The invention relates to an apparatus for climbing an upright columnar member such as a tree, pole, or the like, using two climbing members. The first climbing member has a first upright member gripping structure and an adjustable platform spaced from the upright member to accommodate the body of the user in a sitting position. The adjustable platform is preferably a seat which is adjustable to permit the occupant to recline from an upright sitting position. The second climbing member has a second upright member to accommodate the feet of the user. One or both of the climbing members have a retraction device and locking mechanism for adjustably maintaining the climbing members in substantially horizontal position relative to the ground as the climber ascends or descends the tree.

1. Field of the Invention
The present invention relates to stands which grasp upright columnar members such as trees, poles or the like which permit the user to be securely positioned on the columnar member above the ground. More particularly, the invention relates to climbing stands formed of two climbing members which are alternately raised by the user to attain a desired elevation in a tree, or on a pole or the like. The present invention includes an upper climbing member having a seat which is adjustable to permit an occupant to sit in a reclining or lounging position. Both the upper climbing member and the lower climbing member permit automatic or self-adjustment of the spacing of the grasping members so as to readily effect adjustment of the angle of each climber relative to the upright columnar member.
2. Description of the Prior Art
A tree trunk is tapered and has a reduced diameter as elevation along the trunk is increased. To compensate for this, in conventional two-part climbing stands, it is important to set the initial spacing of the gripping portions of the tree climbing apparatus so as to initially engage both upper and lower frames with the outwardly extending ends oriented at a sufficient upward angle relative to the columnar member such that as the two parts are moved upward in step-wise or tandem alternating fashion, the angle attained at the desired elevation will result in the seat and footrest being substantially level or parallel to the ground. Alternatively, it may be desirable to have either or both frames oriented at a slight angle with the outward end cocked upward relative to the columnar member such that the user will tend to move or fall toward the columnar rather than away from it.
Tree climbing apparatus typically are used by hunters. The hunting environment is frequently characterized by climbing trees in dark, wet and cold conditions, in situations in which minimizing noise is desirable. Initial ascent of a tree is often accompanied by a feeling of excitement and anticipation. Similarly, descent of a tree after a "kill" can be under excited conditions. Alternatively, after a long day of waiting in the cold and wet, a tired, exasperated and hungry hunter must descend the tree. Human nature being what it is, if the initial angle is not chosen properly, and the angle at the desired elevation is thus tilted downward, users frequently tend not to lower the tree stand, reestablish a better starting angle, and start over. Hence, less than optimum angles frequently result with attendant hazards to the users. It is therefore desirable to be able to adjust the angle as the two parts are advanced up the tree. In addition, during periods between ascent and descent, a considerable amount of time may be spent seated while awaiting game to pass by. It is thus desirable for the hunter to be comfortable by having a seat which can recline from an upright position, with the hunter's feet extended outward.
Seating in a comfortable, properly aligned position is an important attribute to be attained by a tree climbing stand. The prior art has addressed this attribute in a somewhat scattered approach with no single tree climbing stand providing features addressed to both adjustable comfort in seating position and adjustable alignment of the tree climbing stand at any vertical position on a tree.
Two part tree stands for use in game hunting which permit upright seating with a separate footrest intended for comfort are known in the art. An example is a treestand sold under the PREDATOR trademark by API-Outdoors, Inc., Tallulah, La. Such seat has the drawback that it does not provide adjustment of the footrest or backrest to permit the user to lounge in the seat. Furthermore, such seat does not provide adjustment of the angle of the seat with respect to the horizontal to compensate for the narrowing of the tree trunk.
A two-part grasping-type tree climbing stand is disclosed in U.S. Pat. No. 4,331,216 to the present inventor, the teachings of which are hereby incorporated by reference. Such patent does not, however, provide for automatic or self-adjustment of the grasping members so that optimum angles of the climbers relative to the upright columnar member can be maintained throughout the ascent and/or descent.
Prior art which discloses attempts to provide adjustable tree climbing members include U.S. Pat. Nos. 4,997,063 and 4,995,475. Tree stands having spring biased locking pins are disclosed in U.S. Pat. Nos. 4,428,459 and 4,834,217. Tethering or connecting upper and lower platforms is shown in U.S. Pat. Nos. 4,549,633, 4.321,983 and 3,485,320.
However, none of these prior art tree climbers permit ready automatic or self-adjustment of the gripping or grasping members such that the optimum desired platform angle can be readily adjusted and maintained, especially taking into account the conditions under which such tree climbers are typically used. Furthermore, none of these prior art tree climbers permits the user to quickly or easily adjust the seat to varying reclining or "lounging" positions while seated in the device.

Automatically adjustable tree climbing stand having a lounging seat


An edge flap arrangement is provided for an aircraft wing and includes a main flap element and an actuator for moving the main flap element relative to the wing. A linkage arrangement supports the main flap element from the aircraft wing for movement relative to the wing, and includes including a drop hinge link arrangement having a fixed strut secured to the aircraft wing and a drop link secured to the main flap element. The fixed strut and drop link are pivotally connected by a hinge point having a bearing installed therein. The bearing includes an outer race, an inner race and an annular seal assembly snap-fit into the outer race. The annular seal assembly includes first and second annular retaining rings and a resilient ring disposed between the first and second annular retaining rings.

There are many types of bearings that are used in various applications. Such bearings include journal bearings, roller bearings, spherical bearings and hourglass type bearings. In general, these bearings have an inner race that is disposed at least partially in an outer race. The inner race and outer race are movable relative to one another. There is an annular cavity between the inner race and the outer race that typically contains a lubricant. One well known problem with bearings is the ingress of debris and contaminants into the annular cavity which can cause premature failure of the bearings due to degradation of the lubrication. Moreover, operation of the bearing can cause the lubricant to inadvertently escape from the annular cavity.
In an effort to mitigate the aforementioned problems, seals have been positioned across the annular cavity to maintain the lubricant in the cavity and to prevent the ingress of debris into the annular cavity. However, during operation, such seals become dislodged from the bearing and fail to function. In addition, such seals have often been too flexible, thereby allowing the seal to glide over debris and sweep the debris into the annular cavity.
Bearings are typically used in aircraft wing flap arrangements. For example, U.S. Pat. No. 8,714,493 describes a trailing edge flap arrangement for an aircraft wing that includes a drop linkage arrangement that includes one or more bearings. The subject matter of U.S. Pat. No. 8,714,493 is incorporated by reference herein, in its entirety. U.S. Pat. No. 8,714,493 is assigned to Airbus® Operations Limited, Bristol United Kingdom.
One of Airbus's® aircraft that employees the drop linkage arrangement is known as the Airbus® and A-350® aircraft. Airbus® and A-350® are a registered trademarks of Airbus Corporation, having numerous registered trademarks therefor. The Airbus® A-350® aircraft is defined by a wing planform—with a 64.7-meter wingspan, a total area of 442 square meters, and high swept leading edge. The Airbus® and A-350® aircraft includes a drop-hinge linkage mechanism to improve wing flap deployment kinetics, along with the introduction of a downwards movement for the upper wing spoilers to fill the gaps that occur when flaps are extended. In addition, the Airbus® and A-350® aircraft includes flight computer performs in-flight trimming of the inboard and outboard flaps, creating a variable camber wing that adapts to different flight conditions. In one embodiment, the Airbus® and A-350® aircraft employs 53 per cent of composites (i.e., Carbon Fiber Reinforced Plastic) in the fuselage and wing to reduce the need for fatigue-related inspections required on more traditional aluminum jetliners. The Airbus® and A-350® aircraft has a seating capacity between 280-440. The Airbus® and A-350® aircraft has two engines (e.g., two Rolls-Royce Trent XWB engines). The Airbus® and A-350® aircraft has a flying range of up to 7,950 nautical miles.

Composite annular seal assembly for bearings in aircraft


Disclosed herein is a golf ball having a scuff-resistant, soft cover formed from more than 90 wt. % of one or more acrylate ester-containing ionomeric resins. The acrylate ester-containing ionomeric resins preferably are terpolymers. The golf ball has good durability and a high spin rate. A method of making the golf ball also is disclosed.

The present invention relates to golf balls having ionomeric covers, and more particularly to golf balls having covers formed from acrylate ester-containing ionic copolymers.
Ionomeric resins are polymers containing interchain ionic bonding. As a result of their toughness, durability, and flight characteristics, various ionomeric resins sold by E. I. DuPont deNemours and Company under the trademark xe2x80x9cSurlyn(copyright)xe2x80x9d and by the Exxon Corporation (see U.S. Pat. No. 4,911,451) under the trademark xe2x80x9cEscor(copyright)xe2x80x9d and the tradename xe2x80x9clotekxe2x80x9d, have become the materials of choice for the construction of golf ball covers over the traditional xe2x80x9cbalataxe2x80x9d (trans polyisoprene, natural or synthetic) rubbers. The softer balata covers, although exhibiting enhanced playability properties, lack the durability necessary for repetitive play.
Ionomeric resins are ionic copolymers of an olefin such as ethylene and a metal salt of an unsaturated carboxylic acid, such as acrylic acid, methacrylic acid, or maleic acid. Metal ions, such as sodium or zinc, are used to neutralize some portion of the acidic groups in the copolymer resulting in a thermoplastic elastomer exhibiting enhanced properties, i.e. improved durability, etc., for golf ball cover construction over balata. However, the advantages gained in increased durability have been offset to some degree by the decreases produced in playability. This is because the durable ionomeric resins tend to be very hard when utilized for golf ball cover construction, and thus lack the degree of softness required to impart the spin necessary to control the ball in flight.
As a result, while there are currently more than fifty commercial grades of ionomers available from DuPont and Exxon with a wide range of properties which vary according to the type and amount of metal cations, molecular weight, composition of the base resin (i.e. relative content of ethylene and methacrylic and/or acrylic acid groups) and additive ingredients such as reinforcements, etc., a great deal of research continues in order to develop golf ball cover compositions exhibiting not only the improved impact resistance and carrying distance properties produced by the xe2x80x9chardxe2x80x9d ionomeric resins, but also the playability (i.e. xe2x80x9cspinxe2x80x9d) characteristics previously associated with the xe2x80x9csoftxe2x80x9d balata covers, properties which are still desired by the more skilled golfer.
In various attempts to produce a durable, high spin ionomeric golf ball, the golfing industry has blended the hard ionomeric resins with a number of softer ionomeric resins. U.S. Pat. Nos. 4,884,814 and 5,120,791 are directed to cover compositions containing blends of hard and soft ionomeric resins. The hard copolymers typically are made from an olefin and an unsaturated carboxylic acid. The soft copolymers are generally made from an olefin, an unsaturated carboxylic acid, and an acrylate ester. It has been found that golf ball covers formed from hard-soft ionomer blends tend to become scuffed more readily than covers made of hard ionomer alone. It would be useful to develop a golf ball having a combination of softness and durability which is better than the softness-durability combination of a golf ball cover made from a hard-soft ionomer blend.
An object of the invention is to provide a golf ball with a soft cover which has good scuff resistance.
Yet another object of the invention is to provide a golf ball having a favorable combination of spin rate and durability.
A further object of the invention is to provide a golf ball having a soft cover made from a cover material which is blended with minimal mixing difficulties.
Another object of the invention is to provide a method of making a golf ball which has a soft cover with good scuff resistance and cut resistance.
Yet another object of the invention is to provide a method of making a durable golf ball with a relatively high spin rate.
Other objects will be in part obvious and in part pointed out more in detail hereafter.
The invention in a preferred form is a golf ball comprising a core and a scuff-resistant cover. The cover comprises an ionomeric resin having more than 90 weight % of one or more acrylate ester-containing ionic copolymers. The one or more acrylate ester-containing ionic copolymers are each formed from (a) an olefin having 2 to 8 carbon atoms, (b) an unsaturated monomer of the acrylate ester class having from 1 to 21 carbon atoms, and (c) an acid which includes at least one member selected from the group consisting of xcex1, xcex2-ethylenically unsaturated mono- or dicarboxylic acids with a portion of the acid groups being neutralized with cations. The one or more acrylate ester-containing ionic copolymers have an overall Shore D hardness of 40-64. The resulting golf ball has a coefficient of restitution of at least 0.770.
The one or more acrylate ester-containing ionic copolymers preferably are terpolymers. In each copolymer, the olefin preferably is an alpha olefin, and the acid preferably is acrylic acid. The overall cover preferably has a Shore D hardness of no more than about 64, and more preferably about 40 to 64.
The one or more acrylate ester-containing ionic copolymers typically have a degree of neutralization of the acid-groups in the range of about 10-100%. In a preferred form of the invention, the covers have a scuff resistance rating of 3.0 or better when subjected to the Golf Ball Cover Scuff Test which is described below.
In a particularly preferred form of the invention, the cover comprises an ionomeric resin having at least 95 weight % of one or more acrylate ester-containing ionic copolymers. The cover preferably contains at least 90 weight % ionomeric resin. Each of the acrylate ester-containing copolymers preferably comprises ethylene, at least one acid selected from the group consisting of acrylic acid, maleic acid, fumaric acid, itaconic acid, methacrylic acid, and half-esters of maleic, fumaric and itaconic acids, and at least one comonomer selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, n-octyl, 2-ethylhexyl, and 2-methoxyethyl-1-acrylates.
Another preferred form of the invention is a method of making a golf ball. The method comprises the steps of obtaining a golf ball core and forming a scuff-resistant cover over the core. The cover comprises an ionomeric resin having more than 90 weight % of one or more acrylate ester-containing ionic copolymers formed from (a) an olefin having 2 to 8 carbon atoms, (b) an unsaturated monomer of the acrylate ester class having from 1 to 21 carbon atoms, and (c) an acid which is selected from the group consisting of alpha, beta-ethylenically unsaturated mono- or dicarboxylic acids with a portion of the acid groups being neutralized with cations. The one or more acrylate ester-containing ionic copolymers preferably have a Shore D hardness of about 40-64.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others and the article possessing the features, properties, and the relation of elements exemplified in the following detailed disclosure.
The present invention overcomes mixing difficulties associated with the preparation of soft-covered ionomeric golf balls by forming the cover of soft ionomeric golf balls from a cover composition in which the ionomer has more than 90 weight % of an acrylate ester-containing ionic copolymer or blend of acrylate ester-containing ionic copolymers. Furthermore, the invention provides golf ball covers having a favorable combination of durability and spin rate.
The one or more acrylate ester-containing ionic copolymers to be used in forming the cover of the inventive golf ball each contain an olefin, an acrylate ester, and an acid. In a blend of two or more acrylate ester-containing ionic copolymers, each copolymer may contain the same or a different olefin, acrylate ester and acid than are contained in the other copolymers. Preferably, the acrylate ester-containing ionic copolymer or copolymers are terpolymers, but additional monomers can be combined into the copolymers if the monomers do not substantially reduce the scuff resistance or other good playability properties of the cover.
For a given copolymer, the olefin is selected from the group consisting of olefins having 2 to 8 carbon atoms, including, as non-limiting examples, ethylene, propylene, butene-1, hexene-1 and the like. Preferably the olefin is ethylene.
The acrylate ester is an unsaturated monomer having from 1 to 21 carbon atoms which serves as a softening comonomer. The acrylate ester preferably is methyl, ethyl, n-propyl, n-butyl, n-octyl, 2-ethylhexyl, or 2-methoxyethyl 1-acrylate, and most preferably is methyl acrylate or n-butyl acrylate. Another suitable type of softening comonomer is an alkyl vinyl ether selected from the group consisting of n-butyl, n-hexyl, 2-ethylhexyl, and 2-methoxyethyl vinyl ethers.
The acid is a mono- or dicarboxylic acid and preferably is selected from the group consisting of methacrylic, acrylic, ethacrylic, xcex1-chloroacrylic, crotonic, maleic, fumaric, and itaconic acid, or the like, and half esters of maleic, fumaric and itaconic acid, or the like. The acid group of the copolymer is 10-100% neutralized with any suitable cation, for example, zinc, sodium, magnesium, lithium, potassium, calcium, manganese, nickel, chromium, tin, aluminum, or the like. It has been found that particularly good results are obtained when the neutralization level is about 50-100%.
The one or more acrylate ester-containing ionic copolymers each has an individual Shore D hardness of about 5-64. The overall Shore D hardness of the acrylate ester-containing ionic copolymer or blend of acrylate ester-containing ionic copolymers is 40-64. It is preferred that the overall Shore D hardness of the acrylate ester-containing ionic copolymer or blend is in the range of 50-64 in order to impart particularly good playability characteristics to the ball. It has been found that excellent results can be obtained when the Shore D hardness of the acrylate ester-containing ionic copolymer or acrylate ester-containing ionic copolymer blend is in the range of 52-54 for a soft covered golf ball or 62-64 for a somewhat harder ball.
The cover of the invention is formed over a core to result in a golf ball having a coefficient of restitution of at least 0.770, more preferably at least 0.780, and most preferably at least 0.790. The coefficient of restitution of the ball will depend upon the properties of both the core and the cover. The cover of the present invention is adapted for use with any type of golf ball core.
The acrylate ester-containing ionic copolymer or copolymers used in the golf ball of the invention can be obtained by neutralizing commercially available acrylate ester-containing acid copolymers such as polyethylene-methyl acrylate-acrylic acid terpolymers, including ESCOR ATX (Exxon Chemical Company) or poly (ethylene-butyl acrylate-methacrylic acid) terpolymers, including NUCREL (DuPont Chemical Company). Particularly preferred commercially available materials include ATX 320, ATX 325, ATX 310, ATX 350, and blends of these materials with NUCREL 010 and NUCREL 035. The acid groups of these materials and blends are neutralized with one or more of various cation salts including zinc, sodium, magnesium, lithium, potassium, calcium, manganese, nickel, etc. The degree of neutralization ranges from 10-100%. Generally, a higher degree of neutralization results in a harder and tougher cover material. The properties of non-limiting examples of commercially available un-neutralized acid terpolymers which can be used to form the golf ball covers of the invention are provided below in Table 1.
The ionomer resins used to form the golf balls of the invention are produced by reacting the acrylate ester-containing acid copolymer with various amounts of the metal cation salts at a temperature above the crystalline melting point of the copolymer, such as a temperature from about 200xc2x0 F. to about 500xc2x0 F., preferably from about 250xc2x0 F. to about 350xc2x0 F., under high shear conditions at a pressure of from about 100 psi to 10,000 psi. Other well known blending techniques may also be used. The amount of metal cation salt utilized to produce the neutralized ionic copolymers is the quantity which provides a sufficient amount of the metal cations to neutralize the desired percentage of the carboxylic acid groups in the high acid copolymer. When two or more different copolymers are to be used, the copolymers can be blended before or after neutralization. Generally, it is preferable to blend the copolymers before they are neutralized to provide for optimal mixing.
The compatibility of the acrylate ester-containing copolymers with each other in a copolymer blend produces a golf ball having a surprisingly good scuff resistance for a given cover hardness. The golf ball according to the invention has a scuff resistance of no higher than 3.0. It is preferred that the golf ball has a scuff resistance of no higher than about 2.5 to ensure that the golf ball is scuff resistant when used in conjunction with a variety of types of clubs, including sharp-grooved irons, which are particularly inclined to result in scuffing of golf ball covers. The best results according to the invention are obtained when the cover has a scuff resistance of no more than about 2.0. The scuff resistance test is described in detail below.
The golf ball of the invention has a spin rate of 7,500 or more. It is particularly preferred that the golf ball of the invention have a spin rate of 8,000 or more in order to provide experienced players with excellent spin characteristics. In a particularly preferred form of the invention, the golf ball has a spin rate of at least 8,500. These spin rates are surprisingly high given the good scuff and cut resistance ratings of the ionomeric cover material. The test for spin rate is described below.
Additional materials may also be added to the ionic cover compositions of the present invention as long as they do not substantially reduce the playability properties of the ball. Such materials include dyes (for example, Ultramarine Blue sold by Whitaker, Clark, and Daniels of South Plainsfield, N.J.) (see U.S. Pat. No. 4,679,795), pigments such as titanium dioxide, zinc oxide, barium sulfate and zinc sulfate; UV absorbers; antioxidants; antistatic agents; and stabilizers. Moreover, the cover compositions of the present invention may also contain softening agents such as those disclosed in U.S. Pat. Nos. 5,312,857 and 5,306,760, including plasticizers, metal stearates, processing acids, etc., and reinforcing materials such as glass fibers and inorganic fillers, as long as the desired properties produced by the golf ball covers of the invention are not impaired. Furthermore, non-ionomeric cover materials such as e.g., metallocene catalyzed polyolefins, including EXACT materials available from EXXON, can be blended with the terpolymers as long as a favorable combination of scuff resistance, COR, compression and spin rate is obtained.
When a blend of two or more acrylate ester-containing ionic copolymers is to be used, the cover compositions of the present invention may be produced according to conventional melt blending procedures. Generally, the copolymer resins are blended in a Banbury type mixer, two-roll mill, or extruder prior to neutralization. After blending, neutralization then occurs in the melt or molten state in the Banbury mixer. Mixing problems are minimal because preferably more than 91 wt %, and more preferably at least 95 wt % of the ionic copolymers in the mixture contain acrylate esters, and in this respect, most of the polymer chains in the mixture are similar to each other. The blended composition is then formed into slabs, pellets, etc., and maintained in such a state until molding is desired. If necessary, further additives such as inorganic fillers, antioxidants, stabilizers, processing aids, etc., may be added and uniformly mixed before initiation of the molding process. In one embodiment of the invention, a masterbatch of non-acrylate ester-containing ionomer with pigments and other additives incorporated therein is mixed with the acrylate ester-containing copolymers in a ratio of about 1-7 weight % masterbatch and 93-99 weight % acrylate ester-containing copolymer.
The golf balls of the present invention can be produced by molding processes which include but are not limited to those which are currently well known in the golf ball art. For example, the golf balls can be produced by injection molding or compression molding the novel cover compositions around a wound or solid molded core to produce a golf ball having a diameter of about 1.680-1.80 inches and typically but not necessarily weighing about 1.620 ounces. The standards for both the minimum diameter and maximum weight of the balls are established by the United States Golf Association (U.S.G.A.).
The cores of the inventive golf balls typically have a coefficient of restitution of about 0.775 and a PGA compression of about 110. The term xe2x80x9csolid coresxe2x80x9d as used herein refers not only to one piece cores but also to those cores having a separate solid layer beneath the cover and over the core. When the golf ball of the invention has a solid core, this core can be compression molded from a slug of uncured or lightly cured elastomer composition comprising a high cis content polybutadiene and a metal salt of an xcex1, xcex2, ethylenically unsaturated carboxylic acid such as zinc mono- or diacrylate or methacrylate. To achieve higher coefficients of restitution and/or to increase hardness in the core, the manufacturer may include a small amount of a metal oxide such as zinc oxide. In addition, larger amounts of metal oxide than are needed to achieve the desired coefficient may be included in order to increase the core weight so that the finished ball more closely approaches the U.S.G.A. upper weight limit of 1.620 ounces. Non-limiting examples of other materials which may be used in the core composition including compatible rubbers or ionomers, and low molecular weight fatty acids such as stearic acid. Free radical initiator catalysts such as peroxides are admixed with the core composition so that on the application of heat and pressure, a curing or cross-linking reaction takes place.
Wound cores are generally produced by winding a very large elastic thread around a solid or liquid filled balloon center. The elastic thread is wound around the center to produce a finished core of about 1.4 to 1.6 inches in diameter, generally. Since the core material is not an integral part of the present invention, a detailed discussion concerning the specific types of core materials which may be utilized with the cover compositions of the invention are not specifically set forth herein.
As indicated, the golf balls of the present invention may be produced by forming covers consisting of the above-described compositions around cores by molding processes. For example, in compression molding, the cover composition is formed via injection at e.g. about 380xc2x0 F. to about 450xc2x0 F. into smooth surfaced hemispherical shells which are then positioned around the core in a dimpled golf ball mold and subjected to compression molding at e.g. 200xc2x0-300xc2x0 F. for 2-10 minutes, followed by cooling at 50xc2x0-70xc2x0 F. for 2-10 minutes, to fuse the shells together to form an unitary ball. In one type of injection molding process, the cover composition is injected directly around the core placed in the center of a golf ball mold for a period of time at a mold temperature of from 50xc2x0 to about 100xc2x0 F. After molding, the golf balls produced may undergo various further processing steps such as buffing, painting, and marking.

Golf ball with ionomeric cover and method of making same


A slot antenna apparatus includes a grounding conductor having an outer edge including a first portion facing a radiation direction and a second portion other than the first portion, a one-end-open feed slot formed in the grounding conductor along the radiation direction such that an open end is provided at a center of the first portion, and a feed line including a strip conductor close to the grounding conductor and intersecting with the feed slot at at least a part thereof to feed a radio frequency signal to the feed slot. The slot antenna apparatus further comprises at least one one-end-open parasitic slot having an electrical length equivalent to one-quarter effective wavelength in a certain stop band, the parasitic slot having an open end at the second portion, and being formed in the grounding conductor so as not to intersect with the feed line.

1. Field of the Invention
The present invention relates to an antenna apparatus for transmitting and receiving analog radio frequency signals or digital signals in a microwave band, a millimeter-wave band, etc. More particularly, the present invention relates to a slot antenna apparatus operable in a wideband and having stop bands.
2. Description of the Related Art
A wireless device operable in a much wider band than that of prior art devices is required for the following two reasons. As the first reason, it is intended to implement a novel short-range wireless communication system with the authorization of use of a very wide frequency band, i.e., an ultra-wideband (UWB) wireless communication system. As the second reason, it is intended to utilize a variety of communication systems each using different frequencies, by means of one terminal.
For example, when converting a frequency band into a fractional bandwidth being normalized by a center frequency fc of an operating band, a frequency band from 3.1 GHz to 10.6 GHz authorized for UWB in U.S. corresponds to a value of 109.5%, indicating a very wide band. On the other hand, in cases of a patch antenna and a one-half effective wavelength slot antenna which are known as basic antennas, the operating bands converted to fractional bandwidths are less than 5% and less than 10%, respectively, and thus, such antennas cannot achieve a wideband property such as that of UWB. For example, referring to the frequency bands currently used for wireless communications in the world, a fractional bandwidth to the extent of 30% should be achieved in order to cover bands from the 1.8 GHz band to the 2.4 GHz band with one same antenna, and similarly, a fractional bandwidth to the extent of 90% should be achieved in order to simultaneously cover the 800 MHz band and the 2 GHz band with one same antenna. Furthermore, in order to simultaneously cover bands from the 800 MHz band to the 2.4 GHz band, a fractional bandwidth of 100% or more is required. The more the number of systems simultaneously handled by one same terminal increases, thus resulting in the extension of a frequency band to be covered, the more a wideband antenna with small size is required to be implemented.
A one-end-open one-quarter effective wavelength slot antenna is one of the most basic planar antennas, and a schematic view of this antenna is shown in FIGS. 31A, 31B, and 31C (hereinafter, referred to as a "first prior art example"). FIG. 31A is a schematic top view showing a structure of a typical one-quarter effective wavelength slot antenna (showing a grounding conductor 103 on a backside by phantom), FIG. 31B is a schematic cross-sectional view along the dashed line in FIG. 31A, and FIG. 31C is a schematic view showing a structure of the backside of the slot antenna in FIG. 31A by phantom. As shown in FIGS. 31A, 31B, and 31C, a feed line 113 is provided on a front-side of a dielectric substrate 101, and a notch with a width Ws and a length Ls is formed in a depth direction 109a from an outer edge 105a of an infinite grounding conductor 103 provided on a backside thereof. The notch operates as a slot resonator 111, one of its ends is opened at an open end 107. The slot 111 is a circuit element which is obtained by completely removing a conductor in thickness direction, in a partial region of the grounding conductor 103, and which resonates near a frequency fs at which one-quarter of the effective wavelength is equivalent to the slot length Ls. The feed line 113 formed in a width direction 109b intersects with the slot 111 at a portion thereof, and electromagnetically excites the slot 111. A connection to an external circuit is established through an input terminal. Note that according to common practice, a distance Lm of the feed line 113 from its open-ended termination point 119 to the slot 111 is set to the extent of one-quarter effective wavelength at the frequency fs, so as to achieve input impedance matching. Further, note that according to common practice, a line width W1 is designed based on a thickness H of the substrate and a permittivity of the substrate, such that the characteristic impedance of the feed line 113 is set to 50Ω.
As shown in FIGS. 32A, 32B, and 32C, Patent Document 1 discloses a structure for operating the one-quarter effective wavelength slot antenna shown in the first prior art example, at a plurality of resonant frequencies (hereinafter, referred to as a "second prior art example"). A slot 111 has a slot length Ls, and includes a capacitor 16 so as to connect points 16a and 16b each located a distance Ls2 away from an open end. When the antenna is excited at a plurality of resonant frequencies at a feeding point 15, the antenna operates with different slot lengths Ls and Ls2 as shown in FIGS. 32B and 32C, and thus the bandwidth can be extended. However, according to the frequency characteristics shown in Patent Document 1, it is not enough to obtain a currently required ultra-wideband characteristics.
Non-Patent Document 1 discloses a method of operating a slot resonator in a wideband, which is short-circuited at both ends of a slot, and is of a one-half effective wavelength slot antenna (hereinafter, referred to as the "third prior art example"). FIG. 33 is a schematic top view showing a structure of a slot antenna described in Non-Patent Document 1. In FIG. 33, a grounding conductor 103 and a slot 111 on a backside of a substrate are shown by phantom. The slot 111 is formed in the grounding conductor 103, such that the slot 111 has a certain width Ws, and a length Ls equivalent to one-half effective wavelength, and such that the slot 111 is coupled to a feed line 113 at a position 51a which is offset by a distance d from the center of the slot 111. According to prior art methods for matching input impedance of a slot antenna, a method has been used in which for exciting the slot 111, the feed line 113 intersects with the slot 111 at a position on the feed line 113 apart from an open-ended termination point 119 by one-quarter effective wavelength at a frequency fs. However, as shown in FIG. 33, in the third prior art example, a region extending over a distance Lind from the open-ended termination point 119 of the feed line 113 is replaced by an inductive region 121 which is a transmission line with a characteristic impedance higher than 50Ω, and that inductive region 121 is coupled to the slot 111 at substantially the center of the inductive region 121 (i.e., in FIG. 33, t1 and t2 are substantially equal to each other). In this case, a width W2 of the inductive region 121 is set to a certain width narrower than the width of the feed line 113, the length Lind of the inductive region 121 is set to one-quarter effective wavelength at a center frequency f0 of an operating band, and the inductive region 121 operates as a one-quarter wavelength resonator different from the slot resonator. As a result, an equivalent circuit structure includes two resonators, which is increased from one resonator that is included in a typical slot antenna, and a double-resonance operation is achieved by coupling the resonators resonating at frequencies close to each other. In an example shown in FIG. 2(b) of Non-Patent Document 1, a good reflection impedance characteristic of −10 dB or less is achieved at a fractional bandwidth of 32% (near 4.1 GHz to near 5.7 GHz). As shown in comparison of actual measurement results of reflection characteristics versus frequency in FIG. 4 of Non-Patent Document 1, the fractional bandwidth of the antenna of the third prior art example is much wider than a fractional bandwidth of 9% of a typical slot antenna fabricated under conditions using the same substrate.
Further, in Non-Patent Document 2 shown as a fourth prior art example, a printed monopole antenna as one type of monopole antennas, known by its wideband operation, is successfully operated with low reflection in the UWB band. However, as is clearly seen from an E-plane radiation pattern shown in FIG. 5(b) of Non-Patent Document 2, the main beam direction greatly changes depending on frequency. In addition, the half-width of the main beam in the E-plane also greatly varies depending on frequency.
In Patent Document 2 shown in FIG. 34 as a fifth prior art example, a printed monopole antenna itself is provided with a band-stop filter function. This aims to avoid interference between systems because, although a wide frequency band is assigned to a UWB system, existing wireless systems are already operating in parts of the band. Particularly, in Europe and Japan, it is unauthorized by regulation to output UWB signals in the 5 GHz band used for wireless LANs, and thus, it is necessary to deal with this regulation. On the other hand, since it is difficult to implement a ultra-wideband filter for a GHz band with small size, a band-stop function is required to be provided for an antenna itself. In the fifth prior art example, a radiation conductor 2 as a printed monopole is provided above a grounding conductor plate 1, and a ground feeding point 1f and a signal feeding point 2f are positioned, respectively, at a location where the grounding conductor plate 1 and the radiation conductor 2 are close to each other. In this case, one-end-open slot resonators NR and NL, each having a width Nh and a length Nd and having one-quarter effective wavelength in a stop band, are configured at an outer edge portion of the radiation conductor 2 as the printed monopole, thus achieving the band-stop function.
Prior art documents related to the present invention are as follows:
(1) Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-336328;
(2) Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-273638;
(3) Non-Patent Document 1: L. Zhu, et al., "A Novel Broadband Microstrip-Fed Wide Slot Antenna With Double Rejection Zeros", IEEE Antennas and Wireless Propagation Letters, Vol. 2, pp. 194-196, 2003; and
(4) Non-Patent Document 2: H. R. Chuang, et al., "A Printed UWB Triangular Monopole Antenna", Microwave Journal, Vol. 49, No. 1, January 2006.
As discussed above, sufficient wide band operation has not been achieved in the prior art slot antennas. Although the printed monopole antenna, which is expected as a wideband antenna for UWB, can operate with low reflection in an ultra-wideband and also achieves the band-stop function in parts of the band, it is difficult to maintain the main beam direction in an operating band. As a result, even when such an antenna is applied to a UWB system, it is difficult to cover a communication area.
First of all, in the case of a typical one-end-open slot antenna with only one resonator in its configuration as in the first prior art example, a frequency band, where a good reflection impedance characteristic can be achieved, is limited to a fractional bandwidth to the extent of a little less than 10%.
In the second prior art example, although a wideband operation is achieved by incorporating a capacitive reactance element into a slot, it can be readily noticed that additional components such as a chip capacitor are required, and the characteristics of the antenna vary depending on variations in characteristics of the newly incorporated additional components. Further, according to the examples disclosed in FIGS. 13 and 19 of Patent Document 1, it is difficult to achieve a characteristic of input impedance matching with low reflection in an ultra-wideband.
In the third prior art example, the fractional bandwidth characteristic is limited to the extent of 35%. Further, as compared to the antennas of the first and second prior art examples with one-end-open slot resonators which are of one-quarter effective wavelength resonators, it is disadvantageous in reducing size to use a slot resonator which is short-circuited at both ends and is of a one-half effective wavelength resonator.
In the fourth prior art example, although the low-reflection characteristic is achieved over the entire UWB band, the radiation characteristics considerably vary in the band. Referring to a radiation pattern diagram in FIG. 5(b) of Non-Patent Document 2, the gain in a 225-degree direction decreases by 6 dB at 5 GHz, and by as much as 15 dB at 7 GHz, as compared to a reference gain value at 4 GHz. This phenomenon results from the fact that the main beam direction varies depending on frequency, and the higher the frequency increases, the lower the half-width of the main beam decreases. Thus, it is extremely difficult to stably establish communication conditions over the entire band.
In the fifth prior art example, although the band-stop function in a partial band is achieved in a printed monopole antenna, the stable radiation characteristics in the band cannot be expected, since the structure of the fifth prior art example is the same in principle as that of the fourth prior art example.

Wide-band slot antenna apparatus with stop band


A method and apparatus are provided for indicating disbonds in joint regions. A critical bondline region is located between a first material and a second material having a higher acoustic impedance than the first material. A form member having an acoustic impedance which is substantially similar to the first material has a first face which is form fitted to a surface of the first material opposite to and non-parallel with the critical bondline region. The form member has an opposite second face which is shaped to be parallel to the critcal bondline region. Transducers are acoustically coupled to the second face of the form member to generate an ultrasonic tone burst through the acoustically similar form member and first material which is reflected by the critical bondline region. This reflected tone burst is received and a resulting signal is compared with a normal signal for no disbond to determine the presence of an unacceptable disbond.

1. Technical Field of the Invention
The present invention relates generally to disbond measuring and more particularly to a method of measuring disbonds in joint regions.
2. Discussion of the Related Art
Disbonds constitute a major threat to the structural integrity of a multi-element component. Visual inspection of the component for disbonds is often not possible since the joint regions are surrounded by other elements. Non-visual techniques such as tangential x-ray or ultrasound inspection have been unsuccessful in accurately detecting joint disbonds, especially in complex geometry joint areas such as those existing in solid rocket motors (SRMs). Specifically, artifacts such as fluorescence near the edges of the component prevent any meaningful application of tangential x-ray techniques. All previous attempts employing ultrasound have met with failure.

Method and apparatus for indicating disbonds in joint regions


A filtering pulley assembly for an accessory drive of a vehicle has a hub fixedly attachable to a rotating shaft, a pulley mounted coaxial and freely rotating on said hub, an actuator disc carried by the hub, a plurality of elastic assemblies interposed between the pulley and the actuator disc, and a torque limiting coupling configured to rotationally connect the actuator disc to the hub, when the torque is below a predetermined threshold value, and to decouple the actuator disc from the hub, when the torque is above the threshold value.

As is known, the drive shaft in internal combustion engines is subject to torsional vibrations due to the periodic stress caused by the combustion in the cylinders. Said vibrations are particularly intense at start-up and at low speeds.
The torsional vibrations result in rotation irregularities of the drive pulley of the accessory drive which are transmitted to the accessories by means of the drive belt, which is therefore subject to periodic variations in tension.
The accessories generally comprise an electric machine operating as an alternator and if necessary as a starter motor, and the compressor of the conditioning system. Overloads on the belt can be generated not only by the torsional vibrations of the drive shaft, but also by violent accelerations/decelerations of said drive shaft, due to the inertia of the accessories.
In order to "filter" the torsional oscillations transmitted by the drive shaft to the belt, a filtering pulley assembly is generally used as drive pulley provided with a hub integral with the drive shaft, a pulley cooperating with the belt and a filtering unit interposed between the hub and the pulley. The filtering unit can comprise one or more elastic elements via which the torque is transmitted from the hub to the pulley; said elastic elements can consist of spiral springs or helical springs arranged circumferentially.
Filtering pulley assemblies are also used to drive the electric machine, which is the accessory with the greatest inertia. Said pulley assembly comprises a hub adapted to be connected to the rotor of the electric machine, a pulley provided with a profile adapted to cooperate with the belt, and a filtering unit provided with one or more elastic elements interposed between the hub and the pulley.
In the conventional applications in which the electric machine consists of an alternator, it is known to incorporate in the filtering unit a free wheel adapted to unidirectionally transmit the movement from the pulley to the hub (normal operating condition) but to decouple the hub from the pulley in the event of inversion of the torque. The free wheel can be provided, for example, by means of a band spring carried either by the hub or the pulley and adapted to expand or contract according to the direction of the torque to cooperate with, or decouple from, a corresponding annular friction surface integral with the other between the hub and the pulley.
In the latest systems, the electric machine is increasingly frequently of reversible type, and is used, according to the operating conditions, as an alternator or motor (operating as a starter motor and/or booster). This makes it impossible to use a filtering unit with free wheel because it would decouple the electric machine, when used as a motor, from the belt drive.

Filtering pulley assembly for a belt drive


A power over Ethernet controller comprising: control circuitry; at least one temperature sensor operatively connected to the control circuitry; and a plurality of electronically controlled switches responsive to the control circuit, each of the electronically controlled switches enabling power to a respective port and having associated therewith inrush current limiting functionality, the control circuit being operative to input at least one temperature indication from the at least one temperature sensor; operate at least one of the plurality of electronically controlled switches thereby enabling power to a first port; and delay a time period dependent on the at least one temperature indication, whereby operation of a second of the plurality of electronically controlled switches to enable power to a second port is permitted only after the delayed time period.

The present invention relates to the field of powering ports, and more particularly to a controller having a plurality of on-board electronically controlled switches and a dynamic algorithm for powering a plurality of ports.
The growth of local and wide area networks based on Ethernet technology has been an important driver for cabling offices and homes with structured cabling systems having multiple twisted wire pairs. The ubiquitous local area network, and the equipment which operates thereon, has led to a situation where there is often a need to attach a network operated device for which power is to be advantageously supplied by the network over the network wiring. Supplying power over the network wiring has many advantages including, but not limited to; reduced cost of installation; centralized power and power back-up; and centralized security and management.
Several patents addressed to this issue exist including: U.S. Pat. Ser. No. 6,473,608 issued to Lehr et al., whose contents are incorporated herein by reference and U.S. Pat. Ser. No. 6,643,566 issued to Lehr et al., whose contents are incorporated herein by reference. Furthermore a standard addressed to the issue of powering remote devices over an Ethernet based network has been published as IEEE 802.3af -2003, whose contents are incorporated herein by reference.
An Ethernet switch or midspan module providing power over Ethernet functionality is typically designed to support a plurality of ports, and power is preferably to be supplied to compatible equipment rapidly after detection. Power is typically supplied under control of a power over Ethernet controller, the power over Ethernet controller energizing for each port to be powered an electronically controlled switch, which in an exemplary embodiment comprises a power MOSFET. In another embodiment the electronically controlled switch comprises a FET or bipolar transistor. At port start up, the inrush current to a remotely powered device, which typically comprises a large input capacitor, must be limited. In order to reduce cost and minimize the footprint, preferably the required electronically controlled switches are provided embedded within the power over Ethernet controller. Unfortunately, embedding a plurality of electronically controlled switches having associated therewith inrush current limiting functionality leads to thermal issues that must be dealt with.
What is needed, and not supplied by the prior art, is a controller having a dynamic start up algorithm, which enables rapid turn on of a plurality of electronically controlled switches, while taking into account thermal requirements.

Electronically implemented dynamic start up method for ports with inrush current limiting functionality

Microsemi Corp. - Analog Mixed Signal Group, Ltd.


The present invention provides a method, apparatus, and computer instructions for recovering an image of partition configuration information data for a set of partitions having at least one affinity partition in a logical partition data processing system. (Damage to an image of partition configuration data is detected. Current partition data is compared with a backup partition data. A merger of the current partition configuration data is made with the backup logical partition data if a conflict is present between the current partition configuration data and the backup partition data. The merger is performed in a manner avoiding stopping an operation on a running partition in the set of partitions.

1. Technical Field
The present invention relates generally to an improved data processing system and in particular, a method, apparatus, and computer instructions for managing configuration data. Still more particular, the present invention provides a method, apparatus, and computer instructions for recovering logical partition data in a logical partitioned data processing system.
2. Description of Related Art
A logical partitioned (LPAR) functionality within a data processing system (platform) allows multiple copies of a single operating system (OS) or multiple heterogeneous operating systems to be simultaneously run on a single data processing system platform. A partition, within which an operating system image runs, is assigned a non-overlapping subset of the platform's resources. These platform allocable resources include one or more architecturally distinct processors with their interrupt management area, regions of system memory, and input/output (I/O) adapter bus slots. The partition's resources are represented by the platform's firmware to the OS image.
Each distinct OS or image of an OS running within the platform is protected from each other such that software errors on one logical partition cannot affect the correct operation of any of the other partitions. This is provided by allocating a disjoint set of platform resources to be directly managed by each OS image and by providing mechanisms for ensuring that the various images cannot control any resources that have not been allocated to it. Furthermore, software errors in the control of an operating system's allocated resources are prevented from affecting the resources of any other image. Thus, each image of the OS (or each different OS) directly controls a distinct set of allocable resources within the platform.
With respect to hardware resources in a LPAR system, these resources are disjointly shared among various partitions, themselves disjoint, each one seeming to be a stand-alone computer. These resources may include, for example, input/output (I/O) adapters, memory dimms, nonvolatile random access memory (NVRAM), and hard disk drives. Each partition within the LPAR system may be booted and shutdown over and over without having to power-cycle the whole system.
The LPAR system may have two types of partitions, a logical type of partition and an affinity partition. Logical partitions are user-defined system resource divisions. With respect to logical partitions, a user determines the number of processors, memory, and I/O that a logical partition can have when the logical partition is active. An affinity partition is a special type of logical partition. Affinity partitions are divisions of system-defined resources that have a close physical proximity. When an affinity partition is created, the system determines the number of processors and memory that that partition can have, but the user determines the I/O requirements for this type of partition.
Configuration data for partitions are typically stored in a nonvolatile random access memory (NVRAM) for a service processor. When configuration data is needed, this data is pulled from the NVRAM to the hardware management console used to manage the LPAR data processing system. Situations occur in which this NVRAM may be cleared or corrupted. As a result, a recovery action is required for these situations. Otherwise, users are required to recreate this partition configuration data every time such a loss occurs.
Currently, a current image copy of the configuration data is saved on some regular basis to allow recovery of the configuration data when a loss is detected. Currently available recovery processes require stopping operations on the partitions while performing recovery processes because these recovery processes may overwrite configuration data for partitions currently executing. Situations occur, however, in which users are running critical or important operations on an affinity partition, and it is desirable to avoid stopping execution of that partition to restore configuration data.
Normally, profile data is merged to recreate or restore configuration data. With affinity partitions, in many cases, only a limited number of affinity partitions may be allowed. If the mirror image and the backup image have significant differences, a situation in which the number of affinity partitions may be greater in the restored profile than what is allowed or partition configuration data is inconsistent with partition types. Such situations put systems in inconsistent states. User may not able to recover from the situation. When this situation happens, users will not able to continue on using hardware management system to manage the partitions. In order to get out of this situation, users will have initialize the system which in turn stops all running partitions, delete them, and create them according to the configuration users have saved away.
With current recovery mechanism, it simply combines configuration data from backup and mirror images. With no knowledge of affinity partitions, this recovery mechanism simply overwrites the partition types that are currently defined. Because a partition type cannot be changed at runtime, the result of modifying the partition type would put the system and the partitions in undesirable and inconsistent states. This situation may indirectly cause termination of partition in order to put system back to a consistent state.
Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for recovering configuration data in LPAR systems containing affinity partitions without interrupting operations on those partitions.

Method and apparatus for recovering logical partition configuration data

International Business Machines Corporation


The present invention relates to a device and method for detecting analytes in a sample.

1. Field of the Invention
The present invention discloses a device and method for detecting analytes in a sample.
2. Description of Related Art
Antibiotics are used for combating infectious diseases, both in humans and in animals. It is well known that misuse of antibiotics such as administration of antibiotics whenever this is not required from a medical point of view or incomplete courses of treatment is the most important cause of the development of antibiotic resistance. Thus, methods for detecting the presence of antibiotics in samples such as e.g. milk, blood, fish, feed, meat, serum, urine, water and the like are of utmost importance in the prevention of the unwanted spread of antibiotics. In many areas, this process of detection can only be performed adequately, if a fast and simple test is available. In general, there are two types of tests suitable for routinely monitoring the presence of antibiotics in samples. Firstly, there are microbial inhibition tests, wherein a test microorganism is contacted with the sample to be tested and the growth (or inhibition of growth) of the microorganism is observed, for instance with the use of an indicator. An example of such a test is described in EP 0 755 456 B1. The major drawback of microbial inhibition tests is that it takes a relatively long time to obtain results.
Secondly, there are competitive immunoassays, wherein the antibiotic to be tested and a reference antibiotic present in the test compete for binding with binding proteins and/or antibodies with affinity for the antibiotics. Visualization is usually done by means of labeling. One of many examples of such a test is described in EP 0 593 112 B1. Although these types of tests are in general faster than microbial inhibition tests, they still require extensive handling by the end user and are therefore not user friendly.
In view of the above, it is clear that there exists considerable room for improvement in the area of antibiotic testing, particularly where it concerns to ease-of -use, speed and convenience.


A process cartridge for use in a printing machine is provided. The process cartridge further includes a plurality of rivets. Each of the plurality of rivets includes a retaining portion thereof. At least one of the first housing portion and the second housing portion define an aperture for passage of the retaining portion of at least one of the rivets therethrough. The other of at least one of the first housing portion and the second housing portion define a cavity for receiving the retaining portion of the at least one rivet. The portion of the housing defining the cavity being interferencely fitted to the retaining portion of the at least one rivet.

The present invention relates to a method and apparatus for remanufacturing process cartridges. More specifically, the invention relates to securing covers of process cartridges.
In the well-known process of electrophotographic printing, the charge retentive surface, typically known as a photoreceptor, is electrostatically charged, and then exposed to a light pattern of an original image to selectively discharge the surface in accordance therewith. The resulting pattern of charged and discharged areas on the photoreceptor form an electrostatic charge pattern, known as a latent image, conforming to the original image. The latent image is developed by contacting it with a finely divided electrostatically attractable powder known as xe2x80x9ctoner.xe2x80x9d Toner is held on the image areas by the electrostatic charge on the photoreceptor surface. Thus, a toner image is produced in conformity with a light image of the original being reproduced. The toner image may then be transferred to a substrate or support member (e.g., paper), and the image affixed thereto to form a permanent record of the image to be reproduced. Subsequent to development, excess toner left on the charge retentive surface is cleaned from the surface. The process is useful for light lens copying from an original or printing electronically generated or stored originals such as with a raster output scanner (ROS), where a charged surface may be imagewise discharged in a variety of ways. In a printer, as the toner within the developer material is transferred to the photoreceptor and eventually to the copy paper, this used toner must be replaced. The printer thus includes a container or cartridge from which fresh toner is dispensed into the machine. To provide for a small, compact cartridge and to provide for a cartridge in which the cartridge may be easily removed, the cartridge typically has a compact shape.
Service costs represent a significant portion of the cost associated with operating a printing machine. Certain components represent those most likely to require service. By providing a method of easily replacing those certain components, the operator may replace those components himself, avoiding service technician labor costs.
These certain components are consolidated within a housing that may be easily replaced by the customer. This housing is typically called a customer replaceable unit (CRU). For example, in addition to toner, components that may be included in a CRU are the charging device (a corotron or a bias charge roll), and the photoreceptor.
A CRU may be changed several times during the life of a copy machine. While a few of the components within a CRU are consumed during the life of the CRU many of the components may be reused. Therefore, CRUs are now being frequently remanufactured rather than being made from all completely new components. The remanufacturing includes replacing spent components and inspecting all components that may wear. Worn components are replaced if so required.
Copy machines and printing machines include components that wear or become spent or consumed during normal use. For copying and printing machines such components that are consumed or become spent include developer material including toner and, if appropriate, carrier as well as the photoconductive member in the form of either a belt or a drum. Addition components may also wear during the life of the copying and printing machine. Such components include cleaning blades and brushes as well as charge corotrons and fuser rolls.
As mentioned above, to reduce service costs, improve copy quality and to improve the reliability and running time of copying and printing machines, certain components that wear, become consumed or are spent are grouped into a subassembly which may be readily replaced by a minimally trained operator. These groups of components are typically grouped into a housing which is easily insertable into the machine. These assemblies are typically called CRUs or process cartridges.
The housings in which the wear and spent components are placed to form the process cartridge typically are very durable and have a very long life. Since the process cartridge is replaced several times during the life of the machine, a large number of spent or consumed process cartridges accumulate during the life of machines, particularly those which have large quantities of machines manufactured.
During remanufacture, the process cartridges are disassembled and worn components replaced. To provide for replacement of the wear and consumable components, the housings of the process cartridges typically include upper and lower halves which are opened to install or replace components and closed after the components are replaced so the cartridge may function.
The upper and lower portions of the process cartridge housing must be securely fastened to each other. Several attempts have been made to join the upper and lower portions of a process cartridge. For example, the upper and lower portions of the cartridges may be sealed by an adhesive, for example, a glue. Also the upper and lower portions of the process cartridge may be tack welded to each other. The use of glues or tack welds in securing an upper and lower portion of a process cartridge may not provide for a secured joint. The upper and lower portions may break loose from each other when glue or tack weld is used.
Another common method of joining an upper and lower portion of a process cartridge is the use of screws, for example, self-tapping screws. Self-tapping screws have a series of problems. For example, when assembling the screws, particularly when using automated equipment, the equipment to tighten the screws may cause the screws to overtighten and strip. Further, with the use of screws, a screw can back out or become loose during shipment or use when vibration is present when the process cartridge is in use.
The following disclosures may be relevant to various aspects of the present invention:
U.S. Pat. No. 5,774,766 discloses a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus comprises an electrophotographic photosensitive drum, a development roller for developing a latent image formed on the electrophotographic photosensitive drum, a toner accommodating portion for accommodating toner to be used by the development roller for development, a photosensitive drum frame for supporting the electrophotographic photosensitive drum, a development frame including the toner accommodating portion, and a support frame including a first toner leakage preventing member positioned at one longitudinal end of the development roller and a second toner leakage preventing member positioned at the other longitudinal end of the development roller. The development frame and the support frame are rotatably connected about a positioning member and, in this connected state, a portion of the development frame is welded to a portion of the support frame so that the development frame and the support frame are joined together.
U.S. Pat. No. 5,729,795 discloses electrostatographic cartridges having a cartridge base, a toner hopper having a toner fill hole attached to the cartridge base, and a gear housing assembly which blocks access to the toner fill hole and which includes an interior gear housing component integral with the cartridge base are remanufactured by severing the interior gear housing component and then reattaching it to the cartridge base through the exterior gear housing component. Specifically, the one-piece interior gear housing component is severed so that it can be removed thereby providing unobstructed access to the original toner fill hole. Most preferably, the interior part of the gear housing is cut at a five degree angle relative to the cartridge base. The angular cut thereby ensures that the attachment bosses on the cartridge base which serve to couple the base to the toner cartridge cover are not damaged to an extent that would defeat their coupling function. Paired reattachment holes are formed in the interior and exterior gear housing components to allow them to be reattached to one another via screw and nut assemblies extending therethrough. The reattached interior and exterior gear housing components may then be connected to the cartridge base by screws supplied originally with the cartridge by original equipment manufacturer (OEM). In such a manner, fresh toner may be introduced into the toner hopper in a convenient fashion during the remanufacturing operation.
U.S. Pat. No. 5,619,309 discloses a process cartridge mountable to an image forming apparatus. The apparatus includes an image bearing member, process means acting on the image bearing member, and a plurality of frames for constituting a housing for the image bearing member and the process means. A projection is provided along an abutment portion of one of the frames to be welded.
U.S. Pat. No. 5,564,847 discloses a printer having a printhead which traverses laterally across a sheet-like print medium and which thereby defines a laterally-extending print zone across the print medium. A paper transport mechanism in the printer has drive rollers and associated pinch wheels to drive the print medium through the printer""s print zone. The paper transport mechanism further includes an upper print media guide and a lower print medium guide. The two print medium guides are shaped at their transverse ends to bow the transverse edges of the print medium downwardly to reduce its tendency to buckle upwardly into the printhead. In order to fit the upper print medium guide into the limited available space above the drive rollers, it is made of a lower molded portion for paper contact and an upper backing portion for rigidity. A pinch finger extends toward the printer""s print zone beyond the pinch wheels to establish a pinch point against the drive roller in near proximity to the print zone. To facilitate ejection of printed pages, the upper print medium guide is formed with a series of ribs which contact the paper. The ribs reduce friction and static buildup, and make it easier to push the paper from the paper transport mechanism.
U.S. Pat. No. 5,561,496 discloses an assembling method of an image forming apparatus for forming an image on a recording material includes preparing a frame, a feeding unit having a feeding roller, electrical component unit having electrical components and an outer cover; mounting the feeding unit and the electrical component unit to the frame from a position of the frame which takes a bottom position upon installation of the image forming apparatus; and then overturning of the frame; mounting the outer cover to the frame from a position which takes a top position upon installation of the frame.
U.S. Pat. No. 5,527,123 discloses a printer having a printhead which traverses laterally across a sheet-like print medium and which thereby defines a laterally-extending print zone across the print medium. A paper transport mechanism in the printer has drive rollers and associated pinch wheels to drive the print medium through the printer""s print zone. The paper transport mechanism further includes an upper print media guide and a lower print medium guide. The two print medium guides are shaped at their transverse ends to bow the transverse edges of the print medium downwardly to reduce its tendency to buckle upwardly into the printhead. In order to fit the upper print medium guide into the limited available space above the drive rollers, it is made of a lower molded portion for paper contact and an upper backing portion for rigidity. A pinch finger extends toward the printer""s print zone beyond the pinch wheels to establish a pinch point against the drive roller in near proximity to the print zone.
U.S. Pat. No. 5,311,265 discloses a toner loading system for use with reprographic machines which reduces powder clouding and minimizes toner spill during loading. A toner cartridge is mountable on a toner housing. The housing includes an opening sized to accept the cartridge. When in a raised position, the cartridge is on top of the housing. When in a lowered position, the cartridge is positioned within the housing through the opening. A removable seal on the bottom of the cartridge includes a long pull tab which can be grasped from above the housing, when the cartridge is lowered, to allow removal of the seal and allow flow of toner from the cartridge to the housing while the cartridge is extended substantially or completely within the housing, thus reducing powder clouding, providing more even toner flow, and reducing mess or spillage. The reduced powder clouding is due to a substantially reduced height from which the toner has to fall when being loaded into the housing.
U.S. Pat. No. 5,296,902 discloses an apparatus and method for providing a removable closure seal between the toner hopper and the toner feed roller compartment of a toner cartridge assembly used in printers, copy machines and facsimile machines. The seal prevents toner from leaking from the toner hopper into the feed roller compartment during shipping and handling. In one embodiment, the seal has a slotted seal insert placed over the passage between the hopper and roller compartment. A removable tape closes the slot. In another embodiment, a slotted seal insert is slid between grooves in the toner cartridge assembly into position between the hopper and feed roller compartment. The insert is attached to the cartridge assembly by glue, tape, or other adhesive. An insert tool is used to facilitate this attachment. A reusable, removable closure seal is slid between the grooves to close the slot. The closure seal may have a metal spine to increase its rigidity. A crush-resistant velvet material with a foam backing is used to improve the seals at the ends of the feed roller compartment.
As will be seen from an examination of the prior art, it is desirable to provide an electrostatographic copying system with a toner cartridge having a resealing system that is simple, reliable, and inexpensive. The present invention is directed to overcoming at least some of the aforementioned problems.
In accordance with one aspect of the present invention, there is provided a process cartridge for use in a printing machine. The process cartridge includes a first housing portion including a first housing attachment surface and a second housing portion including a second housing attachment surface. At least a portion of the second housing attachment surface is associated with at least a portion of the first housing attachment surface. The process cartridge further includes a plurality of rivets. Each of the plurality of rivets includes a retaining portion thereof. At least one of the first housing portion and the second housing portion define an aperture for passage of the retaining portion of at least one of the rivets therethrough. The other of at least one of the first housing portion and the second housing portion define a cavity for receiving the retaining portion of the at least one rivet. The portion of the housing defining the cavity being interferencely fitted to the retaining portion of the at least one rivet.
In accordance with yet another aspect of the present invention, there is provided an electrophotographic printing machine of the type including a process cartridge. The process cartridge includes a first housing portion including a first housing attachment surface and a second housing portion including a second housing attachment surface. At least a portion of the second housing attachment surface is associated with at least a portion of the first housing attachment surface. The process cartridge further includes a plurality of rivets. Each of the plurality of rivets includes a retaining portion thereof. At least one of the first housing portion and the second housing portion define an aperture for passage of the retaining portion of at least one of the rivets therethrough. The other of at least one of the first housing portion and the second housing portion define a cavity for receiving the retaining portion of the at least one rivet. The portion of the housing defining the cavity being interferencely fitted to the retaining portion of the at least one rivet.
In accordance with another aspect of the present invention, there is provided a method for manufacturing process cartridge for use in a printing machine. The method includes the steps of providing a plurality of rivets each of the rivets having a head and a retaining portion, providing a first portion of a process cartridge, the first portion defining an aperture, providing a second portion of a process cartridge, the first portion defining a cavity, passing the retaining portion one of the plurality of rivets through the aperture, inserting the retaining portion of one of the plurality of rivets into the cavity, seating the head of the one of the plurality of rivets against the first portion of the process cartridge, and securing the retaining portion of one of the plurality of rivets to the second portion of a process cartridge, thereby securing the first portion of a process cartridge to the second portion of the process cartridge.
In accordance with yet another aspect of the present invention, there is provided a method for remanufacturing a process cartridge utilizing a plurality of rivets for assembly thereof. The method includes the steps of disassembling the used process cartridge, inspecting internal components of the process cartridge, performing at least one of repairing and replacing at least one of the internal components of the process cartridge, assembling the internal components of the process cartridge into at least one of a first housing portion and a second housing portion, tack welding the first housing portion of the process cartridge to the second housing portion of the process cartridge, testing the process cartridge, breaking the tack welds if the process cartridge fails the testing step, performing at least one of repairing and replacing any components that fail at the testing step, retack welding the first housing portion of the process cartridge to the second housing portion of the process cartridge if the breaking step is required, repeating the testing step, the breaking step, the performing step and the retack welding step as required, passing the retaining portion one of said plurality of rivets through the aperture, inserting the retaining portion of one of said plurality of rivets into the cavity, seating the head of the one of said plurality of rivets against the first housing portion of the process cartridge; and securing the retaining portion of one of said plurality of rivets to the second housing portion of the process cartridge, thereby securing the first portion of the process cartridge to the second housing portion of the process cartridge.
In accordance with yet another aspect of the present invention, there is provided a rivet for use in a process cartridge for use in a printing machine. The rivet includes a body, a head attached to one end of the body and a retaining portion attached to the body and spaced from the retaining portion. The head has a shape selected to inhibit the removal of the rivet from the process cartridge by rotating the rivet with respect to the cartridge.


A system and method for producing white light in an adjustable light emitting diode (LED) illumination device is provided. The system and method varies the “off” time for one of multiple sets of light emitting diodes (LEDs) or channels in succession in order to compensate for and stabilize the color-shifting or degradation that gradually occurs in LEDs. Each channel corresponds to a different color. By varying the “off” time of only one channel at a time, the system efficiently utilizes the majority of the LEDs, thereby enabling the production of a more stable white light with fewer LEDs.

In solid state lighting devices, including a plurality of LEDs of different colors, control of both intensity and color is commonly achieved using pulse width modulation (PWM). Such PWM control is well-known, and indeed, commercial PWM controllers have long been available specifically for driving LEDs. See, e.g., Motorola Semiconductor Technical Data Sheet for MC68HC05D9 8-bit microcomputer with PWM outputs and LED drive (Motorola Ltd., 1990). In PWM, a train of pulses is applied at a fixed frequency, and the pulse width (that is, the time duration of the pulse) is modulated to control the time-integrated power applied to the light emitting diode. Accordingly, the time-integrated applied power is directly proportional to the pulse width, which can range between 0% duty cycle (no power applied) to 100% duty cycle (power applied during the entire period).
Known PWM illumination control has certain disadvantages. In particular, known systems and methods introduce a highly non-uniform load on the power supply. For example, if the illumination source includes red, green, and blue illumination channels and driving all three channels simultaneously consumes 100% power, then at any given time the power output may be 0%, 33%, 66%, or 100%, and the power output may cycle between two, three, or all four of these levels during each pulse width modulation period. Such power cycling is stressful for the power supply, and dictates using a power supply with switching speeds fast enough to accommodate the rapid power cycling. Additionally, the power supply must be large enough to supply the full 100% power, even though that amount of power is consumed only part of the time.
Power variations during PWM may be avoided by diverting current of each "off" channel through a "dummy load" resistor. However, the diverted current does not contribute to light output and hence introduces substantial power inefficiency.
Known PWM control systems are also problematic as relating to feedback control. To provide feedback control of a color-adjustable illumination source employing known PWM techniques, the power level of each of the red, green, and blue channels must be independently measured. This typically dictates the use of three different light sensors each having a narrow spectral receive window centered at the respective red, green, and blue wavelengths. If further division of the spectrum is desired, the problem becomes very expensive to solve. If, for instance, a five channel system has two colors that are very close to one another, only a very narrow band detector is able to detect variations between the two sources.
In order to overcome these problems, one known illumination system utilizes a multi-channel light source having different channels that generate illumination of different colors corresponding to the different channels. The system includes a power supply that selectively energizes the channels by utilizing time division multiplexing (TDM) to generate illumination of a selected time-averaged color. However, this system was designed to cover a large color space. In order to achieve this large color space, the system uses TDM to selectively vary the "on" time of one individual LED color at a time for a specified duration. Therefore, because only one color of LED is used at a time, a large number of LEDs are required to produce some colors, particularly white light. Further, while this approach can provide any color within the full range of available LED chips, it has a low utilization of LEDs. This large quantity of LEDs provides a large Gamut, but does not make efficient use of LEDs.
Therefore, there remains a need for an illumination system that economically and effectively produces white light by concurrently utilizing a majority of the LED chips in the system. There also remains a need for an illumination system that quickly and efficiently stabilizes the color-shifting or degradation that gradually occurs in LEDs.

Rolling blackout adjustable color LED illumination source


A cushioning device as in a pillow that has a main-body foam which a plurality of projections extend off a surface of the main-body. The projections are arranged in different support characteristic groupings such as rows of different volume or sized projections (e.g., cylindrical, cubical, prismatic, etc.) spaced out over a surface (e.g., convex surface) of the pillow (one or more surface sections as in upper surface sections and front edge surface section). There is also preferably provided a neck support ridge extension. The cylindrical projections are arranged such that a greater number of smaller volume, width or diameter, etc. rows of projections are centrally positioned on the surface and with the larger volume, width, or diameter, etc. projections laterally outward of the more centrally positioned projections, and with the ridge extension preferably extending along a front edge (e.g., commensurate with the extreme front edge surface or to some extent back in a front edge region of the front edge) of the pillow for a full length of the pillow.

Pillows come in a variety of forms, with the more typical consisting of rectangular, fabric enclosures filled with feathers, down, chipped foam, or a polyester fill in a traditional overall shape (e.g., converging corners and a convex upper surface presented when supported on a bed). These pillows may be re-shaped by the user to provide reasonably adequate support for the user while the user falls asleep. However, many people suffer from an uncomfortable night's sleep because of the inadequate support that their head and neck receive while using these traditional pillows throughout the night. This is because traditional pillows either have a body that is so soft that the neck support area compresses to result in no support, or the body is so firm that the head sits considerably higher than the shoulders of the user, resulting in an abnormal sleeping position. Chronic neck pain or stiffness and a tense upper back are often the result of these inadequate forms of support these traditional pillows provide.
Various foam pillows have also been developed that comprise a foam body taking the place of the above-noted fillers and inserted into a fabric enclosure. These foam body pillows include polyurethane foam pillows (e.g. Omalux® high density foam sold by Carpenter Co. of Richmond, Va.) and also include visco-elastic foam pillows (e.g. the "PERFECT PILLOW® comfort support device and the ISOTONIC® pillow also sold by Carpenter Co.). Foam based pillows avoid problems such as filler clumping and can facilitate washing by allowing for easier removal of the pillow support from its fabric enclosure. However, even with a high quality foam body such as the polyurethane foam pillows noted above, the pillow can be deemed by some users to not adequately support the head and shoulders in a manner that is most comfortable to the user. This is because the prior art foam pillows are designed to generally present singular or unitary support characteristics over an entire head contact surface area of the pillow, and most prior art foam pillows are generally not well suited for heat dissipation. In an effort to provide added comfort, the prior art has relied upon expense increasing features as in, the addition of ventilation holes and/or extra layers of added material and/or added components such as adjustable air bladders. Thus, the foam pillows of the prior art are not well suited to provide varying degrees of support at targeted portions of the pillow to provide more comfortable support and/or have a tendency to provide poor heat dissipation and/or present highly complex and overly expensive designs.
Various examples of combination pillows can be seen in the multiple foam type/multiple layer arrangement in U.S. Pat. No. 5,689,844, the composite pillow of U.S. Pat. No. 4,777,855 and the visco-elastic pillow with added inflatable air bladder of U.S. Pat. No. 6,327,725.


A sensor isolation system including a sensor, a package for the sensor, and a compliant interposer disposed between the sensor and the package and interconnecting the sensor to the package to isolate the sensor from thermal and mechanical stresses and yet at the same time providing a physical interconnect between the sensor and the package.

Micro-electro-mechanical (MEM) dies, such as gyroscopes and accelerometers are typically very small and sensitive to thermal and mechanical stresses. In the prior art, the sensor die is rigidly mounted to the floor or substrate of a ceramic chip carrier package to maintain axis alignment, bias stability, and scale factor stability with respect to the package over time and temperature variations. The mounting scheme used strives to maintain rigidity and stability over a wide range of environmental conditions, such as temperature cycling, vibrational stresses, and g-loading. At the same time, the package should not impart any significant stresses on the sensor over these same environmental conditions. Furthermore, any minor stresses that do occur should be stable and cannot exhibit any hysteresis effects which would affect performance of the sensor.
As stated above, the MEM die, such as a gyroscope or accelerometer sensor, is typically directly bonded to the package, or chip carrier. Aluminum oxide is often used as the material for a fabricating a hermetic chip carrier for such MEM devices. In some cases, a small mounting pad may be placed between the floor of the chip carrier and the sensor in an attempt to absorb various stresses and strains which occur during the operation of the device. Another prior art technique to reduce thermal stress on the sensor is to braze the sensor directly to a package made of a material more closely matching the thermal expansion coefficient of the sensor, such as aluminum nitride.
These prior art techniques exhibit several distinct disadvantages. When the sensor is directly bonded to the package, a large thermal stress develops because the thermal expansion coefficient of the package often greatly exceeds the thermal expansion coefficient of the sensor. Furthermore, the braze materials may impart similar thermal stress as stated above. The result is warping of the sensor which adversely affects its performance. This prior art technique also makes the sensor susceptible to any externally applied forces.
Prior art techniques which attempt to reduce thermal and mechanical stresses by utilizing a small pad near the center of the sensor require precise control of the quantity of solder used, as well as precise control of the placement of the die. Using this prior art technique, localized attachment is susceptible to alignment shifts due to stress relaxation of the brazed connection.
If expensive aluminum nitride is used as the package material because this material has a thermal expansion coefficient which more closely matches the thermal coefficient of the sensor, the result is a package which can cost as much as eight times more than an aluminum oxide package.
Additionally, brazing the die to the floor of the package still leaves it susceptible to strains and stresses due to the flexing of the package or chip carrier floor. Finally, the prior art techniques do not always adequately control thermal stresses, are not easily scalable to large size dies, are not mechanically robust, and can be expensive to implement because they require specialized materials and/or assembly methods.

This patent is subject to a terminal disclaimer.

The Charles Stark Draper Laboratories, Inc.


A light emitting device driving circuit, includes: a switch device, a comparator, a driving module, a time counting circuit and a compensation module. The switch device is turned on or off according to a control signal for controlling a driving current flowing through the light emitting device. The comparator generates a comparison result according to a reference voltage and a feedback voltage corresponding to the driving current. The driving module generates the control signal according to the comparison result. The time counting circuit controls the driving module to turn on the switch device after the switch device turns off for a predetermined time. The compensation module detects a turn on time for the switch device and a delay time between the feedback voltage reaching the reference voltage value and the control signal varying correspondingly, and adjusts the reference voltage according to the turn on time and the delay time.

1. Field of the Invention
The present invention relates to a light emitting device driving circuit, and particularly relates to a light emitting device driving circuit, which has a compensation mechanism.
2. Description of the Prior Art
In a conventional driving circuit for a light emitting device (for example, a light emitting diode), a PWM (Pulse Width Modulation) circuit is utilized to control a switch device for controlling the current flowing through the light emitting device. Also, a comparator is utilized to compare a reference voltage with a feedback voltage proportional to the current to determine if the current should decrease or increase. Such a technique is a well-known controlling technique called peak-current controlling technique. This technique has many disadvantages, however. For example, the current ripple based on this structure substantially varies if input voltage varies and the input voltage of the light emitting device may be unfortunately an AC voltage, so the current accuracy control and the endurance of the light emitting device may be negatively affected. Moreover, the PWM circuit operates at a fixed frequency, such that the circuit will cause stronger electromagnetic interference to other devices. Besides, an oscillation may occur if the switch device is accidentally turned on when it is expected to be off.
FIG. 1 is a circuit diagram illustrating a driving circuit of prior art for a light emitting device. As shown in FIG. 1, the light emitting device driving circuit 100 includes a comparator 101, a driving module 103 and a time counting circuit 105. The comparator 101 compares a feedback voltage Vfb (which is generated according to the resistor 108 and a driving current I) and a reference voltage Vref, and controls the driving module 103 to output a control signal VG for controlling the switch device 107, thereby controlling the current I flowing through the light emitting device 109 and the inductor 111. The light emitting device driving circuit 100 further includes a time counting circuit 105 that controls the driving module 103 such that the switch device 107 will be turned on again after being turned off for a predetermined period of time. The resistor 106 is used to adjust the predetermined period of time, and such a technique is a well-known skill called constant-off time.
The advantage of this method is that, since the turn off time is constant, the range of the current ripple will not change as input voltage changes, and the problem of poor current accuracy may be avoided. Also, since the operation frequency of the PWM circuit in FIG. 1 is not fixed, the circuit will cause less electromagnetic interference problem. Furthermore, since the decreasing rate of the driving current is almost fixed, switch device 107 may not be accidentally turned on, avoiding the above-mentioned problem of oscillation.
However, the structure in FIG. 1 may have some problems. FIG. 2 illustrates a current-time relation of the driving circuit of prior art for a light emitting device. As shown in FIG. 2, the maximum value of the current I is originally set to be ISU. In view of signal propagation, the circuit in FIG. 1 always has a delay time starting at the time when the feedback voltage Vfb reaches the reference voltage Vref and ending at the time when the control signal VG really turns off switch device 107. Thus, during the delay time, current I will exceed the originally-set ISU and finally reach Imax. As mentioned before, the turn off time toff is set as a constant such that Imin is a function of Imax. Thus, the real mean driving current (=(Imax+Imin)/2) will exceed the expected mean driving current Imean (˜(Imax+Imin)/2). The difference between the real and expected mean driving currents implies driving current inaccuracy. The larger the input voltage Vin, the more significant the driving current inaccuracy.

Driving circuit for light emitting device with compensation mechanism and driving method thereof