In a pulse width modulated inverter, the fit of a selected switching angle is monitored by counting zero crossings in a neighborhood of the function ##EQU1## for each harmonic of interest. If the fit is bad, a switching angle is moved to improve the fit.

1. Field of the Invention
The present invention generally relates to pulse width modulated (PWM) inverters and, more particularly, to an enhanced real-time control of a PWM inverter which monitors output harmonics and reduces output harmonics by a vernier change in position of a single switching angle.
2. Description of the Prior Art
PWM inverters are employed to convert direct current (d.c.) to alternating current (a.c.). In many applications, it is important to carefully regulate the quality of the a.c. generated by the inverter. Accordingly, it is customary to define a point of regulation (POR) downstream of the inverter at which the voltage and current of the a.c. signal generated by the inverter is sampled. The sampled voltage and current would be used to select appropriate PWM switching patterns to minimize distortion at the POR. Based on the voltage and current sensed at the POR, and in some systems also link ripple, an inverter controller selects one PWM pattern from a number cf stored patterns (or creates a pattern in real time) to provide the least harmonic distortion at the POR. As real and reactive power factors of electrical loads coupled to the inverter change, the PWM pattern used to control to the inverter switches change. A PWM pattern comprises a set of switching transients which, when applied to a d.c. signal via an inverter, produces alternating pulses which, when filtered, approximates a sinusoidal a.c. signal. The pulses in a PWM pattern are of varying width. Normally, the inverter can adequately reproduce the PWM pattern and thereby create an accurate approximation of a sinusoidal a.c. signal from the d.c. voltage. However, under some load conditions (particularly when loads are unbalanced or have particular real or reactive power components), the inverter controller selects a PWM pattern which has switching transients defining pulses which cannot be faithfully reproduced by the inverter due to physical limitations of transistor switches therein. In other words, the transistor switches within the inverter have physical limitations which manifest themselves, among other ways, in a minimum allowable switching time. Thus, should the inverter switch be called upon to switch faster than it is able, it will be unable to do so and, therefore, will be unable to faithfully reproduce a part of the PWM pattern required to maintain the least distortion at the POR. Accordingly, under some conditions, the POR cannot be regulated due to physical limitations of the transistor switches in the inverter. In addition, the wide range of link ripple and load variation require more patterns than can economically be stored if a reasonable degree of regulation is required. Thus, it is not practical to select a new pattern for small changes in load conditions.
Prior inventions have addressed schemes for controlling current and voltage at the POR. Representative of such inventions is U.S. Pat. No. 4,527,226 to Glennon, which discloses an inverter control system for a PWM inverter circuit. This circuit comprises an angle set look up table and selection logic for addressing the look up table. The angle set defining the inverter output waveform is selected in response to various operating conditions of the inverter.
An earlier patent to Glennon, U.S. Pat. No. 4,382,275, is directed to a PWM inverter having an output signal with reduced harmonic content, wherein a filtered fundamental PWM signal is summed with a controlled signal.
U.S. Pat. No. 4,595,976 to Parro, II discloses an inverter control which is an enhancement of the Glennon inverter control. More specifically, the table look up is implemented as a plurality of memories, one for each phase, each of which is subdivided into a plurality of memory blocks which store a number of bytes. Memory address decoding logic addresses a particular memory block in each memory in accordance with a control signal representing the desired waveform to be generated at each phase output. Thus, the Parro, II inverter control accomplishes individual phase regulation of the inverter output.
U.S. Pat. No. 4,635,177 to Shekhawat et al., discloses a further refinement of the basic Glennon inverter control system. More specifically, the Shekhawat et al., control permits on-line generation of PWM patterns for a neutral point clamped PWM inverter. A microprocessor and memory are coupled to the generating circuitry for calculating switching points for the inverter switches during operation of the inverter. Timer modules are coupled to the microprocessor for developing switch points so that the switches are operated to reduce the distortion of the inverter output signal.
U.S. Pat. No. 4,480,299 to Muto et al., also discloses a microprocessor controller inverter control. However, the Muto et al., PWM inverter is controlled by the use of the fundamental wave voltage of the inverter output as a feedback quantity. Muto et al. fail to show any apparatus for directly dealing with the physical limitations within the inverter itself.
Other patents related to the art of inverters include U.S. Pat. Nos. 3,648,150 to Kerick et al., and 4,626,979 to JaQuay. The Kerick et al., patent discloses an apparatus for comparing a filtered output of a PWM inverter with a reference waveform and generating output voltage signal to control the inverter drive circuit to produce an output waveform substantially duplicating the reference waveform. The JaQuay patent is similar to the Kerick et al. patent in that it is directed to a PWM inverter, including a comparator for comparing an output voltage with the sum of a reference voltage and a maximum allowable ripple voltage.
Also representative of the prior art are U.S. Pat. Nos. 4,646,221 to Sekino et al., 4,757,434 to Kawabata et al., 4,800,478 to Takahashi, and 4,757,432 to Hancock. The patent to Sekino et al., is directed to a controlling circuit which monitors the output waveform of the inverter and controls the firing of the switch elements in the inverter to restore it to a sinusoidal waveform in the event that it is distorted by nonlinear loads. The patent to Kawabata et al., is directed to a control circuit for a current control minor loop which monitors the instantaneous value of the output current of the power conversion apparatus and adjusts it to the current reference value. The patent to Takahashi is directed to a control for an inverter, wherein an evaluation function on the whole combination of the inverter and the load connected to the a.c. side of the inverter is minimized. The patent to Hancock is directed to a device for time integrating the difference between the electrical output and the reference by varying the switching frequency in the inverters so as to null the time integrated difference in a feedback control loop.

Enhanced real-time control of PWM inverter


A fluorescent substrate includes a base having a reflective surface and a flat bottom surface, and a fluorescent layer disposed on the reflective surface of the base such that the reflective surface of the base directs, outward from the wheel, fluorescence emitted from the fluorescent layer due to its excitation by exciting light. The reflective surface of the base has an array of minute reflective structures formed thereon so as to reflect, outward from the reflective surface, fluorescence emitted substantially parallel to the flat bottom surface of the base from the fluorescent layer.

1. Field of the Invention
The present invention relates to a fluorescent body device, and more particularly to a fluorescent wheel with a fluorescent layer thereon which is rotated by a motor to emit selected fluorescence due to irradiation of exciting light of a predetermined wavelength, a light source device including the fluorescent wheel, and a projector which includes the light source device and which projects a color image onto a display screen.
2. Description of the Related Art
Recently, in various electronic devices, light sources are used which include a light emitting diode or a laser diode, or emits organic electro-luminescence or fluorescence. The light sources which emits fluorescence increases the density of energy of exciting light to be applied to the fluorescent substances included therein or increases the output of the exciting light to provide light of high luminance. These light sources are used in various fields, for example, of television or illumination applications. Various proposals are made for light sources using fluorescent luminescence in order to provide light of much higher luminance.
In order to increase the energy density or output of the exciting light, it is required to use an exciting light source which consumes a large quantity of electricity or a large-type exciting light source. Thus, these light sources are difficult to be used in electronic devices whose sizes have been reduced recently.
For example, JP 117-37511 proposes a face discharge matrix type plasma display panel where each of unit luminescence areas of the panel is increased by making rugged fluorescent layers covering the outer surfaces of adjacent isolation walls between which the unit luminescence area is defined, thereby increasing its whole luminescent area and luminance.
JP2005-277331 proposes a luminescent device that includes a light emitting device located at a center of a truncated conical recess in a reflector with a remaining space of its conical recess filled with an optically transparent substance containing dispersed fluorescent substances to increase the efficiency of luminescence from the fluorescent layer.
As described above, in order to obtain fluorescence of high luminance in the fluorescent light source, its luminescent area is increased or its fluorescence emitted in every directions is collected and used. However, in the above proposals, most of the fluorescence emitted in directions substantially parallel to the fluorescence emission surface of the fluorescent layer is useless and hence the use efficiency of the fluorescence is low.
Assume that a laser beam of high energy density is used as the exciting light source in a fluorescent wheel which has a reflective flat surface on which the fluorescent layer is provided to emit fluorescence when irradiated with exciting light. In this case, there is a high possibility that coherent light of high energy which has passed through the fluorescent layer and has been reflected by the reflective surface will be emitted as it is outward from the fluorescent wheel.
The present invention is directed to providing a fluorescent wheel of high use efficiency of fluorescence, a high safety light source capable of emitting light of high luminance, and a projector using such light source device.

Fluorescent wheel, light source device and projector


The present invention relates to an apparatus to measure permeation of a gas through a membrane. The membrane is mounted on a flange with two sealing areas. The region between the sealing areas defines an annular space. The annular space is swept with a gas in order to carry away any of the permeating gas which may leak through the sealing areas.

Current industry practice for evaluating ultrabarrier performance against water vapor transmission is to use a method that measures actual water transmission. These methods include coulometry (U.S. Pat. No. 7,569,128, MOCON, Inc.), detection of radioactive HTO (U.S. Pat. No. 7,257,990, General Atomics) and optical transmission through calcium (U.S. Pat. No. 7,117,720, Philips Electronics). All three of these approaches have severe limitations. They are all water based, and therefore inherently slow. The time required for establishment of steady state diffusion through a membrane is 5 to 10 times ts, where ts=I2/6D. I is the thickness of the membrane, and D is the diffusivity of the permeant. In the case of water diffusing through PET, D is ˜4×10−9 cm2/s at 25 C, so that for a 5 mil (0.005 inch) thick membrane. The minimum measurement time is 10 to 20 hours. In practice, even longer measurement times are required, because the tests involve vapor transmission rates at or near the limit of sensitivity for each technique. Therefore, significant averaging is required to compensate for the poor signal to noise ratio. As a result, it takes on the order of 1 week to be confident that the transmission rate of an ultrabarrier is at or below the detection limit of either a coloumbic detection system or a radioactive tritium measurement. It takes even longer for the calcium test, because it takes a week or more for the measurement cell to achieve internal equilibrium and start to exhibit a steady state transmission rate.
In addition to their slow measurement rates, the above techniques are also limited in their sensitivity. According to product literature from MOCON® Minneapolis, Minn., the limit to their measurement technique is 5×10−4 g/m2/day. The limit of the calcium test is an order of magnitude lower: 5×10−5 g/m2/day. The requirement for an ultrabarrier layer for CIGS solar cells or OLED display devices is ˜10−6 g/m2/day, making the tritium test, having a reported detection limit of 2×10−7 g/m2/day, the only technique sufficiently sensitive to verify performance at the required level. Even this test is not really sensitive enough, however, as efficient statistical sampling methods for process control require a continuous measure of the process, both in the out-of-limits and within-limits regimes. The HTO test could only provide such a measure for permeation rates that are just within the control limits, and in most cases could only provide a "pass/fail" type of response. The statistical requirements on "pass/fail" type measurements are so burdensome as to render process control essentially impossible.
The solution to the first limitation of these methods, the long measurement time, is to use an alternative test gas as a proxy for the water. Helium, for example, has a diffusivity in PET that is 500 times larger than that of water. As a result, ts for helium diffusing through a 5 mil membrane is about 15 seconds, resulting in a measurement time on the order of minutes. Such a substitution is a valid probe of the barrier properties, because permeation through an ultrabarrier occurs via micropores in the inorganic layer, rather than by permeation of the inorganic material itself. Once a correlation has been established between water vapor transmission and helium permeation for the bare PET (or other polymer) substrate, a rapid helium-based test can give a reliable value for the water vapor transmission rate (WVTR).
The required sensitivity for a test and measurement system based on the helium proxy principle is straightforward to estimate. The noise floor of the calcium test represents a reduction in WVTR over the bare substrate by a factor of 40000. From the permeation rate of helium through PET (˜2×10−8 scc/cm/s/atm), and assuming a 10 cm diameter membrane and a driving pressure differential of 1 atm, this 40000 reduction factor gives a helium transmission rate of 3×10−9 scc/s, well within the range of commercial helium mass spectrometer systems. To be useful as a process control technique, however, requires a sensitivity two orders of magnitude below that. Fortunately, state of the art, oil-free helium mass spectrometers are specified to have a sensitivity of 5×10−12 scc/s which is three orders of magnitude below the calcium test limit.
Yilvisaker (U.S. Pat. No. 5,361,625) describes passage of gas through a membrane by exposing one side of the film to a test gas and exposing the other side of the film to a carrier gas.
In practice, however, measurements are limited by the background helium signal due to permeation through elastomer seals. Therefore, there is a need for an apparatus designed to hold ultrabarrier membranes for testing, while reducing or eliminating this background signal.

Apparatus to measure permeation of a gas through a membrane


An electronic device can include a battery bus, a load having a transient power requirement, and a transient power management circuit coupled between the battery bus and the load and configured to meet the transient instantaneous power requirement of the load while maintaining a minimum voltage on the battery bus. The transient power management circuit can include a boost converter coupled between the battery bus and a capacitor bank, and the load may be coupled to the capacitor bank. A control circuit may be configured to operate the boost converter to charge the capacitor bank. A control switch may be coupled between the boost converter and the capacitor bank, and the control circuit may be further configured to limit inrush current into the capacitor bank. Additionally, a state of charge of the battery may be estimated from a time required to charge the capacitor bank.

Advances in microelectronic circuits have allowed for creation of electronic devices having smaller and smaller footprints with ever increasing computational and communication capabilities. These advances have allowed for creation of new classes of electronic devices. Various challenges exist in providing power to such devices. It is generally desirable to power small portable or personal electronic devices with batteries. Much attention has been focused on high energy density rechargeable cells/batteries, such as lithium ion cells/batteries, for applications such as laptop and notebook computers, tablet computers, smartphones, and the like. However, for some applications, other battery chemistries may provide a better solution.
As an example, for applications in which the average power requirement is very low, it may be preferable to use a lithium metal cell/battery. Lithium metal cells are designed to have relatively long lifetimes as compared to many other battery chemistries. This may be advantageous from a user perspective, because it reduces the frequency with which the user must change the cells/batteries. Additionally, lithium metal cells are widely available in a "coin cell" form factor, including the CR20xx series, which makes sourcing replacement cells/batteries easy for the user. However, lithium metal cells may be somewhat limited in their instantaneous power delivery capabilities with respect to other battery chemistries. As a result, even if the average power requirements of an electronic device are sufficiently low, some transient power requirements of a device may be such that use of a lithium metal cell (or other long-life optimized cell) compromises operation of the device in situations calling for high but transient instantaneous power delivery.
Thus, what is needed in the art are circuits and techniques for adapting long-life optimized cells/batteries for use in devices that have relatively low average power requirements, but which may have relatively high, but transient, instantaneous power requirements.


According to one aspect, the subject matter described herein comprises methods, systems, and computer program products for automatically adjusting a replication rate based on a specified quality of service (QoS) level. The method includes providing for the specification of a QoS level associated with the performance of at least one application operating on a data storage system and determining a performance measure of the at least one application. A data replication rate of the data storage system is also determined and, based on the QoS level and the performance measure of the at least one application, the data replication rate is automatically adjusted.

In a data storage environment, data may be distributed across one or more physical data storage devices, such as one or more disk drives, and may be divided into logical representations of a physical memory address space. In a data storage environment, input/output (I/O) operations may request access to data in order to perform particular operations. I/O operations may include read, write, copy, and delete operations and are typically associated with an application or process operating in the data storage environment.
In addition to providing logical access to physically distributed data storage, data storage environments may support generating and maintaining multiple copies of data located in a distributed manner. As used herein, the term "replica" refers to a copy of data located in a data storage and replication system, and the term "replication" refers to the process of generating replicas (i.e. copying data). Therefore, data storage systems supporting data replication may be referred to as data storage and replication systems.
In a data storage and replication system, data may be replicated for a variety of purposes. For example, data may be replicated within an array based on user input, data may be replicated for continuously maintaining an up-to-date copies of source data (i.e. "data mirroring"), and/or data may be replicated for creating point-in-time backups of source data (i.e "snapshots"). Thus, data replication refers to copying data for any suitable purpose in a data storage and replication system, including mirroring and making snapshots.
In addition to the aspects described above, conventional data replication systems may allow a user to specify one or more quality of service (QoS) levels associated with applications operating on the system. A QoS level is an expression of a performance objective associated with an application or process operating in a data storage and replication environment. For example, a QoS level may include a limit to be placed on the use of a system setting or parameter, such as maximum I/O latency, maximum I/O queue depth, etc. Alternatively, a QoS level may include a high-level performance objective, such as the time period within which an application must complete a task.
In conventional QoS-enabled data storage and replication systems, a QoS level may fail to be achieved if a data replication process overutilizes a shared system resource. For example, a replication process may copy a large amount of data within a data storage array, thus requiring a large amount of system resources. Replication may heavily utilize I/O buffers, internal link bandwidth, external link bandwidth, disk resources, and CPU processing resources. Yet these system resources may also be shared by one or more applications whose performance may suffer as a result. This may include failing to achieve a specified QoS level in some instances that require access to the shared I/O buffers, internal link bandwidth, and CPU resources which were overutilized by the replication operation.
Therefore, one problem associated with conventional data storage and replication systems is that applications may be adversely affected by replication processes sharing the same system resources. Because data storage and replication systems contain a finite amount of available resources (i.e. link bandwidth, CPU resources, etc.), application performance may suffer in response to unmanaged spikes in data replication resource use.
One conventional solution to the potentially negative impact on application performance described above, including the failure to meet specified QoS objectives, that may result from an unmanaged data replication rate includes allowing a user to manually adjust the maximum allowable replication rate (MARR). For example, a user may manually set a globally-applicable and static maximum allowable replication rate for a data storage and replication system. After being initially set, the maximum allowable replication rate may be manually adjusted by the user by selecting a higher or lower allowable rate. After adjustment, the maximum allowable replication rate remains constant (i.e static) until it is manually adjusted again by the user. Typically, data storage and replication systems provide for a variety of settings corresponding to a range of maximum allowable replication rates. For example, "low" "medium" and "high" settings may correspond to maximum replication rates of 25 Mb/s, 50 Mb/s, and 75 Mb/s, respectively.
One problem associated with manually adjusting a data replication rate in a QoS-enabled data storage and replication system is that optimal allocation and/or balancing of system resources between applications and replication operations is unlikely to be achieved. Specifically, system resource demands change dynamically yet manually configured maximum allowable replication rates are static. At any given time, therefore, system resources may be over- or under-provisioned from the level necessary to meet specified QoS objectives. For example, in a data replication system where a maximum allowable replication rate is manually set to "high" and where both a high-priority application and a replication process share a specific set of system resources, the system resources utilized by the replication process at the "high" rate may prevent enough resources from being simultaneously available to the high-priority application. Thus, the high-priority application may become 'starved' for system resources and its performance may suffer accordingly (i.e. fail to meet its QoS objectives). Alternatively, if manual adjustment of the data replication rate is set too low, the replication process may not complete its duties fast enough to meet its QoS objective while, at the same time, there exists an over-provisioning of resources dedicated to non-replication applications. Either scenario results in suboptimal system resource utilization.
Accordingly, in light of these difficulties associated with conventional manual adjustment of the replication rate in data replication systems, there exists a need for improved methods, systems, and computer program products for automatically adjusting a replication rate based on a specified QoS level.

Methods, systems, and computer program products for automatically adjusting a data replication rate based on a specified quality of service (QoS) level


A solid fuel heating apparatus (1) comprising a combustion chamber provided with a glass door (4) opening to the outside, an intake device (11) for the intake of outside combustion air into said chamber, an outlet duct for the burnt gases (2) and a sealed preheating enclosure for preheating the combustion air, conveying said air to the combustion chamber, connected at a first end to the intake device (11) and ending at a second end with a plurality of openings (9) releasing the air preheated by the preheating enclosure into the combustion chamber, characterized in that the preheating enclosure consists of a set of sealed heat exchanging pipes containing the combustion gases and the burnt gases (3, 8, 12, 15, 17, 18, 19), ending with the abovementioned openings (9), which are variable in size and are arranged in such a way as to modulate the flow of preheated air released into the chamber, enclosing the flame and combustion area in the natural conical shape of said chamber.

Home stoves have always been given a casing that recalls daily-life objects, for example with a shape inspired by a piece of furniture or a clock. Thus, several generations of stoves have followed one another with a lifetime of at least forty years each: the bell stove, the Franklin stove, the ceramics step stove, the Godin-type stove, the cabinet stove, the convection stove, the cast-iron stove, the chimney stove, etc. Currently, a new generation of stoves, namely steel stoves of contemporary style, is supplanting cast-iron stoves.
Furthermore, household heating apparatuses using solid, liquid or gas fuel currently available on the market have a shape that is generally cubic, cylindrical, trapezoidal, etc., whether they are stand-alone apparatuses or inserted into masonry or a wall. One way of giving the current stoves a contemporary design, recalling daily-life objects that are currently in style and "trendy", such as flat-screen televisions, smart phones or electronic tablets, is to make them both shallow, or even very shallow, and visually accessible from different angles, or even panoramic (FIGS. 1A and 1B).
However, the dimensions of most commercially-available stoves are often within the following limits:    height: 35-120 cm;    width: 30-100 cm;    depth: 30-70 cm.
The aforementioned dimensions, as well as the other features of current stoves, generally give them either a heavy or a bulky look, with related excess costs in terms of material, energy and handling.
These apparatuses may be very heavy and their weight may typically vary between 40 and 250 kg, depending on power. When they are inserted, these apparatuses require imposing masonry.
The depth is a particularly important parameter, since it determines the space available to fasten the door or window, and the back of the stove, as well as the size of the combustion chamber.
For example, in the case of woodstoves, it is difficult to reduce the depth of the stove given the restriction on the space available for inserting the logs, since the latter tend to pile on top of one another at the bottom of the stove and suffocate the combustion when the depth is reduced.
In general, it is observed that combustion in a narrow space using the prior-art combustion systems is not satisfactory: the yield is very average and the window quickly becomes dirty.
Until the end of the 1970s, woodstoves were supplied with fresh air coming from the grate at the bottom of the chamber, resulting in a tendency to make the stove deeper in order to avoid dirtying the window. Another solution was to suppress the windows, or to reduce them or to equip the stove with windows decorated with cast iron in order to hide the fouling.
A first way of trying to solve this problem of dirtying was to introduce fresh air along the window to create an air curtain that prevents the deposition of combustion residues and conveys them toward the rear of the chamber. However, introducing cold air or air at ambient temperature into a combustion chamber brought to a temperature of between 300 and 600° C. disrupts the combustion, and the efficiency is hence not optimized and the polluting emissions remain high.
In order to solve this problem, all (except in the startup phase) or part of the primary air introduced was preheated by contact with the hot walls of the chamber in secondary, or even tertiary, ducts, which defines a second and third combustion area (for example, see the "Woodbox"® patent—EP 1 563 228 B1, 100% primary air preheated safe startup). The stoves then become very complex and very expensive to manufacture.
Since the combustion occurs on several levels, the smoke crossing the incoming air, opening the door to reload with fuel may cause the living space to become smoky. To avoid this, it is necessary to improve the combustion by eliminating parasitic air intakes, therefore by making the chamber as sealed as possible, for example with a triple-walled loading door, which is again very expensive.
It is also difficult to reduce the depth of the prior-art stoves without significantly decreasing the volume of the combustion chamber, since a dual preheating duct for the primary air is often provided in the back and side walls of the apparatus, to promote good combustion.
In order to avoid significant dirtying at the level of the window, it is also necessary to burn "noble" wood i.e., expensive wood varieties such as oak, beech, hornbeam or birch, for example.
Several manufacturers have tried to give their heating apparatuses a "narrow" look by adding a frame around the existing apparatus. The total depth of these apparatuses, however, remains unchanged.
Furthermore, heating apparatuses working off gas are also known in which the preheating of the primary air comprises a dual enclosure that is concentric to the discharge duct for the burnt gases, which allows to recover part of the heat that is lost through the evacuation of smoke to preheat the incoming primary air.
Document EP 1 985 928 A1 describes a panoramic multi-fueled heating apparatus, where the primary air taken from outside the chamber is preheated in a dual-enclosure duct that is concentric with the hot discharge duct for the burnt gases. A heat exchanger situated in the crown of the furnace is used both as a baffle to slow down the discharge of the burnt gases and as a deflector that contributes to distributing all of the preheated air along the window(s), in the upper part of the combustion chamber.

Very shallow heating apparatus with very high yield and a wide view


An aryl composition includes aryl ether oligomers. These compositions may be prepared by reaction of one or more dihalobenzenes with one or more dihydroxybenzenes by an Ullman ether reaction. The oligomers may have two or more benzene rings and include terminal halogen, e.g., bromine (Br), or hydroxyl (OH) groups. These oligomers may be brominated to form flame retardant compositions for thermoplastic polymers.

Decabromodiphenyl oxide (deca) and decabromodiphenylethane (deca-DPE) are commercially available materials widely used to flame retard various polymer resin systems. The structure of these materials is as follows:

One of the advantages of using deca and deca-DPE in polymer resins that are difficult to flame retard, such as high-impact polystyrene (HIPS) and polyolefins, is that the materials have a very high (82-83%) bromine content. This allows a lower load level in the overall formulation, which in turn serves to minimize any negative effects of the flame retardant on the mechanical properties of the polymer.
Despite the commercial success of deca, there remains significant interest in developing alternative halogenated flame retardant materials that are equally or more efficient, not only because of economic pressures but also because they may allow lower flame retardant loadings, which in turn may impart improved performance properties. Improved properties, such as non-blooming formulations, or better mechanical properties can potentially be met by producing polymeric or oligomeric flame retardant compounds. These types of materials would become entangled in the base resin polymer matrix, depending on the compatibility, and hence should show fewer tendencies to bloom.
There are a number of commercially available flame retardant materials that can be considered oligomers or polymers of halogenated monomers. Examples of these monomers include tetrabromobisphenol A (TBBPA) and dibromostyrene (DBS), which have the following structures:

Commercially, TBBPA and DBS are typically not used in their monomeric form, but are converted into an oligomeric or polymeric species. One class of oligomers is the brominated carbonate oligomers based on TBBPA. These are commercially available from Chemtura Corporation (examples include Great Lakes BC-52™, Great Lakes BC-52HP™, and Great Lakes BC-58™) and by Teijin Chemical (FireGuard 7500 and FireGuard 8500). These products are used primarily as flame retardants for polycarbonate and polyesters.
Brominated epoxy oligomers, based on condensation of TBBPA and epichlorohydrin, are commercially available and sold by Dainippon Ink and Chemicals under the Epiclon® series, and also by ICL Industrial Products (examples are F-2016 and F-2100) and other suppliers. The brominated epoxy oligomers find use as flame retardants for various thermoplastics both alone and in blends with other flame retardants.
Another class of brominated polymeric flame retardants based on TBBPA is exemplified by Teijin FG-3000, a copolymer of TBBPA and 1,2-dibromoethane. This aralkyl ether finds use in ABS and other styrenic polymers. Alternative end-groups, such as aryl or methoxy, on this polymer are also known as exemplified by materials described in U.S. Pat. No. 4,258,175 and U.S. Pat. No. 5,530,044. The non-reactive end-groups are claimed to improve the thermal stability of the flame retardant.
TBBPA is also converted into many other different types of epoxy resin copolymer oligomers by chain-extension reactions with other difunctional epoxy resin compounds, for example, by reaction with the diglycidylether of bisphenol A. Typical examples of these types of epoxy resin products are D.E.R.™ 539 by the Dow Chemical Company, or Epon™ 828 by Hexion Corporation. These products are used mainly in the manufacture of printed circuit boards.
DBS is made for captive use by Chemtura Corporation and is sold as several different polymeric species (Great Lakes PDBS-80™, Great Lakes PBS-64™, and Firemaster CP44-HF™) to make poly(bromostyrene) type flame retardants. These materials represent homopolymers or copolymers. Additionally, similar brominated polystyrene type flame retardants are commercially available from Albemarle Chemical Corporation (Saytex® HP-3010, Saytex® HP-7010, and PyroChek 68PB). All these polymeric products are used to flame retard thermoplastics such as polyamides and polyesters.
Unfortunately, one of the key drawbacks of the existing brominated polymer materials is their relatively low bromine content, which makes them less efficient as a flame retardant and consequently typically has a negative effect on the desirable physical properties of the flame retardant formulations containing them, such as impact strength. For example, whereas deca and deca-DPE contain 82-83% bromine, oligomers or polymers based on the brominated monomers mentioned above generally have a bromine content in the range of 52% -68%, depending on the material. This therefore typically requires a flame retardant loading level in a polymer formulation significantly higher than that required for deca, often resulting in inferior mechanical properties for the formulation.
Other considerations also influence the impact the flame retardant has on the final properties of the formulated resin. These considerations include the flame retardant thermal stability and the compatibility with the host resin. In situations where these other considerations are relatively constant, the bromine content, and hence flame retardant load level, has a major influence on the properties of the overall formulation.
To address the need for flame retardant materials that to not detract from the mechanical properties of the target resin, we have now developed a family of materials that can be classified as halogenated, and particularly brominated, aryl ether oligomers. In particular, we have found that the use of these halogenated aryl ether oligomers results in superior mechanical properties in resins such as HIPS and polyolefins and that the materials also provide excellent properties in engineering thermoplastics such as polyamides and polyesters. The aryl ether oligomers can be halogenated to a higher level than the oligomers and polymers that are commercially available today, which should have a positive effect on their mechanical property performance. It is also found that these aryl aryl ether oligomers, even at lower levels of halogenation, give formulations with acceptable mechanical properties.
Japanese Unexamined Patent Application Publication 2-129,137 discloses flame retardant polymer compositions in which the polymer is compounded a with halogenated bis(4-phenoxyphenyl)ether shown as follows:
in which X is a halogen atom, a and d are numbers in the range of 1-5, and b and c are numbers in the range of 1-4. However, the flame retardant is produced by brominating the bis(4-phenoxyphenyl)ether as a discrete compound and not an oligomeric material obtained by polymerizing an aryl ether monomer. In contrast, employing a material having an oligomeric distribution is believed to improve its performance properties as a flame retardant.
U.S. Pat. No. 3,760,003 discloses halogenated polyphenyl ether flame retardants having the general formula:
wherein each X is independently Cl or Br, each m is independently an integer of 0 to 5, each p is independently an integer of 0 to 4, n is an integer of 2 to 4, and 50% or more by weight of the compound is halogen. The ether precursors again appear to be discrete non-polymeric materials and are halogenated by reaction with bromine in the presence of iron powder as a catalyst and optionally methylene bromide. After the reaction is complete, the excess bromine is flash vaporized, leaving behind the desired solid product.
In an article entitled "Synthesis and Stationary Phase Properties of Bromo Phenyl Ethers, Journal of Chromatography, 267 (1983), pages 293-301, Dhanesar et al disclose a process for the site-specific bromination of phenyl ethers containing from 2 to 7 benzene rings. Again the ethers appear to be discrete compounds with no oligomeric distribution and, although the products are said to be useful in the separation of organic compounds, no reference is given to their possible use as flame retardants.
United States Patent Application Publication Number US 2008/0269416, which corresponds to International Publication Number WO 2008/134294, describes a halogenated aryl ether oligomer that comprises the following repeating monomeric units:
wherein R is hydrogen or alkyl, especially C1 to C4 alkyl, Hal is halogen, normally bromine, m is at least 1, n is 0 to 3 and x is at least 2, such as 3 to 100,000, for example 5 to 20. These oligomers may be prepared by brominating an intermediate oligomer composition. In Example 8 of US 2008/026416 and WO 2008/134294, the intermediate oligomer composition is prepared by an Ullmann ether reaction of resorcinol and 1,4-dibromobenzene in a 1:1 molar ratio and in the presence of a cuprous iodide (i.e. CuI) catalyst. In Example 9 of US 2008/0269416 and WO 2008/134294, the intermediate oligomer composition is prepared by oligomerizing 3-bromophenol. In Example 10 of US 2008/0269416 and WO 2008/134294, the intermediate oligomer composition is prepared by oligomerizing 4-bromophenol.
In our co-pending U.S. Provisional Patent Application No. 61/139,282, filed Dec. 19, 2008, we have described a flame retardant blend comprising at least first and second halogenated phenyl ethers having the general formula:
wherein each X is independently Cl or Br, each m is independently an integer of 1 to 5, each p is independently an integer of 1 to 4, n is an integer of 1 to 5 and wherein the values of n for the first and second ethers are different. Bromination is conveniently effected by adding bromine to a solution of the blended ether precursors in dichloromethane also containing an aluminum chloride catalyst. The reaction temperature is kept at 30° C. and the HBr off-gas is captured in a water trap. After the HBr evolution subsides, the material is worked up to give the product as an off-white solid.
WO2008/156928 discloses optoelectronic polymer compositions made from brominated polyarylethers having pendant carbazolyl groups. Useful polyarylethers are made by nucleophilic displacement condensation reactions between bisphenols and dihalogenated monomers. The resultant polyarylethers are then subjected to electrophilic aromatic substitution with bromine followed by nucleophilic aromatic substitution with a carbazole compound. Bromine substitution is typically effected by adding bromine dropwise to a solution of the ether in chloroform followed by precipitation with methanol.
The synthesis of aryl ethers via the Ullmann ether reaction has been reviewed quite extensively and has been known for over 100 years. Articles on this subject include Ley, S. V. and Thomas, A. W. Angew. Chem. Int. Ed. 2003, 42, 5400-5449; Sawyer, J. S. Tetrahedron, 2000, 56, 5045-5065; Lindley, James Tetrahedron, 1984, 40(9), 1433-1456; and Frlan, R. and Kikelj, D. Synthesis, 2006, 14, 2271-2285. The vast majority of information on this subject deals with making diaryl ethers from aryl halides and phenoxides and only a very small portion covers any research on making polymers or oligomers using this technology. In a 1945 review by Ungnade, H. E. Chemical Reviews, 1946, 38, 405-414; citing Staudinger, H. and Staiger, F. Ann. 1935, 517, 67, it was disclosed that small-chain oligomer type aryl ethers were made from a stepwise build-up using the appropriate aryl halide and phenoxide. In this case, for example, the authors used the reaction of a 4-ring α,ω-dibromo aryl ether with potassium phenoxide to make a six-ring aryl ether species. Other small-chain oligomers made in this fashion have also been reported by Hammann, W. C. and Schisla, R. M. J. Chem. Eng. Data 1970, 15(2), 352-355.
The preparation of polymers or oligomers of aryl ethers has generally been done by either homopolymerization of a halophenol, or co-polymerization of an aryldihalide with an aryldiphenol. One of the earlier works done on the polymerization of bromophenol using Ullmann chemistry was by Stamatoff (DuPont), as described U.S. Pat. No. 3,228,910 and FR 1,301,174. In these patents, it was mentioned that the reaction was conducted in an inert solvent in which sodium phenate is soluble. In this case they used such solvents as dimethylacetamide, m-dimethoxy benzene, or nitrobenzene. The catalyst was a cuprous chloride—pyridine complex. In 1968, van Dort, et al, as described in van Dort, H. M., et al European Polymer Journal, 1968, 4, 275-287, made a polymer from para-bromophenol under Ullmann conditions by reacting the sodium salt of the phenol using a cuprous chloride—pyridine catalyst complex in dimethoxybenzene at temperatures up to 200° C. Another polymerization synthesis using p-bromophenol was from Jurek and McGrath, as described in Jurek, M. J. and McGrath, J. E. Polymer Preprints 1987, 28(1), 180-1. In this case they used a cuprous chloride—quinoline complex as the catalyst with benzophenone as the solvent and used reaction temperatures up to 210° C. They also used an azeotrope solvent, such as toluene, to remove the water formed during the reaction of bromophenol with base. Once the phenate was formed and the water was removed, the toluene was stripped from the reaction to allow the polymerization to proceed at the high temperatures required.
Access to aryl ether oligomers having meta-substitution by this route is not as easy, since the meta isomer for the bromphenol starting material is less available than the para isomer of bromophenol. The alternative approach of embodiments described herein can lead to meta substitution more easily, since, in the case of resorcinol, that material is already meta-substituted.
A series of papers appear from Keller, et al, regarding the formation of aryl ether oligomers by reactions of aryldihalides with aryldiphenols. These papers include Dominguez, D. D. and Keller, T. M. High Performance Polymers 2006, 18, 283-304; Laskoski, M.; Dominguez, D. D. and Keller, T. M. J. Polym. Sci. A: Polym. Chem. 2006, 44, 4559-4565; and Laskoski, M.; Dominguez, D. D. and Keller, T. M. Polymer 2006, 47, 3727-3733. The main focus of these publications is to make thermosetting cyanate ester or phthalonitrile based resins in which the reactive monomer groups are separated by aryl ether spacer groups. In the aryl ether synthesis, they use a process in which a diphenol (such as resorcinol) is reacted with an aryldihalide (such as 1,3-dibromobenzene) in a solvent system similar to that described above using toluene and DMF, where the toluene is used to azeotrope any water formed in the reaction. They use either cuprous iodide—1,10-phenanthroline or a triphenylphosphine—copper bromide complex as the catalyst system with potassium carbonate as the base. In all cases, the reactions were run with excess of the diphenol, so the oligomer that is formed would have reactive end groups for the next step in the synthesis. They showed that in this solvent system, they could use the potassium carbonate base instead of the more expensive cesium carbonate system developed by Buchwald and co-workers 10 years earlier, as described in Marcoux, J. F.; Doye, S. and Buchwald, S. L. J. Am. Chem. Soc. 1997, 119, 10539. One of the drawbacks in using a carbonate base for the reaction is that the excess solid base that is used would need to be dealt with in some fashion during product workup. Depending on the reaction concentration, the solid bases may also create problems in handling the resulting thick slurry. Two patents to Keller, et al, i.e. U.S. Pat. No. 6,891,014 B2 and U.S. Pat. No. 6,756,470 B2, also describe reactions run with an excess of diphenol to form oligomers with reactive hydroxyl end groups as intermediates for the preparation of desired oligomeric hydroxyl arylether phthalonitrile end products. However, these patents also mention that diphenols may be reacted with dihalobenzene in a 1:1 molar ratio or with the dihalobenzene in molar excess of the diphenol. In particular, it is stated at column 6, lines 16-20 of U.S. Pat. No. 6,891,014 B2 and at column 6, lines 32-35 of U.S. Pat. No. 6,756,470 B2 that a 2:1 molar ratio of m-diiodobenzene and hydroquinone would react to form oligomers, where the average chain has three benzene rings.
Other examples are found in the literature where aryl ether oligomers are prepared from reaction of diphenolics with aryldihalides. In a report by Lindley, et al, in 1985, i.e. Lindley, P. M.; Picklesimer, L. G.; Evans, B.; Arnold, F. E. and Kane, J. J. Arylether Sulfone Oligomers with Acetylene Termination from the Ullmann Ether Reaction, in ACS Symp. Ser. 282, Ch. 3, 1985, 31-42, potassium carbonate was used either in pyridine with cuprous iodide or in collidine with cuprous oxide. It was mentioned that formation of oligomers with more than three benzene rings could be minimized by using a large excess of the aryldibromide. Lindley further reports that the chain length for the formation of the aryl ether oligomers can be controlled by adjustment of the reaction stoichiometry. See Hedberg, F. L.; Unroe, M. R.; Lindley, P. M. and Hunsaker, M. E. Wright Patterson Air Force Base Technical Report AFWAL-TR-85-4041, 1985. Oligomers were obtained using resorcinol and 1,3-dibromobenzene at 1:10 and 1:2 mol ratios. In the single reaction where the molar ratio of resorcinol to 1,3-dibromobenzene was 1:2, the percent yield was reported as 49 wt %.
A U.S. patent by Famham, et al, i.e. U.S. Pat. No. 3,332,909, discloses that polyarylene polyethers can be made from reaction of a dihydric phenol with a dibromobenzenoid compound. They mention that an alkali metal hydroxide can be used to form the metal salt of the dihydric phenol and that the water formed in the reaction can be removed with the aid of an azeotropic solvent, such as toluene, with the main solvent being benzophenone and the catalyst being a cuprous salt, such as cuprous chloride—pyridine complex. In a 1989 patent, i.e. U.S. Pat. No. 4,870,153, Matzner, et al, discloses synthesis of poly(aryl ether) polymers by a similar approach using a cuprous halide catalyst as a pyridine complex in a solvent like benzophenone with reaction temperatures in the 180-220° C. range. Both authors also employ adding a monofunctional compound, such as bromobenzene toward the end of the reaction to endcap any residual phenolic species and also mention that the stoichiometry for the two reactants needs to be within 5% of 1:1, or the molecular weight would be significantly reduced.
In a 1998 paper, i.e. Lee, J. I.; Kwon, L. Y.; Kim, J.-H.; Choi, K.-Y. and Suh, D. H. Die Angewandte Makromolekulare Chemie 1998, 254, 27-32, Lee, et al discusses polymer formation using a CuCl-pyridine complex in N-methyl-2-pyrrolidone (NMP) with either potassium carbonate or NaOH as the base and using toluene as the azeotropic solvent for water removal.
The approaches discussed above require reaction times of near 24 hr to complete the reaction or reaction temperatures near 200° C. It would, therefore, be desirable to improve the catalyst system or solvent system that is used.
It would appear that improvements in copper catalyst systems for the Ullmann ether reaction have been occurring more frequently in the last 20 years in the reactions of various monohalo benzenes with certain phenols to make simple aryl ethers. The catalysts used in the vast majority of reports are cuprous salts. In a mechanistic paper, i.e. Weingarten, H. J. Org. Chem. 1964, 29, 3624-3626, involving such catalysts, it was mentioned that cupric species get converted into cuprous species during the reaction and that cuprous is the active catalytic species. A Great Britain patent, i.e. Wedemeyer, K. and Adolphen, G. GB 1,415,945 (1975), discussed using cupric oxide, cuprous oxide, cupric bromide, or cuprous bromide, etc., in the synthesis of small aryl ether molecules by reaction of a chlorophenol with excess dichlorobenzene. They needed to use a deficit of base to achieve reasonable yields in the reaction and needed about 30% of free phenol to be present to achieve the maximum 70-75% yield.
Advantages of using a cupric salt vs. cuprous in the Ullmann reaction of aryl ether oligomers or polymers do not appear to be described in the published literature. The molecular weights of cupric oxide, cuprous oxide and cuprous iodide are 79.55, 143.1, and 190.5 g/mol, respectively. Hence, at equivalent mole ratios, less cupric oxide is required.
One of the important factors affecting the progress of the Ullmann ether synthesis is the selection of the appropriate ligand system. A recent study, published in Chang, J. W. W. et al Tet. Lett. 2008, 49, 2018-2022, on the reaction to make diaryl ethers without added ligand using phenol and iodobenzene showed that 10% CuI catalyst was needed to achieve yields above 95% and the reaction required 22 hr. Using bromobenzene or less catalyst significantly reduced the yield. In another study, published in Williams, A. L.; Kinney, R. E. and Bridger, R. F. J. Org. Chem. 1967, 32, 2501-2505, using resorcinol as the reactant with bromobenzene, Williams showed that the complexing ability of the ligands and the solvent has a significant effect on the course of the reaction. The reaction in pyridine gave 70% yield, whereas the reaction in 91% pyridine/9% 2,2′-bipyridine gave only 31% yield. They interestingly mentioned that excess base in the reaction destroys the catalyst and that they ran the reactions using 95% of stoichiometric base.
There are some other reports on the effects of ligands on the Ullmann ether reaction. Goodbrand, in Goodbrand, H. B. and Hu, N.-X. J. Org. Chem. 1999, 64, 670-674, showed that in the Ullmann reaction for amine synthesis 1,10-phenanthroline added at 3.5% with 3.5% cuprous chloride gave a significant rate acceleration to the reaction. A variety of other ligand studies can be found in the literature, including, for example, Rao, H. et al Chem. Eur. J. 2006, 12, 3636-3646; Wang, B.-A. et al Chinese J. Chem. 2006, 24, 1062-1065; Ma, D. and Cai, Q. Org. Lett. 2003, 5, 3799; Cristau, H.-J. et al Org. Lett. 2004, 6(6), 913-916; Ghosh, R. and Samuelson, A. G. New J. Chem. 2004, 28, 1390-1393. Some of the ligands mentioned include a variety of pyridine-based structures, dimethylglycine (an amino acid), 2,2,6,6-tetramethylheptane-3,5-dione, imidazoles, etc. One of the ligands, dimethylglycine (DMG) has not been used in the synthesis of polymers or oligomers.

Aryl ether oligomers and process for making aryl ether oligomers


An image forming apparatus including:                an electrophotographic photoreceptor;        a non-contact charger located close to the electrophotographic photoreceptor, charging the electrophotographic photoreceptor;        an irradiator irradiating the electrophotographic photoreceptor to form an electrostatic latent image thereon;        an image developer developing the electrostatic latent image with a toner to form a toner image on the electrophotographic photoreceptor; and        a transferer transferring the toner image onto a transfer material,        wherein the electrophotographic photoreceptor comprises:                    an electroconductive substrate;            a charge generation layer located overlying the electroconductive substrate;            a charge transport layer located overlying the charge generation layer; and            a crosslinked charge transport layer, located overlying the charge transport layer,            wherein the crosslinked charge transport layer is formed by hardening a radical polymeric monomer having three or more functional groups without a charge transport structure and a radical polymeric compound having one functional group with a charge transporting structure.

1. Field of the Invention
The present invention relates to an electrophotographic image forming apparatus and a process cartridge for use in electrostatic copiers and laser printers, etc.
2. Discussion of the Background
Organic photoreceptors are mostly used in image forming apparatus using electrophotographic process because of having many advantages of being more low-cost, less toxicity, easier-to-coat, etc. than inorganic photoreceptors having been vacuum-evaporated with selenium. Particularly, the organic photoreceptors wherein a charge generation layer and a charge transport layer are layered on an electroconductive substrate are mostly used.
However, the organic photoreceptor is liable to be abraded when repeatedly used, which causes deterioration of the charge potential and photosensitivity thereof and damages of the surface thereof, resulting in background fouling and deterioration of image density of the resultant images. Therefore, improvement of the abrasion resistance and scratch resistance of the organic photoreceptor is desired.
Further, the improvement of the abrasion resistance of the photoreceptor is essential because of the recent higher-speed of electrophotographic apparatus, smaller diameter of the photoreceptor with downsizing of the apparatus, and further full-colorization and free maintenance thereof. Therefore, it is most essential for the organic electrophotographic photoreceptor to produce high-quality images and have high durability.
Various materials are added into the charge transport layer to improve property of the surface of the photoreceptor and durability thereof.
Japanese Laid-Open Patent Publications Nos. 10-198053 and 10-301303 disclose that an electrophotographic photoreceptor including an epoxy compound and a hindered amine or phenol compound having a specific constitution in its photosensitive layer has high durability of not changing electrical properties such as charge potential and residual potential, and not changing sensitivity and image quality without swollen letters and blurred images.
Japanese Laid-Open Patent Publication No. 10-198053 and 10-301303 disclose that an electrophotographic photoreceptor including a polytetrafluoroethylene powder as a lubricant and 4,4-diphenyl-1,1-di(P-di-lower-alkyl-substituted amino phenyl)-butadiene having a formula (C6H5)2(C6H5P—NR2)2 in a surface layer of its photosensitive layer as a charge transport material has durability against abrasion due to friction and scratch, produces high-quality images without blur and has good cleanability without toner adherence to the surface thereof.
Japanese Laid-Open Patent Publication No. 2002-139859 discloses that an electrophotographic photoreceptor including an electroconductive substrate, a photosensitive layer thereon and a protective layer including a filler thereon, wherein the photosensitive layer includes an organic sulfuric compound and the protective layer includes both a hindered amine constitution and a hindered phenol constitution, does not increase the residual potential, does not produce poor images such as blurred images, and stably produce high-quality images for long periods.
However, any of these conventional technologies are insufficient in terms of simultaneous pursuit of higher-quality image and higher durability.
For example, the polytetrafluoroethylene powder disclosed in Japanese Laid-Open Patent Publication No. 10-198053 is a polymer having a low surface energy, and is insoluble in a solvent and has poor dispersibility, resulting in difficulty in preparing a photoreceptor having a smooth surface. Although the dispersibility can be improved with a dispersant, light tends to scatter because the resultant coated layer has a small flexibility, resulting in deterioration of latent images and production of blurred images.
In addition, the photoreceptor disclosed in Japanese Laid-Open Patent Publication No. 2002-139859 has good durability, but does not produce such high-quality images as the photoreceptor of the present invention does.
Further, as conventional technologies to improve the abrasion resistance, (1) Japanese Laid-Open Patent Publication No. 56-48637 discloses a hardening binder used in a crosslinked charge transport layer, (2) Japanese Laid-Open Patent Publication No. 64-1728 discloses a charge transport polymer material, and (3) Japanese Laid-Open Patent Publication No. 4-281461 discloses an inorganic filler dispersed in a crosslinked charge transport layer. A photoreceptor using the (1) hardening binder tends to increase the residual potential and produce images having low image density because of poor compatibility of the hardening binder with a charge transport material and impurities such as a polymerization initiator and an unreacted residue. A photoreceptor using the (2) charge transport polymer material has good abrasion resistance, but does not have satisfactory durability. In addition, the charge transport polymer material is difficult to polymerize and purify, and a coating liquid including the charge transport polymer material has high viscosity. A photoreceptor using the (3) inorganic filler has a higher abrasion resistance than a conventional photoreceptor wherein a low-molecular-weight charge transport material is dispersed in an inactive polymer, but tends to increase the residual potential and produce images having low image density because of a charge trap present on the surface of the inorganic filler. In addition, when the inorganic filler and a binder resin form large concavities and convexities on the surface of the photoreceptor, the cleanability hereof deteriorates, resulting in toner filming and distorted images. These technologies of (1), (2) and (3) do not fully satisfy an overall durability including electrical durability, mechanical durability and image durability required for an organic photoreceptor.
Further, in order to improve the abrasion resistance and the scratch resistance of the photoreceptor using the (1) hardening binder, Japanese Patent No. 3262488 discloses a photoreceptor including a hardened polyfunctional acrylate monomer. However, although disclosing that a protection layer thereof includes the hardened polyfunctional acrylate monomer, Japanese Patent No. 3262488 only discloses that a charge transport material may be included therein and does not disclose specific examples thereof. In addition, when a low-molecular-weight charge transport material is simply included in a surface layer, the low-molecular-weight charge transport material is not soluble with the hardened polyfunctional acrylate monomer and the low-molecular-weight charge transport material separates out and becomes cloud in the surface layer, and which causes deterioration of mechanical strength of the resultant photoreceptor.
Further, since the hardened polyfunctional acrylate monomer is reacted in a surface layer including a polymer binder, a three-dimensional network is not fully developed therein and the crosslinking bond density is thin, and therefore the photoreceptor does not have noticeable abrasion resistance.
As an abrasion resistance technology of a photosensitive layer in place of these technologies, Japanese Patent No. 3194392 discloses a method of forming a charge transport layer using a coating liquid formed from a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond and a binder resin. The binder resin improves adhesiveness between a charge generation layer and a hardening charge transport layer, and is considered to lessen an internal stress therein when hardening. In addition, the binder resin has a carbon-carbon double bond and is broadly classified to a binder resin having a carbon-carbon double bond and reactivity with the charge transport material and a binder resin not having a carbon-carbon double bond and reactivity therewith. The photoreceptor has both good abrasion resistance and electrical property, but when the binder resin not having a reactivity with a charge transport material is used, the binder resin has poor compatibility with a hardened material produced by a reaction between the monomer and charge transport material and the crosslinked transport layer has a layer separation therein, and which occasionally causes damages, and adherence of an external additive in a toner and a paper powder on the surface of the photoreceptor. As mentioned, above, a three-dimensional network is not fully developed therein and the crosslinking bond density is thin, and therefore the photoreceptor does not have noticeable abrasion resistance. In addition, the monomer is bifunctional, which is unsatisfactory in terms of the abrasion resistance. Even when the binder resin having a reactivity with a charge transport material, although having more molecular weight, the hardened material has less intermolecular crosslinking bond. Therefore, the resultant photoreceptor does not have a sufficient crosslinking density, and the electrical and property and the abrasion resistance thereof are not satisfactory.
Japanese Laid-Open Patent Publication No. 2000-66425 discloses a photosensitive layer including a hardened positive hole transport compound having two or more chain polymeric functional groups in the same molecule. Although having a high hardness because of its high crosslinking bond density, the photosensitive layer includes a bulky positive hole transport material having two or more chain polymeric functional groups, and a distortion appears in the hardened compound and an internal stress increases to cause a crack on the crosslinked surface layer and a peeling thereof.
Further, Japanese Laid-Open Patent Publication No. 2001-166501 discloses a photosensitive layer including a positive hole transport polymer compound having two or more chain polymeric functional groups in the same molecule, and having a thickness of from 5 to 15 μm. The thickness is limited to stabilize the electrostatic properties of the photoreceptor, such as charge potential and residual potential thereof in addition to the abrasion resistance and scratch resistance thereof. The thickness does not refer to image quality and a relationship thereof with a writing light source is not referred at all.
In order to improve the abrasion resistance, a photosensitive layer or a surface protective layer including an organic silicon binder resin is practically used. However, the organic silicon binder resin has a high hygroscopicity, resulting in deterioration of image quality, such as blurred images due to toner filming and distorted images.
The reason why a photoreceptor producing high-quality images and having high durability is difficult to prepare is considered as follows.
As mentioned above, many trials have been made to realize high abrasion resistance, and the organic photoreceptor has been noticeably improved in its abrasion resistance. However, at the same time, abnormal images such as blurred images have noticeably been produced. This is because a charged product becomes difficult to remove as the abrasion resistance of the photoreceptor improves.
Namely, since a conventional photoreceptor has a low abrasion resistance, the charged product is removed with abrasion even when accumulated on the surface thereof. The blurred image is produced by a blurred electrostatic latent image due to a horizontal movement of a charge because of lowering of the surface resistivity of the photoreceptor. The surface resistivity lowers because ion species (hereinafter referred to as a charged product) produced with ozone and NOx generated when the photoreceptor is charged and atmospheric moisture are accumulated thereon. In addition, as the abrasion resistance is improved, scratches on the surface of the photoreceptor are difficult to remove and the charged products accumulated therein are more difficult to remove.
Further, besides the charged products, the time and number for the surface of the photoreceptor to be exposed stresses such as a charge noticeably increase as the abrasion resistance thereof improves. Therefore, the surface of the photoreceptor occasionally changes in quality due to ionization and bond breaking because of the stress. Although this may not cause blurred images, but the resistivity locally lowers, resulting in expansion of a dot and deterioration of image density gradation. It is not clear whether a moisture accelerates such reactions or is a medium of lowering the resistivity, however, the phenomena noticeably occurs in an environment of high-temperature and humidity. Therefore, it is essential that the photoreceptor has high abrasion resistance and produces high-quality images as well.
As mentioned above, the blurred images are produced by ozone and NOx generated when the photoreceptor is charged, and adherence and accumulation of the charged products thereon. Therefore, the blurred images can be prevented when the ozone, NOx and charged products increase.
Charges for use in the electrophotographic image forming apparatus are broadly classified to non-contact chargers like corona chargers charging the photoreceptor without contacting the photoreceptor, such as a corotron and a scorotron; and contact chargers charging the photoreceptor contacting the photoreceptor, such as a charging roller and a charging brush.
Corona chargers are simple, but generate much ozone and NOx, adversely affects the electrostatic and image properties of the photoreceptor as well as the environment. In addition, the corona chargers are disadvantageous for downsizing the apparatus. Particularly, when installed in an electrophotographic tandem image forming apparatus including plural photoreceptors and chargers, the ozone and NOx are generated more.
On the other hand, the contact chargers such as a charging roller and a charging brush can charge the photoreceptor to have a specified potential with a lower applied voltage, and therefore the ozone and NOx largely decrease. Therefore, the contact chargers have an advantage against the blurred images, and can uniformly charge the photoreceptor. However, contacting the photoreceptor, the charging member thereof is contaminated with a toner and foreign particles adhering thereto, resulting in deterioration of the chargeability of the photoreceptor; the photoreceptor is contaminated with the toner and foreign particles adhering a gain thereto; the abrasion or uneven abrasion of the photoreceptor is accelerated with the contaminated charging member; the foreign particles removability deteriorates because the charging member is pressed against the surface of the photoreceptor; and abnormal images are produced due to a trace of the charging roller on the photoreceptor or a deformation thereof.
A method of locating a charging member close to a photoreceptor can decrease the ozone and NOx as the contact chargers and can reduce the above-mentioned problems of the contact chargers as well because of not directly contacting the photoreceptor, which seems an effective method for a photoreceptor to have higher durability and produce higher quality images. In addition, the charging member in this method is not easily contaminated and easy to remove the foreign particles even when adhered thereto, and therefore the charging member and the photoreceptor have higher durability.
However, the charging member and the photoreceptor need to precisely be located each other, and the charge stability of the photoreceptor tend to rather deteriorate. An AC voltage overlapped with a DC voltage is applied to the charging member to improve the charge stability, which increases the charged products, resulting in production of blurred images. Further, a charging member located close to a conventional photoreceptor wherein a specific outermost layer is not formed on a photosensitive layer, more causes discharge breakdown of the surface of the photoreceptor. Therefore, even when a charging member is located close to a photoreceptor, the photoreceptor does not have higher durability as expected.
In order to realize a downsized and energy-saving electrophotographic image forming apparatus having high durability which does not need a replacement of a photoreceptor and a dehumidifier and producing high-quality images, the abrasion resistance of the photoreceptor needs to be improved and production of blurred images needs to be prevented. In order to prevent production of blurred images, it is essential to prevent generation of ozone and NOx and contamination of a charging member. The charging member located close to a photo receptor seems to be effectively used, however, as mentioned above, the blurred images and the discharge breakdown of the photoreceptor rather increase, and is not effective for producing high-quality images.
Because of these reasons, a need exists for a power-saving and downsized electrophotographic image forming apparatus having a long life and stably producing quality images for long periods.

This patent is subject to a terminal disclaimer.

Image forming apparatus and process cartridge


A computer implemented method, system, and/or computer program product manages capacity in a service-provider system. A software model of a physical service-provider system is created and stored in memory. A parameter for running the software model with real-time metrics from the physical service-provider system as inputs to the software model is established. If the parameter is met, then the software model is run using the real-time metrics from the physical service-provider system as inputs. A pre-determined action, which adjusts capacity in the service-provider system and is prescribed by a specific model output, is established. If the specific model output, which resulted from using the real-time metrics from the physical service-provider system as inputs for running the software model, is output from the software model, then the pre-determined action is executed.

The present disclosure relates to the field of computers, and specifically to the use of computers in providing services. Still more particularly, the present disclosure relates to the use of computers in facilitating service capacity when providing services.
Management of service capacity is often performed through the use of forecasts. These forecasts estimate how much capacity is needed at various points in a process that provides a particular service, and then locks in that capacity. Such forecasts are unable to account for random variability, which often leads to shortage or excess capacity. Furthermore, the longer it takes to adjust service capacity, the longer managers want the forecast horizon to be, which further decreases accuracy of the forecast. Thus, managing capacity based on forecasts is a vicious cycle.
Furthermore, forecast-based capacity management that is range-based (as opposed to the point forecast described above) requires a provider of the service to predict the maximum and minimum demand expected out to a specified time horizon, rather than predicting demand during individual periods within that horizon. The maximum allowable range is usually specified in a service contract with a customer, so neither party can specify an arbitrarily narrow or wide range. Thus, the service provider is obligated to satisfy demand only within the predicted limits, while the customer is obligated to compensate the service provider for excess capacity when demand falls below the minimum forecast. Therefore, both parties (customer and service provider) have an incentive to create an accurate forecast, which is inherently hard to do, so that both parties share the consequences of inaccurate forecasts.

Forecast-less service capacity management

International Business Machines Corporation


The invention relates to an electrical connector element comprising a base part having a socket section to receive a plug-in contact and an insertion part inserted into the socket section for the contacting of a plug-in contact introduced into the socket section.

A connector element of this kind made in two parts is generally known. Whereas the insertion part inserted into the socket section serves for the contacting of a plug-in contact introduced into the socket section, the base part is typically made such that the connector element can be connected to an electrical line. The electrical path from the line to the plug-in contact therefore leads over the base part and the insertion part. In the known connector element, the insertion part and the base part are welded together to establish an electrical connection. The weld connection can e.g. be made in spot-shape at a plurality of positions by a laser welding process,


A pilot operated valve has a main poppet that selectively controls bidirectional flow of fluid between two ports in response to pressure in a control chamber on one side of the main poppet. The main poppet has a pilot orifice that is opened and closed by a pilot poppet. A unique mechanism is provided to compensate for variation of a pressure differential on opposite sides of the pilot orifice. This mechanism has a pair of annular end members between which extends a spring formed by a plurality of helices. Multiple passages with check valves extend through the main poppet to communicate the greatest pressure among the two ports to the control chamber and the lowest pressure among the two ports to the side of the pilot orifice that is opposite the control chamber.

1. Field of the Invention
The present invention relates to pilot operated hydraulic valves, and more particularly to such valves which incorporate mechanisms that compensate for variation of a pressure differential which exists across a pilot orifice.
2. Description of the Related Art
A wide variety of machines have moveable members which are operated by an hydraulic actuator, such as a cylinder and piston arrangement, that is controlled by a hydraulic valve. Traditionally the hydraulic valve was manually operated by the machine operator. There is a present trend away from manually operated hydraulic valves toward electrical controls and the use of solenoid valves. This type of control simplifies the hydraulic plumbing as the control valves do not have to be located near an operator station, but can be located adjacent the actuator being controlled. This change in technology also facilitates computerized control of the machine functions.
Application of pressurized hydraulic fluid from a pump to the actuator can be controlled by a set of proportional solenoid valves of a type described in U.S. Pat. No. 5,878,647. Solenoid operated pilot valves also are well known for controlling the flow of hydraulic fluid and employ an electromagnetic coil which moves an armature in one direction to open a valve. The armature acts on a pilot poppet that controls the flow of fluid through a pilot passage in a main valve poppet. The amount that the valve opens is directly related to the magnitude of electric current applied to the electromagnetic coil, thereby enabling proportional control of the hydraulic fluid flow. Either the armature or another valve member is spring loaded to close the valve when electric current is removed from the solenoid coil.
When an operator desires to move a member on the machine a control lever is operated to send electrical signals to the solenoid valves for the hydraulic actuator, for example a cylinder-piston combination, associated with that machine member. One solenoid valve is opened to supply pressurized fluid to the cylinder chamber one side of the piston and another solenoid valve opens to allow fluid being forced from the opposite cylinder chamber to drain to a reservoir, or tank. By varying the degree to which the solenoid valves are opened, the rate of flow into the associated cylinder chamber can be varied, thereby moving the piston at proportionally different speeds.
Conventional pilot-operated poppet valves are single directional. There is an inlet port and an outlet port of the valve and the pressure at the inlet port is communicated to the pilot control chamber thus enabling the valve to open when the inlet port pressure is greater than the pressure at the outlet port. This enables fluid to flow from the inlet port to the outlet port. Because of this arrangement, the valve can not be used to control the flow of fluid in the reverse direction from the outlet port to the inlet port. In some hydraulic systems, a bidirectional flow is desired to be controlled. To accommodate flow in both direction a second valve connected in a reverse parallel manner to the first valve was required. Therefore, it is desirable to create bidirectional pilot-operated poppet valve.
One type of bidirectional pilot valve has first port that leads to a side of a main poppet and a second port that leads to the nose of the main poppet. Typically the supply line from the pump was connected to the first port. An O-ring seal around the main poppet generally prevents fluid from leaking along the outer surface of the poppet between the first port and a pilot chamber of the valve. However, when the machine was powered down and the pump no longer supplies pressurized hydraulic fluid to the valve. Some leakage occurs past the O-ring seal over time. For example, it is common that over the night or weekends when a construction site is vacant, compressors and other pieces of equipment are stored raised by a front end loader for security reasons. Thus over these prolonged periods of machine non-use, leakage past the valve O-ring seal can result in the stored equipment dropping down. Thus it is desirable to reduce the number of leakage paths through the hydraulic valves.
A bidirectional, pilot-operated control valve has a body with a first port, a second port, and a valve seat between the first and second ports. A main valve poppet selectively engages the valve seat to control flow of fluid between the two ports. A control chamber is formed within the body on a side of the main valve poppet that is remote from the valve seat.
The main valve poppet has a pilot passage which opens into the control chamber through a pilot orifice. A first passage in the main valve poppet provides communication between the first port and the pilot passage, and a second passage creates a fluid path between the second port and the pilot passage. The main valve poppet has a third passage which provides communication between the first port and the control chamber, while a fourth passage forms a fluid path between the second port and the control chamber.
Each of the four passages has a flow control element, such as a check valve, for example, which allows fluid to flow in only one direction through the respective passage. Specifically, a first flow control element in the first passage allows fluid to flow only from the cavity into the first port. A second flow control element in the second passage allows fluid to flow only from the cavity into the second port. A third flow control element in the third passage allows fluid to flow only from the first port into the control chamber. A fourth flow control element in the fourth passage allows fluid to flow only from the second port into the control chamber.
An actuator operates a pilot poppet to selectively open and close the pilot orifice in the main valve poppet. Opening and closing of the pilot orifice produces movement of the main valve poppet with respect to the valve seat and controls the flow of fluid between the first and second ports.
Another aspect of the present invention is a novel mechanism which compensates for the effects of a varying pressure differential across the pilot orifice. This pressure compensating mechanism is associated with the pilot passage of the main valve poppet and is acted on by that varying pressure differentia. In one embodiment, the pressure compensating mechanism includes an end member slidably received in the pilot passage proximate to the control chamber with the pilot orifice extending there through. A spring is formed by a plurality of helices projecting from the first end member through the cavity and engaging the main valve poppet. The spring compresses and expands in response to variation of the pressure differential across the pilot orifice thus moving the pilot orifice to compensate for the effects of the pressure differential variation on the pilot operation of the main valve poppet.

Pilot operated control valve having a poppet with integral pressure compensating mechanism


Embodiments are disclosed that relate to display of filtered data via ordered values. One embodiment provides for filtering a collection of items via a range of ordered values associated with a rule user interface object. Upon receiving an adjustment to the rule interface object which changes the range, the collection is filtered to display selected items corresponding to that updated range. Further, based on a comparison between the updated range and a threshold, display of the rule may be updated to display values associated with a different granularity level.

Sorting through large collections of data, such as catalogs of images, music data, video data, etc., can be tedious and time-consuming. Further, common user interface filtering tools may make it difficult to filter such collections of data based upon desired value ranges. For example, some filters allow a user to search a collection of time-valued items via a calendar object that allows a user to filter by selecting a date on the calendar. However, such filters may not enable a user to filter a collection based on a desired arbitrary range of time values, or based on time value units other than days. Since time values may correspond to various magnitudes (e.g., millennia, centuries, seconds, milliseconds, etc.), it may be particularly difficult to specify a time range on these orders.

Display of filtered data via ordered values


In mass spectrometry, ion optics process a received ion beam into an output ion beam travelling in an output direction and having a spatial distribution in a plane perpendicular to the output direction elongated in one dimension of the plane relative to the other dimension of the plane and defines an axis of elongation thereby. A quadrupole ion optical device comprises first and second pairs of opposing elongated electrodes, receiving the output ion beam travelling along the output direction and defining an acceptance axis in a plane perpendicular to the direction of elongation of the first and second pairs of opposing elongated electrodes. The acceptance axis is an axis on which maximum acceptance of ions to the quadrupole ion optical device is attained. The first and second pairs of opposing elongated electrodes are oriented substantially to match the acceptance axis to the axis of elongation defined by the spatial distribution.

Mass spectrometers using quadrupole ion optical devices are well known. A particular example of such instruments is the triple quadrupole mass spectrometer, typically used for tandem mass spectrometry. This comprises: a first, mass-selective quadrupole device, Q1, a second quadrupole device acting as a collision cell, for fragmentation of ions, Q2; and a third, mass-resolving quadrupole mass analyser, Q3. Many examples of instruments of this type are known, such as the TSQ 8000 ® or TSQ Quantum®, manufactured by Thermo Fisher Scientific, Inc. A further quadrupole device, Q0, is sometimes provided for use as a preliminary mass filter, ion guide or fragmentation cell. This can permit MSn operation.
Each quadrupole device comprises four parallel rods, arranged as two opposing pairs of electrodes. Generally, the pairs of rod electrodes have applied to them opposite phases of radio-frequency (RF) voltage and optionally DC voltage. Mass-selective quadrupoles generally have RF and DC applied to the electrodes, whereas quadrupoles acting as collision cells or ion guides typically have RF only applied. However, certain quadrupole devices may have only static voltages applied to them, for instance for beam shaping or an array of static lenses. The rods can have a circular, elliptical or hyperbolic cross-section. Alternatively, the rods can have a rectangular cross-section and are referred to as flat rod electrodes, in a configuration referred to as a flatapole or square quadrupole. The flat rod electrodes can have bevelled or straight edges. In all cases, the rods are elongated and the ions travel along the direction of rod elongation. Typically the rods in one quadrupole device are orientated in a plane perpendicular to the ions' direction of travel in the same way as those of another quadrupole device.
There are examples of instruments in which the relative orientations of the rods have been varied though. For example, in the TSQ Quantum® instrument, the relative orientation of the rods in the Q1 and Q3 devices is the same but is rotated by 45 degrees with respect to the curved Q2 collision cell. Although such rotational changes have been considered, these have been based on experimental trial and error. Moreover, no optimal approach has been determined and no rationale for such an optimisation has been identified. Thus, improving the performance of the mass spectrometer by setting the relative orientation of the rods in the quadrupole ion optical devices has not reliably been possible.