Described are a measuring method and a measuring tool for data communications networks which make use of asynchronous transfer mode (ATM). At the receiving-side 19.44 Mbit/s parallel port of ATM transmission devices, ATM cells are present, which are composed, for example, of 53 eight-bit width data words, whose 47 useful signal words (payload) originate from originally synchronous digital data strings, whose frequency is determined by the bit rate of the originally synchronous digital data strings, and which permit the cell-by-cell reading out of the payload data, which are fed consecutively and at a higher rate as burst data to a data test receiver, which can ascertain the correct or corrupted receipt of the transmitting-side data, without the need for a timing recovery circuit on the receiving side, so that the measurements can be performed using a constant bit rate and a variable bit rate of the originally synchronous digital data strings. The ATM measuring tool includes an ATM evaluation circuit (2), from which 47 payload data words are extracted from the 53 data words of each valid ATM cell and are fed with the aid of a 19.44 Mbit/s clocked write signal to the data inputs (d0 through d7) of a memory (3), and includes a clocked burst data generator (6), which in this case uses one eighth of the 19.44 Mbit/s clock pulse to control the reading out of the memory (3) and the parallel loading of the payload data words into a parallel-to-serial converter (4) and, moreover, emits a 19.44 Mbit/s burst clock pulse at the output (19). The converted serial data are supplied as clocked data to a burst-data output (5). Each data burst and the associated clock-pulse burst are emitted externally to outputs (18 or 19) and fed as a received signal to a data measuring receiver.

The present invention is generally directed to a measuring method and a measuring device for data communications networks which use asynchronous transfer mode (ATM).
ATM transfer systems are known, which are used to transmit synchronous digital signal strings, existing, for example, as digitized voice, digitized music, digitized images, or as a binary series of numbers, that have been split up into eight-bit-width data words and combined into packets; data packets of this kind are the payload of ATM cells. The AAL 1 format (ATM Adaptation Layer 1) is a customary cell format for transmitting synchronous data over ATM systems at a constant bit rate (CBR=constant bit rate). An AAL1 cell has 53 data words of eight bit length, i.e. 53 octets or bytes, of which five data words form the cell header, and another data word is used for numbering the data packet. 47 data words thus remain for the payload of the cell.
On the transmitting side, synchronous digital data strings are able to be easily converted into ATM cells. Since it is the transmission system, nowadays predominantly a fiber optic system of the so-called xe2x80x9csynchronous digital hierarchyxe2x80x9d (SDH) including the most frequently occurring STM1-interface, which predefines the transmitting bit rate of 155.52 Mbit/s, quite a few data systems employing the most frequently used synchronous transmission rate of 2.048 Mbit/s are able to be inserted into such an ATM transmission system. The individual 2.048 Mbit/s systems are distinguished by their individual cell header contents and can be reassigned later to the correct receiver.
Given a less than fully utilized transmission capacity over a 155.52 Mbit/s transmission route, it is possible to insert about 72 ATM cells of other users or idle cells into the gaps between two 2.048 Mbit/s payload cells of one specific data stream. Splitting the synchronous data stream into eight-bit words, as required in ATM cell formation, reduces the rate of the word clock or block clock in the processing and retransmission of signals at the parallel port to one eighth of 155.52 Mbit/s, resulting in 19.44 Mbit/s and facilitating the use of more highly integrated switch elements.
Greater difficulties have to be overcome on the receiving side to retrieve the original digital data string from the ATM cells of a specific data stream, because it is necessary to recover the synchronous data timing or clock. Clock recovery circuits require reference oscillators, whose frequency can be variably tuned within certain limits by the incoming line signal. VCOs (voltage controlled oscillators) are used to perform the variable tuning.
As long as the synchronous digital data strings continue to be transmitted at 2.048 Mbit/s, the receiver""s clock recovery circuit, equipped with an appropriate VCO, is properly set up for reconverting the incoming ATM cells. However, as soon as a lower or higher transmission rate is needed, for example in world-wide data communication traffic based on a customary, yet different, U.S. or Japanese standard, the variety of measuring methods is restricted by the availability of reference oscillators. Assuming it takes about eight weeks to acquire VCO modules to retrofit an ATM measuring instrument, a measurement could be delayed by this period of time, in the event of an urgently needed conversion.
An even greater problem is posed by payload measuring procedures when working with VBR data strings (VBR=variable bit rate), thus when the data that arise require a variable transmission rate. This is the case when working with MPEG encoded digitized television pictures, where the required transmission rate is a function of the changes in the differential-encoded picture content over time. Also the transmission of voice over ATM systems raises this measuring problem, because digitized voice transmission can occur with a transmission rate substantially lower than 2.048 Mbit/s.
Therefore, in the case of VBR data strings, the measuring procedure does well enough with ATM cell-oriented measuring methods; cell losses are registered using cell header data and mostly output as cell loss rates. However, ATM operating companies are obligated to transmit their customers""data and are asked about the quality of their networks with respect to these data. This customer data are inserted in the payload portion of the ATM cells. Therefore, a method for measuring the payload data is required, even when it is only a question of representing the time distribution of ATM cell losses in detail, cell for cell, to facilitate application of suitable error correction methods.
An object of the invention is to devise a measuring method and a measuring device for the asynchronous transfer mode used in telecommunications networks which functions without recovering the original synchronous data timing. This permits flexibility within the transmission rate of the synchronous customer data and that the measuring process also works with the variable bit rate of the original, synchronous digital data strings.
The present invention provides a measuring method for data communications networks which makes use of asynchronous transfer mode (ATM) for continuous payload measurements, particularly at a 19.44 Mbit/s parallel port of ATM transmission devices where ATM cells are applied. The cells in this case are composed of 53 eight-bit width data words, and whose 47 useful signal words (payload) originate from originally synchronous digital data strings, whose frequency (rate of occurrence) is determined by the bit rate of the originally synchronous digital data, and which permit the cell-by-cell reading out of the payload data. The payload data are fed consecutively and at a higher rate as burst data to a data test receiver, which is able to ascertain the correct or corrupted receipt of the transmitting-side data. The parallel data (DA0 through DA7) arrive together with a 19.44 Mbit/s block clock pulse (7) and a cell starting pulse (10) in an ATM cell evaluation circuit (2); in the evaluation circuit, the 47 payload words are extracted from the altogether 53 words of each valid ATM cell and are fed to data inputs (d0 through d7) of a memory (3). With the aid of a timed write signal (11), which is fed by the ATM cell evaluation circuit (2) to the memory input for the write signal (11), the 47 payload words are then read in one after another into the memory (3). The memory (3) indicates at which instant the cell contents are available and uses an empty flag signal (13) as a filling level indicator to start a clocked burst data generator (6), which is also timed by the block clock pulse (12). The generator uses the block clock pulse to produce different pulse bursts on separate lines (for example 14, 15, 16 and 19). With the aid of the first clock-pulse burst, the 47 payload words are read out one after another out of memory (3) and fed to the parallel inputs of a parallel-to-serial converter (4). This parallel-to-serial converter is supplied at its input (16) for shift/load signals with a specific number (in this case 47) of load pulses and, at its clock-pulse input (15), with clock pulses (in this case with eight times 47), which were produced as second and third pulse bursts. At a serial output (17), the parallel-to-serial converter relays, in the rhythm of the clock pulses, the payload data of an ATM cell to burst-data output (5), at a serial output (18) of the output (5).
Additional features or refinements of the present method include that the write signal (11) is clocked using the block clock pulse (7). The clocked burst data generator (6) is either likewise supplied with the block clock pulse (12) or, in an alternative embodiment, with a higher-rate block clock pulse via the clock-pulse supplier (20), with whose aid the clocked burst data generator (6) produces a specific number, in particular three different pulse bursts of the same duration. With the aid of the first clock-pulse burst, which is fed to the read-out control input (14) of the memory (3), the useful signal payload words (here 47) are read one after another via outputs (D0 through D7) out of the memory (3) and fed to the parallel inputs of the parallel-to-serial converter (4). In a manner suitable for the readout process, the parallel-to-serial converter (4) is supplied at its input (16) for the shift/load signals with corresponding load pulses (here 47) and, at its clock-pulse input (15), with a corresponding number (here with eight times 47) clock-pulses of the 19.44 Mbit/s clock pulse (12), which were produced as second and third pulse bursts by the clock-pulse burst generator (6). At its serial output (17), the parallel-to-serial converter (4) relays, in the rhythm of the clock-pulses, the payload data of an ATM cell to burst data output (5), and these data bursts and clock-pulse bursts (here 376 bit long) represent, ATM cell for ATM cell, consecutively, the originally synchronous transmitting measuring data, and are compared in the measuring receiver on a bit by bit basis to a synchronizable reference signal, and are continually supplied as a comparison result to the designated result protocol.
Another refinement includes that, to increase the clock-pulse of data being output to output (19), a higher-rate block clock-pulse supplier (20) is provided. The memory (3) indicates at its output (13) when cell contents are available, and starts clock-pulse burst generator (6), which works with the increased block clock-pulse of, for example, 42.0 Mbit per second, resulting in the generation of three different pulse bursts of the same duration, here, namely, a burst having 47 pulses in 5.25 Mbit/s rhythm on read line (14), a clock-pulse burst having eight-times 47 pulses in the 42.0 Mbit/s rhythm to input (15), and a pulse burst clocked in a 42.0 Mbit/s rhythm as load/shift signal to input (16) of the parallel-to-serial converter (4). The transmission rate within the output bursts may be increased from 19.44 to 42.0 Mbit/s; and only a time period of three idle cells may still be needed as a gap between the two valid ATM cells at the parallel port for switching on the ATM measuring tool (1), so that the originally synchronous transmitting-side transmission rate rises to maximally 35 Mbit/s. Alternatively, by using a fast-action switching circuit technique, such as ECL, for the parallel-to-serial converter (4), the clock-pulse burst generator (6), and the burst data output (5), one increases the transmission rate within the output burst from 19.44 to over 140 Mbit/s; then no gap exists between two valid ATM cells at the parallel port for switching on the ATM measuring tool (1), and as a result, the originally synchronous transmitting-side transmission rate rises to maximally 140 Mbit/s.
A still further refinement of the present method is that the measuring tool (1) is switched on at a point on the transmission route where the ATM data signals are available in 8-bit parallel, with a cell starting pulse signal (10), an 8-bit block clock pulse and, in some instances, with an idle cell identifier, or an identifier for the valid cells. At the output of the memory (3), the 8-bit data words are read out with one eighth of the block clock pulse and supplied to the parallel-to-serial converter (4), to be read out there serially using the block clock pulse. For each valid ATM cell, a data burst of the length of the number of payload bits contained therein and, matching this, a block clock-pulse synchronous clock-pulse burst of the same length is emitted by a clock output circuit (6). The synchronous data/clock bursts are supplied from the ATM measuring tool (1) to the data/clock-pulse inputs of a data measuring receiver.
The present invention also provides a measuring tool or device, in particular for implementing the present method, wherein parallel data (DA0 through DA7), a block clock pulse (7), a void cell identifier signal (8), and an identifier for valid cells (9) are switched to the input of an ATM cell evaluation circuit (2). The output of the ATM cell evaluation circuit (2) is linked to a memory (3) and via a block clock-pulse supplier (12) to a clock-pulse burst generator (6). Connected in outgoing circuit to memory (3) is a parallel-to-serial converter (4), which is timed and controlled (15 and 16) by clock-pulse burst generator (6) and which, in turn, is linked by its output (17) to a circuit of a burst-data output (5), at whose serial output (18) data are adapted to be tapped off for the data measuring receiver. Clock-pulse burst generator (6) receives an empty flag signal (13) from memory (3), and is linked to the input (16) of the serial-to-parallel converter (4) for the shift/load signal, as well as emits externally via the clock-pulse burst output (19) clock-pulse bursts matching the data, to the data measuring receiver.
Advantageous refinements include: (a) that to read the memory (3), the memory is linked to a clock-pulse (20) having a higher rate than the eighth clock pulse, enabling the time interval between two successive, valid ATM cells to be less than seven idle cells; (b) that the measuring tool is implemented using integrated circuit technology; (c) the measuring tool (1) is part of an ATM measuring instrument; and (d) the measuring tool (1) is part of a data measuring instrument.
According to the present invention, the received data, which are contained in each ATM cell and come from the original, continuous, synchronous digital data string, are able to be supplied at a higher rate and as bursts of data to the data measuring instrument, so that one can dispense entirely with the difficult clock recovery, since the data measuring instrument used here is suited for such a burst transmission operation. The measuring device fits on the receiving-side 19.44 Mbit/s parallel port of ATM transmission devices. It is there that ATM cells are applied. The ATM cells are composed of 53 eight-bit width data words, whose 47 useful signal words (payload) originated from originally synchronous digital data strings, whose frequency is determined by the bit rate of the originally synchronous digital data strings, and which permit the cell-by-cell reading out of the payload data. The payload data are fed consecutively and at a higher rate as burst data to a data test measuring receiver, which can ascertain the correct or corrupted receipt of the transmitting-side data without the need for a clock recovery circuit on the receiving side. Thus, measurements can be performed not only using a constant bit rate, but also with a variable bit rate of the originally synchronous digital data strings.

Measuring method and measuring device for data communication networks


An electromechanical steering device for a motor vehicle having at least one electric motor and power electronics for controlling the electric motor includes at least one temperature sensor for measuring the temperature of the power electronics and/or the ambient temperature of the power electronics and switching times of the power electronics are variable as a function of the measured temperature.

The invention relates to an electric motor-supported steering system.
The term electric motor-supported steering devices includes active steering systems in which an electric motor has a driving action on a differential drive in order to superimpose a steering movement on the steering movement initiated by the driver depending on the driving situation. Such a steering device is known for instance from DE 39 08 217 A1. Furthermore, the aforesaid preamble also includes steering devices in which the task for the electric motor is merely to support the steering movement initiated by the driver by making available auxiliary steering force. In such steering systems, the electric motor is frequently drivingly connected to a rack of a steering gear.
The electric motors, embodied for instance as synchronous or asynchronous motors, are controlled using power electronics with a frequency converter. It converts the supply voltage from the vehicle onboard electric system to a plurality of clocked pulse-width modulated signals with frequencies in the 20 kHz range. The mean of the pulse-modulated signals is set such that the motor current desired depending on application is set via the inductivity of the electric motor. Depending on application, the motor current can be for instance sinusoidal or rectangular. The power electronics contains a plurality of power transistors. The switching processes performed thereby necessarily result in the transmission of interfering signals that affect electromagnetic compatibility (EMC). These are conducted for instance via the lines to the electric motor, the battery line for the steering device, and other electric connections on the steering device and there cause interfering emissions. In addition to the direct interfering emissions, there is overcoupling onto other lines in the motor vehicle and this causes further interfering emissions and/or galvanic interfering transmission to the onboard electric system.
Minor EMC interference results from long switching times, that is, from long control voltage rise and/or fall times and/or from long control current rise and/or fall times for building up and reducing the capacities of the power electronics or power transistors, but the power loss in the power electronics during long switching times is great, which can lead to the power electronics heating up sharply and thus in extreme cases to a functional failure of the power electronics and thus of the electric motor. When dimensioning the control of the electric motor, the switching times are set or established as slow as is permissible for a theoretical maximum ambient temperature or maximum power electronics temperature. That is, the design is based on the maximum permissible power loss and thus the maximum permissible heating at a theoretical maximum temperature.
The underlying object of the invention is to improve the EMC in a steering device.

Electric motor assisted steering apparatus


A radio communication device comprises an upper housing and a lower housing connected by a hinge part to be mutually rotatable. A connection portion electrically connects a first circuit board in the upper housing and a second circuit board in the lower housing each other. An antenna is provided in the lower housing and has a base, an electric supply terminal and a ground terminal. An antenna electric supply part is provided to supply an operating current from the second circuit board to the antenna. A position of the antenna electric supply part is shifted from a central position of the second circuit board in an axial direction of the hinge part to increase a distance from the connection portion, and the electric supply terminal and the ground terminal are extended from the antenna base in the hinge part axial direction to contact the antenna electric supply part.

1. Field of the Invention
The present invention generally relates to a collapsible type radio communication device in which the antenna is built in the interior of the housing, and the upper housing and the lower housing are connected by the hinge part so that they are mutually rotatable.
2. Description of the Related Art
In a collapsible type portable telephone which is a kind of the structure of the portable telephone, the upper housing and the lower housing are connected by the hinge part so that they are mutually rotatable around the hinge part. The collapsible portable telephone is provided so that the upper housing can be opened and closed to the lower housing.
The portable telephone of the collapsible type provides the advantageous features in that the upper housing can be equipped with a large-sized display screen, that the composition when the upper housing is opened makes use of the telephone easy, and that the slim structure when the upper housing is closed to the lower housing is convenient to carry.
In a conventional portable telephone of the collapsible type, the projection type antenna arranged in the lower housing or the projection type antenna arranged in the upper housing is used.
Generally, the helical antenna or the extendable monopole antenna is used as the projection type antenna, and the antenna portion projects from the housing. The projection type antenna provides the advantageous feature in that the antenna gain can be made high in a condition that the user holds the portable telephone by hand.
However, with the projection type antenna, there is the problem that the antenna portion projecting from the telephone housing is obstructive when taking out the portable telephone from the user's pocket on the occasion of use.
On the other hand, as the antenna built in the housing of the collapsible portable telephone, the strip line antenna and the hinge-part built-in type antenna are known. Moreover, the flip-part built-in type antennas, such as the coil-like antenna and the micro strip line antenna, are also known.
Since there is no portion which projects from the housing according to such built-in antennas, the problem like the problem of the projection type antenna does not arise with such built-in antennas.
For example, Japanese Laid-Open Patent Application No. 2003-008320 discloses a collapsible portable telephone which uses the hinge-part built-in type antenna.
In this portable telephone, the hinge-part built-in type antenna is arranged at a position which is adjacent to the hinge part connecting the upper housing and the lower housing, and overlaps the upper part of the flexible wiring board.
FIG. 1 shows the outline composition on the front side of a conventional portable telephone. FIG. 2 shows the outline composition on the back side of the conventional portable telephone.
As shown in FIG. 1 and FIG. 2, the conventional portable telephone 1 is of the collapsible type, and comprises the upper case 2 and the upper cover 11 which attach the display unit, such as the liquid-crystal-display unit, to the upper case surface, the lower cover 4 and the lower case 12 which attach the key operation unit including ten keys, various function keys, etc., to the lower case surface, and the hinge part 3 and the hinge part 5 which connect the upper case 2 and the lower cover 4 to be mutually rotatable around the hinge parts.
By assembling the portable telephone 1, the upper case 2 and the upper cover 11 form the upper housing of the portable telephone 1, and the lower cover 4 and the lower case 12 form the lower housing of the portable telephone 1.
The upper housing circuit board 6 for attaching the various electric parts including the display unit is provided in the upper housing of the portable telephone 1, and the back surface (for the sake of convenience, the surface shown in FIG. 2 will be called the back surface) of the upper housing circuit board 6 is protected by the upper cover 11.
The lower housing circuit board 7 for attaching the various electric parts including the key operation unit is provided in the lower housing of the portable telephone 1, and the back surface (the surface shown in FIG. 2 will be called the back surface) of the lower housing circuit board 7 is protected by the lower cover 4.
The hinge part 3 is formed integrally with the upper case 2, and the hinge part 5 is formed integrally with the lower cover 4. Moreover, the hinge parts are formed integrally with the upper cover 11 and the lower case 12, respectively. The upper cover 11 and the lower case 12 are provided so that they are mutually rotatable around the hinge parts. Therefore, the upper housing and the lower housing are provided so that they are mutually rotatable around the hinge parts.
The flexible wiring board 8 electrically connects the upper housing circuit board 6 and the lower housing circuit board 7 each other, and is arranged to extend from the upper housing circuit board 6 to the lower housing circuit board 7 through the hinge part 5.
The flexible wiring board 8 is formed of a flexible member. In order to accommodate the flexible wiring board 8 in a small space adjacent to the hinge part between the upper and lower housings, the flexible wiring board 8 is arranged in the state where it is wound once or more around the hinge part 5 in the middle of the flexible wiring board 8.
The antenna electric supply part 9 is arranged at the end of the lower housing circuit board 7 near the hinge part 5, generally in the center of the lower housing circuit board 7 along the axial direction of the hinge part.
The antenna 10 is provided at the end of the lower housing adjacent to the hinge part 5. The antenna 10 is formed of a sheet metal, and it is formed in a predetermined form so that sufficient antenna gain may be obtained.
The antenna 10 is arranged in the position contiguous to the flexible wiring board 8 in the lower case 12 so that the electric supply terminal and ground terminal which are prolonged from this antenna 10 may contact the antenna electric supply part 9.
The antenna 10 operates by the operating current supplied through the electric supply terminal from the antenna electric supply part 9 of the lower housing circuit board 7, and functions as an antenna for transmission and reception.
With the progress of the multiple functionality in the recent portable telephones, it is desirable to make the display unit of the upper housing as large as possible, and the key operation unit of the lower housing has restrictions in that it cannot be made much smaller from the viewpoint of operability.
Moreover, in the portable telephone of this kind of collapsible type, since it tends to be bulky when the thickness becomes thick as a whole and the upper housing and the lower housing are put into the pocket etc. in the state where it closed focusing on the hinge part, since the upper housing and lower housings overlap mutually, the slim structure of the portable telephone is desired.
On the other hand, the number of wirings, such as signal wires in the respective circuit boards provided in the upper and lower housings, tend to increase by the multiple functionality of the portable telephones, and adoption of the big drop of size.
Therefore, it is in the tendency for the numbers of wiring, such as signal wiring accommodated in the flexible wiring board formed in order to connect between the circuit boards of the upper and lower housings, to also increase.
Securing the increased number of wirings of this circuit board will bar the slim structure of the portable telephone of the collapsible type. That is, in order to satisfy the demand of thin structure, there are restrictions that width of the flexible wiring board of the securable for the internal space of the circuit board of the upper and lower housings can seldom be enlarged.
Moreover, in order to accommodate much signal wiring, when unavoidable, in order to have to form two or more flexible wiring boards in the space inside the upper and lower housings in piles, the subject that the slim structure of the portable telephone becomes difficult occurs.
FIG. 3 and FIG. 4 show the composition by the side of the surface of the conventional portable telephone in the state where it is folded down, and the back.
FIG. 5 shows the outline composition when removing the lower case in the portable telephone of FIG. 4.
As shown in FIG. 3, in order to accommodate the winding portion in the middle of the flexible wiring board 8 in a small space near the hinge part between the upper and lower housings in the conventional portable telephone 1, there are restrictions that making the width (indicated by the arrow B1 in FIG. 3) of the flexible wiring board 8 in the hinge part axial direction so much large is not allowed.
Moreover, the flexible wiring board 8 needs to be arranged so that it may not interfere with the antenna electric supply part 9 of the lower housing circuit board 7.
As shown in FIG. 4, the antenna 10 is arranged in the position contiguous to the flexible wiring board 8 in the lower case 12 so that the electric supply terminal 13 and the ground terminal 14 which are prolonged from the antenna 10 may contact the antenna electric supply part 9 of the lower housing circuit board 7.
As shown in FIG. 5, the electric parts which affect the antenna property at the time of operation of loudspeaker 15 grade besides the electric parts of the key operation unit are also attached in the lower housing circuit board 7.
The form of the antenna 10 which includes the pieces of metal, such as the copper and the aluminum, makes as small as possible influence which it has on the property of the antenna 10 by the electric parts on the lower housing circuit board 7, and it needs to be constituted so that sufficient antenna gain may be obtained.
Moreover, in consideration of the property of the antenna 10, it is necessary to opt for arrangement of the antenna electric supply part 9 in the lower housing circuit board 7.
As mentioned above, the number of wirings of the wiring circuit board carried in the portable telephone is in the tendency to increase in recent years, so the number of wirings of the flexible wiring board 8 also tends to increase. On the other hand, however, there is also the demand for the slim structure of the portable telephone.
In the conventional portable telephone of the collapsible type, in order to satisfy the demand for the slim structure, the problem in that it is difficult to take a large width of the flexible wiring board that can be provided in the internal space of the wiring circuit boards of the upper and lower housings arises.


In a solid-state image sensing device, a second substrate having transparency, including a via is placed on a solid-state image sensor having a pixel region and a logic region formed in a first substrate and in which a passive component electrically connected with the solid-state image sensor through the via is mounted on the second substrate. Thus, highly efficient location of passive components is attained for miniaturization.

1. Field of the Invention
The present invention relates to a solid-state image sensing devices used as, for example, camera modules for a digital still camera, a mobile phone and the like.
2. Description of the Related Art
In recent years, with the miniaturization of digital still cameras and mobile phones, the miniaturization of camera modules installed therein is required.
Generally in a camera module, as disclosed in FIG. 2 and [0029] to [0037] of Japanese Patent Application Laid-Open Publication No. 2005-244118, a solid-state image sensor (sensor chips), such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide semiconductor), and a passive component including a passive element such as a capacitor are mounted on printed circuit boards such as flexible substrates. Further, optical elements such as an optical filter and a lens are mounted on the flexible substrates to constitute a camera module.
In this case, passive components are generally arranged around a solid-state image sensor. Accordingly, the area of the camera module depends upon an area occupied by the passive components. Generally, a plurality of passive components are required for one solid-state image sensor so as to make it work as a solid-state image sensor. Accordingly, it is difficult to miniaturize digital still cameras and mobile phones by reducing of the camera module area since the number of passive components cannot be decreased.


Fixed electrodes (A through F) are formed by means of a structural layer that has been provided on fixed bodies (7.sub.1 through 7.sub.4) of a silicon micro-machined substrate and a movable electrode (G) is formed by a movable body attached to fixed bodies (5.sub.1 through 5.sub.4) by flexible members (6.sub.1 through 6.sub.4). Variable capacitors of the parallel plate-type are formed by the movable electrode (G) and the fixed electrodes (A through F). When the movable electrode (G) has been vibrated, the Coriolis force incident to rotation or the force incident to acceleration are added to the movable electrode (G), with a result that the charge of the various variable capacitors change. By detecting the change in charge, both angular velocity and acceleration can be obtained. By providing another variable capacitor formed by a mass portion (H) by a movable body and the substrate, acceleration components in the directions of three axes can be detected.

This invention relates generally to a composite sensor which detects acceleration or angular velocity and in particular to a composite sensor that has been constructed by micro-machining silicon.
Some composite systems combining an acceleration sensor and an angular velocity sensor have been made public recently. One of the representative systems pertains to an automobile attitude control, commonly called VDC (vehicle dynamic control) or VSC (vehicle stability control). These composite sensor systems are used in the comprehensive control of the movement of automobiles by the adjustment of brake pressure of individual wheels for the purpose of preventing over or under steering at the time of rotational movement of the vehicle. For such a purpose, a two-axis acceleration sensor and a one axis angular velocity sensor are deemed to be essential.
Navigational systems of automobiles have quickly become popular in recent years. In such systems, the signal of wheel velocity, etc., as received from the automobile itself, is used in the calculation of the running distance of the automobile. However, the connection for signal reception is troublesome and as a result there is a demand for a stand alone system. Therefore, a navigation system has been proposed for accurately knowing the position of an automobile by detecting the change in direction of its progress at an intersection or a curve by means of an angular velocity sensor and by determining the running distance by means of an acceleration sensor, thereby accurately knowing the position of the automobile. An angular velocity sensor and an acceleration sensor which are used in a composite sensor according to the prior art will be explained briefly by referring to the attached drawings.
With reference to FIG. 9, reference numeral 102 indicates a conventional angular velocity sensor having a metallic body 103 in the shape of a rectangular parallelepiped. Piezoelectric bodies 104.sub.1 and 104.sub.2 are provided on metallic body 103 on two respective sides normal to one another.
Angular velocity sensor 102 is arranged so that a moving body with a rotary axis 105 forms the Z axis in the case where the normal lines of the vibration surface of the piezoelectric bodies 104hd 1 and 104.sub.2 are made along the X axis and Y axis respectively, as shown in FIG. 9(A).
In the case where piezoelectric body 104.sub.1 is set as the driving side and piezoelectric body 104.sub.2 is set as the detection side, if an alternating current voltage is impressed on piezoelectric body 104.sub.1 on the driving side, thereby vibrating it in the X axis direction as is shown in FIG. 9(B), the rotary movement of the moving object in which the sensor is mounted produces a Coriolis force, thereby generating a vibrating force in a direction (the Y axis direction) which crosses, at a right angle, with the direction of vibration of piezoelectric body 104.sub.1 on the driving side. Its vibration is transmitted to metallic body 103 and piezoelectric body 104.sub.2 on the detection side is vibrated.
The cycle of the vibration of piezoelectric body 104.sub.2 on the detection side that is generated at that time is the same as the cycle of the vibration in the X-axis direction of the piezoelectric body 104.sub.1 on the driving side, with the amplitude being of such magnitude as is in conformity with the Coriolis force. Since the electromotive force is generated in piezoelectric body 104.sub.2 as a result of the vibration of the piezoelectric body 104.sub.2 on the detection side, the Coriolis force can be detected by measuring its magnitude, thereby obtaining the magnitude of the angular velocity.
With reference to the acceleration sensor, in FIG. 10 the acceleration sensor 202 according to the prior art is composed of base 205 of Pyrex plate glass, an etched silicon mass plate 206 and a cap 207 of Pyrex plate glass having a concave recess in the bottom thereof. Base 205, mass plate 206 and cap 207 are tightly jointed together in this order.
A mass portion 211 having a relatively large thickness and a bridge portion 212 having a relatively thin thickness are provided within a recess of mass plate 206 so that mass portion 211 is movably supported inside acceleration sensor 202.
On the upper surface of mass portion 211 and on the facing bottom surface of the recess in cap 207, electrodes 204.sub.1 and 204.sub.2 made of a thin metal film are formed, respectively, resulting in a variable capacitor of the parallel plate-type formed by electrodes 204.sub.1 and 204.sub.2.
When sensor 202 is subjected to acceleration, mass portion 211 is displaced in conformity with the size of the acceleration in the normal direction of electrodes 204.sub.1 and 204.sub.2, with a result that the distance between the two electrodes 204.sub.1 and 204.sub.2 changes. As a consequence, the capacitance of the capacitor which is formed by electrodes 204.sub.1 and 204.sub.2 changes. If the amount of the change is detected, the magnitude of the acceleration can be measured.
However, the manufacturing steps for the angular velocity sensor and the manufacturing steps for the acceleration sensor as described above are completely different. Such separately manufactured items combined to make a composite sensor, are expensive, more cumbersome and larger in size than is desirable.
In addition, a composite sensor prepared by combining the acceleration sensor and angular velocity sensor as described could not conveniently be arranged on a printed substrate and would be difficult to connect to a measuring circuit. It is therefore desirable to provide a solution to this problem.


A group III nitride compound semiconductor light-emitting device according to the present invention includes: an active layer (105) comprised of a group III nitride compound semiconductor; a current blocking layer (108) which is formed on the active layer (105) and has a striped aperture (108a); a superlattice layer (p-type layer 109) which buries the aperture (108a) and is comprised of a group III nitride compound semiconductor including Al; and a cladding layer (110) which is formed on the superlattice layer and is comprised of a group III nitride compound semiconductor including Al. When an average Al composition ratio of the superlattice layer is represented as x1 and an average Al composition ratio of the cladding layer (110) is represented as x2, it is represented as x1<x2.

A digital versatile disk (referred to as DVD) that is a typical optical disk in recent years is in widespread use in very wide range of fields, from readout systems such as movies, music, games, and car navigation to recording systems such as TV recorders and personal computer mounting drives. Recording capacity thereof is approximately seven times as much as CD, for example, it is sufficient capacity for recording the current TV video in standard image quality. However, when digital hi-vision video to be expected to become widespread in future is directly recorded in high quality, amount of information overwhelmingly increases as compared before; and therefore, the current DVD can only record approximately 20 to 30 minutes. Consequently, a next generation optical disk system which is capable of recording large capacity as much nearly 5 times as conventional DVDs is becoming increasingly expected.
As a light source for use in a next generation optical disk system, a nitride based blue-violet semiconductor laser with a wavelength of 405 nm is used. This is because light can be narrowed down as compared with an AlGaInP based red semiconductor laser with a wavelength of 650 nm used in conventional DVDs and is suitable for high density recording of signals.
An existing nitride based semiconductor laser is not easy for manufacturing due to a material inherent property and it is the common practice to have a ridge structure by dry etching a p-type cladding layer. More specifically, as shown in FIG. 4, an n-type substrate 11, an n-type cladding layer 13, an active layer 15, and a p-type cladding layer 20 which is of a ridge structure are accumulated in this order. Further, the lower surface of the n-type substrate 11 and the upper surface of a ridge portion of the p-type cladding layer 20 are provided with electrodes 22 and 23, respectively. In the case of the nitride based semiconductor laser having the ridge structure, horizontal optical confinement is controlled by refractive-index difference with outside air of the ridge structure. Therefore, the post-etching remaining thickness d of the p-type cladding layer 20 is important parameters for deciding beam shapes.
However, there arise problems as follows. First, since outside the ridge is air with small refractive indexes, a horizontal refractive-index difference Δn comparatively increases. Therefore, it tends to generate a higher transverse mode and it is difficult to perform single transverse mode operation with a high output. The remaining thickness d of the p-type cladding layer 20 needs to be increased in order to reduce Δn in the nitride based semiconductor laser with the ridge structure. In this case, since horizontal current broadening in the p-type cladding layer 20 increases; ineffective current components which do not contribute to laser oscillation are increased to cause increase of operation current.
Furthermore, since outside the ridge structure is air which is low in thermal conductivity, most heat radiation from an emitting region is performed only from the n side. Therefore, the nitride based semiconductor laser having the ridge structure is low in radiation performance and difficult in high output and operation in high temperature.
Further, a ridge waveguide is formed by processing the p-type cladding layer 20 with a method such as dry etching. Therefore, it tends to generate variation in the remaining thickness d of the p-type cladding layer 20 which is extremely important for control of a beam shape; and this is one of factors which make yield low.
In order to solve these problems, there is proposed a nitride based semiconductor laser having an inner stripe structure, disclosed in Patent Document 1, for example. As shown in FIG. 5, in the case of this structure, since outside the stripe is covered with a nitride based material, horizontal refractive-index difference Δn is relatively low. Therefore, single transverse mode operation with a high output can be easily realized.
Furthermore, outside the stripe is covered with a nitride based material having high coefficient of thermal conductivity, and therefore, radiation performance is high and high output and operation in high temperature can be made.
Further, since the portion d corresponding to the remaining thickness in the p-type cladding layer of the ridge structure is formed in crystal growth, variation in layer thickness is small and a beam shape can be stably controlled. Therefore, it is a high yield and superior in mass productivity.
Additionally, since an area in contact with a p-electrode can be widely taken, contact resistance can be reduced as compared with the ridge structure as shown in FIG. 4.
[Patent Document 1] Japanese Laid-open Patent Publication No. 2003-78215

Group III nitride compound semiconductor light-emitting device


In various embodiments of the invention, a server monitors a network for a startup message from a client computer as appropriate. The server may include a computer application that generates configuration instructions in response to commands from an administrator and/or information obtained from a client computer. The instructions may be in the form of scripts, data, objects, or the like. The instructions may be passed to the client computer, which may execute various administrative functions as directed. In exemplary embodiments, the instructions may command direct placement, verification and/or replacement of files, directory entries, BIOS attributes or other characterisitics of the client computer.

As personal computers (PCs) become increasingly prevalent in home and office environments, computer users and administrators are becoming increasingly concerned about the time, effort and expense required to maintain each computer. Indeed, the lifetime cost of maintaining a computer frequently exceeds the cost of purchasing the computer by at least an order of magnitude or more.
With reference to FIG. 1, a typical computer system 100 includes hardware 102 such as a processor, network interface, a keyboard, a mouse, a monitor and the like. Applications 108 suitably communicate with the hardware to perform various functions through operating system 106. If applications 108 include network functionality, a network interface 104 typically receives network calls from the application 108 via operating system 106 and relays them as appropriate to network hardware included with hardware 108. An exemplary network interface includes the network design interface specification (NDIS) available from the Microsoft™ Corporation of Redmond, Wash., although of course other network interfaces could be used in conjunction with various operating systems and hardware configurations.
As can be appreciated, all aspects of computer system 100 are susceptible to failure, error, or the need for upgrade. Operating system components, for example, may be accidentally modified, moved or deleted by a user. Similarly, network drivers or application programs can become corrupted. Accordingly, an ideal administration program would be able to perform administrative tasks, repairs and upgrades on all aspects of the computer system 100. Such functionality typically requires, however, that the administrative tool operates even if the network layer 104, operating system 106 or application layer 108 is not available.
Although various administration tools have existed in the past, these tools have exhibited one or more marked disadvantages. The Intellimirror™ product available from the Microsoft Corporation of Redmond, Wash., for example, operates at the application level 108. Similarly, the Norton Utilities™ and Norton Ghost™ programs available from the Symantec Corporation of Cupertino, Calif. operate at application level 108. Because these programs operate at the application level, their proper execution requires that hardware 102, network layer 104 and operating system 106 be available and functional. If any of these layers 102, 104 or 106 are damaged or otherwise unavailable, the administrative program will not typically function properly.
Conventional administrative programs frequently exhibit further disadvantages in that they typically function on a standalone PC, and as such are not suitable for use in a distributed, networked environment as required by most present day office environments. Distributed administration of networked PCs is desirable because it is frequently cumbersome or inconvenient for support personnel to physically go to the computer to run administrative programs and to execute administrative tasks. Moreover, when an administrator wishes to upgrade or change a particular configuration element on a multitude of PCs, it is often necessary to physically make changes or upgrades on each individual PC. Such a task generally requires a large amount of overhead in terms of time, effort and money.
It is therefore desirable to create a method, system and apparatus to administer, maintain and upgrade computers from a central location. Moreover, it is desirable to maintain and repair these computers even if problems exist with the computer's operating system or network interface.

Method and apparatus for maintaining a computer system


A system for storing video data includes a receiver configured to receive a stream of video data that includes a sequence of original transport packets. Each original transport packet has a first predetermined number of bytes including video data bytes. A first circuit is configured to add a second predetermined number of bytes to each original transport packet to create a modified transport packet having a third predetermined number of bytes. A storage medium is addressable on sector boundaries, wherein each sector has a predetermined number of user data bytes different from the first predetermined number of bytes. The first byte in a modified transport packet aligns with a first user data byte in a sector after a first predetermined number of sectors following a previous alignment.

1. Field of the Invention
The invention relates to a method and apparatus for storing a stream of video data on a storage medium. More particularly, the invention relates to a method of efficiently accessing video data stored on the storage medium.
2. Description of the Related Art
Video systems transmit, process and store large quantities of video data. To create a video presentation, such as a video movie, a rendering video system displays the video data as a plurality of digital images, also referred to as "frames," thereby simulating movement. In order to achieve a video presentation with an acceptable video quality, or to enable transmission and storage at all, a conventional video system modifies the video data prior to transmission or storage. For instance, the video system compresses and encodes the video data to reduce the bit rate for storage and transmission.
In a conventional video system, a video encoder is used to compress and encode the video data, and a video decoder is used to decompress and to decode the video data. The video encoder outputs a stream of video data that has a reduced bit rate and a reduced redundancy. That is, the technique of video compression removes spatial redundancy within a video frame or temporal redundancy between consecutive video frames. The video encoder and video decoder usually operate in accordance with international standards, e.g., a compression process defined by the Moving Picture Expert Group (MPEG), e.g., MPEG-2, or by the International Telecommunications Union (ITU), e.g., the H.263 standard, that define uniform requirements for video coding and decoding. In addition, manufacturers of video coders and decoders modify or build upon the international standards and implement proprietary techniques for video compression.
The video system may store the compressed stream of video data on a storage medium, for example, a hard disk drive (HDD). The HDD may be included in a digital video recorder (DVR) that is coupled to a monitor or a television set in a viewer's home to record and to display program broadcast signals received via a coaxial cable, a satellite dish or an antenna for terrestrial radio frequency (RF) signals. The HDD may have a storage capacity of, for example, between 10 GB and 30 GB to selectively store, and thus record, up to 80 hours of compressed video and audio data. The recorded video data is then available for later reproduction when the viewer decides to watch the recorded video data.
The HDD includes several platters, wherein each platter records information in concentric circles called tracks. Each track is further broken down into smaller units called sectors, each of which may hold 512 bytes of user data. Each sector, however, actually holds more than 512 bytes of user data. Additional bytes are needed for control structures and other information necessary to manage the HDD, locate data and perform other "support functions". For example, the bytes of a sector's synchronization field assist a drive controller to guide the read process. The sectors store the compressed stream of video data that is also broken down into smaller units, which the MPEG-2 standard defines as transport packets. The DVR reads from the HDD in continuous groups of sectors called clusters, wherein the HDD is addressable on sector boundaries.
Despite the existence of the international standards and the availability of sophisticated HDD technology, there is still a need for an improved technique for accessing video data stored on a HDD. In particular, when the DVR accesses the video data to read from the HDD, periods of stream discontinuity may exist during trick play functions such as Fast Forward, Reverse, Rewind and Skip. During these periods, the DVR may lose synchronization.

Method and apparatus for storing a stream of video data on a storage medium


A method of fabricating a SOI substrate is disclosed, which includes the steps of: forming trenches in the Si substrate; forming an oxidation preventing film over the Si substrate and at the side-walls of the trenches; forming grooves at the bottoms of trenches by etching the Si substrate using the oxidation preventing film as a mask; carrying out an oxidation using to form an oxide film and a Si device layer isolated by the oxide film; removing the oxidation preventing film; and carrying out a planarization to form the silicon-on-insulator substrate having a planar surface.

The present invention relates to a silicon-on-insulator ("SOI") substrate and method of fabricating the same, and more particularly to a SOI substrate and method of fabricating the same including a Si device layer having a constant thickness.
In general, in a fabrication process of a complementary metal oxide semiconductor ("CMOS") transistor, an isolation region of a large area should is needed in order to isolate devices and prevent latch-up of a CMOS transistor. There are, however, problems in that an isolation region of a large area results in a reduced chip dimension and a reduced integration of devices.
A SOI technique had been proposed in order to above problems. With complete isolation between devices, a SOI substrate, having a buried oxide film sandwiched between a Si handling substrate and a Si device substrate, prevents latch-up of a CMOS transistor and allows for high operational speed of devices.
One fabrication method of the SOI substrate is a separation by implanted oxygen ("SIMOX") method. In a conventional SIMOX technique, referring to FIG. 1A, there is a Si substrate 1 doped with impurity ions. Oxygen ions are implanted into the substrate 1. Referring to FIG. 1B, an annealing is carried out to form a buried oxide film 2 and a Si device layer 1A in the Si substrate 1. Referring to FIG. 1C, a field oxide 3 is formed in the Si device layer 1A by a LOCOS, thereby forming a SOI substrate 100.
However, the conventional SIMOX technique has a disadvantage in that dislocation in a surface of a Si layer easily occurs when implanting oxygen ions, thereby generating a great quantity of leakage current. Therefore, it is difficult to control a thickness of the Si layer where a device is to be formed.
Another method of fabrication is a bonding technique. In conventional bonding technique, referring to FIG.2A, there are provided a Si device substrate 10 and a handling substrate 11. A buried oxide film 12 is formed on the handling substrate 11 by a thermal oxidation. Referring to FIG. 2B, the handling substrate 11 and the device substrate 10 are bonded, with the buried oxide film 12 existing between substrates 10 and 11. Afterwards, most of the device substrate 10 is etched by grinding and lapping and then the ground and lapped device substrate 10 is chemical and mechanical polished to high degree of precision, thereby forming a Si device layer 10A. Referring to FIG. 2C, an isolation film 13 is formed in the Si device layer 10A to define an active region, thereby forming a SOI substrate 200 having a Si device layer 10A.
According to the conventional bonding technique, it is difficult to precisely control a polishing stop point in chemical and mechanical polishing to form the Si device layer 10A. Since, the thickness of the Si device layer 10A is not constant, yield of semi-conductor devices is reduced. In addition, the conventional bonding technique has disadvantages of a complicated fabrication process and high fabrication cost. Furthermore, the conventional techniques have a shortcoming in that a separate additional process, which forms a field oxide in a Si device layer, is required in order to define an active region.

Method of fabricating silicon-on-insulator substrate

Hyundai Electronics Industries Co., Ltd.


A semiconductor device includes a circuit substrate having a first surface on which a high-frequency circuit is located; a first metal layer disposed on a second surface of the circuit substrate; bump wirings on the first surface of the circuit substrate and electrically connected to the high-frequency circuit; a metal wall disposed on the first surface of the circuit substrate surrounding the high-frequency circuit; a wiring substrate having one surface on which substrate wirings corresponding to the bump wirings are located, the wiring substrate being disposed on the circuit substrate so that the substrate wirings are electrically connected to the bump wirings, and in contact with the metal wall, sealing a region including the high-frequency circuit; and a second metal layer disposed on a second surface of the wiring substrate. An electromagnetic shielding effect sufficient for use in a high-frequency circuit is obtained and fabricating cost is considerably reduced.

FIGS. 9(a) and 9(b) show a prior art semiconductor device in which a semiconductor chip having bump wirings is mounted on a TAB (tape automated bonding) tape or a printed board. In FIGS. 9(a) and 9(b), reference numeral 1 designates a substrate having a first surface where an active layer 4 is disposed. On the active layer 4, source electrodes 5, gate electrodes 6, and a drain electrode 7 are disposed, and these electrodes 5, 6, and 7 and the active layer 4 form a transistor. Reference numeral 2 designates bump wirings comprising Au, which are disposed corresponding to the respective electrodes 5, 6, and 7, and electrically connected to these electrodes. Reference numeral 8 designates a TAB tape or a printed board having a plurality of through-holes 8a. Wirings 9 are electrically connected to the bump wirings 2 through the through-holes 8a.
In the prior art semiconductor device, in order to achieve the maximum performance of the transistor, the wiring structure using the bump wirings 2 as described above is employed in a flip-chip mounting application. More specifically, the heat radiation effect in the transistor is increased by utilizing heat conduction of the bump wirings 2, and the wiring is laid out along the shortest distance from the electrodes of the transistor with the bump wirings 2, thereby reducing wiring delay.
In this structure, however, cavities are produced on the element surface and when the atmosphere of the element surface changes, the wirings are corroded. Further, ion migration occurs because of the difference in quality of the material between the wiring 9 and the bump wiring 2, so that the wirings are degraded. It is impossible to avoid the above-described problem, and this is a serious problem in view of reliability. Even if the chip shown in FIG. 9(b) is completely covered with resin, it is impossible to perfectly hermetically seal the chip, since adhesion or the like of the resin is limited. Consequently, the problem remains to be solved.
In addition, signal noise from the outside is picked up and noise is generated in peripheral circuits. Therefore, especially when an element comprises GaAs and is utilized in a microwave circuit for high frequency, there is a considerable problem.
As described above, in the prior art semiconductor device, corrosion and degradation of the wirings caused by cavities produced on the element surface cannot be avoided, whereby reliability of the device is not improved. In addition, when the element is utilized in a high-frequency circuit, noise is unfavorably picked up or adversely generated in peripheral circuits.
Japanese Published Patent Application No. Hei. 6-236903 discloses a semiconductor device including a metal layer serving as a ground electrode and disposed around an MMIC (monolithic microwave integrated circuit) chip. In this semiconductor device, noise is picked up from the outside through the metal layer, whereby the above-described problem remains to be solved. Further, Japanese Published Patent Application No. Hei. 3-49246 discloses a semiconductor integrated circuit in which a semiconductor chip is mounted on a substrate mounted on a film carrier through bump electrodes. A sealing portion comprising the same material as the bump electrode is provided on the surface of the semiconductor chip where elements are to be formed, along the circumference of the chip, so that the element forming-surface of the chip is hermetically sealed. In this structure, the elements and the wirings are protected from pollutants, such as moisture and impurity ions. Since this reference concerns a silicon device, however, a measure for preventing noise is not provided. Therefore, an electromagnetic shielding effect sufficient for use as a package of a microwave circuit is not obtained.

Sealed semiconductor device including opposed substrates and metal wall


A magnetic head drum of a helical-scan type for video data recording and reading apparatus comprises upper and lower stationary drums securely mounted on a spindle, an intermediate member rotatably supported on the spindle between the drums, and a motor for rotating the intermediate member. The motor comprises a rotor secured to the intermediate member, a stator secured to the upper drum, and a back yoke connected with the rotor through a back yoke retainer such that the stator is interposed between the rotor and the back yoke. This arrangement of the magnetic head drum contributes to effective damping of an electromagnetic noise of the motor caused due to vibration of the stator and back yoke.

The present invention relates to a magnetic head drum of a helical-scan type for magnetically recording and reading video data on a magnetic tape.
Such a magnetic head drum known in the art comprises a stationary spindle, a stationary drum secured to the spindle, a rotary drum rotatably supported on the spindle by bearings, and a motor for rotating the rotary drum. The stationary drum has a cylindrical side wall formed on its outer circumferential face with a helical guide shoulder for helically guiding a magnetic tape thereon. The rotary drum also has a cylindrical side wall which is disposed in circumferentially aligned relationship with the stationary drum and provided at its outer periphery with a magnetic head for recording and reading video signals on the magnetic tape. At an inner circumferential face of the cylindrical side wall of the rotary drum is provided a damping yoke made of a laminated plate including steel films and a resin layer interposed therebetween. The motor comprises a rotor secured to the rotary drum and a stator secured to the spindle being remote at a predetermined distance from the rotor. The stationary drum also is provided with a transformer for the stator which is arranged so as to be opposed to a transformer for the rotor disposed on the rotor side. Further, the stator is provided, at its circumferential edge, with a cylindrical damper in order to restrain vibration of the stator upon rotation of the rotary drum. The vibration causes a noise, viz, electromagnetic noise of the motor.
However, upon rotation of the rotary drum, neither the damping yoke nor the stator with the damper is effectively released from the vibration. As a result, the electromagnetic noise is still generated.
There is a great demand for a magnetic head drum rotatable at high speed without generating the electromagnetic noise and suitable for an apparatus such as a digital video tape recorder.

Magnetic head drum apparatus having upper and lower stationary drums and a rotatable member therebetween arranged to damp noise and vibration


This invention provides an elongated flexible member that is capable of being formed into a plurality of differing shapes so that it can be supported at a variety of locations and has retaining means for retaining it in a desired shape so that a holder connected to one end thereof can hold a flashlight at any desired position relative thereto.

There are many times when a person, who is alone and doing some kind of work, needs a third hand. This is particularly true when a flashlight has to be used so that such a person can see what is being worked on. Flashlights have been laid on any available objects in an effort to provide light at a desired location, but often without good results. Small flashlights have even been held in the mouth of the worker. Thus, there exists a need for a readily portable device that can be used anywhere to hold a flashlight at a desired location to provide needed light.


The present invention pertains to a driven loose wheel axle with individually mounted wheels for single-axle or double-axle chassis for rail-borne vehicles, especially for chassis or bogies on low-platform vehicles, wherein a drive is fastened to the chassis frame on the outside on each longitudinal side of the chassis and the drive is connected to the corresponding loose wheel via a cardanic double coupling. According to the present invention, a wheel-carrying frame (1) with contact surfaces (14) for the primary spring system surrounds the two wheels (2) from the outside; the driven interface (3) of the cardanic double coupling is arranged on the inner side of the wheel and the drive interface of the cardanic double coupling is arranged outside the wheel-carrying frame. The cardan shaft (5) provides a connection between the drive interface and the driven interface (3) and is led through a central opening of the wheel (2) and of the wheel-carrying frame (1).

Nondriven, braked carrying chassis (individual or double-axle carrying chassis), which use so-called loose wheel axles to allow a low floor even in the area of the chassis, have been known from FIGS. 6 and 8 of the article "Neues bei Laufwerkskomponenten und gummigefederten Radern" New Developments in Chassis Components and Rubber-sprung Chassis! published in the journal Der Nahverkehr, No. 6/94. The loose wheel axle comprises essentially a nonrotating axle (portal axle) bent at right angles with bilateral axle heads with axle stubs, on which a usually rubber-sprung loose wheel each is mounted. The chassis frame of the chassis is supported on the loose wheel axle via a primary spring system. For example, the loose wheel axle for the standard gauge has for this purpose two machined contact surfaces for the primary spring system at the axle head on the inner side of the wheel. Even though the loose wheel axles of the above-mentioned designs are equipped with a disk brake, they have no possibility for driving.
Driven loose wheel axles of this type on a double-axle chassis for rail-borne vehicles have been known from DE 44 29 889 A1. A practical embodiment for this is shown, e.g., in the article "Combino, die modulierbare Niederflurstra.beta.enbahn . . . " Combino, the Low-Platform Street Car that Can be Modulated! published in the journal Verkehr und Technik, No. 9/96, pp. 387 ff. A chassis frame is supported here on two loose wheel axles (portal axles) bent at right angles, wherein the primary spring system connecting the contact surfaces for the chassis and axles is located on the inside of the wheels.
The drive to transmit the torque of the loose wheels of the loose wheel axles takes place in the form that a cardanic double coupling, which acts on the outer side of the wheel, is arranged between the primarily sprung, electromechanical drive arranged on the outer side of the vehicle and the corresponding loose wheel.
The design of the loose wheel axles with cardanic double coupling acting on the wheel and connections located on the inside for the primary spring system usually makes it possible, e.g., in the case of standard-gauge vehicles (gauge about 1,435 mm) to arrange a low-platform central aisle between the heads of the loose wheel axle with a sufficient width.
The width of the central aisle of the low-platform car is additionally further limited in an undesired manner due to the arrangement of the contact surfaces for the primary spring system on the inner side of the wheel in the case of vehicles with narrower gauge (e.g., for narrow-gauge railways with a gauge of 1,000 mm), in which the distance between the inner surfaces of the wheels is shorter. This also applies to, e.g., standard-gauge vehicles in which a greater central aisle width is desired than is made possible by the above-mentioned solution.


A backlight assembly includes a light emitting part, a light guide plate and a lower receiving container. The light guide plate includes a side surface and a light exiting surface. The lower receiving container includes a heat sinking part and a rigid part having a strength greater than the heat sinking part.

1. Technical Field
Exemplary embodiments of the present disclosure relate to a backlight assembly and a display apparatus having the backlight assembly. More particularly, embodiments of the present disclosure relate to a backlight assembly having a light source and a display apparatus having the backlight assembly.
2. Description of Related Art
A light emitting diode (LED) may be employed as a light source of a display apparatus such as a liquid crystal display apparatus, an electrophoretic display apparatus, a micro electro mechanical system (MEMS) display apparatus, etc.
In application, the LED generates heat, and the heat generated by the LED may cause damage to components of the display apparatus.
As the number of the LEDs increases in the display apparatus, uniformity of the light generated by the LED increases. Increasing the number of LEDs in the display apparatus may increase the cost for manufacturing the display apparatus.
In an application using LEDs having increased light intensity, the number of the LEDs may be decreased so as to reduce the cost for manufacturing the display apparatus. In such an application, a distance between the LEDs may be increased, and a uniformity of the light generated by the LEDs at a side surface of the light guide plate may be decreased, decreasing a quality of an image displayed by the display apparatus.

Backlight assembly and display apparatus having the same


Incorporates a device for active substances (3) which has a wick (6) and a first heating resistor (8) for operating the diffuser on normal system. It also has a single button (12) connected through an electronic circuit (10) to an additional second heating resistor (9) located in the same channel and after the first heating resistor (8) in the vicinity of the wick (6). Activation of the button (12) determines the switching on of the second heating resistor (9) and can also activate at the same time a fan (4) or even based on a fan speed (4) increase the same, moving from normal operating mode to boost mode in which a substantial and instant increase in evaporation and diffusion of the active substances is produced.

Evaporator devices for active substances comprise in general a container device for the active substance which is diffused by means of a wick and through a casing provided with slots to the outside, the incorporation of a fan being considered as an additional means which contributes to increasing the degree of evaporation promoting the release and propulsion of the active substances.
In the case of patent WO 01/02025, a dispenser fed by a battery which incorporates a device for volatile substances located between the air inlet and outlet of the device, together with a fan which promotes the entry of air inside the device and propels it with the volatile substances to the outside, can be seen. In addition there is a cut-out system which determines the cessation of feed to the fan for a low battery level corresponding to a reduced level of volatile substances contained in the device.
Patent WO 03/086487 relates to an electric evaporator which basically incorporates a device for active substances provided with an external wick, means of heating, a fan and a grid structure through which the active substances pass to the outside. It also incorporates a rotating wheel which controls the position of the wick establishing greater or lesser closeness of the wick to the means of internal heating in order to regulate the degree of evaporation of the active substances.
In this case, the means of regulation linked with greater release of active substances is provided by the manual regulation of said wheel which varies the relative position of the wick with regard to the means of heating. Regulation is slow and the result in being noticed delayed until a period of time has elapsed.
Patent WO 00/69479 describes an evaporator device for volatile substances which includes an electric motor formed by rotor and coil arranged such that when electrical current is applied, the coin generates heat and a magnetic field is produced which causes rotation of the rotor. The volatile material is located adjacent to the rotor in order to be evaporated by the action of the heat of the coil and a fan connected to the rotor propels the active substances to the outside.
In none of the patents cited is there any mention of an evaporator device for active substances which allows any substantial and immediate acceleration of the release of active substances from a constant diffusion system such as the invention described below proposes.

Evaporator device for active substances with fan


An apparatus for cleaning a baseboard of a wall generally comprises an extendable handle to which a friction decreasing device such as a wheel, an adsorbent/desorbent pad and a pad compression device are assembled in a manner such that the lower end of said apparatus can be immersed in a bucket of water.

1. Field of the Invention
The present invention is concerned with apparatus for cleaning baseboards of walls in commercial buildings, residences, institutional buildings and the like. More particularly, this invention relates to baseboard cleaning apparatus whose cleaning pad (e.g., a synthetic sponge) is repeatedly immersed in a bucket of water in order to repeatedly clean said pad during the course of a baseboard cleaning operation.
2. Discussion of the Background
Baseboards of walls are often cleaned by hand. This requires the worker to repeatedly bend, stoop and kneel. These motions are uncomfortable at best, and sometimes even injurious (especially to a worker's lower back region). Consequently, several devices have been proposed to make the task of cleaning baseboards easier. For example, U.S. Patent Publication No. 2006/0182487 A1 discloses a baseboard cleaner having two vertically and horizontally adjustable pads (e.g., a cleaning pad and a drying pad) configured to simultaneously contact a baseboard. This baseboard cleaner further comprises a liquid dispenser, a handle that may be angled rearward and away from the wall, and a roller means such as a set of wheels. U.S. Pat. No. 3,042,952 teaches a baseboard cleaner having a pair of upright plates to which cleaning pads are affixed. A handle is pivotally mounted between the plates. This baseboard cleaner is carried on a pair of rollers. Thus, these two pad baseboard cleaning devices tend to be relatively large, complex, cumbersome and not readily suited to baseboard cleaning operations wherein the cleaning pads are repeatedly immersed in a bucket of water and squeezed in order to clean such pads.


A wiper lever (10) with a wiper arm (12) and a wiper blade (14) linked to it to clean windows of motor vehicles in particular is proposed, whose wiper blade is provided with a band-like, long-stretched-out, elastic supporting element (22) that is curved in the longitudinal direction over its band surfaces (26, 28), which features a rubber elastic wiper strip (30) that can be applied to the window on its concave-curved band surface (26), on whose convex-curved band surface (28) an articulated part (20) sits, on which an adapter (40) is positioned so that it can move in a pendulum fashion, which has walls (42) aligned in the longitudinal direction of the wiper blade and standing on the band surfaces of the supporting element (22) with planes situated at a distance from one another, and locking means (72) are arranged on the adapter that are moveable against a restoring force, which cooperate with counter-locking means (66) of the wiper arm. A particularly operationally reliable connection between the wiper arm and the wiper blade to form the wiper lever is achieved if the locking means are arranged on at least one of the two walls (42) and are moveable essentially transverse to the surfaces of these walls.

The invention relates to a wiper lever. The wiper lever includes a driven wiper arm on which a wiper blade that can be moved over the to-be-wiped window transverse to its longitudinal extension is linked at a distance from this drive end. The articulated axis of the wiper blade essentially extends in its displacement direction. This articulation is of special importance because the to-be-wiped, generally spherically curved window (e.g., the windshield of a motor vehicle) does not represent a section of a spherical surface. As a result, it must be able to continually adapt the wiper blade during its wiper movement to the respective position and progression of the window surface with respect to the movement plane of the wiper arm. An oscillating movement of the wiper blade vis-à-vis the wiper arm around the aforementioned articulated axis is required for this. In a known generic wiper lever (German Laid Open Print DE-OS 10065124), a wiper blade is provided with correspondingly aligned articulated pins via an articulated part that is solidly connected to it, on which an adapter that belongs to the wiper blade is linked, via which the wiper blade can be attached to the wiper arm. Locking means located on the adapter are supposed to provide for an operationally reliable connection between the wiper arm and the wiper blade in cooperation with counter-locking means of the wiper arm. In the case of this adapter that is U-shaped in cross-section, the walls are formed by the two U-legs of the adapter. The adapter is provided with a tongue featuring a locking tooth that is elastically deflectable parallel to the alignment of the walls on its wall forming the U-base that is at a distance from the wiper blade. This tongue extends beyond the end of the wiper arm, whereby the locking tooth acting as the locking means cooperates with counter-locking means of the wiper arm in the sense of a detachable wiper blade safety device.
However, the exposed tongue can also be deflected unintentionally—for example by rotating brushes in car wash facilities—in such a way that the wiper blade detaches from the wiper arm and the vehicle is damaged.

This patent is subject to a terminal disclaimer.

Wiper lever comprising a wiper arm and a wiper blade which is connected to the same in an articulated manner


A system and method for detecting the presence of a moving object within a detection zone is provided. The system includes a first sensor responsive to light in a first range of wavelengths in the detection zone, a second sensor responsive to light in a second range of wavelengths in the detection zone, wherein the second range of wavelengths is different from the first range of wavelengths, and a processing component for generating a variable threshold value for the first sensor based upon at least maximum and minimum output signals from the second sensor within a predetermined period of time, and for comparing the first output signal with the variable threshold value. The processing component generates an activating signal if the first output signal exceeds the threshold value.

1. Field of the Invention
The present invention generally relates to sensors and security system. More particularly, this invention relates to a motions detection system and method for detecting the presence of an intruder by utilizing passive infrared (PIR) motion sensors, which is capable of reducing false alarm due to white light in the security system.
2. Related Art
PIR motion sensors are popularly used as automatic light switches, alarm sensors or to control other electrical appliances. For example, the sensors detect the infrared light emanating from an intruder, such as a human or motor vehicle, and transmit a signal to activate an alarm. The PIR sensors, which are designed to be sensitive to the IR energy produced by the human body temperature range, include a light filter that passes energy between 7 micrometers and 14 micrometers while blocking the remainder. Thus, light in the visible spectrum is either reflected or absorbed by the filter. The energy that is absorbed by the filter causes heating of the filter. This heat is reradiated and is detected by the pyroelectric sensing elements of the sensors.
It is possible therefore for visible light to be converted into IR energy, thereby causing the sensors to issue a false alarm. Thus, PIR motion sensors are inherently susceptible to detecting stimuli not associated with the intruders. Specifically, passive PIR motion sensors are susceptible to the energy produced by automobile headlights and other light resources emanating from outside the region being monitored by the sensors. The energy produced by automobile headlights within a certain distance from the sensors can be sufficient to cause a false alarm issued from the sensors. False alarms in a security system having intrusion detection sensors are a significant distraction to the police force and can be very costly in fines to the owners of the security system.
Traditional approaches to solving this issue include augmenting the out of band energy blocking ability of the pyroelectric detector window/filter with either: 1) adding pigmentation to the lens intended to block "white light" while passing infrared energy (for example, Zinc Sulfide) or 2) the addition of a secondary optical filter. Both approaches have their drawbacks and neither approach satisfies the desire for significantly improved, if not unlimited white light immunity.
U.S. Pat. No. 7,161,152 to DiPoala describes a method and system that provides the potential for unlimited white light immunity, in which a secondary light sensor is utilized to detect when lighting conditions on the motion detector change. If the change in light intensity exceeds a predetermined threshold for this light sensor, the DiPoala system prohibits any potential alarm signal from being generated within a predetermined time period of this change. More specifically, in order to generate an alarm signal, the PIR sensor signal shall exceed a first predetermined threshold for the PIR sensor and, simultaneously, the visible light sensor signal shall not exceed a second predetermined threshold for the light sensor. In other words, the system suppresses sending out an alarm signal if the intensity of the visible light exceeds a predetermined threshold.
Due to foregoing reasons, the DiPoala system does present a potential problem that it is possible for an intelligent intruder to "blind" the motion detector by briefly sweeping a flashlight across the motion detector to shine light upon the detector while he traverses the protected area, thereby suppressing the generating of an alarm signal.
Therefore, it would be very advantageous to provide a motion detecting method and system that provides significantly improved, if not unlimited white light immunity as well as obviates intentional blinding of the sensor by an intruder.


A recording medium according to the invention has a magnetic recording layer with an L10 magnetic material deposited with a (111) preferred orientation and soft underlayer (SUL). One set of embodiments includes an intermediate layer (seed layer or underlayer) between the L10 media and SUL. The intermediate layer can be a close-packed surface structure (triangular lattice) to promote (111) orientation of the L10 media. For example, the intermediate layer can be a (111) oriented, face-centered-cubic (fcc) material such as platinum, palladium, iridium, rhodium, FePt, FePd, or FePdPt alloys; or the intermediate layer can be a (100) oriented hexagonal-close-packed (hcp) material such as ruthenium, rhenium, or osmium. Alternatively, the intermediate layer can be an amorphous material. The L10 recording layer of the invention can be deposited with a matrix material to form grain boundaries and provide magnetic isolation of the grains of L10 material.

A typical prior art disk drive system 10 using perpendicular recording is illustrated in FIG. 1. In operation the magnetic transducer (head) 14 is supported by the suspension (not shown) as it flies above the rotating disk 16. The magnetic transducer 14, usually called a "head" or "slider," is composed of elements that perform the task of reading and writing magnetic transitions. In a disk drive using perpendicular recording the recording head is designed to direct magnetic flux through the recording layer in a direction which is perpendicular to the plane of the disk. Typically the disk 16 for perpendicular recording has thin films 21 including a hard magnetic recording layer 28 and a magnetically soft underlayer 29. During recording operations using a single-pole type head, magnetic flux is directed from the main pole of the recording head perpendicularly through the hard magnetic recording layer, then into the plane of the soft underlayer and back to the return pole in the recording head. The shape and size of the main pole and any shields are the primary factors in determining the track width. The write head portion (not shown) of head 14 uses pole piece 42.
U.S. Pat. No. 6,531,202 to Litvinov, et al. is an example of a magnetic recording medium for perpendicular or vertical recording. The medium includes a magnetically soft underlayer deposited on the substrate. Suitable soft magnetic materials are said to include CoFe and alloys thereof, FeAIN, NiFe, CoZrNb and FeTaN, with CoFe and FeAIN being preferred soft materials. A magnetically hard recording layer is deposited on the soft underlayer. Suitable hard magnetic materials for the recording layer are said to include multilayers of Co/Pd or Co/Pt, L10 phases of CoPt, FePt, CoPd and FePd and hcp Co alloys, with such multilayers and L10 phases being preferred hard materials.
In U.S. Pat. No. 6,524,730 to Ga-Lane Chen a soft magnetic underlayer for vertical recording is referred as "keeper layer". The soft underlayer is said to give better writing efficiency by pulling the magnetic flux down from the writing pole of a head of the magnetic recording medium. Examples given of soft magnetic materials are NiFe, CoZrNb, FeAINx.
Bulk tetragonal L10 ordered phase materials (also called CuAu (I) materials), such as CoPt and FePt, are known for their high magnetocrystalline anisotropy and magnetic moment, properties that are also desirable for high-density magnetic recording media. The C-axis of the L10 phase is similar to the C-axis of hcp CoPt alloys in that both are the easy axis of magnetization. Thus, while the disordered face-centered-cubic (fcc) solid solution of Co and Pt has cubic symmetry and low magnetic anisotropy, the ordered L10 phase has uniaxial anisotropy similar to, but greater in magnitude than, hcp CoPt alloys. U.S. Pat. No. 6,007,623 to Thiele, et al., describes a method for producing a horizontal magnetic recording medium that has as its magnetic film a granular film with grains of a chemically-ordered FePt or FePtX (or CoPt or CoPtX) alloy in the tetragonal L10 structure. These granular films reveal a very high magnetocrystalline anisotropy within the individual grains. The film is produced by sputtering from a single alloy target or co-sputtering from several targets. The granular structure and the chemical ordering are controlled by means of sputter parameters, e.g., temperature and deposition rate, and by the use of an etched seed layer that provides a structure for the subsequently sputter-deposited granular magnetic film. The structure of the seed layer is obtained by sputter etching, plasma etching, ion irradiation, or laser irradiation. The magnetic properties, i.e., Hc and areal moment density Mrt, are controlled by the granularity (grain size and grain distribution), the degree of chemical ordering, and the addition of one or more nonmagnetic materials, such as Cr, Ag, Cu, Ta, or B. These nonmagnetic materials are partly incorporated into the grains, but mainly accumulate at the grain boundaries. The role of the nonmagnetic material is thus to "dilute" the magnetization and to decouple the magnetic exchange between the grains.
The use of SiO2 with CoPtCr to enhance grain boundary formation without disrupting the epitaxy in perpendicular magnetic recording media has been described. (T. Oikawa, et al., "Microstructure and Magnetic Recording Properties of CoPtCr—SiO2 Perpendicular Recording Media", IEEE Transactions on Magnetics, vol. 38, no. Sep. 5, 2002, pp. 1976-1978.)
Tilted magnetic recording is one of the leading candidate technologies for extending hard disk drive (HDD) areal density to beyond one Tb/in2 and data rates beyond one Gb/s. What is needed is a manufacturable way to make high SNR media with an anisotropy direction approximately 45 degrees out of the plane of the disk surface. The head structure and basic media fabrication methods for perpendicular recording can be used with tilted media. Tilted recording devices can be expected to cost about the same as currently available technologies. Tilted recording has a number of benefits over perpendicular recording. First, the anisotropy field and magnetization of the medium can both be approximately doubled (to around Hk 30 kOe and Ms=800 emu/cc) since the grains are easier to reverse for a given maximum head field. The fourfold increase in energy density means a fourfold reduction in grain volume without thermal stability problems. Second, switching field variations due to the distribution in anisotropy angle are up to 10 times smaller for tilted recording. This results in much sharper bit transitions and higher bit density. Third, the guard band between tracks is much smaller for tilted recording because the switching field and energy barrier increase for the larger write field angles at the track edge. Fourth, tilted recording is capable of much higher data rates than perpendicular recording since the reversal torque is much higher. Switching times up to ten times shorter than for perpendicular recording have been reported.
Gao and Bertram have proposed using a soft underlayer with a magnetic layer with 45 degree anisotropy tilted out of the plane of the disk in conjunction with single pole heads. The anisotropy orientation can be cross-track, down-track or randomly distributed. In their theoretical paper, Gao and Bertram do not give materials or techniques for producing the hypothetical media which they analyze. (Kai-Zhong Gao and H. Neal Bertram, "Magnetic Recording Configuration for Densities Beyond 1 Tb/in2 and Data Rates Beyond 1 Gb/s", IEEE Transactions on Magnetics, vol. 38, no. 6, November 2002, pp. 3675-3683.)
The use of MgO(111) underlayer to improve the crystallographic orientation of L10 FePt(111) films has been discussed by Jae-Yoon Jeong, et al. The FePt was deposited at a temperature of 300° C. and then annealed 400°-500° C. for one hour. (Jae-Yoon Jeong, et al., "Controlling the Crystallographic Orientation in Ultrathin L10FePt (111) Films on MgO(111) Underlayer," IEEE Transactions on Magnetics, vol. 37, no. 4, July 2001, pp. 1268-1270.

Magnetic recording media for tilted recording

Hitachi Global Storage Technologies Netherlands B.V.


A steering system on a marine vessel includes a steering wheel, a wheel sensor configured to measure wheel movement of the steering wheel, a steering actuator configured to rotate a steerable component based on movement of the steering wheel, and a variable resistance device controllable to apply a variable resistance amount to resist movement of the steering wheel. The system further comprises a controller that controls the variable resistance device and is configured to receive the wheel movement measurements by the wheel sensor and determine a resistance amount based on the wheel movement measurements and a corresponding steering response relative to the response capability of the steering system, and then to control the variable resistance device based on the resistance amount.

U.S. Pat. No. 6,273,771, incorporated by reference herein in its entirety, discloses a control system for a marine vessel that incorporates a marine propulsion system that can be attached to a marine vessel and connected in signal communication with a serial communication bus and a controller. A plurality of input devices and output devices are also connected in signal communication with the communication bus and a bus access manager, such as a CAN Kingdom network, is connected in signal communication with the controller to regulate the incorporation of additional devices to the plurality of devices in signal communication with the bus whereby the controller is connected in signal communication with each of the plurality of devices on the communication bus. The input and output devices can each transmit messages to the serial communication bus for receipt by other devices.
U.S. Pat. No. 7,727,036, incorporated by reference herein in its entirety, discloses a system and method for controlling movement of a marine vessel. An operator controllable device outputs a signal that is representative of an operator-desired rate of position change of the vessel about or along an axis. A sensor outputs a signal that is representative of a sensed actual rate of position change of the vessel about or along the axis. A rate of position change controller outputs a rate of position change command based upon the difference between the desired rate of position change and the sensed rate of position change. A vessel coordination controller controls movement of the vessel based upon the rate of position change command.
U.S. Pat. No. 7,941,253, incorporated by reference herein in its entirety, discloses a marine propulsion drive-by-wire control system that controls multiple marine engines, each one having one or more PCMs, i.e. propulsion controller, for controlling engine functions which may include steering or vessel vectoring. A helm has multiple ECUs, electronic control units, for controlling the multiple marine engines. A CAN, controller area network, bus connects the ECUs and PCMs with multiple PCM and ECU buses. The ECU buses are connected through respective isolation circuits isolating the respective ECU bus from spurious signals in another ECU bus.
U.S. Pat. No. 9,908,606, incorporated by reference herein in its entirety, discloses a drive-by-wire control system for steering a propulsion device on a marine vessel that includes a steering wheel that is manually rotatable and a steering actuator that causes the propulsion device to steer based upon rotation of the steering wheel. The system further includes a resistance device that applies a resistance force against rotation of the steering wheel, and a controller that controls the resistance device to vary the resistance force based on at least one sensed condition of the system.
U.S. Pat. No. 10,196,122, incorporated by reference herein in its entirety, discloses a steering system on a marine vessel including a steering wheel movable by a vessel operator to steer the marine vessel and a variable resistance device controllable to apply a variable resistance amount to resist movement of the steering wheel. The system includes a control unit that controls the variable resistance device to determine a baseline resistance amount based on vessel speed and/or engine RPM and detect at least a threshold change in angular position of the marine vessel. The control unit then controls the variable resistance device to prevent a decrease in the resistance amount below the baseline resistance amount or to increase the resistance amount above the baseline resistance amount.

Marine steering system and method providing resistance control