-to-current converter may play the largest part in determining the overall performance and power consumption of the up-conversion mixer. Usually, the RF transmitter chain performance is strongly dependent on the up-conversion mixer performance. Accordingly, a highly-linear and highly power-efficient voltage-to-current converter design is one of the most important part of a high performance and power efficient RF transceiver design.
Voltage-to-current converters known in the related arts may operate in class A mode, so that current flows through both the positive output and the negative output regardless of the value of the input voltage. In a class-A mode device, transistors are biased so that current flows through them at all times, regardless of whether the input voltage is negative or positive. When the input voltage is a sine wave, this means that the transistors are biased so that current flows through them during all phases of the sine wave. This increases power consumption, because the transistors must be biased to have a large enough DC quiescent current that they are guaranteed to conduct current for any level of input voltage.
Other voltage-to-current converters may operate in class AB mode, wherein for some input values, current does not flow in some transistors of the voltage-to-current converter. However, these may require the degeneration resistor (or pair of degeneration resistors when the input to the voltage-to-current converter is differential) to be driven by the previous stage. Because the practical value of the degeneration resistor(s) may be limited (for example, on-chip resistors in a semiconductor device may by practically limited to tens or hundreds of ohms), this places a high load on the stage driving the voltage-to-current converter, resulting in higher power dissipation.
Accordingly, a need exists for more power-efficient linear on-chip voltage-to-current converters.

Linear class-AB voltage to current converter


An air pump has a casing, a motor assembly, a fan assembly, a faceplate and a sliding valve assembly. The motor assembly is mounted in the casing and has a motor. The fan assembly has a fan housing, an inlet manifold, an inlet plate and a centrifugal impeller. The centrifugal impeller is mounted rotatably in the fan housing and connects to the motor. The sliding valve assembly is hollow, is mounted slidably between the faceplate and the motor assembly and has a rear, a partition and an air passage. The partition extends into the sliding valve assembly. The air passage is formed between the partition and the rear. The air pump inflates when the air passage aligns with in the inlet manifold. The air pump deflates when the air passage aligns with the fan housing.

1. Field of the Invention
The present invention relates to air pump, especially to an air pump that can inflate and deflate without being disconnected and reconnected.
2. Description of the Prior Arts
Inflatable articles such as inflatable boats, inflatable pools, inflatable mattresses, etc. need to be inflated to be used. Inflatable articles are often large so using an air pump to inflate or to deflate them is quick and convenient. The inflatable article has an inflation hole for inflation and deflation. The conventional air pump comprises an air inlet, an air outlet, a fan and a motor. The motor rotates the fan, and the fan draws air into the air inlet and discharges air through the air outlet. When an inflatable article has to be inflated, the inflation hole in the inflatable article is attached to the air outlet of the conventional air pump. When the inflatable article has to be deflated, the inflation hole in the inflatable article is attached to the air inlet of the conventional air pump. Alternatively, the direction of rotation of the motor can be reversed so the air inlet functions as the air outlet and the air outlet functions as the air inlet when the fan is a propeller or vane-axial fan. However, reversing the rotation of the motor attached to centrifugal fans will likely be ineffective. Furthermore reversing the rotation of the motor may be more inconvenient than simply changing whether the air inlet or the air outlet is attached to the inflation hole.
To overcome the shortcomings, the present invention provides an air pump that can inflate and exhaust without changing contact or reversing motor to mitigate or obviate the aforementioned problems.


An antenna design for a tag operating in an radio frequency identification system minimizes the influence of reflecting surfaces upon the antenna radiation pattern. The antenna advantageously provides near uniform performance when the tag is in varying proximity to different metal reflecting surfaces. The antenna operates as a quarter wave patch antenna and is constructed from a rectangular metal patch separated from a larger metallic plane. This metallic plane serves as the reference ground plane for a circuit attached to the antenna, with a direct short between the patch and the ground plane along one edge of the patch. The dimensions of the metal patch are selected such that one quarter of a wavelength of incident radiation forms a standing wave on the antenna. A careful choice of dielectric material and lateral dimensions determine the bandwidth of the antenna. The presence of the ground plane serves as a natural advantageous plane of isolation between energy radiated from the patch antenna and otherwise reflecting surfaces which may be brought into proximity with this antenna.

Radio frequency identification (RFID) systems are used for identification and/or tracking of equipment or inventory such as pallets, trucks, dollies or boxes or even the whereabouts of some animals, such as livestock in certain situations. These RFID systems are radio communication systems in which communications is provided between a radio transceiver, or interrogator, and a number of small, identifying labels or tags. These tags are read while in the radiation pattern or field of the interrogator, which may be connected to a computer-based tracking system. The intent of an RFID system is to provide a reliable and secure architecture that meets a predetermined performance requirement, while minimizing the cost of the interrogator and the tags. In the operation of RFID systems, the interrogator transmits to the tags using modulated radio signals, and the tags respond by transmitting modulated radio signals back to the interrogator. Specifically, the interrogator first transmits an amplitude modulated signal to the tag. Next, the interrogator transmits a continuous-wave (CW) radio signal to the tag. The tag then modulates the CW signal using modulated back scattering (MBS) wherein the antenna is electrically switched, by the tag's modulating signal, from being an absorber of radio frequency (RF) radiation to being a reflector of RF radiation; thereby encoding the tag's information onto the CW radio signal. The interrogator demodulates the incoming modulated radio signal and decodes the tag's information message.
The performance of an RFID system and, more specifically, a tag within such system is influenced by its surrounding environment An antenna in the tag, which is optimized for operation without nearby reflectors or dielectric absorbers, will not perform as effectively when those influences are near. Thus, system performance and sensitivity can be strongly affected by variations in the environment.
Many antenna configurations have been proposed for use in tags that operate in RFID systems. Some of these configurations are described in the following U.S. Pat. Nos. 4,853,705 (Landt); 4,816,839 (Landt); 4,782,345 (Landt); 4,724,443 (Nysen); and 5,394,159 (Schneider). Most of these configurations are dipole antennas, or tapered antennas which radiate from both sides of a tag containing such an antenna. These radiation patterns are therefore significantly altered when the tag is placed in close proximity to a reflecting or absorbing surface. For example, Nysen, in U.S. Pat. No. 4,724,443, proposes a patch antenna that has a quarter-wave strip line feed element. However, this configuration is complex, expensive to fabricate, and requires three levels of metallization. Although Schneider, in U.S. Pat. No. 5,294,159, describes a patch antenna design with only two layers of metalization and also describes a technique to match the antenna to a demodulating circuit, Schneider is not concerned with the problem of how the performance of a tag is affected by its surrounding environment. It is therefore desirable to provide in a tag an antenna that produces a near uniform performance irrespective of variations in those environments in which the tag operates.


In an image forming apparatus, a supply roller 4 supplies a liquid developer to the photo-conductive substance of a photosensitive drum or belt prior to an electrostatic latent image forming process. The supply roller 4 is applied with a voltage dentical in polarity with the charge of toner in the liquid developer, and the liquid developer is uniformly supplied to the surface of a photo-conductive substance to form a liquid developer layer. An exposure unit 6 selectively exposes the photo-conductive substance from the upside of the liquid developer layer in accordance with the image information, to thereby weaken an adhesion of the toner in an exposed area of the liquid developer to the photo-conductive substance. A removing roller 8 is applied with a voltage opposite in polarity to the toner charge to attract and recover the toner weakened in the adhesion by an electric field. The developed image caused by the liquid developer which has remained on the surface of the photo-conductive substance without being recovered is transferred to a recording medium 11 by a transfer roller 13.

1. Field of the Invention
The present invention relates to an image forming apparatus and an image forming method using a liquid developer and a photo-conductive substance.
2. Description of the Related Art
A conventional image forming apparatus using a liquid developer electrostatically or magnetically forms a latent image on a surface of an imiage forming body using a photoreceptor or a dielectric substance which are photosensitive substances, or an image forming body such as a magnetic recording body, and then selectively adheres the liquid developer onto the latent image to develop the image. The image forming apparatus then transfers an image of the liquid developer (developed image) which has been developed on the surface of the image forming boy onto a recording sheet, and thereafter fixes the developed image as transferred on the recording sheet by heat. With this process, image formation is completed.
In the image forming apparatus of this type, there is used a developing unit for supplying the liquid developer to the image forming body on which the latent image has been formed to form the developed image. An example of the conventional developing mant of this type will be described. A developing unit which is disclosed in Japanese Patent Unexamined Publication No. Hei 2-306275 published in Dec. 19, 1990 supplies the liquid developer to a developing roller through a supply roller prom a vessel in which the liquid developer is accommodated to remove a surplus developer by a squeeze roller. A developing unit which is disclosed in Japanese Patent Urexamined Publication No. Hei 6-214466 published in Aug. 5, 1994 makes a photo-conductive substance mosve while a liquid toner vessel, a developing roller and a squeege roller ate brought close to a surface of the photo-conductive substance on which an electrostatic latent image has been formed in the stated order, to thereby form the electrostatic image into a visual image through a liquid toner.
Also, a developing unit which is disclosed in Japanese Patent Unexamined Publication No. Hei 2-277086 published in Nov. 13, 1990 includes a supply slit that is disposed opposite to an image forming body on which an electrostatic latent image has been formed and erects a liquid toner toward the image forming body, and a recovery slit that recovers a supply toner. Further, a developing unit which is disclosed in Japanese Patent Unexamined Publication No. Hei 4-233566 published in Aug. 21, 1992 includes a vacuum device for recovering an air and a liquid carrier which is disposed tightly close to a surface of a photo-conductive member with a gap therebetween before a developed image is transferred onto a sheet after an electrostatic latent image formed on the photo-conductive member has been developed by a liquid developer.
In the developing units of the conventional image forming apparatuses as described above, the liquid developer is selectively supplied toward the latent image in accordance with the electrostatic latent image which is formed prior to development, to thereby permit an image section to which the liquid developer is adhered and a non-image section to which no liquid developer is adhered to be formed. The conventional developing units of this type must be designed in such a imanner that a liquid toner (liquid developer) of the quantity with which a sufficient image density is obtained is supplied to the image section, but the liquid toner is not supplied to the non-image section for preventing an image noise from occurring. Thus, because the liquid developer must be selectively supplied, the conventional developing units get complicated in construction. Also, as disclosed in Japanese Patent Unexamined Publication No. Hei 4-233566, there is required an image noose evading unit such as She vacuum unit for recovering the surplus liquid toner after development with the result that a complication is more increased.
The use of the image noise evading unit makes not only the construction of the un.it complicated but also the size of the unit increase, which causes to the costs to be increased and the reliability to be lowered. On the other hand, in the case of using a dielectric substance for the image forming body, a latent image can be formed through one process by a linear electrostatic head, whereas in the case of using a photo-conductive substance such a photoreceptor, there is required a process for uniformly charging the photo-conductive substance before light exposure.
Further, the image -Lorming apparatus normally requires a cleaning section that cleans the surface of the image forming body in order to recycle an image carrier, and also as occasions demand, requires a removal section. Therefore, such an image forming apparatus is not economical in practical use.

Image forming apparatus and image forming method using selective exposure and removal of liquid developer


A strain relief for an insulation displacement connector contains an IDC with a cap having an entrance aperture and an exit aperture for passage of an electrical conductor and a companion strain relief pedestal located in close proximity to the IDC. The cap is slidably movable between a first position and a second position. The first position facilitates insertion of an electrical conductor through the apertures of the cap and the second position provides strain relief. One side of the pedestal, in cooperation with the IDC, defines a channel. When the cap is moved to the second position, the conductor is guided into the channel and retained at an angular orientation in the channel thereby providing strain relief for the connector.

Telephone lines, which are carried by electrical conductors known as tip ring wire pairs, are generally aggregated at a particular point in a building prior to being distributed and connected to various types of telephone equipment, such as, for example, telephones, fax machines, modems etc. As the tip ring pairs generally enter the building as part of a multi-conductor cable, the individual tip ring wire pairs must first be broken out from the cable into individual wire pairs. This is normally accomplished in a junction box known as, for example, a building entrance protector (BEP), or network interface unit (NIU). Within such devices the individual telephone line tip ring pairs are separated from the cable, individually connected to a connector block, and made available for further electrical connection and distribution. Usually there is a protector device inserted between the telephone and central office, or network side of the telephone line and the customer equipment or terminal side of the telephone line to protect the telephone and user, or other equipment connected to the telephone line, from hazardous overvoltages induced in the telephone network or in the cables passing between the telephone central office and the building within which the line is terminated.
In a typical arrangement, the telephone lines coming from the network are first wired to a protector field, which is an array of connectors for receiving the protector device, which is in turn hard wired to a first connector block which provides a first test point for testing the telephone line connections between the building and telephone central office. This first terminal block is hard wired to a multi pair connector, most typically a twenty-five pair connector of the RJ21 type, for further connection to an array of customer bridges which are also hard wired and connectorized via a mating RJ21 connector. The use of a customer bridge permits a subscriber to disconnect terminal equipment from a telephone line so that subscriber can isolate troubles on the line as originating in the telephone network, or on the terminal equipment side of the telephone line.
Additionally, there are known insulation displacement connector (IDC) blocks for use in such junction boxes and/or distribution fields, such as the ubiquitous punch down connector block, also known as a 66-type connector block, and the tool-less insulation displacement connector blocks utilizing push cap connectors, such as that described in U.S. Pat. No. 4,913,659 dated Apr. 3, 1990, the entire disclosure of which is incorporated herein by reference. Such a connector block is commercially available under the product designation SC99 from Lucent Technologies Inc.
The tip and ring wires held within such tool-less IDC connectors are strain relieved only to the extent held by the compressive force exerted by the IDC terminal holding the bare wire which has been stripped of its insulation layer. While this prior art IDC works for its intended purpose, a significant drawback to this prior art IDC is that when a pulling force is applied to the tip or ring wire, the wire is easily stripped and disconnected from the terminal. Thus, it is desirable to provide for a better strain relief mechanism for an IDC. Further, when conductors are passed through IDC caps in the prior art IDCs, the free end of the conductor which extends beyond the cap often needs to be cut off. The cut off portion often is very small, easily escaping into equipment or adjacent wire connector fields, increasing the risk of short circuits.

Base mounted strain relief for insulation displacement connector


A terminal connection (1) is provided that includes a threaded sleeve (2) and a counter sleeve (3) that can be connected to it, and a terminal insert that can be pressed against an elongated body (4). The connection has a coupling element (6) that can be detachably connected to the connection and includes a depression (7) and a passage (8) for the elongated body (4), and a radially protruding collar located on the threaded sleeve (2) fits and can be inserted into the depression (7). The coupling element (6) has radially inwardly directed projections (9) for engaging over the collar of the threaded sleeve (2) in the coupling position that are located on a front edge of the depression in the insertion direction of the threaded sleeve (2). The coupling element (6) has a fixing area (10) adjacent to the depression (7) for connecting to a counterpart or a retaining nut and/or through opening (11) of a housing (12), to which the terminal connection (1) is to be attached. This enables the elongated body to be connected in a fixed manner to a counterpart or housing prior to its fixation and to be subsequently mounted.

The invention relates to a terminal connection comprising a threaded sleeve, a counter-sleeve or a similar counterpart that can be connected to the threaded sleeve, and a terminal insert that can be pressed against an elongated body, such as a cable, tube, hose, rod, or the like, wherein the counter-sleeve or the counterpart exerts pressure on or covers the terminal insert with a ring-like contact surface at least on one of the ends and for tightening on a thread with a tapering shape, e.g., by means of rounding or a cone, which is arranged on the terminal insert, in the threaded sleeve, or instead of the ring-like contact surface on the counter-sleeve, an area of the terminal insert provided with slots or similar free spaces is deformed radially against the elongated body and wherein the threaded sleeve has a radially projecting collar or flange, whose peripheral contours are especially non-round or polygonal.
Such a terminal connection is known in several embodiments from EP 0 528 233 B1 and has proven to be effective. Above all, this known terminal connection is well suited for mounting, e.g., a cable on a through-opening of a housing, wherein the contact of the terminal insert on the cable is realized only when the terminal connection is mounted in the through-opening of the housing and the cable has been inserted.
However, there are cases, in which an elongated body, especially a cable, is already tightly connected to a terminal connection and only then should be mounted on a counterpart or housing through-opening. This means that the terminal insert is screwed on together with the elongated body held by it, e.g., with the help of a mounting section with thread, and thus the already clamped body must also be rotated.
Therefore, there is the problem of creating a terminal connection of the type mentioned in the introduction, with which an elongated body is already tightly connected before its mounting on a counterpart or a housing through-opening and then can be mounted later without having to turn the elongated body several times according to a screw motion.

Terminal connection comprising a threaded sleeve, a counter-sleeve and a terminal insert


Approaches for generating dynamic over-the-top (OTT) adjustable bit rate (ABR) representations of a video with a variable resolution and/or frame rate using on-the-fly (OTF) transcoding and assistance metadata. At an encoder located at a head-end, the encoder encodes a video stream at an initial bit rate and produces optimum representation (OpRep) metadata, which describes an optimum presentation for the video stream for each of a plurality of bit rates or the minimum bitrate below which a presentation becomes sub-optimal. The head-end transmits the encoded video stream and the OpRep metadata to a transcoder of a Content Delivery Network (CDN). The transcoder at the CDN uses the OpRep metadata to dynamically transcode the video stream in a preferred picture resolution and a preferred frame rate at a different bit rate than the initial bit rate using the OpRep metadata.

The trend of delivering and consuming video content over traditional IP networks continues to rise dramatically. This increase is in part due to the wide availability of VOD (Video On Demand) services and the multiplication of devices on which VOD content can be accessed. For example, video content may be accessed from various kinds of devices, such as smart phones, tablets, PCs, TVs, game consoles, and the like, which are connected through various types of networks (such as but not limited to broadcast, satellite, cellular, ADSL, and fiber).
Video content may be represented in different resolutions. Common resolutions available today include: 480i (720×480 pixels split in two interlaced fields of 240 lines), 480p (720×480 pixels), 576i (720×576 pixels split in two interlaced fields of 288 lines), 576p (720×576 pixels), 720p (1280×720 pixels), 1080i (1920×1080 pixels split in two interlaced fields of 540 lines), 1080p (1920×1080 pixels), 2160p (3840×2160 pixels), and 4320p (7680×4320 pixels). The resolutions 720p, 1080i and 1080p are generally referred as "HD" (High Definition) or "HDTV" (High Definition Television), and the resolution 1080p is more specifically referred as "Full HD" (Full High Definition). Resolutions 2160p and 4320p are generally referred to as "UHD" (Ultra High definition) or "UHDTV" (Ultra High Definition Television), 2160p may be referred to as "4K UHD" (4 kilo Ultra High Definition) and 4320p may be more specifically referred to as "8 k UHD" (8 kilo Ultra High Definition).
Due to the large size of raw video, video content is generally stored and accessed in a compressed form. The most widely used video standards belong to the "MPEG" (Motion Picture Experts Group) family, which notably comprises the MPEG-2, AVC (Advanced Video Compression also called H.264) and HEVC (High Efficiency Video Compression, also called H.265) standards. Generally speaking, the more recent a video compression format is, the more features and better compression ratio it provides. For example, the HEVC format is more recent and a more advanced compression format than AVC, which is itself a more recent and a more advanced compression standard than MPEG-2. HEVC yields more encoding features and greater compression efficiency than AVC, and the same is true between AVC in relation to MPEG-2. The compression standards of the MPEG family are block-based compression standards. Other block-based compression standards exist, e.g., the Google formats VP8, VP9, and VP10 and the AV1 format developed by the Alliance for Open Media (AOM).
OTT (Over-The-Top) video delivery aims at delivering video content for any user of an IP network. In OTT video delivery, a video is available in a number of different representations. A representation is a particular set of digital data which may be interpreted to display a video in a particular manner. For example, a representation for a video may describe characteristics of the video, such as its video resolution, its bitrate, its compression format, encoding options, and packaging. A representation typically identifies for particular packaging for video content, such as a file format and an extension, as devices are generally not able to parse all possible file formats.
When a client wishes to view a video from an OTT delivery platform, the client receives information about the available representations for the video of interest. Such information may be delivered to the client in a manifest file. The video is split into a succession of small files, referred to as segments, which are encoded in all available representations. The client may then download and play the small files, or segments, in the representation of interest to enable the client to play the video. When the bandwidth available to a client changes, the client may download subsequent video segments encoded at a bit rate appropriate for the available bandwidth.
It is common for network conditions to vary and for different devices to have access to different amounts of network bandwidth. This may be in part due to the location of the device, but there are many reasons why network bandwidth may change over time. The current conditions of the network do affect the quality of the video capable of being transmitted over the network, as higher quality video requires additional bandwidth for transmission.
The large diversity in the capabilities of clients, video compression standards, resolutions, and available bit rates are but some of the factors that lead to the large combination of possible video types and formats that must be supported to serve a wide range of customers by OTT delivery platforms.
Digital video is typically delivered over an IP network using a Content Delivery Network (CDN). A CDN is generally composed of a large number of servers. An origin or headend server is responsible for producing the video content, which then may be delivered across the network to clients that requested the video content. When a geographical region has a sufficient number of clients connecting to the CDN, an edge server is generally deployed to assist with providing service to that region. The role of the edge server is to receive the requests from clients in a particular region and redirect those requests to the headend server of the CDN. While clients in a region may send multiple requests for the same video content, the edge server need only send one request for the video content to the headend server; once the edge server possess the requested video content from the headend server, the edge server may deliver the video content to any client that requests the video content in the geographical region for which the edge server is responsible. This approach thus has the advantage of saving bandwidth within the CDN between the headend and the edge servers.
Recall that OTT video delivery aims to deliver video content to any user of an IP network. It is possible to achieve OTT delivery by encoding and packaging all possible representations of the video on the headend server and thereafter sending a requested video over the CDN to a client upon request. However, such an approach would undesirably saturate the bandwidth and the storage of the CDN. This is so because each representation that has been requested by at least one client would be sent throughout the CDN, which results in a large amount of data being transit through the CDN. This negative impact would be compounded by the necessity to store data at a server while the data is being delivered. Consequently, if a large number of representations are sent across the CDN, then it must follow that a large number of OTT files will be stored on the servers, and particularly at edge servers, during the delivery of the video. Such storage requirements introduce severe scaling and cost considerations.
An approach which may be employed to address this quandary is Packaging On-The-Fly (POTF) and Transcoding On-The-Fly (TOTF), also named Just-In Time Packaging (JITP) and Just-In-Time Transcoding (JITT). For applications such as a Network Personal Video Recorder (NPVR), only the highest resolution of the video in a single packaging is transmitted from the headend to the edge servers. Then, this video content is packaged and transcoded "on the fly," or dynamically upon request, at each edge server to another video format or resolution according to the needs of the edge server to satisfy client requests. This approach advantageously reduces the bandwidth consumption between the headend and edge servers as well as reduces the storage capacities of edge servers.

Assistance metadata for production of dynamic Over-The-Top (OTT) adjustable bit rate (ABR) representations using On-The-Fly (OTF) transcoding


An access performance adjusting method is adapted to a storage apparatus having a storage to prestore a skew quantity that is used to shift a data write starting position of each track of a recording medium depending on a head moving time required to move a head from one track to another track during a sequential access in which a plurality of tracks of the recording medium are accessed sequentially. The method includes measuring an apparatus performance with respect to a combination of the head and the recording medium, calculating a skew adjusting quantity with respect to the combination based on a reference apparatus performance and the measured apparatus performance, and adjusting the skew quantity read from the storage by the skew adjusting quantity and storing the adjusted skew quantity in the storage as an updated value of the skew quantity.

1. Field of the Invention
The present invention generally relates to access performance adjusting methods and storage apparatuses, and more particularly to an access performance adjusting method for adjusting a sequential access performance and a random access performance with respect to a recording medium, and to a storage apparatus which employs such an access performance adjusting method.
2. Description of the Related Art
In a magnetic disk apparatus which uses a magnetic disk having concentric tracks on which data are recorded, a sequential access is carried out to sequentially access a plurality of tracks. In order to carry out a data transfer at a high rate when carrying out the sequential access, the so-called "skew" technique is used. The skew technique shifts a data write starting position of each track depending on a time (hereinafter referred to as a head moving time) it takes to move a head from one track to another.
For example, suppose that the skew technique is not used and the data access starting positions of two mutually adjacent tracks are physically located along the same radial direction. In this case, when the access to the first track is completed and the head is to move to the adjacent second track, the head cannot move to the data access starting position of the second track in time, and it becomes necessary to wait for the magnetic disk to undergo one revolution. In other words, a wait time is generated. But when the skew technique is used, the data access starting position of the second track is shifted from the data access starting position of the first track in a circumferential direction by an amount corresponding to the head moving time, so as to reduce the wait time. When using the skew technique, the access performance is improved by reducing a data access delay caused by the wait time. Hence, an amount of skew, when converted in time, is set so that a minimum value becomes equal to the head moving time between two mutually adjacent tracks.
On the other hand, the magnetic disk apparatus uses a technique called "defective track avoiding process" to avoid defective tracks existing on the magnetic disk. When a defective track is detected on the magnetic disk, this defective track avoiding process avoids the defective track by preparing and using an alternate track on an inner peripheral side of the defective track, so as to maintain the total number of tracks constant among the magnetic disk apparatuses.
The recording density of the magnetic disk apparatus is increasing every year, and systems have been proposed to variably set the recording density, such as a Bit Per Inch (BPI) or a Track Per Inch (TPI) depending on the capabilities of the head and the magnetic disk. The yield of the magnetic disk apparatus can be improved by variably setting the BPI or TPI to an optimum value with respect to each combination of the head and the magnetic disk. However, when such a system is employed, the number of sectors within the track and the number of cylinders become different for each combination of the head and the magnetic disk and/or for each magnetic disk apparatus. The variable setting of the BPI or TPI is not made by the user, and is made when shipping the magnetic disk apparatus.
In the magnetic disk apparatus having the recording density, such as the BPI and TPI, that is variably set, the data transfer rate becomes different for each head and/or for each magnetic disk apparatus. For this reason, even among the magnetic disk apparatuses having the same storage capacity, there was a first problem in that the sequential access performance becomes greatly different among the magnetic disk apparatuses.
In addition, when the defective track avoiding process is carried out, the track that is used shifts towards the inner peripheral side of the magnetic disk. Consequently, if the defective tracks are frequently detected on a specific magnetic disk in the magnetic disk apparatus having a plurality of magnetic disks, a data storage location on the specific magnetic disk becomes greatly different from the corresponding data storage locations on the other magnetic disks within the magnetic disk apparatus. As a result, compared to the magnetic disks on which the defective tracks are not detected, the seek distance of the head with respect to the specific magnetic disk becomes longer. Accordingly, there was a second problem in that the random access performance with respect to an arbitrary track becomes greatly different among the magnetic disks within the magnetic disk apparatus depending on the number of defective tracks, and that the random access performance becomes greatly different among the magnetic disk apparatuses having the same storage capacity due to similar reasons.
Moreover, in the magnetic disk apparatus having the recording density, such as the BPI and TPI, that is variably set, the cylinder width at the time when one track is avoided becomes different for each head and/or for each magnetic disk apparatus, and the difference in the physical positions of the cylinders increases among the heads. Therefore, there was a third problem in that the random access performance becomes greatly different among the magnetic disk apparatuses, even among the magnetic disk apparatuses having the same storage capacity.
The first through third problems described above were not only generated in the magnetic disk apparatuses, but also in storage apparatuses having various kinds of recording media, such as optical disk apparatuses and magneto-optic disk apparatuses.

Access performance adjusting method and storage apparatus


A jig saw for more precise movement during cutting with a laser alignment system for projecting a marker onto a workpiece to align with a target line to be cut. The laser alignment system comprises a housing, a laser generator within the housing, an internal battery supplying the laser generator, a switch which is positioned within the housing and independent of the main switch to turn on and turn off the laser generator. By turning on the switch, the laser generator projects a laser beam onto the workpiece ahead of the blade in alignment with the plane of the blade. The operator only needs to align the projected laser line along a target line on the workpiece to attain the more precise cutting without concentrating his observation exactly ahead of the cutting blade.

The prior electric saw, particularly a jig saw, is mainly used to cut wood, steel plate, plastic and so on by a motor to reciprocate a saw blade. In order to align the saw blade with a cutting line on a workpiece, the operator must typically bring the blade into contact with the workpiece to determine if the saw is properly aligned with the cutting line. As is familiar to those skilled in the art, such a jig saw has some disadvantages. First, the operator is required to concentrate his observation exactly ahead of the cutting blade as the blade is pushed along the prescribed and prepared target line, it has to repeat this procedure several times in order to achieve proper alignment for precision, and this will result in waste of time and material. Also, the target line exactly ahead of the cutting blade may be covered by chip dust and influence the alignment of saw blade with the cutting line.


A method of planning a platform lift. The platform lift includes a rail, platform, chair, and a drive unit attached to the platform to drive the platform along the rail. The method includes acquiring 3D-data of a stair on which the platform lift is to be installed utilizing an augmented reality device. Calculating a travel path of the rail is based on acquired 3D-data and predetermined clearance information. Visualizing part or all of the platform lift is based on the calculated path of travel via the augmented reality device. Acquiring the 3D-data includes observing the stair with the augmented reality device; marking several locations and confirming the locations via a user input; extracting surface information via a computer based analysis of the markings and optical information taken by the augmented reality device. Based on the optical information and predetermined clearance information the path of travel is calculated.

The invention refers to a method of planning a platform lift, in particular a stairlift.
EP 1 554 210 A1 discloses a platform lift for the use of a disabled person in a wheelchair. WO 2013/129923 A1 discloses a platform lift in the form of a stairlift. In both cases the platform is part of a drive unit which travels along at least one guide rail. A leveling mechanism is provided to hold the platform always in a horizontal orientation, even if the inclination angle of the guide rail is changing along the path of travel. In particular the rail of such platform lifts has curved shape, like shown in FIG. 3 of WO 2015/052489 A1.
WO 2013/129923 A1 discloses a stairlift. The stairlift comprises a chair mounted on a drive assembly. The drive assembly travels along at least one guide rail. A leveling mechanism is provided to hold the chair always in a horizontal orientation, even if the inclination angle of the guide rail is changing.
In particular in small houses, where the stairs are narrow and/curved, the purchaser, which is later the user of the stairlift, cannot imagine, how the stairlift could fit into the stairs. It is often difficult to provide a real impression on the dimensions of the stairlift compared to the surrounding area of the stairlift merely from drawings or prospects. An additional problem is to deal with bottleneck areas or obstacles at the staircase.
Thus a need exists for a method of planning a platform lift, in particular a stairlift, at a stair, the platform lift comprising                a rail,        a platform, in particular a chair,        a drive unit for driving the platform along the rail,        the platform is attached to the drive unit.
In particular the method comprising the steps:                utilizing an augmented reality device;        acquiring 3D-data of a stair on which the platform lift is to be installed;        calculating based on the acquiring 3D-data and predetermined clearance information a path of travel of the rail;        visualizing at least parts (2, 6), in particular the rail (2) or the platform (6), of the platform lift (1) in accordance with the calculated path of travel (D) by means of the augmented reality device (13).

TK Elevator Innovation And Operations GmbH


The invention is directed to a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, wherein the clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission. According to one aspect of the invention, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement and has an actuating piston defining a pressure chamber for actuation, preferably for engagement, of the plate clutch arrangement by means of a pressure medium, preferably hydraulic medium, wherein cooling fluid, possibly cooling oil, can be supplied to the plate clutch arrangement from a cooling fluid supply, possibly a cooling oil supply, wherein the actuating piston, and also, if desired, a plate carrier, possibly an outer plate carrier, has at least one pressure compensation opening and/or cooling fluid outlet opening in a radial outer and/or central area.

1. Field of the Invention
The invention is directed to a multiple-clutch device, such as a double-clutch device, for arrangement thereof in a drivetrain of a motor vehicle between a drive unit and a transmission, wherein the clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission.
2. Description of the Related Art
A clutch device of this type is known, for example, from EP 0 931 951 A1. The clutch device serves to connect the drive of a motor vehicle with a multiple-speed shift transmission via two friction clutches which are preferably automatically actuated, wherein a disengagement or release system is allocated to each of these two friction clutches, so that the two friction clutches can be engaged or released independently from one another. A clutch disk of one of the two friction clutches is arranged on a central transmission input shaft so as to be fixed with respect to rotation relative to it, while a clutch disk of the other friction clutch engages at a second transmission input shaft so as to be fixed with respect to rotation relative to it, this second transmission input shaft, constructed as a hollow shaft, enclosing the central transmission input shaft. The known double-clutch is arranged with a fixed thrust plate of one friction clutch at a flywheel of an internal combustion engine. To this extent, the arrangement of the double-clutch in a drivetrain substantially corresponds to the arrangement of conventional (single)friction clutches in the drivetrain.
Double-clutch devices (called simply double-clutches) of the type mentioned above have attracted great interest recently and are generally formed of two wet or dry clutches which are switched alternately, possibly also with overlapping. Particularly in connection with a multiple-speed shift transmission, clutches of this type make it possible to carry out shifting processes between two respective transmission speeds of the transmission without interruption of tractive forces.
In principle, double-clutch devices make it possible for both clutches to be applied jointly in especially difficult starting processes, particularly those common in car racing. For this purpose, the accelerator pedal can be deflected to its stop, as the case may be, while the motor vehicle is kept essentially stationary at the same time by applying the maximum braking force until the clutch has reached its optimal transmission point. When the braking action is canceled at the moment of reaching the optimal transmission point, the vehicle is started with maximum acceleration. Starting processes of this kind are also considered for motor vehicles with a relatively weak engine under extreme starting conditions, for example, when starting on an obstruction; that is, they are not considered only for racing cars.
Obviously, starting processes of the type described above lead to high slippage with a correspondingly extensive development of heat. This presents the problem of carrying away this heat from the area of the friction clutch serving as starting clutch. Further, a correspondingly high wear of the friction clutch must be taken into account. Moreover, heating of the friction clutches is accompanied by changes in the coefficient of friction of the friction clutches, so that control of the release mechanisms of the two friction clutches, and therefore control of the two friction clutches relative to one another, can be appreciably impaired. Since inaccuracies or changes in the functional matching of the two friction clutches relative to one another caused by heat can have the result that a torque ratio not intended in the shifting process is applied to the transmission input shafts, shifting processes in the shift transmission can be subjected to load. The synchronization in the shift transmission can be overtaxed in this way, so that, in the worst case, the shift transmission can be damaged to the point of complete failure, apart from disadvantages with respect to efficiency which occur in any case. On the whole, mismatching between the two friction clutches caused by heat is incompatible with a problem-free torque transmission in shifting processes in the shift transmission without interruption of tractive force and without jerking during shifting.
Another problem area in a double-clutch device relates to starting processes carried out in opposition to an inclination, wherein the motor vehicle must be prevented from rolling backward, or those which are used when parking at the lowest possible speed, for example, for precise positioning of a motor vehicle in a parking space. The operating states mentioned above are referred to in technical circles as xe2x80x9chill-holdingxe2x80x9d and xe2x80x9ccreepingxe2x80x9d. Both starting processes have in common that the friction clutch serving as starting clutch is operated, sometimes without actuation of the accelerator, over a longer period of time with slip. Although the torques to be transmitted in such starting processes lie well below those occurring under the operating conditions described above, especially in car racing, an intensive heating of the respective friction clutch or even both friction clutches can occur, resulting in the problems detailed above.
Suggestions have been made for gear-shifting strategies and shifting processes for double-clutch transmissions based on the aimed for adjustment of clutch slip (DE 196 31 983 C1) with consequent generation of friction heat. Depending on driving behavior, overheating problems of the type mentioned above cannot be ruled out.
The risk of intensive overheating exists not only in a dry friction clutch, but can also occur in so-called xe2x80x9cwetxe2x80x9d friction clutches, possibly in the form of a disk or plate clutch, which are operated by the action of a viscous operating medium such as hydraulic fluid. By way of example, a gear change box with two plate clutches is known from DE 198 00 490 A1, wherein one plate clutch is provided for forward driving and the other for driving in reverse. DE 198 00 490 A1 is concerned primarily with providing adequate cooling of the two plate clutches using the viscous operating medium. In spite of the liquid cooling, heating of the friction clutches is also a considerable problem in plate clutches because the operating medium, which usually flows through friction facing grooves or the like to carry off the heat, cannot be guided between the plates in optimal quantity. The reason for this is that, on one hand, excessive flow through the friction facing grooves or the like would build up a counterpressure between the friction surfaces of two adjacent plates and would therefore reduce the capacity of the friction clutches to transmit torque (with a corresponding increase in slip and therefore additional generation of friction heat, so that the problem of overheating is exacerbated) and, on the other hand, the operating medium could be overheated and destroyed when flowing through between the plates. Overheating in plate clutches can result in that the friction surfaces can no longer separate from one another completely during a disengaging process and, consequently, torques can still be transmitted via the clutch which should be disengaged, so that considerable drag torques can reach the associated shift transmission. When plate clutches are used in a multiple-clutch device, especially a double-clutch device, of the type mentioned above, shifting processes could again be brought under load in the shift transmission with resulting overtaxing of the synchronization in the shift transmission.
One approach to mastering overheating problems in the area of friction clutches in case of unfavorable operating conditions, for example, with problematic starting processes in a motor vehicle, is to provide another starting element in addition to the first and second clutch arrangements which is in the form of a hydraulic clutch or hydrodynamic clutch and comprises a hydrodynamic circuit with an impeller wheel, a turbine wheel and, if desired, a stator wheel. The driving member can be connected in parallel with one of the two friction clutches; that is, it can act on a common transmission input shaft irrespective of the engagement state of this friction clutch. A clutch device in which two plate clutches and a starting element of this type are integrated, was described in the German Patent Application 199 46 857.5 by the present Applicants which was applied for on Sep. 30, 1999 and whose disclosure is incorporated in the subject matter disclosed in the present application.
Within the framework of investigations undertaken by the present Applicants in connection with double-clutch devices, it was shown in general that wet-type clutches exhibit sealing problems and problems relating to output losses. Further, it was shown that boundary conditions relating to the available axial and radial installation space could be adhered to only with difficulty, if at all, based on the previously known concepts. With regard to clutches, possibly, diaphragm clutches, which are actuated by pistons integrated in the clutch device, the arrangement of the piston chambers associated with the pistons proved especially problematic.
It is the object of the invention to achieve improvements with respect to at least one of the problems mentioned above and/or other problems.
According to a first independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement and has an actuating piston defining a pressure chamber for actuation, preferably for engagement, of the plate clutch arrangement by means of a pressure medium, preferably hydraulic medium, wherein cooling fluid, e.g. cooling oil, can be supplied to the plate clutch arrangement from a cooling fluid supply. According to the invention, it is further suggested that the actuating piston, and also, if desired, a plate carrier, possibly an outer plate carrier, has at least one pressure compensation opening and/or cooling fluid outlet opening in a radial outer and/or central area. The reason for this step is that when the only outlet provided for the cooling fluid is through the area of the plates a certain accumulation of cooling fluid in a radial outer area of the clutch device next to the actuating piston can hardly be avoided at least when larger amounts of cooling fluid are supplied to the at least one plate clutch arrangement, for instance, during slip states with corresponding heat development (for example, when starting). In this case, forces based on an interaction between the actuating piston and cooling fluid can then act upon the actuating piston, especially, for example, forces caused by centrifugal force or hydrodynamic forces. Considered in general, pressure differences can occur between the two sides of the piston for different reasons which impede the engagement and/or disengagement of the associated clutch arrangement. Such impairments of the actuating piston are prevented or at least appreciably reduced by the proposed step.
In order to ensure a sufficient flow of cooling fluid through the plates in spite of the possibility for cooling fluid to flow out through the pressure compensation opening and/or cooling fluid outlet opening, according to the invention, while circumventing the plates, a conducting element can be provided adjacent to the pressure compensation opening and/or cooling fluid outlet opening, which conducting element reinforces a flow of cooling fluid through the plates. A particularly advantageous and space-saving suggestion in this respect consists in that the conducting element is formed by an axial outer plate of the plate clutch arrangement having a fluid-conducting portion.
A particularly preferred construction is characterized in that the plate carrier and the actuating piston are alternately cut out in circumferential direction so that they can engage one inside the other such that, in at least one stroke position of the actuating piston, at least one area of the actuating piston that is not cut out engages in at least one cutout of the plate carrier preferably serving as a pressure compensation opening and/or cooling fluid outlet opening and/or at least one area of the plate carrier that is not cut out engages in at least one cutout of the actuating piston preferably serving as a pressure compensation opening and/or cooling fluid outlet opening. This construction is also advantageous regardless of whether or not at least one pressure compensation opening and/or cooling fluid outlet opening is provided according to the invention because it makes it possible to economize on axial installation space. However, the cutouts are generally open in both axial directions, that is, they are constructed as through-openings, so that the plate carrier and the actuating piston can engage in one another such that the one is penetrated by the other. The cutouts which are continuous in axial direction also compulsorily serve as pressure compensation opening and/or cooling fluid outlet opening.
The first clutch arrangement as well as the second clutch arrangement are preferably constructed as plate clutch arrangements. It is suggested for this purpose that a plate carrier of the first clutch arrangement having plates with a larger friction radius and an actuating piston associated with this clutch arrangement are alternately cut out in circumferential direction so as to allow the plate carrier and actuating piston to engage one inside the other and/or wherein a plate carrier of the second clutch arrangement having plates with a smaller friction radius and an actuating piston associated with this clutch arrangement are alternately cut out in circumferential direction so as to allow the plate carrier and actuating piston to engage one inside the other. This results in the above-mentioned advantages with respect to economizing on axial installation space, wherein it is suggested by way of further development for a particularly compact construction of the clutch device that the actuating piston of the first clutch arrangement and the plate carrier of the second clutch arrangement are alternately cut out in circumferential direction so that they can engage one inside the other such that, in at least one stroke position of the actuating piston, at least one area of the actuating piston that is not cut out engages in at least one cutout of the plate carrier, which cutout preferably serves as a pressure compensation opening and/or cooling fluid outlet opening and/or at least one area of the plate carrier that is not cut out engages in at least one cutout of the actuating piston, which cutout preferably serves as a pressure compensation opening and/or cooling fluid outlet opening.
In general, it is provided for this purpose that the mutual engagement is given for every stroke position of the respective actuating piston in order to prevent the actuating piston from rotating relative to the respective plate carrier. For this purpose, a defined rotational play can be provided between the respective piston and the respective plate carrier; however, the components mentioned above can also be carried out with respect to one another in such a way that no significant relative play can occur between them. For the sake of completeness, however, it should also be noted that it can be provided in general that the pistons can be rotatable relative to the plate carriers or that one of the pistons can be rotatable relative to an associated plate carrier or both plate carriers. The pistons or piston can then be used as a damping mass.
According to a second independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement, wherein cooling fluid, such as cooling oil, can be supplied to the plate clutch arrangement from a cooling fluid supply, wherein at least one wall which shields an interior space of the clutch device and which is arranged in a torque transmission path between an input side of the clutch device and an output side of one of the clutch arrangements has, in a radial outer area and/or central area, at least one pressure compensation opening and/or cooling fluid outlet opening. Unwanted effects which are mediated through the cooling fluid and might possibly interfere with the engagement and/or disengagement of the plate clutch arrangement can accordingly be prevented or reduced. The preceding remarks relating to the first aspect of the invention apply in a corresponding manner.
The wall can comprise a plate carrier, particularly an outer plate carrier, having at least one pressure compensation opening and/or cooling fluid outlet opening. Reference is had to the inventive suggestion according to the first aspect and the accompanying descriptions.
The inventive idea can also be applied to other parts of the multiple-clutch device, for example, to a wall portion which is used for transmission of torque between a plate carrier and an input side of the clutch device, such as a clutch device hub, and which, according to the invention, then has at least one pressure compensation opening and/or cooling fluid outlet opening and which is part of the wall. A conducting element reinforcing a flow of the cooling fluid through the plates can be provided axially adjacent to the pressure compensation opening and/or cooling fluid outlet opening of the wall portion. The conducting element can be formed by an axial outer plate of the plate clutch arrangement having a fluid conducting portion. A portion of the wall portion located farther outward radially relative to the pressure compensation opening and/or cooling fluid outlet opening can also come under consideration as a conducting element.
With respect to the pressure compensation opening and/or cooling fluid outlet opening according to the first or second aspect of the invention, it should be added generally that this portion of the actuating piston or plate carrier or wall which generally extends in radial direction can be provided so that cooling fluid can flow through the opening essentially in axial direction. The pressure compensation opening and/or cooling fluid outlet opening according to the invention is another opening in addition to openings which may possibly be provided in the plate carriers to enable a cooling fluid flow through the plate stack and contributes at most secondarily, if at all, to the flow of cooling fluid flowing through the plate stack.
According to a third independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that the first clutch arrangement and the second clutch arrangement are both constructed as plate clutch arrangements, wherein cooling fluid, such as cooling oil, can be supplied to the plate clutch arrangements from a cooling fluid supply, wherein a cooling fluid path to the plates of one of the clutch arrangements extends through at least one fluid passage opening in a wall portion of a plate carrier, possibly an inner plate carrier, of the other clutch arrangement, which wall portion connects a plate carrier hub with a plate retaining portion, and/or a fluid-conducting arrangement is provided for reinforcing a cooling fluid flow through a plate stack of at least one of the clutch arrangements.
According to this inventive idea, it is possible to supply both plate clutch arrangements with a sufficient quantity of cooling fluid, wherein it is also possible to supply a particularly large flow of cooling fluid to one of the two clutch arrangements which serves, for example, as a starting clutch or is operated with regulated slip, so that it must be ensured that friction heat is carried off in a particularly effective manner. This also holds true when a radial outer clutch arrangement of the first and second clutch arrangements surrounds a radial inner clutch arrangement annularly. In this case, it is preferred that the plate carrier having the fluid passage opening belongs to the radial inner clutch arrangement. A larger portion of the available cooling fluid can then flow past the inner clutch arrangement in order to cool the outer clutch arrangement in a particularly effective manner.
The fluid-conducting arrangement can contribute in an especially effective manner to ensure a sufficient cooling of the plates of the clutch arrangements. The fluid-conducting arrangement can comprise a conducting element which is formed by a plate of the respective plate clutch arrangement having a fluid-conducting portion. Further, it is suggested that the fluid-conducting arrangement comprises a wall which shields, at least in some areas, an interior space of the clutch device and which is arranged in a torque transmission path between an input side of the clutch device and an output side of one of the clutch arrangements. The wall can comprise a plate carrier, possibly an inner plate carrier, of the respective plate clutch device (whose plates are to be supplied with cooling fluid with the cooperation of the fluid-conducting arrangement) and/or of the other plate clutch device. Further, it is possible that the wall comprises a wall portion used for transmission of torque between a plate carrier and the input side of the clutch device. Other components of the multiple-clutch device can also perform a fluid-conducting function in the sense described above, for example, a wall of a pressure chamber, a wall of a pressure compensation chamber or even an actuating piston.
According to a fourth independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement to which cooling fluid, such as cooling oil, can be supplied by a cooling fluid supply, possibly a cooling oil supply, wherein a plate stack of the plate clutch arrangement has metal plates, such as steel plates, having no facing and plates having friction facings and an inner plate carrier and an outer plate carrier of the plate clutch arrangement are constructed for allowing at least one flow of cooling fluid to enter between plates of the plate stack from the radial inner side in such a way that, at least in one operating state of the clutch arrangement, the cooling fluid flows directly against steel plates having no facing and/or plates having a sintered facing and flows directly along the latter in radial outward direction.
It is achieved by means of the inventive suggestion that the plates which, because of the way they are constituted, absorb friction heat and store it temporarily depending on their heat capacity (plates with friction facings made of thermally insulating material, e.g., paper material, are capable of this only to a comparatively slight degree at best) and which consequently provide at least a majority of the available heat capacity interact with the cooling fluid so that this heat can be effectively absorbed by the plates and therefore guided away so that effective cooling is provided as a result. For this purpose, a passage opening of the inner plate carrier which overlaps an axial area occupied by the respective plate when the clutch arrangement is engaged can be allocated to the respective metal plate or the plate having the sintered facing against which the flow is directed. Alternatively, the passage opening can overlap the axial area occupied by the respective plate when the clutch arrangement is disengaged when a particularly effective dissipation of heat is to be effected by utilizing the heat buffer function of the plate in the disengaged state of the clutch arrangement. The passage opening preferably overlaps the axial area occupied when the clutch arrangement is engaged, as well as the axial area of the respective plate occupied when the clutch arrangement is disengaged, in order to provide for good heat dissipation in both states of the clutch arrangement.
At least one passage opening of the outer plate carrier can be allocated to the respective metal plate or the plate having the sintered facing, respectively, against which the cooling fluid flows; if desired, the passage opening is offset relative to the axial area occupied by the respective plate when the clutch arrangement is engaged and/or when the clutch arrangement is disengaged.
Generally, it is advantageous when passage openings in the inner plate carrier which are associated with different plates are offset relative to one another in circumferential direction and/or when passage openings in the outer plate carrier which are associated with different plates are offset relative to one another in circumferential direction. Every plate can then have at least one passage opening of sufficient size uniquely allocated to it in the respective plate carrier.
According to a fifth independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement to which cooling fluid, such cooling oil, can be supplied by a cooling fluid supply, wherein an inner plate carrier and an outer plate carrier and optionally further components of the plate clutch arrangement are constructed so as to allow at least a flow of cooling fluid to enter between plates of the plate stack from the radial inner side and flow out from the plate stack such that forces are exerted on the plates through the intermediary of the cooling fluid which act in favor of a disengagement of the plate clutch arrangement.
By reinforcing the release of the plate clutch arrangement by mediation of the cooling fluid, inertial forces which might oppose a quick release are more quickly overcome, so that the clutch device responds more quickly. This is advantageous, for example, when the plate clutch arrangement is operated with regulated slip.
The reinforcement of the releasing movement delivered by mediation through the cooling fluid is particularly advisable insofar as it frequently happens that the clutch arrangement can be released quickly (for example, as was mentioned, when the clutch arrangement is to be operated with regulated slip). Various factors can work against a quick release, for example, inertial forces which are exerted on the piston by a fluid coolant, especially cooling oil, or inertial forces which are mediated by the cooling fluid and act on the piston or which are based on the mass moment of inertia; as a rule, these inertial forces are particularly prominent when the piston releasing movement is introduced. For this reason, it is useful to reinforce the introduction of the piston releasing movement in the suggested manner above all.
In order to achieve reinforcement of the release of the plate clutch arrangement, a passage opening in the inner plate carrier and a passage opening in the outer plate carrier which allow flow through the plate stack can be offset relative to one another in such a way that the cooling fluid flowing through the plate stack is deflected in axial direction, preferably after the cooling fluid has flowed in radial direction between adjacent plates.
Forces acting in favor of a release of the plate clutch arrangement by mediation of the cooling fluid can be achieved, for example, in both of the following ways. Counterforces (reaction forces) occurring during the deflection of the cooling fluid can be utilized. Further, a drag effect of the deflected fluid can be utilized. The latter is preferred. For this purpose, it is suggested that at least the majority of the fluid flowing through the plate stack is deflected in the direction of an actuating piston of the respective plate clutch arrangement in order to achieve a drag effect of the fluid on the plates in the direction of the actuating piston and accordingly in favor of a release.
It is specifically suggested in this connection that at least one cooling fluid flow path passing the inner plates and the outer plates is provided radially between the inner plates of the plate stack and the outer plate carrier and/or radially between the outer plates of the plate stack and the inner plate carrier, wherein at least one axial positive flow of cooling fluid occurs predominantly in the direction of an actuating piston of the respective plate clutch arrangement * during operation when cooling fluid is supplied to the plate stack in order to exert a drag effect on at least some of the plates for releasing the plate clutch arrangement. In this regard, it is particularly useful when cooling fluid can flow out of the cooling fluid flow path in a first axial direction to an actuating piston and so as to pass an end plate on the actuating piston side and, when a cooling fluid flow path is provided radially between the outer plates of the plate stack and the inner plate carrier, preferably in addition to outlet possibilities, cooling fluid can flow in radial direction between adjacent plates of the plate stack and, when a cooling fluid flow path is provided radially between the inner plates of the plate stack and the outer plate carrier, if desired, in addition to outlet possibilities, cooling fluid can flow in radial direction through passage openings in the outer plate carrier. Further, it is particularly useful in this regard when cooling fluid can flow out of the cooling fluid flow path in a second axial direction opposed to the first axial direction to a counter-bearing which is associated with the actuating piston and at which the plate stack acted upon by the actuating piston can be supported, no cooling fluidxe2x80x94passing an end plate on the side of the counter-bearingxe2x80x94can flow out, or when only less cooling fluid can flow outxe2x80x94passing the end plate on the counter-bearing sidexe2x80x94than in the direction of the actuating piston so as to pass the end plate on the actuating piston side. The steps mentioned above, by themselves or in combination, cause any counterforces which act opposite to the drag effect of the fluid toward a release due to the deflection of the fluid (counterforces caused by the deflecting process itself) to dominate and cause forces which act on the whole toward a release to be exerted on the plates.
According to a sixth independent aspect of the invention, for a multiple-clutch device, such as a double-clutch device, for arranging in a drivetrain of a motor vehicle between a drive unit and a transmission, which clutch device has a first clutch arrangement associated with a first transmission input shaft of the transmission and a second clutch arrangement associated with a second transmission input shaft of the transmission for transmitting torque between the drive unit and the transmission, it is suggested that at least one of the clutch arrangements is constructed as a plate clutch arrangement having a plate stack in which plates which are associated with the drive unit and which are in a torque-transmitting connection or can be brought into a torque-transmitting connection with the clutch device via an input side of the clutch device can be brought into a frictional engagement with plates which are associated with one of the transmission input shafts and which are in a torque-transmitting connection or can be brought into a torque-transmitting connection with the clutch arrangement via an output side of the clutch arrangement, wherein cooling fluid, such as cooling oil, can be supplied to the plate stack by a cooling fluid supply, wherein at least some of the plates associated with the drive unit have flow passages which make it possible for cooling fluid to flow through the plate stack, generally from the radial inner side to the radial outer side, when the plates are in frictional engagement.
Since the plates having flow passages are provided on the drive unit side, these plates are driven in rotation continuously (or at least more frequently or for longer periods of time than the plates on the transmission side) when the drive unit is running. The revolving flow passages cause a feeding effect with respect to the cooling fluid, which leads to a better distribution of the cooling fluid in the plate stack and a continuous (or at least more regular) cooling fluid flow through the plate stack resulting in improved cooling action.
The flow passages preferably comprise passages which are formed by surface structures of a respective friction surface. For example, the plates associated with the drive unit can have friction facings which are formed of paper material or sintered material, if desired, wherein the passages can be constructed, for example, in the form of facing grooves or other surface structures. In general, it is suggested that flow passages are formed in the friction facings. The plates associated with the drive unit are preferably outer plates.
The features of a multiple-clutch and a drivetrain which were indicated in connection with the different aspects of the invention can be advantageously combined. Further independent aspects of the invention will be discerned by the person skilled in the art from the preceding explanations and the description of the Figures.
The invention is further directed to a drivetrain for a motor vehicle with a clutch device, according to at least one aspect of the invention, arranged between a drive unit and a transmission.
The invention will be described more fully in the following with reference to embodiment examples shown in the Figures.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.


A method for dynamically setting a scale for performing a cross-correlation check between a reference image and a comparison image of a mouse includes: setting a plurality of scale sizes for a cross-correlation check; providing a look up table (LUT) mapping the plurality of scale sizes to a plurality of overlapped areas of the reference image and comparison image and a plurality of predicted locations for the cross-correlation; determining a velocity of motion of the mouse, and using the determined velocity to generate a predicted location; inputting the predicted location to the LUT and mapping to a scale size; and performing the cross-correlation check according to the scale size.

1. Field of the Invention
The present invention relates to cross-correlation checking for a computer mouse, and more particularly, to a cross-correlation method for a computer mouse which can selectively adjust a scale size for performing a cross-correlation check.
2. Description of the Prior Art
A mouse is one of the most popular and commonly used input devices for a computer. A standard mouse comprises a wheel or an optical sensor, which is used to determine motion of the wheel/sensor relative to a 2-D surface, and then transform the motion into motion of a cursor or arrow on a display screen of the computer.
In order to detect the movement of an optical mouse, the optical sensor captures a first frame at a first time as a reference image, and captures a second frame at a second time as a comparison image, wherein the difference between the first time and the second time is equivalent to a frame rate period of the mouse. Cross-correlation is then performed between the reference image and the comparison image in order to determine the motion of the mouse during the time period between the two captured frames.
Please refer to FIG. 1, which illustrates an example of a reference frame and a comparison frame captured by a mouse moving at a particular velocity. In FIG. 1, the reference frame is illustrated by a 10×10 block filled in with diagonal lines sloping to the right, and the comparison frame is illustrated by a 10×10 block filled in with diagonal lines sloping to the left. As illustrated in the diagram, there is a certain offset between the two images, which is illustrated by the overlapped area having a crosshatch pattern. This overlapped area can be used to determine the distance the mouse has moved during the time period between the two captured frames. Cross-correlation can be performed for the entire two frames in order to determine the exact size and location of the overlapped area, but this is time-consuming, particularly when the mouse is moving at high speeds, as the size of the offset/overlapped area becomes smaller at higher speeds. Therefore, a limited amount of cross-correlation is performed between the two frames.
The mouse sensor navigation system thereby uses a location predicted to have the peak correlation as a predicted location which indicates where the cross-correlation should be centered. The predicted location corresponds to the accumulated delta of the mouse from frame to frame and is illustrated by the black dot in FIG. 1. The correlation process can be represented by the following equation:XC(r,c)wherein XC represents cross-correlation, and (r,c) represents the reference frame and comparison frame at their respective predicted locations.
If the predicted location is incorrect, the cross-correlation performed at the wrong predicted location will lead to an incorrect motion of the mouse will be reported. This incorrect reported motion will then be used as a basis for a next predicted location, meaning the next predicted location will also be incorrect. This may result in what is known as a runaway mouse situation, where the mouse is actually stationary but the cursor on the display screen continues to move.
To correct for the above-mentioned problem, conventional methods perform a cross-correlation check at the origin, i.e. location (0,0). A scale is applied to the cross-correlation, wherein the scale will have a constant value.
When the following condition is met:XC(0,0)*Scale>XC(r,c)it is determined that a runaway situation has occurred.
When the runaway situation occurs, the navigation process of the mouse needs to be reset. This involves clearing the predicted location and any unreported motion as well as re-capturing of a new reference image. A navigation reset therefore needs to take place before tracking can occur once more.
In some situations, however, the mouse may be moving in accordance with the cursor on the display screen, but the system will still falsely report a runaway situation. This is usually due to the scale being set too high for the cross-correlation check, which results in unnecessary clearing of both predicted location and any unreported motion. This false reporting will require resetting of the navigation process, which might produce a noticeable frozen cursor and can be annoying to a user. In extreme cases, resetting of the navigation process due to a false runaway situation might actually result in the mouse being unable to track. If, however, the scale for the cross-correlation check is set too low then it is difficult to detect a real runaway situation.

Dynamic scale for mouse sensor runaway detection