An improved imprint device is disclosed. It comprises a drive component, an imprinting object, and at least one mold, stacked together within a chamber, a fluid supplier is used for providing the solvent fluid into the chamber through a pipe. The solvent fluid will permeate the imprinting object, and the imprinting object will be plasticized at the temperature lower than the glass transition temperature. The drive component is used for driving the mold to the plasticized imprinting object, so that the pattern on the mold will be imprinted on the imprinting object. It is the advantage of the present invention to reduce the process temperature, prevent the pattern distortion, and save the process time. Furthermore, by using the fluid and a barrier film as a pressing medium, the pressure can be applied to the object and the mold uniformly, such that a large area imprint can be achieved.

The development of the Micro Electro Mechanical System (MEMS) was beginning on the year 1990, which integrates multiple areas technologies, including the mechanism, electronics, optoelectronics, material, control, and chemical. Accordingly, the MEMS can be applied to miniaturize the product, and further improve the performance, reliability, quality and value added of the product, as well as, reduce the manufacturing cost and power consumption, for being convenient with the manufacturing and human life.
The micro hot embossing process is one of the areas of the MEMS technology, used for replicating the micro structure. The size unit of the micro structure is around nm to μm, and is able to be used as component directly or applied on other process.
Regarding to the micro hot embossing process, a mold is placed with a top pressing plate, and a plastic material used for hot embossing is placed with a bottom pressing plate, wherein these two pressing plates are regarded as heating/cooling devices for heating and cooling the plastic material. Therefore, while the plastic material will be hot embossed, the top pressing plate and the bottom pressing plate will be heated to the temperature higher than the glass transition temperature (Tg) of the plastic material. In the meantime, a driver will drive the top pressing plate and/or the bottom pressing plate to press on the mold and the plastic material. Accordingly, since the temperature of the plastic material is higher than the Tg thereof, the plastic material will become mobile, and further be full of the cavity of the mold and plasticized. Thereafter, the top pressing plate and the bottom pressing plate will be cooled to the temperature that is lower than the Tg of the plastic material after a determined imprint period. As long as the plastic material has getting solidified, and then the mold will be removed for having the product.


A switch (10) utilizes an infrared detector (22) that can be operated by existing wireless television or stereo remote control transmitters. Output from a triac (14) of a switch (10) to a load (11) can be varied remotely. In addition, a variety of load (11) types and ratings can be controlled.

1. Field of the Invention
This invention relates to electrical switches, specifically to an improved remote control for an in-line switch.
2. Discussion of Prior Art
Originally in-line or series electrical switches connected between the power source and the load, switching what is considered the HOT wire in a single phase Alternating Current (AC) circuit, operated by manually moving the switch position to either ON or OFF. These standard electrical wall switches were commonly of a two-wire type. Once the series switch was in the ON position, an effective short-circuit was created in series between the source and the load. Only the states of ON or OFF were possible.
Dimmer circuits implemented varying the voltage output to the load. U.S. Pat. No. 3,746,923 to Spira et al. (1973) discloses an in-line light dimmer switch with no remote control. Physically touching the switch still has to occur to cause dimming, or ON or OFF operations. Also, these circuits were still considered to be effectively a short-circuit with small power potential across the switch when operating ON or dimming. The problem of deriving power from these circuits for control, once they were effectively appearing as a short-circuit, was unanswered. Furthermore, the advantage of wireless remote control for these two-wire, in-line switches was not appreciated.
U.S. Pat. No. 3,824,428 to Spira et al. (1974) and U.S. Pat. No. 3,927,345 to Licata et al. (1975) describe fluorescent lighting circuits with the control in parallel and not series with the load. No derived power source for control of an in-line switch, or remote operation is disclosed.
Thereafter, U.S. Pat. No. 5,239,205 to Hoffman et al. (1993) discloses a radio frequency (RF) remote controlled in-line light switch; however, this switch having a multitude of components is complex, expensive, and has only an ON or OFF position. It is not effective in varying the voltage output and thus dimming the light. Hoffman et al. is further restricted in that it limits the power handling capacity of the switch, and can only supply resistive loads such as incandescent lights. Another disadvantage of Hoffman et al. is that the receiver or detector in conjunction with a special, matching transmitter must be set to the same frequency or wavelength for operation.
The problem of a simple, effective, remote control for an in-line, two-wire switch remains unaddressed.
No in-line or series switch is described which derives power for control while not having the load limit the switch capacity. No series switch is disclosed which can, through wireless remote control, vary the voltage output to the load.
Finally, no switch is disclosed which does not have to have a matching wavelength signal between the transmitter and receiver for operation, or which does not have to interpret an actuating signal.

Infrared remote controlled in-line power switch


The present invention relates to the discovery in mammalian cells, particularly human cells, of novel S-phase kinase associated proteins, p19 and p45, referred to herein as "Skp". As described herein, these proteins are components of the tumor cell-specific cyclin A/CDK2 complex and function to facilitate DNA replication. Interference with p45 function in vivo prevented entry into S-phase in both normal and transformed cells. Binding data indicated that p45 and p19 associate with each other in a binary complex. Moreover, p45 is required for p19 binding to cyclin A/CDK2.

The division cycle of eukaryotic cells is regulated by a family of protein kinases known as the cyclin-dependent kinases (CDKs). The sequential activation of individual members of this family and their consequent phosphorylation of critical substrates promotes orderly progression through the cell cycle. In its simplest active form, a CDK consists of a catalytic subunit (the cyclin-dependent kinase) and a positive regulatory subunit known as a cyclin. In mammalian cells, the CDK family consists of at least seven members (Meyerson et al., (1992) EMBO J. 11:2909-2917; Xiong et al., (1992) Cell 71:505-514; Matsushime et al., (1992) Cell 71:323-334; Meyerson and Harlow, (1994) Mol. Cell Biol. 14:2077-2086; Fisher and Morgan, (1994) Cell 78:713-724). Combination with an equally diverse family of cyclins yields numerous cell cycle regulatory enzymes each with a potentially unique function. In mammals, more than one kinase subunit is implicated in cell-cycle control. For example, progression from G1 to S phase involves CdK4/cyclin E; S phase Cdk2/cyclin A; and M phase Cdc2/cyclin B (Nasmyth and Hunt, (1993) Nature 366:634-635).
The activity of CDKs is controlled by several mechanisms that include stimulatory and inhibitory phosphorylation events, and complex formation with other proteins. To become active, a CDKs require the association with its corresponding cyclin. Many cyclins either oscillate in abundance during the cell cycle or require the presence of growth factors for expression (see, for example, Nigg, (1993) Trends Cell Biol. 3:296; Sherr, (1993) Cell 73:1059-1065). For example, human CDK4 exclusively associates with the D-type cyclins (D1, D2, and D3) (Xiong et al., (1992) supra; Xiong et al., (1993a) Genes and Development 7:1572-1583; and Matsushime et al., (1991) Cell 65:701). The complexes formed by CDK4 and the D-type cyclins have been strongly implicated in the control of cell proliferation during the G1 phase (Motokura et al., (1993) Biochem. Biophys. Acta. 1155:63-78; Sherr, (1993) supra; Matsushimi et al., (1992) supra; and Kamb et al., (1994) Science 264:436-440). Once formed, cyclin/CDK complexes still require phosphorylation of a threonine residue (usually near amino acid 160) for activity (Solomon et al., (1993) EMBO J. 12:3133-3142; Fisher and Morgan, (1994) supra; Makela et al., (1994) Nature 371:254-257). Active enzymes can be further regulated by inhibitory phosphorylation (e.g. of Thr14 and Tyr15 in cdc2) (see Solomon, (1993) Curr. Opinion Cell Biol. 5:180-186; Dunphy, (1994) Trends Cell Biol. 4:202-207 for review) and by the binding of inhibitory proteins (e.g. p21 or p16) (reviewed in Hunter and Pines, (1994) Cell 79:573-582; Xiong et al., (1993b) Nature 366:701-704; Harper et al, (1993) Cell 75:805-816; Serrano et al., (1993) Nature 366:704-707).
Differences in the abilities of normal and transformed cells to proliferate had long predicted that alterations in the pathways that control cell cycle progression must accompany cellular transformation. Alteration in growth control pathways can translate into changes in the cell-cycle regulatory machinery, but the mechanisms by which this occurs are still poorly understood. This prompted a comparison of cyclin/CDK complexes present in normal fibroblasts to those present in their transformed derivatives (Xiong et al., (1993a) supra). In normal cells, each of the cyclin-dependent kinases exists in part in a quaternary complex consisting of a cyclin, a CDK, the proliferating cell nuclear antigen (PCNA) and the inhibitory protein p21 (Zhang et al., (1993) Mol. Biol. Cell 4:897-906). Quaternary complexes are lost from many transformed cells due to the absence of the tumor suppressor, p53, which directly controls the expression of p21 (Xiong et al., (1993a) supra; El-Deiry et al., (1993) Cell 75:817-825). In these transformed cells, p16 becomes the predominant partner of CDK4 and CDK6.
Cyclin A-associated enzymes have been established as key promoters of progression through the S-phase of the cell cycle (see Heichman and Roberts, (1994) Cell 79:557-562 for review). The expression of cyclin A and the activity of cyclin A/CDK2 kinase peaks during late G1 and S phase in both normal and transformed cells (Pines and Hunter, (1990) Nature 346:760-763). Furthermore, microinjection of antibodies to cyclin A or introduction of antisense cyclin A expression constructs can prevent DNA replication (Girard et al., (1991) Cell 67:1169-1179; Pagano et al., (1992) EMBO J.11:961-971). In some cell types, cyclin A has even been shown to localize to sites of ongoing DNA synthesis (Cardoso et al., (1993) Cell 74:979-992). Finally, ectopic expression of cyclin A was sufficient to allow adhesion independent DNA synthesis in normal rat kidney cells (Guadagno et al., (1993) Science 262:1572-1575).
Comparisons of cyclin kinase complexes in normal and transformed fibroblasts have identified a class of subunit rearrangements that specifically affected cyclin A/CDK2 complexes and replace the quaternary cyclin A/CDK2/p21/PCNA complexes found in normal cells (Xiong et al., (1993a) supra). The determination of the identities and biological functions of the subunits present in transformed cells that replace the quaternary cyclin A/CDK2/p21/PCNA complexes is highly desirable particularly in developing novel diagnostic and therapeutic applications to treat diseases characterized by deregulated cell growth and division.

Cyclin/CDK associated proteins, and uses related thereto


A method includes causing, by a processor, a graphical user interface (GUI) to be output by a display. The GUI includes a first user input field identifying a target key performance indicator (KPI) associated with a network. A second user input field identifying a KPI peak-usage frequency. A third user input field identifying a peak-usage relationship. The method also includes creating a first monitoring profile based on the target KPI for the KPI peak-usage frequency for the peak-usage relationship. Storing the first monitoring profile. Monitoring the target KPI for the KPI peak-usage frequency based on the first monitoring profile. Collecting target KPI data over a period defined by the KPI peak-usage frequency. Determining a peak-usage during the period defined by the KPI peak-usage frequency based on the collected target KPI data. Periodically reporting peak-usage data based on the first monitoring profile.

Network service providers (e.g., wireless, cellular, fiber, and the like) are continually challenged to deliver value and convenience to consumers by, for example, providing network services that are dependable and capable of being flexibly constructed, scalable, diverse, and economically operated. To provide such network services, service providers often track key performance indicators (KPIs) that are indicative of an operating state of the network.
A performance indicator or KPI is a type of performance measurement. KPIs allow for evaluation of the success of a particular activity. Often success is simply the repeated, periodic achievement of levels of an operational goal (e.g. zero defects, 10/10 customer satisfaction, and the like), and sometimes success is defined in terms of making progress toward strategic goals. Accordingly, choosing the right KPIs to monitor relies upon a good understanding of what is important to the organization or the user assigned to evaluate network performance. What is deemed important often depends on the organization or the user assigned to evaluate network performance measuring the performance. Assessments often lead to the identification of potential improvements, so performance indicators are routinely associated with performance improvement initiatives.

User-defined network congestion monitoring system


An adapter for attaching a fluid handling device to a catheter tubing includes a body with a proximal end, a distal end and a passageway therethrough. The body has a proximal end that has a fitting for attaching a fluid handling device. The distal end of the body includes an elongate receptacle with an inside surface that has least one engagement lug. There is an elongate resilient member disposed within the receptacle with a first end and a second end and a coaxial passage therethrough. The passage has an inside diameter to accept and form a releasable substantially fluid tight connection to a preselected catheter tube. The resilient member has a first conjugate engagement to the receptacle engagement lug at the first end and a second engagement at the second end. The adapter also has a latch member disposed over the receptacle to contain the resilient member that has a distal axial access port therein to receive the catheter tube into the resilient member passage. The latch member has an inside surface with at least one second engagement lug for engaging the second end engagement of the resilient member. The latch member is disposed for rotatable movement with respect to the body between an insertion position and a latched position. The rotation of the latch member with respect to the body rotationally displaces the first end of the resilient member with respect to the second end of the resilient member, thereby decreasing the inside diameter of the resilient member passage.

Catheters are elongate hollow tubes that are used to transmit fluids into or out of the body of a patient. Conventions followed for the devices described in this disclosure are that the term "proximal" is the direction away from the patient and toward the practitioner and the term "distal" refers to the direction toward the patient and away from the practitioner. There are many types of catheters currently used in medical practice. Some catheters are sufficiently strong and rigid to be introduced by themselves, urinary catheters are examples of this type of catheter. Another catheter type is positioned on the outside of a sharp introducer needle and slid down over the needle into the patient's body using the needle to make the penetration and provide a guide to placement of the catheter, many intravenous catheters are of this type. This disclosure is related to yet another type, a catheter that is introduced into the patient through the bore of a sharp introducer needle. Through-the-needle catheters are further separated into two types by the introducer needle. When a through-the-needle catheter has a fixed hub for attachment of a fluid handling device, the introducer needle cannot be slid off the proximal end of the catheter. Catheters with fixed hubs either are used with a splittable introducer needle or the needle must be left on the catheter. One important application of catheters in medical practice is the use of long flexible catheters to introduce medicaments, often anesthetic or analgesic formulations, into the spine of a patient. In this application, the long (50-75 cm) flexible catheter tubing (generally 19-21 gauge) is introduced into the patient's epidural space through the bore of an introducer needle.
These spinal anesthesia procedures are widely used in hospital practice, with the generic name of "an epidural." As an example, the use of an epidural anesthetic is described in obstetric practice. The epidural anesthetic procedure is useful in many other type of procedures. In a typical obstetric procedure, the epidural catheter is often placed early in the patient's labor with the patient lying on her side, then the patient is placed on her back with the knees elevated for the rest of the delivery. Since the patient is on her back, the introducer needle generally must be removed. Most epidural catheters do not have fixed hubs thus allowing the introducer needle to be slid proximally off of the catheter and removed. Once the needle is removed, it is necessary to mount an adapter onto the catheter so that a fluid handling device such as a syringe may be attached to the catheter. The adapter is then often secured with tape onto the patient's body. The Tuohy-Borst adapter was developed for this application. The Tuohy-Borst adapter allows a fluid handling device with a male luer fitting to be mounted onto a small diameter (generally 19-21 gauge: Nominal Outside Diameters for these 19 to 21 gauges are between about 1.10 mm [19 gauge] to about 0.8 mm [21 gauge]) flexible catheter tube. The original Tuohy-Borst adapter is formed from metal and is considered reusable. Other variants of the original Tuohy-Borst are now available formed from thermoplastics. The thermoplastic adapters are generally supplied sterile and are considered single-use and disposable. The Tuohy-Borst type adapters all depend in some degree on a threaded collar being screwed down around the catheter to compress a resilient plug contained in a body portion. The seal around the catheter is formed by compressing the tip of the resilient plug into a cavity around the catheter tube by screwing the collar down onto the plug. In most of these adapters, it is easy for a practitioner to inadvertently over-tighten the threaded collar and occlude the catheter lumen. Alternatively, if the collar is not tightened down sufficiently, the adapter may leak or may even come off of the catheter tube. Most of the available adapters are generally cylindrical, may include a releasable latch mechanism and require at least about one-half rotation of the collar portion with respect to the body portion to secure the adapter onto the catheter.
A widely used adapter, available from B. Braun, Bethlehem, Pa., has a collar and a body portion. The Braun adapter is capable of almost four complete rotations of the collar with respect to the body portion from the initial engagement of the threads. Additionally, if this collar of the B. Braun adapter is fully unthreaded from the body portion, it may detach and allow disassembly of the adapter. Another widely used adapter is the disposable successor to the reusable Tuohy-Borst available from Becton Dickinson and Company, Franklin Lakes, N.J. The collar of this successor adapter is fully seated on the body after only about two and one half rotations of the collar with respect to the body. Additionally, unlike the B. Braun adapter, the collar is retained on the body when completely unthreaded so that it cannot easily fall off Another available adapter, as disclosed in U.S. Pat. Nos. 5,053,015 and 5,226,898, has an external ratchet and includes small wings on both the body and the collar to facilitate the practitioners handling and, when the wings are aligned, provides some indication that the adapter is secured onto the tubing. When the adapter disclosed in the referenced patents is secured to the patient's body, the small wings may cause discomfort to the patient, and additionally, the adapter may sometimes be difficult for a gloved practitioner to handle.
Other than the catheter adapters disclosed in U.S. Pat. Nos. 5,053,015 and 5,226,898, substantially all of the available adapters do not provide the practitioner with much indication of the sufficiency of the degree of tightness of the collar with respect to the body, and it is not easily visually apparent if the collars are loosened so that the catheter tubing may be inserted into the adapter or if the collar is partially screwed down on the body, making it difficult to insert the catheter tube into the adapter body. Operating room time is expensive, and additionally, many procedures are conducted under time constraints that potentially have impact on the patient's well being. As a result, practitioners and their support staff make every effort to set up repeatable procedures with standardized placements of equipment to facilitate rapid implementation of procedures. If a practitioner attempts to put an adapter onto a catheter tube and has difficulty because the adapter is partially threaded, additional time is required. If a practitioner inadvertently over-tightens a collar of an adapter occluding the lumen, he may believe the catheter is clogged or kinked, remove it and have to repeat the placement. The repeat procedure not only subjects the patient to additional risk, but also significantly increases the time required. If an adapter is not sufficiently tightened, it may fall off or leak during an extended procedure, thereby resulting in improper patient medication. If a gloved practitioner has difficulty handling an adapter and drops it, there may be a time delay while another adapter is procured, and, in the case where the adapter is part of a procedure kit, another whole kit, with a significant cost increment, may need to be opened just to obtain another adapter.
If a catheter adapter that was easily handled by a gloved practitioner was available that provided the practitioner with a positive indication of its status, i.e., ready-to-receive a catheter tube or fully tightened; that could not be over-tightened; and required only about one quarter turn of the collar with respect to the body to be fully tightened, the art of catheter adapters would be advanced. Such a catheter adapter is disclosed below.

Adapter for mounting a fluid handling device on a catheter tubing


A hardware device architecture is described that improves security and flexibility in access to hardware device settings. A device management proxy service is digitally signed and granted access to device settings. Applications are then digitally provisioned by the proxy service and only validated signed requests from applications are permitted to change hardware device settings. Further granularity over hardware device settings is achieved through user accounts and groups established by the applications.

Recent years have seen a worldwide proliferation of electronic devices. Hardware manufacturers have been able to use standard operating systems such as, for example, popular smartphone operating systems like Google Android™, Apple iOS™, and Microsoft Windows Embedded 8 Handheld™ to create a new generation of products to enhance productivity and address various challenges in both the personal and commercial realm. Further, a robust software ecosystem has emerged around many of these devices to enhance their functionality and utility and to leverage the vast amount of information and services available from the Internet. The development of applications for these devices has undeniably been a significant factor in the market adoption of many of these devices. However, this development has also driven a need for enhanced security, as it is common nowadays for the hardware manufacturer, operating system provider, and application developer to be separate entities.
In the interest of increased security, the operating systems of many devices, now regularly restrict or eliminate the ability for applications to interact with hardware device settings. A current solution to this problem involves the elevation of the privileges of the application. However, the privilege rights offered by the operating systems are typically not specific enough to provide access only to the hardware settings that the application desires. The result is a different kind of security risk in that applications with elevated privileges have access to critical functionality that exceeds their needs.
Therefore, there is a need for further advances in hardware device architectures that allow for operating systems to provide applications with secure and specific access to hardware device settings.

Device management proxy for secure devices


Linesman type pliers (10) that have provisions for splicing wires together. The pliers (10) have a right body (20) with a first jaw (22) on one end, and a handle (24) on the other end, and a pivotal bore (26) in-between. The first jaw (22) includes a truncated, tapered recess half (28) that is configured to receive an outward-extending stop and the provisions for gripping wire. A left body (32) has a similar jaw, handle, bore and truncated tapered recess half, except with an outward-extending stop (38) on the inner end. A pivot pin (42) is jointly disposed within bores (26) and (36), thus forming a solid-joint that arcuately swivels the right body (20) and left body (32) together into parallel and adjacent alignment. When the jaws are closed a complete, annular, truncated tapered recess (44) is formed that allows insertion of a number of stripped wires that form a twisted splice when the pliers are manually rotated around the stationary wires.

Previously, many types of hand tools have been used to provide an effective means to twist wires into a splice.
The prior art listed below did not disclose patents that possess any of the novelty of the instant invention, however the following U.S. patents are considered related:
Patent NumberInventorIssue Date2,949,939MillaAug. 23, 19604,074,732WilkinsFeb. 21, 19784,995,128Montgomery et al.Feb. 26, 19915,711,182YangJan. 27, 19986,029,297FrenchFeb. 29, 2000
Milla in U.S. Pat. No. 2,949,939 teaches a manually-operated hand held wire splicer having a rectangular U-shaped frame with a flat base. The flat base houses a rotatable shaft with a slot and a series of bores configured to receive stripped wire ends. When a multi-conductor cable is held tightly in the frame and the shaft is rotated, the stripped wires are twisted together to form a splice.
Wilkins in U.S. Pat. No. 4,074,732 discloses a unitary multi-purpose tool that cuts, strips and twists wires together. The utility is for the preparation for installing insulated cap-type twist-on wire connectors and the like.
Montgomery et al. in U.S. Pat. No. 4,995,128 teaches a combination electrician's tool which incorporates a pair of pliers with a crescent wrench on one of the handles, and means to receive screwdriver tips and sockets on the other.
U.S. Pat. No. 5,711,182 issued to Yang is for a crimping tool capable of stripping wires, crimping wire connectors and cutting capscrews.
French in U.S. Pat. No. 6,029,297 discloses multi-purpose electrician pliers capable of wire stripping and wire splicing. The pliers also have the capability of being actuated so as to sandwich a length of a fish tape reel.
For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited U.S. Pat. No. 3,131,732 issued to Thurston.

Linesman pliers with wire splice twister


Provided are a system for analyzing a mask topography, which can reduce calculation time and increase calculation accuracy in consideration of a mask topography effect, and a method of forming an image using the system. The system and method simultaneously obtains a first electric field using a Kirchhoff method without considering a pitch formed on a mask and obtains a second electric field using an electromagnetic field analysis method considering the pitch, and then determines a third electric field on a pupil surface of a projection lens by combining the first electric field and the second electric field of forming an image, so as to calculate the image of an optical lithography system which includes an illumination system and a projection optical system and to which the projection lens belongs.

1. Field of the Invention
The present invention relates to a system and method for manufacturing a semiconductor device, and more particularly, to a system for analyzing a mask topography and a method of forming an image using the system.
2. Description of the Related Art
In photolithography, as a feature size on a mask becomes smaller than the wavelength of light used to illuminate the mask, the aspect ratio of the thickness of the mask to the feature size becomes higher. Accordingly, it is difficult to accurately simulate a topography of a pattern drawn on the mask (referred to as a "mask topography" hereinafter) using a conventional Kirchhoff method that assumes the mask to be a thin mask without topographic features.
The conventional Kirchhoff method will now be explained with reference to FIGS. 1A and 1B. Light transmitted through a space between light blocking layers 20 disposed on a substrate 10 had no phase change and had a higher transmittance or amplitude-like step function. An interval between the light blocking layers 20 on a 4× mask was 140 nm, and the wavelength of the light was 280 nm. In detail, FIG. 1A illustrates a plot of an amplitude (solid line) and a phase (dotted line) according to a horizontal position or distance in nanometers (nm). The amplitude was constantly high only in an area where the light blocking layers 20 were not formed, and there was no phase change according to the distance. Also, FIG. 1B illustrates an amplitude (arrow) and a phase according to frequency (f) on a pupil surface of a projection lens, wherein zero order light had an amplitude of a1 and ± first order light had an amplitude of a2 without any phase change.
To more accurately simulate a topography, an electromagnetic (EM) field analysis method has been proposed that calculates a transmittance and a phase of an electric field (E-field) on a mask surface considering a mask topography effect.
The conventional EM field analysis method will now be explained with reference to FIGS. 2A and 2B. Light transmitted through a space between light blocking layers 20 disposed on a substrate 10 has an amplitude or transmittance and a phase which are different from those of the conventional Kirchhoff method. Referring to an image 30 of FIG. 2A illustrating an amplitude and a phase and a graph 40 illustrating an amplitude (solid line) and a phase (dotted line) according to a horizontal position or distance, the light had an amplitude shaped like a distorted step function, and a variation in phase such that the phase below the light blocking layer 20 was changed.
Referring to FIG. 2B illustrating an amplitude (arrow) according to frequency (f) on a pupil surface of a projection lens, the amplitudes of zero order light and first order light were higher than their counterparts a1 and a2 of FIG. 1B, respectively. Also, the phase of the first order light was 10° or so. Briefly, a change in the amplitude and the phase of an E-field on a mask surface results in a change in the amplitude and the phase of an E-field of zero order light and first order light on a pupil surface of a projection lens. The change in the amplitude and the phase of the E-field on the pupil surface of the projection lens changes the contrast of an image on a wafer and affects focus tilt. Accordingly, the EM field analysis method can calculate the E-field on the mask surface and thus can accurately predict the image produced on the wafer.
When the E-field on the mask surface is calculated using the EM field analysis method and a mask pattern is a line and space (referred to as L/S) pattern, a calculation time is 1 minute or less. However, when the mask pattern is a complex two-dimensional (2D), pattern, a calculation time is increased exponentially. In particular, it is virtually impossible to calculate a complex 2D pattern in design for manufacturability (DFM) or optical proximity correction (OPC). Accordingly, attempts have been made to reduce a time required to calculate the amplitude or transmittance and the phase of an E-field on a mask surface by using an approximation model instead of the EM field analysis method.
Table 1 shows the characteristics of the conventional Kirchhoff method, the EM field analysis method, and the approximation model. Here, a domain decomposition method (DDM) and a boundary layer method were used as examples of the approximation model. The methods were compared in terms of whether they can calculate a mask topography effect, calculation time, and calculation accuracy.
TABLE 1Possibility ofcalculating maskCalculationCalculationMethodtopography effecttime (speed)accuracyKirchhoffImpossible1timePoorEM field analysisPossible10~100timeGoodDDMPossible2~5timesBetween goodand fairBoundary layerPossible1timeFair
Referring to Table 1, the EM field analysis method had the best calculation accuracy, but had the longest calculation time as, described above. The DDM method had a relatively good calculation accuracy, but had a long calculation time. In terms of the calculation time, the boundary layer method was the best for DFM and OPC. However, it was difficult to implement the boundary layer method and thus desired boundary layers could not be used for various patterns. Also, since the boundary layer method used only one predetermined boundary layer, the calculation accuracy was not high.

System for analyzing mask topography and method of forming image using the system


A LED device is provided. The LED comprises a frame, a housing, a LED chip and a protection component. The frame comprises a first lead frame and a second lead frame disposed along a first direction and isolated from each other. The housing partially covers the first and second lead frames, and has a receiving portion exposing parts of the surfaces of the first and second lead frames. The LED chip is disposed in the receiving portion on the exposed surface of the first lead frame, and electrically connected to the first and second lead frames. The protection component is disposed on a surface of the second lead frame that is covered by the housing and electrically connected to the first lead frame. None of the sides of a vertical projection of the protection component on the second lead frame is parallel or perpendicular to the first direction.

1. Technical Field
The invention relates in general to a light emitting diode (LED) device and a LED lamp using the same. More particularly, the invention relates to a LED device comprising a protection component disposed in a way that none of the sides thereof is parallel or perpendicular to an extending direction of the lead frame of the LED device, as well as a LED lamp using the same.
2. Description of the Related Art
In general, a light emitting diode (LED) may comprise a protection component. The protection component and the LED chip are connected in parallel so as to provide a current vent path when a reverse surge occurs.
If the protection component is disposed in the receiving portion of a LED device as the LED chip, the protection component may absorb a part of the light and deteriorate the luminous efficiency of the LED device. One approach for resolving this problem is embedding the protection component in the housing. With such disposition, the light emitted from the LED chip will not reach the protection component, so that the protection component will not absorb the light and deteriorate the luminous efficiency of the LED device. In the manufacturing process of such a LED device, the protection component is typically disposed on a frame, the housing embedding the protection component then is formed by way of plastic injection or the like.
In a conventional LED device, the protection component is disposed with a side parallel to a side of the frame. However, with such arrangement, the plastic material ejected at a high speed and high temperature may collide with the protection component and damage the conductive adhesive bonding the protection component on the frame, and further make the protection component fail. In addition, since the flow of the plastic material is resisted by the protection component, the yield rate of modeling LED device products will decrease.


Disclosed is a recording sheet which consists essentially of a substrate and, in contact with the substrate, a monoammonium compound of the formula: ##STR1## wherein R is an alkyl group, X is selected from the group consisting of fluoride, chloride, bromide, iodide, and astatide, and R', R", and R"' are each independently selected from the group consisting of alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, arylalkyl groups, and substituted arylalkyl groups, wherein R, R', R" and R"' are either the same as or different from each other; and mixtures thereof; an optional binder component; and an optional filler component.

The present invention is directed to recording sheets, such as transparency materials, filled plastics, papers, and the like. More specifically, the present invention is directed to recording sheets particularly suitable for use in ink jet printing processes. One embodiment of the present invention is directed to a recording sheet which consists essentially of a substrate and, in contact with the substrate, a monoammonium compound of the formula: ##STR2## wherein R is an alkyl group, X is selected from the group consisting of fluoride, chloride, bromide, iodide, and astatide, and R', R", and R"' are each independently selected from the group consisting of alkyl groups, substituted alkyl groups, aryl groups, substituted aryl groups, arylalkyl groups, and substituted arylalkyl groups; and mixtures thereof; an optional binder component; and an optional filler component.
Recording sheets suitable for use in ink jet printing are known. For example, U.S. Pat. No. 4,740,420 (Akutsu et al.) discloses a recording medium for ink jet printing comprising a support material containing at least in the surface portion thereof a water soluble metal salt with the ion valence of the metal thereof being 2 to 4 and a cationic organic material. The cationic organic materials include salts of alkylamines, quaternary ammonium salts, polyamines, and basic latexes. Specific examples of the salts of alkylamines include decylammonium acetate, undecylammonium acetate, dodecylammonium acetate, tridecylammonium acetate, tetradecylammonium acetate, pentadecylammonium acetate, hexadecylammonium acetate, heptadecylammonium acetate, octadecylammonium acetate, nonadecylammonium acetate, eicosylammonium acetate, decylammonium chloride, undecylammonium chloride, dodecylammonium chloride, tridecylammonium chloride, tetradecylammonium chloride, pentadecylammonium chloride, hexadecylammonium chloride, heptadecylammonium chloride, octadecylammonium chloride, nonadecylammonium chloride, and eicosylammonium chloride. Specific examples of the quaternary ammonium salts include lauryltrimethylammonium bromide, lauryltrimethylammonium chloride, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, octaisoquinolinium bromide, octaisoquinolinium chloride, hexadecyltrimethylammonium bromide, and hexadecyltrimethylammonium chloride. Specific examples of polyamines include polyamide polyamine, polyoxyethylene alkylamine, polyethylamine epichlorohydrin, polydimethylaminoethyl methacrylate, and polyalkylammonium. Specific examples of basic latexes include polyamine latex and alkylammonium latex.
U.S. Pat. No. 4,576,867 (Miyamoto) discloses an ink jet recording paper with improved water resistance and sunlight fastness of the image formed on the paper wherein the recording paper has attached to its surface a cationic resin of the formula ##STR3## wherein R.sub.1, R.sub.2, and R.sub.3 represent alkyl groups, m represents a number of 1 to 7, and n represents a number of 2 to 20, and Y represents an acid residue.
U.S. Pat. No. 4,446,174 (Maekawa et al.) discloses an ink jet recording method for producing a recorded image on an image receiving sheet with a jet of aqueous ink, wherein an ink jet is projected onto an image receiving sheet comprising a surface layer containing a pigment, and wherein the surface layer is capable of absorbing a coloring component in the aqueous ink.
U.S. Pat. No. 4,830,911 (Kojima et al.) discloses a recording sheet for ink jet printers which gives an image by the use of an aqueous ink containing a water-soluble dye, coated or impregnated with either of or a mixture of two kinds of water soluble polymers, one whose polymeric unit is alkylquaternaryammonium (meth)acrylate and the other whose polymer unit is alkylquaternaryammonium (meth)acrylamide, wherein the water soluble polymers contain not less than 50 mol percent of a monomer represented by the formula ##STR4## where R represents hydrogen or methyl group, n is an interger from 1 to 3 inclusive, R.sub.1, R.sub.2, and R.sub.3 represent hydrogen or the same or different aliphatic alkyl group with 1 to 4 carbon atoms, X represents an anion such as a halogen ion, sulfate ion, alkyl sulfate ion, alkyl sulfonate ion, aryl sulfonate ion, and acetate ion, and Y represents oxygen or imino group.
U.S. Pat. No. 4,554,181 (Cousin et al.) discloses an ink jet recording sheet having a recording surface which includes a combination of a water soluble polyvalent metal salt and a cationic polymer, the polymer having cationic groups which are available in the recording surface for insolubilizing an anionic dye.
U.S. Pat. No. 4,877,680 (Sakaki et al.) discloses a recording medium comprising a substrate and a nonporous ink receiving layer. The ink receiving layer contains a water-insoluble polymer containing a cationic resin. The recording medium may be employed for recording by attaching droplets of a recording liquid thereon.
European Patent Publication 0 439 363 A1, published Jul. 31, 1991, corresponding to copending application U.S. Ser. No. 07/469,985, filed Jan. 25, 1990, the disclosure of which is totally incorporated herein by reference, discloses a paper which comprises a supporting substrate with a coating comprising (a) a desizing component selected from the group consisting of (1) hydrophilic poly(dialkylsiloxanes); (2) poly(alkylene glycol); (3)poly(propylene oxide)-poly(ethylene oxide) copolymers; (4) fatty ester modified compounds of phosphate, sorbitan, glycerol, poly(ethylene glycol), sulfosuccinic acid, sulfonic acid and alkyl amine; (5) poly(oxyalkylene) modified compounds of sorbitan esters, fatty amines, alkanol amides, castor oil, fatty acids and fatty alcohols; (6) quaternary alkosulfate compounds; (7) fatty imidazolines; and mixtures thereof, and (b) a hydrophilic binder polymer. The binder polymer may be a quaternary ammonium copolymer such as Mirapol WT, Mirapol AD-1, Mirapol AZ-1, Mirapol A-15, Mirapol-9, Merquat-100, or Merquat-550, available from Miranol Incorporated.
Copending application U.S. Ser. No. 07/861,670, filed Apr. 1, 1992, the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate and coating consisting essentially of (1) quaternary ammonium polymers selected from the group consisting of (a) polymers of Formula I ##STR5## wherein n is an integer of from 1 to about 200, R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, p is an integer of from 1 to about 10, q is an integer of from 1 to about 10, X is an anion, and Y.sub.1 is selected from the group consisting of --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --(CH.sub.2).sub.k --, wherein k is an integer of from about 2 to about 10, and --CH.sub.2 CH(OH)CH.sub.2 --; (b) polymers of Formula II ##STR6## wherein n is an integer of from 1 to about 200, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, m is an integer of from 0 to about 40, r is an integer of from 1 to about 10, s is an integer of from 1 to about 10, X is an anion, and Y.sub.2 is selected from the group consisting of --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --(CH.sub.2).sub.k --, wherein k is an integer of from about 2 to about 10, and --CH.sub.2 CH(OH)CH.sub.2 --; (c) copolymers of Formula III ##STR7## wherein a and b are each integers wherein the sum of a+b is from about 2 to about 200, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are each independently selected from the group consisting of alkyl groups, hydroxyalkyl groups, and polyoxyalkylene groups, p is an integer of from 1 to about 10, q is an integer of from 1 to about 10, X is an anion, and Y.sub.1 and Y.sub.2 are each independently selected from the group consisting of --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 OCH.sub.2 CH.sub.2 --, --(CH.sub.2).sub.k --, wherein k is an integer of from about 2 to about 10, and --CH.sub.2 CH(OH)CH.sub.2 --; (d) mixtures of polymers of Formula I and polymers of Formula II; (e) mixtures of polymers of Formula I and copolymers of Formula III; (f) mixtures of polymers of Formula II and copolymers of Formula III; and (g) mixture of polymers of Formula I, polymers of Formula II, and copolymers of Formula III; (2) an optional binder polymer; and (3) an optional filler.
Copending application U.S. Ser. No. 07/861,668, filed Apr. 1, 1992, the disclosure of which is totally incorporated herein by reference, discloses a recording sheet which comprises a substrate; a first coating in contact with the substrate which comprises a crosslinking agent selected from the group consisting of hexamethoxymethyl melamine, methylated melamine-formaldehyde, methylated urea-formaldehyde, cationic urea-formaldehyde, cationic polyamine-epichlorohydrin, glyoxal-urea resin, poly (aziridine), poly (acrylamide), poly (N,N-dimethyl acrylamide), acrylamideacrylic acid copolymer, poly (2-acrylamido-2-methyl propane sulfonic acid), poly (N,N-dimethyl-3,5-dimethylene piperidinium chloride), poly (methylene-guanidine) hydrochloride, poly (ethylene imine) poly (ethylene imine) epichlorohydrin, poly (ethylene imine) ethoxylated, glutaraldehyde, and mixtures thereof; a catalyst; and a polymeric material capable of being crosslinked by the crosslinking agent and selected from the group consisting of polysaccharides having at least one hydroxy group, polysaccharides having at least one carboxy group, polysaccharides having at least one sulfate group, polysaccharides having at least one amine or amino group, polysaccharide gums, poly (alkylene oxides), vinyl polymers, and mixtures thereof; and a second coating in contact with the first coating which comprises a binder and a material selected from the group consisting of fatty imidazolines, ethosulfate quaternary compounds, dialkyl dimethyl methosulfate quaternary compounds, alkoxylated di-fatty quaternary compounds, amine oxides, amine ethoxylates, imidazoline quaternary compounds, alkyl benzyl dimethyl quaternary compounds, poly (epiamines), and mixtures thereof.
While known compositions and processes are suitable for their intended purposes, a need remains for improved recording sheets. In addition, there is a need for improved recording sheets suitable for use in ink jet printing processes. Further, a need remains for recording sheets for ink jet printing with a high degree of waterfastness. Additionally, there is a need for paper recording sheets for ink jet printing with reduced showthrough of the images on the side of the paper opposite to that printed. There is also a need for recording sheets for ink jet printing with enhanced optical density.

Recording sheets containing monoammonium compounds


Systems for detecting when a person exhibits a smile with therapeutic benefits including a facial expression detection device and a system processor. The facial expression detection device is configured to acquire facial expression data. The system processor is in data communication with the facial expression detection device and is configured to execute stored computer executable system instructions. The computer executable system instructions include the steps of receiving facial expression parameter data establishing target facial expression criteria, receiving current facial expression data from the facial expression detection device, comparing the current facial expression data to the target facial expression criteria of the facial expression parameter data, and identifying whether the current facial expression data satisfies the target facial expression criteria. The target facial expression criteria define a smile with therapeutic benefits.

Smiling is known to non-verbally communicate emotions, like happiness and joy, and other messages, such as approval between people. Lesser known is the fact that smiling can provide health benefits, both to the person observing another smiling and to the person smiling. This document will focus on the therapeutic health benefits from smiling to the person who is smiling.
Genuine smiling, often called a Duchenne smile, is a particular manner of smiling that has distinct health benefits. A genuine smile improves mood, reduces blood pressure, reduces stress, reduces pain, strengthens the immune system, strengthens relationships, increases attractiveness, and improves longevity. A genuine smile is characterized by activating muscles near the eyes and cheeks in contrast to a fake or perfunctory smile that merely involves shaping the lips.
Conventional facial recognition systems are capable of detecting certain expressions on a person's face, but are not designed to detect genuine smiles. Further, existing facial recognition systems do not include features to train people how to execute a genuine smile. Conventional facial recognition systems also lack features to encourage people to execute a genuine smile with a given frequency, for a given amount of time, and/or in response to a physiological trigger.
Thus, there exists a need for smile detection systems that improve upon and advance the design of known facial recognition systems. Examples of new and useful smile detection systems relevant to the needs existing in the field are discussed below.


A system for determining a position of an element in memory comprising a memory queue with a plurality of separate entries and propagate and generate logic in communication with the memory queue such that the propagate and generate logic is operable to inspect each the separate entry in the memory queue and to output one or more vectors indicating the position of the element in the memory queue.

Microprocessors often include circular buffers, which are a type of memory queue that may be used to store, e.g., memory accesses or instructions. The function of finding the first element of a certain type in the circular buffer may currently be implemented through ripple logic. Ripple logic starts at the first entry in the circular queue and determines if the entry is the desired element. If the entry is not the desired element, the circuitry sends a signal down to the next entry in the circular queue to indicate that the element has not been found. Circuitry associated with the next entry would then check that entry for the element. The process is repeated through each of the entries until the circuitry finds the desired value.
In current ripple designs, the gate delay through the circuit is directly proportional to the queue modulo (i.e., the size of the queue). Thus, a 64-entry queue would require twice the gate delay as a 32-entry queue. Such linearly increasing gate delay may be a disadvantage for processors with larger queues.

System for determining the position of an element in memory

Hewlett-Packard Development Company, L.P.


A light-sensitive composition comprises a light-sensitive compound, an alkali soluble resin and a fluorine-containing surfactant. The surfactant is a copolymer of a (poyoxyalkylene)acrylate or (polyoxyalkylene)methacrylate with an acrylate or methacrylate having a fluorine-containing aliphatic group. The copolymer has a weight average molecular weight of 1000 to 6000 and contains the acrylate or methacrylate in an amount of 10 to 25% by weight. The fluorine-containing aliphatic group has 6 to 20 carbon atoms and 30% or more by weight of fluorine atoms.

In manufacturing a light-sensitive planographic printing plate, for example, a light-sensitive material is dissolved in a suitable solvent, then coated and dried on a support. And as a measure to improve the coatability, a fluorine-containing surfactant is added to a solution dissolving a light-sensitive composition. Japanese Pat. O.P.I. Pub. Nos. 40249/1982 and 178242/1987, for example, describe that a uniform coating thickness can be obtained, without unevenness in coating, by coating and drying a light-sensitive coating solution to which a fluorine-containing surfactant is added in advance.
Japanese Pat. O.P.I. Pub. Nos. 135004/1979, 170950/1987 and 226143/1987, for example, describe that use of a light-sensitive composition containing an acrylic polymer surfactant bearing a fluorine containing aliphatic fluorinealiphatic group gives a uniform coating thickness, or improves the coatability of a light-sensitive coating solution.
Though this technique gives a good coatability, it cannot provide a light-sensitive composition having an adequate storage stability, because the solvent-solubility of the light-sensitive composition is so poor that gelation occurs after coating, and in a heavy case, precipitates are formed in a light-sensitive coating solution.
In addition, though conventional fluorine-containing surfactants can improve the coatability, they have a disadvantage of lowering the image visibility on light exposure.

Light-sensitive composition comprising a fluorine copolymer surfactant


A bit-driving apparatus is provided between a handle and a bit. The bit-driving apparatus includes a hollow shaft and a bit receiver. The hollow shaft includes a first section for connection with the handle and a second section. The bit receiver includes a first space for receiving the second section of the hollow shaft and a second space for receiving the bit. The hollow shaft drives the bit receiver through a driver. At least one connector connects the internal wall of the first space of the bit receiver with the periphery of the second section of the hollow shaft.

Referring to FIG. 10, a conventional selective one-way bit-driving apparatus 70 is provided between a handle 72 and a bit 74. The selective one-way bit-driving apparatus 70 includes a hollow shaft 76 and a bit receiver 78. The hollow shaft 76 includes a first section for connection with the handle 72 and a second section. The bit receiver 78 includes a first space for receiving the second section of the hollow shaft 76 and a second space for receiving the bit 74. The hollow shaft 76 drives the bit receiver 78 in selective one of two directions through two selective one-way drivers 80. A detent 82 is installed on the second section of the hollow shaft 76. A switch 84 in the form of a ring is provided around the first section of the hollow shaft 76. The switch 84 includes two recesses 86 in an internal face in order to receive the selective one-way drivers 88. Moreover, the switch 84 includes, in the internal face, three recesses 88, a selective one of which receives the detent 82 in order to keep the switch 84 in a selective one of three positions on the second section of the hollow shaft 76. A bolt 90 is driven into a central hole in the bit receiver 78 through a tunnel of the hollow shaft 76 so as to connect the hollow shaft 76 with the bit receiver 78. The bolt 90 is inadequate in holding the hollow shaft 76 to the bit receiver 78. The bolt 90 may be twisted and broken so as to leave a portion of the bolt 90 in the central hole of the bit receiver 78 that renders the bit receiver 78 useless. The first space of the bit receiver 78 is isolated from the tunnel of the hollow shaft 76 so that the selective one-way bit-driving apparatus 70 cannot be used with a bit 74 with two operative ends since that bit 74 requires a long tunnel.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.


A system, method and device for controlling security of a beacon. The system includes a beacon device configured to broadcast a beacon identifier, and change the beacon identifier to another beacon identifier and to broadcast the other beacon identifier when a request to change the beacon identifier is received. The control device is configured to map and store the beacon identifier and service information and provide the service information to a terminal device that has received the beacon identifier and has accessed the control device. The control device also provides information on the other beacon identifier to replace the beacon identifier, and utilize the other beacon identifier to retrieve the service information for preventing an unauthorized user from changing information and enhance information security.

This section is intended to merely provide background for embodiments of the present invention and is not considered prior art in the claims.
With the development of mobile communication networks and the advance in terminal specifications, mobile communication terminals, such as a smart phone, have evolved into total information provision devices or total entertainment equipment beyond just simple communication devices.
Such mobile communication terminals have a function for performing short-range wireless communication, such as near field communication (NFC) or Bluetooth, in addition to a communication function through mobile communication networks.
NFC has a short communication distance and requires a separate wireless communication chip. However, Bluetooth has a relatively long communication distance and most terminals have a Bluetooth communication function equipped therein. Thus, various communication services are being developed using Bluetooth.
Further, service solutions for providing a variety of information to mobile communication terminals possessed by users are being developed using a beacon that utilizes Bluetooth communication. In this case, a mobile communication terminal receives a corresponding beacon identifier from a beacon and uses the beacon identifier to acquire a variety of information.
In this case, any unauthorized user may make the mobile communication terminal receive information that is set by the unauthorized user by acquiring the beacon identifier without permission and mapping the beacon identifier and any information desired by the unauthorized user. Accordingly, a method for preventing this is needed.

System and method for controlling security of beacon and control device thereof


A method and apparatus for verifiably providing key recovery information to one or more trustees in a cryptographic communication system having a sender and a receiver Each communicating party has its own Diffie-Hellman key pair comprising a secret value and corresponding public value, as does each trustee The sender non-interactively generates from its own secret value and the public value held by the receiver a first shared Diffie-Hellman key pair comprising a first shared secret value, shared with the receiver but not with any trustee, and a corresponding public value. For each trustee, the sender then non-interactively generates an additional shared secret value, shared with the receiver and the trustee, from the first shared secret value and the public value corresponding to the secret value held by the trustee. The sender uses the additional shared secret value to encrypt recovery information for each trustee, which is transmitted to the receiver along with the encrypted message. Each trustee can decrypt its recovery information by regenerating its additional shared secret value from its own secret value and the public value of the first shared Diffie-Hellman key pair. The receiver can verify the correctness of the recovery information for each trustee by decrypting the information using the additional shared secret value for that trustee, without having to recreate the recovery information or perform computationally expensive public key operations.

1. Field of the Invention
This invention relates to a cryptographic key recovery system and, more particularly, to a method and apparatus for verifying the correctness of key recovery information within a cryptographic key recovery system.
2. Description of the Related Art
Data encryption systems are well known in the data processing art. In general, such systems operate by performing an encryption operation on a plaintext input block, using an encryption key, to produce a ciphertext output block. The receiver of an encrypted message performs a corresponding decryption operation, using a decryption key, to recover the plaintext block.
Encryption systems fall into two general categories. Symmetric (or private key) encryption systems such as the Data Encryption Standard (DES) system use the same secret key for both encrypting and decrypting messages. In the DES system, a key having 56 independently specifiable bits is used to convert 64-bit plaintext blocks to ciphertext blocks, or vice versa.
Asymmetric (or public key) encryption systems, on the other hand, use different keys that are not feasibly derivable from one another for encryption and decryption. A person wishing to receive messages generates a pair of corresponding encryption and decryption keys. The encryption key is made public, while the corresponding decryption key is kept secret. Anyone wishing to communicate with the receiver may encrypt a message using the receiver's public key. Only the receiver may decrypt the message, however, since only he has the private key. Perhaps the best-known asymmetric encryption system is the RSA encryption system, named after its originators Rivest, Shamir and Adleman.
Asymmetric encryption systems are generally more computationally intensive than symmetric encryption systems, but have the advantage that they do not require a secure channel for the transmission of encryption keys. For this reason, asymmetric encryption systems are often used for the one-time transport of highly sensitive data such as symmetric encryption keys.
Data encryption systems of all types have attracted the attention of government intelligence agencies and law enforcement agencies, since the same cryptographic strength that prevents decryption by unauthorized third parties also prevents decryption by intelligence or law enforcement officials having a legitimate reason for wanting to access the plaintext data. Because of such concerns, governments have either prohibited the use or export of strong encryption systems or have conditioned their approval on the use of weakened keys that are susceptible to key-exhaustion attacks (i.e., systematically testing all possible keys until the right one is found). Such weak encryption systems have the obvious disadvantage that they are just as vulnerable to unauthorized third parties as they are to authorized government officials.
Various cryptographic key recovery systems have recently been proposed as a compromise between the demands of communicating parties for privacy in electronic communications and the demands of law enforcement agencies for access to such communications when necessary to uncover crimes or threats to national security. Generally, in such key recovery systems, all or part of the key used by the communicating parties is made available to one or more key recovery agents, either by actually giving key portions to the key recovery agents (in which case the key portions are said to be "escrowed") or by providing sufficient information in the communication itself (as by encrypting the key portions) to allow the key recovery agents to regenerate the key portions. Key recovery agents would reveal the escrowed or regenerated key portions to a requesting law enforcement agent only upon presentation of proper evidence of authority, such as a court order authorizing the interception. The use of multiple key recovery agents, all of which must cooperate to recover the key, minimizes the possibility that a law enforcement agent can improperly recover a key by using a corrupt key recovery agent.
Key recovery systems serve the communicants' interest in privacy, since their encryption system retains its full strength against third parties and does not have to be weakened to comply with domestic restrictions on encryption or to meet export requirements. At the same, key recovery systems serve the legitimate needs of law enforcement by permitting the interception of encrypted communications in circumstances where unencrypted communications have previously been intercepted (as where a court order has been obtained).
In addition to serving the needs of law enforcement, key recovery systems find application in purely private contexts. Thus, organizations may be concerned about employees using strong encryption of crucial data where keys are not recoverable. Loss of keys may result in loss of important data.
An important aspect of key recovery systems is the method used to ensure that correct recovery information is provided. If the recovery information provided is not correct, either through unintentional error, or deliberate attempt to conceal, the functionality of the key recovery system can be thwarted. Validation can be provided in several ways, including direct checking by the participants, checking by the trustees, and checking by the recovery entity. Correctness can also be ensured by redundant calculation and disclosure of the recovery information by more than one of the communicating parties.
Verification methods have several desirable properties. The verification method should not require communication with parties external to the given communication, either at installation, or during message creation and transmission. The method of verification should ensure correctness even if some (but not all) of the communicating parties deliberately attempt to provide incorrect recovery information. The verification method should minimize the required computations, and transmission overhead associated with the verification.
Key recovery systems of various types are described in D. E. Denning and D. K. Branstad, "A Taxonomy for Key Escrow Encryption Systems", Communications of the ACM, vol. 39, no. 3, Mar. 1996, pp. 34-40, incorporated herein by reference. Several specific key recovery systems are noted below.
Micali et al. U.S. Pat. Nos. 5,276,737 ("Micali I") and 5,315,658 ("Micali II") describe a "fair" public key cryptosystem in which the private key of a public/private key pair is broken into "shares" that are given to "trustees". The "breaking" is done in such a manner that: (1) the shares of all trustees (or a predetermined quorum) are required to reconstruct the key; and (2) each trustee can individually verify the correctness of his share. When all the trustees have certified the correctness of their share, the user's public key (corresponding to the escrowed private key) is certified by a key management center. Upon a predetermined requests the trustees provide their shares to a law enforcement agent or other recovering entity, who then reconstructs the private key from the shares and, with the private key, is able to monitor communications to the user. In this key recovery system, verification is done by the key management center and the trustees. This method of verification is undesirable, in that it requires prior communications with the trustees and key management center.
In another key recovery system, described in U.S. Pat. No. 5,557,346 to Lipner et al., the sender splits a session key into first and second session key portions by setting the first session key portion equal to a random number and setting the second session key portion equal to the XOR product of the random number and the session key. The sender creates a law enforcement access field (LEAF) by encrypting the respective session key portions with the public encryption keys of first and second key recovery agents and concatenating the two encryption products. The sender also creates a LEAF verification string (LVS) by concatenating the original session key portions and encrypts this using the session key to form an encrypted LEAF verification string (ELVS). Finally, the sender transmits an encrypted message, together with the LEAF and ELVS, to the receiver.
Before decrypting the encrypted message, the receiver regenerates the LEAF to verify that the sender has created a proper LEAF that would actually permit recovery of the session key through the key recovery agents. This is done by decrypting the ELVS to obtain the session key portions and then encrypting the respective session key portions with the public encryption keys of first and second key recovery agents. If the receiver succeeds in regenerating the transmitted LEAF in this manner, it concludes that the LEAF is genuine and proceeds to decrypt the message. Otherwise, it concludes that the LEAF is corrupt and does not proceed with the decryption step.
In this key recovery system, the verification of key recovery information is done by the receiver, which does avoid communication with the trustees or key management center. It does however require several public key encryption and decryption operations for every communication session, which is expensive in terms of computation and message size.
The copending application of R. Gennaro et al., Ser. No. 08/725,102, a filed Oct. 2, 1996, and entitled "Two-Phase Cryptographic Key Recovery System" (attorney docket P0996104), describes an alternative method of key recovery called SKR, which permits a portion of the key recovery information to be generated once and then used for multiple encrypted data communications sessions and encrypted file applications. In particular, the mentioned portion of the key recovery information that is generated just once is the portion that requires public key encryption operations. Hence, SKR provides a way of reducing the costly public key encryption operations required of other key recovery methods.
The Gennaro et al. application also describes a verification mode in which the communicating parties Alice and Bob each produce SKR recovery blocks independently, without checking the other's so produced blocks. In this mode, if at least one side is correctly configured, all required recovery information is correctly produced. In addition, both Alice and Bob are free to include any optional recovery fields without causing a false invalidation of what the other sent. One limitation of this verification mode, however, is that it cannot be used in non-interactive communications.
The SKR method of key recovery and verification described in the Gennaro et al. application is computationally efficient, as it provides for extensive caching of the recovery information, and requires no explicit verification. Its principal disadvantages are: (1) that it does not provide verification for non-interactive communications without requiring the receiver to perform public key operations; and (2) that it requires the transmission of additional secret information to Bob to allow him to perform verification, increasing the size of required communications.
The recent paper of E. Verheule B. -J. Koops and H. C. A. van Tilborg entitled "Binding Cryptography, A Fraud-Detectible Alternative to Key-Escrow Proposals" (1996), published at http://cwis.kub.nl/.sup..about. frw/people/koops/binding.htm, and the paper of E. Verheul and H. C. A. van Tilborg entitled "Binding the ElGamal Encryption Scheme" (1996), published at http://cwis.kub.nl/.sup..about. frw/people/koops/bindtech.htm, present an alternative for validation of key recovery information. The papers describe a method in which a disinterested observer can verify that something encrypted under a receiver's public key is the same as something encrypted under an agent's public key. If the "something" is a session key or part of a session key, as is the case in key recovery fields, the observer can use this to validate the encrypted recovery data. Unlike the previous methods of verification, however, this method provides no way for the observer to verify that the encrypted fields actually contain correct information; instead, the observer only verifies that the encryptions contain the same secret.
Still other methods of verifiably providing key recovery use variants of the Diffie-Hellman (DH) key agreement protocol. By way of background, the Diffie-Hellman key agreement protocol is a procedure whereby two parties may establish a shared secret value (from which a symmetric encryption key may be derived) by exchanging only public values over a communications channel. The protocol was originally described at page 649 of W. Diffie and M. E. Hellman, "New Directions in Cryptography", IEEE Transactions on Information Theory, vol. IT-22, no. 6, Nov. 1976, pp. 644-654, and in U.S. Pat. No. 4,200,770, both incorporated herein by reference.
In the two-party interactive form of the protocol, each party generates (e.g., pseudorandomly) a secret value x which it keeps to itself. Each party then generates a public value EQU y=g.sup.x mod p
where x is the secret value of that party, p is a prime modulus and g is a generator over the Galois field GF(p) consisting of the set of integers {0, 1, 2, . . . p-1}, and transmits the public value to the other party. Thereafter, each party generates a shared secret value EQU z=y.sup.x mod p
where x is its own secret value, y is the public value received from the other party, and p is defined as above. By virtue of the properties of modulo arithmetic, the shared secret values z generated by the two parties are the same.
The parties may derive a symmetric encryption key directly from the shared secret value z, as by extracting the required number of bits. Alternatively, the parties may perform a further operation on the shared secret value such as concatenating it with another value and hashing the concatenation result, as described in the copending application of S. M. Matyas et al., Ser. No. 08/736,774, filed Oct. 25, 1996, entitled "Method and Apparatus for Establishing an Authenticated Shared Secret Value Between a Pair of Users", incorporated herein by reference.
The security of this procedure relies on the apparent fact that, for appropriate choices of p and g, it is computationally infeasible to obtain either the secret values x or the shared value z from the public values y exchanged between the parties. Although exponentiation over a finite field was used in the above example, in general any suitable functions y(x) and z(x, y) may be used that have the commutative property
z(x1, y(x2))=z(x2, y(x1))
for any x1 and x2 and have the noninvertibility property mentioned above.
One such method of verifiably providing key recovery based on establishing a shared common Diffie-Hellman key was proposed by Dorothy E. Denning in "To Tap or Not to Tap", Communications of the ACM, vol. 36, no. 3, Mar. 1993, pp. 26-33. In this paper she proposed an escrow system based on a three-party variation of Diffie-Hellman described in section 22.1 of B. Schneier, Applied Cryptography (2d ed. 1996) as well as in the original Diffie et al. (1976) article cited above. In this method of key recovery, the verification of the recovery information can be inherent in the receiver's decryption of the information encrypted under the shared session key k.
The system proposed by Denning works as follows: Let Alice be the sender, Bob be the receiver, and Ted the trustee in order around the three-party circle. Let their respective secret parts be x, y, and z. In the first round, Alice sends to Bob g.sup.x mod p, Bob sends to Ted g.sup.y mod p, and Ted sends to Alice g.sup.z mod p. In the second round, Alice sends to Bob g.sup.zx mod p, Bob sends to Ted g.sup.xy mod p, and Ted sends to Alice g.sup.yz mod p. From these values, everyone can calculate k=g.sup.xyz. If Alice sends something to Bob encrypted with k, Bob knows that Ted can calculate k and decrypt it also. (If Alice is dishonest, and does not want Ted to be able to calculate k correctly she could send an incorrect value of g.sup.zx mod p to Bob, and Bob would be unable to detect the error. This can be fixed by having Bob verify this value directly with Ted as an additional exchange of messages after the second round.)
This method has the advantage of being able to send encrypted recovery information to both Bob and Ted with a single encrypted field, thus reducing the size of data and the number of calculations. However, this method has the disadvantage of requiring communication with the trustee prior to transmission of the message to the receiver.
In a paper entitled "Alternatives to RSA Using Diffie-Hellman with DSS" (1996), published at http://www.cylink.com/products/security/rsa/rsa-dss2.htm, Cylink Corporation proposed a method similar to Denning's, but not requiring interactive communication with the trustee. Using the same example, let Alice be the senders Bob be the receiver, and Ted be the trustee, and let their respective secret parts be x, y, and z.
Prior to any communication, Ted calculates a shared Diffie-Hellman key v with Alice based on Alice's public key (g.sup.x mod p), and his private key Z, as follows: EQU u=g.sup.xz mod p EQU v=g.sup.u mod p
Ted publishes v as a public key shared between Alice and him. For communication with Bob, Alice can calculate a key k as:
k=g.sup.yv mod p
Both Bob and Ted can calculate k, so if Alice sends something to Bob encrypted with k, she knows that Ted can also read it. In addition, Bob can verify this escrow, as he knows that Ted published the shared key v, and Ted can therefore calculate k. However, the disadvantage of this method is that it requires Alice to obtain a published shared key from Ted prior to communication with Bob.

Method and apparatus for verifiably providing key recovery information in a cryptographic system

International Business Machines Corporation


An apparatus and method for preventing the peeling of electroplated metal from a wafer, is disclosed. The apparatus includes a seed layer detector system having a light source and a reflectivity detector. According to the method, the light source emits a beam of light onto a wafer and the reflectivity detector receives the light reflected from the wafer. The reflectivity of the wafer surface is measured to determine the presence or absence of a seed layer on the wafer, as well as whether the seed layer has a minimum thickness for optimum electroplating of a metal onto the seed layer.

When a copper layer is deposited on a substrate, such as by electrochemical plating, the copper layer must be deposited on a metal seed layer such as copper which is deposited on the substrate prior to the copper ECP process. As shown in FIG. 1, during an ECP process a contact ring 14 is positioned in close proximity to a wafer 10 as copper is electroplated onto a seed layer 12 which was previously deposited on the wafer 10 prior to the ECP process. The contact ring 14 serves as an electrical conduit between the wafer 10 and an electroplating current source (not shown) and facilitates monitoring of the electrical resistance of the wafer 10 during the ECP process. The electrical resistance of the wafer 10 reveals the presence or absence of the seed layer 12 on the wafer 10.
In the event that the seed layer 12 is insufficiently thin or absent from the wafer 10, copper electroplated onto the wafer 10 has a tendency to peel off of the wafer 10 into the electroplating bath. This contaminates the wafer 10 and subsequent wafers 10 processed in the ECP bath solution. Therefore, the electrical resistance of the wafer 10, as measured through the contact ring 12, serves as a precautionary tool to verify that the seed layer 12 is present on the wafer 10 and of sufficient thickness upon commencement of the ECP process.
However, electrical conductivity of the wafer 10 has been found to be an unreliable indicator as to the thickness characteristics of the seed layer 12 on the wafer 10. Furthermore, seed layer verification can only take place after the wafer 10 is immersed in the electroplating bath solution and electroplating has begun. Therefore, a novel apparatus and method is needed to verify the presence or absence of a seed layer and the thickness of a seed layer on a wafer prior to commencement of an ECP process.

Apparatus and method for preventing copper peeling in ECP

Taiwan Semiconductor Manufacturing Co., Ltd.


A mechanism structure for decoupling prong and socket type electrical connections, particularly for circuit board cards and their connections to receptacle-connectors in chassis-like housings. In one embodiment, the decoupling structure comprises a plate, a rotatable rod supported by the plate, an actuating lever attached to one end of the rod, and a cam attached along the rod. In application, the lever is pushed or pulled causing the cam to apply a force separating the circuit board from the receptacle connection so as to reduce or avoid torsional forces when disconnecting the board from the receptacle.

A circuit board card may comprise a single printed circuit board(PC) or multiple circuit boards connected in a module form sometimes having multiple output connectors. Insertion and removal of a circuit board card from a connecting socket is typically done by hand after these components have been manually connected. For a circuit board card housing one or several circuit boards, the edge of the card may contain a different connector for each board. The connector for each card comprises a plurality of conductive sockets or prongs. These sockets or prongs are mated to corresponding sockets or prongs in a receptacle which is usually mounted to a chassis-like housing. This receptacle which sometimes is called an edge connector, provides mechanical support for the circuit board card. The term "circuit board card" is used herein to refer to both individual circuit boards of the plug-in variety and modules of multiple circuit boards having one or more connectors mounted along an end portion.
In the past, to insert and remove a circuit board card, it has been necessary to firmly grip the circuit boards themselves. For insertion, sufficient force is applied to assure a reliable connection. Removal also required a firm grip and the application of pulling forces. However, the pulling forces often included a rotational force from having to free the card from the receptacle. Such removal might result in an undesirable twisting movement relative to the plane of the card. Such torsional forces can bend the circuit board cards and produce mechanical damage such as cracking on the corners or edges of a circuit board or card. This can lead to costly repair to the cards, the connector receptacle, and even the chassis-like housing in which these components are located.
Further, it is becoming more common for circuit board and card assemblies to be located in small physical spaces where insufficient room exists to generate the leverage necessary to properly decouple the card from the receptacle without causing damage to these components and to the system in which they are located.
Until now, the torsional problems and resulting wear or damage to components have been tolerated as necessary inescapable penalties associated with standard connector designs.
There is now provided a decoupling mechanism for reducing damage caused to cards comprising single or multiple circuit boards--and the respective connector-receptacles to which they are mated.
According to the invention, a prong and socket electrical connection is disengaged by positioning a rotatable arm about an interface of the prong and the socket, and the arm is rotated against the prong or the socket to force one away from the other.
There is also provided a mechanism for effecting this method wherein a tool for mechanically decoupling an electrical prong connection from an electrical socket connection comprises a rotatable arm for positioning about an interface of the prong connector and the socket connector, and a base for supporting the arm, wherein rotation of the arm pushes against both the base and one of the connectors causing a separation of the connectors from one another.
According to a preferred embodiment the rotatable arm of the decoupling mechanism comprises a rotatable rod with a cam shaped arm fixed at each end and a lever handle connected to one of the rod ends. The base comprises a plate that has an aperture for receiving mated prongs and sockets. The plate further comprises raised supports providing a restrictive path for the rod to travel along. According to a preferred method this mechanism is inserted about the interface of the card connector and the receptacle connector. To remove the card, the lever is pushed or pulled causing the rod to rotate within the raised supports. With this rotation the cam arms attached to the rod turn from a retracted position to push against the plate and the receptacle until the arms reach an extended position. The force exerted against the plate and the receptacle causes a separation of the card apart from the receptacle.
A guide can also be incorporated with the mechanism to facilitate decoupling of the card in a continuous linear direction apart from the receptacle with the card remaining parallel to the receptacle during disengagement. Four guide pins can be attached to the receptacle extending in the direction of the card, and four through-holes for the pins would be located in the plate. Movement of the pins through the holes guides decoupling of the card from the receptacle.
Embodiments for decoupling both a card comprising multiple circuit boards and for decoupling typical wall-plug connectors are also disclosed.
Of course cams have found a wide variety of applications in mechanical systems. Cams have even been used in conjunction with electrical connectors. See, for example, U.S. Pat. Nos. 3,997,747 and 4,261,631. As best understood, prior efforts to facilitate movement of electrical connectors with cam mechanisms has required both complex mechanical assemblies and modifications to otherwise standard connectors. Such specialized arrangements are often impractical in a cost-sensitive, high-volume manufacturing environment. Moreover, these known applications of cam mechanisms have not provided a solution to remove the torsional forces present during hand removal of a card. Further, the known systems are not useful in high density systems which place cards in small compact spaces.

Decoupling tool mechanism for electrical connectors


Intelligent rearrangement of icons on a desktop in response to changes in desktop size, such as orientation, may be provided using a number of approaches. Desktop area in multiple orientations may be divided into a grid having equal numbers of rows and columns, and placement of icons in each orientation may use common grid coordinates. Icons may alternatively be reflected along a diagonal of desktops in different orientations, such that some icon positional relationships may be maintained. Placement of icons on a desktop may be restricted to a predefined subset region of the desktop, where the subset region will fit in multiple orientations without requiring adjustment. Additionally, areas of a desktop in multiple orientations may be reserved for predefined types of icons, and changes in orientation may result in placement of icons in corresponding reserved areas based on icon attribute.

In today's digital world, the use of graphical user interfaces (GUIs) to display and manage computer information has become ubiquitous. For example, the WINDOWS™ (Microsoft Corporation, Redmond, Wash.) operating systems used in many personal computers employs a GUI desktop with various icons or indicia representing objects on the computer system. The icons may represent applications, data files, hardware components, shortcuts to Internet addresses, and any variety of other data.
For many users, the GUI desktop is a convenient location for temporary (or even permanent) storage of icons representing applications and data that the users wish to have available as they go about their daily business. Managing the arrangement of these icons, however, can become difficult if a large number of icons are displayed, as individual icons can quickly become lost in a sea of other icons.
The problem becomes even worse when the user makes changes to the GUI desktop. For example, today's display monitors often allow changes in orientation to switch from landscape to portrait mode, or vice versa. Making such size changes alters the orientation of the usable space on the GUI desktop, and can disrupt the user's icon organization, making it more difficult for the user to function. Accordingly, there is a need for an intelligent management of desktop items that can account for such changes.

Smart icon placement across desktop size changes


A device for restricting flow of a fluid, in particular the flow of water in a sanitary fitting, includes a substantially cylindrical, hollow inlet body for the fluid, and a substantially cylindrical outlet body for the fluid, which is connected to the inlet body so as to be rotatable about a common longitudinal axis, and conducts the fluid via a cross borehole and a following cavity in the direction of the longitudinal axis. A mixing chamber includes a lateral intake borehole from which a further fluid can be supplied from outside the outlet body A clamping device fixes the set radial position of the inlet body and the outlet body relative to each other.

The present invention relates to a device for restricting the flow of, for example, water in a sanitary fitting. A device of this type is, for example, used as a shower valve between a connecting pipe and a shower to restrict water flow and to save water.
From EP 0 693 970 B1 by the same applicant, there is known a water jet regulating device and flow restrictor for sanitary fittings. The throttling element described therein comprises a throttling plate having a water inlet borehole, the diameter thereof being adjusted in accordance with the desired flow restriction. For fine adjustment of the flow, a throttling screw including a valve tip projects into the inlet borehole. Precise flow adjustment can be accomplished via rotating said throttling screw. This known water jet regulating device has been proven practical has widely been used, in particular with sanitary taps. For realizing a wide range of flow restriction, the throttling plate having the inlet borehole may be replaced by another plate having a different borehole diameter. When manufacturers or users store a supply of different throttling plates, a wide range of applications in different fields can be covered.
Further, from EP 2 331 755 B1 by the same applicant, there is known a regulating device comprising a cylindrical throttling element. This cylindrical throttling element deflects the incoming water jet, guiding it into a mixing chamber where mixing with air can take place. In addition, fine adjustment of regulation of the water jet is accomplished by means of a regulating screw. Air admixture is adjustable and, in one setting, can be completely turned off.

Device for limiting the flow of a fluid, in particular the flow of water in a shower


A filter monitor for indicating the condition of an air filter in a room air conditioner to determine whether the filter is clogged. The filter monitor assembly includes a shell mounted on the front of the air conditioner, with an air pressure equalization passage permitting air flow through the shell when a clogged air filter creates a negative air pressure inside the air conditioner housing. A signal flag within the shell is normally retracted by the force of gravity, but is visibly extended outside the shell by the pressure-induced air flow through the shell, indicating that the air filter is clogged.

Window-mounted domestic room air conditioners provide an effective and economical means for cooling the air in a limited living space. These units are a popular alternative to central air conditioning systems, which cool the entire household by circulating the conditioned air through the house central air duct system. The central air duct system often includes some form of air filtration system to remove airborne particulate matter from the recirculated air stream. Air filtration is desirable to provide a cleaner and healthier living environment in the house.
For these same reasons, it is desirable to provide air filtration means on window-mounted air conditioners. A filter may be located inside a window-mounted air conditioner housing directly behind the air inlet duct, so that air which is drawn into the air inlet by the air conditioner internal fan first passes through the filter element, and then passes through the heat exchange coil to be cooled before exiting to the room environment.
It is important that the air filter is changed or cleaned on a regular basis because after a period of time the filter will become partially clogged with trapped particles. When the filter becomes clogged, it reduces the flow of air into the unit, thereby reducing the effectiveness of the air conditioner. It is therefore desirable to provide some method of signalling that the filter is clogged and requires changing.
In the past, this problem has been addressed in a variety of ways. U.S. Pat. No. 3,263,403 discloses an air conditioner filter condition indicator that has a float inside a transparent tube on the front of the housing, such that when the filter is clogged the float is visible through a cutout window in the control knob to indicate that the filter requires changing. U.S. Pat. No. 3,201,772 discloses an air conditioner in which the increased air pressure against the clogged filter causes the filter element to drop onto a mechanical lever which causes a visual signal to be displayed in a window on the air conditioner housing.
Among the drawbacks of these prior systems are decreased visual aesthetics, since the indicator window or tube is always visible. Also of concern are the cost of the parts of the prior systems, the number of parts involved in such systems, the amount of modification required to the air conditioner housing to install a particular system, and the manufacturability of units incorporating such systems.