A capacitor device includes a capacitor Q constituted by a lower electrode (12) formed an a substrate (10), a dielectric film (14), and an upper electrode (16); an insulating film (18) covering the capacitor Q; a first contact hole (18a) formed in the insulating film (18) on a connection portion (16a) of the upper electrode (16); an electrode pad (20) for preventing a diffusion of solder, formed in the first contact hole (18a); and a solder bump (22) electrically connected to the electrode pad (20), and the upper electrode (16) has a protrusion portion (16a) protruding from the dielectric film (14), and is connected to the first contact hole (18a) on the protrusion portion (16a).

In recent years, in semiconductor devices such as digital LSIs including a microprocessor, a tendency of decrease in a power supply voltage is developed because of influence of a speeding up of an operation speed and a low power consumption. In such a LSI, its operation power supply voltage tends to be unstable when its impedance changes rapidly. In order to stabilize the power supply voltage and to decrease high frequency noises, a decoupling capacitor is inserted between a power supply voltage line of the LSI and a ground line thereof.
Particularly, since a stable operation in a higher frequency (GHz) range is required in a high speed operation digital LSI, an improvement in performance of the decoupling capacitor such as high frequency followership is desired. Therefore, a capacitor device having a thin film capacitor structure in which a technology capable of reducing a thickness of a dielectric film to increase capacitor capacity is introduced has been devised. Such a thin film capacitor is manufactured based on a thin film process for forming a metallic film, oxide and the like on a base substrate such as silicon. Since a microprocessing is possible in this thin film processes, a capacitor having a low inductance structure can be obtained.
FIGS. 1A to 1E and FIGS. 2A to 2D are section views showing an example of a method of manufacturing a capacitor device having a thin film capacitor according to prior art. In the conventional method of manufacturing a capacitor device, as shown in FIG. 1A and FIG. 1B, after a silicon substrate 100 is prepared, a lower electrode 102 for a capacitor formed of a metallic film is formed on the silicon substrate 100. Thereafter, as shown in FIG. 1C and FIG. 1D, a dielectric film 104a is grown on the lower electrode 102, and then a metallic film 106a for an upper electrode is grown on the dielectric film 104a.
Next, as shown in FIG. 1E, by etching predetermined portions of the upper electrode metallic film 106a and the dielectric film 104a, an upper electrode 106 for a capacitor and a dielectric film 104 for a capacitor are formed, and a connection portion 102a of the lower electrode 102 are exposed. Thus, a capacitor Q constituted by the lower electrode 102, the capacitor dielectric film 104 and the upper electrode 106 is formed.
Subsequently, as shown in FIG. 2A, a protection insulating film 110 having first and second contact holes 110a and 110b respectively is formed on a connection portion 106x of the upper electrode 106 and the connection portion 102a of the lower electrode 102. This protection insulating film 110 is formed of a polyimide resin film having a thickness of, for example, about 3 μm, and the first and second contact holes 110a and 110b are formed by performing exposure and developing processings for predetermined portions of the polyimide resin film.
Next, as shown in FIG. 2B, a barrier metallic film 112a is formed on the protection insulating film 110 and in the first and second contact holes 110a, 110b. This barrier metallic film 112a is formed of a lamination film, and is formed by being buried in the first and second contact holes 110a and 11b by a sputtering method and electroplating.
Subsequently, as shown in FIG. 2C, the barrier metallic film 112a is patterned by photoetching, whereby an electrode pads 112 are left in the first and second contact holes 110a, 110b. These electrode pads 112 are formed as a metallic plug, which has a thickness of about 3 μm or more, in the first and second contact holes 110a, 110b.
Next, a resist film (not shown) having an opening portion is formed on the electrode pads 112, and a solder bump is formed in the opening portion by electroless plating, followed by removing the resist film. Thereafter, as shown in FIG. 2D, the solder bump undergoes a thermal treatment (wet back) to reflow, whereby solder bumps 116 are obtained.
In the above described manner, the solder bump 116s are formed in a state where the solder bumps 116 are electrically connected to the connection portion 106x of the upper electrode 106 and the connection portion 102a of the lower electrode 102 through the plug-shaped electrode pads 112 having a thickness of about 3 μm or more.
The above described electrode pads 112 are called an under bump metal (UBM), and have a function to prevent that solder in the solder bumps 116 diffuse into films constituting the capacitor Q disposed under the bumps 116 to react therewith during the foregoing thermal treatment (wet back) process.
As described above, the conventional art adopts the structure in which the first contact holes 110a are formed on the upper electrode 106 of the portion where the lower electrode 102, the dielectric film 104 and the upper electrode 106 are laminated, and in which the upper electrode 106 is electrically connected to the solder bumps 116 through the electrode pads 112 (UBM) formed in the first contact holes 110a.
Since the above described electrode pads 112a (UBM) need to have a comparatively thick film of thickness of about 3 μm or more to prevent the diffusion of the solder, tensile stress is apt to occur just below the electrode pads 112a due to influences of the electrode pads 112a. Therefore, there is a problem that peeling is prone to occur along an interface between the upper electrode 106a and the dielectric film 104a below the electrode pads 112a.
Furthermore, since the polyimide resin film having a comparatively high coefficient of thermal expansion (40 to 50 ppm/° C.) is generally used as the protection insulating film 110, tensile stress occurs near the upper electrode 106a below the protection film 110. Therefore, there is a problem that adhesion of the upper electrode 106a and the dielectric film 104a becomes weak and peeling is prone to occur along an interface between them.

Capacitor device and method of manufacturing the same


An image forming apparatus includes developing devices, each of which contains a developing agent of a single color therein; a photosensitive member; a latent image forming device that forms a latent image on the photosensitive member, the latent image being developed into a visible image on the photosensitive member, the visible image being made of developing agent images of each color using the developing agent of the single color supplied by each of the developing devices; and an image receiver member that contacts the photosensitive member and receives the developing agent images of each color formed on the photosensitive member sequentially and electrically. A transfer bias for transfer developing agent images from the photosensitive member to the image receiver member is set lower for the first developing agent image that is transferred than a transfer bias for transferring a second developing agent image.

1. Field of Invention
The invention relates to an image forming apparatus that forms multi-color developing agent images by transferring and overlaying developing agent images of each color sequentially from a photosensitive member to an image receiver member
2. Description of Related Art
There exists image forming apparatuses that form a color image (i.e., a color laser printer). Typically, in a color laser printer, a plurality of color toners, which are constituents of a color image, are used to form a toner image of each color on a photosensitive drum. The toner image of each color is electrically transferred and successively overlaid on an image receiver member such as a sheet of paper and an intermediate transfer belt Thereby, a multi color toner image is formed on the image receiver member. Japanese Patent Application No. 2001-166556 discloses a tandem color laser printer which has a plurality of process units that include a plurality of colors.

Image forming apparatus for a color laser printer for transferring a higher transfer efficiency on a recording sheet on the upstream side of the imaging forming process


The present invention provides a process for preparing ball-type desulfurizer with high sulfur capacity, comprising the following steps: placing initial balls in a rolling equipment; wetting the surface of the initial balls with an aqueous solution of an organic binder; then alternately adding non-crystalline iron oxide hydroxide and the aqueous solution of the organic binder to gradually form small balls of non-crystalline iron oxide hydroxide with high sulfur capacity and different diameters; and adjusting the shape of the small balls and then roasting or naturally drying the small balls. In the desulfurizer prepared by this method, the initial balls constitutes 0.98 wt %-9.03 wt % of the desulfurizer, the non-crystalline iron oxide hydroxide constitutes 90.29 wt %-98.62 wt % of the desulfurizer, and the organic binder constitutes 0.58 wt %-0.89 wt % of the desulfurizer. The present invention solves the problems that the desulfurizer with high sulfur capacity in the prior art has a high binder content and poor water resistance and diffusion performance, and provides a process for preparing a desulfurizer with high sulfur capacity, wherein a desulfurizer with high sulfur capacity and low binder content, good water resistance, good diffusion performance can be prepared.

It is well known that, large amounts of hydrogen sulfide are emitted from many industries including sewage treatment, paper making, petroleum processing, fertilizer manufacturing, chemical fiber manufacturing as well as some chemical raw materials manufacturing industries. These hydrogen sulfide emissions will not only cause environmental pollution, but also easily lead to poisoning and deactivation of catalyst. Therefore, reducing the emissions of hydrogen sulfide of industrial production becomes one of the major problems that need to be resolved in the industrial production in the present world.
Currently, in order to reduce the impact of hydrogen sulfide on the environment and industrial production effectively, a variety of desulfurizers for hydrogen sulfide are developed in the market, including iron based desulfurizer, manganese oxide-based desulfurizer, solid alkali desulfurizer, liquid desulfurizer and activated carbon desulfurizer, etc., among which iron based desulfurizer is mostly used. The iron based desulfurizer comprises one or more substances selected from the group of ferroferric oxide, ferric oxide and hydrous ferric oxide as the main active components.
U.S. Pat. No. 5,102,636A discloses a compound desulfurizer which is consisted of iron oxide and iron. These iron based desulfurizers are usually of low sulfur capacity which only reaches 27% as the highest, thus the desulfurization effect is not ideal. Besides, most of the iron-based desulfurizers do not have high mechanical strength and good water resistance, and have low pressure drop across beds. So when being applied in working conditions for desulfurization of hydrous refinery gas, shifted gas and liquefied petroleum gas and so on, those iron-based desulfurizers are easily pulverized or hardened due to soaking in water, resulting in a too large pressure drop across beds and even causing block of towers. A patent application of this applicant published as CN101584962A provides a high-strength iron oxide hydroxide desulfurizer and preparation method thereof, wherein a carrier, non-crystalline iron oxide hydroxide and an organic binder were mixed to yield a mixture which then was extruded to produce a extrudate desulfurizer. The desulfurizer is consisted of 50 to 95% non-crystalline iron oxide hydroxide, 0 to 45% carrier and 5-50% organic binder, and has the characteristics such as high sulfur capacity and high mechanical strength. However, the organic binder may be dissolved in water, so when the content of the organic binder is high, the desulfurizer is easily expanded and deformed when contacting with water, and the water resistance of the desulfurizer is poor. In addition, the clearances in the desulfurizer materials are small due to extrusion molding, which is not conducive to the spread of the flue gas therein. Therefore, the desulfurizer in the prior art has the shortcomings such as poor water resistance and poor diffusion performance due to the high content of organic binder and extrusion molding. If reducing the binder content, molded desulfurizer products with high mechanical strength and high anti-extrusion property cannot be obtained by the preparation method for desulfurizer of the prior art.

Process for preparing ball-type desulfurizer with high sulfur capacity and product thereof

BEIJING SJ ENVIRONMENTAL PROTECTION AND NEW MATERIAL CO., LTD.


The present invention is a method and apparatus for integrating a personal communication system with a cable television plant. A set of radio antenna devices (RAD) are connected to the cable plant. The RADs provide frequency conversion and power control of signal received from the cable plant for wireless transmission to the remote units. The RADs also provide power control and frequency conversion of wireless signals received from the remote units for transmission by the RADs onto the cable plant. In addition to the functions of standard base stations and centralized controller, the CATV base station must also compensate for gain variations in the cable plant. The downstream power control is regulated by a RAD reference signal which can be hidden within the CDMA signal for maximum efficiency. The upstream power control is regulated by an upstream gain reference signal which is individually transmitted by each RAD on the upstream link. The architecture of the present invention lends itself to a great deal of flexibility. Each RAD can operate as either an element of a distributed antenna or a base station sector unto itself. The function of each RAD as distributed antenna or as sector can be remotely programmed from the headend processor. Thus the capacity density of the system can be changed to accommodate the changing traffic density. The flexibility also is important at system deployment. When the system is deploy, the entire system may feed only one sector at the base station thus reducing the start-up cost of implementing a system. As system traffic increases, more resources can simply be added at the headend to provide more capacity.

I. Field of the Invention
The present invention relates to communication systems, particularly to a method and apparatus for performing handoff between two sectors of a common base station.
II. Description of the Related Art
In a code division multiple access (CDMA) cellular telephone, wireless local loop or personal communications system, a common frequency band is used for communication with all base stations in a system. The common frequency band allows simultaneous communication between a remote unit and more than one base station. Signals occupying the common frequency band are discriminated at the receiving station through the spread spectrum CDMA waveform properties based on the use of a high speed pseudonoise (PN) code. The high speed PN code is used to modulate signals transmitted from both the base stations and the remote units. Transmitter stations using different PN codes or PN codes that are offset in time produce signals that can be separately received at the receiving station. The high speed PN modulation also allows the receiving station to receive several instances of a common signal from a single transmitting station where the signal has traveled over several distinct propagation paths due to the multipath characteristics of the radio channel or purposefully introduced diversity.
The multipath characteristics of the radio channel create multipath signals which travel several distinct propagation paths between the transmitting station and the receiving station. One characteristic of a multipath channel is the time spread introduced in a signal that is transmitted through the channel. For example, if an ideal impulse is transmitted over a multipath channel, the received signal appears as a stream of pulses. Another characteristic of the multipath channel is that each path through the channel may cause a different attenuation factor. For example, if an ideal impulse is transmitted over a multipath channel, each pulse of the received stream of pulses generally has a different signal strength than the other received pulses. Yet another characteristic of the multipath channel is that each path through the channel may cause a different phase on the signal. For example, if an ideal impulse is transmitted over a multipath channel, each pulse of the received stream of pulses generally has a different phase than the other received pulses.
In the radio channel, the multipath is created by reflection of the signal from obstacles in the environment, such as buildings, trees, cars, and people. In general the radio channel is a time varying multipath channel due to the relative motion of the structures that create the multipath. For example, if an ideal impulse is transmitted over the time varying multipath channel, the received stream of pulses would change in time, location, attenuation, and phase as a function of the time that the ideal impulse is transmitted.
The multipath characteristics of a channel can cause signal fading. Fading is the result of the phasing characteristics of the multipath channel. A fade occurs when multipath vectors act destructively, yielding a received signal that is smaller than either individual vector. For example if a sine wave is transmitted through a multipath channel having two paths where the first path has an attenuation factor of X dB (decibels), a time delay of .delta. with a phase shift of .THETA. radians, and the second path has an attenuation factor of X dB, a time delay of .delta. with a phase shift of .THETA.+.pi. radians, no signal would be received at the output of the channel.
In narrow band modulation systems such as the analog FM modulation employed by conventional radio telephone systems, the existence of multiple path in the radio channel results in severe multipath fading. As noted above with a wideband CDMA, however, the different paths may be discriminated at the receiving station in the demodulation process. The discrimination of multipath signals not only greatly reduces the severity of multipath fading but provides an advantage to the CDMA system.
In an exemplary CDMA system, each base station transmits a pilot signal having a common PN spreading code that is offset in code phase from the pilot signal of other base stations. During system operation, the remote unit is provided with a list of code phase offsets corresponding to neighboring base stations surrounding the base station through which communication is established. The remote unit is equipped with a searching element that allows the remote unit to track the signal strength of the pilot signal from a group of base stations including the neighboring base stations.
A method and system for providing a communication with a remote unit through more than one base station during the handoff process are disclosed in U.S. Pat. No. 5,267,261, entitled "MOBILE ASSISTED SOFT HANDOFF IN A CDMA CELLULAR TELEPHONE SYSTEM," issued Nov. 30, 1993 assigned to the assignee of the present invention. Using this system, communication between the remote unit and the end user is uninterrupted by the eventual handoff from an original base station to a subsequent base station. This type of handoff may be considered as a "soft" handoff in that communication with the subsequent base station is established before communication with the original base station is terminated. When the remote unit is in communication with two base stations, the remote unit combines the signals received from each base station in the same manner that multipath signals from a common base station are combined.
In a typical macrocellular system, a system controller may be employed to create a single signal for the other end user from the signals received by each base station. Within each base station, signals received from a common remote unit may be combined before they are decoded and thus take full advantage of the multiple signals received. The decoded result from each base station is provided to the system controller. Once a signal has been decoded it cannot be `combined` with other signals. Thus, the system controller must select between the plurality of decoded signals produced by each base station with which communication is established by a single remote unit. The most advantageous decoded signal is selected from among the base station and the other signals are simply discarded.
Remote unit assisted soft handoff operates based on the pilot signal strength of several sets of base stations as measured by the remote unit. The Active Set is the set of base stations through which active communication is established. The Neighbor Set is a set of base stations surrounding an active base station comprising base stations that have a high probability of having a signal strength of sufficient level to establish communication. The Candidate Set is a set of base stations having a pilot signal strength at a sufficient signal level to establish communication.
When communications are initially established, a remote unit communicates through a first base station and the Active Set contains only the first base station. The remote unit monitors the pilot signal strength of the base stations of the Active Set, the Candidate Set, and the Neighbor Set. When a pilot signal of a base station in the Neighbor Set exceeds a predetermined threshold level, the base station is added to the Candidate Set and removed from the Neighbor Set at the remote unit. The remote unit communicates a message to the first base station identifying the new base station. A cellular or personal communication system controller decides whether to establish communication between the new base station and the remote unit. Should the cellular or personal communication system controller decide to do so, the cellular or personal communication system controller sends a message to the new base station with identifying information about the remote unit and a command to establish communications therewith. A message is also transmitted to the remote unit through the first base station. The message identifies a new Active Set that includes the first and the new base stations. The remote unit searches for the new base station transmitted information signal and communication is established with the new base station without termination of communication through the first base station. This process can continue with additional base stations.
When the remote unit is communicating through multiple base stations, it continues to monitor the signal strength of the base stations of the Active Set, the Candidate Set, and the Neighbor Set. Should the signal strength corresponding to a base station of the Active Set drop below a predetermined threshold for a predetermined period of time, the remote unit generates and transmits a message to report the event. The cellular or personal communication system controller receives this message through at least one of the base stations with which the remote unit is communicating. The cellular or personal communication system controller may decide to terminate communications through the base station having a weak pilot signal strength.
The cellular or personal communication system controller upon deciding to terminate communications through a base station generates a message identifying a new Active Set of base stations. The new Active Set does not contain the base station through which communication is to be terminated. The base stations through which communication is established sends a message to the remote unit. The cellular or personal communication system controller also communicates information to the base station to terminate communications with the remote unit. The remote unit communications are thus routed only through base stations identified in the new Active Set.
Because the remote unit is communicating with the end user though at least one base station at all times throughout the soft handoff process, no interruption in communication occurs between the remote unit and the end user. A soft handoff provides significant benefits in its inherent "make before break" communication over conventional "break before make" techniques employed in other cellular communication systems.
In a cellular or personal communication telephone system, maximizing the capacity of the system in terms of the number of simultaneous telephone calls that can be handled is extremely important. System capacity in a spread spectrum system can be maximized if the transmission power of each remote unit is controlled such that each transmitted signal arrives at the base station receiver at the same level. In an actual system, each remote unit may transmit the minimum signal level that produces a signal-to-noise ratio that allows acceptable data recovery. If a signal transmitted by a remote unit arrives at the base station receiver at a power level that is too low, the bit-error-rate may be too high to permit high quality communications due to interference from the other remote units. On the other hand, if the remote unit transmitted signal is at a power level that is too high when received at the base station, communication with this particular remote unit is acceptable but this high power signal acts as interference to other remote units. This interference may adversely affect communications with other remote units.
Therefore, to maximize capacity in an exemplary CDMA spread spectrum system, the transmit power of each remote unit within the coverage area of a base station is controlled by the base station to produce the same nominal received signal power at the base station. In the ideal case, the total signal power received at the base station is equal to the nominal power received from each remote unit multiplied by the number of remote units transmitting within the coverage area of the base station plus the power received at the base station from remote units in the coverage area of neighboring base stations.
The path loss in the radio channel can be characterized by two separate phenomena: average path loss and fading. The forward link, from the base station to the remote unit, operates on a different frequency than the reverse link, from the remote unit to the base station. However because the forward link and reverse link frequencies are within the same general frequency band, a significant correlation between the average path loss of the two links exists. On the other hand, fading is an independent phenomenon for the forward link and reverse link and varies as a function of time.
In an exemplary CDMA system, each remote unit estimates the path loss of the forward link based on the total power at the input to the remote unit. The total power is the sum of the power from all base stations operating on the same frequency assignment as perceived by the remote unit. From the estimate of the average forward link path loss, the remote unit sets the transmit level of the reverse link signal. Should the reverse link channel for one remote unit suddenly improve compared to the forward link channel for the same remote unit due to independent fading of the two channels, the signal as received at the base station from this remote unit would increase in power. This increase in power causes additional interference to all signals sharing the same frequency assignment. Thus, a rapid response of the remote unit transmit power to the sudden improvement in the channel would improve system performance. Therefore, it is necessary to have the base station continually contribute to the power control mechanism of the remote unit.
Remote unit transmit power may also be controlled by one or more base stations. Each base station with which the remote unit is in communication measures the received signal strength from the remote unit. The measured signal strength is compared to a desired signal strength level for that particular remote unit. A power adjustment command is generated by each base station and sent to the remote unit on the forward link. In response to the base station power adjustment command, the remote unit increases or decreases the remote unit transmit power by a predetermined amount. By this method, a rapid response to a change in the channel is effected and the average system performance is improved. Note that in a typical cellular system, the base stations are not intimately connected and each base station in the system is unaware of the power level at which the other base stations receive the remote unit's signal.
When a remote unit is in communication with more than one base station, power adjustment commands are provided from each base station. The remote unit acts upon these multiple base station power adjustment commands to avoid transmit power levels that may adversely interfere with other remote unit communications and yet provide sufficient power to support communication from the remote unit to at least one of the base stations. This power control mechanism is accomplished by having the remote unit increase its transmit signal level only if every base station with which the remote unit is in communication requests an increase in power level. The remote unit decreases its transmit signal level if any base station with which the remote unit is in communication requests that the power be decreased. A system for base station and remote unit power control is disclosed in U.S. Pat. No. 5,056,109 entitled "METHOD AND APPARATUS FOR CONTROLLING TRANSMISSION POWER IN A CDMA CELLULAR MOBILE TELEPHONE SYSTEM," issued Oct. 8, 1991, assigned to the Assignee of the present invention.
Base station diversity at the remote unit is an important consideration in the soft handoff process. The power control method described above operates optimally when the remote unit communicates with each base station through which communication is possible. In doing so, the remote unit avoids inadvertently interfering with communications through a base station receiving the remote unit's signal at an excessive level but unable to communicate a power adjustment command to the remote unit because communication is not established therewith.
A typical cellular or personal communication system contains some base stations having multiple sectors. A multi-sectored base station comprises multiple independent transmit and receive antennas. The process of simultaneous communication with two sectors of the same base station is called softer handoff. The process of soft handoff and the process of softer handoff are the same from the remote unit's perspective. However, the base station operation in softer handoff is different from soft handoff. When a remote unit is communicating with two sectors of the same base station, the demodulated data signals of both sectors are available for combination within the base station before the signals are passed to the cellular or personal communication system controller. Because the two sectors of a common base station share circuitry and controlling functions, a variety of information is readily available to sectors of a common base station that is not available between independent base stations. Also two sectors of a common base station send the same power control information to a remote unit (as discussed below).
The combination process in softer handoff allows demodulated data from different sectors to be combined before decoding and thus produce a single soft decision output value. The combination process can be performed based on the relative signal level of each signal thus providing the most reliable combination process.
As noted above, the base station can receive multiple instances of the same remote unit signal. Each demodulated instance of the arriving signal is assigned to a demodulation element. The demodulated output of the demodulation element is combined. The combined signal is decoded. The demodulation elements, instead of being assigned to a single sector, may be assigned to a signal from any one of a set of sectors in the base station. Thus, the base station may use it resources with high efficiency by assigning demodulation elements to the strongest signals available.
Combining signals from sectors of a common base station also allows a sectorized base station to make a single power adjustment command for remote unit power control. Thus, the power adjustment command from each sector of a common base station is the same. This uniformity in power control allows flexible handoff operation in that sector diversity at the remote unit is not critical to the power control process. Further details of the softer handoff process are disclosed in U.S. patent application Ser. No. 08/144,903, filed Oct. 30, 1993, entitled "METHOD AND APPARATUS FOR PERFORMING HANDOFF BETWEEN SECTORS OF A COMMON BASE STATION," assigned to the assignee of the present invention. Further information on the benefits and application of softer handoff are disclosed in U.S. patent application Ser. No. 08/144,901, filed Oct. 30, 1993, entitled "METHOD AND APPARATUS FOR REDUCING THE AVERAGE TRANSMIT POWER FROM A SECTORIZED BASE STATION" and U.S. patent application Ser. No. 08/316,155, filed Sep. 30, 1994 entitled "METHOD AND APPARATUS FOR REDUCING THE AVERAGE TRANSMIT POWER OF A BASE STATION" each of which is assigned to the assignee of the present invention.
Each base station in the cellular system has a forward link coverage area and a reverse link coverage area. These coverage areas define the physical boundary beyond which base station communication with a remote unit is degraded. In other words, if a remote unit is within the base station's coverage area, the remote unit can communicate with the base station, but if the remote unit is beyond the coverage area, communications are compromised. A base station may have single or multiple sectors. Single sectored base stations have approximately a circular coverage area. Multi-sectored base stations have independent coverage areas that form lobes radiating from the base station.
Base station coverage areas have two handoff boundaries. A handoff boundary is defined as the physical location between two base stations where the link would perform the same regardless of whether the remote unit were communicating with the first or second base station. Each base station has a forward link handoff boundary and a reverse link handoff boundary. The forward link handoff boundary is defined as the location where the remote unit's receiver would perform the same regardless of which base station it was receiving. The reverse link handoff boundary is defined as the location of the remote unit where two base station receivers would perform the same with respect to that remote unit.
Ideally these boundaries should be balanced, meaning that they should have the same physical location. If they are not balanced, system capacity may be reduced as the power control process is disturbed or the handoff region unreasonably expands. Note that handoff boundary balance is a function of time, in that the reverse link coverage area shrinks as the number of remote units present therein increases. Reverse link power, which increases with each additional remote unit, is inversely proportional to the reverse link coverage area. An increase in receive power decreases the effective size of the reverse link coverage area of the base station and causes the reverse link handoff boundary to move inward toward the base station.
To obtain high performance in a CDMA or other cellular system, it is important to carefully and accurately control the transmit power level of the base stations and remote units in the system. Transmit power control limits the amount of self-interference produced by the system. Moreover, on the forward link, a precise level of transmit power can serve to balance the forward and reverse link handoff boundaries of a base station or a single sector of a multi-sectored base station. Such balancing helps to reduce the size of the handoff regions, increase overall system capacity, and improve remote unit performance in the handoff region.
Before adding a new base station to the existing network, the forward link (i.e. transmit) power and the reverse link (i.e. receive) signal power of the new base station are both approximately equal to zero. To begin the process of adding the new base station, an attenuator in the receive path of the new base station is set to a high attenuation level, creating a high level of artificial noise receive power. An attenuator in the transmit path is also set to a high attenuation level, which in turn causes a low transmit power level. The high level of artificial noise receive power results in the reverse link coverage area of the new base station being very small. Similarly, because the forward link coverage area is directly proportional to the transmit power, the very low transmit power level and the forward link coverage area is also very small.
The process then continues by adjusting the attenuators in the receive and transmit paths in unison. The attenuation level of the attenuator in the receive path is decreased, thereby decreasing the level of artificial noise receive power, increasing the natural signal level, and hence increasing the size of the reverse link coverage area. The attenuation level of the transmit path attenuator is also decreased, thereby increasing the transmit power level of the new base station and expanding its forward link coverage area. The rate at which the transmit power is increased and the artificial noise receive power is decreased must be sufficiently slow to permit handoff of calls between the new and surrounding base stations as the new base station is added to or removed from the system.
Each base station in the system is initially calibrated such that the sum of the unloaded receiver path noise and the desired pilot power is equal to some constant. The calibration constant is consistent throughout the system of base stations. As the system becomes loaded (i.e. remote units begin to communicate with the base stations), a compensation network maintains the constant relationship between the reverse link power received at the base station and the pilot power transmitted from the base station. The loading of a base station effectively moves the reverse link handoff boundary closer in toward the base station. Therefore, to imitate the same effect on the forward link, the pilot power is decreased as loading is increased. The process of balancing the forward link handoff boundary to the reverse link handoff boundary is referred to as base station breathing is detailed in U.S. Pat. No. 5,548,812 entitled "METHOD AND APPARATUS FOR BALANCING THE FORWARD LINK HANDOFF BOUNDARY TO THE REVERSE LINK HANDOFF BOUNDARY IN A CELLULAR COMMUNICATION SYSTEM" issued Aug. 20, 1996 and assigned to the assignee of the present invention. The process of balancing the forward link handoff boundary to the reverse link handoff boundary during the addition or removal of a base station from a system is referred to as base station blossoming and wilting is detailed in U.S. Pat. No. 5,475,870 entitled "APPARATUS AND METHOD FOR ADDING AND REMOVING A BASE STATION FROM A CELLULAR COMMUNICATION SYSTEM" issued Dec. 12, 1995 and assigned to the assignee of the present invention.
It is desirable to control the relative power used in each forward link signal transmitted by the base station in response to control information transmitted by each remote unit. The primary reason for providing such control is to accommodate the fact that in certain locations the forward link may be unusually disadvantaged. Unless the power being transmitted to the disadvantaged remote unit is increased, the signal quality may become unacceptable. An example of such a location is a point where the path loss to one or two neighboring base stations is nearly the same as the path loss to the base station communicating with the remote unit. In such a location, the total interference would be increased by three times over the interference seen by a remote unit at a point relatively close to its base station. In addition, the interference coming from the neighboring base stations does not fade in unison with the signal from the active base station as would be the case for interference coming from the active base station. A remote unit in such a situation may require 3 to 4 dB of additional signal power from the active base station to achieve adequate performance.
At other times, the remote unit may be located where the signal-to-interference ratio is unusually good. In such a case, the base station could transmit the corresponding forward link signal using a lower than nominal transmitter power, reducing interference to other signals being transmitted by the system.
To achieve the above objectives, a signal-to-interference measurement capability can be provided within the remote unit receiver. A signal-to-interference measurement is performed by comparing the power of the desired signal to the total interference and noise power. If the measured ratio is less than a predetermined value, the remote unit transmits a request to the base station for additional power on the forward link. If the ratio exceeds the predetermined value, the remote unit transmits a request for power reduction. One method by which the remote unit receiver can monitor signal-to-interference ratios is by monitoring the frame error rate (FER) of the resulting signal.
The base station receives the power adjustment requests from each remote unit and responds by adjusting the power allocated to the corresponding forward link signal by a predetermined amount. The adjustment would usually be small, typically on the order of 0.5 to 1.0 dB, or around 12%. The rate of change of power may be somewhat slower than that used for the reverse link, perhaps once per second. In the preferred embodiment, the dynamic range of the forward link adjustment is typically limited such as from 4 dB less than nominal to about 6 dB greater than nominal transmit power.
CDMA base stations have the ability to provide accurate control over their transmit power level. To provide accurate power control, it is necessary to compensate for variations in the gain in the various components comprising the transmit chain of the base station. Variations in the gain typically occur over temperature and aging such that a simple calibration procedure at deployment does not guarantee a precise level of output transmit power over time. Variations in the gain can be compensated by adjusting the overall gain in the transmit chain so that the actual transmit power of the base station matches a calculated desired transmit power. Each base station sector produces several signaling channels which operate at a variety of data rates and relative signal levels which combined create a raw radio frequency transmit signal. The channel element modulators, each of which corresponds to a channel, calculate the expected power of each channel signal. The base station also comprises a base station transceiver system controller (BTSC) which generates a desired output power of the sector by summing the expected powers of each channel.
A key aspect in implementing a wireless communication system is placement of antennas throughout the coverage area such that every location in the entire coverage area where a remote unit may be located is supported with sufficient signal levels. To create a distributed antenna, the transmit output of the base station is fed to a string of antenna elements each separated by delay. A distributed antenna exploits the ability of direct sequence CDMA to discriminate against multipath by creation of deliberate multipath that satisfies discrimination criteria.
A technique for improving performance of a distributed antenna system using parallel strings of discrete antennas wherein each antenna on a common string is separated from its neighbors by delay is disclosed in U.S. Pat. No. 5,280,472 entitled "CDMA MICROCELLULAR TELEPHONE SYSTEM AND DISTRIBUTED ANTENNA SYSTEM THEREFOR", which issued on Jan. 18, 1994 and assigned to the assignee of the present invention. Further development of the distributed antenna concept is disclosed in U.S. Pat. No. 5,513,176, issued on Apr. 30, 1996, entitled "DUAL DISTRIBUTED ANTENNA SYSTEM", and assigned to the assignee of the present invention. In the distributed antenna arrangement, signals transmitted from antennas of different antenna elements at a common node are provided different delay paths between the base station and the antenna. The antenna elements may comprise downconversion circuitry thus reducing the cabling path loss between the antenna elements and the base station and allowing the use of readily available SAW devices as delay elements.
Another advantage of the distributed antenna arrangement is that little site specific engineering is required for installation. Normally, antenna placement is determined only by physical constraints, together with the requirement that every location desiring service must be covered by a set of two antennas. There is no concern for the overlapping of antenna patterns. In fact, overlapping coverage is desirable in that it provides diversity operation to all terminals in the overlap area. Overlap is, however, not required.
An objective of a personal mobile communications network is to provide coverage over a large geographic region. Such broad geographic coverage is essential and must be provided on the first day of service to attract users in the present economic environment. One of the major expenses of providing coverage over a large geographic area is the acquisition of real estate and land usage rights and the installation of base stations each providing coverage for a portion of the total geographic coverage area.
Note that cable television (CATV) networks provide extensive coverage over nearly all suburban areas. Thus, if the CATV network, called the cable plant, could be used as the basis for a wireless communication network, the task of obtaining real estate and land usage rights and the expense of installing discrete base stations could be avoided. Thus, a centralized headend processor could provide the necessary signal processing functions at a single location within the geographic region and the cable distribution means could be used to carry the wireless signal to the users.
The characteristics of the CDMA system provide a myriad of advantages in a CATV based wireless system. The integration of the wireless communication network with the cable plant can be carefully orchestrated to take full benefit of the flexibility and capacity of the CDMA system. The present invention seeks to define such a system.

Method and apparatus for integration of a wireless communication system with a cable T.V. system


A method for maintaining the mode-locked state of a Fabry-Perot (FP) laser and a WDM light source using the same method for use in WDM optical communication are disclosed. The mode-locked state can be maintained irrespective of temperature change, without use of a temperature controller, by spectrum-slicing the incoherent light generated by a light source element and injecting the spectrum-sliced light to the FP laser, then the FP laser amplifies and outputs only a lasing mode coinciding with the wavelength of the injected light, wherein a lasing-mode interval of the FP laser is set to be less than a 3 dB linewidth of the injected light, so that at least one lasing mode exists inside the 3 dB linewidth of the injected light irrespective of changes in external temperature.

1. Field of the Invention
The present invention relates to Wavelength Division Multiplexing (WDM) optical communications and, more particularly, to a method for maintaining the mode-locked state of a Fabry-Perot laser irrespective of the changes in peripheral temperature, and a WDM light source incorporating the same method.
2. Description of the Related Art
A WDM passive optical network (PON) generally provides high-speed, wideband communication services using unique wavelengths assigned to each subscriber. As such, the WDM-PON can secure communication confidentiality. Further, it can accommodate a communication-capacity extension requested by each subscriber and easily extend the number of subscribers by simply adding unique wavelengths to be assigned to the new subscribers. Despite these advantages, the WDM-PON has not yet been put to practical use as it imposes a heavy economic burden on subscribers due to the need to provide a central office (CO) and each subscriber terminal with a light source of a specific lasing or oscillation wavelength as well as an additional wavelength-stabilization circuit for stabilizing the wavelength of the light source.
Accordingly, the development of an economical WDM light source is essential to realize the WDM-PON. To this end, a distributed feedback (DFB) laser array, a multi-frequency laser (MFL), a spectrum-sliced light source, and a mode-locked Fabry-Perot (FP) laser with incoherent light have been proposed. However, the DFB laser array and the MFL require a complicated manufacturing process and are costly. In addition, a wavelength stabilization and a correct wavelength selection of the light source are essential to implement the wavelength division multiplexing. Recently, the spectrum-sliced light source has been developed to provide a number of wavelength-divided channels by spectrum-slicing a broad-bandwidth optical signal through an optical filter or a waveguide grating router (WGR). For example, a light emitting diode (LED), a superluminescent diode (SLD), a Fabry-Perot (FP) laser, a fiber amplifier light source, and an ultra-short pulse light source have been proposed, and these elements do not require the spectrum-sliced light source to employ a light source of a specific lasing wavelength as well as additional equipment for achieving wavelength stabilization.
Proposed as a spectrum-sliced light source, the LED and SLD are not expensive and also have a wide optical bandwidth. However, the LED and SLD are suitable for use as a light source for upstream signals having a lower modulation rate rather than downstream signals as they have a low modulation bandwidth and a low output power. The FP laser is a low-priced, high-output element, but has disadvantages in that it cannot provide a large number of wavelength-divided channels because of its low bandwidth, and its performance degradation due to the mode partition noise is serious when modulating and transmitting a spectrum-sliced signal at a high rate. The ultra-short pulse light source is coherent and also has a very wide light-source spectrum band, but its implementation is difficult as the lasing spectrum has low stability and its pulse width is only several picoseconds.
To address the deficiencies in the above light sources, a spectrum-sliced fiber amplifier light source has been proposed as a large number of high-power, wavelength-divided channels by spectrum-slicing ASE (Amplified Spontaneous Emission) light generated by an optical fiber amplifier. However, this light source must use an additional high-priced external modulator, such as a LiNbO3 modulator, for allowing the channels to transmit data different from each other.
Another proposed light source is known as a mode-locked Fabry-Perot (FP) laser with incoherent light which produces a mode-locked signal. In order to produce the mode-locked signal, after a wide-bandwidth optical signal is generated from an incoherent light source, such as an LED or a fiber amplifier light source, through a waveguide grating router (WGR) or an optical filter, it is spectrum-sliced and then injected into an FP laser having no isolator. When a spectrum-sliced signal of a predetermined power level or more is injected into the FP laser, the FP laser generates and outputs only the light of a wavelength coinciding with the wavelength of the injected signal. Such a mode-locked FP laser with incoherent light can perform data transmission more economically by directly modulating the FP laser according to a data signal.
However, a wide-bandwidth, high-power optical signal must be injected into the FP laser in order for the FP laser to output a mode-locked signal suitable for a high-speed, long-distance transmission. Further, in the absence of controlling external temperature, the Fabry-Perot laser mode is changed to another mode when the temperature varies. This mode change causes the Fabry-Perot laser to release from the locked state, escaping from a wavelength coinciding with the wavelength of the injected spectrum-sliced signal. Thus, the mode-locked Fabry-Perot laser cannot be adapted as a WDM light source. An external temperature controller (e.g., a TEC controller) is thus indispensable to adapt such a mode-locked Fabry-Perot laser when used as a WDM light source.
FIG. 1 shows the configuration of a conventional Fabry-Perot (FP) laser having a temperature controller. As shown, the conventional FP laser includes a TEC (Thermo-Electric Cooler) controller 1, a thermistor 2, an FP laser 3, and a TEC 4. The TEC controller 1 detects the temperature of the FP laser 3 through the thermistor 2 and controls the temperature of the FP laser 3 using the TEC 4.
The conventional FP laser, however, has an increased packaging cost because the thermistor and the TEC must be coupled to the FP laser, and the need to provide an additional TEC controller further increases the overall cost. These impose a high economic burden on subscribers, so that the WDM-PON has not yet been widely accepted.

Method for maintaining mode-locked state of fabry-perot laser irrespective of temperature change and WDM light source using the same method


Two or more processes selected from heat treatment for anihilation of oxygen donors, formation of a gettering region, and formation of a dopant-volatilization-prevention film are simultaneously performed in a common apparatus in accordance with the specifications of silicon wafers to be manufactured. Therefore, productivity can be improved.

1. Field of the Invention
The present invention relates to a method of manufacturing mirror-polished silicon wafers in which processes such as formation of a gettering region, formation of a dopant-volatilization-prevention film, and heat treatment for anihilation of oxygen donors are performed successively and selectively. The present invention also relates to an apparatus for processing silicon wafers in which processes such as formation of a gettering region, formation of a dopant-volatilization-prevention film, and heat treatment for anihilation of oxygen donors are performed successively and selectively.
2. Description of the Related Art
As shown in FIG. 1, mirror-polished silicon wafers used for manufacture of silicon devices are generally manufactured through a slicing process A for slicing a silicon monocrystalline rod manufactured by a silicon monocrystal manufacturing apparatus; a chamfering process B for chamfering the peripheral edge of each of the silicon wafers thus sliced in the slicing process A in order to prevent the silicon wafer from becoming cracked or chipped; a lapping process C for lapping the thus-chamfered silicon wafer so as to form a flat surface thereon; an etching process D for eliminating mechanical damage remaining in the chamfered and lapped silicon wafer; a mirror-polishing process E for polishing at least one main face of the etched silicon wafer; and a cleaning process F for cleaning the mirror-polished silicon wafer so as to remove polishing agent and foreign matter adhered thereto.
In most cases, the mirror-polishing process E is not performed immediately after the etching process D, but, as shown in FIG. 1, an additional process G is performed between the etching process D and the mirror-polishing process E. Depending on the specifications (or application) of mirror-polished silicon wafers to be manufactured, there is carried out, as the additional process G, heat treatment for anihilation of oxygen donors, or formation of a dopant-volatilization-prevention film or a gettering region (gettering film or gettering damaged layer) on a face (hereinafter referred to as a "back surface") opposite the main face (hereinafter referred to as a "front surface") on which devices will be fabricated. In the example shown in FIG. 1, after silicon wafers undergo the etching process D, a % of the silicon wafers are transported to a process for formation of a dopant-volatilization-prevention film, b % of the silicon wafers are transported to a process for heat treatment for anihilation of oxygen donors, c % of the silicon wafers are transported to a process for formation of a gettering film, and d % of the silicon wafers are transported to a process for formation of a gettering damaged layer. The sum of a, b, c, and d is approximately 100%. Subsequently, x % of the silicon wafers that have undergone the heat treatment for donor anihilation are transported to the process for formation of a dopant-volatilization-prevention film, y % of the heat-treated silicon wafers are transported to the process for formation of a gettering film, and z % of the heat-treated silicon wafers are transported to the process for formation of a gettering damaged layer.
Since the additional processes are conducted at different apparatuses, when the silicon wafers must undergo two or more additional processes, they must be transported from one apparatus to the next apparatus. During such transportation, foreign matters may adhere to the silicon wafers. Therefore, the silicon wafers that have undergone an additional certain process must be cleaned before being subjected to the next additional process. Moreover, since the respective additional processes have different processing performances (throughputs), there is a waiting period before wafers can undergo the next process, resulting in a stock of wafers being formed between processes (hereinafter referred to as "process stock"). Therefore, when two or more kinds of additional processes are performed, the productivity decreases, resulting in an increased cost of mirror-polished silicon wafers. Also, delivery becomes delayed.
Moreover, in recent years, mirror-polished silicon wafers have been required to have various kinds of additional functions such as a gettering function. With this trend, the specifications of mirror-polished silicon wafers to be manufactured have become diversified. Since the number, kinds and sequence of required additional processes depend on a desired additional function and therefore a process stock is generated, the diversification of specifications has also caused an increase in the process stock and a decrease in productivity.
Also, when apparatuses for carrying out the respective additional processes are installed at different sites or in different buildings, silicon wafers must be transported over a long distance between the apparatuses, so that the productivity decreases further.

Method of manufacturing mirror-polished silicon wafers, and apparatus for processing silicon wafers


A steering wheel for motor vehicles is disclosed. The aim of the steering wheel is to supply information from a driver guidance system or a driver assistance system to a driver in such a way that said information is easily received and that the driver can also input information for said systems or for a telephone, without having to divert his or her attention from the traffic. To achieve this, the steering wheel is configured as a communication interface for the driver.

Motor vehicle steering wheels are known which have both an air bag and switches or push button keys with which it is possible, for example, to set a station on the radio or even to set its volume without operating the radio itself, which is usually mounted in the dashboard to the side of the driver, and without thus being distracted from the road traffic.
The increasing complexity of road traffic requires increasing driver information about his surroundings. The quantity of information which is transmitted to the driver of the vehicle is therefore increasing. On the other hand, the capacity of the driver to take in information is limited. The driver also has to concentrate on essential driving functions, which also requires increasing concentration because of the increasing amount of road traffic.
For this reason, driver assistance systems for sensing hazardous situations and driver guidance systems are being increasingly used in motor vehicles. It is known to make the driver aware of hazardous situations by means of visual systems in the dashboard or by means of audio systems. The driver guidance systems are equipped with a display which is also arranged in the dashboard. Driver assistance systems are known, for example, from German laid-open patent application 198 21 163 A1 and from European patent application 0 640 903 A1.
The disadvantage of the visual systems is that they are arranged in the dashboard on the other side of the driver, so that in particular when the driver is considering the display of a driver guidance system he cannot pay attention to the road traffic.


A method for synthesizing an organometallic compound, which is usefully utilized as a catalyst for manufacturing polyolefins by ring-opening metathesis polymerization of an olefin having strain in a molecule such as dicyclopentadiene or synthesizing epothilones by ring-dosing metathesis reaction, by an efficient and low cost synthesis method using a starting material which is easily available due to relatively simple chemical structure, and further without any possibility of coexistence of a vinylhetero compound or a vinyl compound exchanged which tends to accompany as an impurity in the system in conventional methods, characterized by reacting a starting material comprising a zero-valent transition metal complex (A) or a polyvalent transition metal complex (A′), a compound (B) or (B′) shown by the following general formula (1) or (4), respectively, and a neutral ligand (C) or (C′), in one step under non-reducing condition or reducing condition.R1Y1CR2X12  (1)R4Y2CR5X22  (4)

1. Field of the Invention
The present invention relates to a method for synthesizing an organometallic compound, and in more detail, relates to an efficient and low cost method for synthesizing an organometallic compound usefully utilized as a catalyst for polyolefin manufacturing by ring-opening metathesis polymerization of an olefin having strain in a molecule such as dicyclopentadiene or synthesis of epothilones by ring-closing metathesis reaction, by using an easily available starting material due to relatively simple chemical structure.
2. Description of the Prior Art
A reaction using a transition metal compound has been utilized, by a catalytic action of a metal complex thereof, in wide fields ranging from synthesis of low molecular weight compounds such as medicines to synthesis of polymers such as highly functional plastics.
For example, polymerization of ethylene or propylene by Ziegler-Natta catalysts consisting of titanium tetrachloride or titanium trichloride and alkyl aluminum, polymerization to obtain uniform polyolefin by Kaminsky catalysts consisting of zirconocene and methylaluminoxane, organic metathesis reactions by transition metal carbene catalysts and the like, are well known.
Recently, transition metal carbene catalysts, in particular, ruthenium carbene catalyst is attracting attention. Ruthenium carbene catalyst is a compound having a Ru═C bond in a molecule (a bond between a ruthenium atom and divalent carbon atom without charge) and, in particular, dichloro-hydrogen-phenyl-carbene-bis(tri-cyclohexyl-phosphine)ruthenium, typically shown by [(Cl2Ru═CHPh)(PCy3)2] has been developed by Grabs group of California Institute of technology and disclosed in JP-A-11-510807, JP-A-11-262667, and the like.
This compound has been found to show superior metathesis catalytic activity without deactivation even in the presence of moisture or oxygen and being not labile to a functional group in the metathesis reaction substrate, and utilized in ring-closing metathesis synthesis of various monomers useful as medicine and the like, or in manufacturing molded articles with superior mechanical strength, heat resistance, dimensional stability, and the like, by ring-opening polymerization of a norbornene type monomer, including dicyclopentadiene (hereinafter, may be abbreviated as DCPD), a typical monomer used in the metathesis polymerization, in a mold by a reactive injection molding method (hereinafter, may be abbreviated as RIM) and the like. Thus, the compound is used and attracts attention in various wide industrial fields.
However, since this catalyst is not activated in a reaction system with an alkyl metal and the like, but has an activity as a single complex, there is a problem that the reaction spontaneously starts as soon as the catalyst is added to a monomer with metathesis reactivity, and thereby dispersion of the catalyst and the like determines the reaction rate. This tendency may be a fatal problem in polymerization of a crosslinkable monomer such as dicyclopentadiene, it causes problems such as serious limitation on a process or variation of physical properties of a polymer obtained.
To overcome this problem, a method of adding triphenylphosphine or the like to a reaction system to retard polymerization is generally known. However, it also has a problem of product safety due to contamination of impurities such as phosphorus in the system.
As a catalyst to solve the above-described problems, dichloro-hydrogen-phenyl-thio-carbene-bis(tri-cyclohexyl-phosphine)ruthenium, typically shown by [(Cl2Ru═CHSPh)(PCy3)2] has been disclosed in WO 99/00396. This patent also discloses such compounds whose sulfur atom is substituted with an oxygen atom, an imino group or a phosphine-di-yl group, in the above-described chemical formula of this catalyst.
This catalyst is very superior, but a synthesis method thereof, as shown in a) and b) of Example 1 in the page 33 of said official gazette, has problems. Namely, in the case of a), a raw material itself has a complicated chemical structure such as RuCl2[P(C6H11)3]2(═CH—CrH5), and thus requires many steps in preparation, while in the case of b), a raw material, ruthenium dichloride(cis,cis-cyclopentadiene), although the chemical structure itself is simple, must be reacted with 1,8-diazabicyclo[5.4.0]undeca-7-ene and tricyclohexylphosphine, both having complicated chemical structures, in isopropanol at 80° C. for 1 hour, followed by reacting at −20° C. for 1 hour, further adding 1 mole of a solution of diethyl ether hydrochloride, stirring for 15 minutes and further adding 1-hexyne and phenyl vinyl sulfide, to synthesize the target substance, thus requiring use of many expensive raw materials and making the synthesis complicated with many reaction steps as well as disadvantageous in cost.
A method for synthesizing a hetero carbene complex such as RuCl2[P(C6H11)3]2(═CH—S—) generally includes, for example, as shown in "Chemistry. Letters", 1999, 369 or "Organometallics", 2002, 21, 2153–2164, a reaction of a conventional alkylidene complex with a vinylhetero compound such as vinyl sulfide, followed by exchanging a vinyl moiety. However, heteroalkylidene complexes synthesized by these synthesis methods have a residual vinylhetero compound from the raw material or a vinyl compound exchanged due to co-existence in the system, and it is generally known that the complex synthesized inhibits the metathesis reaction by these remaining compounds.
Therefore, in the method for synthesizing a hetero carbene complex by the vinyl exchange requires complete removal of these vinyl compounds from the system. To solve such problems, it is necessary to repeat a washing step many times after isolation. However, additional unnecessary washing step or accompanying decrease in yield is not preferable from the industrial point of view.

Process for synthesis of organometallic compounds


An erasing apparatus includes a sheet feeding unit from which a sheet is fed into the erasing apparatus, an erasing unit configured to perform an erasing processing on both surfaces of the sheet, a scanning unit configured to scan and generate image data of a bottom surface and a top surface of the sheet, a first storing unit, a second storing unit, and a controller. The controller is configured to determine, based on the image data, whether the bottom surface of the sheet is reusable and whether the top surface of the sheet is reusable. Further, the controller is configured to cause, if both the bottom and top surfaces have been subject to the erasing processing and are determined to be reusable, the sheet to be conveyed to one of the first and second storing units based on a both-sides-erased criteria.

Conventionally, there is an erasing apparatus which is capable of carrying out an erasing processing on a sheet having images formed with a color erasable material. After reading a surface of the sheet after the color erasing processing, such an erasing apparatus determines discharging destinations according to whether or not there is a residual image on the sheet.


Innovations in flexible reference picture management are described. For example, a video encoder and video decoder use a global reference picture set (“GRPS”) of reference pictures that remain in memory, and hence are available for use in video encoding/decoding, longer than conventional reference pictures. In particular, reference pictures of the GRPS remain available across random access boundaries. Or, as another example, a video encoder and video decoder clip a reference picture so that useful regions of the reference picture are retained in memory, while unhelpful or redundant regions of the reference picture are discarded. Reference picture clipping can reduce the amount of memory needed to store reference pictures or improve the utilization of available memory by providing better options for motion compensation. Or, as still another example, a video encoder and video decoder filter a reference picture to remove random noise (e.g., capture noise due to camera imperfections during capture).

Engineers use compression (also called source coding or source encoding) to reduce the bit rate of digital video. Compression decreases the cost of storing and transmitting video information by converting the information into a lower bit rate form. Decompression (also called decoding) reconstructs a version of the original information from the compressed form. A "codec" is an encoder/decoder system.
Over the last 25 years, various video codec standards have been adopted, including the ITU-T H.261, H.262 (MPEG-2 or ISO/IEC 13818-2), H.263, H.264 (MPEG-4 AVC or ISO/IEC 14496-10) standards, the MPEG-1 (ISO/IEC 11172-2) and MPEG-4 Visual (ISO/IEC 14496-2) standards, and the SMPTE 421M (VC-1) standard. More recently, the H.265/HEVC standard (ITU-T H.265 or ISO/IEC 23008-2) has been approved. A video codec standard typically defines options for the syntax of an encoded video bitstream, detailing parameters in the bitstream when particular features are used in encoding and decoding, in many cases, a video codec standard also provides details about the decoding operations a video decoder should perform to achieve conforming results in decoding. Aside from codec standards, various proprietary codec formats define other options for the syntax of an encoded video bitstream and corresponding decoding operations.
In a typical video sequence, most regions of a given picture are the same, or change only slightly, compared to pictures before the given picture and after the given picture. Most video codec standards and formats use inter-picture prediction to exploit such picture-to-picture redundancy in a video sequence. For example, if a block of sample values in the given picture is predicted using inter-picture prediction, a video encoder estimates the motion of the block relative to one or more other, previously encoded/decoded pictures, which are available for reference when encoding/decoding the given picture. The other, previously encoded/decoded pictures are called reference pictures. When the video encoder finds a matching block within a reference picture for the block of the given picture, the video encoder represents the matching block, e.g., using an identifier of the reference picture and the location of the matching block (relative to the location of the block of the given picture). The video encoder can determine differences between the block of the given picture and the matching block, then encode those differences.
According to some video codec standards and formats, a video encoder and video decoder apply simple rules to determine which reference pictures to retain in a buffer for inter-picture prediction, and to determine which reference pictures to remove from the buffer. According to other video codec standards and formats, a video encoder has more control over which reference pictures to retain or remove from the buffer, and the video encoder signals information to a video decoder so that the video decoder can update reference pictures accordingly. Prior video codec standards and formats are not sufficiently flexible in terms of options for reference picture management, which can hurt coding efficiency and result in inefficient use of resources during video encoding/decoding.

Flexible reference picture management for video encoding and decoding


Disclosed is a display device using a demultiplexer. The demultiplexer sequentially samples the data current that is time-divided and applied by a data driver, and holds it to the data lines. Since the demultiplexer is to sample the data currents corresponding to N data lines during one horizontal period when performing 1:N demultiplexing, the data current corresponding to one data line is sampled during the 1/N horizontal period. In the present invention, a signal line coupled between the demultiplexer and the data driver is precharged with the current before coupling a precharge circuit to a sample/hold circuit and sampling the data current. The precharge current is M times the data current where M is a real number greater than 1.

(a) Field of the Invention
The present invention relates to a display device using a demultiplexer. More specifically, the present invention relates to a display device for performing demultiplexing via a sample/hold circuit.
(b) Description of the Related Art
A display device generally requires a scan driver for driving scan lines and a data driver for driving data lines. The data driver has as many output terminals as it has data lines to convert digital data signals into analog signals and apply them to all of the data lines. In general, the data driver is configured with a plurality of integrated circuits (ICs). The plurality of ICs are used to drive all of the data lines given that a single IC is limited in the number of output terminals it contains. Demultiplexers may be adopted, however, to reduce the number of data driver ICs.
For example, a 1:2 demultiplexer receives data signals that are time-divided and applied by the data driver through a signal line. The demultiplexer divides the data signals into two data groups and outputs them to two data lines. Therefore, usage of a 1:2 demultiplexer reduces the number of data driver ICs by half. The recent trend with liquid crystal displays (LCDs) and organic electroluminescent displays is to mount the ICs for the data driver on the panel. In this instance, there is a greater need to reduce the number of data driver ICs.
Under current technology, when the IC for the demultiplexer, the data driver, and the scan driver is manufactured to be directly mounted on the panel, power supply points, power supply lines, and power wiring are formed as shown in FIG. 1 to supply power to the pixels.
Referring to FIG. 1, a left scan driver 20 is provided on a display area 10 for applying select signals to select scan lines SE1 to SEm, and a right scan driver 30 is provided on the display area for applying signals for controlling light emission to emit scan lines EM1 to EMm. A demultiplexer unit 40 and a data driver 50 are also provided on the display area for applying data signals to data lines D1 to Dm. In this instance, vertical lines 60 are formed for supplying power supply voltages to the respective pixels, and a power line 70 coupled to each vertical line 60 on the top of the substrate is formed in the horizontal direction. Power line 70 and an external power supply line 80 surrounding scan drivers 20, 30 are coupled through a power supply point 90.
In this instance, since the current flows through power line 70 and vertical line 60 when a power supply voltage is used in the pixels, a voltage drop (i.e., an IR drop) is generated in power line 70 and vertical line 60 because of parasitic resistance in power line 70 and vertical line 60. The further along power line 70 and vertical line 60 from power supply point 90, the greater the voltage drop that is generated, the generated voltage drop being the greatest near the center of power line 70 and near the bottom of vertical line 60.
In general, since the pixels have characteristic deviations of driving transistors, it is generally required to obtain a margin of the saturation area in the characteristic curve of the driving transistors. However, when a great voltage drop is generated, power consumption is increased due to a general need to enlarge the power supply voltage to obtain a sufficient margin of the saturation area. Also, when sample/hold circuits are used for 1:N demultiplexing in the demultiplexer, it is generally required to sample the data current which corresponds to a data line during a 1/N time of a particular horizontal period, shortening the sampling time, and hindering an appropriate sampling of the data current.


A package assembly for electronic components that allows for low-cost multiple cavities as well as a multiple compartment structure that allows more components in a smaller package size. In one embodiment the present invention is a multi-cavity package having at least one substrate forming at least one cavity with the substrate coupled to a shelf within the sidewalls of the package.

Miniaturization of electronic components has been an on-going trend in the electronics industry. The consuming public demands more processing and capabilities in smaller and smaller packages. While many electronic functions can be transistorized, certain electronic functions, such as frequency control devices, present packaging challenges. This challenge is further complicated when certain components require isolation from other components in the same package.
For example, crystal resonators are used for providing highly precise frequency references for many applications. Piezoelectric quartz crystal resonators are commonly implemented in such oscillators to provide highly accurate timing signals for communications, navigation and radar applications. The piezoelectric devices, such as piezoelectric quartz filters, piezoelectric quartz resonators and the like, typically include a piece of piezoelectric material mounted to a substrate. The quartz element can have thin metallic electrodes attached to it through which electrical signals are coupled into and out of the piezoelectric quartz material. Common problems with piezoelectric devices are adequately isolating the piezoelectric device from mechanical shock and dealing with thermal expansion coefficient mismatches between the piezoelectric material and the substrate material.
There have been attempts to alleviate some of the problems described herein that have had only limited success. A dual cavity package has been implemented in the AT&T TRU-200 package. In addition, the 'H-package' is described in U.S. Pat. Nos. 5,500,628 and 5,405,476. The H-package uses thick film technology and has a hermetic bottom cavity on one side that is disposed to have the additional non-hermetic cavity. There are several references that illustrate some form of package shelves, namely the chip carrier of U.S. Pat. No. 4,903,120 and the high density package of U.S. Pat. No. 4,943,844. Stackable packages are described in U.S. Pat. No 6,518,659. Multiple chamber or cavity packages of some form are depicted in U.S. Pat. Nos. 4,985,687; 4,627,533; and 5,729,181. Other references include U.S. Pat. Nos. 5,771,556 and 6,133,674.
The state of the art suffers from the problem of how to incorporate the individual components of a larger package into a smaller package. One possible solution is a package design that suspends a substrate to a package by mounting on shelves. Such a design can employ the thick film as well as thin film or flex circuit technology and allow high performance components such as inductors, capacitors, and varactors to be incorporated.


A television system is provided which includes a display screen connected to or integrally formed with a broadcast data receiver (BDR). The BDR receives data from a broadcaster at a remote location and decodes the data to form video, audio and/or auxiliary data. At least part of the decoded data is used to generate first and second windows (4, 6, 8, 20, 22) on the display screen and one or more of the windows contain user selectable options. Upon user selection of a particular option (24) from the first window, at least a part of the first or second windows (4, 6, 8, 20, 22) are reconfigured, such that the at least part of the first window covers or disables a remaining part of the first window and/or a part or whole of the at least second window.

This invention relates to a television system.
The television system referred to in the following description, which is used as an example to illustrate an application of the present invention, includes a display screen and a broadcast data receiver (BDR) connected thereto for receiving digital data from a broadcaster at a remote location via cable, satellite and/or terrestrial transmission means. The BDR decodes the data to provide visual, audio and/or auxiliary data. At least part of the decoded data is used to generate an electronic program guide (EPG) for providing information relating to various television programs and channels. EPGs are well known in the field of digital television, and provide an alternative means to conventional television listings provided in a paper format for obtaining. information relating to present and future television programs viewing.
There are many different formats in which EPGs can be displayed on a television display screen, and such display formats are often user selectable. However, a typical EPG can include a plurality of windows which are substantially simultaneously viewable as a single display. For example, one window can include a PIP or preview window for the display of a program currently being shown on a particular channel, one window can include program listings for a particular time span for one or more channels, a further window can include means for setting reminders for programs, recording programs and/or the like. At least one of the windows has user selectable options provided therein which a user can select using control means, such as a remote control handset. User selection of one or more of the options may result in the BDR generating a message on the display screen which requires a user.
The pop-up window is a new window which is generated and superimposed over the existing windows on the display screen to form at least a second display layer over the original layer(s). The user is unable to make any further selections from the windows in the original display layer until the user responds to the message in the pop up window of the at least second display layer. Thus the pop-up window acts to guarantee a user response to a query or message generated by the BDR.
It is an aim of the present invention to provide an alternative means of guaranteeing a user response on a display screen of a television system.


The present invention relates to a method of assay and a kit for carrying out the assay for determining the physical condition of biological cells in vitro. The assay method distinguishes whether cells are alive and proliferating or are dying and, if dying, whether the cells are in an apoptotic or necrotic condition.

1. Field of the Invention
The present invention relates to an assay, and kit for carrying out the assay, for determining the physical condition of biological cells in vitro. Particularly, it distinguishes whether cells are alive and proliferating or are dying and, if dying, whether they are in an apoptotic or necrotic condition.
2. Description of the Related Art
Many different cell types are used for the screening of chemical compounds as prospective drugs. Prospective drugs are added to cell cultures in micotitre plates at various concentrations in duplicate or triplicate, so that the average microtitre plate is used to test for many different drugs. After the cells have been incubated for a period of time (depending on the cell type, but usually several days), the effect of the prospective drug on the cells in each well is determined.
The pathway leading to cell death, is important. Cell death may follow two distinct modes: apoptosis and necrosis. Apoptosis is the normal mode and is an active intrinsically controlled process in which the cell commits suicide in response to a wide range of physiological and toxicological signals. It occurs during embryonic development as well as in the adult, controlling immune systems and tissue turnover to regulate a stable balance of tissue mass. Apoptosis also occurs in response to an altered environment, including depletion of growth factors, serum or oxygen and upon exposure to harmful stimuli such as radiation and hyperthermia. Apoptotic cells are removed in vivo by phagocytosis from neighbouring cells and macrophages without invoking an inflammatory response. Necrosis, on the other hand, is a passive pathological event that occurs under severe conditions causing sudden cellular damage and significant loss in tissue architecture. Necrotic cells release their cytoplasmic contents into the extracellular fluid, generating an inflammatory reaction. In in vitro conditions, there is no rapid removal mechanism of apoptotic cells, and so the cells accumulate and ultimately undergo necrotic cell death. Necrotic cell death in these circumstances is termed "secondary necrosis". Ordinary necrosis is termed "primary necrosis".
A determination of the effect of a treatment on the pathway leading to cell death is vital if screening for therapeutic agents is to be successful.
As mentioned above, it is now known that normal cells die by apoptosis, a predetermined pathway which is encoded genetically. Cancer cells have been shown to possess one or more defects which prevent normal cell death from occurring. These defects allow cancer cells to proliferate in an uncontrolled manner.
An assay for determining whether a treatment caused a cancer cell line to undergo cell death by apoptosis is valuable, since it allows one to determine whether or not a treatment can cause the cells to switch back to the normal apoptotic pathway mechanisms of cell death. Such a treatment would of course be preferable to whole scale cytotoxic drugs which may kill normal as well as cancer cells.
In other conditions, such as Alzheimer's Disease, the basis of the condition is cell death. A screening method which can determine whether or not a treatment causes cellular proliferation helps to identify drugs which could correct the cell death exhibited by the condition.
Very potent apoptotic agents may be overlooked because they appear to cause necrosis rather than apoptosis, when in fact they cause apoptosis quickly and the necrosis detected is secondary necrosis which follows apoptosis. It is therefore valuable to detect secondary necrosis.
One of the most significant and early events in necrosis is swelling of mitochondria (hydropic swelling), which is reversible in the early stages providing the causative agent is removed or reversed. However, beyond a certain point the cell will die, and unlike apoptosis, the cells swell, the plasma membrane becomes leaky, resulting in uncontrolled release of the cells constituents such as proteolytic enzymes and inflammatory mediators. In vivo, these substances trigger an inflammatory response in the tissue, resulting in permanent uncontrolled damage, which in certain situations may prove life-threatening.
The feature of a leaky plasma membrane is the basis of a test using propidium iodide (PI) with flow cytometry and allows the viability of the cells to be tested: necrotic cells will stain but apoptotic cells (except in the later stages of apoptosis), or proliferating cells will not. DNA fragmentation in necrosis is not as extensive as in apoptosis and is heterogeneous in size, resulting in a smear on gel electrophorsis. This difference in DNA fragmentation is the basis for the "TUNEL" (Terminal deoxytransferase deoxy Uridine triphosphate-mediated Nick End Labelling) technique which probably represents the best method for determining apoptosis at present and allows differentiation between necrosis and apoptosis. The problem with this method (apart from the very high cost of the equipment) is that it cannot be automated and a set of 20 samples takes up to three hours to prepare, measure and analyse. It is therefore totally unsuitable for screening purposes.
Primary necrosis differs from secondary necrosis in that primary necrosis results in the features detailed above, while necrosis secondary to apoptosis results in increased uptake of the TUNEL label initially, followed by increased uptake of the PI stain due to a leaky plasma membrane in the latter stages of the process.
All of the available methods are limited by the inherent problems of the flow cytometry technology and therefore are not suitable for large scale or high throughput screening.
It is a problem that there are currently no methods available for high throughput assay of the condition of cells, particularly for use in small assay volumes, as in wells of microtitre plates.

Assay and kit for determining the condition of cells