An optical transmission equipment in an optical communication system interconnecting two optical transmission equipment sets by a main transmission line and a backup transmission line. An optical amplifier amplifies and outputs optical signals from one transmission line in use, interconnecting the optical transmission equipment concerned with neighboring upstream optical transmission equipment, and outputs the optical signals including a signal component and a noise component. A controller controls an optical signal level so that a signal component in the optical signal reaches a predetermined level. The controller corrects the optical signal level when the transmission line transmitting the optical signal is switched either from the main transmission line to the backup transmission line or from the backup transmission line to the main transmission line, either between the optical transmission equipment concerned and a neighboring upstream optical transmission equipment, or between other two optical transmission equipment sets located on an upstream side.

In a single-wavelength optical transmission system transmitting data with single wavelength light, there has been put into actual use a system having duplicated (redundant) transmission lines, i.e. the main transmission line and the backup transmission line, for a station apparatus of a single (non-duplicated) configuration, thereby providing fault tolerance ability to the transmission line. Provision of fault tolerance ability with multiple configuration for each station apparatus may be considered, but this is not adopted practically because cost increases.
FIG. 18 is a block diagram illustrating an overview of the single-wavelength optical transmission system having duplicated transmission lines. In this single-wavelength optical transmission system, terminal stations 101, 103, and a relay station 102 are provided as station apparatuses. In some cases, more than two relay stations, instead of one, may be configured in the system.
The transmission lines provided between the neighboring station apparatuses are duplicated. Between each station apparatus, main transmission lines F01, F02, R01 and R02 and backup transmission lines F11, F12, R11 and R12, which are made of light fiber, are provided. The main transmission lines are used normally, while the backup transmission lines are used when a failure (for example, fiber break and deterioration, etc. caused by secular change, etc.) occurs on the main transmission line.
Each station apparatus includes optical amplifiers (AMP. For example, Erbium-doped fiber amplifiers: EDFA) 201–206, so as to amplify input optical signals. Further, each station apparatus includes optical switches (OSW) 301–308 for transmitting input optical signals to either the main transmission line or the backup transmission line. The optical switches also receive the optical signals from either the main transmission line or the backup transmission line. Since a section between the stations is termed as span, in some cases, optical switches 301–308 may be termed as span switches.
These optical switches are switched to the main transmission line side when there is no failure (normal state). In the event that a failure occurs in the main transmission line, the corresponding optical switches are switched over to the backup transmission line side. For example, in the normal state, optical switch 301 is in the state switched to the main transmission line F01 side, and thereby an optical signal input from optical amplifier 201 is output to the main transmission line F01 side. In the event that a failure occurs in the main transmission line F01, optical switch 301 is switched over to the backup transmission line F11 side, and the optical signal from optical amplifier 201 is output to the backup transmission line F11.
Meanwhile, as a communication system enabling high-speed transmission of a large amount of data, a wavelength division multiplex (WDM) optical communication system has received wide attention. This WDM optical communication system multiplexes optical signals into different wavelength signals, which transmits on one optical fiber.
In such a WDM optical communication system, implementation of a fault tolerant system is also desired. Similar to the single-wavelength optical communication system shown in FIG. 18, a system has been put into practical use, such that optical fiber transmission lines between the station apparatuses have duplicated (redundant) configurations, consisting of the main transmission line and the backup transmission line, in contrast to the station apparatuses having single (non-duplicated) configurations, and that these transmission lines are switched by the optical switches.
However, most of the conventional WDM optical communication systems have the same number of optical switches as the number of multiplexed wavelengths, and each optical switch switches the optical signal on a wavelength-by-wavelength basis. Accordingly, in the conventional WDM optical communication system, with the increase of the number of the multiplexed wavelengths (for example, 160 waves, 320 waves, etc.), the cost has become increased because the provision of the optical switches with the same number as the number of the wavelengths is necessary.
Accordingly, there has been desired the WDM optical communication system in which the WDM multiplexed optical signals are switched collectively by a single optical switch.
However, in order to put into actual use such a WDM optical communication system using an optical switch for collectively switching optical signals, there are some problems to be solved, differently from the optical communication system using the conventional optical switch switching the optical signals on a wavelength-by-wavelength basis.
The first problem is how to compensate a transmission loss difference caused by the transmission line (optical switch) switchover.
When the transmission line is switched over from the main transmission line to the backup transmission line as a result of the switchover of the optical switch, an attenuation factor (loss) of the transmission line is varied, producing a varied signal level to be input to an optical amplifier in the succeeding stage. When the input signal level is varied, the level of amplified spontaneous emission (ASE) light (noise component) generated from the optical amplifier also varies. This produces an undesirable increase of possibility that the further succeeding optical amplifier becomes unable to amplify the signal component (communication signal component) included in the input signal to a predetermined level.
In order to solve such a problem, conventionally, variable optical attenuators have been provided on both, or either of, the main transmission line and the backup transmission line. By adjusting the attenuation factor of any variable optical attenuator, the optical signal level input from the main transmission line to the optical amplifier can be set substantially equal to the optical signal level input from the backup transmission line to the optical amplifier.
This method, however, has limit to cope with a variety of network structures. For example, this method is not applicable when the lengths of the main transmission line and the backup transmission line largely differ, resulting in that the difference of the attenuation factors between both transmission lines exceeds beyond an adjustable range of the variable optical attenuator. For this reason, it becomes necessary to introduce another method, so that each optical amplifier can amplify each signal component to a predetermined level without adjusting the attenuation factor.
The second problem is how to prevent a receiving quality deterioration of the optical signal caused by the transmission line (optical switch) switchover.
In some cases, an aspect of tilt produced in the optical signal is varied when a wavelength dependent loss (WDL) of the transmission line or the flatness in the gain of the intervened optical amplifier is varied after the switchover of the transmission line from the main transmission line to the backup transmission line, or vice versa, by use of the optical switches. This may produce an error in a particular wavelength signal at a receiving end, because of non-uniformity of the signal quality being produced among the respective wavelengths.
To cope with this problem, it is necessary to prevent the signal quality of each wavelength from deterioration even when the switchover is performed, by compensating the difference in the tilt.
The third problem is how to prevent generation of a light surge.
The light surge is generated by a burst emission of the energy accumulated in the optical amplifier (such as EDFA) during a light interception period of no optical signal input into the optical amplifier, when the optical signal input is resumed after the light interception.
In the WDM optical communication system, the light interception is produced when an optical signal is intercepted in the optical switch during the switchover time (for example, ten and a few milliseconds), and accordingly no optical signal is input to the amplifier. Also, the light surge is generated when the optical signal is input again to the optical amplifier through the optical switch, after the switchover completion of the optical switch.
Especially in the WDM optical communication system, since the optical signals are multiplexed, output power (output electric power and output level) from the optical amplifier becomes larger, in proportion as the increased number of wavelengths. Because the light surge is superposed onto this output level, the resultant output level becomes remarkably high, which may cause damage, such as melting of the optical fiber transmission line.
To prevent generation of such a light surge, one method may be considered so as to adjust the light interception period to a time sufficient for emitting the residual energy accumulated in the optical amplifier. However, this method is not preferable because a longer signal interception period than a tolerable time is produced by the switchover of the optical switch longer.
Accordingly, a method for preventing generation of the light surge, enabling the light interception period within the tolerable signal interception period, is required.


A process for preparing images on a tonable, light-sensitive layer using a transfer layer containing at least 20 percent by weight of a toner and a polymer with a maximum tensile strength of at least 2 N/mm.sup.2 as a binder. The pigmented transfer layers can be used in color proofing processes requiring high resolution, reproducible color density and low dot gain.

The reprographic industry uses light-sensitive recording materials wherein differences in the tackiness of the exposed and unexposed areas are utilized for image production. For example, German Patents 12 10 321, 19 04 058, 19 04 059 and 20 04 214, disclose a reproduction process in which a tacky photopolymerizable recording material, consisting of a support and a photopolymerizable layer containing at least one addition-polymerizable monomer and a photopolymerization initiator, is hardened by imagewise exposure, whereby the exposed image areas lose their tackiness. The latent image is then visualized by applying a suitable toner, which adheres only to the unexposed tacky areas. Excess toner remaining on the exposed, non-tacky image areas is removed. This process produces positive, and optionally colored, images of the original, and these images resemble in appearance images produced by the use of printing inks. Thus, the process has achieved considerable practical importance, particularly in the printing industry for proofing color separations.
German Patent 29 49 462 discloses pigmented layers containing 75 to 95 parts by weight pigment and 5 to 25 parts by weight of an elastomeric binder with a maximum tensile strength of less than 1.38 N/mm.sup.2 and an elongation at break of at least 50%. The process produces high opacity images that are used preferably for the reproduction of text and display pieces. However, due to the high opacity, the process is not suitable for color proofing processes. A reduction of pigment content does lead to a lower density, but it also causes a complete loss of resolution.
German Patent 12 85 876 describes photopolymerizable recording materials for thermal image transfer. Between the photopolymerizable layer and the support sheet, these recording materials have a layer of a thermoplastic polymer, such as, for example, polyethylene or ethylene/vinyl acetate copolymers combined with a wax, and optionally containing a pigment. The unexposed areas of the photopolymerizable layer with adhering portions of the intermediate layer can be transferred thermally. The portions of the intermediate layer corresponding to the unexposed areas adhere only partially to the photopolymerizable layer in this transfer, and the portions remaining on the support can be used for additional transfers. After multiple transfers, a transparent negative remains on the support. Only a portion of the intermediate layer is transferred each time, therefore, variations in the color density of the transferred areas are unavoidable.
Halftone color separations are used in reprography as copy originals for the preparation of offset or relief printing plates. The color separations are checked, prior to exposing the plates, with the aid of color proofing processes to determine whether the ultimate printing result will represent a tonally correct reproduction of the original. General standard specifications indicate that a resolution of 2%-98% dots at a screen spacing of 60 lines/cm is required for high quality offset printing. However, it is particularly difficult to achieve satisfactory resolution of pointy 2% dots in the highlights and of 98% dots in the shadows. It is also of considerable importance for halftone dots of the same size to be sharply defined and uniform over the entire surface, if good tonal value reproduction is to be achieved.
With the advancing technical development of printing machines that can now achieve a resolution of 1% to 99% dots, requirements for the proofing processes also become more stringent. Modern printing machines also achieve even smaller dot gain, which the proofing process must reflect.
Thus, the transfer layer such as the one described in German Patent 36 25 014, which uses a special binder system of incompatible polymers, cannot achieve the lower dot gain obtained by modern printing machines even though a resolution of 2% to 98% dots can be attained. In addition, the process for preparing the transfer materials described in German Patent 36 25 014 has several disadvantages. It is (1) time consuming and costly; (2) a controllable layer structure is quite difficult to achieve; (3) the pigments must be milled separately, (4) the production formulations must be processed immediately, and (5) the dispersions must be intensively mixed during the entire preparation process to prevent the components from settling and clumping. Only then can a uniform coating on the support be assured. The coating rate must also be low, a further disadvantage in the production process.
Accordingly, the object of the present invention is to provide a process for preparing images on tonable, light-sensitive layers by using a transfer layer containing at least one toner. A further object is to provide a process that achieves a high resolution of 1% to 99% dots as required by the printing industry. In addition, this process should provide highly uniform halftone values over the entire surface and very low dot gain, thus avoiding the previously described disadvantages and deficiencies. The process should also be useful for various tonable, light sensitive layers.

Process for preparation of images on tonable light-sensitive layers


The present invention provides a load bag and carrier board design that will allow the user to load film in a darkroom load magazine in room light. This is accomplished by tearing the bag open along the perforations and pulling off the outer bag. The bag and film are loaded into the magazine; as the access door is closed, the outer bag is pulled off. A label is placed at the bottom panel of the outer bag to identify package orientation and alert the user when the end of the bag is reached. At this point the package allows film to be loaded in room light conditions with a high risk of light fog on the edge (1/8") of the film. The fog is concentrated on the top edge of the film closest to the cassette door. With the addition of the cassette cover, the end user can load film in white light with no fog concerns.

Currently, laser imagers have darkroom load magazines available to load film. Such systems require that the user load the magazine with film in a darkroom. The user takes the empty magazine, into the darkroom, loads the film into the magazine and returns back to the imager. With this invention the magazine would be loaded at the imager in room light. From the foregoing discussion it is apparent that there remains a need within the art for a film load bag that can be used with film magazines in room light.

Room light load film magazine bag and cover loading system


The subject invention discloses a process for producing a neutralized latex that is useful in the manufacture of water reducible coatings which involves.. (1) free radical aqueous emulsion polymerizing at a pH of less then about 3.5, a monomer mixture which comprises based on 100 weight percent monomers: (a) from about 45 to about 85 weight percent vinyl aromatic monomers, (b) from about 15 to about 50 weight percent of at least one alkyl acrylate monomer, and (c) from about 1 to about 6 weight percent of at least one unsaturated carbonyl compound; in the presence of about 0.5 to 4.0 phm at least one phosphate ester surfactant; in the presence of about 0.5 to 4.0 phm of at least one water insoluble nonionic surface active agent to produce a latex; and in the presence of at least one seed polymer which contains repeat units which are derived from about 45 to about 85 weight percent vinyl aromatic monomers, from about 15 to about 50 weight percent alkyl acrylate monomers, and from about 1 to about 6 weight percent unsaturated carbonyl compounds; and PA0 (2) neutralizing the latex with ammonia to a pH which is within the range of about 7 to about 10.5 to produce the neutralized latex.

Most conventional coating resins are insoluble in water. Therefore, in general practice they have been dissolved in a suitable organic solvent or dispersed in water with the aid of an emulsifying agent or surfactant in order to provide a coating composition suitable for application to a substrate surface. A serious disadvantage of organic solvent solutions is that they are potentially toxic, flammable, and environmental pollutants.
Water reducible coatings do not present these problems and are, therefore, highly desirable. For this reason various water reducible coating resins, such as the one described in U.S. Pat. No. 4,474,926, have been developed. Water reducible coatings which utilize such resins have been developed for a variety of purposes and have been widely accepted in many applications such as highway striping paint.
There is a need for a coating for metal substrates which provide improved corrosion and rust resistance. Such coatings could be, for example, beneficially utilized in the automotive industry. It would be particularly desirable for such coatings to be of the water reducible type.
For purposes of this patent application, an aqueous coating system is considered to be a colloidal dispersion of a resin in water which can be reduced by the addition of water and which forms a durable coating when applied to a substrate surface. The term aqueous coating system is used herein interchangeably with the term water reducible coating. Other names which are sometimes applied to water reducible coatings are water born, water solubilized, and water dilutable.
U.S. Pat. No. 4,968,741, discloses a process for producing a neutralized latex that is useful in the manufacture of water reducible coatings which comprises:
(1) free radical aqueous emulsion polymerizing at a pH of less than about 3.5 a monomer mixture which comprises, based on 100 weight percent monomers: (a) from about 45 to about 85 weight percent vinyl aromatic monomers, (b) from about 15 to about 50 weight percent of at least one alkyl acrylate monomer, and (c) from about 1 to about 6 weight percent of at least one unsaturated carbonyl compound; in the presence of about 0.5 to 4.0 phm at least one phosphate ester surfactant and in the presence of about 0.5 to 4.0 phm of at least one water insoluble nonionic surface active agent to produce a latex; and
(2) neutralizing the latex with ammonia to a pH which is within the range of about 7 to about 10.5 to produce the neutralized latex.
The latices made utilizing the technique of U.S. Pat. No. 4,968,741, are outstanding for utilization in the formulation of coatings having improved moisture vapor transmission resistance and water spotting resistance. When applied to metal substrates, coating formulations made with such latices provide excellent corrosion and rust resistance. The latices described in U.S. Pat. No. 4,968,741, have proven to be extremely difficult to synthesize in large scale commercial operations. Attempts to synthesize such latices in large polymerization vessels, such as 500 gallon reactors, has resulted in severe coagulum formation.


This invention provides a method for forming polysilicon by using silane with introducing hydrogen, such that polysilicon is microcrystalline. This microcrystal polysilicon can be applied to floating gate of flash memory to improve the character of flash memory.

1. Field of the Invention
The present invention relates generally to flash memory and in particular the present invention relates to using microcrystalline polysilicon film as a floating gate to improving the performance of memory cell.
2. Description of the Prior Art
A typical flash memory comprises a memory array, which includes a large number of memory cells arranged in row and column fashion. Each of the memory cells includes a floating gate field-effect transistor capable of holding a charge. The cells are usually grouped into blocks. Each of the cells within a block can be electrically programmed in a random basis by charging the floating gate. The charge can be removed from the floating gate by a block erase operation. The presence or absence of the charge in the floating gate determines the data in a cell.
FIG. 1 is a cross-sectional view of a typical memory cell 5, such as a used in a flash memory. Memory cell 5 comprises a region of a source 60 and a region of a drain 70. Source 60 and drain 70 are separated by a predetermined space of a channel 80 region. Memory cell 5 further includes a floating gate 30 formed by a first polysilicon layer, and a control gate 50 formed by a second polysilicon layer. Floating gate 30 is isolated from control gate 50 by an interpoly dielectric layer 40 and from channel region 80 by a thin oxide layer (tunnel oxide layer) 20 approximately 100 angstroms thick.
FIG. 2 shows a magnified cross-section of a floating gate by using a polysilicon layer 84 formed on substrate 82 such as a tunnel oxide. Polysilicon layer 84 is formed by depositing silicon onto the surface of substrate 82 in a low pressure chemical vapor deposition (LPCVD) chamber at a temperature of approximately 600° C. by using silane (SiH4) chemistry. The grain size of polysilicon is about 1000 angstrom and about 2000 angstrom. The surface roughness of polysilicon layer 84 is a result of the large-grained columnar crystal structures within the film. This pronounced surface roughness makes it difficult to obtain good patterning profiles due to the significant variation in inter granular thickness of photoresist formed on the surface of the polysilicon layer 84, and the non-uniformity in reflectivity which occurs during the photolithographic patterning process. The non-uniformity in reflectivity of photoresist layer is forms bad etching profiles and makes it easy to obtain the poly stringer issue.
FIG. 3 shows a magnified cross-section of another floating gate by using a polysilicon layer 88 formed on substrate 86 such as a tunnel oxide. Polysilicon layer 88 is formed by a process in which silicon is deposited on the surface of a substrate in a LPCVD chamber at a temperature of approximately 550° C. By depositing silicon at this lower temperature, amorphous silicon is created because crystal grains cannot develop at this low temperature. This amorphous silicon is subsequently recrystallized by exposing the material to a temperature in excess of 600° C. The result is the polycrystalline structure shown in FIG. 3, wherein large crystal grains are formed. While the polysilicon layer 88 of FIG. 3 overcomes the problems associated with surface roughness described above of FIG. 2. The large grain size of polysilicon layer 88 reduces the grain boundary density of the film. In addition, because the polysilicon layer 88 is deposited at a low temperature, the deposition rate is similarly low, resulting in slow throughput times.
The storage or erase of the flash memory cell as shown in FIG. 1 is programmed by Fowler-Nordheim tunneling of electrons through a thin tunnel oxide layer between the floating gate and the channel. The thin tunneling oxide generally is about 100 angstroms. In the programming mode for flash memory, hot carriers tunnel from the channel to the floating gate and are stored in the floating gate. The control gate, the select gate and the drain of the flash memory cell are positively biased while the source is grounded. In erase mode, usually programmed, the drain is biased at high voltage to finish the erase process.
An over erased memory cell has a faster erase speed, which means a higher electron current through the tunneling oxide. When using large grain polysilicon floating gate to cause wider threshold voltage (Vt) distribution. If over erased blocks exist, threshold voltage distribution after erase has tail components and larger variance value. In other words, the wider erase threshold voltage distribution corresponds to large polysilicon grains.
In conventional to flash memory process, by using large grain polysilicon film as a floating gate. There are many drawbacks such as over erasing, wider threshold voltage distribution, tail bit issue, tunnel oxide quality down, higher polysilicon resistance and bed etching profile due to poly stringer issue.

Method for improving the performance of flash memory by using microcrystalline silicon film as a floating gate


An animation timeline is analyzed to determine one or more discrete states. Each discrete state includes one or more animation effects. The discrete states represent scenes of a slide in a slide presentation. The concepts of scenes allows user to view a timeline of scenes, open a scene, and direct manipulate objects in the scene to author animations. The animations can include motion path animation effects, which can be directly manipulated utilizing a motion path tweening method. To aid in direct manipulation of a motion path of an object, a ghost version of the object can be shown to communicate to a user the position of the object after a motion path animation effect that includes the motion path is performed. The ghost version may also be used to show a start position when a start point is manipulated.

Presentation application programs, such as MICROSOFT POWERPOINT, available from Microsoft of Redmond, Wash., allow users to create individual pages or "slides" for presentation in the form of a slide show. Each slide may contain text, graphics, sound, videos, and other objects. Animations may be applied to certain objects in a slide, such as text and graphics, to enhance the slide show.
Currently, MICROSOFT POWERPOINT's animation user interface ("UI") requires users to select an object, apply an animation primitive, and then adjust settings through a series of drop-down menus, spinners, and dialogs. Animation triggers include "On click", in which an animation effect is applied upon the click of the slide; "With previous", in which an animation effect is played at the same time as the previous item in the animation list or on load of the slide if the effect is first in the animation list; and "After previous", in which an animation effect is played immediately following the previous item in the animation list. Navigating the current MICROSOFT POWERPOINT user interface may be cumbersome to use for some users, and may prevent others from taking advantage of the animation features included in the program.
One particular type of animation effect is a motion path animation effect. When a user wants to animate an object utilizing a motion path animation effect, the user must provide an initial state for the object, a final state for the object, and define a type of path along which the object will move when the motion path animation effect is executed. The type of motion path may be a pre-defined motion path or a custom motion path. If the motion path is a straight line, the initial state or the end state can be easily adjusted by simply redrawing the line in between the two states. If the motion path is curved, however, then additional logic that is needed to properly scale the motion path to maintain the motion path itself. Moreover, when manipulating a motion path, it is helpful to know the end state of the motion path animation effect to allow for confident re-positioning of the end state.
It is with respect to these and other considerations that the disclosure made herein is presented.

Animation creation and management in presentation application programs


A method and apparatus for assembling a power semiconductor is provided. A device includes a printed circuit board, a heat sink, and a semiconductor chip package. The semiconductor chip package is located between the printed circuit board and the heat sink. A heat-generating surface of the semiconductor chip package is oriented such that the heat-generating surface faces the heat sink.

In the assembly of semiconductor chip packages, it is desirable to produce the semiconductor chip packages in a way that meets individual needs of consumers. Industrial consumers have a desire to efficiently attach semiconductor packages to boards like printed circuit boards (PCB).
In a semiconductor chip package, the semiconductor chip is embedded or housed within the chip package and the contact pads of the semiconductor chip are connected to external contact elements of the chip package. It is desirable to produce semiconductor chip packages so that their external contact elements allow a higher degree of flexibility with regard to the attachment of the semiconductor chip package to a board. It is also desirable to increase the modular applicability of the semiconductor chip package and, in particular, the possibility to connect further devices to the semiconductor chip package.
Semiconductor chip packages may be used in a variety of applications. These applications may include power applications implemented by chip-based power semiconductor elements such as power transistors, power diodes, and other elements. Such applications may be employed in diverse equipment such as power supplies for personal computer components, electronic lighting equipment, battery-based equipment, and many other types of equipment. With the use of these power elements, it may be desirable to connect the semiconductor chip packages to a thermally conductive device such as a heat sink. If the heat sink does not dissipate heat in a desired manner, components connected to the semiconductor chip packages or the semiconductor chip itself may be damaged.
Further, some currently used methods of assembling semiconductor chip packages, such as power modules that reduce heat dissipation, are expensive and may increase the complexity of the fabrication process. Consequently, there is a general need for cost-efficient solutions in assembling power semiconductor packages such that both the temperature and the temperature gradient of the fabricated package are minimized.


The invention relates to a cargo support device in a vehicle, which device is provided in a load floor of a load compartment. The cargo support device comprises a frame, which is foldable between a horizontal rest position, and an operative position, angled in relation to the load floor. The load floor is provided with a recess wherein the frame is arranged in the rest position. The frame is provided with an arm, foldable to an angled position in relation to the frame, in the operative position.

Vehicle interiors are configured with a cargo or load compartment. The load compartment is a relatively large free space without any separating devices. This implies that when smaller loads, such as grocery bags and small parcels, are to be transported, these tend to slide around in the load compartment during driving, and the contents of the bags tend to fall out and roll around in the load cargo or storage compartment, since the bags are not fastened. Thus, objects that fly around in the cargo or load compartment can also cause damage to details in the compartment or damage the interior of the cargo or luggage compartment.
Prior art cargo support devices have been proposed to address this problem. One of the cargo support devices of today arranged in a load compartment of a vehicle comprises a load floor with a door that can be raised around a transverse axis of the vehicle. The door extends substantially across the whole width of the load floor. Underneath the load floor there is provided one or more immersions, where the cargo can be placed during driving. The transverse axis is provided in the vicinity of the rear seat rest of the vehicle to uncover as big of an area as possible where the cargo can be placed. During driving, the cargo is kept in place with a resilient string that extends over and around the cargo or the cargo is hung up on hooks, provided on an underside of the door. After the transport of the cargo, the cargo is unloaded, whereafter the door is returned to its original position to form a conventional load floor of the load compartment.
The cargo or load compartments of vehicles of today usually contain varying loose objects or different accessories such as transport cages for pets, protective mats which cover the whole cargo or storage compartment, etc. To be able to use the above described cargo support device the cargo or storage compartment has to be totally emptied and thus the objects or the accessories have to be removed before the cargo support device can be used. This is thus not especially practical for the user.
It is therefore desirable to provide an improved cargo support device, which can be used even when the load compartment contains objects or accessories, and which, when not in use, can easily be folded and stored in the vehicle.
It is further desirable to provide a cargo support device that provides sufficient support for the loads during driving, such that they remain in a predetermined space during transport.


A system and method for detecting the position of the head and/or eye of a driver of an automobile and automatically adjusting the position of the steering wheel based on the head and/or eye position in order to provide the driver with an optimized view of the instrumentation panel and road. The system and method utilizes the vehicle parameters, driver parameters, and various settings to determine the proper position of the steering wheel including the height, proximity to driver, and tilt angle of the steering wheel. The system may also adjust the height and/or length of the steering column in order to adjust and provide the proper position of the steering wheel.

Automobiles are typically equipped with a steering mechanism that allows a driver to control the path of travel of the automobile. Modern steering mechanisms most commonly include a steering wheel, a steering column, and a steering arrangement, e.g., a rack and pinion arrangement, in mechanical communication with at least the front automobile wheels. The steering wheel is typically connected to an end of the steering column such that it rests proximate the automobile driver so that the driver can conveniently and comfortable reach and turn the steering wheel while seated.
In use, as illustrated in FIG. 1, the steering wheel 10 commonly rests between the automobile driver (not shown) and an instrumentation panel 20 located on the automobile dashboard 30. The instrumentation panel 20 typically includes gauges, meters, and/or system controls 25 which inform the driver of the status of several functions related to the automobile. The instrumentation panel 20 is preferably located such that it can be clearly viewed by the driver while driving the automobile without requiring the driver to change his or her position or posture. However, because the steering wheel 10 typically rests between the driver and the instrumentation panel 20 the view of the instrumentation panel 20 is often obscured by the steering wheel 10. Further, the position of the steering wheel 10 should also preferably not obscure the view of the road, so the driver has a substantially clear, unobstructed view of the road.
It is well-known to provide automobiles with adjustable tilt steering wheels, adjustable steering columns, and telescoping steering columns to allow automobile drivers to move the steering wheel to a comfortable and convenient position. Adjustable tilt steering wheels allow the position of the steering wheel to be moved to one of multiple positions by pivoting about a horizontal axis at the end of the steering column. Adjustable steering columns allow the position of the steering column to be raised and lowered to change the vertical position of the steering wheel. Telescoping steering columns allow the length of the steering column to be adjusted to change the proximity of the steering wheel to the driver.
Further, it is well-known to provide automobiles with convenience settings that allow the driver to store a preferred position for the steering wheel to a vehicle memory. These settings allow the driver to automatically recall and adjust the position of the steering wheel such as, for example, upon a manual activation of the setting or upon startup of the automobile.
While the known systems are useful, there remains a need for a system and method that automatically adjust the position of the steering wheel, such as tilt position, based on the position of the head and/or eyes of the driver. There also remains a need for a system and method that provides enhanced safety by maximizing driver visibility of the instrumentation panel and the road. Therefore, it is desirable to provide a system and method for automatically adjusting the position and/or tilt of the steering wheel based on the position of the head and/or eyes of the driver.

System and method for automatically adjusting a steering tilt position


An exercise ball device for exercising by a user while in a prone position. The exercise ball device includes a semi-circular shaped housing having an outer curved surface and an interior curved compartment having an inner curved surface. The housing has a retaining member positioned on the perimeter edge of the housing. The exercise ball device also includes a rolling ball positioned within the interior curved compartment, and the rolling ball is removably restrained within the interior curved compartment by the retaining member. Further, the outer curved surface of the housing has a restraint member attached thereto for receiving the hand of a user. Additionally, the rolling ball is approximately the same size as the interior curved compartment so that the rolling ball rotates or rolls within and relative to the housing.

Exercise ball devices where a user applies his or her own weight and strength for exercising are well-known in the art having many variations. These types of ball devices are used mainly for the development of the user's torso, stomach and the like. Other types of ball devices are used as balancing exercise devices, wherein the board rests on or against the ball and the person then positions a body part on the board. Many of these aforementioned exercise ball devices are not easy to use and do not provide good exercise results.
There remains a need for a new and improved exercise ball device that is simple to operate and exercise with when the user is in a bent over prone position. Additionally, the exercise ball device is uncomplicated in structure and easily used and operated by the user during his or her workout.


A ternary CAM system includes a main memory cell configured to store complementary data signals D/D#. A first transistor has a source coupled to receive data signal D#, and a gate coupled to receive a compare signal C. A second transistor has a source coupled to receive data signal D, and a gate coupled to receive complementary compare signal C#. A third transistor has a gate coupled to drain regions of the first and second transistors. A mask cell storing a mask value is coupled to the source of the third transistor. A pre-charged match line is coupled to the drain of the third transistor. If compare signals C/C# match data signals D/D#, then the third transistor is turned off, thereby isolating match line and mask cell. If compare signals C/C# don""t match data signals D/D#, then the third transistor is turned on, thereby coupling mask cell and match line.

The present invention relates to ternary content addressable memory (CAM) cells. More specifically, the present invention relates to ternary CAM cells having improved compare and mask circuits.
FIG. 1 is a circuit diagram of a conventional ternary CAM cell system 100, which includes main memory cell 101, compare circuit 102, mask circuit 103, pre-charge circuit 104, mask memory cell 105 and match line 106. Compare circuit 102 includes n-channel transistors 111-113, and mask circuit 103 includes n-channel transistor 114. A data value comprised of complementary data signals D and D# is written to main memory cell 101 on complementary bit lines BL and BL#, respectively. Once written, main memory cell 101 provides complementary data signals D# and D to the gates of transistors 111 and 112, respectively. A mask value (M) is written to mask memory cell 105. The mask value is applied to the gate of n-channel transistor 114 of mask circuit 103.
A compare operation is performed in ternary CAM cell system 100 as follows. Pre-charge circuit 104 applies a positive voltage to match line 106, thereby charging match line 106 to a logic high state. Pre-charge circuit 104 then allows match line 106 to float. A sense amplifier (not shown) senses the state of match line 106. A compare value comprised of complementary data signals C and C# is applied to complementary compare lines CMP and CMP#, respectively, and thereby to the sources of transistors 111 and 112, respectively. If the compare value matches the data value previously written to main memory cell 101, then a logic low signal is applied to the gate of transistor 113. In this case, transistor 113 is turned off, and match line 106 remains at a logic high state, thereby indicating a match condition.
However, if the compare value does not match the data value previously written to main memory cell 101, then a logic high signal is applied to the gate of transistor 113. In this case, transistor 113 is turned on. If transistor 114 is also turned on (i.e., the mask value M is programmed to a logic high value), then match line 106 is pulled down to a logic low state (i.e., ground), thereby indicating a no-match condition.
If the mask value M has a logic low value, then transistor 114 is turned off, and match line 106 will not be pulled down by ternary CAM system 100 regardless of the presence of a match or no-match condition.
Ternary CAM system 100 has the following shortcomings. First, ternary CAM system 100 requires two separate functional blocks to implement the compare and mask functions (i.e., compare circuit 102 and mask circuit 103). As a result, a relatively large number of transistors are required to implement ternary CAM system 100. Second, match line 106 is limited to a logic high pre-charge state.
FIG. 2 is a circuit diagram of another conventional ternary CAM system 200, which includes main memory cell 201, compare circuit 202, mask circuit 203, pre-charge circuit 204, mask memory cell 205 and match line 206. Compare circuit 202 includes n-channel transistors 211-212, and mask circuit 203 includes n-channel transistor 214. A data value comprised of complementary data signals D and D# is written to main memory cell 201 on complementary bit lines BL and BL#, respectively. Once written, main memory cell 201 provides complementary data signals D and D# to the sources of transistors 211 and 212, respectively. A mask value (M) is written to mask memory cell 205. The mask value is applied to the gate of n-channel transistor 214 of mask circuit 203.
A compare operation is performed in ternary CAM cell system 200 as follows. Pre-charge circuit 204 applies a positive voltage to match line 206, thereby charging match line 206 to a logic high state. Pre-charge circuit 204 then allows match line 206 to float. A sense amplifier (not shown) senses the state of match line 206. A compare value comprised of complementary data signals C and C# is applied to complementary compare lines CMP and CMP#, respectively, and thereby to the gates of transistors 211 and 212, respectively. If the compare value matches the data value previously written to main memory cell 201, then a logic high signal is applied to the source of transistor 214. If transistor 214 is turned on (i.e., the mask value M is programmed to a logic high value), a logic high signal is applied to match line 206, thereby indicating a match condition.
However, if the compare value does not match the data value previously written to main memory cell 201, then a logic low signal is applied to the source of transistor 214. If transistor 214 is turned on (i.e., the mask value M is programmed to a logic high value), a logic low signal is applied to match line 206, thereby indicating a no-match condition.
If the mask value M has a logic low value, then transistor 214 is turned off, and match line 206 will not be pulled down by ternary CAM-system 200 regardless of the presence of a match or no-match condition.
Ternary CAM system 200 has the following shortcomings. First, ternary CAM system 200 requires two separate functional blocks to implement the compare and mask functions (i.e., compare circuit 202 and mask circuit 203). Second, during a compare operation, the data value stored in main memory cell 201 can be disturbed by the current flow through compare circuit 202 and mask circuit 203.
It would therefore be desirable to have an improved ternary CAM system that overcomes the deficiencies of conventional ternary CAM systems.
Accordingly, the present invention provides a ternary CAM system that includes a main memory cell, a compare/mask circuit, a mask memory cell, a match line, a pre-charge circuit and a sense amplifier. The pre-charge circuit and the sense amplifier are coupled to the match line. The pre-charge circuit is programmable to pre-charge the match line to either a logic high state or a logic low state, depending on the configuration of the ternary CAM system. The main memory cell stores a data value represented by complementary data signals D and D#. The data signal D# is applied to the source of a first transistor of the compare/mask circuit, and the data signal D is applied to the source of a second transistor of the compare/mask circuit. The gate of the first transistor is coupled to receive a compare data signal C, and the gate of the second transistor is coupled to receive a compare data signal C#, wherein the compare data signals C and C# are complementary signals representing a compare value. The drains of the first and second transistors are coupled to the gate of a third transistor of the compare/mask circuit. The source of the third transistor is coupled to receive a mask value stored in the mask memory cell, and the drain of the third transistor is coupled to the pre-charged match line.
The compare data signals C and C# turn on one and only one of the first and second transistors. If the compare data value matches the data value, then the turned on one of the first and second transistors passes a signal having a first state to the gate of the third transistor, thereby turning off the third transistor. Thus, if the compare data value matches the data value, the match line remains isolated from mask memory cell. The pre-charged match line thereby remains in a pre-charged state.
If the compare data value does not match the data value, then the turned on one of the first and second transistors passes a signal having a second state to the gate of the third transistor, thereby turning on the third transistor. Thus, if the compare data value does not match the data value, the match line is coupled to the mask memory cell through the third transistor. The mask value stored in the mask memory cell may have a state that matches the pre-charged state of the match line, such that the mask memory cell implements a mask function. Alternately, the mask value may have a state that does not match the pre-charged state of the match line, such that the mask memory cell will change the state of the pre-charged match line when the compare data value does not match the data value.
In another embodiment, the compare/mask circuit is configured in a slightly different manner. In this embodiment, the data signal D# is applied to the gate of a first transistor of the compare/mask circuit, and the data signal D is applied to the gate of a second transistor of the compare/mask circuit. The source of the first transistor is coupled to receive a compare data signal C, and the source of the second transistor is coupled to receive a compare data signal C#, wherein the compare data signals C and C# are complementary signals representing a compare value. The drains of the first and second transistors are coupled to the gate of a third transistor of the compare/mask circuit. The source of the third transistor is coupled to receive a mask value stored in the mask memory cell, and the drain of the third transistor is coupled to the pre-charged match line.
The data signals D and D# turn on one and only one of the first and second transistors. If the compare data value matches the data value, then the turned on one of the first and second transistors passes a signal having a first state to the gate of the third transistor, thereby turning off the third transistor. Thus, if the compare data value matches the data value, the match line remains isolated from mask memory cell. The pre-charged match line thereby remains in a pre-charged state.
If the compare data value does not match the data value, then the turned on one of the first and second transistors passes a signal having a second state to the gate of the third transistor, thereby turning on the third transistor. Thus, if the compare data value does not match the data value, the match line is coupled to the mask memory cell through the third transistor. The mask value stored in the mask memory cell may have a state that matches the pre-charged state of the match line, such that the mask memory cell implements a mask function. Alternately, the mask value may have a state that does not match the pre-charged state of the match line, such that the mask memory cell will change the state of the pre-charged match line when the compare data value does not match the data value.
Advantageously, the compare/mask circuit only requires three transistors. Moreover, the compare/mask circuit does not draw a current that may disturb the data value stored in the main memory cell during a compare operation. In addition, the match line can be pre-charged to either a low state or a high state by controlling the pre-charge circuit, and programming the mask memory cell with the appropriate mask value.
In one embodiment, the data value is provided to the main memory cell on a first pair of bit lines, and the compare data value is provided to the compare/mask circuit on a second pair of bit lines. In one variation, the first and second pair of bit lines can be consolidated into a single pair of bit lines.
The present invention will be more fully understood in view of the following drawings and description.

Compact ternary content addressable memory cell


A speaker assembly includes a shellpot for receiving a speaker motor, the shellpot having a groove extending along an outer surface thereof. The speaker assembly further includes a speaker basket with a base portion having an opening therein for receiving the shellpot, the speaker basket including a plurality of flexible tabs substantially surrounding a perimeter of the opening, wherein the plurality of tabs are received in the groove to couple the shellpot to the speaker basket.

Plastic speaker baskets may be used to reduce weight and provide a low cost structure for certain speaker applications. Typically, plastic speaker baskets are molded directly over a metallic speaker shellpot, and then the rest of the speaker components are assembled in relation to the shellpot. However, the shellpot geometry often changes based on the design of the speaker assembly. Accordingly, new tooling, such as a new mold or mold detail, must be produced for each shellpot design, as well as each set of production tooling. As such, supporting multiple speaker designs can significantly increase manufacturing cost and complexity.
Some previous designs have accomplished attaching the shellpot to the plastic basket using either a twist lock design and/or using an adhesive to bond the shellpot to the plastic speaker basket. Although such designs allow the attachment of any of multiple shellpots to a common plastic basket, these designs may have insufficient durability for some applications. Further, a twisting or locking detail may lead to increased tooling complexity and manufacturing issues.


A low sidestream smoke cigarette comprises a conventional tobacco rod, and a combustible treatment paper having a sidestream smoke treatment composition. The treatment composition comprises in combination, an oxygen storage and donor metal oxide oxidation catalyst and an essentially non-combustible finely divided porous particulate adjunct for said catalyst.

Various attempts have been made to reduce or eliminate sidestream smoke emanating from a burning cigarette. The applicant developed various approaches to cigarette sidestream smoke control systems as described in its Canadian patents 2,054,735 and 2,057,962; U.S. Pat. Nos. 5,462,073 and 5,709,228 and published PCT applications WO 96/22031; WO 98/16125 and WO 99/53778.
Other sidestream smoke control systems have been developed which use filter material or adsorptive material in the tobacco, filter or paper wrapper. Examples of these systems are described in U.S. Pat. Nos. 2,755,207 and 4,225,636; EP patent application 0 740 907 and WO 99/53778. U.S. Pat. No. 2,755,207 describes a low sidestream smoke cigarette paper. The cigarette paper on burning yields a smoke substantially free of obnoxious components. The cigarette paper is cellulosic material in fibre form. It has intimately associated therewith a finely divided mineral type siliceous catalyst material. The cigarette paper which is essentially non-combustible and refractory remains substantially unchanged during combustion of the cigarette paper and functions like a catalyst in modifying the combustion of the paper. Suitable siliceous catalysts include acid-treated clays, heat-treated montmorillonite and natural and synthetic silicates containing some hydrogen atoms which are relatively mobile. Suitable mixed silica oxides include silica oxides with alumina, zirconia, titania, chromium oxide and magnesium oxide. Other silicas include the oxides of silicon and aluminum in a weight ratio of 9:1 of silica to alumina.
U.S. Pat. No. 4,225,636 describes the use of carbon in the cigarette paper to reduce organic vapour phase components and total particulate matter found in sidestream smoke. In addition, the carbon results in a substantial reduction in visible sidestream smoke emitting from a burning cigarette. Activated carbon is preferred as the carbon source. The use of the activated carbon results in a slight drop in visible sidestream smoke. Up to 50% of the cigarette paper may be finely divided carbon. The carbon-coated papers may be used as the inner wrap for the tobacco rod in combination with a conventional cigarette.
European patent application 0 740 907 published Nov. 6, 1996 describes the use of zeolites in the tobacco of the cigarette to alter the characteristics of the mainstream smoke and in particular remove various components from the mainstream smoke such as some of the tars. The zeolite as provided in the tobacco, also apparently change the characteristics of the sidestream smoke. The zeolites used were of a particle size between 0.5 mm to 1.2 mm.
Published PCT patent application WO 99/53778 describes a non-combustible sheet of treatment material for reducing sidestream smoke emissions. The sheet is used as a wrap and is applied over conventional cigarette paper of a conventional cigarette. The wrap has a very high porosity to allow the cigarette to burn at or close to conventional free-burn rates while at the same time reduce visible sidestream smoke emissions. The non-combustible wrap includes non-combustible ceramic fibres, non-combustible activated carbon fibres as well as other standard materials used in making the wrap. The wrap also includes zeolites or other similar sorptive materials and an oxygen donor/oxygen storage metal oxide oxidation catalyst. The non-combustible wrap provides an acceptable degree of sidestream smoke control, however, due to the non-combustible nature of the wrap, a charred tube remains.
U.S. Pat. Nos. 4,433,697 and 4,915,117 describe the incorporation of ceramic fibres in a cigarette paper manufacture. U.S. Pat. No. 4,433,697 describes at least 1% by weight of certain ceramic fibres in the paper furnish in combination with magnesium oxide and/or magnesium hydroxide fillers to reduce visible sidestream smoke emanating from the burning cigarette. The furnish of fibre pulp, ceramic fibres and fillers are used to make a paper sheet on conventional paper making machines. The ceramic fibres may be selected from the group of polycrystalline alumina, aluminum-silicate and amorphous alumina. A filler of magnesium hydroxide or magnesium oxide is used and is coated on or applied to the fibres of the sheet.
Ito, U.S. Pat. No. 4,915,117 describes a non-combustible sheet for holding tobacco. The thin sheet is formed from ceramic materials which upon burning produces no smoke. The ceramic sheet comprises a woven or non-woven fabric of ceramic fibre or a mixture of paper and ceramics thermally decomposed at high temperature. The ceramic fibre may be selected from inorganic fibres such as silica fibre, silica-alumina fibre, alumina fibre, zirconia fibre, or alumino borosilicate and glass fibre. The ceramic sheet is formed by binding these materials by inorganic binders such as silica gel or alumina gel. The fibres are a preferably 1 to 10 micrometers in diameter.
Sol gels have been applied to conventional cigarette paper in order to reduce sidestream smoke, particularly sol gels made from a magnesium aluminate, calcium aluminate, titania, zirconia and aluminum oxide, as described in Canadian Patent 1,180,968 and Canadian Patent application 2,010,575. Canadian Patent 1,180,968 describes the application of magnesium hydroxide in the form of an amorphous gel as a cigarette paper filler component to improve ash appearance and sidestream smoke reduction. The magnesium hydroxide gel is coated on or applied to the fibres of the sheet of the cigarette paper. Canadian patent application 2,010,575 describes the use of gels produced by a solution gelation or sol-gel process for controlling the combustion of wrappers for smoking articles. The gels may be applied as coatings to paper fibres before the paper is formed into wrappers. The wrappers are useful for reducing visible sidestream smoke. The metal oxides for the sol gels may be aluminum, titanium, zirconium, sodium, potassium or calcium.
Catalysts have also been directly applied to cigarette paper, such as described in Canadian Patent 604,895 and U.S. Pat. No. 5,386,838. Canadian Patent 604,895 describes the use of platinum, osmium, iridium, palladium, rhodium and rhuthenium in the cigarette paper. These metals function as oxidation catalysts to treat vapours arising from combustion of the paper wrapper. Optimum catalytic effect has been provided by the metal palladium. The metal particles in a suitable medium are dispersed onto the face of a paper wrapper before it is applied to the cigarette.
U.S. Pat. No. 5,386,838 describes the use of a sol solution comprising a mixture of iron and magnesium as a smoke suppressive composition. The smoke suppressive composition is made by co-precipitating iron and magnesium from an aqueous solution in the presence of a base. The iron magnesium composition demonstrates high surface area of approximately 100 m2/g to approximately 225 m2/g when heated to a temperature between 100° C. and approximately 500° C. The iron magnesium composition may be added to paper pulp which is used to make smoke suppressive cigarette paper. The iron magnesium composition apparently functions as an oxidation catalyst and reduces the amount of smoke produced by the burning cigarette. The catalyst may also be applied to the tobacco, for example, as described in U.S. Pat. No. 4,248,251, palladium, either in metallic form or as a salt, may be applied to the tobacco. The presence of palladium in tobacco reduces the polycyclic aromatic hydrocarbons in the mainstream smoke. Palladium is used in combination with an inorganic salt or nitric or nitrous acid. Such nitrates include lithium, sodium, potassium, rubidium cesium, magnesium, calcium, strontium, lanthanum, cerium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, erbium, scandium, manganese, iron, rhodium, palladium, copper, zinc, aluminum, gallium, tin, bismuth, hydrates thereof and mixtures thereof Catalysts have also been used in tubes to reduce sidestream smoke such as described in published PCT application WO 98/16125.
Catalytic materials have been used in aerosol types of cigarettes which do not produce sidestream or mainstream smoke per se, but instead a flavoured aerosol. Examples of these aerosol cigarettes include those described in U.S. Pat. Nos. 5,040,551, 5,137,034 and 5,944,025, which use catalysts to provide the necessary heat generation to develop the aerosol. Such catalyst systems include oxides of cerium, palladium or platinum.
Although the prior art contemplates various sidestream smoke control systems, none of them have provided a system which effectively reduces sidestream smoke by simply incorporating active components in the combustible cigarette paper so that the cigarette burns like a normal cigarette without appreciably affecting cigarette taste. Accordingly, this invention provides a sidestream smoke control system which not only looks and tastes like a conventional cigarette but as well, in accordance with aspects thereof, ashes like a normal cigarette.

This patent is subject to a terminal disclaimer.

Low sidestream smoke cigarette with combustible paper


Fanned air generated by a fan to cool a motor is discharged from a housing through fanned air discharge ports toward an opening formed in a base. The fanned air discharged toward the opening is then introduced into a groove in fluid communication with the opening. The groove is formed in a bottom surface of the base and has an open side at a front side of the base. The fanned air is then discharged from the front side of the base, blowing off saw dust on a cutting object so as to prevent dust from accumulating on a marking line on the cutting object.

1. Field of the Invention
The present invention relates to a portable electric cutting machine, and more particularly to a portable electric cutting machine provided with an air-discharge mechanism for discharging air from a housing into a saw blade housing section of a saw cover.
2. Related Art
When cutting a cutting object, such as timber, by using a portable electric cutting machine (hereinafter referred to as "portable electric circular saw"), a marking line is drawn on the cutting object and then the object is cut along the marking line for the purpose of improving the cutting accuracy. More specifically, a guide piece for indicating the edge position of the saw blade is disposed at the front end of a base so that the guide piece locates on an imaginary line extended in a cutting direction from the saw blade. A user can cut the cutting object while directly confirming the positional relationship between the blade edge of the saw blade and the marking line on the cutting object. Alternatively, the user can cut the cutting object while indirectly confirming the positional relationship between the blade edge of the saw blade and the marking line by aligning the guide piece with the marking line.
However, when the bottom surface of the base slides on the cutting object, the marked line may be blurred or erased due to friction between the bottom surface of the base and the upper surface of the cutting objects, disabling the user to confirm the positional relationship between the blade edge and the marking line. Also, if ink of the marking line transfers onto the bottom surface when sliding, then the ink may get back to the cutting object so that the cutting object gets dirty.
Further, if a large volume of saw dust produced during the cutting operation piles on the cutting object, the marking line becomes invisible. In this case, the user can no longer confirm the positional relationship between the blade edge of the saw blade and the marking line, resulting in degradation of cutting accuracy and decreasing in cutting efficiency.
Saw dust accumulates on the cutting object when, for example, the saw dust produced in the cutting operation flies up and then falls down on the cutting object. Therefore, it is conceivable to use a dust collector for collecting saw dust generated during cutting operation, thereby preventing saw dust from flying up during the cutting operation. However, dust can be produced during, not only cutting operations, but also other operations using various other tools. In this case, even if such a dust collector is used during cutting operations, dust may accumulate on the cutting object to hide the marking line. In this case, a user needs to wipe off or blow off the dust on the cutting object before starting a cutting operation so that the user can see the marking line. This reduces the efficiency of the cutting operation. Also, the user needs to stop the cutting operation to remove saw dust which has been generated and piled on the cutting object during the cutting operation. This reduces both the cutting accuracy and the efficiency of the cutting operation.
Japanese Utility Model registration No. 2607480 discloses a conventional portable electric circular saw, which includes a saw blade, a motor that drives the saw blade, a housing that houses the motor, a saw cover attached to the housing, a base linked to the housing, and a fan. The saw cover has a saw blade housing section that houses the upper half of the outer periphery of the saw blade. The base has a bottom surface that slides on the cutting object. The fan is driven by the motor for generating an air current (hereinafter referred to as "fanned air") to cool the motor. A wall of the saw cover that is positioned between the fan and the saw blade housing section is formed with fanned air discharge ports for discharging the fanned air into the saw blade housing section. The fanned air discharge ports are defined by a plurality of division walls.
Each division wall has a surface extending in parallel with a rotary shaft of the fan and in a radial direction of the rotary shaft. Thus, as passing through the fanned air discharge ports, the fanned air is directed to flow in a direction parallel to the rotary shaft of the fan and then discharged into the saw blade housing section. The fanned air discharged into the saw blade housing section in this manner collides with the lateral surface of the saw blade housed in the saw blade housing section and the lateral surface of a safety cover, which is rotatably disposed so that the saw blade housing section can house the safety cover during cutting operations. Then, the fanned air diffuses along the lateral surfaces of the saw blade and the safety cover. The diffused fanned air is then discharged to the outside of the saw cover through either between the inner wall of the saw cover and the saw blade or between the inner wall of the saw cover and the safety cover. Since the fanned air collides with the lateral surfaces of the saw blade and the safety cover substantially at a right angle, the collided fanned air diffuses substantially uniformly across wide area of the surfaces. The fanned air may be discharged from the rear side of the saw cover in the cutting direction due to air current, which is produced by rotation of the saw blade in the saw blade housing section.
The fan is a centrifugal fan. Fanned air generated by the centrifugal fan flows outwardly in radial directions of the centrifugal fan, swirls along the inner wall of the housing, and then is discharged into the saw blade housing section through the fanned air discharge ports. The flow rate and the amount of the fanned air discharged through the fanned air discharge ports are higher in areas close to the rotary axis of the fan and lower in areas remote from the rotary axis with respect to the radial directions of the fan. This arises a problem of generation of noise in radially remote areas. This problem can be overcome by downsizing the fan or reducing the rotation speed of the fan. However, this results in reducing the flow rate of the fanned air, thereby degrading the cooling performance of the fan.
Japanese Utility Model Application-Publication No. SHO-55-154101 discloses a portable electric circular saw that includes a cylindrical guide pipe disposed at the outside of a saw cover along a housing. The guide pipe is in communication with fanned air discharge ports. Fanned air discharged from the fanned air discharge ports is guided through the guide pipe to the top surface of a cutting object and blows off saw dust from the cutting object. In this manner, the saw dust and other dust are prevented from accumulating on the cutting object.
However, the guide pipe becomes an obstacle when confirming the positional relationship between the marking line and the blade edge of the saw blade, reducing the visibility of the marking line. Additionally, the assembling efficiency falls and the cost rises because of the increased number of the components.
When the cutting operation is performed, for example, in a closed area with limited space or in a room with painted walls still wet, blowing the fanned air to disperse the saw dust may not be preferable.

Portable electric cutting device with blower mechanism


Mask shops typically use carbon to repair any clear defects identified on a mask, irrespective of the type of mask. However, carbon can have different characteristics than the original patterning material on the mask. Therefore, a mask that is repaired using carbon may not optically perform as if it were defect-free. An automated method of repairing a clear defect on an attenuated phase shifting mask (PSM) provides an optimized plug size/shape. In this method, a repair solution to the clear defect can be simulated, thereby allowing the repair decision for an attenuated PSM to be advantageously made at the same time that inspection is done and before actual repair. Simulation can include performing model-based OPC on the repair solution.

1. Field of the Invention
The present invention relates to a phase shifting mask (PSM) and in particular to a simulation based repair technique for clear defects on an attenuated PSM.
2. Discussion of the Related Art
Photolithography is a well-known process used in the semiconductor industry to form lines, contacts, and other known structures in integrated circuits (ICs). In conventional photolithography, a mask (or a reticle) having a pattern of transparent and opaque regions representing such structures in one IC layer is illuminated. For example, FIG. 1 illustrates a cross section of a binary mask 100 having a transparent substrate 101 and a plurality of opaque (e.g. chrome) regions 102 formed on transparent substrate 101. During an exposure operation, a radiation source 103 is directed at mask 100. The emanating light from mask 100 is then focused on a photoresist layer provided on a wafer. During a subsequent development process, portions of the photoresist layer are removed, wherein the portions are defined by the pattern. In this manner, the pattern of mask 100 can be transferred to or printed on the photoresist layer.
FIG. 2 illustrates an attenuated phase shifting mask (PSM) 200 that uses phase destructive interference of the waves of incident light to transfer its pattern. Generally, phase-shifting shifts the phase of a first region of incident light waves approximately 180 degrees relative to a second, adjacent region of incident light waves to create a sharply defined interface between the first and second regions. For example, PSM 200 includes clear regions 202 and attenuated phase shifting regions 201. The phase shift of light passing through an attenuated phase shifting region 201 relative to light passing through a clear region 202 is approximately 180 degrees. Clear regions 202 are transparent, i.e. regions having an optical intensity transmission coefficient T>0.9. In contrast, attenuated phase-shifting regions 201 are partially transparent, i.e. regions having a low optical intensity transmission coefficient 0.03<T<0.2.
Unfortunately, because of the difficulty in providing a perfect mask fabrication process, at least some defects can be found on most masks. In general, a defect on a mask is anything that is different from the design database and is deemed out of tolerance by an inspection tool or an inspection engineer. Common mask defects include, for example, an isolated opaque pinhole defect in a clear region, an isolated clear spot defect in an opaque/attenuated region, an edge intrusion defect in an opaque/attenuated region, an edge protrusion defect in a clear region, a geometry break defect in an opaque/attenuated region, and a geometry bridge defect in a clear region.
Repairing defects in the clear regions, i.e. removal of material from regions in which the material does not belong, can be easily and accurately performed on both the binary mask as well as the attenuated PSM with a focused laser beam.
FIG. 4A illustrates a conventional process 400 for repairing clear defects on a generic (e.g. a binary or an attenuated PSM) mask. In process 400, after writing the mask with the desired pattern, the mask can be inspected in step 401. The inspection can include scanning the surface of the mask with a high-resolution microscope and capturing images of the mask. Step 402 determines whether a clear defect is found. If so, then step 403 determines whether the printing of this clear defect is not out of tolerance. Note that the goal of inspection is to correctly identify a defect to avoid a failed wafer processing. However, not all mask defects are important with respect to the desired result, i.e. an accurate representation of the original design layout on the photoresist material or etched into silicon. Specifically, not all mask defects will "print." The printability of a defect is how a defect would impact the outcome of a given photolithography and/or etching process. If the printing is not out of tolerance, then the mask can be approved (called CD registration) in step 405.
However, if the printing of the clear defect is out of tolerance, then step 404 determines whether that clear defect can be repaired. Note that such a designation might be contingent on the amount that the defect is out of tolerance or number of clear defects found in close proximity to each other. For example, the more defects found adjacent the clear defect, the greater the probability that the mask cannot be repaired in a cost efficient manner. Specifically, if clear defects are close to each other, then the aerial images of the patterns are correlated when they are repaired. This correlation makes the repair process control more complex, thereby increasing the difficulty of repair. Moreover, if the total number of defects on the mask is more than a predetermined amount, then repair of the mask is also not cost effective. If the clear defect is not repairable, then the mask is disqualified in step 406.
If the clear defect is repairable, then material can be deposited in the area identified as the clear defect in step 407. For example, FIG. 4B illustrates one repair solution to attenuated PSM 300. Specifically, in repaired mask 410, clear defect 302 has been filled in using a "plug" 411. Note that the exterior edges of plug 411 are substantially collinear with the edges of line 301. After cleaning the mask in step 408, process 400 can return to step 402 to identify other clear defects, if present. Otherwise, process 400 can end.
Of importance, sputtering tools, which are used to repair clear defects on masks (i.e. adding of material to regions in which the material does belong), can easily and accurately deposit carbon, but not other materials. Thus, neither chrome, which is typically used to form opaque regions 102 in binary mask 100 (FIG. 1), nor molybdenum silicide, which is typically used to form attenuated phase shifting regions 201 in attenuated PSM 200, can be used to repair clear defects.
The use of carbon to repair a clear defect on a binary mask is satisfactory because the intensity transmission coefficient of the opaque (e.g. chrome) regions and of the deposited carbon is identical, i.e. T<0.01. Thus, the repair solution in the binary mask accurately emulates a defect-free clear region. However, the use of carbon to repair a clear defect on an attenuated PSM is sub-optimal because the intensity transmission coefficient of the attenuated regions is significantly higher than for the deposited carbon. For example, the intensity transmission coefficient of molybdenum silicide is approximately T=0.03-0.2. Thus, carbon would fail to provide the desired phase shift on the attenuated PSM.
Without the appropriate phase shift, the printing of a feature on a wafer using attenuated PSM 410 may be out of tolerance. For example, FIG. 5 illustrates an aerial image 500 of a wafer printed using attenuated PSM 410. Note that printed line 501, which corresponds to attenuated line 301 and carbon plug 411 (see FIG. 4B), has not accurately printed. Specifically, printed line 501 is thinner at location 502, which is the area associated with carbon plug 411.
To address this problem, mask shops can collect experimental data on various plug shapes and sizes by exposing a test mask and then analyzing the resulting printed features on the developed wafer. This experimental data can be expanded to include multiple test masks exposed under various stepper scanner conditions, which can significantly impact the printability of such features on the wafer. These conditions can include: wavelength, numerical aperture, coherence factor, illumination mode, exposure time, and exposure focus/defocus among others. Unfortunately, the collection of this experimental data requires the use of expensive mask writing and exposure tools, valuable blank wafers (which could otherwise be used for integrated circuits), as well as the time-consuming analysis of a skilled engineer, thereby rendering an empirical approach impractical for commercial mask production.
Therefore, when asked to propose a repair solution for a clear defect on an attenuating PSM, an engineer may attempt to compensate for the lack of phase effect by arbitrarily increasing the plug size a predetermined amount for all clear defects on the mask. For example, FIG. 6 illustrates another repair solution to attenuated PSM 300. Specifically, repaired mask 600 includes a carbon plug 601 that is significantly larger than plug 411 (FIG. 4B). However, without the benefit of empirical data, the engineer cannot know whether the size and/or shape of plug 601 will result in a printed feature within tolerance. This uncertainty has contributed to the reluctance of many mask shops to use attenuated PSM technology, despite the fact that an attenuated PSM can provide more smaller, more sharply defined features than a binary mask.
Therefore, a need arises for an automated technique to provide accurate repairs to clear defects on an attenuated PSM.

Simulation based PSM clear defect repair method and system


A thin film device includes a metal sulfide layer formed on a single crystal silicon substrate by epitaxial growth; and a compound thin film with ionic bonding, which is formed on the metal sulfide layer by epitaxial growth. Alternatively, a thin film device includes a metal sulfide layer formed on a single crystal silicon substrate by epitaxial growth; and at least two compound thin films with ionic bonding, which are formed on the metal sulfide layer by epitaxial growth. For example, (11 20) surface AlN/MnS/Si (100) thin films formed by successively stacking a MnS layer (about 50 nm thick) and an AlN layer (about 1000 nm thick) on a single crystal Si (100) substrate, are used as a substrate, and a (11 20) surface GaN layer (about 100 nm thick) operating as a light emitting layer is formed on the substrate, thereby fabricating a thin film device.

1. Field of the Invention
The present invention relates to a thin film device including a compound having ionic bonding (called "ionic crystal" from now on) and its fabrication method, and more particularly to a thin film device and its fabrication method preferably applicable to electronic devices utilizing an ionic crystal thin film as a functional film, such as a high brightness blue light emitting device (semiconductor laser), metal insulator semiconductor field effect transistor (MISFET), high electron mobility transistor (HEMT) and thin film capacitor.
2. Description of the Related Art
Nitride, oxide and sulfide each exhibit a variety of physical properties. Although they are valuable functional materials as polycrystalline, their single crystals can become more effective or exhibit new characteristics. When applying these materials to thin film devices, forming their single crystal thin films can implement high performance, high function devices unachievable by polycrystalline thin films.
For example, consider devices using nitride thin films such as a high brightness blue light emitting device using GaN thin films, a MISFET using AlN/GaN thin films and a HEMT using AlGaN/GaN thin films. Although a variety of such devices have been proposed and implemented, unless the nitride thin films consist of single crystal thin films without little lattice defects or grain boundary, their carrier mobility can be reduced, or the light emitting efficiency of their light emitting layers or their lifetime can be reduced.
As for the single crystal thin films, it is common that they are epitaxially grown using a single crystal substrate. For example, there have been reported that GaN-based single crystal thin films are formed on a single crystal sapphire substrate by an MOCVD (Metal Organic Chemical Vapor Deposition) method or by a gas source MBE method (Molecular Beam Epitaxial Method), or on a SiC substrate by a low pressure metal organic vapor phase epitaxy (see, Kiyoteru Yoshida "Electronic devices using GaN" pp. 787–792 and Kuramata et al., "Continuous-Wave Operation InGaN Laser Diodes On SiC Substrates," pp. 797–800, OYOBUTURI Vol. 68, No. 7, published by The Japan Society of Applied Physics, Jul. 10, 1999). As for the oxide-based single crystal thin films, their epitaxial thin films are formed on a substrate composed of single crystal strontium titanate (SrTiO3:STO), single crystal lanthanum aluminate (LaAlO3:LAO) or single crystal sapphire substrate by a sputtering or PLD method (Pulsed Laser Deposition).
However, since the sapphire substrate, SiC substrate, single crystal STO substrate and single crystal LAO substrate are expensive, it is preferable that the thin films be formed on a general purpose Si substrate. In addition, from the viewpoint of a merger with Si devices, it is preferable that the functional thin films be epitaxially grown on a Si substrate. However, it is difficult to epitaxially grow an ionic bonding thin film directly on a Si single crystal substrate. The reason for this is considered that since the silicon is a covalent crystal, a material with a lattice constant differ from that of Si by a few percent cannot grow coherently (pseudomorphically) on a substrate, thereby leaving lattice defects.
As a method of forming a thin film on a Si single crystal substrate, a method of inserting a buffer layer is known.
A commonly used method is to form a metal oxide of CeO2, Y2O3, ZrO2 and the like, which are more susceptible to oxidation than Si, thereby preventing non-crystalline (amorphous) SiO2 from being generated. However, it is unavoidable that the Si surface undergoes oxidation, which offers a problem of degrading the film characteristic of the buffer layer formed on the SiO2. In addition, a buffer layer using TiN or TaN also has a problem of forming SiNx.
To cope with this, a method using a metal sulfide thin film as the buffer layer is proposed (see, Japanese Patent Application Laid-open No.2002-003297). According to the relevant document, the formation Gibbs' energy of forming the Si sulfide is rather small. Thus, when its lattice constant is close to that of Si, it is possible to epitaxially grow the sulfide without forming an amorphous layer on an interface between the buffer layer and Si. The Japanese Patent Application Laid-open No.2002-003297 discloses that the elements such as Al, Ba, Be, Ca, Ce, In, La, Li, Mg, Mn, Mo, Na, Sr, Ta and Zr have the formation Gibbs' energy greater than Si in forming the sulfide, and that using a sulfide composed of one of them or a combination of them can suppress the Si interface reaction, and proposes an oxide thin film device and its fabrication method using the metal sulfide layer as the buffer layer.
Furthermore, CdS and ZnS also have the formation Gibbs' energy greater than that of Si in forming the sulfide.
However, a thin film device including epitaxial thin films for a laser diode or LED formed on a Si substrate, and its fabrication method have not been implemented.

Thin film device and its fabrication method


An illuminated surgical retractor for defining and illuminating a subcutaneous surgical field in the space near a vessel (such as the saphenous vein or radial artery) during a procedure for harvesting the vessel, wherein the illuminated surgical retractor includes a handle member pivotally connected at an acute angle to a first elongate section that has an at least partially tapered width, and includes a second elongate section releasably connected to the first elongate section, wherein a portion of the second elongate section defines an illumination input end portion, which is optically coupled to a light source to substantially illuminate the second elongate section, and further including an insertion area positioned on the proximal end portion of the first elongate section to allow the second elongate section to be inserted into the first elongate section.

1. Field of the Invention
The present invention relates to medical devices, and, in particular, to a retractor for harvesting a blood vessel, which, in turn, is used in connection with an ongoing or subsequent surgical procedure. More particularly, the present invention provides such a retractor that is capable of defining and illuminating a subcutaneous working space to ameliorate accessibility to, and to facilitate visualization and harvesting of one or more blood vessels (e.g., saphenous vein) for grafting/transplantation in connection with a surgical procedure (e.g., coronary bypass surgery).
2. Description of Related Art
In certain surgical procedures, it is necessary to remove a portion (or even the entirety) of a patient's blood vessel for use in another, often remotely located part of that, or a different patient's body. For example, it is known to remove/excise some or all of a patient's saphenous vein, cephalic vein, basilic vein, radial artery, or mammary artery for transplantation in connection with a coronary bypass surgical procedure. Once transplanted, the removed section (or entirety) of the vein/artery functions as a graft that replaces both the coronary arteries, which, as a result of aging and/or disease, have become blocked by plaque deposits, stenosis, or cholesterol, thus severely inhibiting their ability to supply life-sustaining blood to the patient's heart.
In some instances, these blockages can be treated with angioplasty, atherectomy or stent placement, and, therefore, coronary bypass surgery is not warranted. Quite often, however, a coronary bypass is required because these treatment methods are either contraindicated, or have proven incapable of removing such blockages from coronary arteries.
According to current coronary bypass surgery techniques, a blood vessel is harvested from elsewhere within a patient's body and grafted into a locus between the patient's aorta and the coronary artery beyond the point of blockage. It is preferred to use a blood vessel taken from the patient undergoing bypass surgery, since he/she is a ready source of suitable vessels that will not be rejected by his/her own body after transplantation.
Currently, the saphenous vein (which is located in a patient's leg) is the most commonly used graft/substitute for small arteries such as the coronary arteries. This is likely because the saphenous vein is typically 3 to 5 mm in diameter (i.e., about the same size as the coronary arteries), and further, because the venous system of the leg is sufficiently redundant, such that following removal of the saphenous vein, other veins that remain within the patient's leg are adequate to provide return blood flow.
Harvesting the saphenous vein entails making one or more incisions in a patient's leg, then using a retractor to reach beneath and lift the skin to expose underlying subcutaneous/connective tissue. This tissue is then pulled away to reveal the saphenous vein, which is then carefully removed.
Although handling of the saphenous vein should be kept to a minimum, it must be separated from the connective tissue, and that requires some contact with the vein. Thus, after the saphenous vein is exposed, medical personnel grasps it with their fingers while stripping off the surrounding tissues with dissecting scissors or other scraping instruments. The medical personnel then uses their fingers and/or blunt dissection tools to separate the vein from the surrounding tissue.
Once the saphenous vein has been completely separated from the surrounding tissue and the tributary veins that feed into the saphenous vein, medical personnel cut the proximal and distal end portions of the vein, and remove the vein from the leg. The saphenous vein is then prepared for implantation into the graft site, and the incision(s) made in the patient's leg is/are closed (e.g., by suturing or with staples).
Until recently, only one incision was made to access the saphenous vein. This incision was quite long—spanning a patient's groin to at least their knee, and often to their ankle.
Making this long, "filet-like" incision inherently presents a serious risk of injury to the medial lymph bundle and/or to nerves located within the patient's leg, as well as a realistic risk of infection to the incision site. Moreover, the healing process associated with this "filet-like" incision is quite protracted (often more prolonged than the healing time associated with the incision(s) made in the patient's chest in furtherance of the coronary bypass) and very painful, especially if the patient has circulation problems in their extremities. Ultimately, in fact, the incision often does not heal properly, and, in such instances, requires medical attention and/or an invasive procedure (e.g., corrective surgery) to enable proper healing thereof.
As indicated in U.S. Pat. No. 6,193,651 to DeFonzo, U.S. Pat. No. 6,228,025 to Hipps et al, and U.S. Pat. No. 6,322,499 to Evans et al., however, techniques now exist that allow the saphenous vein to be harvested by making several small (i.e., about 2.5 inches to 4 inches in length) transverse incisions on the proximal thigh, at the level of the knee joint, and, optionally, at the inner malleolus.
In accordance with these techniques, a retractor is inserted into each of these incisions to define, access and illuminate subcutaneous space. The retractor is used to form a skin bridge to allow for retraction of at least some of the fat and tissue surrounding the saphenous vein, which is then harvested according to, for example, the technique described above, but without the risks/drawbacks associated with making a "filet-like" incision.
Although such risks/drawbacks are avoided by making comparatively smaller incisions in connection with saphenous vein harvesting procedures, some in the art believe that other drawbacks—ones that were not prevalent when saphenous vein harvesting was performed by making the long, "filet-like" incision—can arise by virtue of making these small incisions and/or due to the design of the retractors used in connection with such procedures.
For example, some believe the harvesting process has become complicated by the need to utilize equipment that is small enough to fit into both these small incisions and the subcutaneous space. In particular, they believe that vessel harvesting equipment (e.g., a retractor) should have certain dimensions in order to easily and confidently manipulate a patient's skin and tissue, but also that it is currently not possible for the equipment to have such dimensions, and yet still be able to fit within these small incisions and the subcutaneous space.
One group of patients that would appear to be most affected by these alleged equipment-related limitations are obese patients. Because obese patients tend to have increased quantities of subcutaneous fat and/or tissue in their legs, it is perceived that equipment that is able to fit within small incisions cannot manipulate such fat and tissue to an extent that allows for proper visualization of the subcutaneous space.
Thus, the procedure for harvesting a saphenous vein from obese patients potentially creates a tradeoff that, at least in the minds of some, renders the procedure contraindicated for such patients. This is troubling because it suggests that the obese (who, at present, represent a significant percentage of those who require coronary artery bypass surgery) may have fewer options for vessels that may be harvested for grafting in connection with a coronary artery bypass procedure.
Yet another perceived problem with current techniques for the harvesting of vessels (e.g., the saphenous vein) is that some believe the design of retractors used in connection with harvesting techniques may impede optimal visualization of at least some of the subcutaneous space.
As noted above, such retractors are designed to reach beneath and lift a patient's skin to expose underlying, connective tissue and, in doing so, to create subcutaneous space near the vessel to be harvested.
For example, in furtherance of usage of the retractor (see FIG. 1) described and depicted in U.S. Pat. No. 6,228,025 to Hipps et al. to harvest a patient's saphenous vein, the retractor 210 is grasped at its handle 220, and placed within an incision in a patient's leg in a direction such that the proximal end 211 of the retractor enters the incision (and leg) first, followed by the remainder of its blade sections 230, 240.
Thus, when the retractor 210 is properly positioned beneath a patient's skin, the proximal end 211 of the retractor is located farthest (as compared to the remainder of the blade) from the incision. Once the retractor 210 has been inserted as such, the handle 220 is arched/lifted to, in turn, lift the entire blade, thus defining the subcutaneous space.
As described in U.S. Pat. No. 6,228,025 to Hipps et al., use of the retractor 210 allows for the creation and visualization of enough subcutaneous space to quickly and reliably perform vessel harvesting. Because of the design of the retractor 210, however, the entirety of this subcutaneous space might not be able to be optimally visualized. Most notably, the subcutaneous space defined at or near the proximal end 211 of the retractor 210 may be especially difficult to visualize. This is because the overlying skin and tissue tends to collapse atop and "flap over" the proximal end 211 of the retractor, thus potentially preventing optimal visualization of the area, especially if the patient is obese and, as such, has increased quantities of underlying tissue and/or fat.
Therefore, a need exists for surgical equipment, particularly a retractor, that is able to fit within the small incisions that are made in a patient in connection with minimally invasive vessel harvesting (e.g., saphenous vein or radial artery) and within the subcutaneous space that is defined under the patient's skin, but that also can easily and effectively manipulate a patient's underlying fat and/or tissue (even if the patient has abnormally large quantities thereof, e.g., if the patient is obese) and that can allow for increased visualization of the subcutaneous space defined by the retractor.

Pivotal and illuminated saphenous vein retractor with tapered design