An at least partially implantable system for rehabilitation of a hearing disorder with an arrangement for processing and/or generation of signals is provided including an implantable processor arrangement with control logic which operates according to an operating program and an implantable storage arrangement for storage of the operating program and of operating parameters. A wireless telemetry unit is provided for data transmission between the implantable part of the system and an external unit. The system also includes a power supply arrangement which supplies individual components of the system with current and a rewritable implantable storage arrangement assigned to the processor arrangement for holding and reproducing the operating program and the operating parameters. At least a part of the operating program and/or of the operating parameters can be modified and/or replaced by data transmitted from the external unit via the telemetry unit.

1. Technical Field
This invention relates to an at least partially implantable system for rehabilitation of a hearing disorder with an arrangement for processing and/or generating signals, which includes an implantable processor arrangement with control logic which operates according to an operating program and an implantable memory arrangement for storage of the operating program and of operating parameters. Also, the invention relates to systems including a wireless telemetry means for data transmission between the implantable part of the system and an external unit, and a power supply arrangement which supplies individual components of the system with current.
2. Description of Related Art
Rehabilitation of sensory hearing disorders with partially implantable electronic systems in recent years has acquired major importance. The expression "hearing disorder" is defined here as inner ear damage, middle ear damage, combined inner ear and middle ear damage, cochlear deafness which necessitates use of a cochlea implant, likewise retrocochlear hearing disorders which necessitate use of an auditory brain stem implant, i.e. briefly, everything which prevents or adversely affects sound reception and/or relay to the brain stem. "Hearing disorders" here furthermore include temporary or permanent noise in the ears (tinnitus). In particular, the use of partially implantable electronic systems applies to the group of patients in which hearing has completely failed due to accident, illness or other effects or is congenitally absent. If, in these cases, only the inner ear (cochlea), and not the neuronal auditory path which leads to the center, is affected, the remaining auditory nerve can be stimulated with electrical stimulation signals and thus a hearing impression can be produced which can lead to clear understanding of speech. In these so-called cochlea implants, an array of stimulation electrodes, which is triggered by an electronic system, is inserted into the cochlea. This hermetically tight and biocompatibly encapsulated electronic module is surgically embedded in the bony area behind the ear (mastoid). However, the electronic system contains essentially only decoder and driver circuits for the stimulating electrodes, sound reception and conversion of this acoustic signal into electrical signals, while their further processing takes place basically externally in a so-called speech processor which is carried outside on the body. The speech processor converts the preprocessing signals coded accordingly into a high frequency carrier signal which via inductive coupling is transmitted through the closed skin (transcutaneously) to the implant. The sound-receiving microphone is located without exception outside the body, and in most applications, in a housing of a behind-the-ear hearing aid worn on the external ear, and is connected to the speech processor by a cable. These cochlea implant systems, their components and principles of transcutaneous signal transmission are described by way of example in U.S. Pat. No. 5,070,535, U.S. Pat. No. 4,441,210, published European patent application No. 0 200 321 and U.S. Pat. No. 5,626,629. Methods of speech processing and coding in cochlea implants are disclosed for example, in published European patent No. 0 823 188, published European patent No. 0 190 836, U.S. Pat. No. 5,597,380, U.S. Pat. No. 5,271,397, U.S. Pat. No. 5,095,904, U.S. Pat. No. 5,601,617 and U.S. Pat. No. 5,603,726.
In addition to the rehabilitation of deaf patients, or those who have lost their hearing, using cochlea implants, for some time there have been approaches to offer better rehabilitation using partially or fully implantable hearing aids than with conventional hearing aids to patients with sensorineural hearing disorder which cannot be surgically corrected. The principle consists, in most embodiments, in directly stimulating an ossicle of the middle ear or the inner ear via mechanical or hydromechanical stimulation and not via the amplified acoustic signal of a conventional hearing aid in which the amplified acoustic signal is sent to the external auditory canal. The actuator stimulus of these electromechanical systems is accomplished with different physical transducer principles such as, for example, by electromagnetic and piezoelectric systems. The advantage of these processes lies mainly in the sound quality which is improved compared to conventional hearing aids and, for fully implanted systems, in the fact that the hearing prosthesis is not visible. These partially and fully implantable electromechanical hearing aids are described, for example, by Yanigahara et al. in Arch Otolaryngol Head Neck, Surg-Vol 113, August 1987, pp. 869-872; Suzuki et al. in Advances in Audiology, Vol. 4, Karger Basel, 1988; Leysieffer et al. in HNO, Vol. 46, 1998, pp. 853-863; Zenner et al. in HNO, Vol. 46, 1998, pp. 844-852; and in numerous patent documents, especially in commonly assigned U.S. patent application Ser. No. 09/097,710, in U.S. Pat. Nos. 4,850,962; 5,277,694; 5,411,467; 5,814,095; 3,764,748; 4,352,960; 5,015,224; 5,015,225; 3,557,775; 3,712,962; 4,729,366; 4,998,333; and 5,859,916, published European Patent No. 0 263 254, published PCT Application Nos. 98/36711; 98/06237; 98/03035; 99/08481; 99/08475; 99/07436; and 97/18689.
Many patients with inner ear damage also suffer from temporary or permanent noise in the ears (tinnitus) which cannot be surgically corrected and against which there are no drug forms of treatment to date. Therefore, so-called tinnitus maskers are available; they are small, battery-driven devices which are worn like a hearing aid behind or in the ear. By means of artificial sounds which are emitted via, for example, a hearing aid speaker into the auditory canal, the maskers mask the tinnitus by psychoacoustic means and thus reduce the disturbing noise in the ears, as much as possible, below the threshold of perception. The artificial sounds are often narrowband noise (for example, third-octave noise) which can be adjusted in its spectral location and loudness level via a programming device to enable adaptation to the individual tinnitus situation as optimally as possible. In addition, recently, the so-called retraining method has been introduced in which by combination of a mental training program and presenting broadband sound (noise) near the resting hearing threshold, the perceptibility of the tinnitus is likewise to be largely suppressed Journal "Hoerakustik" 2/97, pages 26 and 27). The devices used in this training program are also called "noisers".
In the two aforementioned methods for hardware treatment of tinnitus, hearing aid-like technical devices must be worn visibly outside on the body in the area of the ear. These devices stigmatize the wearer and therefore are not willingly worn.
U.S. Pat. No. 5,795,287 discloses an implantable tinnitus masker with direct drive of the middle ear, for example, via an electromechanical converter, coupled to the ossicular chain. This directly coupled transducer can preferably be a so-called "Floating Mass Transducer" (FMT). This FMT corresponds to the transducer for implantable hearing aids which is described in U.S. Pat. No. 5,624,376.
Implantable systems for the treatment of tinnitus by masking and/or noiser functions have been proposed, in which corresponding electronic modules are added to the signal-processing electronic path of a partially or fully implantable hearing system such that the signals necessary for tinnitus masking or noiser functions can be fed into the signal processing path of the hearing aid function and the pertinent signal parameters can be adapted by further electronic measures individually to the pathological requirements. This adaptability can be accomplished by the necessary setting data of the signal generation and feed electronics being filed or programmed in the same physical and logic data storage area of the implant system. Also, the feed of the masker or noiser signal into the audio path of the hearing implant can be controlled via the corresponding electronic means.
In all the above-described rehabilitation devices, it now seems to be a good idea to design the systems such that they can be completely implanted. These hearing systems, depending on the desired function, consist of three or four function units: a sensor (microphone) which converts the incident airborne sound into an electrical signal; an electronic signal processing, amplification and implant control unit; an electromechanical or implantable electroacoustic transducer which converts the amplified and preprocessed sensor signals into mechanical or acoustic vibrations and sends the signals, via suitable coupling mechanisms, to the damaged middle and/or inner ear, or a cochlear stimulation electrode for cochlea implants; and an electric power supply system which supplies the aforementioned modules. Furthermore, there can be an external unit which makes available electrical recharging energy to the implant when the implant-side power supply unit contains a rechargeable (secondary) battery. Especially advantageous devices and processes for charging of rechargeable implant batteries are described in commonly assigned U.S. patent application Ser. No. 09/311,566 and in published European patent No. 0 499 939. Feasibly, a telemetry unit can also be provided with which patient-specific, audiological data can be transmitted bidirectionally or programmed in the implant and thus permanently stored, as was described by Leysieffer et al. in HNO Vol. 46, 1998, pp. 853-863.
Basically, in all the above-described at least partially implantable systems, the (audio) signal processing or signal generation and the modules of the implant control are built, for example, like a controlled battery recharging system or a telemetry system for bidirectional transmission of, for example, variable, patient-specific parameters on the implant-side by permanently fixed hardware units. This design feature also applies in cases in which digital signal processors or microcontrollers or microprocessors are used for signal processing or generation or for implant management, regardless of whether they are built as so-called "hardwired logic", i.e. in "hardwired" logic architecture, or whether their operating programs are filed in the read-only memories (ROM) of the corresponding processors. These programs, which are provided and necessary for basic operation of the implant and for proper operation, are called hereinafter the operating program or operating software. This operating software is placed in the implant systems described in the prior art during production, for example, by mask programming of the processor storage areas and can no longer be changed after implantation.
In contrast, patient-specific data such as, for example, audiologic adaptation data or also variable implant system parameters (for example, as a variable in one of the aforementioned software programs for controlling battery recharging) are referred to as operating parameters. These operating parameters can be transmitted transcutaneously to the implant according to the aforementioned prior art in fully implantable implant systems after implantation, i.e. wirelessly through the closed skin and, thus, can be changed.
If, on the other hand, the operating software is to be changed because, for example, due to more recent scientific findings, improved algorithms for speech signal processing are available in, for example, fully implanted cochlea implants or electromechanical hearing systems for rehabilitation of an inner ear disorder, the entire implant or implant module which contains the corresponding signal processing unit must be replaced by a new unit containing the altered operating software by invasive surgery on the patient. This surgery entails renewed medical risks for the patient, and is especially serious in the application of cochlea implants in children as patients. In addition, the surgery is very costly. In addition, this system change can only be done completely, especially in cochlea implants, i.e. with removal of the stimulation electrode, since a technically very complex, multipin and detachable plug connection to the signal processing implant module is not used given the currently conventional large number of stimulus channels.

Implantable system for rehabilitation of a hearing disorder

IMPLEX Aktiengesellschaft Hearing Technology


System and method for laser welding an inner surface of a small diameter tubular member. The system includes a laser for generating laser light and a mirror optically coupled to the laser for reflecting the light onto the inner surface of the tubular member to laser weld the inner surface of the tubular member. A rotator assembly is connected to the mirror for rotating the mirror in order to weld around the inner surface of the tubular member. The mirror and rotator assembly are each sized to be disposed in the tubular member at a location adjacent the portion of the tubular member to be welded. The rotator assembly has a spiral groove formed in the exterior thereof for receiving a cord wrapped around the exterior of the rotator assembly. An end of the cord is connected to a motor located externally to the tubular member, so that the cord is pulled as the motor is operated. As the cord is pulled, the rotator assembly rotates for rotating the mirror. A retainer is also provided for retaining the cord in the groove as the rotator assembly rotates. Therefore, the rotator assembly and the mirror associated therewith are rotated by a motor located externally to the tubular member. Thus, the system and method of the invention are capable of welding small diameter (e.g., diameters equal to or less than 0.313 inch) tubular members because the motor is located externally to the tubular member rather than being disposed in the tubular member.

This invention generally relates to welding apparatus and methods and more particularly relates to a system and method for laser welding an inner surface of a small diameter tubular member, which tubular member may be a repair sleeve disposed in a nuclear heat exchanger heat transfer tube.
Although laser welding apparatus and methods are known, it has been observed that these apparatus and methods have a number of operational problems associated with them that make such apparatus and methods less than completely satisfactory for welding an inner surface of a small diameter tubular member. However, before these problems can be appreciated, some background is desirable as to the structure and operation of a typical nuclear heat exchanger.
In a typical nuclear heat exchanger or steam generator, a heated and radioactive primary fluid flows through a plurality of U-shaped tubes, each of the tubes having a fluid inlet and a fluid outlet end. The inlet and outlet ends of the tubes are received through holes in a tubesheet disposed in the heat exchanger for supporting the tubes. The heat exchanger defines an inlet plenum chamber below the tubesheet, which inlet plenum chamber is in communication with the inlet ends of the tubes. The heat exchanger also defines an outlet plenum chamber below the tubesheet and isolated from the inlet plenum chamber, the outlet plenum chamber being in communication with the outlet ends of the tubes. During operation of the heat exchanger, a heated and radioactive primary fluid flows into the inlet plenum chamber and enters the inlet ends of the tubes to flow through the tubes. After flowing through the tubes, the primary fluid then flows through the outlet ends of the tubes and into the outlet plenum chamber. The primary fluid next flows out the outlet plenum chamber to exit the heat exchanger. A nonradioactive secondary fluid having a temperature less than the primary fluid simultaneously surrounds the exterior surfaces of the tubes above the tubesheet as the primary fluid flows through the tubes. Thus, as the heated primary fluid flows through the tubes, it gives-up its heat to the secondary fluid surrounding the exterior surfaces of the tubes to produce steam that is used to generate electricity in a manner well known in the art.
Because the primary fluid is radioactive, the heat exchanger is designed such that the radioactive primary fluid flowing through the tubes does not commingle with and radioactively contaminate the nonradioactive secondary fluid surrounding the exterior surfaces of the tubes. Therefore, the tubes are designed to be leak-tight so that the radioactive primary fluid remains separated from the nonradioactive secondary fluid to avoid commingling the primary fluid with the secondary fluid.
Occasionally, however, the heat exchanger tubes may degrade and thus may not remain leak-tight due, for example, to tube wall intergranular cracking caused by stress and corrosion occurring during operation of the heat exchanger. Therefore, the tubes are inspected to detect such stress corrosion cracking or degradation. If stress corrosion cracking is detected at a particular location in the wall of the tube, then the tube is "sleeved" at that location. When sleeving is performed, a tubular metal sleeve is inserted into the tube, so as to cover the degraded portion of the tube, and affixed thereto typically by expanding the sleeve into intimate engagement with the tube. In this manner, the sleeved tube remains in service although degraded.
However, the elastic properties of the metal sleeve may cause the sleeve to experience partial "spring back" after expansion. This phenomenon of "spring back" may in turn cause a relatively small gap to exist at the sleeve-to-tube interface. Such a gap is undesirable because the gap defines a flow path between the sleeve and the tube, which flow path may allow the radioactive primary fluid to flow through any crack in the tube and thereafter undesirably commingle with the nonradioactive secondary fluid. Therefore, it is desirable to fuse the sleeve to the tube by forming, for example, two spaced-apart weldments circumscribing the inner surface of the sleeve in order to seal the gap and the flow path defined thereby. In this regard, laser welding has been used to fuse such a sleeve to the tube.
Laser welding devices are known. A system and method for laser welding a tube is disclosed in U.S. Pat. No. 5,182,429 titled "System And Method For Laser Welding The Inner Surface Of A Tube" issued Jan. 26, 1993 in the name of William E. Pirl, et al. and assigned to the assignee of the present invention. This patent discloses a system and method for laser welding a sleeve to the inner surface of a heat exchanger tube in order to repair the tube. The Pirl, et al. system comprises an elongated tubular housing having a rotatable distal portion connected to a non-rotatable proximal portion, a fiber-optic cable for conducting remotely generated laser light into the tubular housing, a beam deflection mechanism supported within the distal portion of the housing and a reflector for radially directing and focusing laser light received from the fiber-optic cable toward the inner wall of the sleeve to weld the sleeve. In order to weld around the inner wall of the sleeve, the Pirl, et al. device provides an electric motor within the proximal portion of the tubular housing to rotate the distal portion of the housing and the reflector supported therein.
However, applicant has observed that such a prior art laser welding device and its associated motor are unsuitable for welding a sleeve having a relatively small inner diameter (e.g., an inner diameter equal to or less than approximately 0.313 inch). This is so because the size of commercially available motors is necessarily larger than the relatively small inner diameter of the sleeve. Therefore, a problem in the art is to rotate the distal portion of the tubular housing and the reflector supported therein without locating the motor within the proximal portion of the housing, so that relatively small diameter sleeves can be welded.
Therefore, what is needed are a system and method for laser welding an inner surface of a small diameter tubular member, which tubular member may be a repair sleeve disposed in a nuclear heat exchanger heat transfer tube.


A method and system for single-session sign-on management are provided. Multiple servers may be provided. The servers may have both log-in plug-in modules and session management plug-in modules. Providing the plug-ins on individual servers reduces network traffic generally required in order to grand a validate user credentials. Thus, a second server may validate a user credential created by a first server and may additionally create a user credential if it cannot validate the credential created by the first server.

1. Field of the Invention
The present invention relates to session management, and more particularly to single sign-on session management across multiple servers without requiring a central session management server.
2. Description of the Related Art
As known in the field of electronic information access, it is common for protected resources on a server to require some form of authentication or certification before the protected resources are provided to a client user. As an example, the client user at a computer with a browser application, such as INTERNET EXPLORER or NETSCAPE, connects to the server over the Internet and attempts to access, down-load or view a protected resource. Before allowing access to the protected resource, the server must verify that the client user is allowed access to the protected resource. This may take the form of validating the user's credentials against a list of authorized users through a log-in process. Once the user is authenticated through the log-in process, the user is granted credentials and a session between the client and the server is established. It is common for a client user to want access to protected resources on multiple servers. Unless there is some form of sharing or communication between the servers, the client user must log-in to each of the servers. This is not particularly advantageous, and to overcome these disadvantages, single sign-on session management servers have been developed and fielded. Examples of these types of session management systems are the system provided by ENTRUST, of Plano Tex., called GETACCESS, and the system provided by NETEGRITY of Waltham Mass., called NETEGRITY SITEMINDER. It is common with these types of single sign-on session management systems to use a central session management server, connected to the protected resource servers. In some configurations, central session management is hosted on a single server. In other configurations, a number of servers host the central session management, with the individual servers inter-connected and acting as a single logical server. A single logical server requires an exchange of information between the individual servers to maintain a consistent data set.
The central session management server validates the session credentials of client users. This system architecture allows a single sign-on and shared use of the session credentials. However, a central session management server is a potential single point for managing and controlling all sessions in the system and is therefore vulnerable as a single point of failure. A central session management server can also limit network performance for session updates. As a network scales, there are more applications in the single sign-on environment and more traffic to and from the session manager. Therefore, in addition to being a single point of failure, this type of architecture with a central session management server can impose additional network traffic loads. The additional network traffic loads can have a significant effect when session management is distributed over a wide area network, where bandwidth tends to be more restricted than over a local area network.
One of the reasons that systems use a central session management server is to provide a central location to check for session invalidity. This requires a check for credential invalidity each time a client accesses a server application. However, session invalidity is a very rare event. Therefore, checking for credential validity creates a significant volume of overhead to detect a rare event.
What is needed is a system and method that provides single session sign-on without requiring a central session management server, without providing a single point of failure, or without the associated network traffic load.
The preceding description is not to be construed as an admission that any of the description is prior art relative to the present invention.

This patent is subject to a terminal disclaimer.

System and method for single sign-on session management without central server


The present invention relates to a method for culturing mammalian cells in a culture medium which is transferrin free and which contains no lipophilic or synthetic nitrogen-containing chelators. Also provided is the use of the medium and a process for providing a mammalian product by culturing cells capable of producing the product in the medium.

Cell culture media must provide the nutrients necessary to maintain and grow cells in a controlled, artificial and in vitro environment. The particular characteristics of the cell culture media depend to a large extent on the type of cell being cultured and, to a lesser extent on the method of culture.
Mammalian cells have an absolute requirement for iron, which, in vitro, is supplied in the cell culture medium. Bertheussen (Cytotechnology 11:219-231, 1993) has commented that iron cannot be effectively supplied to mammalian cells by adding simple iron salts to the cell culture medium, primarily due to the availability of iron to the cells being reduced by rapid oxidation and precipitation of iron.
Iron in free form, furthermore, has a high oxidative potential, which may result in oxidation of components of a cell culture medium. It has therefore been proven to be of benefit to complex the iron so as to reduce or eliminate this oxidative potential.
In vivo, iron is presented to the mammalian cells by the iron binding protein transferrin. Transferrin works by binding iron and interacting with a transferrin receptor on the cell surface. The transferrin-iron complex is then taken into the cell by endocytosis. Once in the cell, the transferrin-iron complex is broken and the released iron is then complexed to an iron transporting protein (ferritin). The transferrin is recycled. Thorstensen and Romslo, Biochem. J., 271:1-10 (1990) offer an excellent review of this in vivo iron transfer mechanism. The ability of transferrin to mediate transport of iron to cells has been exploited in cell culture by the simple addition of transferrin and an iron salt to the cell culture medium.
However, the transferrin typically used in cell culture media is of animal origin and in recent years there has been increasing regulatory pressure to remove proteins of animal origin from cell culture processes. Clearly the use of proteins of animal origin carries with it the risk of introducing contaminants and adventitious pathogens such as Creutzfeld-Jakob disease (CJD) or Spongiform Encephalopathy (Mad Cow Disease). Alternative iron transporters to transferrin have therefore been sought and applied with varying degrees of success. The type and concentration of any alternative iron transporter has often been found to be dependent on the type of mammalian cell being cultured.
Kovar and Franek (Biotechnology Letters 9:259-264 (1987)) demonstrated that various soluble iron compounds, such as ferric citrate, could be used in place of transferrin in the culture of hybridoma cell lines. Kovar and Franek tested the ability of ferric citrate to support the growth of two hybridoma cell lines over a concentration range of 5 μM (1.25 mg/L) to 5 mM (1225 mg/L). Although lower concentrations of ferric compounds had been proposed in earlier prior art to be suitable for use in culture media for several different cell lines (in particular those of human leukaemic or epithelial origin), Kovar and Franek report that if ferric citrate was to support hybridoma cell growth with equivalence to transferrin, it was required at a concentration of 500 μM (122.5 mg/L). Kovar and Franek found that the medium containing 500 μM ferric citrate was suitable for the culture of other hybridoma cell lines and was also suitable for the culture of several myeloma cell types.
Eto, et al., (Agric. Biol. Chem. 55(3):863-865 (1991)), report similar findings to Kovar and Franek. These workers tested the growth stimulating effect of ferric citrate over a concentration range of 10 mg/L to 600 mg/L on a hybridoma cell line. They report that 300 mg/L was used for further studies. Growth equivalent to that achieved with transferrin was observed when ethanolamine (a lipid precursor) was added at a concentration of 10 μM to the medium containing 300 mg/L ferric citrate.
In a similar study, Toyoda & Inouye, (Agric. Biol. Chem. 55(6):1631-1633 (1991)), tested the growth of three hybridoma cell lines in media containing ferric citrate over a concentration range of 0 to 500 μM. They report that for two of the three hybridoma cell lines tested, 50 μM (12.5 mg/L) ferric citrate was found to be optimal. This result is contrary to the findings of Eto et al., and Kovar and Franek, although a concentration of 500 μM was found optimal for the third cell line.
It is, however, important to note that the work of Kovar & Franek, Toyoda & Inouye, and Eto et al. was all carried out in static culture. WO 94/02592 reports that although 10 mg/L ferric ammonium citrate (FAC) was able to support hybridoma growth in static culture, this was not the case in agitated suspension culture. It is apparent, therefore, that the ability of hybridoma cells to make optimal use of the iron when grown in agitated suspension culture is different from that in static culture.
WO 93/00423 describes a culture medium additive comprising an iron chelate of a soluble iron salt and an alkali metal or alkaline earth metal citrate which is a suitable iron source for serum-free of protein-free culture media. The Examples of this application are concerned predominantly with the growth of mammalian cells such as BHK and CHO cells. Although Example 5 purports to demonstrate the growth of myeloma cells, it is noted that the SP2/0 cells used are in fact non-secreting mouse/mouse hybridoma cells. Culture conditions are specified throughout as being static suspension culture.
Kovar and Franek claim that their medium containing 500 μM ferric citrate was suitable for agitated suspension culture but show no evidence to support this claim. Qi et al., (Cytotechnology 21:95-109 (1996)), however, report that a medium containing 500 μM (122.5 mg/L) ferric citrate, as described by Kovar and Franek, was suitable for the culture of three hybridoma cell lines in agitated suspension cultures. However, Qi et al. found that in order to use a medium containing these high concentrations of ferric citrate (500 μM), it was necessary to wean the cells onto this medium; in the case of one cell line this weaning period was highly protracted. Qi et al. comment that under these conditions the cells were experiencing difficulty adapting and that the medium formulation could be improved by substitution of the ferric citrate in the medium with a more efficient iron presenting compound such as aurin tricarboxlic acid.
In agreement with the prior art cited by Kovar and Franek (1987), several workers have reported that certain types of mammalian cell have been found to be sustainable in culture using lower concentrations of iron compounds.
Ramos et al., WO 92/05246, reports that in the cultivation of epithelial cell lines and in particular Chinese Hamster Ovary (CHO) cell lines, transferrin can be replaced with ferric citrate at 10-100 mg/L (providing approximately 0.6-16 mg/L iron). However, this patent application states clearly that the medium was found not to be suitable for the culture of myeloma cell lines. Keen et al., U.S. Pat. No. 5,633,162, report that ferric citrate, ferrous sulphate and ferric ammonium citrate (FAC) can be used at concentrations of between 0.25 and 5 mg/L (equivalent to 0.04 to 0.8 mg/L iron) to replace transferrin in the culture of CHO cells. WO 98/08934 defines a replacement medium in which all animal proteins, i.e. transferrin and insulin, have been replaced. Transferrin was replaced by ferrous sulphate chelated to a nitrogen-containing chelating compound at concentrations, based on iron, of between 0.28 and 11 mg/L, with 1.1 mg/L being found to be optimal. The nitrogen containing chelating compounds stated as suitable include: ethylenediaminetetraacetic acid (EDTA); ethyleneglycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA); desferoxamine mesylate; diethylenetriaminepentaacetic acid (DTPA) and trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CDTA). Of these, EDTA is the most preferred. Ferric citrate was also used in the form of FeCl3-sodium citrate, but this was required at higher concentrations than the ferrous sulphate.7H2O-EDTA chelate.
This application states that the transferrin free medium is suitable for growing mammalian cells, particularly epithelial or fibroblast cells. Exemplification of the growth of CHO and the human embryonic kidney cell line 293 has been provided.
A range of cell types were also tested by Neumannova et al., (In vitro Cell Dev. Biol., 31:625-632 (1995)) for long term growth in media containing iron in the form of ferric citrate at the low concentration of 1.25 mg/L (approximately 0.2 mg/L iron). Of the 19 cell lines tested only 5 were capable of long term growth in this low iron medium. The 5 cell lines were Jurkat, J111 and THP-1 (human leukaemia cell lines), HeLa (a human epithelial cell line) and XC (a rat sarcoma). Although hybridoma and myeloma cell lines were included amongst those tested, none was found to be able to grow in the low iron medium.
As discussed above, lower concentrations of ferric compounds are suitable for use in culture media for certain cell types (particularly those of epithelial and human leukaemic origin). It is, however, generally agreed In the art that, in order to cultivate hybridoma cells in agitated suspension culture using a transferrin free medium, a high concentration, for example in the region of 122.5 mg/L, of an iron compound is required.
The prior art also teaches, however, that high concentrations of iron are not advantageous. Bertheussen, in Cytotechnology 11:219-231(1993), states that high concentrations of iron, such as the 500 μM ferric citrate suggested by Kovar and Franek, should not be used as these high concentrations cause rapid precipitation of iron hydroxide in the medium. Freshly formed iron hydroxide absorbs other metals and various organic molecules efficiently, thus the composition and stability of media containing high iron will be seriously affected.
In view of the difficulties encountered in delivering iron to certain mammalian cells in culture, in particular to hybridoma cells, the concept of chelation of the iron, e.g. to lipophilic compounds was developed.
Iron chelators are typically heterocyclic compounds which attach the metal ion by co-ordinate bonds to at least two non-metal ions in the chelator, and they can be classified using a number of criteria such as their origin (synthetic or biologically produced molecules), their interaction with solvents such as water (hydrophobic vs hydrophilic) or their stochiometric interaction (bidentate of hexadentate).
Lipophilic chelators are compounds which have two distinct properties: (1) the compounds are hydrophobic and often aromatic, thus exhibiting solubility in organic solvents (e.g. alcohol) but limited solubility in water; (2) the compounds also, typically, have a region of negative charge which allows "binding" of iron through electrostatic interactions with positively charged iron ions. In cell culture, it is thought that such compounds will be attracted to the lipid rich membranes of the cells and will, therefore, transport "bound" iron to and possibly through the cell membrane, thus facilitating the supply of iron to the cells (U.S. Pat. No. 5,045,468). The lipophilic chelators are typically added in excess of an accompanying iron salt.
One of the earliest reports of the use of a lipophilic chelator was by Brock and Stevensen (Immunology Letters 15:23-25, (1987)) who used pyridoxal isonicotinoyl hydrazone (PIH) in conduction with ferric nitrilotriacetate. They found that PIH:ferric nitrilotriacetate at a ratio of 2:1 and a concentration of 40 μM (based on PIH) could replace transferrin for the culture of mouse lymphocyte cell lines.
Darfler, (U.S. Pat. No. 5,045,468/in Vitro Cell. Dev. Biol. 26:769-778, 1990) reports a protein free medium suitable for the culture of hybridoma cell lines. The author found that transferrin could be replaced by using the organo iron compound, sodium nitroprusside (SNP) together with EDTA at concentrations of 5.7 and 5.5 mg/L respectively. The author named this medium "ABC medium".
Bertheussen, (U.S. Pat. No. 5,045,467/Cytotechnology 11:219-231 (1993)), reported that the transferrin in cell culture media could be replaced by using aurin tricarboxlic acid, a lipophilic iron chelator, and 3 μM ferric ions (added in the form of FeCl3). Bertheussen developed this medium using several cell types and found it especially suitable for the culture of fast growing hybridoma cell lines.
WO 94/02592 proposed that tropolone be used to replace the function of transferrin in the presentation of iron to cells in agitated suspension culture. The author comments that tropolone should be added in excess of accompanying iron. The iron may be presented as ferric or ferrous ions using a variety of iron compounds, with FAC the most preferred. A hybridoma cell line was used to elucidate the optimum concentrations of tropolone and FAC as 5 μM and 0.2 mg/L respectively. This medium was also suitable for the growth of NSO myeloma cells. Purely as experimental controls, media lacking transferrin and tropolone but containing FAC were tested with hybridoma and myeloma cells. It was found that FAC alone, between 0.1 and 10 mg/L, was incapable of supporting the growth of hybridoma cells in agitated suspension culture. FAC alone at a concentration of 0.2 mg/L could not support the growth of the NSO myeloma cell lines. No other concentrations of FAC alone were investigated with the myeloma cell lines: presumably the authors assumed that NSO and hybridoma cell lines behave similarly and did not expect other concentrations of FAC to support cell growth.
Keen (Cytotechnology 17:193-202, 1995) reports the development of a protein free medium for the culture of rat myeloma and rat hybridoma cells. This medium, called W38, was based on a 1:1:1 mixture of DMEM, RPMI and the ABC medium developed by Darfler. The medium therefore contained SNP as a lipophilic source of iron and EDTA as a nitrogen containing chelator. SNP and EDTA were, however, at ⅓ of the concentration found in the ABC medium, and Keen found it beneficial to increase the iron concentration by including ferric citrate in the medium. W38 medium was also suitable for the cultivation of the cholesterol auxotrophic myeloma cell line, NS0, providing suitable provision for the cholesterol requirement was made (Keen and Steward, Cytotechnology 17:203-211, 1995).
A recent patent application by Epstein et al., WO 01/16294, comments that in many cases simple iron carriers such as citrate do not provide sufficient iron availability to, or uptake by, cultured cells. The patent also reports that a range of lipophilic iron chelating compounds could be used for a variety of cell types with differing degrees of success. However, results at least as good as transferrin were only obtained with sorbitol chelated to FeCl3 and 2-hydroxypyridine-N-oxide.
The use of lipophilic compounds to chelate and aid presentation of iron in transferrin free culture of hybridoma and myeloma cell types has therefore become state of the art. There are, however, several disadvantages to the inclusion of lipophilic chelators in cell culture medium. The lipophilic chelators are often toxic, for example SNP is classified as highly toxic and has an LD50 in rat of <1 mg/kg. In cell lines used for the industrial production of biotherapeutic products, this has consequences for both manufacturing operators and the final product. Indeed, it may be necessary to develop and validate assays to prove that the final purified biotherapeutic product is clear of any contaminating lipophilic chelator. Additionally, optimisation of the iron concentration of any particular process will be further complicated due to the two-component system of chelator and iron compound.
In summary, the prior art shows that:                1. in the absence of transferrin, hybridoma and myeloma cells will grow in high iron concentrations (122.5 mg/L ferric citrate) (Kovar & Franek).        2. high iron concentrations (e.g. 122.5 mg/L ferric citrate) cause precipitation which damages the culture medium (Bertheussen).        3. in the absence of transferrin or a lipophilic chelator, hybridoma cells will not grow in agitated culture and myeloma cells will not grow at all in low iron concentrations (0.1-10 mg/L and 0.2 mg/L respectively) (WO 94/02592).        4. a lipophilic chelator is required in the medium to enable hybridoma and myeloma cells to grow in agitated culture in low iron concentrations (WO 94/02592).        5. low iron concentrations can be used for growth of certain mammalian cells, but only with the use of a nitrogen-containing chelator such as EDTA (WO 98/08934).
Within the art of cell culture It is appreciated that certain cell types share similar nutritional attributes. It is notable that both myeloma and hybridoma cell types share significant attributes that are not always exhibited by other cell types, for example glutamine auxotrophy (Bebbington et al. Biotechnology 10:169-175, 1992). The fact that hybridomas and myelomas react in a similar way in many respects is, to a certain extent, unsurprising since hydridoma cell lines are produced by fusion of a myeloma cell with an antibody producing B lymphocyte (Kohler and Milstein, Nature 256:495-497, 1975).
The prior art, as outlined above, has shown that the ability of hybridoma and myeloma cells to use iron present in the medium with a simple iron carrier, such as a citrate, and in the absence of transferrin or a lipophilic or nitrogen-containing chelator is different from the corresponding ability of, for example, CHO cells. The overall teaching of the prior art is that hybridoma and myeloma cells are the same in their ability to use iron in a transferrin-free culture medium.
It is apparent from the literature, as discussed above, that time and effort have been dedicated to the development of transferrin free media for the growth of hybridoma cell types, particularly in static culture. On the art-implied assumption that myeloma cells will demonstrate the same requirements as hybridoma cells in this respect, an equivalent effort has not been made with myeloma cells.
Over the years, it is apparent that the art of hybridoma and myeloma cell culture has moved away from the use of iron in the form of a soluble iron compound as a replacement for transferrin, and instead has determined that to reap the benefits of low iron concentrations, a lipophilic or nitrogen-containing chelator must be included in a culture medium. Of course the use of such chelators in media used to grow cells for the product they have been engineered to produce, also necessitates that the product is further treated to ensure there is no contamination with that chelator. The inclusion of such a chelator in the culture medium thus not only extends the time taken to demonstrate that the product is pure, but also increases the expense of production by necessitating development of specific assays to prove that a "toxic" iron chelator does not contaminate the pure product.
It is apparent, therefore, that a need still exists to provide iron in a simple form to certain cells in culture at concentrations which will provide sufficient iron to enable continuing cell growth but which will not result in the precipitative damage discussed above. A further advantage would be to have a medium free of transferrin and lipophilic or nitrogen-containing chelators. The aim would be to achieve equivalent cell culture in a transferrin and lipophilic or nitrogen-containing chelator-free medium as would be obtained in a medium containing transferrin.

Myeloma cell culture in transferrin-free low iron medium


In a so-called GTL process for producing liquid hydrocarbons containing fuel oil by producing synthesis gas from natural gas, subsequently producing Fischer-Tropsch oil from the obtained synthesis gas by way of Fischer-Tropsch synthesis and upgrading the produced Fischer-Tropsch oil, the synthesis gas produced from a synthesis gas production step is partly branched at a stage prior to getting to a Fischer-Tropsch oil production step and high-purity hydrogen is separated and produced from the synthesis gas entering the branch line. All the separated high-purity hydrogen is supplied to an upgrading reaction step and consumed as hydrogen for an upgrading reaction. Additionally, the synthesis gas entering the branch line is subjected to a water gas shift reaction to raise the hydrogen concentration before the step of separating and producing high-purity hydrogen and the residual gas left after the separation may be circulated to the synthesis gas production step as raw material for producing synthesis gas.

A so-called GTL process for producing liquid hydrocarbons that contain fuel oil from natural gas is described, for example, in WO 2007/114274 A1. FIG. 3 of the accompanying drawings is a schematic illustration of the flow of such a known GTL process.
The GTL process illustrated in FIG. 3 includes a hydrodesulfurization step 120 of hydrodesulfurizing sulfur compounds in natural gas, a synthesis gas production step 130 of producing synthesis gas by way of a reforming reaction of natural gas with steam and/or carbon dioxide, a carbon dioxide removal step 140, which is provided whenever necessary, a Fischer-Tropsch oil production step 150 of producing Fischer-Tropsch oil from the synthesis gas by way of Fischer-Tropsch (FT) synthesis, an upgrading reaction step 160 of hydrogenating the produced Fischer-Tropsch oil and an upgrading gas/liquid separation step 170 of subjecting the hydrogenated product obtained by the upgrading reaction step to gas/liquid separation to obtain liquid hydrocarbons, the above steps being arranged sequentially from the natural gas feed side (or the upstream side) or from the left side in FIG. 3.
The synthesis gas produced from the synthesis gas production step 130 partly branches off at a stage prior to getting to the Fischer-Tropsch oil production step 150 to form a branch line 145 and the synthesis gas in the branch line 145 is separated into high-purity hydrogen (line 192) and purge gas (line 191) in a hydrogen separation step 190 typically by means of a hydrogen PSA (pressure swing adsorption) method. The separated high-purity hydrogen partly joins a hydrogen circulation line 177, by way of lines 192 and 197, where hydrogen circulates from the upgrading gas/liquid separation step 170 to the upgrading reaction step 160, while the remaining part is supplied to a hydrodesulfurization step through a line 196. On the other hand, the purge gas that is purged from the line 191 is normally consumed as fuel.
In the above-described known process, the concentration of hydrogen supplied to the upgrading reaction step 160 is about 92 mol %. If the concentration of hydrogen supplied to the upgrading reaction step 160 can be raised from the level of the prior art, the pressure required for the hydrogenation reaction of the upgrading reaction step 160 can be reduced to reduce the operation cost. Additionally, the reaction efficiency is improved to make it possible to reduce the size of the reactor for the upgrading reaction step 160. Furthermore, the step can be conducted at a lower reaction temperature to suppress deactivation of the catalyst and increase the catalyst life.
Since the purge gas 191 discharged from the hydrogen separation step 190 contains unreacted methane, a significant improvement can be achieved in terms of raw material consumption per product to an economic advantage if it can be taken into the process once again and reutilized as raw material.
However, there is not any technique proposed to date to dissolve the above-identified problem and realize a realistic process for treating such purge gas.

Production method of liquid hydrocarbons from natural gas

Japan Oil, Gas and Metals National Corporation


An assembly for moving a barrier from one of a closed position and an opened position to the other of the closed position and the opened position. The assembly includes a motor to supply one of a first power and a second power to the barrier. The assembly also includes a controller to control the motor to supply the first power to move the barrier towards the closed position from the opened position. The controller also controls the motor to supply the first power to the barrier to move towards the opened position from the closed position, and to supply the second power intermittently after the barrier has started moving towards the opened position and before arriving at the opened position.

The present invention relates to barriers, and more particularly to a control system for a barrier such as a garage door.
A typical barrier, such as a garage door, can be can be lowered to a closed position and lifted to an opened position by a motor during a closing cycle and an opening cycle, respectively. During the closing cycle, the motor generally lowers the barrier with a first predetermined amount of power. During the opening cycle, the motor generally lifts the barrier with the same first predetermined amount of power. For example, the first predetermined amount of power can be ½ horsepower ("hp").
When the barrier is heavy, the motor is typically configured differently to overcome a different moment of inertia. That is, the motor is configured to lift the barrier with a second predetermined amount of power that is typically greater than the first predetermined amount of power. In such cases, the second predetermined amount of power can be ¾ hp. However, starting and lifting the barrier at high power such as ¾ hp can lead to excessive mechanical shock to the barrier. As a result of the excessive mechanical shock to the barrier, the barrier and its mounting hardware can be damaged over time.

Assembly for moving a barrier and method of controlling the same


A ferrule holder assembly for an optical-fiber-end-face grinding apparatus comprises a ferrule holder board supported to be moved upward and downward in parallel with a grinding board of the optical-fiber-end-face grinding apparatus, a ferrule sleeve provided at the ferrule holder board for receiving and supporting an optical fiber ferrule while putting the tip at the grinding board, an adapter for retaining the optical fiber ferrule or a connector for supporting the optical fiber ferrule in a state where the optical fiber ferrule is inserted into the ferrule sleeve, and an urging unit for urging the adapter in a direction opposite to the grinding board from the ferrule holder board.

1. Field of the Invention
The present invention relates to a ferrule holder assembly for an apparatus for grinding end faces of a plurality of ferrules with optical fibers simultaneously.
2. Description of the Related Art
It is well known by those skilled in the art that in order to connect optical fibers together while reducing connection loss and reflected returned light, tips of ferrules are ground by perpendicular or inclined spherical grinding to connect the optical fibers together. The shape of the convex spherical surface in this case is standardized by the international standard (IEC: International Electrotechnical Commission No. 60874-14-6) or the like. U.S. Pat. No. 5,351,445 discloses a technique of apparatus for grinding end faces of a plurality of optical fibers simultaneously. A ferrule holder of this grinding apparatus projects tips of ferrules from a plurality of insertion holes (sleeves) thereof to a grinding board by a specified amount and supports the ferrules. Grinding is performed by revolving a grinding film put on an elastic plate of the grinding board by an autorotational and orbital motion mechanism of the grinding apparatus and applying a specified amount of pressure to a grinding jig on which a plurality of ferrules with the optical fibers are mounted. Thus, the shape of the tips of the ferrules of the optical fibers can be made convex spherical surface that satisfies the standard.
Even if a similar type of ferrule or connector is used, however, variation in length exists within a dimensional tolerance and the size differs depending on the manufacturer. Therefore, when a plurality of ferrules or connectors are mounted on the ferrule holder, it is difficult that all the tips of the ferrules are projected by a specified amount and supported.
Although a reference plane of the ferrule holder for mounting the ferrule for grinding is processed to have a specified height with a strict tolerance, since the reference plane for mounting the plurality of ferrules is fixed, the heights of the tips of the ferrules from the insertion holes vary by an amount of variation in length of ferrules or housings of the ferrules.
When the plurality of end surfaces of the optical fiber connectors of a lot in which the lengths of ferrules vary are simultaneously ground, since the grinding holder is directly weighted in the conventional grinding apparatus, problems occur in that the holder is tilted due to the variation in projection amount therefrom to generate a deviation from the shaft axis, or the ferrules having a small projection amount are insufficiently ground. Therefore, in the method of the conventional grinding apparatus, it is necessary to perform preliminary grinding up to a shortest ferrule and then to perform grinding again from a state in which the ferrules have the same height.

Ferrule holder assembly for optical-fiber-end-face grinding apparatus


An interconnecting structure in which circuit and componentry bearing cards are retained in contact with an intermediate card that has component and circuitry areas, and socket insertion contacts.

As component densities and signal rates increase, it has become of importance to arrange the circuitry into as dense a structure as possible while still retaining ability to conduct repair and maintenance operations. There has developed in the art a structural system wherein the components, such as integrated circuit devices, are mounted on generally insulating planar members with printed wiring interconnecting the component terminals and with terminals along an edge of the planar member. The component and printed wiring bearing planar members have become known in the art by such terms as boards, modules and cards. For consistency, the term card will be used. These cards are both rigid and flexible. The edge of the card, in turn, fits into a socket that makes an electrical interconnection between each terminal along the edge of the card and external circuitry in the overall electronic apparatus so that the cards are parallel to each other and perpendicular to the socket.
Progress in the art is encountering several interrelated limitations. As component density and capability increase, the number of terminals on the edge of the card increases which results in closer spacing. The sockets into which the edges of the card fit must be strong enough to support the card and do it with electrically reliable contact on each terminal which results in socket structural limits on both the number of contacts on a card edge and the closeness of the cards. As component capability increases, it becomes necessary to combine several cards into an overall electrical function and when this is done, fan-out wiring or combinatorial switching or logic circuitry is needed.
There has been some progress in the art on a portion of the limitations. The high density contacting limitation has been addressed through the zero insertion force technique wherein in essence a separate force from the insertion force supplies the contact pressure. One example of such a structure is shown in U.S. Pat. No. 3,992,653 wherein cam actuated lateral pressure is applied after card insertion. Another example is shown in U.S. Pat. No. 4,834,660 wherein the contacts on the card edge extend around a resilient member on the card edge and contact pressure is applied through bolts that pull the contacts and the socket together.

International Business Machines Corporation


A saddle-type vehicle has an engine-fastening structure which stabilizes a seating face contact between a collar and a vehicle body frame on one side, and between the collar and an engine on the other side. The vehicle includes a vehicle body frame having an engine-supporting portion, and an engine block having a female threaded portion formed therein for alignment with the engine-supporting portion. The collar is interposed between the engine-supporting portion and the engine block. The engine-supporting portion of the frame, the collar and the engine side female threaded portion are fastened together by a bolt. A gap is provided at least at locations between the collar and the bolt which oppose a boundary between the collar and the engine-supporting portion, and another boundary between the collar and the engine side female threaded portion.

1. Field of the Invention
The present invention relates to a connection arrangement between a frame member and an engine of a saddle-type vehicle, and to a vehicle incorporating the same. More particularly, the present invention relates to an engine-fastening structure of a saddle-type vehicle, and a vehicle incorporating the same.
2. Description of the Background Art
In a motorcycle, which is one example of a saddle-type vehicle, normally the engine is a component having the highest weight. It is known that fastening of the engine and a frame to each other is a significant factor in setting for vibrations and traveling behaviors, as discussed in the Japanese Patent Laid-Open No. 2005-014885.
For example, it is well known that vibrations or the rigidity of a finished vehicle varies depending upon whether rigid mounting or rubber mounting is used for an engine. In a motorcycle wherein an engine is mounted on a frame by rigid mounting, the engine and the frame are fastened to each other with a collar interposed therebetween. The collar can make relative displacement to the bolt by a very small distance in a diametrical direction because a clearance of approximately 0.3 mm exists between the collar and the fastening bolt.
The relative displacement between the collar and the bolt is suppressed by friction between a frame side seating face and an engine side seating face upon which axial force of fastening acts. In a motorcycle which adopts the rigid mounting, the contact state of the components mentioned is maintained with certainty to achieve stabilization of vehicle body vibration and the control performance.
If a motorcycle wherein an engine having high weight is rigidly mounted through a collar travels on a road having a large gap, then the vehicle undergoes upward and downward vibrations, and a load higher than holding force of the contact seating faces at the opposite ends of the collar may be generated at the fastening portions and the fastening bolt may undergo shearing deformation and may be plastically deformed by a very small amount.
If the fastening bolt is plastically deformed, then variation of the contacting portions of the frame, collar and engine and variation in contact pressure distribution of the seating faces occur. This sometimes results in failure in stabilized seating face contact and in variation of vibrations or the drivability.
In such an instance, the structure of the fastening portion between the frame and the engine is set appropriately in accordance with the vehicle. In the prior art document, a structure is disclosed wherein, in an engine supporting structure for a motorcycle where a collar is interposed between a frame and an engine, wedge-like projections are provided on opposite end seating faces of the collar.
With a structure such as described above, it is possible to effectively suppress the relative displacement between the collar and the bolt.
However, according to the conventional structure, the cost required for working of the collar is high. Further, positioning in a circumferential direction of the collar is required, and time and labor are required for assembling these components.
The present invention has been made in view of the situation described above. Accordingly, it is one of the objects of the present invention to provide a saddle-type vehicle having an engine-fastening structure which stabilizes seating face contact between a frame and a collar, and between an engine and the collar and is low in cost and easy in fastening working.

Connection structure arrangement between a frame member and an engine of a saddle-type vehicle, and vehicle incorporating same


Implementations of a static discharge station are provided. In some implementations, the static discharge station may be employed by a user to discharge a build-up of static electricity prior to pumping gas. In some implementations, the static discharge station may have advertising thereon. In this way, a user or a passerby may be exposed to the displayed advertisement(s). In some implementations, the static discharge station may be comprised of a body portion having a button thereon, a support pole, a base, a wire, and a grounding rod. In some implementations, the button may be configured to selectively make contact with the support pole of the static discharge station. In some implementation, a user may discharge a static electricity build-up by touching the button. In this way, the static build-up may travel through the button, support pole, base, and wire into the grounding rod. In some implementations, the base may serve to ground the static discharge station without the use of a wire and/or grounding rod.

Gas pumps are nearly ubiquitous throughout our society and the hazards of static electricity around gas pumps are well known. For example, a single spark may ignite flammable gas fumes causing a fire and/or explosion.
U.S. Pat. No. 7,068,488 ("'488 patent") discloses a static discharging system having an electrically conductive plate attached to the upper end of a post. The lower end of the post is mounted in the ground adjacent a gas pumping station. The '488 patent teaches to secure one end of an electrical conduit to the eclectically conductive plate and to insert the other end into the ground. The '488 patent then teaches to discharge a static build-up by making physical contact with the electrically conductive plate.
However, the static discharging system has several disadvantages. First, the static discharging system is not configured for the placement of advertisements thereon. As a result, the opportunity to advertise to the user of the static discharging system is lost. Second, the conductive plate may not be suitable for discharging static electrical build-up if it is covered by advertisements which insulate the plate.


Plant metabolism and alkaloid levels can be regulated by transcription factors that regulate the nicotinic alkaloid biosynthetic pathway. In one embodiment, the disclosure provides a transcription factor that negatively regulates alkaloid biosynthesis, such as nicotine biosynthesis.

Many plant natural products have biological activities that make them valuable as pharmaceutical drugs. Alkaloids are a class of natural products that have proved particularly useful as drugs and medicines. Examples of biologically-active alkaloids include morphine, scopolamine, camptothecin, cocaine and nicotine. These compounds are all isolated from plant sources for use as pharmaceutical drugs. Nicotine, morphine (and related opiates) and cocaine are also addictive drugs that are responsible for significant health and societal problems worldwide.
Nicotine is a pyrrolidine alkaloid that exhibits a range of bioactivities, including potent toxicity and nervous system stimulation. In Nicotiana tabacum, N. benthamiana and a number of other species, nicotine is synthesized in the roots and then transported to the leaves, where it appears to play a role in defense. The biosynthesis of nicotine and many other plant metabolites can be induced by the application of a class of volatile plant hormones collectively termed jasmonates (Gundlach et al., Proc. Natl. Acad. Sci. U.S.A. 89: 2389-2393 (1992)). Although increases in nicotine levels can be induced by wounding or jasmonate application, the actual regulatory machinery responsible for this induction has yet to be discovered.
Plant natural product biosynthesis is mainly under transcriptional control, which allows plants to regulate metabolism in a developmental and stress-specific fashion. A number of transcription factors that regulate specific branches of secondary metabolism have been identified in plants. Anthocyanin biosynthesis is controlled by interacting MYB proteins (e.g. maize C1, Arabidopsis PAP1/PAP2) and basic-helix-loop-helix proteins (e.g. maize R, petunia AN1) (for a review see Vom Endt et al., Phytochemistry 61: 107-114 (2002)). Examples of other transcription factors regulating plant metabolic processes include a WRKY-type transcription factor that appears to control the transcription of a sesquiterpene synthase in cotton trichomes (Xu et al., Plant Physiol. 135: 507-515 (2004)) and an AP2/ERF-like transcription factor, WIN1, that up-regulates wax biosynthesis in Arabidopsis (Broun et al., Curr. Opin. Plant Biol. 7: 202-209 (2004)).
Overexpression of ORCA3 in Catharanthus roseus cell suspensions increased levels of transcripts of genes encoding some of the enzymes in the C. roseus terpenoid indole alkaloid pathway, but alkaloid accumulation was observed only when the cell suspension were provided with loganin, a terpenoid precursor. (van der Fits and Memelink. Science 289:295-297 (2000)). Overexpression of two transcription factors, NtORC1 and NtJAP1, increased transient expression of marker genes linked to a putrescine N-methyltransferase (PMT) promoter in tobacco cell suspensions. (De Sutter et al., Plant J. 44:1065-76 (2005))

Nucleic acid sequences encoding transcription factors regulating alkaloid biosynthesis and their use in modifying plant metabolism


Disclosed herein is an apparatus for detecting locations of a vehicle and an obstacle. The apparatus for detecting locations of a vehicle and an obstacle includes at least one distance measurement unit and a data processing unit. The distance measurement unit measures distance data relevant to a vehicle and an obstacle within a measurement area. The data processing unit maps the distance data on a grid layer, detects the location of the vehicle based on the result of the mapping, detects the location of the obstacle based on the detected location of the vehicle, and modifies the detected location of the vehicle using the distance data.

1. Technical Field
The present invention relates generally to an apparatus and method for detecting the locations of a vehicle and an obstacle and, more particularly, to an apparatus and method for detecting the locations of a vehicle and an obstacle using a laser scanner.
2. Description of the Related Art
An unmanned autonomous vehicle detects an obstacle in such a way as to mount radar, laser radar (lidar) and image sensors on a vehicle, and detects a current location in such a way as to mount a high performance Global Positioning System (GPS), thereby performing unmanned autonomous travel.
However, since sensors mounted on a vehicle can be used only for the corresponding vehicle, it is troublesome to mount sensors on all unmanned vehicles in order to operate a plurality of unmanned vehicles.
A high performance GPS has the disadvantage of the usable area thereof being restricted to open space since GPS signals might be interrupted by buildings and roofs. Further, since a high performance GPS is an expensive apparatus, there is a problem in that the price of the whole unmanned vehicle system rises.

Apparatus and method for detecting locations of vehicle and obstacle

Electronics and Telecommunications Research Institute


A new and distinct cultivar of Gypsophila plant named ‘Esm Cirque’, characterized by its erect and strong flowering stems; early, uniform and freely flowering habit; double luminous white-colored flowers; and good postproduction longevity.

The present invention relates to a new and distinct cultivar of Gypsophila plant, botanically known as Gypsophila hybrida, grown commercially as a cut flower, and hereinafter referred to by the name 'Esm Cirque'.
The new Gyposphila is a product of a planned breeding program conducted by the Inventor in El Quinche, Pichincha, Ecuador. The objective of the breeding program is to create new freely flowering Gyposphila cultivars with many petals per flower and straight stems.
The new Gypsophila originated from a cross-pollination made by the Inventor in El Quinche, Pichincha, Ecuador in August, 2003 of a proprietary selection of Gypsophila hybrida identified as Line 114, not patented, as the female, or seed, parent with a proprietary selection of Gypsophila hybrida identified as Line 56, not patented. The cultivar Esm Cirque was discovered and selected by the Inventor as a flowering plant from within the progeny of the state cross-pollination in a controlled environment in El Quinche, Pichincha, Ecuador.
Asexual reproduction of the new Gyposphila by cuttings in a controlled environment in El Quinche, Pichincha, Ecuador since August, 2004, has shown that the unique features of this new Gypsophila are stable and reproduced true to type in successive generations.


A multiple pass optical cell and method comprising providing a pair of opposed cylindrical mirrors having curved axes with substantially equal focal lengths, positioning an entrance hole for introducing light into the cell and an exit hole for extracting light from the cell, wherein the entrance hole and exit hole are coextensive or non-coextensive, introducing light into the cell through the entrance hole, and extracting light from the cell through the exit hole.

1. Field of the Invention (Technical Field)
The present invention relates to creation and use of long folded optical paths in a compact structure for use with lasers in making optical measurements or systems.
2. Description of Related Art
Note that the following discussion refers to a number of publications by author(s) and year of publication, and that due to recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
Multiple pass optical cells with dense spot patterns are very useful for many applications, especially when the cell volume must be minimized relative to the optical path length. Present methods to achieve these dense patterns require very expensive, highly precise astigmatic mirrors and complex alignment procedures to achieve the desired pattern. This invention describes a new, much simpler and less demanding mirror system comprising inexpensive cylindrical mirrors which can meet all of the requirements and be aligned much more readily.
Multiple pass optical cells are used to achieve very long optical path lengths in a compact footprint and have been extensively used for absorption spectroscopy, (White, J. U., "Long Optical Paths of Large Aperture," J. Opt. Soc. Am., vol. 32, pp 285-288 (May 1942); Altmann, J. R. et al., "Two-mirror multipass absorption cell," Appl. Opt., vol. 20, No. 6, pp 995-999 (15 Mar. 1981)), laser delay lines (Herriott, D. R., et al., "Folded Optical Delay Lines," Appl. Opt., vol. 4, No. 8, pp 883-889 (August 1965)), Raman gain cells (Trutna, W. R., et al., "Multiple-pass Raman gain cell," Appl. Opt., vol. 19, No. 2, pp 301-312 (15 Jan. 1980)), interferometers (Herriott, D. H., et al., "Off-Axis Paths in Spherical Mirror Interferometers," Appl. Opt., vol. 3, No. 4, pp 523-526 (April 1964)), photoacoustic spectroscopy (Sigrist M. W., et al., "Laser spectroscopic sensing of air pollutants," Proc. SPIE, vol. 4063, pp. 17 (2000)) and other resonators (Yariv, A., "The Propagation of Rays and Spherical Waves," from Introduction to Optical Electronics, Holt, Reinhart, and Winston, Inc., New York (1971), Chap. 2, pp 18-29; Salour, M. M., "Multipass optical cavities for laser spectroscopy," Laser Focus, 50-55 (October 1977)).
These cells have taken the form of White cells (White, J. U., "Long Optical Paths of Large Aperture," J. Opt Soc. Am., vol. 32, pp 285-288 (May 1942)), integrating spheres (Abdullin, R. M. et al., "Use of an integrating sphere as a multiple pass optical cell," Sov. J. Opt. Technol., vol. 55, No. 3, pp 139-141 (March 1988)), and stable resonator cavities (Yariv, A., "The Propagation of Rays and Spherical Waves," from Introduction to Optical Electronics, Holt, Reinhart, and Winston, Inc., New York (1971)).
The stable resonator is typified by the design of Herriott (Herriott, D. H., et al., "Off-Axis Paths in Spherical Mirror Interferometers," Appl. Opt., vol. 3, No. 4, pp 523-526 (April 1964)). The simplest such Herriott cell consists of two spherical mirrors of equal focal lengths separated by a distance d less than or equal to four times the focal lengths f of the mirrors. This corresponds to stable resonator conditions. A collimated or focused laser beam is injected through the center of a hole in one of the mirrors, typically an off-axis location near the mirror edge. The beam is periodically reflected and refocused between these mirrors and then exits through the center of the input hole (defining the re-entrant condition) after a designated number of passes N, in a direction (slope) that is different from the entry slope. As a result, the total optical path traversed in the cell is approximately N×d. The pattern of reflected spots observed on the mirrors in these cells forms an ellipse. Re-entrant conditions for spherical mirror Herriott cells are restricted by certain predetermined ratios of the mirror separation d to the focal length f and the location and slope of the input beam. For any re-entrant number of passes N, all allowed solutions are characterized by a single integer M. Excellent descriptions for the design, setup and use of these cells are given by Altmann (Altmann, J. R., et al., "Two-mirror multipass absorption cell," Appl. Opt., vol. 20, No. 6, pp 995-999 (15 Mar. 1981)) and McManus (McManus, J. B., et al., "Narrow optical interference fringes for certain setup conditions in multipass absorption cells of the Herriott type," Appl. Opt., vol. 29, No. 7, pp 898-900 (1 Mar. 1990)).
When the cell volume must be minimized relative to the optical path length or where a very long optical path (>50 m) is desired, it is useful to increase the density of passes per unit volume of cell. The conventional spherical mirror Herriott cell is limited by the number of spots one can fit along the path of the ellipse without the spot adjacent to the output hole being clipped by or exiting that hole at a pass number less than N. This approximately restricts the total number of passes to the circumference of the ellipse divided by the hole diameter, which in turn is limited by the laser beam diameter. For a 25-mm radius mirror with a relatively small 2-mm diameter input hole located 20 mm from the center of the mirror, a maximum of about (π×2×20)/2≈60 spots, or 120 passes is possible at best. Generally the hole is made larger to prevent any clipping of the laser input beam that might lead to undesirable interference fringes, and typical spherical Herriott cells employ less than 60 passes.
Herriott (Herriott, D. R. and Schulte, H. J., "Folded Optical Delay Lines," Appl. Opt., vol. 4, No. 8, pp 883-889 (August 1965)) demonstrated that the use of astigmatic mirrors could greatly increase the spot density, and hence optical path length, in the cell. Each mirror has different finite focal lengths (fx and fy) along orthogonal x and y axes, and the mirrors are aligned with the same focal lengths parallel to one another. The resulting spots of each reflection on the mirrors create precessions of ellipses to form Lissajous patterns. Since these patterns are distributed about the entire face of each mirror, many more spots can be accommodated as compared to a cell with spherical mirrors. Herriott defines the method of creating the astigmatic mirror is to distort a spherical mirror, either in manufacture or in use, by squeezing a spherical mirror in its mount. He states that the amount of astigmatism required is very small and amounts to only a few wavelengths. McManus (McManus, et al., "Astigmatic mirror multipass absorption cells for long-path-length spectroscopy," Appl. Opt., vol. 34, No. 18, pp 3336-3348 (20 Jun. 1995)) outlines the theory and behavior of this astigmatic Herriott cell and shows that the density of passes can be increased by factors of three or more over spherical mirror cells. For these astigmatic mirror cells, light is injected through a hole in the center of the input mirror. Allowed solutions for re-entrant configurations are characterized by a pair of integer indices Mx and My, since there are now two focal lengths present along orthogonal axes.
The drawback of this design is that the constraints to achieve useful operation are very severe. First of all, both Mx and My must simultaneously be re-entrant, so that for a desired N and variable distance d, the focal lengths fx and fy, must be specified to a tolerance of 1 part in 104. Since mirrors can rarely be manufactured to such tolerances, this cell as originally proposed is impractical for routine use. However, Kebabian (U.S. Pat. No. 5,291,265 (1994)) devised a method to make the astigmatic cell usable. Starting with the astigmatic Herriott setup with the same mirror axes aligned, he then rotates one mirror around the z-axis (FIG. 2), thereby mixing the (previously independent) x and y components of the beam co-ordinates. A moderate rotation of ˜5-20 degrees and a small compensating adjustment of the mirror separation distance can accommodate the imprecision in the manufacturing of the mirror focal lengths. However, this approach is still difficult to achieve in practice and requires complex calculations and skill to get to the desired pattern. Furthermore, the astigmatic mirrors must still be custom made and cost many thousands of dollars for a single pair.
Recently, Hao (Hao, L.-Y., et. al., "Cylindrical mirror multipass Lissajous system for laser photoacoustic spectroscopy," Rev. Sci. Instrum., vol. 73, No. 5, pp. 2079-2085 (May 2002)) described another way to generate dense Lissajous patterns using a pair of cylindrical mirrors, each having a different focal length, and where the principal axes of the mirrors are always orthogonal to one another. In essence, this creates a pair of mirrors whose x-axis comprises one curved surface (mirror A) of focal length fx and one flat mirror surface (mirror B), and in the y-axis comprises one flat mirror surface (on mirror A) and one curved surface of focal length fy (mirror B), where fx≠fy. Formulas to predict the spot patterns on each mirror are provided. The advantage to this system is that the dense Lissajous patterns can be formed from a pair of inexpensive mirrors, in contrast to the requirement for custom astigmatic mirrors (we note that for a practical commercial multipass cell, one cannot rely on simply squeezing spherical mirrors to achieve a reliable long term, stable set of focal lengths. Thus diamond turned custom astigmatic mirrors must be made). The drawback of this mismatched focal length pair of cylindrical mirrors is that, similar to the astigmatic Herriott cell, for a given pair of focal lengths, there is only one allowed re-entrant solution value of N permitted. Of course, for photoacoustic measurements as intended by Hao, where any exiting light is not detected, the light does not necessarily have to be re-entrant and many values of mirror separation which are not re-entrant, but do generate many passes, are useful.
The present invention describes a simple, low cost and more easily aligned high density multipass optical cell, where many different paths can be achieved with the same set of mirrors. The key to this invention is the use of cylindrical mirrors with nominally equal focal lengths. When two cylindrical mirrors are aligned such that the curved axes are crossed at 90 degrees (orthogonal condition), they generate spot patterns similar to a spherical Herriott cell, except that the stable resonator conditions restrict the allowed separations to 0<d≦2f. If the entry point of the laser beam is off the central axis, elliptical spot patterns similar to a spherical cell are generated; if the beam enters through the center of one mirror, then lines instead of ellipses form and different re-entry restrictions apply.
The present invention has also determined that, by rotating the cylindrical mirrors to angles δ other than 90 degrees, the previously elliptical or linear spot patterns degenerate into dense Lissajous patterns of spots that generally fill a rectangularly-spaced region of each mirror. Without complex alignment procedures, and starting from a predetermined 90 degree crossed pattern, one can readily generate predicted dense patterns and much longer optical path lengths by twisting either mirror over the unrestricted range of rotation angle δ. This works for both off-axis and central axis input holes and almost any value of N can be achieved within the stability constraints for d and at almost any rotation. Unlike the astigmatic cell or mismatched cylindrical cell, achieving alignment of these spot patterns does not rely on the absolute manufactured focal lengths, but only on the easily adjusted ratio d/f and relative twist angle of the two cylindrical axis planes.


A method of disassembling an image sensor package, which includes a substrate and a glass layer at opposite sides. The method includes the steps of: providing a film tape adhered to the glass layer; providing a vacuuming means to suck the substrate of the image sensor package; and moving the vacuuming means away from the film tape to peel the glass layer off the image sensor package.

1. Field of the Invention
The invention relates to a method of disassembling an image sensor package, and more particularly to a method of disassembling an image sensor package to increase the product reliability and to simplify the disassembling processes.
2. Description of the Related Art
A general sensor is used to sense signals, which may be optical or audio signals. The sensor of the invention is used to receive image signals or optical signals. After receiving the image signals, the sensor converts the image signals into electrical signals, which are then transmitted to a printed circuit board via a substrate.
Referring to FIG. 1, an image sensor structure includes a substrate 10, a frame layer 18, a photosensitive chip 26, a plurality of wires 28, and a transparent layer 34.
The substrate 10 has a first surface 12 on which a plurality of first electrodes 15 are formed, and a second surface 14 on which a plurality of second electrodes 16 are formed. The first electrodes 15 are respectively electrically connected to the second electrodes 16 by the conductive wires 17, which are located at the side of the substrate. The frame layer 18 has an upper surface 20 and a lower surface 22 adhered to the first surface 12 of the substrate 10 to form a chamber 24 together with the substrate 10. The photosensitive chip 26 is arranged within the chamber 24, and is mounted to the first surface 12 of the substrate 10. Each wire 28 has a first terminal 30 and a second terminal 32. The first terminals 30 are electrically connected to the photosensitive chip 26, and the second terminals 32 are electrically connected to the first electrodes 15 of the substrate 10. The transparent layer 34 is adhered to the upper surface 20 of the frame layer 18.
The image sensor package typically has to be tested to check whether the number of particles left in the image sensor package satisfies the quality standard. However, when the test result represents that the number of particles exceeds the quality standard, the transparent layer 34 cannot be removed and cleaned. Instead, the overall image sensor package has to be treated as waste material. Thus, the material is wasted and the manufacturing cost is high.

Method of disassembling an image sensor package


A domain controller hierarchy includes one or more hub domain controllers in communication with one or more local domain controllers, such as local domain controllers at a branch office. The hub domain controller(s) is writable, while the local domain controller(s) is typically read-only. Non-secure and secure information is partitioned to specific local domain controllers at the one or more hub domain controllers. The non-secure and secure information is then passed from the hub domain controller only to the local domain controller associated with the given partition at the hub domain controller on request. For example, a user requests a logon at a client computer system at a local branch office, and the logon is passed from the local domain controller to the hub domain controller. If authenticated, the user logon account is passed to the local domain controller, where it can be cached to authenticate subsequent requests.

As computerized systems have increased in popularity, so have the needs to distribute files and processing resources of computer systems in networks both large and small. In general, computer systems and related devices communicate information over a network for a variety of reasons, for example, to exchange personal electronic messages, sell merchandise, provide account information, and so forth. One will appreciate, however, that as computer systems and their related applications have become increasingly more sophisticated, the challenges associated with sharing data and resources on a network have also increased.
Generally, there are a number of different mechanisms and protocols for distributing resources among computer systems. For example, two or more computers in a corporate network can share resources, such as files, application programs, or the like, over, for example, a Local Area Network ("LAN"), or a Wide Area Network ("WAN"). The computers can share these resources using any number of currently available transmit and receive communication protocols established between them.
More complicated schematics for sharing resources on a network include, for example, a domain controller hierarchy scheme, which is used in some implementations to organize and share both secure and non-secure resources in an efficient manner. For example, a central hub domain controller might be used to manage user names, passwords, computer names, network identifiers, or the like, and provide the information through a hierarchy of remote and local servers (i.e., local domain controllers). The various domain controllers, in turn, are configured with a Security Account Manager ("SAM"), which provides interfaces and storage for holding or passing along security information within the domain hierarchy. When one or more individual client computer systems requests a resource, the request may be passed along the hierarchy before the user receives a response.
In one example, a large pharmaceutical company that has several local branch offices (e.g., neighborhood pharmacies), might want to establish a local domain controller at each of the different local pharmacies. The company might do so by establishing a domain controller at each branch office. Each different branch office might therefore be part of a sub-domain in the hierarchy, or might even represent its own individual sub-domain of yet another sub-domain in the company's domain hierarchy. The established domain controller is typically configured for, among other things, operating in accordance with resource guidelines pushed downward from the centralized hub domain controller.
In this example, the hub domain controller will be "writable or configured to be written-to by an administrator in the main organization for the branch domain. By contrast, the local domain controllers to which the central writable domain controller connect in the branch domain, however, will be "read-only", and not therefore configured to be written-to in any meaningful way by the local users, or sometimes even the network administrator. In such an example, each local domain controller would be configured primarily, for example, to pass along user requests, such as a logon request, to the writable hub domain controller, and then pass along the relevant account approval information sent back from the hub domain controller. For example, a user logs onto a client machine, and the local domain controller forwards the request to the hub domain controller for authentication. If the hub domain controller verifies the user's entered information, the hub domain controller instructs the local domain controller to allow the user to logon to the client computer system.
While this example schematic might have an advantage of being highly centralized, it also has a number of different difficulties, such as a low degree of local configurability (or none at all) for the various local domain controllers. For example, in order for a user to change a password (or reconfigure another resource), the user will usually need to contact an administrator managing the hub domain controller, who will then change the password (or resource) at the hub domain controller before the user can use the new password (or resource) at the local branch. Furthermore, although minimizing the amount of technical support staff needed at the local branch, this centralized domain controller schematic represents a single point of failure throughout the entire company's network. For example, when the hub domain controller is unavailable for any reason, users at the local branch might be unable to access a certain resource (e.g., logon to their respective client computer systems), since the local domain controller will not store the given information necessary to validate the client's request.
Alternative implementations to the foregoing examples include local and hub domain controllers that are each writable. Under this type of schematic, the hub domain controller sends not just resource configuration information, but also security account information for the company or organization, such that each local domain controller stores all security accounts for the company. Thus, when any user of the company logs onto any client machine at any local branch, the local domain controller, rather than the hub domain controller, authenticates the user's credentials, and provides client computer system access. Since resources such as these are stored locally, the user may also be able to configure other resources at the local domain controller, such as the share-ability of a certain file, or access to another file system, or the like. Furthermore, an appropriately authorized user, can also change or update certain security account (or other configuration) information at the local domain controller, as opposed to changing this information by dealing with the network administrator of the hub domain controller. Changes at the user's local domain controller are then propagated throughout the other local and remote domain controllers in the hierarchy.
While this writable local and remote domain controller schematic has an advantage of decentralizing domain controller configurability and access, this schematic can also present other potential problems, such as security issues, when used in local branch offices that do not have trained technical support staff. For example, there is a heightened risk that one of the local users at a local branch might inadvertently modify a resource at the local domain controller that should not be modified. This is possible in part since many resources in present operating systems now come with a high degree of configuration granularity, which is difficult, if not impossible, for many non-technical branch users to successfully navigate. If there is no local technical support when a configuration mistake is made, the local branch might have to wait until a trained network administrator can fix the problem on-site, or fix it over the company's network as available.
One can appreciate that the writable local and remote domain controller schematic also presents a variety of exposure concerns. For example, the local domain controllers in the prior example may be accessible by other local domain controllers on the company network, and sometimes also by others on an outside, non-corporate network (e.g., Internet). Furthermore, the writable local domain controllers can present heightened security risks due to physical intrusion concerns, since, as a practical matter, organizations tend not to place the local domain controllers in physical secure locations. That is, the organization may want the benefits of a writable local domain controller, but not want to expend the resources to guard against virtual and physical security risks. Such physical risks can include removal or replacement of server hardware (e.g., hard drives, and the like).
As such, a number of difficulties can be found both with schematics with one writable domain controller and those with all domain controllers being writable, particular when implemented in branch locations that are separated from a head office location.

Replicating selected secrets to local domain controllers


A drive circuit includes a bias current supply circuit for supplying a bias current to a light-emitting element and a modulated current supply circuit for supplying a modulated current to the light-emitting element, and has a first path through which the bias current flows, a second path including a path for supplying the modulated current to the light-emitting element from the modulated current supply circuit, through which a current returns to the bias current supply circuit through the modulated current supply circuit from the bias current supply circuit without going through the light-emitting element when the bias current flows, and a third path which is joined to the second path in the modulated current supply circuit and has an adjusting resistance before a junction, through which a current flows through the adjusting resistance to the bias current supply circuit when the bias current flows.

The Internet has widely been used in recent years and users can access various types of information on sites operated all over the world and can obtain such information. Use of devices adapted to broadband access such as asymmetric digital subscriber line (ADSL) and fiber to the home (FTTH) has also rapidly spread accordingly.
IEEE Std 802.3ah™-2004 (NPD 1) discloses one scheme for a passive optical network (PON), which is medium-sharing-type communication in which a plurality of optical network units (ONUs) share an optical communication line and transmit data with an optical line terminal (OLT). Namely, NPD 1 defines Ethernet® PON (EPON), under which all information including user information passing through a PON and control information for administering and operating a PON is communicated in a form of an Ethernet® frame as well as an access control protocol (multi-point control protocol (MPCP)) and an operations, administration and maintenance (OAM) protocol for EPON. By exchanging MPCP frames between an optical line terminal and an optical network unit, joining, leaving, upstream multiple access control, or the like of an optical network unit is carried out. NPD 1 describes a method of registering a new optical network unit, a report showing a request for allocation of a band, and a gate indicating a transmission instruction based on an MPCP message.
In 10G-EPON standardized as IEEE802.3av™-2009 as well, that is, EPON in which a communication rate is adapted to 10 gigabits/second, which represents a next-generation technique for gigabit Ethernet® passive optical network (GE-PON) realizing a communication rate of 1 gigabit/second, an access control protocol is premised on the MPCP.
Japanese Patent Laying-Open No. 2010-267924 (PTD 1) discloses a laser drive circuit included in a transmitter in optical communication. The laser drive circuit includes a modulation circuit which supplies a modulated current to a laser diode in accordance with input burst data and a bias circuit which provides a bias current to the laser diode. The modulation circuit includes a differential drive circuit, and the differential drive circuit and the laser diode are AC coupled to each other by a capacitive element. In the differential drive circuit, a terminal resistance for impedance matching is connected between a pair of transistors and a power supply line.