A disposable, flexible locking restraint having a base and first and second straps integrally molded of a dry flexible plastic is provided. During use, toothed portion of the straps engage toothed portions of associated pawls to provide for unidirectional travel of the straps through the base. For increased security, pawl locks are provided on the base. Each pawl lock has first and second retainers to engage the pawl lock on the base, where the first retainer is spaced from the second retainer along a length of the pawl lock. When the first retainer retains the pawl locks in the base, the pawls have sufficient freedom of movement to allow unidirectional movement of the straps through the base, and when the pawl locks are depressed such that the second retainer retains each pawl lock in its respective lock aperture, the pawl lock engages the pawl and presses the pawl against the strap, preventing further travel of the strap.

Restraining devices for restraining detainees are well known and have been available for many years. A well-known example of a restraining device is a pair of handcuffs. While traditional handcuffs serve the purpose of restraining an individual, they have a number of drawbacks. Conventional handcuffs are heavy, bulky to carry, expensive, require a key and are often inconvenient, particularly in multiple arrest situations. Because of these drawbacks, it has become more and more desirable to provide handcuffs which are lightweight, inexpensive and do not require a key. Moreover, it has become desirable to use disposable, one-time use handcuffs, particularly in multiple arrest situations.
Further, there has been a movement toward using one-time use handcuffs due to the increasing concern of the risk of spreading of disease, such as AIDS or Hepatitis, since restrained individuals who struggle violently often create open wounds which result in blood on the handcuffs. Disposable handcuff restraints are cut to be removed, thereby assuring that the restraints will not be reused. Disposing of the restraints prevent them from becoming a carrier for communicable diseases through contamination due to cuts or abrasions an individual may have received during the detainment.
One-time use handcuff restraints are available which address some of the problems of conventional key-operated handcuffs. For example, U.S. Pat. No. 5,802,675, which is incorporated by reference, discloses a double loop molded restraining device. Sawtooth-ribbed teeth are molded into the straps and an interlocking cover. The teeth engage as the strap is inserted, and do not allow the straps to be simply pulled out of the locking cover. However, to be of sufficient strength, such known restraints typically are made from a strong yet flexible material, such as nylon.
Nylons are moisture sensitive and absorb water (hydroscopic). As such, nylons may be characterized in two states, dry and conditioned. A conditioned nylon is one which has absorbed water. For example, at equilibrium, materials like nylon 6, nylon 6/6, and nylon 4/6 can hold approximately 1.5-2% of their weight in water. This value can be substantially higher if the nylon is immersed in water and is allowed to reach a saturation point.
The water content of nylons may be controlled to modify a nylon's properties of strength, flexibility, and brittleness. For example, nylon becomes increasingly flexible as moisture is absorbed. The strength and stiffness of the conditioned nylon is lower than dry nylon, but brittleness is also lowered, significantly improving damage resistance.
Nylon one-time use restraints may be moisture conditioned by pouring a predetermined amount of water into moisture-proof packaging for the restraints. During shipment and storage, the nylon restraints absorb the water and achieve a desired state of strength, flexibility, and impact resistance.
However, once nylon restraints are removed from their packaging, they may experience undesirable drying out and deconditioning. For example, it may be desirable to pre-fold the nylon restraints and carry them on one's person for quick and efficient use. This typically requires that they be removed from their package. Also, nylon restraints are typically used in environments where relative humidity and temperature are not controlled (such as outdoors), and may be carried in a prepared state for extended periods of time. For example, use outdoors in northern climates in the winter may dry the water out and decondition the nylon restraints. Heat may also adversely affect the conditioning. If a nylon handcuff restraint is deconditioned to close to its dry-as-molded state and is subjected to high loads, large flexures, or impacts, the nylon restraints may exhibit brittle failure. Pre-folded nylon handcuff restraints may be subject to all of these stresses.
A plastic which is flexible and not brittle in its dry-as-molded state, such as polyethylene, may be used for one-time restraints. Polyethylene is also less sensitive to heat and cold than nylon. These properties avoid the brittle failure disadvantage of nylon. However, flexible polyethylenes and other plastics are considerably softer than nylon. In particular, the plastics may be so soft as to allow a sufficiently strong individual to pull straps out, destroying the locking teeth in the process. In some designs, a load of as little as 70 pounds may damage the teeth and result in a failure of the handcuff restraint.


An improved electrode is disclosed for use in administering drug by means of iontophoresis, comprising a conductive element for receiving an electric current from a current source; a reticulated element having a plurality of reticulum for receiving an ionic drug solution for iontophoretic delivery, the reticulum being loaded or having applied thereto a hydrophilic polymer which is viscous when hydrated; and means for securing the reticulated element to the conductive element so that electric current will be distributed substantially uniformly through the reticulated element when hydrated and when current is delivered to the conductive element. The presently preferred embodiment utilizes open cell polyurethane foam as the reticulated element and high molecular weight polyethylene oxide as the hydrophilic polymer. The reticulum is further loaded with Tween 20, a surfactant, which serves to improve the rate of hydration. A reticulated element formed in accordance with the present invention is pliable and conformable both when in wet or dry state, making an electrode formed in accordance with the present invention susceptible of a wide variety of shapes and sizes and relatively easy to manufacture at reasonably low cost.

1. Technical Field
The present invention relates to iontophoretic electrodes, with particular emphasis on electrodes which are used to administer a drug by means of iontophoresis. Although the preferred embodiment is directed to an electrode packaged in dry form which is to be hydrated immediately prior to use, it is also possible to utilize the apparatus of the invention in connection with electrodes provided in a hydrated form.
2. Background Information
Iontophoresis is a method for delivering an ionic form of a drug through the skin in the presence of an electrical potential. It is typically performed by placing an electrode containing an ionic drug solution in contact with the skin at the location where drug is to be transported. A second electrode is placed on the skin near the first electrode, and voltage is applied sufficient to cause current to pass through the skin, thereby completing the electrical circuit between the electrodes. As current flows, the ionic drug molecules migrate through the skin under the influence of the second electrode. One advantage of iontophoresis is that it is a noninvasive means of administering drug, yet avoids many problems which are encountered in oral administration of drugs.
One of the most common uses of iontophoresis is to administer dexamethasone sodium phosphate for the local treatment of local inflammation, tendinitis, bursitis, arthritis, or carpal tunnel syndrome. Iontophoresis is also frequently used to administer lidocaine hydrochloride to serve as a local anesthetic.
In view of the significant clinical benefits of iontophoretic administration of drugs, much attention has been given to the use of iontophoresis as a method for administering other drugs, and it is anticipated that iontophoresis will develop as a method of choice in an increasing number of applications.
One general class of electrode designs involves the use of a conductive element associated with a compartment or pouch into which a drug solution is introduced. One wall of the pouch typically comprises a permeable barrier, which serves to contain the solution, but permits drug ions to pass therethrough. Examples of such electrodes can be seen in U.S. Pat. Nos. 4,250,878; 4,419,092; and 4,477,971.
Pouch-type designs suffer from several problems. For example, the use of a permeable barrier inhibits thorough and complete wetting of the skin lying thereunder, which results in areas of relatively high electrical resistance. The diffusion rate through the permeable membrane also has an undesirable inhibiting effect upon the rate of drug delivery in comparison to an electrode design wherein the drug is directly against the skin.
Another problem with the pouch designs is the need to guard against leakage of the drug solution from the pouch during use. This requires use of a sealed means for introducing drug solution into the pouch, which increases the cost of this type of electrode.
Pouch designs also suffer from a lack of conformability. This exacerbates the problem of uneven wetting of the skin and results in uneven delivery of drug. Lack of conformability also increases the incidence of skin irritation and burns during iontophoresis because it results in an uneven application of electrical current.
A second class of electrode designs involve the use of a conductive element associated with a gel material for containing ionized drug without the use of a pouch. Examples of such bioelectrodes are found in U.S. Pat. Nos. 4,383,529; 4,474,570; and 4,747,819. Typically, these gel-type electrodes incorporate ionized drug into the gel at the time of manufacture. This makes storage and shipping of the electrode more difficult, and shortens the shelf-life of the electrode because it must be used prior to unacceptable degradation of the drug. Attempts to hydrate the gels at the time of use were generally unsuccessful due to the long time required to obtain uniform hydration. Use prior to full and complete hydration leads to uneven current distribution which, as noted above, can result in skin inflammation or burns. As with pouch designs, the use of gel-type electrodes also fails to completely wet the skin lying thereunder resulting in the problems already discussed.
A third class of electrode design is disclosed in copending U.S. application Ser. No. 07/645,028, filed Jan. 23, 1991, entitled "Hydratable Bioelectrode", and U.S. Pat. No. 5,087,242, filed Jul. 21, 1989 and issued Feb. 11, 1992. The text of said copending application and issued patent is hereby incorporated by reference. This third type of electrode design generally utilizes a conductive element associated with a hydratable element. As described in the copending application and the issued patent, the hydratable element is typically formed of a stack of sheets of a dry crosslinked hydrogel, such as crosslinked polyethylene oxide (PEO).
Although a vast improvement over pouch designs and gel-type designs, the crosslinked hydrogel electrode designs still suffer from several significant disadvantages. For example, the dimensions of a hydratable element utilizing a crosslinked hydrogel design are limited because of the requirement for liquid to penetrate from the edges of adjacent sheets to the center thereof before hydration causes blocking; dimensions in excess of about 5 centimeters have been found to result in imperfect hydration, probably due to collapse of the hydrogel sheets upon hydration, thereby blocking further hydration interior of the blockage. Also, in dry form, the stack of sheets of crosslinked hydrogel is relatively stiff and essentially planar. Both of these factors place limitations upon the size, shape, and uses of the electrode.
Also, some manufacturing problems are encountered when preparing the stack of crosslinked hydrogel sheets. For example, the requirement to bind the stack of sheets together adds manufacturing steps and costs. Additionally, since the sides of adjacent sheets must remain open to entry of liquid at the time of hydration, limitations are placed upon the manner in which the hydratable element may be affixed to the conductive element.


Between electrodes (9) and (10) are formed a p.sup.+ substrate (2), an n.sup.- epitaxial layer (1) having a protruding portion (3), an n.sup.+ diffusion region (4) and p.sup.+ diffusion regions (13). Control electrodes (6) are formed on insulating films (5) on opposite sides of the protruding portion (3) and n.sup.+ diffusion region (4). The potential at the control electrodes (6) is increased or decreased with the potential at an electrode (10) increased relative to an electrode (9) to generate potential barrier or conductivity modulation in the n.sup.- epitaxial layer (1), whereby a semiconductor device turns off or on. Introduced holes are drawn through the p.sup.+ diffusion regions (13) when the semiconductor device turns off, to provide a small resistance and a short distance when the holes are drawn without changes in the area of the n.sup.+ diffusion region (4). This permits the semiconductor device to have small switching loss and high switching speed with a low ON-voltage.

1. Field of the Invention
The present invention relates to a semiconductor device operated by the voltage of a control electrode and more particularly to techniques for improving operating characteristics of the semiconductor device.
2. Description of the Background Art
FIG. 30 is a plan view of a conventional semiconductor device. FIG. 31 is a perspective cross-sectional view thereof taken along the line X--X of Fig. 30. For case of understanding of the cross-sectional structure, parts of control electrodes and the like are not illustrated in FIG. 31. Reference numeral 1 designates an n.sup.- epitaxial layer; 2 designates a p.sup.+ substrate; 3 designates a protruding portion formed on the surface of the n.sup.- epitaxial layer 1; 4 designates an n.sup.+ diffusion region formed on the upper surface of the protruding portion 3; 5 designates insulating films formed on the side faces of the protruding portion 3 and n.sup.+ diffusion region 4; 6 designates a pair of control electrodes formed on the insulating films 5 on opposite sides of the protruding portion 3 and n.sup.+ diffusion region 4; 7 designates a p.sup.+ diffusion region formed in the n.sup.- epitaxial layer 1 at the end of the n.sup.+ diffusion region 4; 8 designates an insulating film formed on part of the p.sup.+ diffusion region 7, part of the n.sup.+ diffusion region 4 and control electrodes 6; 9 designates an Al--Si electrode formed in contact with the diffusion regions 4 and 7 and isolated from the other portions by the insulating film 8; and 10 designates a metal electrode contacting the p.sup.+ substrate 2.
The operation of the conventional semiconductor device will be described below with reference to FIGS. 32 to 34. As the potential at the control electrodes 6 relative to the electrode 9 is decreased with the potential at the electrode 10 relative to the electrode 9 increased, depletion layers extending from the control electrodes 6 come into contact with each other to generate potential barrier in the protruding portion 3 of the n.sup.- epitaxial layer 1 which lies between the control electrodes 6 as shown in FIG. 32. This prevents electrons from flowing from the electrode 9 toward the electrode 10. Thus current is interrupted.
As the potential at the control electrodes 6 relative to the electrode 9 is increased, the potential barrier disappears and electrons 12 start flowing from the electrode 9 toward the electrode 10. Simultaneously, holes 11 are introduced from the p.sup.+ substrate 2 to cause conductivity modulation in the n.sup.- epitaxial layer 1. As shown in FIG. 33, the introduced holes 11 are joined to the electrons again in the n.sup.- epitaxial layer I or n.sup.+ diffusion region 4 or they are absorbed into the p.sup.+ diffusion region 7. Thus the semiconductor device turns on.
As the potential at the control electrodes 6 relative to the electrode 9 is decreased again, potential barrier is generated again in the protruding portion 3 between the control electrodes 6, so that electronic current tends to stop flowing from the electrode 9 toward the electrode 10. Simultaneously, the introduced holes 11 travel along the surface of the insulating layers 5 in such a manner that they accumulate on the surface thereof to be commutated into the p.sup.+ diffusion region 7, as shown in FIG. 34. Thus the semiconductor device turns off.
The conventional semiconductor device thus constructed has problems to be described below. As the area of the n.sup.+ diffusion region 4 is increased relative to the p.sup.+ diffusion region 7 for reduction in ON-voltage, it takes longer to commutate the holes 11 when the semiconductor device turns off, resulting in reduction in switching speed and increase in switching loss.
On the other hand, as the area of the n.sup.+ diffusion region 4 is decreased relative to the p.sup.+ diffusion region 7, the switching speed and switching loss are improved. However, this causes a large number of holes introduced when the semiconductor device is on to be commutate into the p.sup.+ diffusion region 7, so that the n.sup.- epitaxial layer 1 adjacent the n.sup.+ diffusion region 4 is not sufficiently subjected to the conductivity modulation, resulting in increase in ON-voltage.
The conventional semiconductor device is disadvantageous in that the ON-voltage is in traded-off relation to the switching speed and switching loss so that it is difficult to simultaneously improve both of them.

Method of fabricating a semiconductor device


A contacting device comprises a carrier device with a first surface, a plurality of first terminal regions on the first surface, at least one elastic elevation on the first surface, and a plurality of interconnects, each running from a respective of the first terminal regions to an upper side of the elastic elevation. The plurality of first terminal regions is configured so that signals of a tester device can be fed to the plurality of first terminal regions, the interconnects have first contact regions located at the upper side of the elastic elevation configured to be contacted electrically with corresponding second contact regions of an integrated circuit, and the first contact regions comprise first particles for roughening the surface of the first contact regions.

1. Field of the Invention
The present invention relates to a contacting device for the contacting of an integrated circuit, in particular of a chip or a wafer, with a tester device, a corresponding testing method and a corresponding production method.
Although it can be applied in principle to any integrated circuits or components, the present invention and the problem on which it is based are explained with reference to chips with integrated circuits using silicon technology.
2. Description of the Prior Art
The increasing production density of today's electronic circuits or electronic circuit units, also referred to as chips, is leading to increased requirements for testing. Before delivery, the electronic circuit units must be subjected to various tests. In a conventional way, the electronic circuit units accommodated in packages are inserted into special test sockets and thereby contacted at the package contacts. For the contacting of unpackaged chips, needle cards, which usually have resilient contact pins, are used.
During the contacting, the circuit units to be tested are subjected to various test conditions. For example, series of tests are conducted at an elevated temperature over a prolonged period of time, for example 120° C. for a time period of 24 hours. These series of tests are also referred to as "burn-in". Long test times can rapidly lead here to high costs of testing and to commercial disadvantages.
For the efficient contacting of the circuit units to be tested, it has been proposed to provide sockets into which the circuit units to be tested are introduced.
A major disadvantage of known methods for the contacting of electronic circuit units is that these circuit units have to be provided with a package and corresponding terminal contacts outside the package.
Conventional contacting devices cannot be used for circuit units to be tested without a package, i.e. so-called "bare chips". There is an increasing demand for provision of so-called multi-chip modules, i.e. various chips or circuit units are accommodated in a single module.
It is quite possible here for the individual circuit units to be supplied by different manufacturers. One important aspect in the delivery of circuit units without a package is that the circuit units must be inspected for defects just as carefully as the packaged circuit units.
Most widespread are chips with contact areas of aluminum. An electrical measurement of such unpackaged chips is currently carried out with needle adaptors. The needles perforate the thin oxide skin of the aluminum and lead to a good, low-impedance contact. Corresponding measuring devices are complex, expensive and unsuitable for a multi-hour burn-in. Published German patent application 103 24 450 A1 discloses an example of a known contacting device.

Contacting device, testing method and corresponding production method


A device for limiting an alternating electric current includes a least one passive semiconductor configuration and a protection circuit. The semiconductor configuration is configured such that when a forward voltage is applied thereto, a forward current flows through the semiconductor configuration. The forward current increases monotonously with the forward voltage up to a saturation current at an associated saturation voltage. At a forward voltage above the saturation voltage, the forward current is limited to a limiting current that is smaller than the saturation current. The semiconductor configuration is further configured such that when a reverse voltage is applied, a reverse current flows through the passive semiconductor configuration. The reverse current increases at a first rate monotonously with the reverse voltage up to a given reverse breakdown voltage and, when exceeding the reverse breakdown voltage, the reverse current rises at a second rate greater than the first rate due to a charge carrier breakdown. The protection circuit includes diodes for preventing the passive semiconductor configuration from being driven to the reverse breakdown voltage by a half wave of an alternating current in the reverse direction.

Field of the Invention
The invention relates to a device for limiting alternating electric currents.
In order to supply an electric load or device with an alternating electric current, the load is connected to a line branch of an electrical supply network via a switching device. In order to protect the load against excessively high currents, in particular in the event of a short circuit, switching devices having isolating switches which protect the branch and for which melting fuses are generally used, and switching devices having mechanical power switches with switching times of significantly more than one millisecond (1 ms) are employed in the field of low-voltage switching. If a plurality of loads are operated simultaneously in one line branch and if a short circuit occurs at just one of these loads, it is very advantageous if the loads which are not subject to the short circuit can continue to operate without disruption and only the load which is affected by the short circuit is switched off. For this purpose, current-limiting components ("limiters") are necessary directly upstream of each load. These components thus reliably limit the current of the prospective short circuit current to a predefined, noncritical overcurrent value within a time of significantly less than 1 ms and thus before the breaker (of the line protection switch) provided for the line branch is triggered.
In a current-limiting situation, such current limiters must be able to withstand, depending on the network, high voltages of usually up to 700 V and in some cases up to 1200 V which are present at the component. Since the power loss which occurs in the component is very high, it would be particularly advantageous if the current limiter also automatically reduced (intrinsically safe component) the current to values significantly below the predefined overcurrent value while additionally taking up voltage.
The only passive current limiter available on the market is a device which is described in the paper "Polyathylen-Stromwachter fur den Kurzschlu.beta.schutz" ("Polyethylene current monitor for short circuit protection") by T. Hansson, ABB Technik 4/92, pages 35-38 and which has the product name PROLIM. The device is based on a current-dependent conductivity of the grain boundaries of the material employed in this device. However, when the device for current limiting is used frequently, the current saturation value at which the current is limited may change.
Otherwise, in general only active current limiters, in other words current limiters which operate with a control or triggering and which detect the current and limit it through active control when a predefined maximum current value is exceeded, are employed. The German patent document DE 43 30 459 A and the corresponding German utility model DE 94 11 601 U disclose such an active, semiconductor-based current limiter. This active current-limiting semiconductor switch has a first semiconductor region of a predefined conduction type to which in each case one electrode is assigned on surfaces which face away from one another. In the first semiconductor region, further semiconductor regions of the opposite conduction type are disposed spaced apart from one another between the two electrodes. Between the individual further semiconductor regions, channel regions of the first semiconductor region are respectively formed, the channel regions being directed perpendicularly to the two surfaces of the first semiconductor region (vertical channels). A vertical flow of current between the two electrodes is conducted through these channel regions and is thus limited. In order to control the current flow between the two electrodes, a gate voltage, with which the resistance of the channel regions can be controlled, is applied to the oppositely doped semiconductor regions in the first semiconductor region.
German patent application DE 195 48 443 A1, which has been published after two of the priority dates claimed for the instant application and thus cannot be considered as prior art for the respective disclosure of the instant application, discloses a semiconductor configuration having a first semiconductor region of a given conduction type, a contact region which is disposed on a surface of the first semiconductor region, and a second semiconductor region which has the opposite conduction type from the first semiconductor region and is disposed within the first semiconductor region and underneath the contact region. The second semiconductor region extends further in all directions parallel to the surface of the first semiconductor region than the contact region so that in the first semiconductor region at least one channel region is formed. The channel region being bounded in the downward direction by the depletion zone of the p-n junction which is formed between the first semiconductor region and the second semiconductor region, and, in a conductive state, conducting an electric current from the contact region or to the contact region. The at least one channel region is thus disposed laterally in the first semiconductor region and thus has very good saturation properties. On a further surface of the first semiconductor region, which faces away from the aforementioned surface of the first semiconductor region, a further contact region is provided. An operating voltage for the semiconductor region can then be applied between this contact region and the contact region on the other surface of the first semiconductor region.
In one embodiment of the semiconductor configuration described in the published German patent application DE 195 48 443 A1, the channel region is limited, on a side lying opposite the second semiconductor region, by a depletion zone of a further p-n junction, which is formed with the first semiconductor region and at least a third semiconductor region of a conduction type opposite to that of the first semiconductor region. The third semiconductor region is assigned a control electrode for controlling the electrical resistance of the channel region by applying a control voltage. In a further embodiment, the channel region is limited, on a side lying opposite the second semiconductor region, by the depletion zone of at least one Schottky contact. In this embodiment also, a control voltage can be applied to the Schottky contact in order to control the electrical resistance of the channel region.

Device for limiting alternating electric currents, in particular in the event of a short circuit

SiCED Electronics Development GmbH & Co. KG


A method and apparatus for encoding or decoding data in accordance with an NB/(N+1)B block code, and a method for determining codebooks for use in such encoding or decoding. Some such methods select positive and negative codebooks that are complements of each other, including by eliminating all candidate code words having negative disparity and filtering the remaining candidate code words in automated fashion based on predetermined spectral properties to select a subset of the candidate code words as the code words of the positive codebook. Preferably, all but a small subset of the (N+1)-bit code words (determined by a primary mapping) can be decoded by simple logic circuitry, and the remaining code words (determined by a secondary mapping) can be decoded by other logic circuitry or table lookup.

The invention pertains to methods and apparatus for encoding data in accordance with an NB/(N+1)B block code for transmission and to methods and apparatus for decoding the encoded data. The invention is particularly useful in communication environments in which the spectrum of the transmitted signal is significantly constrained, e.g., in high-speed, wired data transmission systems which require the spectrum of the transmitted signal to be restricted to as a narrow a band of high frequencies as possible, and to be free of a DC component.
Throughout the disclosure, including in the claims, the notation xe2x80x9cnB/mBxe2x80x9d code (or xe2x80x9cn-bit-to-m-bitxe2x80x9d code) is used to denote a block code in which n-bit symbols (input words) are encoded as m-bit code words, where m greater than n. For example, in a class of well-known conventional block codes are 8B/10B codes in wich 8-bit input words are encoded as 10-bit code words.
Throughout the disclosure, including in the claims, the term xe2x80x9csymbolxe2x80x9d is used synonymously and interchangeably with the expression xe2x80x9cinput word.xe2x80x9d
Throughout the disclosure, including in the claims, the expression xe2x80x9ctable lookupxe2x80x9d denotes a mapping operation that is implemented in any manner (not necessarily by searching a ROM or CAM type memory for an output value in response to an input value). For example, table lookup can be implemented using a memory-based lookup table or a logic-based lookup table, as a complex logic function (that performs the equivalent of a memory-based table lookup), as a logic truth table/Karnaugh map, or in any other suitable manner.
A digital communication channel imposes restrictions on the nature of the data it can carry. For example, during serial data transmission (transmission of a signal indicative of a bit sequence), sufficient transitions must be present to enable accurate clock and data recovery at the receiver, the DC component of the transmitted signal should be eliminated to prevent baseline wander, and the pass band frequency range should be minimized to reduce design complexity. To meet these requirements, conventional high-speed serial communication often transmits data that have been encoded using a conventional 8B/ 10B block code (e.g., the conventional code, sometimes referred to as the xe2x80x9cIBMxe2x80x9d 8B/10B code, described in U.S. Pat. No. 4,486,739, issued on Dec. 4, 1984). The IBM 8B/10B block code is DC-free, guarantees 3 transitions per code word, and ensures that the maximum run without a transition is 4 bits. However, an 8B/10B block code provides low channel utilization (only 80% of the channel capacity is available for application use). Communication protocols layered above this channel code further reduce channel capacity for carrying useful data.
To encode data using a block code, a sequence of user data bits is encoded as a larger number of bits according to a predetermined table or function. The added bits of overhead preferably ensure a high transition density to facilitate clock/data recovery, and accomplish DC balancing to maintain running disparity near zero, which enables the use of AC-coupling. Since the code space is larger than the data space, a modest error detection capability is also afforded.
Various serial links for transmitting data and clock signals are well known. One conventional serial link, used primarily for high-speed transmission of video data from a host processor (e.g., a personal computer) to a monitor, is known as a transition minimized differential signaling interface (xe2x80x9cTMDSxe2x80x9d link). The characteristics of a TMDS link include the following:
1. video data are encoded using an 8B/10B block code and transmitted as encoded words (each 8-bit word of digital video data is converted to an encoded 10-bit word before transmission):
a. the encoding determines a set of xe2x80x9cin-bandxe2x80x9d words and a set of xe2x80x9cout-of-bandxe2x80x9d words (the encoder can generate only xe2x80x9cin-band xe2x80x9d words in response to video data, although it can generate xe2x80x9cout-of-bandxe2x80x9d words in response to control or sync signals. Each in-band word is an encoded word resulting from encoding of one input video data word. All words transmitted over the link that are not in-band words are xe2x80x9cout-of-bandxe2x80x9d words);
b. the encoding of video data is performed such that the in-band words are transition minimized (a sequence of in-band words has a reduced or minimized number of transitions);
c. the encoding of video data is performed such that the in-band words are DC balanced (the encoding prevents each transmitted voltage waveform that is employed to transmit a sequence of in-band words from deviating by more than a predetermined threshold value from a reference potential. Specifically, the tenth bit of each xe2x80x9cin-bandxe2x80x9d word indicates whether eight of the other nine bits thereof have been inverted during the encoding process to correct for an imbalance between running counts of ones and zeroes in the stream of previously encoded data bits);
2. the encoded video data and a video clock signal are transmitted as differential signals (the video clock and encoded video data are transmitted as differential signals over conductor pairs);
3. three conductor pairs are employed to transmit the encoded video, and a fourth conductor pair is employed to transmit the video clock signal; and
4. signal transmission occurs in one direction, from a transmitter (typically associated with a desktop or portable computer, or other host) to a receiver (typically an element of a monitor or other display device).
A use of the TMDS serial link is the xe2x80x9cDigital Visual Interfacexe2x80x9d interface (xe2x80x9cDVIxe2x80x9d link) adopted by the Digital Display Working Group. A DVI link can be implemented to include two TMDS links (which share a common conductor pair for transmitting a video clock signal) or one TMDS link, as well as additional control lines between the transmitter and receiver.
A typical DVI link includes a transmitter, a receiver, and a cable comprising conductors connected between the transmitter and receiver. The conductors include a conductor pair for transmitting serialized data over one channel (Channel 0) from an encoder (in the transmitter) to a decoder (in the receiver), a conductor pair for transmitting serialized data over another channel (Channel 1) from another encoder in the transmitter to another decoder in the receiver, a conductor pair for transmitting serialized data over another channel (Channel 2) from a third encoder in the transmitter to third decoder in the receiver, and a conductor pair for transmitting a video clock over a fourth channel (Channel C) from the transmitter to the receiver. The conductors also include wires for a Display Data Channel (xe2x80x9cDDCxe2x80x9d) channel (which can be used for bidirectional I2C communication between the transmitter and receiver), a Hot Plug Detect (HPD) line (on which a monitor associated with the receiver transmits a signal that enables a processor associated with the transmitter to identify the monitor""s presence), xe2x80x9cAnalogxe2x80x9d lines for analog video transmission from the transmitter to the receiver, and xe2x80x9cPowerxe2x80x9d lines for provision of power from the transmitter to the receiver.
Each encoder in the transmitter encodes the data to be transmitted over one of Channels 0, 1, and 2, and serializes the encoded bits to be transmitted over the relevant channel. Each encoder responds to a control signal (an active high binary control signal referred to as a xe2x80x9cdata enablexe2x80x9d or xe2x80x9cDExe2x80x9d signal) by selectively encoding either digital video words (in response to DE having a high value) or a control or synchronization signal pair (in response to DE having a low value). Each of the encoders receives a different pair of control or synchronization signals: a first encoder receives horizontal and vertical synchronization signals (HSYNC and VSYNC); a second encoder receives control bits CTL0 and CTL1; and a third encoder receives control bits CTL2 and CTL3. Thus, each encoder generates in-band words indicative of video data (in response to DE having a high value), the first encoder generates out-of-band words indicative of the values of HSYNC and VSYN having a low value), the second encoder generates out-of-band words indicative of the values of CTL0 and CTL1 (in response to DE having a low value), and the third encoder generates out-of-band words indicative of the values of CTL2 and CTL3 (in response to DE having a low value). In response to DE having a low value, each of the second and third encoders generates one of four specific out-of-band words indicative of the values 00, 01, 10, or 11, respectively, of control bits CTL0 and CTL1 (or CTL2 and CTL3).
Another serial link is the xe2x80x9cHigh Definition Multimedia Interfacexe2x80x9d interface (xe2x80x9cHDMIxe2x80x9d link) developed by Silicon Image, Inc., Matsushita Electric, Royal Philips Electronics, Sony Corporation, Thomson Multimedia, Toshiba Corporation, and Hitachi. It has been proposed to transmit encrypted video and audio data over an HDMI link.
Another serial link (sometimes referred to as a xe2x80x9cSATAxe2x80x9d link) complies with the standard known as Serial ATA, Revision 1.0, adopted on Aug. 29, 2001, by the Serial ATA Working Group, for communication between a host and storage device. A host can be coupled to each of one or more storage devices, with a SATA link between the host and each storage device.
Other serial links differ from TMDS links by encoding data as N-bit code words that are not 10-bit TMDS code words, or by transmitting encoded video over more than three or less than three conductor pairs, or in other ways.
The term xe2x80x9ctransmitterxe2x80x9d is used herein in a broad sense to denote any device capable of encoding data and transmitting the encoded data over a serial link (and optionally also performing additional functions, which can include encrypting the data to be transmitted and other operations related to encoding, transmission, or encryption of the data). The term xe2x80x9creceiverxe2x80x9d is used herein in a broad sense to denote any device capable of receiving and decoding data that has been transmitted over a serial link (and optionally also performing additional functions, which can include decrypting the received data and other operations related to decoding, reception, or decryption of the received data). For example, the term transmitter can denote a transceiver that performs the functions of a receiver as well as the functions of a transmitter. For another example, in a system including two transceivers which communicate via a serial link, each transceiver can be both a receiver and a transmitter.
The data transmitted between the transmitter and receiver of a serial link can, but need not, be transmitted differentially (over a pair of conductors). Also, although a TMDS link has four differential pairs (in the single pixel version), three for video data and the other for a video clock, other serial links include a different number of conductors or conductor pairs.
Typically, the primary data transmitted by a TMDS link are video data. What is often significant about this is that the video data are not continuous, and instead have blanking intervals. These blanking intervals provide an opportunity for auxiliary data to be transported, and they represent unused bandwidth. However, many serial links do not transmit data having blanking intervals, and thus do not encode input data (for transmission) in response to a data enable signal. For example, audio serial links would typically transmit continuous data.
The term xe2x80x9cstreamxe2x80x9d of data, as used herein, denotes that all the data are of the same type and are transmitted with the same clock frequency. The term xe2x80x9cchannel,xe2x80x9d as used herein, refers to a portion of a serial link that is employed to transmit data serially (e.g., a particular conductor or conductor pair between the transmitter and receiver over which the data are transmitted serially, and specific circuitry within the transmitter and/or receiver used for transmitting and/or recovery of the data) and to the technique employed to transmit the data over the link.
It is known to encode input words in accordance with an NB/(N+1)B block code, and to transmit the resulting (N+1)-bit code words over a serial link. For example, U.S. Pat. No. 6,198,413, issued on Mar. 6, 2001, teaches use of a 7B/8B block code with a 9B/10B block code, with concatenation of the resulting 8 and 10 bit code words to implement 16B/18B encoding. U.S. Pat. No. 6,198,413 suggests (at col. 10, line 51 to col. 11, line 22) generation of some of the code words by logic circuitry (e.g., circuitry that appends a zero or one to a 9-bit input word to generate a 10-bit code word), but that table lookup may need to be used to generate other ones of the code words where logic circuitry for doing so cannot readily be implemented. It also suggests (at col. 11, lines 25-30) use of two sets of logic circuitry for encoding (e.g., logic circuitry for appending a zero or one to some 9-bit input words to generate 10-bit code words, and other logic circuitry which inverts some bits of other 9-bit input words and performs some other logical operation on each resulting 9-bit word to generate a 10-bit code word). It also teaches (e.g., with reference to XOR gates 4008 and 4010 of FIG. 4) an encoding method in which two different codebooks are used to encode each input word of an input word sequence, and a code word is chosen from one codebook (rather than the other) to encode each input word such that the chosen code word will not increase running disparity (and will thus tend to promote DC balance) of a code word sequence indicative of the input word sequence.
However, U.S. Pat. No. 6,198,413 does not teach an automated, robust method for choosing an NB/(N+1)B code, or a method for choosing an NB/(N+1)B code so that table lookup is used only rarely (if ever) during encoding of an input word sequence.
In preferred embodiments, the invention is a method and apparatus for encoding N-bit input words using a block code to generate (n+1)bit code words. Preferably, xe2x80x9cNxe2x80x9d is an odd integer (e.g., N=7 or N=9). In some preferred embodiments, (N+M)-bit input words are encoded to generate (N+N+2)-bit code word, using a first block code to encode an N-bit fragment of each input word as an (N+1)-bit code word, using a second block code to encode the remaining M bits of the input word as an (M+1)-bit code word, and concatenating the (N+1)-bit code word with the (M+1)-bit code word. Preferably, xe2x80x9cNxe2x80x9d and xe2x80x9cMxe2x80x9d are odd integers.
Block coding in accordance with the invention can provide spectral properties similar to those provided by conventional 8B/10B coding while reducing the channel coding overhead (e.g., to about 10% for a 9B/10B code from about 20% for a conventional 8B/10B code). This provides greater channel capacity for application use, thereby increasing the effective bandwidth of the communication link. Alternatively, the savings from the reduced overhead is redeployed (e.g., by transmitting control bits and/or special characters with the encoded data) to create an enhanced physical and link layer that provides higher level communication protocol functionality (communication protocol functionality at at least one level higher than the link level).
To implement preferred embodiments of the invention, the N most desirable (N+1)-bit code words having disparity greater than or equal to zero (i.e., the N most desirable code words that have more ones than zeros, or an equal number of ones and zeros) are selected to determine a xe2x80x9cpositivexe2x80x9d codebook (each N-bit input word is mapped to one of the code words in the positive codebook). A xe2x80x9cnegativexe2x80x9d codebook, including the complement of each code word in the positive codebook, is also determined. Each code word in the negative codebook has disparity less than or equal to zero, and each of the N-bit input words is mapped to one of the code words in the negative codebook. The code words are chosen so that, for most input words, a simple systematic mapping to an (N+1)-bit code word in the positive codebook exists and can be implemented by simple logic circuitry (e.g., to force a transition with the added bit). During encoding, the other N-bit input words (typically only a small subset of the full set of N-bit symbols) can be replaced by code words of the positive codebook via table lookup. The resulting code words from the positive codebook are then replaced by their complements (members of the negative codebook) as necessary to maintain DC balancing.
When using positive and negative codebooks in which each code word has an even number of bits, code words of neutral disparity (disparity equal to zero) can occur in both codebooks. If each code word has an odd number of bits, each codebook would include only code words with strictly positive (or strictly negative) disparity. In the latter case, the codebooks would be forced to contain disjoint halves of the code space and the spectrum could not be deterministically controlled. Thus, in preferred implementations of NB/(N+1)B coding in accordance with the invention, N is an odd number. However, such codes do not have good affinity with 8-bit data that is typically used in computer systems. If this issue increases the implementation complexity beyond a reasonable measure, two such codes can be used together to form less dense code spaces that possess better alignment with 8-bit data. For example, 9B/10B and 7B/8B codes can be used together to form a 16B/ 18B code, by concatenating 8-bit and 10-bit code words generated in accordance with the 9B/10B and 7B/8B codes to generate 18-bit code words.
Preferred embodiments of the invention take advantage of the typical case that most of the N-bit input words exhibit the desired spectral properties by implementing a simple, systematic mapping of each such input word to an (N+1)-bit code word (preferably using simple logic circuitry). The input words that do not exhibit desired spectral properties are mapped to code words with more complex functions or via a simple table.
In preferred embodiments, the invention is a method for selecting positive and negative codebooks that are complements of each other that includes the following steps. Selection of the positive codebook begins by eliminating all candidate code words having negative disparity. The remaining candidate code words are then filtered, preferably in automated fashion (e.g., by a programmed computer) based on predetermined spectral properties to select a subset of the candidate code words that determines the positive codebook. For example, simple filters eliminate each of the candidate code words having transition density below a predetermined transition density, each of the candidate code words having disparity greater than a predetermined disparity, and each of the candidate code words having a transition-free run of length that exceeds a predetermined maximum run length. Spectral analysis of the code space can be used to rank the potential code words and select only those above a particular threshold for inclusion in the codebook. For example, code words with runs greater than 5, transition density less than 30%, or disparity greater than 4 can be eliminated. The code words of the positive codebook are then selected from the remaining candidate code words to determine a bijective (injective, in the sense that when f(x1)=f(x2), it is true that x1=x2, and positive codebook. For each input symbol, the code word in the negative codebook is then identified as the complement of the code word in the positive codebook for the input symbol.
In variations, the positive and negative codebooks are not strictly complements of each other. For example, in some embodiments, the code words of the negative codebook having nonzero disparity are complements of corresponding code words of the positive codebook, but the code words of the negative codebook that have zero disparity are identical to (they are not complements of) corresponding code words of the positive codebook.
In preferred embodiments, a mapping is defined from input words to a xe2x80x9cpositivexe2x80x9d codebook containing only code words of neutral or positive disparity, and the mapping of each code word of the positive codebook to a code word of a corresponding xe2x80x9cnegativexe2x80x9d codebook is determined simply by complementing the former code word to generate the latter code word. Alternatively, the mapping of each code word (having nonzero disparity) of the positive codebook to a code word of a corresponding xe2x80x9cnegativexe2x80x9d codebook is determined by complementing the former code word to generate the latter code word, and each code word (having zero disparity) of the positive codebook is identical to a corresponding code word of the xe2x80x9cnegativexe2x80x9d codebook. Ideally, for each codebook, a mapping function from the input words to the code words (of the codebook) is found that is bijective and simple to implement using logic circuitry. However, even if such an ideal mapping function cannot be found, a simple mapping function can typically be identified that covers a large subset of the input symbol space, and the remaining input symbols are handled as special cases (e.g., special input symbols for which encoding must be accomplished using look up tables).
Preferred embodiments in which most input words meet the desired spectral constraints employ a straightforward mapping that systematically concatenates a bit of predetermined value (e.g. a zero bit) with (e.g., prepends or appends the bit to) each input word to form a code word, or systematically inserts a bit of predetermined value (e.g. a zero bit) in a predetermined position among the bits of each input word to form a code word. Possibilities for such mapping functions include inserting a bit so that symbol disparity becomes more positive (and complementing the resulting code word if its disparity is negative) and inserting a bit so that symbol disparity approaches zero (complementing the resulting code word if its disparity is negative). Many other mappings are also possible. The selection of a mapping depends on its symbol coverage and implementation complexity. For small code spaces, the exemplary mappings set forth in this paragraph can provide coverage of roughly 80% of the input words, while requiring only simple logic circuitry to implement.
The input words for which a straightforward mapping (implementable by simple logic circuitry) fails will typically significantly violate the spectral constraints (e.g., they will have very low transition density). These symbols can be subjected to a secondary mapping technique that applies a more complex function. For example, the secondary mapping could perform alternate bit inversion for symbols with low transition density, complementing the resulting code word if its disparity is negative. The implementation cost of the secondary mapping must be weighed against the cost of simply handling all the unmapped symbols as special cases, using a simple implementation structure such as a lookup table.
When the secondary mapping is accomplished by table lookup, the mapping can be arbitrarily complex. This gives greater flexibility to the mapping process. For example, code words can be selected so as to minimize the magnification of bit errors in the encoded data stream.
In a class of embodiments, the invention is a communication system including two endpoints (e.g., a transmitter and receiver or two transceivers) and a serial link (having at least one channel) between the endpoints, at least one of the endpoints is configured to generate encoded data by encoding input words in accordance with a line code and to transmit the resulting code words over each of one or more channels of the link to the other endpoint, and the line code specifies an NB/(N+1)B block code for encoding the input words. Typically, the line code also specifies special characters that are distinguishable from bit sequences of the transmitted code words. Another aspect of the invention is an endpoint device (i.e., a transmitter, receiver, or transceiver) configured to generate encoded data in accordance with a line code (where the line code specifies an NB/(N+1)B block code for encoding input words, and typically also specifies special characters) and to transmit the encoded data over a serial link, and/or to receive and decode such encoded data after the encoded data have propagated over a serial link.
Other aspects of the invention are methods for generating encoded data in accordance with a line code (where the line code specifics an NB/(N+1)B block code for encoding input words, and typically also specifies special characters), methods for decoding such encoded data, and methods for determining a set of code words (e.g., positive and negative codebooks) for implementing such a block code.

Method and apparatus for encoding or decoding data in accordance with an NB/(N+1)B block code, and method for determining such a block code


A meat grinder wherein the meat discharging end of the barrel for the rotary feed screw is separably connected with a tubular member having an extension which is remote from the barrel and is provided with a lateral meat evacuating opening. A star-shaped meat tearing or ripping member is installed in the tubular member upstream of the evacuating opening and has a bearing for the rear end portion of a shaft the front end portion of which is connected to a transverse front end wall of the extension. The latter is surrounded by a tubular element which has a lateraly opening and is rotatable relative to the extension to move its opening to a position of greater lesser register or overlap with the opening of the extension and to thus vary the rate of discharge of meat from the tubular member. A disc-shaped baffle is mounted on the shaft adjacent the opening of the extension and is movable to any one of several different positions axially of the shaft. The rear end portion of the shaft is surrounded by a plastic sleeve which is installed upstream of the tearing member and further receives the front end of the shank of the feed screw in the barrel.

The invention relates to meat grinding machines in general, and more particularly to improvements in meat grinders of the type disclosed in commonly owned German Pat. No. 37 44 433.
The meat grinder which is disclosed in the German patent has a barrel for a feed screw which advances meat beyond the discharging end of the barrel and into a tubular member which is separably affixed to the discharging end of the barrel by a nut. The tubular member has an extension with a lateral meat evacuating opening flanked by serrated or otherwise roughened edge faces to rip or tear the pieces of meat on their way from the extension. The extension has an end wall which is remote from the barrel and serves to rotatably support one end of an elongated shaft the other end of which receives the front end of the rotary shank of the feed screw. The tubular member has internal protuberances serving to prevent rotation of pieces of meat which are forced to advance from the barrel toward and into the lateral evacuating opening of the extension. The feed screw can be rotated by hand or by a suitable motor.
An advantage of the patented meat grinder is that is does not sever the pieces of meat but merely tears the pieces on their way toward the evacuating opening. This preserves the fibers and enhances the consistency and appearance of the product which is discharged from the extension. Such meat grinders have been found to constitute substantial improvements over conventional meat grinders which are devoid of any means for tearing or ripping the pieces of meat on their way from the barrel toward and through the evacuating opening. Moreover, the patented meat grinder can be readily taken apart to afford access to all parts which require cleaning prior to storage as well as prior to actual use.

Meat grinder with meat tearing attachment


The invention is directed to a compound of formula I, as defined herein, or a pharmaceutically acceptable salt thereof; a pharmaceutical composition containing a compound of formula I, a method of treatment of a disorder or condition that may be treated by administration of the compound, the method comprising administering to a mammal, especially a human, in need of such treatment a compound of formula I as described above, and a method of treatment of a disorder or condition selected from the group consisting Human African Trypanosomiasis (HAT), Chagas Disease, Malaria, Leishmaniasis, and other infectious diseases transmitted to humans and animals by exposure to parasites, the method comprising administering to a human or mammal in need of such treatment a compound of formula I as described above.

The present invention relates to novel cycloalkyl-diamines, pharmaceutical compositions comprising such compounds and the use of such compounds in the treatment and prevention of Human African Trypanosomiasis (HAT), Chagas Disease, Leishmaniasis, Malaria and similar parasitic diseases in humans and animals.
Human African Trypanosomiasis (HAT) is a disease spread by trypanosoma brucei, a parasitic organism which is transmitted to humans primarily via bites from the tsetse fly. HAT is often referred to as "sleeping sickness" because of the symptoms that emerge in patients who have progressed to the advanced, or Stage 2, level of infection following exposure to the CNS by the parasite; this latter stage of the disease is typically fatal (Jacobs and Ding, Annual Reports in Medicinal Chemistry, (2010), 45:277-294; Rollo, in Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 12th Ed., (2011), 1419-1441).
The disease is found in two forms, depending on the causative parasite (Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense). T. b. gambiense is primarily found in central and western Africa and causes a chronic condition that can remain in a passive phase for months or years before symptoms emerge. T. b. rhodesiense is found in southern and eastern Africa; symptoms of infection generally emerge in a few weeks and are more virulent and faster developing than T. b. gambiense. Approximately one-half million inhabitants of sub-Saharan Africa are potentially infected each year by the hemolymphatic, Stage 1, form of HAT. Symptoms include fever, headaches, joint pain and itching, as well as severe swelling of lymph nodes; chronically HAT symptoms include anemia, endocrine, cardiac and kidney dysfunctions.
Nearly 10,000 deaths have been reported as recently as 2010 from neurological, or Stage 2, HAT (Simarro, International Journal of Health Geographics, (2010), 9:57). Symptoms for these patients are generally more severe, including confusion, reduced coordination and disruption of the sleep cycle, as well as progressive mental deterioration leading to coma and death. Damage as a result of Stage 2 HAT is irreversible.
During the past decade there has been a renewed interest in developing safer, more efficacious HAT drugs, with an increased recognition of the impact of this disease upon quality of life for patients and their society in general. In fact, little had been accomplished over the past three decades to identify and develop safer and more efficacious medications for HAT, particularly for patients suffering from the advanced stage of this disease. The drugs most commonly used are essentially antifungal compounds, acting directly on the invasive protozoa in the bloodstream; poor penetration of the blood-brain barrier (BBB) has limited the use of some of these drugs to treatment of the hemolymphatic first stage of HAT. The most commonly prescribed treatments include pentamidine, suramin, melarsoprol, eflornithine and the combination therapy NECT (nifurtimox plus eflornithine). However, a growing concern in recent years is the issue of cross-resistance to some of the currently available medications. This is especially the case with pentamidine and arsenicals like melarsoprol (see Koning, Trends in Parasitology, (2008), 24(8):345-349).
The organism responsible for HAT, Trypansoma brucei (T. brucei), is also related to other parasitic species which can cause severely debilitating symptoms in humans and animals. Chagas disease, for example, caused by the related parasite Trypanosoma cruzi, is prevalent in a number of South American countries, affecting as many as 10 million individuals. It has also been detected in cattle, causing financial hardship for ranches as well as individual herders. Fatalities from Chagas disease are estimated to be about 21,000 per year and usually involve cardiovascular damage leading to death for the most seriously infected patients. Leishmaniases, detected in several forms, are estimated to affect as many as two million people on four continents while malaria, spread by exposure to one or more Plasmodium organisms, continues to afflict humans throughout the world.
One of the most commonly used HAT treatments for Stage 1 exposure is pentamidine. This diamidine compound has been extensively studied with respect to structure-activity relative to the replacement of the 1,5-dioxopentyl portion of the molecule by a variety of aryl and heteroaryl rings (e.g., Tidwell (2006) Journal of Medicinal Chemistry, 49:5324). However, little has been done to enhance pentamidine's brain concentration, e.g., through the incorporation of functional groups associated with enhanced CNS-penetration, such as those found in the most effective antipsychotic and antidepressant drugs currently on the market. Thus, it is possible that new treatments which target the T. brucei parasite and HAT could demonstrate sufficient efficacy against these related parasitic organisms and would thus be of immense value as antiparasitic therapeutic agents (Silva (2007) Biochemical Pharmacology 73:1939-1946).


The present invention concerns a method of manufacturing a lens for motor vehicle lighting modules, the method being intended to generate on the output surface (104) of said lens (100) microstructures formed by level differences situated on said output surface (104), the method including the following steps of forming a meshing on the output surface of said lens such that each mesh has similar dimensions, and generating in each mesh a microstructure formed by an output surface level difference, each level difference having a profile that varies as a function of the position of the mesh on the output surface of the lens.

1. Field of the Invention
The invention relates to a method of manufacturing a motor vehicle optical module lens, notably intended to generate a cut-off line in the optical beam of satisfactory sharpness.
2. Description of the Related Art
It is known to provide the lighting modules of a motor vehicle with means for blocking the upper part of an optical beam generated by this module to prevent dazzling the drivers of oncoming vehicles or followed vehicles. Such means are typically masks in the focal plane of the lens of the elliptical module or reflecting surfaces known as beam folders.
Such lighting modules are typically lights such as position lights, headlights, fog lights, adaptive driving beams (ADB), motorway driving lights, and generally any lighting beams that feature a cut-off line.
The brightness of the generated beam then features a cut-off line, and this can prove to be a problem. In fact, the beam forms an area of high contrast between, on either side of the cut-off line, an illuminated part of the road and a part of the road that remains dark.
In this case, there is a risk of this area of contrast causing discomfort for the driver of the vehicle emitting the beam if the cut-off is too sharp. In fact, movements of the vehicle that modify its attitude relative to the ground as it travels sweep this area over the road, which accentuates the discomfort caused by the contrast.
To prevent this discomfort, which is particularly significant with lighting modules (also known as "headlights") that are elliptical and have smooth lenses, some regulations, such as those that apply in the United States of America, impose the transmission of a minimum optical intensity of the lighting beam above the cut-off line. Thus the discomfort caused by the cut-off line is limited in that this cut-off line is less sharp and more diffuse.
To obtain this reduction of the sharpness of the cut-off line, it is known to situate on the output surface of a lens microstructures forming asperities on this output surface so that rays transmitted by these microstructures are transmitted in directions passing above and below the cut-off line, the sharpness of which is thus reduced.
For example, patent application FR 2 925 656 discloses such a lens in which the microstructures take the form of hollows and bosses disposed on the output surface of the lens either randomly (frosting) or in the form of a relatively regular array.
The document FR 2 931 251 discloses an elliptical motor headlight module lens in which areas with an optical diffusion effect are formed on a surface of the lens and divided into a periodic array of individual cells with respective structural elements, which causes targeted diffusion of the light.
Moreover, it is apparent in other examples that the profile of the microstructures is sinusoidal. Although this profile is simple to manufacture, it nevertheless has the drawback of offsetting the position of the maximum contrast that characterizes the position of the cut-off relative to the rest of the beam, or even of generating a second cut-off line in the beam, which leads to ambiguity when carrying out adjustments that is a serious problem with respect to complying with statutory standards, the double cut-off moreover degrading the range of the beam.
What is needed therefore is an improved method of manufacturing a motor vehicle optical module lens.

Method of manufacturing a motor vehicle optical module lens


A power distribution grid for a facility, such as a data center, is located within the facility. The power distribution grid includes a plurality of power transport elements arranged in a grid pattern and nodes located at intersections of the grid pattern. Electrical loads are supplied power via respective nodes of the power distribution grid. Also, each node is supplied power from more than two transport elements, such that one or more transport elements can fail and electrical loads connected to a particular node associated with the failed transport elements continue to receive electrical power supplied to the particular node from at least two different transport elements.

Typically operators of large computing facilities, such as data centers, design the facilities to include power distribution systems with a radial branch distribution design that includes one or more main branches and lower level branches fanning out from the main branches. At any given moment in time, each main branch receives power from a single power source, though the main branches may be switched to receive power from a back-up source if a primary power source fails. Such power distribution systems may also include one or more back-up branches with associated lower level branches that are similarly designed according to a radial branch distribution design and that similarly receive power from a single power source at a time. For example, a computing facility may include large pieces of electrical equipment, such as transformers, switchgear, uninterruptible power supplies (UPSs), etc., that receive electrical power from a utility power source and feed one or more main branches of a radial branch distribution design. Lower level branches that fan out from respective ones of the main branches receive power from the respective main branches and supply the power to loads. In some computing facilities, an additional one or more back-up branch circuits may mirror a primary branch circuit. Additionally, cooling systems for such facilities are often laid out using a radial branch distribution design. In a similar manner as power systems, a cooling system for a computing facility may include a relatively large cooler, such as a mechanical chiller, and the large cooler may feed cooling water to a main header that then branches out to smaller branches and ultimately to cooling loads. Alternatively or additionally, an HVAC system of a computing facility may include a main air duct that branches off into smaller air ducts and ultimately to cooling loads.
Such radial branch power distribution systems and cooling systems may be designed for a pre-determined load and a pre-determined load distribution, and may be difficult to modify without significant costs. Also, such radial branch power distribution systems and cooling systems may be significantly impacted by single-point failures. For example, a single failure may cause an interruption in service and/or may render a system without a back-up.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words "include," "including," and "includes" mean including, but not limited to.