A vehicle seat with a rigid seat base, and at least one foam portion disposed on the seat base. The seat defines at least one cavity therein. The cavity is accessible from the bottom surface of the seat, and accepts cargo, such as a shovel, therein. The cavity may be shaped to conform to a specific, predetermined cargo. The seat may be molded by disposing the seat base in a mold, and introducing settable foam into the mold so as to fill the portion of the mold not occupied by the seat base. The foam portion so produced conforms to the shape of the mold, such that a cavity may be formed by providing the mold with an internal projection. The seat may be removably attached to a vehicle using a quick-release mechanism, such as a pin and spring catch.

1. Field of the Invention
The invention relates to a vehicle seat with a layer of foam, having a cavity for storage, to a method of producing a vehicle seat with a layer of foam, and to a method for attaching a vehicle seat to a vehicle.
2. Description of Related Art
Seats for accommodating people on a vehicle such as a snowmobile are well-known. Vehicle seating systems commonly include a generally rigid base, with one or more foam portions or similar material to provide padding.
It is also known to make provision for carrying cargo on vehicles.
Several arrangements for carrying cargo on a vehicle are known. However, conventional arrangements have disadvantages.
Cargo can be attached to the exterior of a vehicle, for example with straps, pins, or similar fixtures. However, cargo attached to a vehicle's exterior is exposed to the outside environment, and any hazards posed thereby, i.e. dirt, mud, snow, impacts from debris or obstacles, etc. In addition, cargo attached to a vehicle's exterior is prone to falling off, sometimes without the vehicle operator even being aware of the loss.
In some instances, vehicles may be made with external recesses suitable for attaching cargo therein. However, although this provides limited protection, the cargo nevertheless is exposed to the outside environment.
Cargo also can be stored in enclosed compartments disposed on or inside of the vehicle. However, cargo compartments within the vehicle conventionally take up space that otherwise would be devoted to some other purpose, i.e. space for the rider, the engine, etc. Either the available internal volume of the vehicle is reduced, or the vehicle must be made larger to compensate for the additional volume required. Enclosed cargo compartments affixed to the outside of a vehicle increase the exterior size of the vehicle, which may make it more difficult to maneuver the vehicle when space is limited, and near obstacles. This is of particular concern for vehicles, such as snowmobiles, that travel off-road, where obstacles are especially common. In addition, whatever their location, conventional enclosed compartments increase the overall weight of the vehicle.
Conventionally, seats with a foam portion are produced as several separate components, which are then fixed together. For example, a seat base is produced, a foam portion is produced, and the two are then fitted together and connected with adhesive, screws, etc.
However, this is disadvantageous, particularly but not only for forming a seat having a cavity therein for cargo. When joining one or more foam components to a seat base, it is necessary to manufacture each part separately. Each foam component must be cast, cut, or otherwise pre-formed to the proper shape, fitted to the seat base, and then attached thereto. This requires a significant amount of time and effort. These disadvantages are especially pronounced when the foam portion has a complex shape, i.e. one with a cavity therein for cargo.
In addition, conventional vehicle seats are mounted on vehicles in a permanent or semi-permanent fashion. For example, the seats may be connected with a large number of bolts, screws, etc., which require considerable time and effort to remove, if they are removable at all.
Access to areas directly under the seat therefore can be inconvenient with conventional designs. If it becomes necessary to access some structure under the seat, a significant amount of disassembly may be required. This is a disadvantage, especially on small vehicles wherein the seat covers a relatively large portion of the vehicle's surface. It is in particular a disadvantage for vehicles having a cavity for cargo storage therein, since for some embodiments the cavity may be located on an undersurface of the seat. In such an instance, a long and/or complicated seat removal process may make it difficult to access the cargo when it is needed.
In addition, for certain embodiments it may be disadvantageous to leave a seat permanently attached to a vehicle. For example, certain types of foam conventionally used in vehicle seats are prone to absorbing moisture. Seats often are more readily dried if they are removed from the vehicle. Likewise, it may be desirable in certain embodiments to remove a seat for storage of the vehicle, or as a security measure to dissuade theft. However, if the seat is permanently or semi-permanently attached to the vehicle, removal for such purposes may be difficult.


A feeding apparatus includes an upper movable carrier (1) having a plurality of guides or receptacles (7) which are transported at a predetermined speed and with a predetermined spacing along a predetermined path. The guides each have an open bottom and are each adapted to receive articles which are individually fed thereto. Over a first portion of its path, each guide (7) lies immediately above a lower carrier (11) which closes the bottom of and moves in synchronism with the guide (7), so as to allow one of the articles to become held within the guide (7) by the lower carrier (11) for a sufficient period of time as to allow the article to settle. Over a subsequent portion of the path, the guide (7) and the lower carrier (11) are separated from one another, thereby exposing the article on the lower carrier with accurately defined position and timing.

It is a common practise to sort individual articles sequentially, for example according to their individual weight, colour, clarity etc. This is done for example in the case of diamonds and other stones, sweets, peas, tablets and other medical preparations, and many other articles. When the relevant quality has been measured or detected by appropriate sensing means, the articles must be correspondingly sorted. The sorting may comprise only two categories namely "pass" and "fail", but in many cases it is desirable to sort into a plurality of categories, for example ranges of weight or colour. For accurate sorting, the sorting means must be synchronized with the sensing means, and the articles must be presented to the sorting means with accurate placing and timing to avoid incorrect sorting. The articles may well leave the sensing means with some irregularity in speed, direction, position or timing, and such irregularities need to be reduced or eliminated before the articles are presented to the sorting means.
Ensuring that a sequence of articles is presented with accurately defined timing and placing is also desirable in other contexts, for example in presenting the articles to a sensing means for determining the weight, colour or some other quality.

Method and apparatus for feeding articles


A scale assembly for weighing potentially hazardous materials comprise a containment deck designed to support a container from which materials are dispensed. The containment deck is preferably provided with sufficient storage capacity to capture spillage or leaks from the container and is supported on a low-profile platform supported in turn by load cells which generate signals indicative of the weight of the contents of the container and of any spillage within the containment deck. The containment deck is further equipped with a level detector typically positioned near the bottom of the deck for generating signals indicating the presence of leakage or spillage from the container.

In the handling of such materials, particularly in the unloading and loading of containers of the materials and for dispensing from them, it is a generally followed practice, increasingly required by law, to support the full containers, such as tanks, drums, intermediate bulk containers or tote bins, on spill containment decks which may be raised above the floor or other support surface. Such containment decks are provided with a sump designed to contain spillage from the containers as may occur when the container is being filled or when its contents are withdrawn. The decks are generally constructed of an inert material which is non-reactive with materials being dispensed, and generally have a reservoir which is large enough to accommodate spillage or leaks, thereby preventing the container contents from contaminating ground water or reacting with the concrete or other floor materials or from coming into contact with the shoes or clothing of the workers dispensing or filling the containers or transporting the materials as may be required.
It is highly desirable to accurately keep track of amounts of materials dispensed from or added to containers, and for this purpose, it is desirable that the container be supported on a scale for the purpose of monitoring amounts withdrawn and the amount remaining in the container at any given time. Inclusion of the amount of spillage in the amount weighed is considered to be important and to be taken into account in evaluating usage and the efficiency of various treatment process for which the materials are intended to be used. It is also particularly important to separately measure the spilled amount so that the risk of any harm can be accessed.
A need exists for a low-profile weighing apparatus for support of a containment deck. Such apparatus must be of minimal height, as the containers can be quite heavy and difficult to manage when placed on the surface of a conventional containment deck. If the support surface of the containment deck is too high, conditions of instability may be created and contribute to accidents resulting in spillage. The containers may be heavy and difficult to load and unload from the deck under the best of circumstances. Providing a support system and weighing apparatus with a low overall profile is critical to avoiding accidents to workers and to the environment.
To date, there has been no known containment deck scale that fills these requirements.


In order to provide a timing mark at a specific place on part of a timing chain in a manner in which the quality of the timing chain is maintained, a timing chain 4, made endless by outer plates 1 and inner plates 2 being connected by means of connecting pins 3 is provided with a timing mark 1' at a specific part on one side of an outer plate 1. The timing mark 1' is placed on the outer plate 1 between the connecting pins 3 and is in the shape of a web extending from an inner edge of the outer plate 1 to an outer edge thereof. The timing mark 1' is provided by baking a coating on the outer plate 1 after the timing chain has been assembled.

The present invention relates to a timing chain wound between members which require a synchronous rotation. The timing chain of the present invention is wound, for example, between a crank sprocket and a cam sprocket of an engine for a vehicle, and is used for the synchronous rotation of a crank shaft with a cam shaft. Alternatively, the timing chain of the present invention can be wound between a crank sprocket and a balancer sprocket of an engine for a vehicle, and used for the synchronous rotation of a crank shaft with a balancer shaft.
A timing chain used for the synchronous rotation as mentioned above typically employs a sprocket having timing marks and a timing chain having timing marks. The timing marks are made to register when the timing chain is wound about the sprocket for achieving the synchronous rotation.
Incidentally, generally, the timing marks of the timing chain are provided by a method in which some marks are imposed on a single plate prior to construction of the timing chain. There is a further method of applying some marks to the timing chain by a plating treatment to provide timing marks. In this method, however, because gases generated during the plating treatment, for example, hydrogen, should be removed, and addition of a baking treatment is necessary to prevent the lowering of fatigue strength, the process management should naturally be severe, and the production efficiency is extremely bad.
The applicant has previously proposed a timing chain applied with timing marks by a color baking coating as disclosed in Japanese Patent Laid-Open No. 242829/1997. In this timing chain, timing marks obtained by the color baking coating are applied to outer plates of a part composing the timing chain, which is composed endlessly together with other plates.
However, according to these prior art practices the outer plates having timing marks are prepared via a manufacturing process separately from other outer plates. Therefore, it is necessary to store, as stock, outer plates having timing marks and outer plates having no timing marks for every type of timing chain. This poses a problem in that many steps for managing parts constituting the timing chain are necessary, and the securing of storage areas for the respective parts is very wasteful.
Further, since coated outer plates are assembled with other plates, the coated outer plates have to be incorporated into the specific parts in the midst of construction of the timing chain. Normally, the specific parts are positioned on one side of the timing chain though different according to the type of the timing chain, and are positioned at two places in the chain. Accordingly, when the timing chain is constructed, it is necessary to specify the surface and back of the timing chain, as well as to specify the predetermined position in the chain, and then to assemble the coated outer plates. Further, since the coated outer plates have to be switched to the other outer plates to compose the timing chain, a number of steps are required to assemble the timing chain.
Furthermore, since, after the entire surfaces of the respective outer plates have been coated, during construction of the timing chain, when the outer plates are pressed into the pins upon assembly of the timing chain, the coating is sometimes peeled off. When the coating is partly peeled off, the external appearance of the timing chain becomes worsened. When the coating is completely peeled off, the timing marks cannot be discriminated, and failure to assemble them between the members, for which the synchronous rotation is required, occurs.

Timing chain with timing marks and method of manufacturing the same


A built-in self-test, BIST, radar unit (100) is described. The BIST radar unit (100) comprises: a frequency generation circuit (110) configured to generate a mmW transmit signal; a transmitter circuit comprising: at least one phase shifter (130, 132) configured apply at least one phase shift to the mmW transmit signal; and at least one phase inverter (140, 142) coupled to the at least one phase shifter (130, 132) and configured to invert a phase of the phase shifted mmW transmit signal. A receiver configured to receive and process a received version of the mmW transmit signal. The at least one phase inverter (140, 142) is configured to rotate the phase shifted mmW transmit signal to apply a secondary modulation to the mmW transmit signal; and the receiver is configured to receive and process a received version of the mmW transmit signal to determine an operational state of the BIST radar unit (100) based on a determined phase shift performance of the secondary modulation of the received version of the mmW transmit signal.

A majority of the current millimetre wave (mmW) radar units are constructed using mmW integrated circuits (ICs) that include multi-channel transceivers (TRX) that are operable across a number of frequency channels. The mmW ICs also include high frequency devices, such as, power amplifiers, mixers, low noise amplifiers (LNAs). In the automotive radar field, the supported frequencies are in the 27 GHz and 76-81 GHz frequency bands.
Modern automotive radar systems use multiple transmitters and receivers to enable angle detection of the detected objects. Having a multi-channel transceiver, with associated mmW phase shifters, enables multiple in-multiple out (MIMO) techniques to be used to enhance the angular resolution. This allows applications, such as cruise control (that relies on restricting the radar beam to the lane the car is currently cruising), or such as blind angle detection (that relies on restricting the radar beam to this blind angle). In addition to the multiple channels, coding of the transmitter signals is needed to be able to distinguish between the transmitted signals. A MIMO radar with m transmitters and n receivers has m×n channels. The higher the number of channels, the higher the angular resolution of an identified received signal can be achieved.
Automotive safety standards such as ISO 26262 mandate the use of mitigating measures in case of safety-relevant defects; these mitigating measures need to be completed within a defined time interval that is small enough to prevent a system failure that could be dangerous to a person inside or outside the vehicle. Detecting safety-relevant defects in the radio frequency (RF) front-end of a car radar system can be performed using plausibility checks done in the radar unit that evaluates the RF front-end's output signal and calculates the target map from this signal. If this target map shows, e.g., suddenly appearing or disappearing targets, this would then lead to the target map being classified as not plausible and the RF front-end as possibly defect so that the unit could initiate safety measures, e.g. system reset, repetition of the measurement cycle, or notifying the driver that the radar system needs to be considered unsafe.
While such plausibility checks are very common in safety-critical systems, they have two severe drawbacks. A first drawback is directly related to safety, as every plausibility check bears the risk of false-positive or false-negative decisions. A second drawback is that such plausibility checks need to be implemented, documented and verified for a large number of possible faults including transient faults. All of these procedures are time-consuming and error-prone. These two drawbacks make it desirable to avoid the need for plausibility checks and to implement as much built-in safety monitoring as reasonable in the safety-critical elements themselves. As transient faults are a major source of malfunctions, it is desirable to be able to test these.
In vehicle radar systems, functional safety is crucial, as a malfunction can either lead to a dangerous situation—e.g. automatic braking because the malfunctioning system reports targets which actually don't exist, or to a failure to react, e.g. if existing targets are not detected. For both cases, a moderate system performance degradation is often the worst-case scenario, as a complete system failure would be immediately detected, whereas a moderate performance degradation might only lead to misinterpreting a target's size, position, direction of movement, etc., which could cause one of the above-mentioned malfunctions. This is especially true for malfunction of phase shifters in multi-transmitter vehicle radar systems, as such malfunction might lead the radar beam to be directed to a different angle than intended.
The measurement of phase at mmW frequency is very challenging and requires expensive test equipment. The phase shifter accuracy is measured in the laboratory using expensive mm-wave test setups, performed on a few samples. The measurement of the phase in a standard automated testing equipment (ATE) environment is not possible as standard ATE analog cards have an upper frequency limit in the approx. 100 MHz-range. Also, the direct measurement of the phase would requires down-converting the 77 GHz signal, which is usually not available in an ATE.
On-line self-test for functional safety is supported in some test systems, enabling concurrent tests to be performed in an application (normal operational) mode and, thus, also enabling detection of some transient failures due to single event upsets. It is known that an inaccurate phase may lead to an inability to distinguish the different signals coming from different transmitters. In this case the effective number of channels is reduced, which consequently reduces the angular accuracy.
Thus, there exists a need for an improved mechanism to measure a phase shift of radar unit with a mmW on-chip, for example using an on-chip internal RF built-in self-testing (BIST) system.

Built-in self-test radar unit and method for phase shift measurement therein


An image detector includes a surface sensitive to photon radiation which is protected from the external environment by a transport window with an internal diopter and an external diopter which is integral with a housing and is placed in front of the sensitive surface. In order to eliminate the phenomenum known as "blooming" due to parasitic reflections causes by intense radiation, the window is formed by a transparent, nondiffusing medium which attenuates photon radiation, with the internal diopter of the window being at a distance from the sensitive surface which is smaller than or at most equal to several times the resolution distance of the detector. Additionally, the external diopter is sufficiently far removed from the sensitive surface such that the first reflection of the radiation coming from a source of maximum radiation will have a level, on the sensitive surface, which is lower than that of the direct radiation coming from a source of minimum radiation which is to be detected.

The invention relates to an image detector comprising a surface sensitive to photon radiation and protected from the external environment by a transparent window which is integral with a housing and is placed, with an internal diopter and an external diopter, in front of the said sensitive surface, the latter having a surface quality capable of generating radiation reflections over angles which can amount to several dozens of degrees relative to the direction of mirrored reflection on the said surface.
The invention relates particularly to earth sensors and more particularly to earth sensors having a matrix of photosensitive elements with charge transport (CCD matrix) for geostationary satellites.
Image detectors may be classified into two families: those having vacuum tubes whose sensitive surface exposed to photon radiation is a photocathode and those having semiconductor units organized into strips or into a matrix of image elements (or pixels). In most cases, the photosensitive surface of these detectors requires protection against pollution or against degradation caused by the external environment surrounding the detector, whether this relates to dust in the earth's atmosphere or the components of this atmosphere themselves. This protection consists of a window (or porthole) arranged in an impermeable manner in front of the sensitive surface and transparent to the photon radiation to which the relevant detector is sensitive. The window is formed by a glass of optical quality having an internal diopter and an external diopter. The contrast of the image to be analyzed may be impaired in the presence of a source of strong brightness in the field of vision owing to multiple reflections generated, starting from the sensitive surface itself, by secondary parasitic reflections on the two diopters of the protective window. When points or spots of very strong luminance against a weakly illuminated background are observed, these parasitic reflections generate halos on the photosensitive surface whose levels may be much higher than that of the observed scene on earth, or, in space, than any other light source of lesser strength which one wants to observe and which thus constitutes the useful signal, but which is then drowned in the noise. A typical case in which this technical problem arises is when the image detector is a sensor of the earth's contour on board a geostationary satellite and is formed by a CCD matrix for a radiation range comprising the entire visible radiation and the adjoining infrared. However, the earth must be permanently monitored by the detector for a nominal operation of the latter, while the orbit of the satellite is such that during several months of the year, around each equinox, the sun is in the field of the detector for several hours around midnight local time during each revolution of 24 hours. In this illumination situation the luminescence of the sun is approximately 10.sup.6 to 10.sup.7 times stronger than that of the earth's contour. When no special measures are taken, the image of the luminous signal coming from the sun and deflected by the atmosphere around the earth would disappear in the matrix in the parasitic light coming directly from the sun and reflected first by the matrix itself and then by the two diopters of the protective window.
The matrix CCD TH 7864 from Thompson-CSF could form a good image detector suitable for the exact application cited as the last one above, provided it were possible to dispense with the protective window which closes the housing. It is not possible, however, to do away with this window which has a mainly protective function, while an inert gas such as nitrogen, for example, fills the volume confined between the window and the matrix. The known TH 7864 matrix referred to above comprises a housing to the bottom of which the silicon slice forming the actual detector is glued, which housing is provided with rims surrounding the slice and defining a surface which lies in a plane situated at a distance of 0.84 mm above the sensitive surface of the detector. A window of optical glass of 0.9 mm thickness is glued against this surface, perfectly transparent to visible light. In these conditions, the two parasitic halos generated around the image of the sun on the matrix by the direct reflection of the sunlight on the matrix and subsequently on the two diopters occupy diameters of the order of 100 pixels and 200 pixels, respectively. Supposing that the detector is to cover a field greater than the apparent diameter of the earth, and that the diameter of the sun is of the order of 35 times smaller than that of the earth viewed from a geostionary orbit, the direct image of the sun has a typical diameter of 6 pixels and that of the earth of 200 pixels. Since the detection of the earth must be assured even when the sun is close to it or on its edge, the image of the earth which one wants to measure is to a major extent or completely masked by each of the two parasitic halos.
Devices for reducing blooming effects in image detectors are known. A first measure to achieve this object is to provide the objective which is placed in front of the detector with photochromic lenses. When the detector is a vacuum tube, another solution is to interpose a strip of microchannels in the electron path. When the photocathode of the tube receives a strong, point-shaped illumination, the local saturation properties of the strip of microchannels limit the blooming while still rendering possible the observation of the remaining landscape .

Image detector with reduced parasitic light


A circuit includes an OPAMP-less bandgap voltage generating core circuit connected between a regulated voltage and a ground reference to generate an output bandgap voltage. A preregulator circuit generates the regulated voltage from an unregulated supply voltage. The preregulator circuit includes a negative feedback loop operable to stabilize the regulated voltage and a current source operable to source current for the regulated voltage, the current source mirroring a PTAT current of the OPAMP-less bandgap voltage generating core circuit. The core circuit further includes a negative feedback loop and a positive feedback loop, the negative and positive feedback loops functioning to equalize two internal voltages within the core.

1. Technical Field of the Invention
The present invention relates generally to bandgap voltage reference generation circuitry realized in CMOS process. More particularly, the present invention relates to a bandgap voltage reference generator with high PSRR and low power dissipation suitable for use with a low voltage supply.
2. Description of Related Art
Reference in now made to FIG. 1 wherein there is shown a circuit diagram of a classical implementation of a bandgap voltage reference generator 10. The generator 10 includes an operational amplifier (OPAMP) 12 having a positive input 14, a negative input 16 and an output 18. A voltage divider is formed by two series connected resistors R1 and R2 which are coupled together at node Y, with node Y being connected to the negative input 16. A first end of the voltage divider is connected to the output 18 of the operational amplifier 12. A second end of the voltage divider is connected to the emitter of a bi-polar transistor Q2. The collector and base of the transistor Q2 are connected to a ground reference. A resistor R3 is coupled between the output 18 of the operational amplifier 12 and node X, with node X being connected to the positive input 14. Node X is further connected to the emitter of a bi-polar transistor Q1. The collector and base of the transistor Q1 are connected to a ground reference, such that the bases of the transistors Q1 and Q2 are connected together.
The OPAMP 12 is needed to make the voltage at nodes X and Y equal and stable. In addition to this, an improvement in PSRR with the OPAMP allows for its wide use in bandgap circuits. In a normal application, the OPAMP is just a basic differential input operational amplifier. However, to improve PSRR in low voltage applications, a high performance with high gain and high speed and low-offset OPAMP is desired. This results in a bandgap circuit that is more complex with a higher power dissipation. Such a circuit is not well suited for use in signal processing applications such as in a data converter.
Given the foregoing, there is an interest in the use of OPAMP-less bandgap generators. However, such circuits are typically not suitable for signal processing applications for a number of reasons.
Reference is now made to FIGS. 2 and 3 which illustrate, respectively, a simple and a cascode OPAMP-less bandgap voltage reference generator circuit known in the prior art.
In FIG. 2, bipolar transistors Q1 and Q2 are connected as in FIG. 1 with their collectors and bases coupled to the ground reference voltage. With respect to the emitter of transistor Q1, it is connected to a supply reference voltage Vdd through the series-connected source-drain circuits of MOS transistors M1 and M3 (where M1 is an n-channel device and M3 is a p-channel device). The gate of transistor M1 is connected to the drain of transistor M1. With respect to the emitter of transistor Q2, it is connected to the supply reference voltage Vdd through the series-connected source-drain circuits of MOS transistors M2 and M4 (where M2 is an n-channel device and M4 is a p-channel device) and series connected resistor R1. The resistor R1 is coupled between the emitter of transistor Q2 and the source of transistor M2. The gate of transistor M4 is connected to the drain of transistor M4. Additionally, the gate of transistor M4 is connected to the gate of transistor M3, while the gate of transistor M2 is connected to the gate of transistor M1. A third bipolar transistor Q3 is provided with its collector and base coupled to the ground reference voltage. With respect to the emitter of transistor Q3, it is connected to the supply reference voltage Vdd through the series-connected source-drain circuit of p-channel MOS transistor M5 and resistor R2. The resistor R2 is coupled between the emitter of transistor Q3 and the drain of transistor M5, with the bandgap output voltage Vbg being taken at the drain of transistor M5. The gate of transistor M5 is connected to the gates of transistors M3 and M4.
In FIG. 3, bipolar transistors Q1 and Q2 are connected as in FIG. 1 with their collectors and bases coupled to the ground reference voltage. With respect to the emitter of transistor Q1, it is connected to the supply reference voltage Vdd through the series-connected source-drain circuits of MOS transistors M1, M1a, M3a and M3 (where M1/M1a are n-channel devices and M3a/M3 are p-channel devices). The gate of transistor M1 is connected to the drains of transistors M1a and M3a. The gate of transistor M1a receives a bias voltage Vb2, and the gate of transistor M3a receives a bias voltage Vb1. With respect to the emitter of transistor Q2, it is connected to the supply reference voltage Vdd through the series-connected source-drain circuits of MOS transistors M2, M2a, M4a and M4 (where M2/M2a are n-channel devices and M4a/M4 are p-channel devices) and series connected resistor R1. The resistor R1 is coupled between the emitter of transistor Q2 and the source of transistor M2. The gate of transistor M4 is connected to the drains of transistor M2a and M4a. Additionally, the gate of transistor M4 is connected to the gate of transistor M3, while the gate of transistor M2 is connected to the gate of transistor M1. The gate of transistor M2a also receives the bias voltage Vb2, and the gate of transistor M4a also receives the bias voltage Vb1. A third bipolar transistor Q3 is provided with its collector and base coupled to the ground reference voltage. With respect to the emitter of transistor Q3, it is connected to the supply reference voltage Vdd through the series-connected source-drain circuits of p-channel MOS transistors M5 and M5a and resistor R2. The resistor R2 is coupled between the emitter of transistor Q3 and the drain of transistor M5a, with the bandgap output voltage Vbg being taken at the drain of transistor M5a. The gate of transistor M5a also receives the bias voltage Vb1. The gate of transistor M5 is connected to the gates of transistors M3 and M4.
The bandgap voltage Vbg is (equation 1):
  Vbg  =            Vbe                                      3        +                            R                                                              2                          R                                                              1                                  V        T                  ln                                      N      wherein N is the aspect ratio of Q2 and Q1.
The effective PSRR is expressed as (equation 2):
  PSRR  =                    Δ                                                  Vin                    Δ                                                  Vbg              =                            Z          gnd                +                  Z                                    i                                                                                n                                                                                Z        gnd            wherein ΔVbg and ΔVin refer to changes in the bandgap reference voltage and the input supply voltage Vdd, respectively, while Zgnd and Zin represent the effective impedance from the reference to the ground node and to the input supply voltage, respectively.
Obviously, Zin is only ro5 and not large enough to achieve high PSRR in FIG. 2. The PSRR is largely improved in FIG. 3 since the cascode is being used to increase the impedance from the reference voltage to the input supply. In this case, it is noted (equation 3):Zin≈gm5aro5ro5a
Other techniques to improve PSRR for OPAMP-less bandgap, such as a regulated cascade technique, also can be adopted, but it is difficult to realize. Even though the PSRR is high for the techniques of FIGS. 2 and 3, it is not high enough for use in a data converter or other high performance application.
In summary, a number of drawbacks have been noted with respect to the traditional bandgap circuit designs for use in data converter and other high performance circuits: 1) the requirements for the OPAMP (see, FIG. 1) are high for an OPAMP bandgap circuit and the dissipation area is increased; and 2) the PSRR is not high enough for OPAMP-less bandgap designs. Even high PSRR OPAMP-less bandgap circuits have drawbacks since their minimum supply voltage is too high and the circuits are not compatible with the standard CMOS process.
A need accordingly exists for a bandgap circuit which overcomes the foregoing drawbacks and is compatible with the standard CMOS process. The circuit should possess high PSRR and a low temperature coefficient. The circuit should preferably be OPAMP-less so as to minimize dissipation. The circuit should also be compatible with low supply voltages.

OPAMP-less bandgap voltage reference with high PSRR and low voltage in CMOS process


A multibeam semiconductor laser diode having: an n-type semiconductor substrate; an n-type clad layer, an active layer, a p-type clad layer and a contact layer; a plurality of partitioning grooves extending from one end to the other end of the substrate and formed from the contact layer to a predetermined depth of the p-type clad layer; a stripe-shaped ridge sandwiched between two separation grooves; an insulating layer covering an area from each side wall of the contact layer of each ridge to an end of the partitioning region via the separation groove; a first electrode formed on a second plane of the substrate; and a second electrode formed in each partitioning region covering an area above the ridge, separation grooves and multilayer semiconductor layers outside the separation grooves, the second electrode being constituted of a lower second electrode layer and an upper second plated layer.

The present invention relates to a semiconductor laser diode of a multibeam structure for emitting laser beams in parallel, its manufacture method and a manufacture method for an opto-semiconductor device. The present invention relates to technologies effective for being applied to manufacture technologies of e.g., a ridge structure semiconductor laser diode.
A semiconductor laser (laser diode: LD) is widely used as a light source of an optical communication system and an information processing apparatus. A visual light optical semiconductor laser is used for CD, DVD, a laser printer, POS, a bar code reader as well as a light source of an information processing apparatus such as a document file system.
A semiconductor laser diode (opto-semiconductor device) has a structure that a number of semiconductor layers (multilayer semiconductor layer) are epitaxially grown on a first surface of a semiconductor substrate. An active layer is disposed as a middle layer of the multilayer semiconductor layer. Of two layers sandwiching the active layer, one layer is a semiconductor layer of a first conductivity type and the other layer is a semiconductor layer of a second conductivity type to thereby form a pn junction. In order to form a resonator (optical waveguide) for laser oscillation, various structures have been adopted such as a narrow electrode and a ridge structure. Since the semiconductor laser diode has an anode electrode (p-electrode) and a cathode electrode (n-electrode), there is adopted a structure that the electrodes are disposed on the same plane side of the semiconductor laser diode or a structure that the electrodes are separately disposed on the front and rear surfaces of the semiconductor laser diode.
A semiconductor laser diode of a ridge structure has two separation grooves formed on the surface of a flat semiconductor layer in order to form a ridge (ridge stripe). Therefore, even in a state that an electrode is formed on the surface of the semiconductor laser diode, the separation grooves and steps of the concave and convex portions of the ridge appear on the surface correspondingly. As a result, if the electrode of the semiconductor laser diode is fixed in a so-called junction down state that the electrode plane is stacked upon a submount, with a soft bonding material such as solder being interposed therebetween, a void is likely to be generated between the submount and semiconductor laser diode due to the concave and convex portions. Although heat generated in the semiconductor laser diode is transferred to the submount via the bonding material, if the void is generated, it is difficult to efficiently transfer heat to the submount (e.g., refer to JP-A-2005-217255).
In the invention described in JP-A-2005-217255, the surface of a plated metal layer formed on the surface of a semiconductor laser diode is planarized to prevent a void from being generated.
A semiconductor laser diode of a so-called multibeam structure is known in which a plurality of resonators are disposed in parallel on a single semiconductor laser diode (also called a semiconductor laser chip) (e.g., refer to JP-A-2002-57401). JP-A-2002-57401 discloses a structure (2-beam structure) that two semiconductor laser diodes are mounted on one chip. The semiconductor laser disclosed in JP-A-2002-57401 has a buried hetero structure different from the ridge structure.
The semiconductor laser diode of the buried hetero structure is formed by using a substrate formed with a stripe-shaped mesa projection. The semiconductor laser has a semiconductor lamination body including a first clad layer of a first conductivity type, an active layer, a second clad layer of a second conductivity type, and a current block layer of the first conductivity type formed on mesa grooves on both sides of the mesa projection and contacting both side walls of the active layer over the whole thickness of the active layer. As an upper layer of the semiconductor lamination body, a first electrode of a structure including an alloying preventive film is formed, and a second electrode is formed on the bottom surface of the substrate. A step caused by a height of the mesa projection is formed on the surface of the semiconductor lamination body. The first electrode has a structure having two alloying preventive films and a stress relaxing layer formed between the two alloying preventive films and made of material softer than the two alloying preventive films.
The following problem occurs when mounting a semiconductor laser structure whose first electrode does not have a structure having two alloying preventive films and a stress relaxing layer formed between the two alloying preventive films and made of material softer than the two alloying preventive films.
Namely, for example, when the semiconductor laser is mounted from the first electrode side on a substrate such as a submount by using solder, a stress is applied from a bonding plane of the first electrode and solder to an operation region having a triangular cross sectional shape and constituted of the first clad layer, active layer and second clad layer respectively on the mesa projection. More in detail, a step is left on the surface of a semiconductor lamination body of the first electrode, corresponding to a height of the mesa projection formed on the semiconductor substrate, and a stress caused by a difference of a thermal expansion coefficient between the submount substrate and semiconductor laser is applied to the operation region so that the laser characteristics such as a polarization direction of a laser beam are influenced.
However, the semiconductor laser whose first electrode has two alloying preventive films can prevent alloying at the interface between the electrode and semiconductor lamination body or at the interface between the electrode and solder, in the area of the alloying preventive films. Further, by disposing the stress relaxing layer of Au or the like softer than the alloying preventive films at the position where alloying progress is to be prevented, it becomes possible to relax a stress to be caused by a difference of a thermal expansion coefficient between the substrate and semiconductor laser. As a result, even the structure that two semiconductor laser diodes are mounted on one chip, it is possible to prevent influence upon the laser characteristics such as a polarization direction of a laser beam.
A semiconductor laser diode of a multibeam structure is used as a light source of a plane paper copier (PPC) and a laser beam printer (LBP). A multibeam laser is required that each beam has uniform polarization characteristics. However, in practice, each beam has a variation in characteristics, and mitigating this variation is a technical issue inherent to a multibeam laser.
The variation mainly results from the following. (1) A size variation in a wafer process of manufacturing a semiconductor laser diode generates a variation in characteristics.
(2) A semiconductor laser device is made of compound semiconductor, and on the surface of the device, an insulating film such as an SiO2 film and an electrode made of metal are formed. A stress (inner stress) is generated in the diode (chip) due to a difference of a thermal expansion coefficient between the insulating film and electrode, and this inner stress generates a variation in characteristics.
(3) A semiconductor laser diode is fixed to a submount (supporting base plate) made of aluminum nitride (AlN) and also fixed to a heat sink made of metal such as copper. A thermal stress is generated due to differences of linear thermal expansion coefficients of compound semiconductor, aluminum nitride (AlN) and the like, and metal and the like. This thermal stress generates a variation in characteristics.
The factors (2) and (3) in particular of generating a stress influence greatly the polarization characteristics. A variation in characteristics can be improved by relaxing the stress variation.
According to the comparative experiments made by the inventor, in a structure (so-called junction down mount) that a second electrode formed on a multilayer semiconductor layer including an active layer is stacked upon and bonded to a submount by using a soft bonding material such as solder, stresses particularly stresses near the mount plane of the semiconductor laser chip are dominant. A semiconductor laser diode of a ridge structure has a structure having a separation groove on both sides of a ridge, and two cavities corresponding to the separation grooves appear on the surface of the second electrode. Therefore, when the semiconductor laser is mounted on a submount (supporting base plate) by using a bonding material, it is difficult for the bonding material to reliably enter the cavities corresponding to the separation grooves, so that voids are generated at the interface between the second electrode plane and bonding material. It has been clarified that these voids apply stresses to an active layer region corresponding to the ridge, in other words, a resonator region, and a variation in polarization angles occurs. Namely, as voids are generated, uniformity (balance) of stresses applied to the ridge region from the submount and bonding material is broken, and rotation of a polarization angle occurs.
FIGS. 19A and 19B are schematic diagrams showing a state of mounting on a submount substrate a semiconductor laser diode of a ridge structure studied prior to the present invention. FIG. 19A is a diagram showing a state before the semiconductor laser diode is mounted on the submount, and FIG. 19B is a diagram showing a state after the semiconductor laser diode is mounted on the submount.
FIG. 19A shows a submount 70 and a semiconductor laser diode 75 to be mounted on a first plane 70a of the submount 70. The submount 70 is a flat plate body made of aluminum nitride (AlN) or the like, and an electrode pad 71 having a predetermined pattern is disposed on the first plane 70a. The electrode pad 71 is made of, e.g., an Au layer having a thickness of about 0.5 to 1.0 μm. A soft bonding material 72 is formed on the electrode pad 71. The bonding material 71 is made of, e.g., solder such as AuSn having a thickness of about 3 to 5 μm.
In order to mount the semiconductor laser diode 75 on the submount 70 in junction down, there is shown in FIGS. 19A and 19B a state that a first plane 76a of a semiconductor substrate 76 of a first conductivity constituting the semiconductor laser diode 75 is positioned at a lower plane, and that a second plane 76b as an opposite plane of the first plane 76a is positioned at an upper plane. On the first plane 76a of the semiconductor substrate 76, a multilayer semiconductor layer is formed by sequentially laminating a first conductivity type clad layer 77 of the first conductivity type, an active layer 78, a second conductivity type clad layer 79 of a second conductivity type and a contact layer 80 of the second conductivity type.
On the surface of the multilayer semiconductor layer, three or more partitioning groves 81 are formed extending from one end to the other of the semiconductor substrate 76 (e.g., from a front side to the back side of the drawing sheet) and from the surface of the contact layer 80 to a predetermined depth of the second conductivity type clad layer 79. In the drawing, two partitioning groove 81 are shown.
Two separation grooves 83 are formed in a central region of a partitioning region 82 sandwiched between the adjacent partitioning grooves 81. Similar to the partitioning groove 81, the separation groove 83 is formed extending from one end to the other of the semiconductor substrate 76 and from the surface of the contact layer 80 to the predetermined depth of the second conductivity type clad layer 79. A stripe-shaped convex region sandwiched between two separation grooves 83 is a ridge 84. Multilayer semiconductor layer regions outside the separation grooves 83, i.e., regions sandwiched between the separation grooves 83 and partitioning grooves 81 are called a field region 85.
On both sides of the ridge 84, an insulating layer 86 is formed covering the area from each side wall of the contact layer 80 of the ridge 84, via the separation groove 83 to the end of the partitioning region 82. A first electrode 91 is formed on the second plane 76b of the semiconductor substrate 76. The first electrode 91 is constituted of a first electrode layer 92 as an underlying layer and a first plating layer 93 formed on the first electrode layer 92.
On the side of the first plane 76a of the semiconductor substrate 76, a second electrode 95 is formed. The second electrode 95 is formed above the surface of the partitioning region 82, covering the areas above the ridge 84, above the separation groove 83 on both sides of the ridge 84, and above the field regions 85 (multilayer semiconductor layer regions outside the separation grooves 83). The second electrode 95 is constituted of a second electrode layer 96 as an underlying layer and a second plating layer 97 formed on the second electrode layer 96. The first and second electrode layers 92 and 96 are each a layer formed by sequentially laminating a Ti layer, a Pt layer and an Au layer by evaporation, and are each made of Au having a thickness of about 0.3 to 0.5 μm. The first and second plated layers 93 and 97 are each an Au layer having a thickness of about 3 to 5 μm formed by a plating process.
The semiconductor laser diode 75 shown in FIG. 19A is held by an unrepresented holding tool such as a collet, positioned above the submount 70, and lowered as indicated by an arrow to be stacked upon the submount 70. The semiconductor laser diode 75 is therefore mounted on (fixed to) the submount 70, as shown in FIG. 19B. During fixing, since the grooves are formed on the surface of the second electrode 95 in correspondence with the separation grooves 83, there is a high possibility that air remains in the grooves when the second electrode 95 is pushed against the bonding material 72, even if the melted bonding material 72 invades into the grooves. Remaining air forms an air bubble (void) 98. Since the semiconductor laser diode 75 generates heat during laser oscillation, a high temperature state of about 80° C. occurs. As the air bubble 98 is generated at the interface between the second electrode 95 and bonding material 72, uniformity (balance) of stresses applied to the ridge 84 having a narrow width of about 1 to 3 μmn is broken, resulting in rotation of a polarization angle. As shown in FIG. 19B, stresses indicated by arrows are applied, for example, to the center of the ridge 84 from both sides of the ridge 84, depending upon a difference of thermal expansion coefficients of various materials. In this case, in the region where the air bubble (void) 98 is generated, the air bubble region functions as a buffer, so that a stress indicated by an arrow directing from right to left is smaller than a stress indicated by an arrow directing from left to right. The arrow directing from right to left is shown shorter than the arrow directing from left to right, indicating a smaller stress. As uniformity (balance) of stress is broken, rotation of a polarization angle occurs.
FIG. 18 is a schematic diagram showing a polarization angle α. FIG. 18 is a plan view showing a state that a cap fixed to a first plane of a stem 100 is dismounted. A heat sink 101 having a rectangular solid shape is fixed to the central area of the first plane of the stem 100. A submount 70 is fixed to the side wall of the heat sink 101 on the center side of the stem 100. A laser beam 102 is indicated by a black circle and emitted from a facet (emission plane) of the semiconductor laser diode 75. A plane having arrows at opposite ends in FIG. 18 is a polarization plane 103, and an angle between the polarization plane 103 and a plane along an extension direction of an unrepresented active layer of the semiconductor laser diode 75 is the polarization angle α.
Even a semiconductor laser diode having a single resonator, if semiconductor laser diodes have a variation in polarization angles, the semiconductor laser diodes cannot be used, because desired characteristics cannot be obtained if an optical component has polarization angle dependency.
In the case of a semiconductor laser diode of a multibeam structure that the semiconductor laser diode has a plurality of resonators disposed in parallel, if there is a variation in polarization angles of laser beams emitted from respective resonators, the semiconductor laser diode cannot be used for an electronic apparatus such as a plain paper copier (PPC) and a laser beam printer using a semiconductor laser diode of the multibeam structure as its light source.
The semiconductor laser of JP-A-2005-217255 has a structure that the upper surface of the plated metal layer formed on the upper surface side of the ridge stripe region is planarized in order to prevent heat radiation from being lowered by generation of a void. However, if the structure of the flat upper surface of the plated metal layer has a structure that the flat plane of the plated metal layer is stacked upon the solder on the heat sink and the semiconductor laser is fixed by heating, melting and bonding, there is specifically no function of pushing air existing at the interface in the stacked state to the peripheral edges of the plated metal layer. Therefore, air may be left and an air bubble (void) is generated at the bonding interface. Further, although the surface of the plated metal layer is flat, if the surface of the solder is flat, the flat plane is stacked upon the flat plane so that an area not wetting the solder may be formed depending upon manufacture variation.
In a semiconductor laser diode of the multibeam structure that a plurality of resonators exist in parallel on the semiconductor laser diode, there are as many bonding regions by solder between the submount and electrode as the number of resonators so that a possibility of generating an air bubble (void) becomes high. A polarization angle of a laser beam emitted from the resonator having a generated air bubble becomes different from that of the other laser beams. This semiconductor laser diode cannot be used as a light source of an electronic apparatus having an optical component with polarization angle dependency.

Semiconductor laser diode and the manufacturing method thereof


A method, article of manufacture, and apparatus for restricting the receipt of automatic delegate reply messages. Specifically, the method configures a control message for an electronic mail (e-mail) message addressed to at least one recipient terminal or computer, and sends the e-mail and control messages to the at least one recipient terminal. Upon processing the control message, the at least one recipient terminal determines whether to reply to the received e-mail message with a delegate reply message. As such, a sender of the e-mail message may restrict the receipt of delegate reply messages by configuring the control message through different features or options.

1. Field of the Invention
The invention relates to electronic mail systems and, more particularly, the invention relates to a method, article of manufacture and apparatus for restricting the receipt of delegate reply messages.
2. Background of the Related Art
In today's electronic mail (e-mail) environment, many users utilize a delegate reply feature while away on vacation or business. This delegate reply feature may automatically create and send a delegate reply message in response to a sent message. The delegate reply message notifies the sender that the user, i.e., the recipient of the sent message, is unavailable or not present, and generally provides a reason for their absence.
Although the delegate reply message is useful to the recipients of the sent message, the delegate reply message also contributes to extraneous messages or clutter to the sender. When the message is sent to a large audience, this cluttering problem is exacerbated if the recipients in the audience use the automatic delegate reply feature. In this situation, extra effort is required by the sender to clean up the delegate reply messages. As such, the large amount of delegate reply e-mail received would discourage the sender from sending messages to such a large audience.
Therefore, a need exists in the art for a method, article of manufacture and apparatus prevent this cluttering problem by restricting the receipt of delegate reply messages.

Method, article of manufacture and apparatus for restricting the receipt of delegate reply messages

International Business Machines Corporation


An attachment for attaching a main circuit breaker in an electrical panel has a uniquely constructed hold-down for the circuit breaker and a headed screw for fastening the hold-down in the panel. The hold-down is a non-electrically conductive part, such as a plastic. A circuit-breaker-engaging projection for engaging a circuit breaker projects from a first side of the hold-down body and a gripping tab projects from a second side of the body opposite the first side. A shank of the headed screw passes through a through-hole in the hold-down body to thread into a hole in a base pan. The screw is tightened against the hold-down body to hold it, and in turn the main circuit breaker, in place. In such an installed condition, the main circuit breaker cannot be removed easily from the panel unless the screw is intentionally unscrewed by a tool sufficiently to allow movement of the hold-down to a position that enables the main circuit breaker to be removed. The hold-down includes certain features that are intended to reduce the risk that the tool might contact parts other than the screw and the hold-down during unscrewing. The gripping tab facilitates installation and removal, and provides an obstruction to any attempted installation of one or more extra distribution circuit breakers in a vacant space along side the main circuit breaker that is being held in place by the hold-down.

Commonly-owned, pending U.S. patent application Ser. No. 08/622,971 filed March 1996, discloses an electrical panel containing an electrically non-conductive basepan for two rows of back-fed circuit breakers. Each of two respective bus bars is disposed on a respective half of a front facing surface of the basepan and connected to an incoming hot feed that is brought into the panel from the electric power utility by one or more incoming hot cables. The two bus bars are separated from each other by a serpentine wall that is present on the basepan between the two bus bars. Each bus bar contains a number of stabs that collectively are arranged in respective rows, and each of which points in a direction toward the deadfront. The serpentine wall has a shape that winds between the stabs of one bus bar and those of the other. A respective back-fed distribution circuit breaker fits onto a respective stab of a bus bar to establish electric connection of the bus bar to the hot side of the circuit breaker. A load wire of each distribution circuit that is served by the electrical panel is attached to the load side of a respective distribution circuit breaker. Neutral bars on the base pan provide for the connection of individual neutral return wires of the respective distribution circuits to a neutral that is brought into the panel from the electric power utility by one or more incoming neutral cables and connected to the neutral bars.
One type of electrical panel has a main circuit breaker through which the incoming hot feed is connected to the distribution circuit breakers. Such a main circuit breaker, like the distribution breakers, is selectively operable to on and off positions. When operated to its on position, it is effective to conduct the hot feed to the distribution circuit breakers, and when operated to its off position, it is effective to shut off the hot feed to the distribution circuit breakers.
In certain electrical panels of this type that have distribution circuit breakers arranged in side-by-side rows as described above, it is believed that there is some benefit in arranging the main circuit breaker in one of the two rows. Such a main circuit breaker may comprise a profile that is essentially like that of the distribution circuit breakers in the same row for fitting to a base pan, the fitting of the distribution circuit breakers to the base pan.
Attachment of such a main circuit breaker to an electrical panel may have to comply with certain applicable standards. For example, one potentially applicable standard provides that before it becomes possible to remove an installed main circuit breaker from a panel, a manual operation must be performed on an attachment that holds the main circuit breaker in place. Such a standard may concern inadvertent, or unintentional, removal of a main circuit breaker from a panel. The manual operation performed on the attachment is generally done with forethought.
It may be desirable to organize and arrange an electrical panel so as to make it more difficult to circumvent potentially applicable standards. For example, a panel that is designed to have two rows of circuit breakers, including a main circuit breaker in one of the rows, may be designed for a maximum number of distribution circuit breakers in each row. In such a design, the row that does not contain the main circuit breaker may have vacant space in the location that is side-by-side with the main circuit breaker. If such a panel is designed to accommodate equal numbers of distribution circuit breakers in each row that add up to the maximum number allowed by a potentially applicable standard, compliance with such a standard may be achieved either by the placement of a prominent warning against attempting to install additional distribution circuit breakers in such vacant space, and/or by mechanically making it more difficult to install extra distribution circuit breakers in the vacant space.
The present invention is directed to a novel attachment for a main circuit breaker that is believed to address concerns such as those just discussed.
A presently preferred embodiment of the invention relates to a main circuit breaker attachment comprising first and second parts, wherein the first part is believed to be a uniquely constructed hold-down for the circuit breaker and the second part is a headed screw for fastening the hold-down in the panel. The hold-down is a non-electrically conductive part, such as a suitably molded plastic. The hold-down engages the main circuit breaker, and a shank of the headed screw passes through a through-hole in the hold-down to thread into a hole in the base pan. The screw is tightened against the hold-down to hold it, and in turn the main circuit breaker, in place. In such an installed condition, the main circuit breaker cannot be removed at least easily from the panel unless the screw is first sufficiently loosened, and perhaps even removed from the hold-down, to allow movement of the hold-down to a position that enables the main circuit breaker to be removed. Because unfastening of the attachment screw may involve the use of a hand tool such as a screwdriver, the hold-down includes certain features that are intended to minimize or at least reduce the risk that the tool might contact parts other than the attachment screw and the hold-down during the process of unfastening the attachment screw. The hold-down further includes a finger-grippable tab that is designed both to facilitate installation and removal, and to provide an obstruction to any attempted, potentially non-compliant, installation of one or more extra distribution circuit breakers in vacant space along side the main circuit breaker that is being held in place by the hold-down. The tab may be provided with further useful features, such as texturing or ribbing to facilitate gripping, and informational and/or warning indicia. The hold-down may also be distinctively colored as a potential aid in directing a person's attention to it so that the presence of a main circuit breaker in a panel may be better recognized.
One object of the invention is to provide an electric distribution panel through which incoming electric power is distributed through circuit breakers to individual distribution circuits, the panel comprising: a main circuit breaker through which incoming electric power passes; a number of individual distribution circuit breakers; first and second bus bars for delivering incoming electric power from the main circuit breaker to the individual distribution circuit breakers; an attachment for attaching the main circuit breaker to the panel that requires performance of a manual operation before the main circuit breaker can be detached from the panel; the attachment comprising a first part and a second part; the first part having an association with the main circuit breaker, when the first part is disposed in an attached position, to prevent the main circuit breaker from being detached from the panel; the second part having an association with the first part, when the first part is in attached position and when the second part is in an attaching position, that keeps the first part in attached position; and the second part being operable by a manual operation from attaching position to a non-attaching position to allow the first part to move to a non-attached position that ceases to at least better prevent the main circuit breaker from being detached from the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the main circuit breaker comprises two side-by-side conjoined circuit breakers, and the first part comprises a body with which the second part has association and a projection projecting from the body to fit between the side-by-side conjoined circuit breakers that at least better prevent them from being detached from the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a through-hole and the second part comprises a fastener that acts via the through-hole to hold the first part in the panel.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the fastener comprises a screw having a head that bears against the body and a threaded shank that extends from the head through the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a frontally facing surface against which the screw head bears and a wall extending frontally from the frontally facing surface and circumferentially bounding at least a portion of the screw head.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a walled well having a frontal opening disposed adjacent the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the wall extending frontally from the frontally facing surface and circumferentially bounding at least a portion of the screw head fully circumferentially bounds both the screw head and the frontal opening of the well.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the projection projects laterally from a first side of the body, and the body includes a further projection projecting from a second side of the body opposite the first side.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the further projection comprises a tab occupying a plane that is skewed to the length of the through-hole.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the further projection comprises a tab that has a size sufficient for gripping between a person's thumb and forefinger.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the first part comprises a body having a circuit-breaker-engaging projection at a first side of the body engaging the main circuit breaker and a tab projecting from a second side of the body.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the first and second sides of the body are disposed opposite each other and the tab extends at an angle frontally of the body.
Still another object of the invention is to provide an electric distribution panel as set forth above wherein the body comprises a through-hole and the second part comprises a fastener that acts via the through-hole to hold the first part in the panel.
Still another object of the invention is to provide a hold-down for use in attaching a circuit breaker to an electrical panel comprising a non-electrically conductive body, a circuit-breaker-engaging projection at a first side of the body for engaging a circuit breaker and a gripping tab projecting from a second side of the body.
Still another object of the invention is to provide a hold-down as set forth above wherein the first and second sides of the body are disposed opposite each other and the gripping tab extends at an angle frontally of the body.
Still another object of the invention is to provide a hold-down as set forth above wherein the body comprises a through-hole having an entrance at a frontal surface of the body that is disposed between the first and second sides.
The foregoing, along with further features, advantages, and benefits of the invention, will be seen in the ensuing description and claims, which are accompanied by drawings. The description and drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention.


A high-frequency stabilization network for microwave devices and monolithic integrated circuits. The stabilization network may comprise one or more monolithic RL parallel networks, configured to reduce in-band high-frequency oscillation, such as Gunn effect oscillation and IMPATT oscillation.

Transistors and amplifier circuits based on III-V compound semiconductors (i.e., GaAs MESFET, GaAs pHEMT, In PHEMT, GaAs metamorphic HEMTs) are prone to high-frequency oscillation (known as Gunn oscillation) due the negative differential resistance of the velocity-field curve, which generates a traveling Gunn domain propagation, resulting in negative resistance in the drain output. Although the effect has been used for microwave/millimeter-wave generations, it is an undesirable phenomenon for the stable and efficient operation of power amplifiers. Under RF drives, this high-frequency oscillation can manifest itself as spurious signals at undesirable out-of-band frequencies. For high power microwave systems (i.e., for radar applications), the frequency spectrum needs to be spurious free at all frequencies and also near the carrier.
There is currently no effective way at the circuit level to suppress these undesirable oscillations in-band. For instance, conventional reflective filters operate out-of-band. There is desired a method of high-frequency suppression in a simple stabilization circuit monolithically integratable in a MMIC amplifier. Even though Gunn oscillation is cited as the main contributor to the negative drain output resistance, other types of high-frequency oscillations, such as IMPATT oscillation, are also desired to be effectively suppressed.

High frequency stabilization network for microwave devices and monolithic integrated circuits


A relay optical system is disclosed that comprises, in axial order from the object side, first, second, third, and fourth lens groups having a negative, a positive, a positive, and a negative refractive power, respectively. An aperture stop is between the second and third lens groups. Relative to the aperture stop, the first lens group is symmetrical with the fourth lens group and the second lens group is substantially symmetrical with the third lens group. The relay optical system fulfills at least the conditions:. -0.3<f/f1<-0.1 PA1 0.5<f/f2<1.1. wherein f1 and f2 are the focal lengths of the first and second lens groups, respectively, and f is the overall focal length of the relay optical system.

Video projectors are known that employ a CRT (cathode-ray tube) or transmitting liquid crystal light valve as the source of a projected image. Also, high-definition versions of such image sources have been realized.
Unfortunately, conventional video projectors for such high-definition image sources are unsatisfactory especially due to the difficulty in achieving a desired high level of brightness and definition of the projected image using such projectors.
Video projectors have been realized that employ optically addressed spatial light modulators as a means for improving the brightness and definition of the projected image on a screen. In these systems, a video image is "written" on a liquid crystal layer by conducting an original image (formed on a CRT or analogous device) onto a spatial light modulator (SLM). Light from a light source is impinged on the liquid crystal layer "imprinted" with the image; light (containing the image) reflected from the liquid crystal layer is then projected onto a viewing screen using a projection lens.
To "write" the image on the spatial light modulator, an optical fiber array or optical relay is disposed between the image source and the spatial light modulator. Use of an optical fiber array as an image-conducting means advantageously is amenable to miniaturization. Unfortunately, however, an optical fiber array has the still unsolved problem of introducing "chicken wire" artifacts on the image and also is expensive.
Conventional optical relays can also be made small and can be used at full magnification. However, for optimal performance, the optical relay must be able to transmit a bright image in order to effectively drive the spatial light modulator. It has heretofore been very difficult to realize an optical relay that conducts a bright image and that produces high image quality at full magnification.


A zoom lens includes a first lens group with a negative refractive power and a second lens group with a positive refractive power. The first lens group includes a first lens, a second lens, a third lens and a fourth lens arranged in sequence and refractive powers thereof are negative, negative, negative and positive respectively. The first and second lenses are meniscus lenses and two surfaces of the second lens are aspheric surfaces. The third lens is a biconcave lens and the fourth lens is a biconvex lens. The second lens group includes a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens arranged in sequence and refractive powers thereof are positive, positive, positive, negative and positive respectively. A cemented doublet lens is composed of the seventh and eighth lenses. The ninth lens is a biconvex lens.

1. Field of the Invention
The present invention relates to a lens, and more particularly to a zoom lens.
2. Description of Related Art
To attain the advantages of wide angle and small size, a zoom lens is normally designed to have two lens groups in the conventional technique. A first lens group, which is closer to an object side, has a negative refractive power and a second lens group has a positive refractive power. In other words, the first lens group is used for diverging light beams and the second lens group is used for converging light beams.
However, an f-number of the conventional wide-angle zoom lens comprising two lens groups is greater than 3.5. Hence, it is difficult to reach a large relative aperture. In addition, eliminating distortion is difficult while this type of zoom lens is in a wide-end disposition. The conventional technique usually relies on two methods for minimizing the distortion. One of the methods includes distancing the positive lens in the first lens group or the negative lens in the second lens group away from the aperture stop. However, this method not only increases the dimension of the first lens group or the second lens group, but overall length of the zoom lens also increases as well so that it is harder to form a compact structure. The other method is to increase the refractive power of the positive lens in the first lens group or the negative lens in the second lens group. If the refractive power of the positive lens in the first lens group is increased, the refractive power of the other negative lenses in the first lens group must be increased. Hence, high-level distortion aberration and coma aberration is produced leading to a deterioration of overall image quality. A similar condition occurs when the refractive power of the negative lens in the second lens group is increased.


A seal for a gap between an outer and an inner cylindrical surface, coaxial with a central axis in common and arranged to rotate reciprocally, the seal comprises a plurality of plate elements stacked onto one another to define a ring between the outer and inner cylindrical surfaces, wherein each plate has a concave and a convex side, the convex side of each plate element being adjacent to the concave side of the next plate element.

The present disclosure relates to a seal for a gap between an outer and an inner cylindrical surface. The surfaces have a central axis, are coaxial and are arranged to rotate reciprocally. Specifically, the disclosure relates to an internal seal for a turbomachine, for example a seal between a rotating shaft and an external case holding a working fluid. In the following disclosure centrifugal pumps will be referred as a specific application of the disclosure; no loss of generality is however intended.
In the state of the art, a seal for the above mentioned gap can be provided by closely packing a plurality of flat plates. These plates are arranged radially. In other words, the plates are arranged so that they lay on a plane containing the central axis of the surfaces. The length, the thickness and the number of plates are selected so that only small gaps are present between two neighboring plates. These gaps allow a small leakage of working fluid. The leakage is deemed acceptable, because it contributes to the lubrication of the reciprocally moving surfaces.
Disadvantageously, if the cylindrical surfaces have small radii compared to their reciprocal distances, relatively large gaps can result between plates near the external cylindrical surface. These large gaps (about 0.1-0.3 mm) will tend to cause excessive leaks of fluid. Also, may be subject to problems (loss of flexibility and consequent rubbing) if contaminated by entrapped solid particles.

Seal for a gap between an outer and an inner cylindrical surface


An image processing device is provided, which has the capability of accurately recognizing the outline of a moving target from at least four still images taken in times series without using a background image not including the moving target. This device comprises a first operation unit for outputting a processed outline image by use of a reference image taken at a reference time, a pair of images taken at first and second times other than the reference time, a second operation unit for outputting a processed outline image by use of the reference image and an image taken at a third time different from the reference time, the first time and the second time, and an outline extracting unit for extracting the outline of the moving target from these processed outline images.

1. Field of the Invention
The present invention relates to an image processing device for recognizing the outline of a moving target such as human and vehicle from a plurality of still images.
2. Disclosure of the Prior Art
In the past, an image processing device using a background subtraction method or a frame subtraction method has been proposed to recognize a moving target such as human and vehicle. In these methods, image processing is performed to grayscale images, and outline images are used to minimize the influence of a change in brightness such as lighting.
The principle of the image processing device according to the background subtraction method is explained in brief referring to FIG. 11. In this image processing, a background image (α) including no moving target is previously taken, and stored. Then, a plurality of images (β) each including the moving target are taken in time series. Each of the obtained images is converted into a binary outline image by use of a SOBEL operator, and stored. By determining a difference between a required outline image and the background image, a region having a predetermined amount of change therebetween is recognized as the region corresponding to the moving target (X).
However, the step of previously preparing the background image is a messy step. In addition, in a case of using an average of the images taken within a required time period as the background image, when the moving target is in a state of rest within the time period, a recognition error of the moving target may occur from the subsequent image processing. This becomes a cause of decreasing the reliability of the image processing device.
As another image processing device using the background subtraction method, Japanese Patent [Early] Publication No. 6-337938 discloses an image processor and a distance measuring device. In this image processing, a first image that is a background image including no moving target, a second image including the background and a moving target with a first speed or less, and a third image including the background and another moving target with a second speed or less are used. A difference between the first and second images is determined to obtain a first subtraction image. Similarly, a difference between the second and third images is determined to obtain a second subtraction image. In addition, a difference between the third image and an image provided by an image input means is determined to obtain a third subtraction image. According to the first to third subtraction images, motions of the moving targets with different speeds can be analyzed at a video rate.
Since this image processor uses the background subtraction method, the messy step of previously preparing the background image is still needed. In addition, since it is difficult to precisely generate the backgrounds of the first to third images, there is a fear of deteriorating the accuracy of analyzing the motions of the moving targets with different speeds. Moreover, there is another problem that this image processing is sensitive to a change in brightness.
On the other hand, the principle of the image processing device according to the frame subtraction method is explained in brief referring to FIG. 12. In this image processing, a subtraction |(T)−(T−ΔT1)| between first and second images taken at different times (T, T−ΔT1) is calculated, so that a region with a predetermined amount of change therebetween is recognized as the region corresponding to the moving target.
According to this method, the step of previously preparing the background image is no longer necessary. However, in the case of determining the absolute-value subtraction, the outline of the moving target (X) may be extracted such that two outlines partially overlap with each other, as shown in FIG. 12. On the other hand, in the case of determining a saturated subtraction, the problem of the absolute-value subtraction can be solved. However, when is a negative value is obtained by the subtraction, it is regarded as zero. Therefore, when an outline of the background hidden by the target appears in the image by a movement of the target, there is a problem that the outline of the background (Y) is accidentally extracted together with the outline of the moving target (X), as shown in FIG. 13.
As another image processing device using the frame subtraction method, Japanese Patent [Early] Publication No. 2000-82145 discloses an object extraction device of recognizing the moving target from three images taken in times series. In this image processing, a set of first, second and third images each including the moving target are taken at different times (T−ΔT1, T. T+ΔT1). From the frame subtractions between the first and second images and between the second and third images, a pair of subtraction images are obtained. In each of the subtraction images, a background region is determined, so that the remaining region is selected as a candidate region of the moving target. Finally, by determining an intersection of the candidate regions, the outline of the moving target at the time (T) can be extracted.
However, when the moving target is parts of the human body such as arms and legs, there is a case that the parts with motions at the first time are different from them with motions at the second time, and similarly the parts with motions at the second time are different from them with motions at the third time. In such a case, the outline extracted by the frame subtraction between the first and second images becomes different from the outline extracted by the frame subtraction between the second and third images. As a result, the outline obtained by determining the intersection of the candidate regions may lose a considerable part of the outline of the moving target to be extracted.
Thus, from the viewpoint of further improving the accuracy of recognizing the moving target without including the background information, there is still room for improvement in conventional image processing devices.

Image processing device for recognizing outline of moving target and method therefor


A karaoke apparatus produces a karaoke accompaniment which accompanies a singing voice of an actual player, and concurrently creates a harmony voice originating from a virtual player. In the karaoke apparatus, a memory device stores voice information of the virtual singer. An input device collects the singing voice of the actual player. An analyzing device analyzes an audio frequency of the collected singing voice. A synthesizing device processes the stored voice information based on the analyzed audio frequency to synthesize the harmony voice having another audio frequency which is set in harmony with the analyzed audio frequency. An output device mixes the collected singing voice and the synthesized harmony voice with each other, and outputs the mixed singing and harmony voices along with the karaoke accompaniment. In one preferred embodiment, the memory device stores the voice information in the form of a sequence of phonetic elements that are successively sampled syllable by syllable from a singing voice of the virtual player.

The present invention relates to a karaoke apparatus constructed to add a harmony voice to a karaoke singing voice, and more particularly to a karaoke apparatus capable of creating a virtual harmony voice resembling a voice other than that of an actual karaoke singer, for example, a voice of an original singer of the karaoke song.
In the prior art, to cheer up the karaoke singing and to improve the karaoke performance, there is known a karaoke apparatus which adds a harmony voice, for example, third degrees higher than a main melody, to the voice of the karaoke singer, and which reproduces the mixed harmony voice and singing voice. Generally, such a harmonizing function is achieved by shifting a pitch of the singing voice picked up through a microphone to generate a harmony sound in synchronization with a tempo of the singer. However, in the conventional karaoke apparatus, the generated harmony voice has the same tone as that of the karaoke singer's actual voice, so that the singing performance tends to be plain. It is hard to fulfill the desire of the karaoke singer that he or she wants to sing with the original singer of the karaoke song.

Karaoke apparatus using frequency of actual singing voice to synthesize harmony voice from stored voice information


When torque transmission through the transmitting torque variable mechanism (e.g., an assist clutch) is changed to torque transmission through a meshing gearing after the gearshift, a controlled variable per unit time when the transmitting torque variable mechanism is released is determined or varied according to the vehicle operating condition after a gearshift has been completed. A degraded gearshift feel as a result of axle vibration at the end of the gearshift can thereby be suppressed.

The present invention relates to a control method and a control system for an automatic transmission.
A motor vehicle with a manual transmission offers better fuel economy as compared with a motor vehicle mounted with a transmission using a torque converter. It is, however, difficult in such a motor vehicle as that with the manual transmission to manipulate a clutch and an accelerator in a coordinated manner when getting the motor vehicle started. If the coordinated operations of the clutch and the accelerator do not go well when the vehicle is started, a large shock occurs as the clutch is engaged. If there is a short supply of a clutch pressure, the engine speed rises sharply, which is commonly referred to as a "revving up phenomenon." If the clutch is quickly engaged when the engine speed is yet to reach a sufficient level, or when the vehicle is started on an uphill slope, the engine can stall.
To solve these problems, a system that automates the clutch and a gearshift using a manual transmission mechanism has been developed. The system is what is called an automated manual transmission, or automated MT.
The conventional automated MT has the disadvantage that there is an interruption of a driving torque occurring from release and engagement operations of the clutch during control for gearshifts. This can at times give passengers of the vehicle a sense of discomfort.
A vehicle provided with an automatic transmission has been proposed to avoid the torque interruption during the gearshift. A known approach to the problem is an assist clutch serving as a transmitting torque variable mechanism provided for the conventional automated MT (see, for example, Japanese Patent No. 2703169). The assist clutch provides control, during a gearshift, for synchronizing rotations and transmitting torque properly for the gearshift. In a vehicle such as that described above, an assist clutch torque release control is provided. In the assist clutch torque release control, after the gearshift to a new meshing gearing has been completed, torque transmitted by the assist clutch is reduced, while torque transmitted by the new meshing gearing after the gearshift is increased.
When the torque transmission through the assist clutch is changed to the torque transmission through the meshing gearing after the gearshift, torque vibration in a transmission output can occur due to a torque step depending on how the assist clutch is controlled. The assist clutch, on the other hand, transmits torque through slippage. This presents a durability problem arising from a quantity of heat generated.

Transmission, and control system and control method for the transmission


Disclosed is a mat for exercise. The mat comprises a main mat having a foot hanger for a sit-up at a top surface of one side thereof and a plurality of grooves at a bottom surface of both lateral sides thereof, a plurality of sub-mats coupled with the main mat in use, and a plurality of attachment plates installed at corners of a bottom surface of the main mat and corners of bottom surfaces of the sub-mats, wherein the main mat is provided with female fabric hook-and-loop fastener (e.g., Velcro) tapes mounted at the grooves thereof, and the sub-mat is provided with male fabric hook-and-loop fastener (e.g., Velcro) tapes that laterally protrude corresponding to the grooves of the main mat.

In general, a mat for floor exercise uses coil-type compression springs to provide elasticity. The compression springs may damage a floor and a board of a gymnasium having the mat installed therein. When the mat is used for a long period of time, noise may occur due to the compression springs. Further, in order to attach the compression springs to the bottom surface of the board, a spring fixing tool must be additionally provided. Furthermore, a process for exchanging a damaged spring is complicated.
In a case in which boards equipped with springs are fixedly connected to each other, since an impact load generated when a player lands on a mat during the floor exercise is transferred to the whole area of the boards, elasticity to be taken by the player is reduced. Thus, the player cannot sufficiently exhibit his/her skill.
At the present time, a cushion is provided by placing scrolls on the board. However, the cushion board may be partially contracted and deformed when it is used for a long period of time, so a player performing the floor exercise may lose the balance. And, in that case, large portion of the cushion board has to be replaced at the same time.
Conventionally, carpets are coupled with each other by means of heat bond tapes. However, if an impact is applied to the heat bond tape in a state where the temperature and moisture are low, the gluey component of the heat bond tape is broken. Further, if the heat bond tape adheres to the carpet once, the heat bond tape cannot be easily detached from the carpet.
Although a sit-up is a kind of free exercise having a superior exercise effect, an assistant for fixing the ankle of a player or an additional tool for grasping the foot of the player is required for the sit-up, causing inconvenience to the player. Thus, many people unconsciously avoid the sit-up.
In addition, a mat generally used in sports and fitness clubs is of small size suitable for only one person, so it is inconvenient for many people to use it in a group.