Organophotoreceptors comprise an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising:

This invention relates to organophotoreceptors suitable for use in electrophotography and, more specifically, to organophotoreceptors having an improved charge transport compound having at least one azine group.
In electrophotography, an organophotoreceptor in the form of a plate, disk, sheet, belt, drum or the like having an electrically insulating photoconductive element on an electrically conductive substrate is imaged by first uniformly electrostatically charging the surface of the photoconductive layer, and then exposing the charged surface to a pattern of light. The light exposure selectively dissipates the charge in the illuminated areas where light strikes the surface, thereby forming a pattern of charged and uncharged areas, referred to as a latent image. A liquid or solid toner is then provided in the vicinity of the latent image, and toner droplets or particles deposit in the vicinity of either the charged or uncharged areas to create a toned image on the surface of the photoconductive layer. The resulting toned image can be transferred to a suitable ultimate or intermediate receiving surface, such as paper, or the photoconductive layer can operate as an ultimate receptor for the image. The imaging process can be repeated many times to complete a single image, for example, by overlaying images of distinct color components or effect shadow images, such as overlaying images of distinct colors to form a full color final image, and/or to reproduce additional images.
Both single layer and multilayer photoconductive elements have been used. In single layer embodiments, a charge transport material and charge generating material are combined with a polymeric binder and then deposited on the electrically conductive substrate. In multilayer embodiments, the charge transport material and charge generating material are present in the element in separate layers, each of which can optionally be combined with a polymeric binder, deposited on the electrically conductive substrate. Two arrangements are possible. In one two-layer arrangement (the xe2x80x9cdual layerxe2x80x9d arrangement), the charge-generating layer is deposited on the electrically conductive substrate and the charge transport layer is deposited on top of the charge generating layer. In an alternate two-layer arrangement (the xe2x80x9cinverted dual layerxe2x80x9d arrangement), the order of the charge transport layer and charge generating layer is reversed.
In both the single and multilayer photoconductive elements, the purpose of the charge generating material is to generate charge carriers (i.e., holes and/or electrons) upon exposure to light. The purpose of the charge transport material is to accept at least one type of these charge carriers, generally holes, and transport them through the charge transport layer in order to facilitate discharge of a surface charge on the photoconductive element. The charge transport material can be a charge transport compound, an electron transport compound, or a combination of both. When a charge transport compound is used, the charge transport compound accepts the hole carriers and transports them through the layer with the charge transport compound. When an electron transport compound is used, the electron transport compound accepts the electron carriers and transports them through the layer with the electron transport compound.
This invention provides organophotoreceptors having good electrostatic properties such as high Vacc and low Vdis.
In a first aspect, an organophotoreceptor comprises an electrically conductive substrate and a photoconductive element on the electrically conductive substrate, the photoconductive element comprising:
a) a charge transport compound having the formula
where R1 and R2 are, independently, hydrogen, an alkyl group, a heteocyclic group, an alkaryl group or an aryl group; X is an aromatic group; Y is an (N,N-disubstituted) arylamine group, such as a (N,N-disubstituted) arylamine group, a carbazole group or a julolidine group; Z is (CH2)m group where m is an integer between 1 and 30 where one or more of the methylene groups is optionally replaced by O, S, Cxe2x95x90O, Oxe2x95x90Cxe2x80x94O, Oxe2x95x90Cxe2x80x94NR3, sulfoxide, sulfate, phosphate, an aryl group, urethane, urea, a NR4 group, a CHR5 group, or a CR6R7 group where R3, R4, R5, R6, and R7 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, a heteocyclic group, an alkaryl group, or an aryl group; and E is an epoxy group; and
(b) a charge generating compound.
The organophotoreceptor may be provided in the form of a plate, a flexible belt, a flexible disk, a sheet, a rigid drum, or a sheet around a rigid or compliant drum. In one embodiment, the organophotoreceptor includes: (a) a photoconductive element comprising the charge transport compound, the charge generating compound, the electron transport compound, and a polymeric binder; and (b) the electrically conductive substrate.
In a second aspect, the invention features an electrophotographic imaging apparatus that comprises (a) a light imaging component; and (b) the above-described organophotoreceptor oriented to receive light from the light imaging component. The apparatus can further comprise a liquid toner dispenser. The method of electrophotographic imaging with photoreceptors containing the above noted charge transport compounds is also described.
In a third aspect, the invention features an electrophotographic imaging process that includes (a) applying an electrical charge to a surface of the above-described organophotoreceptor; (b) imagewise exposing the surface of the organophotoreceptor to radiation to dissipate charge in selected areas and thereby form a pattern of at least relatively charged and uncharged areas on the surface; (c) contacting the surface with a toner, such as a liquid toner that includes a dispersion of colorant particles in an organic liquid, to create a toned image; and (d) transferring the toned image to a substrate.
In a fourth aspect, the invention features a charge transport compound having the general formula (1) above.
The invention provides suitable charge transport compounds for organophotoreceptors featuring a combination of good mechanical and electrostatic properties. These photoreceptors can be used successfully with liquid toners to produce high quality images. The high quality of the imaging system can be maintained after repeated cycling.
Other features and advantages of the invention will be apparent from the following description of the particular embodiments thereof, and from the claims.

Organophotoreceptor with an epoxy-modified charge transport compound having an azine group

Abstract: where R1 and R2 are, independently, hydrogen, an alkyl group, a heterocyclic group, an alkaryl group or an aryl group; X is an aromatic group; Y is an (N,N-disubstituted) arylamine group, such as a (N,N-disubstituted) arylamine group, a carbazole group or a julolidine group; Z is (CH2)m group where m is an integer between 1 and 30 where one or more of the methylene groups is optionally replaced by O, S, Cxe2x95x90O, Oxe2x95x90Cxe2x80x94O, Oxe2x95x90Cxe2x80x94NR3, sulfoxide, sulfate, phosphate, an aryl group, urethane, urea, a NR4 group, a CHR5 group, or a CR6R7 group where R3, R4, R5, R6, and R7 are, independently, H, hydroxyl, thiol, an amine group, an alkyl group, a heterocyclic group, an alkaryl group, or an aryl group; and E is an epoxy group; and

Abstract: (b) a charge generating compound.


A Virtual Subscriber Service (VSS) is a system and method for operators to provide multiple mutually exclusive telephone numbers, each with its own unique plan features, to a subscriber who is associated with a single terminating device. VSS makes it possible for a subscriber to manage communications directed toward any telephone number associated with his telephone as if any one of the telephone numbers were the only number associated with the telephone. Further, in addition to the primary number, a VSS subscriber can originate communications or return missed communications from the virtual telephone numbers associated with his terminating device. More specifically, some embodiments of a VSS involve the use of a pre-paid account associated with a telecommunications service that has a primary destination code as well as a virtual destination code directed toward a common terminating device such as a mobile telephone. Advantageously, embodiments of a VSS provide a telecommunications operator with a system and method that enables a subscriber to have an additional private telephone number, mutually exclusive from a primary telephone number, without purchasing another telephone or purchasing a multi-SIM card.

If you're over thirty years of age, then you probably remember answering machines. What a breakthrough in communications technology! Answering machines became popular among the masses in the early 1980s as just about everyone who subscribed to a telephone service had one of those little black recording devices networked on their landline. Prior to answering machines, when placing a call, a caller was guaranteed one of three experiences: having his call answered, getting a "busy" signal, or listening to endless rings. Answering machines were revolutionary in that their use rendered endless rings as an obsolete feedback. With an answering machine in use, callers were guaranteed that somebody, or something, was going to answer the call.
While many folks, even today, still make use of the answering machine, the technology has long since advanced to what is commonly known as voicemail. Unlike an answering machine, a subscriber to a voicemail service advantageously doesn't have to be physically near his landline in order to listen to a message. Further, the digital nature of a voicemail system affords users access to many features including call forwarding, archiving, remote access, etc. The advantages of modern day voicemail are numerous.
For one to benefit from the convenience of voicemail, prior art requires that a person first subscribe to a telecommunications service. Additionally, in order to subscribe to a telecommunications service, regardless of whether such service includes voicemail or other useful features, prior art dictates that the subscriber must designate some kind of terminating device for that service such as a telephone, a modem, a PDA, a mobile telephone, etc.
Notably, the COMMUNITY MESSAGING SERVICE solution disclosed in the parent application of the present disclosure provides a novel system and method whereby a subscriber may benefit from a telecommunications service without having to designate a terminating device for such service. In addition to the need in the art addressed in the parent application, there is also opportunity for novel advancement in the art of telecommunications services associated with a subscriber's designated terminating device.
As the consuming public became more and more comfortable with the myriad features that may be associated with a subscriber's telephone service (such as voicemail, missed call logs, previously dialed logs, texting, automatic dial back, etc.), service providers, especially cellular service providers, began mixing and matching value added features in an effort to sell service plans as well as the devices, i.e. telephones, that were compatible with those plans. By doing this, if cellular telecommunications service providers intended to maximize market penetration, it worked. According to the CTIA-Wireless Association, a staggering 250 million Americans now subscribe to a cellular-phone service—that's over 80% of the population according to the last U.S. census. Even more eye popping is that the United Nations estimates that over 50% of people worldwide currently have a mobile telephone.
One Consumer, Two Services, Two Numbers, Two Telephones
Notably, as for those 250 million Americans, it's no stretch to say that many actually have multiple telephones. A 2006 USA Today study reported that 16% of telecommunications customers had separate telephones for personal and business use.
An all too common scenario entails a poor soul with multiple telephones on his hip. Inevitably, his employer has outfitted him with a company provided telecommunications service plan, as well as the obligatory telephone that goes along with it, and instructed him that his continued gainful employment depends on his not using the telephone for personal calls. As he's certain that somebody at the corporate office has nothing better to do than to watch the cell telephone bills like a hawk, a person that is probably likewise eager to keep a job, he's reluctantly obliged to also carry a personal telephone. He's one consumer with two service plans (one business and one personal), two telephone numbers (one for each plan) and, inconveniently, two telephones on his hip.
Multiple Consumers, One Service, One Number, One Telephone
The prior art has produced a number of ways to leverage a telecommunications service, in an effort to serve the needs of more consumers. A common telecommunications plan in many households today, for example, operates to provide multiple consumers using a single terminating device with personalized service plan features. Gone are the days when a household had to subscribe to multiple service plans, each plan being associated with a unique destination code (e.g., telephone number), in order for multiple household members to benefit from personalized service plan features such as voicemail.
At one time, if multiple members of a household required a personalized voicemail service, for example, each of those members had to subscribe to a separate telecommunications service and, thus, have a unique telephone number. Consequently, different terminating devices within the same household were designated for each unique telecommunications service such that "Mom and Dad" received calls on the telephone in the kitchen while "Sister and Brother" received calls on the telephone in the den. One advantage to such a scenario is that if the telephone rang in the den, then everyone knew that the calling party was trying to reach Sister or Brother. Another advantage was that any voice message deposited in the voicemail service associated with the telecommunications service directed to the den telephone was invariably intended for a party associated with that terminating device, i.e. Sister or Brother.
The disadvantages of having multiple telecommunications services coming into a single household are numerous. For one, with multiple services come multiple bills, multiple connection charges, and inflexibility as to terminating device placement within the household (for instance, in the above scenario, Mom and Dad could not "take" a telephone call in the den as the telephone jack in the den would be permanently associated with the "Brother and Sister" telephone service). As a result, service providers devised service plans whereby multiple household members could benefit from personalized plan features, such as voicemail, without the need to subscribe to unique service plans. For example, it became common for a single service plan, associated with a single destination code, to have multiple voicemail boxes so that each family member could benefit from a personalized message depository. As such, a calling party who dialed the telephone number for the household was given the option to perhaps "press 1" to leave a message for Dad, "press 2" to leave a message for Mom or "press 3" to leave a message for Sister or Brother. Advantageously, with such plans the benefit of not having a shared voicemail service could be had without subscribing to multiple telecommunications services. Therefore, multiple consumers (Mom, Dad, Brother and Sister) shared one service with one number (the common household telephone number) directed toward one telephone (every terminating device in the household).
One Consumer, One Service, Multiple Numbers, One Telephone
While the multiple consumers, one service, one number, one telephone approach had the advantage of providing multiple consumers, in a single household for example, with the benefits of personalized plan features on a common service, it was not without its disadvantages. For example, even though multiple family members in a single household enjoyed personalized plan features, such as voicemail, the single telephone number associated with the common service plan dictated that the family member targeted for an incoming call could not be readily recognized. Service plan embodiments with "caller ID" features helped in this regard as any family member in the household could check the "caller ID" on a visual display and, perhaps, determine the called family member but there was no way to uniquely direct a calling party to the correct family member. For instance, in a household, regardless of the family member being called, the calling party had to dial the single common destination code associated with the household service and, if no one answered the call, select the voicemail inbox associated with the targeted family member.
To overcome these limitations, service providers devised plans with multiple destination codes. For example, a single telecommunications service plan could be purchased for a household and multiple telephone numbers associated with the single service. As such, a household did not have to designate termination devices for unique service plans because a call placed to any one of the multiple telephone numbers associated with the common household service could be generally directed to all terminating devices in the household. Notably, while "Mom and Dad" could have one telephone number and "sister and brother" another number, all terminating devices within a household were operable to terminate a call placed to either of the associated numbers. To distinguish the destination code to which an incoming call was directed, service providers offered unique "ring patterns" so that the multiple consumers subscribing to the single service plan could readily discern which of the multiple destination codes was being called. Further, by associating unique ring patterns with each telephone number on a household service, devices such as faxes or modems could be configured to automatically "answer" the call based on recognition of the unique ring pattern.
While this one consumer, one service, multiple numbers, one telephone approach provided a means by which multiple unique telephone numbers, and the service features that go along with each, could be directed to common terminating devices associated with a single telecommunications service, many needs remained unfilled. For example, even though multiple numbers could be directed to common terminating devices, the telecommunications service was necessarily associated with a designated "primary" telephone number. For this reason, any call originating from a terminating device associated with the service would be recognized on the receiving end as originating from the primary number. So, in a scenario where "Mom and Dad" have one telephone number and "Sister and Brother" have a different telephone number, any call originating from the household would be associated with only one of the numbers (whichever was designated as primary, presumably Mom's and Dad's) regardless of the party making the call. Further, even though the "caller ID" features may be useful for discerning the source of a missed call, and by extension the targeted party within the household, a review of the "missed call log" derived from the "caller ID" function would provide no means for determining to which of the multiple destination codes the missed call was directed.
One Consumer, Multiple Services, Multiple Numbers, One Telephone
Notably, none of the prior art, taken alone or in combination, provides a subscriber with a means to fully benefit from the features associated with multiple telecommunications services without either requiring multiple terminating devices or that the benefits of a "primary" service be leveraged. For the most part, a subscriber that requires two mutually exclusive services must carry as many terminating devices. Certainly, a subscriber may "forward" calls directed toward the destination code of one service to the terminating device associated with a second service (e.g., forwarding a home telephone service number to a cellular service number), but such methodology does not avoid the consumption of services associated with the second service nor obviate the need for a terminating device to be associated with the first service. Therefore, what is needed in the art is a system and method for associating multiple telecommunications services, each with a unique destination code, feature set and billing practice, with a single terminating device such that a user in possession of the single terminating device may consume the benefits associated with multiple subscribed services without leveraging the benefits of one service against another.


A radio communications device includes a transmitter, a switch, and a measurement circuit wherein the transmitter transmits radio communications at a transmitted power. The switch couples a portion of the transmitted power during spaced apart intervals of time and blocks coupling of the portion of the transmitted power between the spaced apart intervals of time. The measuring circuit measures the coupled portion of the transmitted power during the spaced apart intervals of time. The radio communications device can also include a feedback circuit that maintains the transmitted power at a desired level responsive to the coupled portion of the transmitted power.

Radiotelephone transmitters generally include an automatic gain control loop to maintain a desired transmission power level out of the antenna. Without such a gain control loop, the transmission power might vary as a function of factors such as transmission frequency, battery voltage, and/or temperature.
In particular, a portion of the power generated by the transmitter power amplifier can be coupled through a capacitor to a rectifier where it is converted to a voltage. This voltage can then be digitized and compared to a calibrated digital code at the radiotelephone microprocessor. A control signal from the microprocessor is used to adjust a variable gain amplifier when the digitized voltage is not equal to the calibrated digital code to maintain the desired transmission power.
Because a portion of the power generated by the transmitter is coupled through the feedback loop, however, the efficiency of the transmitter is reduced. Because the power amplifier generates more power than is actually transmitted through the antenna, the battery life may be reduced. A lower coupling capacitance may thus provide lower coupling and higher efficiency. Proper operation of the feedback loop, however, may dictate a certain level of coupling and the resulting inefficiency.
Moreover, a radiotelephone transmitter may operate at one of a plurality of transmission power levels depending on a signal strength desired at the time. For example, radiotelephones according to the IS-136 standard (IS-136 dual-mode dual band radiotelephones) may transmit at one of eight different transmission power levels ranging from 28 dBm to -4 dBm. Choosing a capacitance value for the coupling capacitor, however, may be difficult over this range of transmission power levels. In particular, a lower value coupling capacitance provides lower coupling and thus higher efficiency, but the lower capacitance may couple insufficient power at the lower power levels to maintain operation of the feedback loop. Higher capacitor values may provide sufficient power coupling at lower power levels for operation of the feedback loop, but the reduced efficiency may significantly reduce the radiotelephone battery life.
U.S. Pat. No. 5,363,071 to Schwent et al. discusses a method for varying coupling of a radio frequency signal. This is accomplished by selecting between a first operating mode of the RF coupler having strong coupling, responsive to a first predetermined power level, such that the RF coupler produces a first coupled RF signal responsive to the RF signal and a second operating mode of the RF coupler having weak coupling, responsive to a second predetermined power level, such that the RF coupler produces a second coupled RF signal responsive to the RF signal. The strongly and weakly coupled RF signals, however, may still contribute to undesired transmission inefficiencies.
Furthermore, it may be difficult to provide a cost effective analog-to-digital converter having useful resolution over the range of power levels discussed above. For example, a 32 dB range of output powers may be difficult to measure using a conventional 8 bit analog-to-digital converter. In conventional arrangements, the highest code of the analog-to-digital converter is set at the maximum operating voltage of the converter, and the lowest code is set at ground. Accordingly, there is a voltage range near the supply voltage and ground where the digital code is variable or redundant. For example, if the supply voltage is 3.3V and there is a 300 mV range of uncertainty, the analog-to-digital converter may only be able to reliably convert from 0.3V to 3V providing a dynamic range of: EQU .vertline.x.vertline.=20 log(0.3/3)=20 dB.
For the reasons discussed above, it may be difficult to provide useful feedback at lower power levels. Accordingly, radiotelephones may effectively provide open loop transmit operations at the lower power levels thereby reducing performance thereof. Furthermore, known feedback loops may result in undesired transmission inefficiencies.

Switched sampling systems and methods for monitoring radio transmit power


A method, apparatus and program storage device for providing intelligent rebuild order selection is a storage array is disclosed. The interrelationship of the data on the drives to be rebuilt and the remaining drives in the system is examined. A relative score for a rebuild record to be rebuilt is based upon the manner in which the RAID data is placed on the other drives. The rebuild record with the highest relative risk is identified as the rebuild record to be rebuilt next.

1. Field of the Invention
This invention relates in general to storage systems, and more particularly to a method, apparatus and program storage device for providing intelligent rebuild order selection is a storage array.
2. Description of Related Art
Computer systems are constantly improving in terms of speed, reliability, and processing capability. As a result, computers are able to handle more complex and sophisticated applications. As computers improve, performance demands placed on mass storage and input/output (I/O) devices increase. There is a continuing need to design mass storage systems that keep pace in terms of performance with evolving computer systems.
A Disk array data storage system has multiple storage disk drive devices, which are arranged and coordinated to form a single mass storage system. There are three primary design criteria for mass storage systems: cost, performance, and availability. It is most desirable to produce memory devices that have a low cost per megabyte, a high input/output performance, and high data availability. "Availability" is the ability to access data stored in the storage system and the ability to insure continued operation in the event of some failure. Typically, data availability is provided through the use of redundancy wherein data, or relationships among data, are stored in multiple locations.
There are two common methods of storing redundant data. According to the first or "mirror" method, data is duplicated and stored in two separate areas of the storage system. For example, in a disk array, the identical data is provided on two separate disks in the disk array. The mirror method has the advantages of high performance and high data availability due to the duplex storing technique. However, the mirror method is also relatively expensive as it effectively doubles the cost of storing data.
In the second or "parity" method, a portion of the storage area is used to store redundant data, but the size of the redundant storage area is less than the storage space used to store the original data. For example, in a disk array having five disks, four disks might be used to store data with the fifth disk being dedicated to storing redundant data. The parity method is advantageous because it is less costly than the mirror method, but it also has lower performance and availability characteristics in comparison to the mirror method.
In a virtual storage system, both the Mirror and the Parity method have the same usage costs in terms of disk space overhead as they do in a non-virtual storage system, but the granularity is such that each physical disk drive in the system can have one or more RAID arrays striped on it as well as both Mirror and Parity methods simultaneously. As such, a single physical disk drive may have data segments of some virtual disks on it as well as parity segments of other physical disks and both data and mirrored segments of other virtual disks.
These two redundant storage methods provide automated recovery from many common failures within the storage subsystem itself due to the use of data redundancy, error codes, and so-called "hot spares" (extra storage modules which may be activated to replace a failed, previously active storage module). These subsystems are typically referred to as redundant arrays of inexpensive (or independent) disks (or more commonly by the acronym RAID). The 1987 publication by David A. Patterson, et al., from University of California at Berkeley entitled A Case for Redundant Arrays of Inexpensive Disks (RAID), reviews the fundamental concepts of RAID technology.
There are five "levels" of standard geometries defined in the Patterson publication. The simplest array, a RAID 1 system, comprises one or more disks for storing data and a number of additional "mirror" disks for storing copies of the information written to the data disks. The remaining RAID levels, identified as RAID 2, 3, 4 and 5 systems, segment the data into portions for storage across several data disks. One of more additional disks are utilized to store error check or parity information. Additional RAID levels have since been developed. For example, RAID 6 is RAID 5 with double parity (or "P+Q Redundancy"). Thus, RAID 6 is an extension of RAID 5 that uses a second independent distributed parity scheme. Data is striped on a block level across a set of drives, and then a second set of parity is calculated and written across all of the drives. This configuration provides extremely high fault tolerance and can sustain several simultaneous drive failures, but it requires an "n+2" number of drives and a very complicated controller design. RAID 10 is a combination of RAID 1 and RAID 0. RAID 10 combines RAID 0 and RAID 1 by striping data across multiple drives without parity, and it mirrors the entire array to a second set of drives. This process delivers fast data access (like RAID 0) and single drive fault tolerance (like RAID 1), but cuts the usable drive space in half. RAID 10, which requires a minimum of four equally sized drives in a non-virtual disk environment and 3 drives of any size in a virtual disk storage system, is the most expensive RAID solution and offers limited scalability in a non-virtual disk environment.
A computing system typically does not require knowledge of the number of storage devices that are being utilized to store the data because another device, the storage subsystem controller, is utilized to control the transfer of data to and from the computing system to the storage devices. The storage subsystem controller and the storage devices are typically called a storage subsystem and the computing system is usually called the host because the computing system initiates requests for data from the storage devices. The storage controller directs data traffic from the host system to one or more non-volatile storage devices. The storage controller may or may not have an intermediate cache to stage data between the non-volatile storage device and the host system.
In a computer system employing the drive array, it is desirable that the drive array remains on-line should a physical drive of the drive array fail. If a main physical drive should fail, drive arrays currently have the capability of allowing a spare physical replacement drive to be rebuilt without having to take the entire drive array off-line. Furthermore, intelligent drive array subsystems currently exist which can rebuild the replacement drive transparent to the computer system and while the drive array is still otherwise operational.
When a disk in a RAID redundancy group fails, the array attempts to rebuild data on the surviving disks of the redundancy group (assuming space is available) in such a way that after the rebuild is finished, the redundancy group can once again withstand a disk failure without data loss. Depending upon system design, the rebuild may be automated or may require user input.
After detecting a disk or component failure and during a rebuild of data, regardless of rebuild design, the system remains subject to yet further disk or component failures before the rebuild is complete. In any RAID system, this is significant because the vulnerability of data loss is dependent upon the RAID architecture.
When multiple disk drives require a rebuild of their data from redundant drives, it is possible that another drive containing the redundant data can be lost during the rebuild causing the loss of user data. The risk of losing data when a subsequent drive is lost is related to the manner in which the redundant data is arranged on the drives. Each drive and each RAID on the drive being rebuilt will have a different risk associated with the loss of another drive.
It can be seen then that there is a need for a method, apparatus and program storage device for providing intelligent rebuild order selection is a storage array.

Method, apparatus and program storage device for providing intelligent rebuild order selection


In a known method for the cleaning of SiO2 grain, a fill of particles in a reactor having a vertically oriented center axis will be heated and simultaneously exposed to a treatment gas which is passed at a specified flow velocity from the bottom to the top through the reactor and the fill. To provide on this basis an improved cleaning method and a suitable simple device for it, it is proposed according to the invention and with regard to the cleaning method that a chloric treatment gas will be used which is set to a treatment temperature of at least 1,000xc2x0 C. in the area of the fill, and that the flow velocity is set to at least 10 cm/s. With regard to the device according to the invention for the implementation of the method according to the invention, a gas shower is provided for the gas inlet, the gas shower comprising below the fill a multitude of nozzle openings distributed laterally to the center axis, for introduction of the treatment gas into the fill. The SiO2 grain of naturally occurring raw material and cleaned according to the invention is characterized by an iron content of less than 20 ppb by weight, preferably less than 5 ppb; a manganese content of less than 30 ppb by weight, preferably 5 ppb; a lithium content of less than 50 ppb, preferably 5 ppb; as well as chromium, copper and nickel each with less than 20 ppb by weight, preferably 1 ppb.

This invention concerns a method for cleaning the SiO2 particles, by heating a fill of the particles in a reactor with a vertically oriented center axis and thereby exposing it to a treatment gas which is conducted at a given flow velocity from the bottom to the top through the reactor and the fill.
Furthermore, the invention concerns a device for the implementation of the method according to the invention, comprising a reactor with a vertically oriented center axis for accepting a fill of SiO2 particles, with a gas inlet for feeding a treatment gas into an area of the reactor essentially below the fill, and with a gas outlet for discharging the treatment gas from an area of the reactor above the fill.
Moreover, the invention concerns cleaned SiO2grain from naturally occurring raw material.
From SiO2 particles, quartz glass products are molten for the chemical and optical industry and for the manufacture of optical fibers and semiconductors. There are high requirements on the purity of the quartz glass products. Especially alkaline metals, alkaline earth metals, heavy metals, iron, carbon and free or combined water may have a detrimental effect on the desired properties of the quartz glass products. Correspondingly high are thus the purity requirements for the raw materials of quartz glass products. Quartz glass raw materials within the meaning of this invention are amorphous or crystalline particles, for example SiO2 particles of naturally occurring quartz, or contaminated synthetically produced grains, granulates, or recycling material.
A method for the continued cleaning of quartz powder by means of thermochlorination has been described in EP-A1 737 653. It has been suggested therein to continuously feed the quartz powder to be cleaned, having a mean grain size ranging between 106 xcexcm and 250 xcexcm, into an electrically heated quartz glass rotary furnace in which it will pass in succession through a preheating chamber, a reaction chamber and a gas desorption chamber. In the preheating chamber, the quartz powder is heated to approx. 800xc2x0 C. and is subsequently treated in the reaction chamber at a temperature of about 1,300xc2x0 C. with a gas mixture of chlorine and hydrochloric gas. The alkaline and alkaline earth contaminations of the quartz powder here react with the chloric gas mixture, forming gaseous metal chlorides. The treatment gas and the gaseous reaction products will subsequently be exhausted.
The known cleaning method leads to a significant reduction of alkaline and alkaline earth contaminations in the quartz powder. The purity of the quartz powder can be yet improved even further by repeated passage of the cleaning process. However, in many quartz powder applicationsxe2x80x94such as for example as a starting material for quartz glass components in the use of semiconductor manufacture or for opticsxe2x80x94the purity of the starting materials will be subject to extremely high requirements which cannot be achieved with the known method or only under great expenditure of time, material and cost.
With the known method, the cleaning effect depends on the reaction period of the quartz powder with the chloric gas mixture and on the reaction temperature. At higher temperatures, chlorine reacts faster with the metallic contaminations so that a better cleaning effect would have to be expected with increasing temperatures. However, at high temperatures, agglomerates will form due to the softening of the grain which will interfere with further access of the treatment gas to the surface of the individual grains. The cleaning effect by the treatment gas which primarily acts on the grain surface will thus be reduced. Furthermore, the cleaning effect depends on the dwell period of the quartz powder in the reaction chamber. Coarse grain powder usually passes the reaction chamber faster than fine grain powder. Thus, different purities may result which may even be different within one charge, depending on the temperature, the grain fraction or throughput. This complicates the reproducibility of the known cleaning method.
In the cleaning method according to DD-PS 144 868, fluid quartz sand Is continuously charged from above into a vertically oriented reactor. The quartz sand fill passes the reactor continuously from top to bottom. The quartz sand fill therein passes a heating up zone, a thermochlorination zone and a cooling down zone. To avoid oxygen from penetrating into the chlorination zone and thus to prevent the reformation of the chlorides formed during chlorination into metal oxides, an inert gas or nitrogen gas curtain is produced at the entrance area and at the exit area of the chlorination zone.
Wet chemical treatments are also customary for removal of contaminations on the surface of naturally occurring quartz sand. In such a method as is described for example in U.S. Pat. No. 4,983,370, the quartz sand is pretreatedxe2x80x94prior to the cleaning process by thermochlorinationxe2x80x94first by means of a two-stage flotation process, a magnetic separator and a subsequent caustic treatment in hydrofluoric acid.
A cleaning method and a device for the implementation of the method in accordance with the aforementioned species are known from EP-A 1 709 340. Therein is suggested to continuously feed SiO2 powder, manufactured by means of flame hydrolysis, to a vertically oriented reactor to remove chlorine, and to treat the powder fill in a countercurrent with a gas mixture of water vapor and air which is conducted through the reactor from the bottom to the top. In the area of the fill, the gas mixture has a linear gas velocity ranging between 1 and 10 cm/s and a temperature ranging between 250xc2x0 C. and 600xc2x0 C. The gas flow will flow through the fill forming a so-called xe2x80x9cfluidized bedxe2x80x9d, and the fill will be slightly raised.
It has been shown that the degree of purity of the SiO2 particles such as it is required for use in semiconductor and optical fiber manufacture cannot be achieved by means of the known methods. Especially the contaminations with the chemical elements Li, Na, K, Mg, Cu, Fe, Ni, Cr, Mn, V, Ba, Pb, C, B and Zr cannot be sufficiently removed by means of the known methods.
This invention is accordingly based on the task of providing an improved method for cleaning the SiO2 particles and of also providing a suitable simple device therefor; as well as of specifying SiO2 grain from naturally occurring raw material and cleaned by using the method according to the invention, such grain being particularly suitable especially for the manufacture of semi-finished or finished quartz glass products for semiconductor and optical fibers production.
In view of the method, this task is solved in accordance with the invention such that a chlorous treatment gas is being used thatxe2x80x94in the area of the fillxe2x80x94is adjusted to a treatment temperature of at least 1,000xc2x0 C. and to a flow velocity of at least 10 cm/s.
A chlorous treatment gas is used. Many of the contaminations contained in SiO2 particles react with the treatment gas at temperatures of above 1,000xc2x0 C. to form gaseous metal chlorides or other volatile compounds which can be exhausted from the reactor via the exhaust gas. Aside from a chlorous component, the treatment gas may contain additionally other componentsxe2x80x94such as fluorine, iodine or bromine, inert gases or hydrogen for examplexe2x80x94which are specially suitable for the removal of specific contaminations or for adjustment of specific properties of the SiO2 or for the heat transfer between treatment gas and particles. For economic reasons, free chlorine is undesirable in the treatment gas so that the chlorous component will contain chlorine in a combined but reactive form.
The treatment gas will be passed through the fill at a flow velocity of at least 10 cm/s. This will ensure that gaseous compounds of the contaminations will be removed as fast as possible from the particles and discharged from the reactor. Moreover, due to the fast gas exchange, the SiO2 particles are continuously and fast provided with unspent treatment gas so that the rate of chemical reaction between treatment gas and contaminations is as high as possible. Decisive will here be the flow velocity in the area of the fill. It should here be noted that, with the fill, the free flow cross-section versus the empty reactor will be reduced and the flow velocity accordingly increased. Here, and in the following, xe2x80x9cfillxe2x80x9d is to mean a bulk deposit of still to be cleaned SiO2 particles in the reactor.
In the area of the fill, a treatment temperature of at least 1,000xc2x0 C. is adjusted for the treatment gas. Contaminations can generally be removed from the particles the easier and faster, the higher the treatment temperature. Since contaminations react with the treatment gas on the free surface of the particles, it is required that the contaminations come to the surface. This is done essentially by diffusion. The contaminations show specific diffusion speeds in the SiO2 particles; however, a higher treatment temperature will principally also achieve a higher diffusion speed. Moreover, due to the higher temperature, the speed of reaction between treatment gas and contaminations is increased. However, at very high treatment temperatures, there is the risk that the particles will agglomerate in the fill so that not only the fluidity of the fill will be reduced but also the cleaning effect of the treatment gases will be reduced as well due to fewer surfaces being free. With regard to this, there is an upper limit for the treatment temperature of about 1,400xc2x0 C.
The treatment gas will be adjusted to the treatment temperature. SiO2 particles will be heated up by the treatment gas to the treatment temperature or kept at the treatment temperature. Accordingly, the temperature of the treatment gas is at least as high as that of the particles. Thus will be prevented that gaseous components condense out of the treatment gas and thus will also be prevented a concurrent adsorption or absorption of contaminations on the particles or, respectively, into the particles.
The method is suitable for a batch-wise as well as a continuous cleaning of the particles. Taking into account the specific reaction temperatures for contaminations with Li, Na, K, Mg, Cu, Fe, Ni, Cr, Mn, V, Ba, Pb, C, B and Zr, the purities achievable with the method according to the invention are always in a sub-ppb range.
It has proven particularly advantageous to adjust the temperature of the treatment gas to at least 1,200xc2x0 C. in the area of the fill. The higher the treatment temperature is adjusted in the area of the fill, the easier and faster contaminations can be removed for the reasons above explained in detail. The treatment temperature from which a significant reaction can be observed between a contaminating element and the treatment gas (reaction temperature) is specific to the element. Thus, sodium contaminations for example can already be significantly reduced at temperatures of approx. 1,000xc2x0 C. with the chlorous treatment gas, whereas higher temperatures of at least 1,050xc2x0 C. are more favorable for the removal of lithium contaminations.
Advantageously, the treatment gas is introduced into the fill such that it will lift it by producing a fluidized particle layer (fluidized bed). The treatment gas will largely flow laminarly through the fluidized particle layer. This will achieve a homogeneous gas distribution in the fill so that the particles are homogeneously charged with the treatment gas. Blind spots in the area of the SiO2 particle layer will be avoided as far as possible so that the contaminations are able to react completely and uniformly. This will achieve a cleaning effect by the treatment gas which is done as completely and uniformly as possible. Moreover, due to the fact that the individual particles of the fill are kept moving in the fluidized bed, the risk of sintering of the particles will be reduced so that the treatment temperature can be set higher.
Maintenance of the most laminar flow possible within the fill will be made easier if the treatment gas is already introduced into the fluidized particle layer in the form of the most laminar gas flow possible. This procedure wherein the laminar flow is already produced below the fill of the particles to be cleaned has proved advantageous especially for the removal of lithium contaminations.
A procedure is preferred wherein the treatment gas is heated, prior to its introduction into the fill, to the treatment temperature or to a temperature above the treatment temperature. Here, the treatment gas will expand to a multiple of its volume at normal temperature. The volume increase is concurrent with a corresponding increase of the flow velocity of the treatment gas. This will facilitate the formation of a fluidized particle layer and a largely laminar flow of the treatment gas through the fill. Moreover, due to the preheating of the treatment gas, the above mentioned condensation effects will be avoided. Due to the contact with the somewhat colder SiO2 particles, the treatment temperature in the treatment gas will come about in the area of the fill.
It proved to be particularly advantageous to use pure inorganic hydrochloric gas as the treatment gasxe2x80x94apart from the inert gases. Such treatment gas contains in particular the lowest possible components with an oxidizing effectxe2x80x94such as oxygenxe2x80x94so that the formation of chlorine in the waste gas of the treatment gas can be largely prevented. This will make a chlorine degassing of the waste gas unnecessary so that its disposal or recycling will be simplified. For example gas scrubbers can be done without, such as they are used with the known cleaning processes for chlorine degassing. Advantageously, such hydrochloric gas contains a stoichiometric excess of elementary hydrogen. Excess hydrogen will react with OH groups in or on the SiO2 particles to form water which is carried as water vapor with the gas flow so that the OH content of the particles can be reduced.
It proved to be successful to introduce the treatment gas into the fill by means of a gas shower having numerous nozzle openings below the fill which are distributed laterally to the center axis. Underneath the fill of the particles to be cleaned, the gas shower has nozzle openings which are essentially symmetrically distributed over the cross-section of the fillxe2x80x94viewed in direction of the flowxe2x80x94and from which the treatment gas will flow. Due to the gas flow applied in an area at the start of the fill, the fill is laminarly passed through in a more or less straight line, and a uniform and homogeneous treatment of the particles over the entire fill will be ensured.
Advantageously, the particles are heated to a temperature in the area of the treatment temperature with the exclusion of air and oxygen. With this procedure, any oxygen or air existing in the fill or in the reactor will be replaced by another gas prior to the heating of the particles, for example by an inert gas or by a treatment gas which, apart from contaminations, is free of oxygen and nitrogen. This will prevent that stable combinations of contaminations in the form of nitrides or oxides will be formed at higher temperatures which can no longer be removed subsequently by the treatment gas. Due to the air and oxygen exclusion, a redox reaction with HCl-containing treatment gas is suppressed which can result in the formation of chlorine gas. As already explained further above, the processing or degassing of the treatment gas would then become considerably more expensive.
In a preferred method, the treatment gas is simultaneously used for air sifting of the fill. For many applications, the removal of the fines content of a grain is desirable since the fines may result in fine bubbles of the quartz glass. By adjusting the flow velocity of the treatment gas, this fines content can be defined and removed from the fill and discharged from the reactor. At the same time, a defined grain fraction can thus be obtained.
Advantageously, a first cleaning stage will be provided for the removal of metallic contaminations or their compounds, especially sodium, manganese, potassium and iron contaminations, and a second cleaning stage for the removal of carbon and carbon compounds. During the second cleaning stage, an oxygen-containing gas is charged to the treatment gas; whereas in the first cleaning stage, an oxygen containing gas is avoided as far as possible. Carbon could cause gas inclusions during the melting of particles so that, during the second cleaning stage, carbon is made to react with oxygen to CO or CO2 and will be removed from the fill.
In a particularly economic process, the treatment gas is run in circulation. Here, the waste gas leaving the reactor is regenerated and again charged to the reactor as a treatment gas. For balancing any gas consumption, regeneration may comprise an admixture of fresh, unused treatment gas.
One procedure proved especially favorable where the flow velocity of the treatment gas is adjusted to at least 30 cm/s. Due to the high flow velocity, the gas exchange will be Increased. The advantages explained in detail above, with regard to the discharge of contaminations and high reaction speeds between the treatment gas and the contaminations, will be further promoted by maintaining a fluidized bed of the fill (fluidized particle layer).
With regard to the device, the above specified task is solved in accordance with the invention by the gas inlet comprising a gas shower, havingxe2x80x94below the fillxe2x80x94a multitude of nozzle openings laterally distributed toward the center axis, for introducing the treatment gas in the fill.
Due to the fact that a gas shower is arranged below the fill, a laminar flow can be produced below the fill, and the treatment gas can be introduced into the fill in the form of a gas flow which is as laminar as possible. Thus, maintenance of the most laminar flow possible within the fill will be facilitated.
The gas shower comprises a multitude of nozzle openings distributed laterally to the center axis. The nozzle openings are essentially distributed symmetrically about the center axis and uniformly over the cross section of the fillxe2x80x94seen in the direction of flow. Due to the gas flow designed in such a laminar fashion at the beginning of the fill, the gas will flow laminarly and more or less in a straight line through the fill, and a uniform and homogeneous treatment of the particles over the complete fill will be ensured.
Advantageously, the gas inlet comprises a gas heating device which is arranged before the gas showerxe2x80x94seen in the direction of flow of the treatment gas. Thus, the treatment gas can be heatedxe2x80x94prior to introducing it into the fillxe2x80x94to a temperature of above the treatment temperature. The effect and the special advantages of this procedure are explained above in more detail on the basis of the method according to the invention.
Especially simple in design is a gas heating device which is formed as a heated tubular coil. By means of the tubular coil, the adjustment of the treatment gas to the treatment temperature can be easily realized by adjusting their lengths to the requirements. The length of the tubular coil is commonly in the range of a couple of meters. It can be arranged in a furnace in which the reactor is located as well, and it consists of a high-temperature resistant material, preferably quartz glass.
The gas shower also consists of a temperature resistant material, for example of quartz glass, silicon carbide or a precious metal, such as platinum or a platinum alloy. In the simplest case, the gas shower is designed in the form of a tube provided with nozzle openings. The tube may have a multitude of forms, for example, the form of a spiral. The gas shower may also be designed as a perforated plate or a frit.
Production of a laminar gas flow will be facilitated if the nozzle openings of the gas shower are symmetrically distributed about the center axis of the reactor. For example, the nozzle openings can be uniformly arranged in annular form around the center axis, with adjacent nozzle openings advantageously having the same distance to each other.
A reactor proved to be especially advantageous which is closable on all sides. Thus, the introduction of oxygen or nitrogen and the resulting risk of the formation of chlorine and thermochemically stabile compounds of contaminations, such as nitrides or oxides, will be prevented.
With regard to the SiO2 grain, the above specified task is solved in accordance with the invention by the SiO2 grain of naturally occurring quartz having an iron content of less than 20 ppb by weight, preferably less than 5 ppb by weight; a manganese content of less than 30 ppb by weight, preferably less than 5 ppb by weight; and a lithium content of less than 50 ppb. by weight, preferably less than 5 ppb by weight, as well as a content of chromium, copper and nickel of each less than 20 ppb by weight, preferably less than 1 ppb.
The SiO2 grain according to the invention is manufactured from natural quartz grain or pretreated quartz grain such as for example commercially sold precleaned grain or it is manufactured from granulate, with such quartz grain being cleaned by means of the method according to the invention. The natural SiO2 grain thus manufactured excels by purities which are otherwise only achievable with synthetically manufactured SiO2. It is thus especially suited as a material to be used for the manufacture of high-purity quartz glass. For example for the manufacture of quartz glass crucibles, bars, rods, plates which are used as components or semi-finished products for the semiconductor industry, for optics and optical communications systems.


An image recording apparatus includes a CPU. An image file created by the CPU is stored in a directory which is created on a hard disk and a circularly successive directory number is assigned to. When the number of image files accumulated in a latest directory reaches “450”, the CPU determines a total number of the directories, and if the total number reaches “50”, the CPU erases an oldest directory. Furthermore, when the number of the image files accumulated in the latest directory reaches “900”, the CPU creates a new directory to which the directory number succeeding to that of the latest directory is assigned. In addition, when an arbitrary directory is erased by an operation of an erasing key, the CPU assigns the successive directory number to a remaining directory in order of a creation time.

1. Field of the Invention
The present invention relates to an image recording apparatus applied to a digital camera, for example. More specifically, the present invention relates to an image recording apparatus storing an image signal in a directory having any one of circularly successive predetermined number of identification numbers.
2. Description of the Prior Art
It is appropriate that image files are scattered to a plurality of directories in order to efficiently manage a vast number of image signals recorded on a recording medium. If time information and a circularly successive directory number are assigned to the directory at a time of creating the directory, a latest directory can be specified on the basis of the time information and an oldest directory is specified by the directory number. Furthermore, in a case the directory number has limitations in number, if the oldest directory is erased at a time the directory number is used up, it is possible to reserve the directory number to be assigned to a new directory. Thus, it is possible to hold a new image signal on the recording medium by priority with efficiently utilizing the directory number limited in number.
However, in a case an arbitrary directory is erased, unless the directory is the oldest directory, it is impossible to utilize a directory number lacked by the erasure. This is because when the lacked directory number is assigned to the new directory, the directory number is not successive in order of creating the directory, and therefore, it is difficult to manage the image signal. Accordingly, even if room for assigning the directory number is obtained by erasing the arbitrary directory, the oldest directory has to be erased at a time of creating the novel directory, and therefore, efficiency of using the directory number decreases.


A substrate W having a non-plateable material portion 31 and a plateable material portion 32 formed on a surface thereof is prepared, and then, a catalyst is selectively imparted to the plateable material portion 32 by performing a catalyst imparting processing on the substrate W. Thereafter, a plating layer 35 is selectively formed on the plateable material portion 32 by supplying a plating liquid M1 onto the substrate W. The plating liquid M1 contains an inhibitor which suppresses the plating layer 35 from being precipitated on the non-plateable material portion 31.

Recently, as miniaturization and three-dimension of semiconductor devices are required, it is required to improve processing accuracy by etching when processing the semiconductor devices. As one way to improve the processing accuracy by etching, it is required to improve accuracy of a hard mask (HM) for dry etching which is formed on a substrate.
Patent Document 1: Japanese Patent Laid-open Publication No. 2009-249679
In general, however, there are many restrictions for a material of the hard mask. For example, the material of the hard mask needs to have high adhesivity to a substrate and a resist, needs to have high resistance against a heat treatment, and an etching processing, and, also, needs to be easily removed. For the reason, conventionally, only a limited material such as SiN (silicon nitride) or TiN (titanium nitride) has been used as the material of the hard mask.
In view of this, the present inventors have examined providing a film of SiO2 (silicon oxide) or the like and a film of SiN (silicon nitride) or the like on a substrate; applying a catalyst such as Pd on the substrate to selectively apply the catalyst on the SiN film; and forming a plating layer only on the SiN film by using this catalyst. In this case, as the plating layer formed on the SiN film can be used as the hard mask, it is possible to select various kinds of materials as the plating layer.
Meanwhile, the SiO film on the substrate may have a minute lattice defect, an impurity, or the like. In such a case, the catalyst of Pd or the like may adhere to the lattice defect or the impurity. Accordingly, if the plating processing is performed in this state, the plating layer may be formed on a part of the SiO film as well, which is not intended originally, raising a concern that such an unnecessary plating layer might end up as a defect.

Plating method, plating apparatus and recording medium


A mask pattern is employed for multi-pass printing. The mask pattern is the sum of a first mask pattern, relative to a first location that includes areas wherein dots are to be printed when a density value is smaller than a predetermined value, and a second mask pattern, relative to a second location that includes areas wherein dots are to be printed only when the density value is equal to or greater than the predetermined value. Using multiple scans, up to one dot is printed in the first region, while two dots or more are printed in the second region. With this arrangement, since the first mask pattern, which greatly affects a low-duty image, and the second mask pattern, which greatly affects a high-duty image, can be independently designed, problems that occur with images prepared at individual duties can be coped with by the separate mask patterns.

1. Field of the Invention
The present invention relates to an ink jet printing method and an ink jet printing system for presenting information having a predetermined density on a print medium using a printing agent.
2. Description of the Related Arts
As the information processing apparatuses, such as personal computers, have spread, print apparatuses have been rapidly developed and have become popular as image forming terminals. Of the various types of print apparatuses presently available, ink jet print apparatuses, which to print by ejecting ink through discharge orifices onto printing media such as paper, cloth, plastic sheets and OHP sheets, have extremely superior characteristics, e.g., low-noise, non-impact type printing systems are employed, printing can be performed at a high dot density and at a high speed, color printing can be easily coped with, and prices are low. Today, ink jet print apparatuses constitute the mainstream of the print apparatuses available for personal use.
Continuing, accelerated technological advances in inkjet printing have yielded improvements in image quality, increases in operating speeds and reductions in prices that, taken together, have contributed greatly to the extended use of personal print apparatuses, paralleling the use today of personal computers and digital cameras (including not only self-contained cameras but also integrated components, of apparatuses such as cellular phones, that function as cameras). However, because the print apparatuses are widely used, a personal user demand has arisen for apparatuses which have improved image quality capabilities, and as a consequence, a particularly recent demand has arisen for home printing systems that can easily print pictures having image qualities equivalent to those of silver halide photography.
When an image printed by an ink jet print apparatus is compared with one produced by so-called ordinary silver halide photography, the granularity is viewed as an appropriate problem. Recently, a variety of countermeasures to minimize the granularity have been proposed, and many print apparatuses that incorporate these countermeasures have also been provided. For example, one ink jet print apparatus comprises an ink system that not only has common cyan, magenta, yellow and black ink, but also light cyan and magenta, which have lower densities. With this ink system, when light cyan or magenta is employed in a low density area, the dotted appearance can be minimized. Furthermore, when common cyan and magenta are used for printing in high density areas, greater and smoother tones can be reproduced.
Another method is one whereby, in order to minimize the granularity, a design is provided that reduces each dot size landing on a printing medium. For this method, the technology has been developed for reducing the size of ink volume to be discharged from individual printing elements arranged in a print head. In this case, not only is the size of the ink droplets reduced, but also, an arrangement including a greater number of printing elements is arranged in a higher density, so that a high resolution image can be formed with no decrease in printing speed.
For a personal use ink jet print apparatus, in addition to the acquisition of a high quality image, one almost the equivalent of a photograph, as described above, the apparatus is often desired that can also output general documents, such as text and charts or tables. For such documents, the speed at which printing is performed is more important than the ability to provide an image quality equivalent to that of a silver halide photograph. Therefore, a plurality of printing modes are provided for a general purpose ink jet print apparatus, so that a desired mode can be selected, as needed, by a user (see, for example, Japanese Patent Application Laid-Open No. 1-281944(1989)).
However, not all technological developments provided for the improvement of image quality can harmoniously coexist with a need to reduce costs and with printing modes for which the focus is on high speed printing. For example, for an ink jet print apparatus, for which the amount of ink discharged (hereinafter referred to as the discharged volume) by a printing element cannot be changed, in order to minimize the granularity, all the ink droplets discharged through the individual printing elements in a print head are defined as small droplets, having a fixed volume. The dots printed using the determined discharge volume are arranged at a preferred dot density, so that a desired density can be obtained (see, for example, the specification of Japanese Patent No. 03184744). Therefore, as the discharged volume is reduced, the printing dot density required to obtain a desired print density is increased, and accordingly, the configuration means and the required data processing are fixed, to a degree, and are complicated. Therefore, in a mode in which high speed printing is expected, the printing performed must depend on the configuration means and the data processing method described above, if a desired density is to be obtained. As a result, it is difficult for an appropriate density to be provided at a satisfactory printing speed.

Ink jet printing method and ink jet printing system


An output terminal of a photoelectric conversion element included in the photoelectric conversion device is connected to a drain terminal and a gate terminal of a MOS transistor which is diode-connected, and a voltage Vout generated at the gate terminal of the MOS transistor is detected in accordance with a current Ip which is generated at the photoelectric conversion element. The voltage Vout generated at the gate terminal of the MOS transistor can be directly detected, so that the range of output can be widened than a method in which an output voltage is converted into a current by connecting a load resistor, and so on.

A number of photoelectric conversion devices used for detecting an electromagnetic wave are generally known, and for example, photoelectric conversion devices having sensitivity from ultra violet rays to infrared rays are collectively referred to as optical sensors. Among them, an optical sensor having sensitivity in a visible light region with a wavelength of 400 to 700 nm is particularly referred to as a visible light sensor, and a large number of visible light sensors are used for devices which need illuminance adjustment, on/off control, or the like depending on human living environment.
In some display devices, ambient brightness of the display device is detected to adjust display luminance. This is because unnecessary electric power of the display device can be reduced by detecting ambient brightness by an optical sensor and obtaining appropriate display luminance. For example, examples of display devices which have an optical sensor for adjusting luminance include mobile phone and computer.
In addition, as well as the ambient brightness of the display device, luminance of the backlight of a display device, in particular, a liquid crystal display device is also detected by an optical sensor to adjust luminance of a display screen.
In an optical sensor, a photoelectric conversion element such as a photodiode or the like is used for a light sensing part, and an output current of the photoelectric conversion element is amplified in an amplifier circuit For example, a current mirror circuit is used as the amplifier circuit of the optical sensor (for example, see Reference 1: Japanese Patent No. 3444093).

Photoelectric conversion device and electronic device provided with the photoelectric conversion device

Semiconductor Energy Laboratory Co., Ltd.


A circuit is arranged to limit the rate of change in fan speed control signals. The control system includes a controller that produces a nonlinear (or piecewise linear approximation of a nonlinear function) fan speed control signal. The nonlinear fan speed control signal can reduce unnecessarily large changes in the fan speed and provide a greater degree of control at higher temperatures. Linear changes in the speed of a fan often result in audible noises that are undesirably distracting. Controlling the fan by using nonlinear exponential step sizes advantageously reduces the apparent fan noise by linearly varying the amount of fan noise in approximately equal percentages between each programmed fan speed. The step sizes are nonlinear with respect to temperature change and are linear with respect to fan noise.

The present invention relates generally to control systems, and more particularly to providing nonlinear control of a fan for temperature controlled systems.
Intelligent system temperature control is an important consideration for many electronic systems, including systems such as personal computers. Such systems can be designed to vary the speed of a fan to regulate the temperature of the system. The speed of the fan is controlled by measuring a temperature of the system, selecting a desired fan speed in accordance with the measured temperature, and signaling the fan driver with a signal that conveys the target fan speed. Changes in the fan speed result in audible changes in the sound generated by the fan.
The present invention is directed towards a nonlinear fan control system for limiting the rate of change in fan speed control signals. The control system includes a controller that produces a nonlinear (or piecewise linear approximation of a nonlinear function) fan speed control signal. The nonlinear fan speed control signal can reduce unnecessarily large changes in the fan speed and provide a greater degree of control at higher temperatures. Linear changes in the speed of a fan often result in audible noises that are undesirably distracting. Controlling the fan by using nonlinear exponential step sizes advantageously reduces the apparent fan noise by linearly varying the amount of fan noise in approximately equal percentages between each programmed fan speed. The step sizes are nonlinear with respect to temperature change and are linear with respect to fan noise.
A more complete appreciation of the present invention and its improvements can be obtained by reference to the accompanying drawings, which are briefly summarized below, to the following detailed description of illustrated embodiments of the invention, and to the appended claims.


A field effect transistor for microwave and millimeter wave frequencies includes a plurality of feeding points on a gate finger extending on a substrate, an airbridge wiring structure which connects adjacent feeding points with each other, and a gate pad beyond the source and drain electrodes connected with the gate finger through the airbridge. The relatively wide gate connection reduces gate resistance. The gate connection does not cross the source and drain electrodes, reducing capacitance. The reduced resistance and capacitance significantly improve the high frequency noise figure.

FIG. 3 shows, in cross-section, the main part of a fundamental field effect transistor (hereinafter referred to as an FET). In FIG. 3, reference numeral 1 designates a semiconductor substrate. Conductive layers or insulating layers required for operation are disposed on the substrate 1. A gate electrode 2 is provided to modulate the current flowing from the drain electrode 3 to the source electrode 4 in response to an electrical signal applied thereto.
One use of such an FET is as a low noise amplifier. The characteristic which is most important in this use is the noise figure (hereinafter referred to as NF) which indicates the noise level generated by the FET itself. Since the noise figure deteriorates with an increase in frequency, in order to use the FET at a high frequency, such as in microwave or millimeter wave frequencies, a variety of steps have to be taken. The minimum noise figure (NF.sub.min) is usually represented by the following formula: ##EQU1## where gm is transconductance, R.sub.s is source series resistance, R.sub.g is gate resistance, C.sub.gs is gate-to-source capacitance, K.sub.f is a constant, and f is the frequency. As is understood from the above formula, to reduce NF, an increase in the transconductance gm and reductions in the gate-to-source capacitance C.sub.gs, gate source resistance R.sub.s, and gate resistance R.sub.g are required.
To reduce C.sub.gs and increase gm, shortening of the gate length (L.sub.g) of the device is most effective. In GaAs MESFETs or HEMTs (high electron mobility transistor) which have been recently devised as low noise elements used at microwave frequencies, the L.sub.g is usually quite short, less than 0.5 micron. However, the shortening of L.sub.g invites a reduction of gate cross-sectional area and an increase of R.sub.g. For example, in the rectangular gate electrode as shown in FIG. 3, there is a limit to the reduction of NF. The value of NF.sub.min at 12 GHz is limited to about 1 dB.
The reduction of R.sub.g is accomplished by production of a T-shaped gate electrode as shown in FIG. 4. In FIG. 4, a gate electrode 2 has a T-shaped cross-section and the gate length L.sub.g, which is the length of the gate in contact with the semiconductor substrate 1, is quite narrow, i.e., 0.2 micron. However, the upper portion of the gate electrode has a larger cross-sectional area, thereby suppressing the increase in R.sub.g. By such a construction, an element having an NF.sub.min of 0.5 to 0.6 dB is realized, showing that the reduction of R.sub.g is quite effective. However, the production of T-shaped gate electrodes requires patterning of L.sub.g to about 0.2 micron, which is not easy.
FIG. 5 shows a plan view of an FET. Reference numeral 2a designates a gate finger and reference numeral 2b designates a gate pad. Reference numerals 3 and 4 designate a drain electrode and a source electrode, respectively. Reference numeral 5 designates a feeding point for applying a voltage to the gate finger 2a. FIGS. 3 and 4 correspond to cross-sections taken along lines III--III and IV--IV in FIG. 5. The external connection is made by adhering a wire to the gate pad 2b.
Usually, an FET element is constructed as shown in FIG. 5, and a voltage is applied from the two feeding points 5 to the gate finger 2a, and the length of the gate finger 2a (the entire gate width is W.sub.g) is electrically divided by four, thereby resulting in four unit gate widths, Z, each of which is equal to W.sub.g /4. There is a relationship between the gate resistance R.sub.g, entire gate width W.sub.g, and unit gate width (which is a feeding length from respective feeding points) Z, EQU R.sub.g .varies.W.sub.g Z.sup.2.
For a fixed gate width W.sub.g, it is useful to increase the number of feeding points 5 to shorten the unit gate width Z.
By increasing the number of feeding points, the increase of R.sub.g can be suppressed. However, if the number of feeding points is simply increased by a construction as shown in FIG. 5, the number of gate pads 2b is also increased and many external connections have to be made. Furthermore, an increase in the number of large area gate pads would unfavorably invite an increase in the floating capacitance.
FIGS. 6(a) and 6(b) show an example in which the number of feeding points is increased without increasing the number of gate pads. FIG. 6(a) shows a plan view and FIG. 6(b) shows a cross-sectional schematic view taken along line VIb--VIb of FIG. 6(a). The number of feeding points is five and the unit gate width Z is W.sub.g /10, whereby the R.sub.g is significantly reduced. The gate pad 2b and the feeding points 5 are connected by the gate wiring 6, and this gate wiring 6 crosses the source electrode 4. Of course, the gate wiring 6 and the source electrode 4 are electrically isolated from each other. However, care has to be taken not to increase the capacitance therebetween. Therefore, the gate wiring 6 is arranged bridging the source electrode 4. Such a structure is usually called an airbridge. Because air has a smaller dielectric constant than an insulating film, such as SiO.sub.2, it is possible to reduce the capacitance with an airbridge. The example shown in FIGS. 6(a) and 6(b) is disclosed in the IEICE Technical Report, Volume 88, Number 60, pages 39-44 (1988) and, in such a construction, an improved NF.sub.min of 0.5 to 0.6 dB is realized without using a gate having a T-shaped cross-section.
Another construction shown in FIGS. 7(a) and 7(b) reduces the gate resistance (European Patent 0,203,225, IEEE Transactions on Electron Devices, Volume ED-32, Number 12, December 1985, pages 2754-2759, "Airbridge Gate FET For GaAs Monolithic Circuits"). This construction employs an airbridge structure similar to that shown in FIG. 5. In this construction, electric power is not supplied at a point but along the entirety of the gate width. When such a construction is used, the R.sub.g can be reduced to a negligible value which is quite useful for low noise properties. However, the gate electrode 6 and the source electrode 4 cross each other over a large area, and eve if an airbridge structure is used, the increase in gate capacitance causes a large problem.
As discussed above, a variety of structures have been proposed to reduce the gate resistance in order to produce a low noise FET. However, the accompanying production processes are very difficult to apply in industrial fabrication or produce an increase of gate capacitance which unfavorably influences the FET characteristics. These problems result in an insufficient performance improvement.


A fuel cell component integrates an attachment member 5 and a gasket 1 by using an adhesive 3. Both side portions of the gasket in the width direction of the gasket are provided with adhesive application regions W1 where the adhesive 3 is interposed, and a center portion in the width direction of the gasket is provided with an adhesive non-application region W2 where the adhesive 3 is not interposed so as to ensure an attachability.

This section provides background information related to the present disclosure which is not necessarily prior art.
A fuel cell generates electricity using a principle of taking electricity during the process of obtaining water from a reaction of hydrogen and oxygen (air). This fuel cell includes a fuel cell stack including a plurality of layers of cells each made up of: an electrolyte membrane letting hydrogen ions pass therethrough; and two separators sandwiching the electrolyte membrane therebetween. The separators forming a cell are required to have a sealing property to block hydrogen and oxygen and a conductive property enabling electricity to be taken.
Since hydrogen, oxygen, strong acids, hydrofluoric acids, coolant water and the like are used in the stack, a gasket is incorporated therein so as to seal these substances. The gasket has to deal with such various sealing objects including hydrogen, oxygen, strong acids, hydrofluoric acids and coolant water, and an adhesive also is required to be resistant to these sealing objects.
The gasket has to have durability for a very long time, and the adhesive also is required to keep attachability over a long time period, i.e. to have durable strength. Deterioration in the attachability causes a problem of gasket displacement due to a pressure in the cell, for example.
Meanwhile, as illustrated in FIG. 4, a fuel cell constituting component is known, which is obtained by applying an adhesive 3 on the entire bottom surface of a gasket 1 so as to chemically bond an attachment member 5 such as an impregnation integral molding carbon plate, a metal plate, or a resin film, thus integrating the attachment member 5 and the gasket 1.
As illustrated in FIG. 5, however, when the adhesive 3 is applied on the entire surface, a sealing object S on a stack inside A might enter into an interface between the gasket 1 and the attachment member 5, and cleave chemical bonding between rubber and the adhesive, and such deterioration might diffusively spread so as to attack the continuous adhesive application layer progressively, thus leading to an increasing tendency of deterioration in attachability.
Further, as illustrated in FIG. 6, there is another problem that the adhesive interface undergoes a force similar to stress generated at the bottom surface of the gasket 1 during compression of the gasket 1, so that a load is generated upon bonding the gasket 1 to the adhesive 3. This might lead to not only the deterioration in attachability but also a reason for rupture H of the gasket 1 itself as illustrated in FIG. 7.


A docking system includes: a station including: a light emitter comprising light emitting elements arranged in a circular arc form so as to cause optical axes of light generated from the light emitting elements to pass through a curvature center of the circular arc; and a self-moving robot including: a body part having a circular arc part being substantially the same in curvature radius as the circular arc of the station; a movement mechanism attached to the body part to move the body part and capable of causing the body part to conduct on-the-spot rotation at a curvature center of the circular arc part; light receivers attached to the body part to receive a light signal from the light emitter; a direction detector detecting a direction in which the light signal is emitted; and a controller controlling the movement mechanism to move the body part in the direction detected by the direction detector.

1. Field of the Invention
The present invention relates to a self-moving robot and a docking system including the self-moving robot and a station docked with the self-moving robot.
2. Related Art
As a conventional system of docking between the self-moving robot and the station for the purpose of supplying power to the self-moving robot, conducting wired information communication or collecting dust, a system for conducting docking by laying a guidance cable that emits an electromagnetic wave, guidance tape that reflects light, or the like on a route of the self-moving robot and detecting the station by means of movement of the self-moving robot along the route, or by installing the station along a wall of the room and detecting the station by means of movement of the self-moving robot along the wall is known. In these systems, it is necessary to previously provide a track using the guidance tape or the like or utilize a different structure such as the existing wall.
Furthermore, a method of providing the self-moving robot with a map recognizing function, recognizing the current position of the self-moving robot on the basis of the rotation quantity of a gyro provided in the self-moving robot or a wheel of the self-moving robot is also known. In this method, position deviations are accumulated because of the deviation of the wheel or drifts of the gyro. According to the moving distance, therefore, the recognized position deviates from the actual position. This results in a problem that the self-moving robot cannot reach an accurate target position.
As a method for solving this problem, a method of installing various markers on the route to guide the self-moving robot has been devised.
In JP-A 2002-215235 (KOKAI), a guidance apparatus that guides the self-moving robot by using a light emitter which applies light to a light receiver formed of a plurality of light receiving elements disposed on the left and right of the self-moving robot, toward a target position is described.
In Japanese Patent No. 2821375, a method of fixing and disposing position correction means using infrared rays, transmitting and receiving specific code signals by using infrared rays between the position correction means and the self-moving robot, and measuring the isolation distance between them by using distance sensing means is described.
As for a self-moving robot described in JP-A 2005-63184 (KOKAI), a light emission device which emits a specific identification code as a light signal is disposed on the route and position coordinates are corrected by using a distance measuring unit which calculates the distance from the light emission device on the basis of the identification code of the light signal is described. They are effective as means that calculates the deviation of its own position and guides the self-moving robot without accumulating the deviation, and effective to guide the self-moving robot to the vicinity of the docking system. However, they do not conduct positioning (inclusive of the attitude) for final docking.
As for positioning for docking, it is described in JP-A 2001-525567 (KOKAI) to provide at least two light emitters having different directivities, guide the self-moving robot to the vicinity of the station by using a light emitter having a wide directivity, and further conduct positioning for docking by using a light emitter having a narrow directivity.
For uniquely determining the position and attitude of the self-moving robot at the time of docking, accurate guidance becomes necessary. In JP-A 2001-525567 (KOKAI), therefore, guidance is conducted by the light emitter having the narrow directivity. If the light emitter having the narrow directivity is used, however, there is a problem that the guidable range becomes narrow. In JP-A 2001-525567 (KOKAI), therefore, the different light emitter having the wide directivity is installed. In the guidance using the light emitter having the wide directivity, it is necessary to install the light emitter on the center of on-the-spot rotation of the self-moving robot. Therefore, there is a problem that the light emitter must be disposed solidly on a structure that is disposed over the self-moving robot.


A method and apparatus for processing out-of-order processing of packets is described. In one embodiment, the method includes receiving a packet, which is in an original position relative to other packets; and attempting, by a primary processing unit, to classify and process the packet. The method also includes determining whether the packet was completely classified and processed by the primary processing unit; and upon determining that the primary processing unit completely classified and processed the packet, bypassing a secondary processing unit. The method also includes transmitting the packet onto a network, the packet being transmitted in its original position relative to the other packets.

1. Field of the Invention
The invention relates to the field of networking. More specifically, the invention relates to the processing packets.
2. Background of the Invention
Packet processing may be implemented using a general purpose processor which performs all algorithms for delivering packets to their destination. However, more advanced packet processors separate "routing" from "switching." The term "routing" used herein refers to determining the best path for packets to travel through a network from their source to their destination, while the term "switching" used herein refers to moving packets from one port to another, within a network element.
FIG. 1 shows a block diagram illustrating a prior art computer network. In this prior art figure, the backbone network 108 is made up of core routers 104a-b. The edge routers 102a-f connect the core routers 104a-b of the backbone network 108 to local area networks 106a-f.
Core routers 104a-b, as compared to edge routers 102a-f, typically perform a lesser amount of packet processing. Typically, when packets reach core routers, advanced packet processing has been completed, leaving only basic packet processing for the core routers. For example, core routers mainly switch packets to other core routers on the backbone network; thus, performing only basic packet header modifications. Because core routers 104 mostly perform only basic packet processing, they can transmit packets faster than edge routers 102.
In contrast, edge routers 102a-d perform more complicated packet processing because they impose the backbone network's traffic constraints and other traffic control requirements on the local area networks 106a-f. For example, a backbone network owner may sell access to a backbone network to different local users. In FIG. 1, the local users make up the local area networks 106a-f. Local users may purchase access packages that allow access to the backbone network 108 at different levels of bandwidth. Edge routers 102 must enforce these bandwidth constraints upon the local area networks 106. For example, if a user's plan allows a user to transmit 10,000 Megabits per second to the backbone network 108, the edge routers 102 must determine whether the user is exceeding its bandwidth constraints, and drop packets accordingly. Because edge routers perform a wide variety of packet processing, they typically have greater processing capabilities, but lower packet throughput than core routers.
FIG. 2 shows a block diagram illustrating a prior art switching unit. The switching unit represents a set of one or more chips on a line card used for processing packets in a network element. The prior art switching unit of FIG. 2 includes classifier circuitry 202, which is connected to a processor queue 204. The processor queue 204 is connected to a processor array 206, which is connected to an output queue 212. The processor array executes software including packet processing software 208 and reorder buffering software 210.
In the prior art switching unit 200, incoming packets enter the classifying circuitry 202, wherein they are classified according to levels of needed processing. The packets are passed to the processor queue 204 before entering the processor array 206. In the processor array 206, the packet processing software 208 processes the packets according to their classifications. For example, a packet classified as a multicast packet is processed according to multicast procedures. Because packet processing may complete out-of-order for an ordered group of packets, and because it is advantageous to maintain order for groups of packets, the reorder buffering software 210 reorders the packets. The packets are transmitted to the output queue 210 and out of the switching unit 200.
A limitation of this prior art switching unit is that all packets travel the same path through the switching unit, regardless of the amount processing needed by each packet. As a result, this prior art switching unit has the disadvantage of sending packets needing very little processing through the processor array 206 and the software reorder buffer 208.

Method and apparatus for implementing a switching unit including a bypass path


A chirp waveform generator for producing a chirp waveform ƒ(t)=sin (t2 modulus m) where modulus m is represented by n submoduli and/or factored submoduli m1-mn. Sequence generators generate digital sequence values representative of sequences of quadratic residues for each submoduli and/or factored submoduli m1-mn. Sine and cosine digital-to-analog converters (DACs) connected to the sequence generators receive the digital sequence values for each submoduli and/or factored submoduli m1-mn and produce sequences of corresponding analog sine and cosine signals. An analog processor including adders and multipliers connected to the DACs combines the sine and cosine signals to produce the chirp waveform. The argument (t2 modulus m) is an implemented phase argument that approximates a desired phase argument (πrt2). Programmable inputs on the sequence generators enable control over waveform parameters including starting phase, ramp rate and frequency.

A classical chirp sinusoid is represented simply byƒ(t)=sin(πrt2)  Eq. (1)where the time origin is chosen to be the point where the chirp waveform passes through zero frequency. The derivative of the phase argument is 2πrt, indicating that the constant r expresses a phase acceleration, or frequency ramp rate in frequency per unit time. If r is large, then the function ƒ(t) appears very non-sinusoidal, moving in instantaneous frequency from DC to high frequency in a short time. However, if r is small, then the function ƒ(t) appears to approximate a sinusoid of constant frequency for relatively-long time periods.
The function ƒ(t) may equally well be written asƒ(t)=sin(πrt2 mod 2π)  Eq. (2)where mod represents a modulus operation. If the angular units of the argument are changed to those where the quantity
  2  rrepresents a full period, and furthermore the time unit is taken to be that of the sampling frequency ƒs, then the function can be written as the sampled functionƒt=sinm(t2 mod m)  Eq. (3)where in general m=2ƒs2/r, representing the angle which corresponds to 2π radians. The integer t represents the tth sampling instant, and the modified function sinm( ) indicates that the units of the argument are such that the modulus m represents 2π radians.
It is assumed that r and ƒs are such that m is an integer. For a fixed ƒs, this assumption amounts to a quantization constraint in the frequency ramp rate r. For typical applications, choices for r remain practically continuous even with fixed ƒs. The choices are fully continuous if ƒs need not be exactly fixed at design time. For a frequency ramp rate r in the range of 1 MHz per microsecond, played at a typical sample rate of 1 Gs/s, m=2,000,000. The next available integral choice for m (2,000,001) would give a ramp rate slightly smaller than 1 MHz per microsecond (smaller by 1 part in 2 million).
The phase of the sinusoid function, a=t2 mod m, in equation 3, generates a sequence of integers. Each of these integers is called a quadratic residue of m. Some older textbooks such as Charles Varden Eynden, Number Theory: An Introduction to Proof, International Textbook Company, 1970, further stipulate that a quadratic residue must also be coprime with the modulus m. The terms "coprime" and "relatively prime" both describe a set of numbers that share no common factors. However, the broader, more-modern definition is used herein. Number theory texts have many pages devoted to the properties of this deceptively simple function. It is, for example, relatively easy to find a given an integer t. However, it is nontrivial, in the general case, to find t when a is given (or even to determine whether there exists such a t).
For example, if m=16, then the generated sequence of quadratic residues begins with 0,1,4,9,0,9,4,1,0,1,4,9,0,9,4,1, . . . . The sequence appears to repeat indefinitely. Only 4 quadratic residues appear to exist modulo 16, when one might expect to observe as many as 16.
Conventional high speed chirp waveform signal generators are complex and have relatively high power requirements. There is a need for improved chirp waveform signal generators. In particular, there is a need for chirp waveform signal generators that operate at high speed with relatively low power requirements.

Digital chirp waveform generator and method

Mayo Foundation for Medical Education and Research