A branch circuit is formed by forming an optical filter by means of connecting a wavelength selective reflector to between two units of directional coupler and further assembling three units of the optical filter. In the branch circuit, the three optical filters are connected to each other so that the light coming in from a first optical filter is outputted to a third optical filter when the wave length selective reflector reflects the light, and to a second optical filter when the wavelength selective reflector passes the light therethrough; the light coming in from the second optical filter is outputted to the first optical filter when the wavelength selective reflector reflects the light, and to the third filter when the wavelength selective reflector passes the light therethrough; and also the light coming in from the third optical filter is outputted to the second optical filter when the wavelength selective reflector reflects the light and to the first optical filter when the wavelength selective reflector passes the light therethrough.

In association with rapid expansion of needs for optical communications, substantial increase in a transfer capacity has been required. So far increase of transfer capacity has been realized with increase in a processing speed according to a synchronous digital hierarchy (SDH), namely with introduction of time division multiplexing (TDM). Today the maximum value in the practical transfer rate is 10 Gbit/s. This is a limit speed processable in an electronic circuit for commercial use, which causes increase in costs for a transfer path terminal device.
On the other hand, in association with progress in the laser diode (LD) manufacturing technology as well as with smoothing of a gain for an erbium dope optical fiber amplifier (EDFA), a wavelength division multiplexing system has been gathering intense attentions from related people. In this system, light signals having different wavelengths are used as carrier waves, a transfer speed for one wave is suppressed at a low level, and existing types of transfer path terminal devices can be used, which makes it possible to suppress costs for the entire system.
Also if each station device is formed with light receiving circuit parts, all station devices are connected with an optically transparent medium not including a process for conversion between electricity and light. Conventionally switching of a transfer path is executed by means of converting light to electricity or converting electricity to light and also by terminating a signal to read path information and electrically switching path connection, but if the WDM technology is used, it is possible to easily switch a transfer path not by means of converting light to electricity, nor by converting electricity to light. This allows simplification of maintenance and administration management of a network.
As a wavelength multiplexed light communication device required in various types of network using the WDM technology, it is possible to enumerate (1) a light branch circuit used in a bus type of network, (2) an add/drop multiplexing circuit used in a ring-type network, and (3) a bidirectional wavelength multiplexing/separating circuit used in a star-type network.
In the submarine cable system, an optical branch circuit for branching an optical cable running in one direction to two branches running in different directions respectively has been required. So far an optical branch circuit having a two-conductor optical cable for each destination has been used, but in this case totally four conductors, two for an up-link channel and remaining two for a down-link channel, have been required, which causes increase in weight of an optical cable as well as in costs thereof. In contrast, by using the WDM technology, a number of required conductors can be reduced to a half, as described in "Optical Submarine Cable Communication" supervised by Noboru Oyama, Moriji Kuwabara, KEC, pp.141-151, 1991.
FIG. 28 shows an example of an optical branch circuit using the WDM technology. In this figure, designated at the reference numeral 300 is an optical branch circuit, at 301a, 301b, and 301c are optical filters each for dividing a wavelength, at 302a, 302b, and 302c are optical filters each for synthesizing a wavelength. For instance, light waves having a wavelength of .lambda.1 and .lambda.2 introduced from the cable A are separated from each other by the optical filter 301a, and the light wave having a wavelength of .lambda.1 goes through the optical filter 302c into the cable C and the light wave having a wavelength of .lambda.2 goes through the optical filter 302b into the cable B. On the other hand, light waves having a wavelength of .lambda.1 and .lambda.2 respectively introduced from the cable B are separated from each other by the optical filter 301b, and the light wave having a wavelength of .lambda.1 goes through the optical filter 302a into the cable A, while the light wave having a wavelength of .lambda.2 goes through the optical filter 302c into the cable C. Thus, by using two different wavelengths, branching of an optical cable to two directions becomes possible.
By the way, in the optical filters 301a, 301b, 301c, 302a, 302b, and 302c each playing an important role in this optical branch circuit, the dielectric multilayered film filter as shown in FIG. 29 has been used in most cases.
Next, a description is made for operations of the dielectric multilayered film filter with reference to FIG. 29. In this figure WDM light coming in from a terminal 290 is collimated by a lens 291a and reaches the dielectric multilayered film 292. This dielectric multilayered film 292 is designed so that it reflects, for instance, a light wave having a wavelength of and passes light waves having other wavelengths. The reflected light wave having a wavelength of .lambda.1 is focused by the lens 291b and sent to a terminal 290b. A light receiver 294 is connected to this point. On the other hand, a light transmitter 293 for a light wave having a wavelength of .lambda.5 is connected to a terminal 290c, the light wave passes through the lens 291c, dielectric multilayered film 292 and is outputted to the terminal 290a.
As a concrete example of the ring type of network, there is, for instance, the add/drop mutiplexer (ADM) network based on the WSM technology described in "M. J.Chawki, V. Tholey, E. Delevaque, S. Boj and E. Gay, `Wavelength reuse scheme in a WDM unidirectional ring network using a proper fiber grating add/drop multiplexer`, Electronics Letters, vol. 31, No.6, pp. 476-477, 1995". The ADM indicates a multiplexer which drops a signal to a station and at the same time add a signal transmitted from the station to other station.
A network connected with a ring type of optical fiber is connected through an optical cross-connect device to other network. For instance, a light wave having a specific wavelength of .lambda.1 is allocated to a station 1. Of the WDM signals arriving in the station 1, only a light wave having a wavelength of .lambda.1 transmitted to the station is branched by an optical filter and is received by a light receiver. On the other hand, a signal transmitted from a light transmitter in the station 1 is added to the optical fiber using a light wave having a wavelength of .lambda.1 as a carrier wave. To which station each light wave has been transmitted can be recognized by checking a wavelength of each light wave. Similarly a light wave having a specific wavelength of .lambda.2 is allocated to a station 2.
FIG. 30 shows an example of a wavelength multiplexed light transfer device according to the conventional technology which has been proposed as an optical filter required for a ring type of network. The basic principle of this type of optical filter was described in "K. 0. Hill, D. C. Johnson, F. Bilodeau, S. Faucher, 1 Narrow-bandwidth optical waveguide transmission filters`, Electronics Letters vol. 23, No.9, pp.465-466, 1987", and then was described more detailedly in "D. C. Johnson, K. O. Hill, F.Bilodeau, S. Faucher, `New design concept for a narrow band wavelength-selective optical tap and combiner` Electronics Letters vol. 23, No.13, pp.668-669, 1987". The same contents is also described in U.S. Pat. No.4,900,119. A similar invention is described in Japanese Patent Laid-Open Publication No. 96605/1989.
In FIG. 30, designated at the reference numerals 310a, 310b is a fiber grating, at 311a and 311b is a 2.times.2 3-dB coupler, at 312 a light transmitter, and at 313 a light receiver. Also designated at the reference numerals 314a, 314b is a refractive index adjusting section, at 315a, 315b a terminal in the front stage of the 3-dB coupler 311a, at 315c, 315d a terminal in the rear stage of the 3-dB coupler 311a, at 316a, 316b a terminal in the front stage of the 3-dB coupler 311b, and at 316c, 316d a terminal in the rear stage of the 3-dB coupler 311b.
The fiber grating was invented by K. O. Hill et al. working in Communication Research Center in Canada, and when an optical fiber is exposed to an ultraviolet ray from outside, a lattice defect is caused and cyclic fluctuation of a refractive index occurs, so that a fiber grating works as a wavelength selective reflector. The fiber grating is characterized in that the wavelength reproducibility is high and the insertion loss is extremely low.
Assuming that a grating pitch of the fiber grating is .LAMBDA., an equivalent refractive index of the fiber is neff, an effective grating length is Leff, and a coupling coefficient is .kappa., a central wavelength .lambda.B of the Bragg's reflection is equal to .LAMBDA./neff (.lambda.B=.LAMBDA./neff), while a reflection coefficient R at a central wavelength of the reflected light is equal to tanh 2 (.kappa.Leff).
For convenience of description, it is assumed herein that a Bragg's wavelength (a wavelength of a reflected light wave) for the fiber gratings 310a, 310b in this example of the conventional technology has been set to .lambda.5. The fiber grating itself works only as a wavelength selective reflector, but when the 3-dB coupler 311a is connected to a front stage thereof, of the WDM light waves coming in from the terminal 315a, only the light wave having a wavelength of .lambda.5 is reflected by the fiber grating, and can be taken out from the terminal 315b of the 3dB coupler.
The light coming in from the terminal 315a is divided to two portions, which are sent to the terminals 315c, 315d respectively. The light waves coming out from the terminals 315c, 315d are reflected by the fiber gratings 310a, 310b respectively and return to the 3-dB coupler 311a again, but when returning from the terminal 315a to the terminal 315a, a light wave flowing through the first route comprising the terminal 315a, terminal 315c, fiber grating 310a (reflection), terminal 315c, and terminal 315a in this order is synthesized with a light wave flowing through a second route comprising the terminal 315a, terminal 315d, fiber grating 310b (reflection), terminal 315d, and terminal 315a in this order, and the synthesized light wave goes out from the terminal 315a, but a phase difference of .pi./2 between a light wave passing through the coupler and the coupled light wave is generated in the 3-dB coupler, so that a phase difference of .pi. is generated between the transmitted light waves passing through the light paths from the terminal 315a to the terminal 315c and from the terminal 315c to the terminal 315a in the first route and between the coupled light waves passing through the light paths from the terminal 315a to the terminal 315d and from the terminal 315d to the terminal 315a in the second route, and a phase of the light in the first route is reverse to that of the light in the second route, so that interference between the light waves is canceled.
When returning from the terminal 315a to the terminal 315b, a light wave flowing through a first route comprising the terminal 315a, terminal 315c, fiber grating 310a (reflection), terminal 315c, and terminal 315b in this order is synthesized with a light wave flowing in a second route comprising the terminal 315a, terminal 315d, fiber grating 310b (reflection) terminal 315d, and terminal 315b, and the synthesized light wave goes out from the terminal 315b, but a light wave running from the terminal 315a to the terminal 315c in the first route is a transmitted light wave and a light wave running from the terminal 315c to the terminal 315b in the first route is a coupled light wave, while in the second route a light wave running from the terminal 315a to the terminal 315d is a coupled light wave and that running from the terminal 315d to the terminal 315b is a transmitted light, and thus a phase delay of .pi./2 is generated in both the light waves running in the first and second routes, meaning that the total phase delay is .pi., and an interference between the light waves is intensified. For this reason, the light wave having a wavelength .lambda.5 from the terminal 315a is sent to the terminal 315b.
Light waves each having a wavelength other than .lambda.5 and not reflected by the fiber grating reach the 3-dB coupler 311b, but when sent from the terminal 315a to the terminal 316c, a light wave running through the first route comprising the terminal 315a, terminal 315c, fiber grating 310a (transmission), terminal 316a and terminal 316c in this order is synthesized with a light wave running through the second route comprising the terminal 315a, terminal 315d, fiber grating 310b (transmission), terminal 316b, and terminal 316c, and the synthesized light wave goes out of the terminal 316c, but a light wave passing through the light paths from the terminal 315a to the terminal 315c and from the terminal 316a to the terminal 316c in the first route is a transmitted light wave, while the light wave passing through the light paths from the terminal 315a to the terminal 315d and from the terminal 316b to the terminal 316c in the second route is a coupled light wave, so that a phase difference of .pi. is generated, and a phase of the light wave running through the first route is reverse to that of the light wave running through the second route, so that interference between the light waves is canceled.
When sent from the terminal 315a to the terminal 316d, a light wave running through a first route comprising the terminal 315a, terminal 315c, fiber grating 310a (transmission), terminal 316a, and terminal 316d is synthesized with a light wave running through a second route comprising the terminal 315a, terminal 315d, fiber grating 310b (transmission), terminal 316b, and terminal 316d, and the synthesized light wave goes out of the terminal 316d, but in the first route a light wave passing through the light path from the terminal 315a to the terminal 315c is a transmitted light wave and a light wave passing through the light path from the terminal 316a to the terminal 316d is a coupled light wave, while in the second route a light wave passing through the light path from the terminal 315a to the terminal 315d is a coupled light wave and that passing through the light path from the terminal 316a to the terminal 316d is a transmitted light wave, so that a common mode by a phase delay of .pi./2 is generated between the light wave running through the first route and that running through the second route, and the light waves is intensified by this interference. For this reason, light waves each coming in from the terminal 315a and having a wavelength other than .pi.5 is sent to the terminal 316d.
On the other hand, a signal having a wavelength of .pi.5 to be inserted is transmitted from the light transmitter 312 connected to the terminal 316c and is set to the terminal 316d. The operations are the same as those in a case when a light wave coming in from the terminal 315a and having a wavelength of .lambda.5 is sent to the terminal 315b. For this reason, a light wave coming in from the terminal 315a and having a wavelength other than .lambda.5 is sent to the terminal 316d.
It should be noted that the refractive index adjusting section 314a adjusts a refractive index so that a length of each light path from the 3-dB coupler 311a to each of the fiber gratings 310a, 310b will be identical. Also the refractive index adjusting section 314b adjusts a refractive index so that a length of each light path from the 3-dB coupler 311b to each of the fiber gratings 310a, 310b will be identical.
The refractive index adjusting sections 314a, 314b can adjust a refractive index by means of exposure to a ultraviolet ray like in the method of manufacturing a fiber grating. This technology is described in Japanese Patent Laid-Open No. 298702/1992.
Concrete examples of the star-shaped network include the LAMBDANET. Detailed description thereof is provided in "M. S. Goodman, H. Kobrinski, M. P. Vecchi, R. M. Bulley, and J. L. Gimlett, IEEE Journal of Selected Areas in Communications, vol. 8, p.995, 1990". A light transmitter for a light wave having an allocated wavelength is provided in each station. A light signal going out of the light transmitter passes through a star coupler and reaches all the stations. Each station selects a light wave having a desired wavelength from all light waves received by the station. For instance, a specific wavelength .lambda.1 is allocated to a light transmitter provided in the station 1. On the other hand, in a case where a wavelength of signal for a light receiver in the station 1 to receive is .lambda.5 which is a wavelength specific to a signal transmitted by a light transmitter provided in a station 5, the light receiver selectively receives the signal having the wavelength. A function required to an optical filter is bidirectional wavelength multiplexing for light waves having wavelengths of .lambda.1 and .lambda.5. Conventionally a dielectric multilayered film filter has been used for this optical filter.
Configuration of an optical filter based on the conventional technology was as described above. Several problems in the conventional type of optical filter have degraded operations and characteristics of the system and also complicated the configuration.
One of the problems relating to the example of the conventional technology 1 is that a dielectric multilayered film filter has a large passage loss and many optical parts are used, which makes it difficult to assemble the optical filter. Furthermore an optical signal once goes out of an optical fiber into a space, passes through a lens or a dielectric multilayered film, and then goes into an optical fiber again, so that displacement of the light axis easily occurs, and if displacement of the light axis should occur, a severe accident such as breakage of an optical cable which is a trunk line may easily occur.
One of the problems relating to the example of the conventional technology 2 occurs in a ring type of network in a case where two or more light waves having different wavelengths are allocated to a station with increased line demands. However, two light waves having different wavelengths can not be dropped nor added by the optical filter shown in FIG. 30 simultaneously.
In the optical filter shown in FIG. 30, it is extremely difficult to achieve the refractive index of 100% for the fiber gratings 310a and 310b. When a coupling parameter .kappa.L is 2, R is 93%. In this step, of the light waves each sent from the light transmitter 312 and having a wavelength of .kappa.5 (called an adding light), those not reflected and passing therethrough, equivalent to 7% of all the light waves, may go into the light receiver 313 (This light is called crosstalk light). The light receiver 313 receives a light wave coming in from the terminal 315a and having a wavelength of .lambda.5 (this light is called dropping light). Namely an adding light from the transmitter 312 may cause crosstalk with a dropping light to be received by the receiver 313, which disadvantageously degrades the receiving characteristics.
In FIG. 30, if there are no fiber gratings 310a, 310b, of the power Pa of the adding light coming in from the terminal 316c, a ratio of a power added to the terminal 315b vs a power outputted to the terminal 315a is defined as isolation .eta..
Namely: EQU .eta.=(Power outputted to the terminal 315a)/(Power outputted to the terminal 315b) (1)
In a case where the refractive index adjusting sections 314a and 314b can be manufactured so that a length of a light path in the 3-dB coupler 311a is completely identical to that of the 3-dB coupler 311b, .eta. is zero (0), but in the manufacturing technology currently available, .eta. can be suppressed at most to a range from 0.1 to 0.01. Herein, in a case where an excessive loss in all light paths is ignored, power of the adding light coming in from the terminal 316c and going into the terminal 315b is expressed by the expression of Pa (1-R) / (1-.eta.). On the other hand, of power Pd of a light wave coming in from the terminal 315a, power of a dropping light outputted to the terminal 315b is expressed by the expression of Pd / (1-.eta.)Then, a ratio of crosstalk light vs. dropping light, namely the crosstalk X is given by the following expression: EQU X=Pa (1-R) / (Pd) (2)
When R is 93% and Pa is equal to Pd, X is 0.07 (=-11.6 dB).
The power penalty PP when crosstalk occurs in a state where a difference .DELTA. between an optical frequency of an adding light and that of a dropping light is zero (0) and polarization of the former is identical to that of the latter is expressed by the following expression: EQU PP=-10 log (1-4.multidot..sqroot.X) (3)
Namely, when X is 0.02, a power penalty of up to 3.6 dB is generated.
FIG. 31 shows a result of an experiment carried out using a 10 Gbit/s light transfer device to know a power penalty against crosstalk X. In this figure, a black circle indicates a value obtained by the experiment and a solid line indicates a value by computing according to the expression (1) . A result of the experiment well coincided with the computed value, and it was confirmed that a power penalty of 1 dB is generated against crosstalk of only -25 dB. To suppress a power penalty to, for instance, 0.2 dB or less, the crosstalk must be suppressed under -39 dB. The refractive index R to satisfy the requirement is computed as 99.99% from the expression (2). When viewed from a viewpoint of actual conditions in production of fiber gratings, it is extremely difficult to satisfy this requirement.
In a ring type of network, sometime it is required to switch a wavelength of dropped and adding light wave to a given wavelength in association with fluctuation in demands for each line. However, in the optical filter shown in FIG. 30, it is impossible to freely select a wavelength.
An optical filter required for a star-shaped network can be formed with the dielectric multilayered film as shown in FIG. 29, a section between an input fiber and an output fiber in the dielectric multilayered film optical filter is formed with a lens system, so that not only the insertion loss is large, but also the assembly is difficult, which is disadvantageous for mass production thereof.
A first object of the present invention is to provide an optical branch circuit in which a passage loss due to wavelength multiplexing is small and displacement of light axis never occurs.
A second object of the present invention is to insure a communication path for communication between terminal stations with each other by increasing terminal stations each accommodated in a wavelength multiplexed optical transfer system and separating a troubled portion therefrom even if any trouble occurs in the transfer path.
A third object of the present invention is to provide a construction in which a passage loss due to wavelength multiplexing is small and a number of wavelengths for a specified path can be obtained as many as possible in the optical branch circuit in which displacement of light axis never occurs.
A fourth object of the present invention is to provide an optical dropping/adding circuit which can communicate with any other station.
A fifth object of the present invention is to provide an optical filter which can multiplex a plurality of light waves by dropping and adding them.
A sixth object of the present invention is to provide an optical filter which can suppress a frequency of crosstalk and of which the transfer characteristics is not degraded even in a case where a wavelength of a dropping light wave is the same as that of an adding light wave.
A seventh object of the present invention is to provide an optical filter which can select a wavelength to be dropped and added for multiplexing.
An eighth object of the present invention is to provide an optical filter in which a loss is small when bidirectional WDM is executed, and also which can easily be assembled and is suited to mass production.
A wavelength multiplexed light transfer unit according to the present invention comprises first, second, and third optical filters each having a first terminal into which a light signal having a specified wavelength .lambda.1 and a light signal having a wavelength other than .lambda.1 are inputted; a second terminal which outputs the light signal having a wavelength .lambda.1 inputted into this first terminal; a third terminal into which the light signal having a wavelength other than .lambda.1 is inputted; and a fourth terminal which outputs the light signal having a wavelength other than .lambda.1 inputted to the first terminal, and also each outputting the light signal having a wavelength other than .lambda.1 inputted into the third terminal to the second terminal; in which the third terminal of the first optical filter and the fourth terminal of the second optical filter are connected to each other; the third terminal of the second optical filter and the fourth terminal of the third optical filter are connected to each other; and the third terminal of the third optical filter and the fourth terminal of the first optical filter are connected to each other.
In a wavelength multiplexed light transfer system according to the present invention, terminal station equipments each having a light transmitting/receiving device for transmitting or receiving a light signal having a specified wavelength .lambda.1 and that having a wavelength other than .lambda.1 through the wavelength multiplexed light transfer unit vertically connected to each other are communicated with each other.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first filter having a first terminal into which a light signal having a specified wavelength .lambda.1 and a light signal having a wavelength other than .lambda.1 are inputted; a second terminal which outputs the light signal having a wavelength of .lambda.1 inputted into this first terminal; a third terminal into which the light signal having a wavelength other than .lambda.2 is inputted; and a fourth terminal which outputs the light signal having a wavelength other than .lambda.1 inputted to the first terminal; and second and third filters each having: a first terminal into which a light signal having a specified wavelength .lambda.2 and a light signal having a wavelength other than .lambda.2 are inputted; a second terminal which outputs the light signal having a wavelength of .lambda.2 inputted into this first terminal; a third terminal into which the light signal having a wavelength other than .lambda.2 is inputted; and a fourth terminal which outputs the light signal having a wavelength other than .lambda.2 inputted to the first terminal; in which the third terminal of the first optical filter and the fourth terminal of the second optical filter are connected to each other; the third terminal of the second optical filter and the fourth terminal of the third optical filter are connected to each other; and the third terminal of the third optical filter and the second terminal of the first optical filter are connected to each other.
A wavelength multiplexed light transfer unit according to the present invention comprises, an optical filter having a first terminal for receiving and inputting a light wavelength multiplexed signal having a wavelength within a specified wavelength band .lambda.B1 allocated to a station for receiving as well as a light wavelength multiplexed signal having a wavelength outside the specified wavelength band .lambda.B1, a second terminal for outputting the light wavelength multiplexed signal having a wavelength within the wavelength band .lambda.B1 inputted into the first terminal, and a third terminal the light wavelength multiplexed signal having a wavelength outside the wavelength band .lambda.B1 inputted into the first terminal; a light receiver into which the light wavelength multiplexed signal outputted to the second terminal of the optical filter is inputted; a light transmitter for outputting a light wavelength multiplexed signal having a wavelength for transmission within a wavelength band allocated from the station to a receiving station; and a directional coupler for synthesizing the light wavelength multiplexed signal having a wavelength outside the wavelength band .lambda.B1 outputted from the third terminal of the optical filter and the light wavelength multiplexed signal outputted from the light transmitter and outputting the synthesized signal for transmission.
A wavelength multiplexed light transfer unit according to the present invention comprises, an optical filter having a first terminal for receiving a light wavelength multiplexed signal having a wavelength within any of N pieces of wavelength band from .lambda.B1 to .lambda.BN as well as a light wavelength multiplexed signal having a wavelength outside the wavelength bands, a second terminal for outputting a light wavelength multiplexed signal having a wavelength within wavelength bands from .lambda.B1 to .lambda.BN inputted into this first terminal, a third terminal for inputting light wavelength multiplexed signal having a wavelength within the wavelength bands from .lambda.B1 to .lambda.BN, and a fourth terminal for outputting the light wavelength multiplexed signal having a wavelength outside the wavelength bands inputted into the first terminal as well as the light wavelength multiplexed signal having a wavelength within the wavelength bands from .lambda.B1 to .lambda.BN inputted into the third terminal; a light receiver for receiving the light wavelength multiplexed signal outputted to the second terminal of the optical filter; and a light transmitter for outputting the light wavelength multiplexed signal having a wavelength within the wavelength bands from .lambda.B1 to .lambda.BN inputted to the third terminal of the optical filter.
A wavelength multiplexed light transfer unit according to the present invention comprises a grating light guide path having a plurality of reflected wavelength formed in the identical grating light guide path as an optical filter.
A wavelength multiplexed light transfer unit according to the present invention comprises, an optical filter having a first terminal for receiving a light signal having a wavelength within a specified wavelength band .lambda.B1 as well as a light signal having a wavelength outside the wavelength band .lambda.B1, a second terminal for outputting the transmitted light signal having a wavelength within the wavelength band .lambda.B1 inputted into this first terminal, a third terminal for receiving a light signal having a wavelength within the wavelength band .lambda.B1, and a fourth terminal for outputting the light signal having a wavelength outside the wavelength band .lambda.B1 inputted into the first terminal as well as the light signal having a wavelength within the wavelength band .lambda.B1 inputted into the third terminal; a light receiver for receiving a light signal outputted to the second terminal of the optical filter; a light transmitter for outputting a light signal to the third terminal of the optical filter; and a light frequency control means for controlling the light transmitter so that the light transmitter will oscillate a light having a wavelength displaced by a specified value from a wavelength of a light signal received by the light receiver.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first optical filter having a first terminal for receiving a light signal having a specified wavelength .lambda.1 as well as a light signal having a wavelength other than the wavelength .lambda.1, a second terminal for outputting the light signal having a wavelength .lambda.1 inputted into this first terminal, a third terminal for outputting a light signal having a wavelength other than the wavelength .lambda.1 inputted into the first terminal; a second optical filter having a fourth terminal for receiving the light signal having a wavelength other than the wavelength .lambda.1 outputted from the third terminal of this first optical filter, a fifth terminal for receiving the light signal having the specified wavelength .lambda.1 as well as that having a wavelength other than the wavelength .lambda.1, and a sixth terminal for outputting the light signal having a wavelength other than the wavelength .lambda.1 inputted into the fourth terminal as well as a transmitted light signal having a wavelength .lambda.1 inputted into the fifth terminal; a light receiver for receiving a light signal outputted to the second terminal of the first optical filter; and a light transmitter for outputting a light signal to the fifth terminal of the second optical filter.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first optical filter having a first terminal for receiving a light signal having a specified wavelength .lambda.1 as well as a light signal having a wavelength other than the wavelength .lambda.1, a second terminal for outputting the light signal having a wavelength .lambda.1 inputted into this first terminal, a third terminal for outputting a light signal having a wavelength other than the wavelength .lambda.1 inputted into the first terminal; and a second optical filter having a fourth terminal for receiving the light signal having a wavelength other than the wavelength .lambda.1 outputted from the third terminal of this first optical filter, a fifth terminal for receiving the light signal having the specified wavelength .lambda.1 as well as that having a wavelength other than the wavelength .lambda.1, and a sixth terminal for outputting the light signal having a wavelength other than the wavelength .lambda.1 inputted into the fourth terminal as well as a transmitted light signal having a wavelength .lambda.1 inputted into the fifth terminal; in which the third terminal of the first optical filter and the fourth terminal of the second filter are connected to each other with a wavelength selective reflector in which a center wavelength of reflection is .lambda.I.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first optical filter having a first terminal for receiving a light signal having a specified wavelength .lambda.2 as well as a light signal having a wavelength other than the wavelength .lambda.2, a second terminal for outputting the light signal having a wavelength .lambda.2 inputted into this first terminal, a third terminal for outputting a light signal having a wavelength other than the wavelength .lambda.2 inputted into the first terminal; a second optical filter having a fourth terminal for receiving the light signal having a wavelength other than the wavelength .lambda.2 outputted from the third terminal of this first optical filter, a fifth terminal for receiving the light signal having the specified wavelength .lambda.2, and a sixth terminal for outputting the light signal having a wavelength other than the wavelength .lambda.2 inputted into the fourth terminal as well as a transmitted light signal having a wavelength .lambda.2 inputted into the fifth terminal, a third optical filter having a seventh terminal for receiving a light signal having a specified wavelength .lambda.1 as well as a light signal having a wavelength other than the wavelength .lambda.1, an eighth terminal for outputting the light signal having a specified wavelength .lambda.2 as well as a light signal having a wavelength .lambda.1 inputted into the seventh terminal, a ninth terminal for receiving a light signal having a wavelength .lambda.2 outputted to the eighth terminal, and a tenth terminal for outputting a light signal having a wavelength other than the wavelength .lambda.1 received from the seventh terminal; and a fourth optical filter having a twelfth terminal for receiving the light signal having a wavelength other than the wavelength .lambda.1 outputted from the tenth terminal of the third optical filter, a thirteenth terminal for receiving the light signal having the specified wavelength .lambda.1 as well as the light signal having a specified wavelength .lambda.2, a fourteenth terminal for outputting the light signal having a wavelength .lambda.1 received from the thirteenth terminal as well as a light signal having a wavelength other than the wavelength .lambda.1 received from the twelfth terminal, and an eleventh terminal for outputting the light signal having a wavelength .lambda.2 received from the thirteenth terminal; in which the second terminal and the ninth terminal are connected to each other, and the fifth terminal and the eleventh terminal are connected to each other.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first light circulator having a first port for receiving N waves of light wavelength multiplexed signal having specified wavelengths from .lambda.1 to .lambda.N, a second port for outputting the light wavelength multiplexed signal inputted into the first port, and a third port for outputting the light wavelength multiplexed signal inputted into the second port; a directional coupler having a first terminal for receiving a light wavelength multiplexed signal having a wavelength within any of wavelength bands from .lambda.1 to AN outputted from the second port of the first light circulator and also outputting a light wavelength multiplexed signal having a wavelength within any of wavelength bands from .lambda.1 to AN to the second port of the first light circulator, a second terminal for receiving a light wavelength multiplexed signal, a third terminal and a fourth terminal each for dividing a light signal having a wavelength within any of the wavelength bands .lambda.1 to .lambda.N inputted into the first and second terminals into two portions, outputting the divided light signal, and receiving light signals having wavelengths from .lambda.1 to .lambda.N, the directional coupler outputting a synthesized light signal to the second terminal if a phase of a light signal inputted into the third terminal and returning the first terminal is reversed to that of a light signal inputted into the fourth terminal and returning to the first terminal, and also outputting a synthesized light signal to the first terminal if the phases of the two signals are identical, outputting a synthesized light signal to the first terminal if a phase of a light signal inputted into the third terminal and returning to the second terminal is reversed to that of a light signal inputted into the fourth terminal and returning to the second terminal, and also outputting a synthesized light signal to the second terminal if the phases of the two signals are identical; first to N-th wavelength selective reflectors reflecting light signals having wavelengths from .lambda.1 to .lambda.N and respectively connected to the third terminal of the directional coupler; first to N-th light phase shifters each provided in correspondence to each of the first to N-th wavelength selective reflector and shifting a phase of a light signal passing therethrough; N+1-th to 2N-th wavelength selective reflectors reflecting light signals having wavelengths from .lambda.1 to .lambda.N and respectively connected to the fourth terminal of the directional coupler; a light phase shifter control circuit for controlling a shaft rate for each of the first to N-th light phase shifters so that a phase of a light signal outputted from the first or second terminal of the directional coupler to the third and fourth terminals, reflected by any of the first to Nth wavelength selective reflectors, inputted into the third terminal and returning to the first or second terminal will be reverse to that of a light signal reflected by any of the N+1-th to 2N-th wavelength selective reflectors, inputted into the fourth terminal and returning to the first or second terminal in a case of a light signal to be branched, and also so that the former will be the same as the latter in a case of a light signal to be passed therethrough; a second light circulator having a first port for receiving a light wavelength multiplexed signal outputted from the second terminal of the directional coupler and also outputting a light wavelength multiplexed signal to the second terminal of the directional coupler, a second port for outputting a light wavelength multiplexed signal inputted into this first port, and a third port for receiving a light wavelength multiplexed signal and outputting the signal to the first port; a light receiver for receiving the light wavelength multiplexed signal outputted to the second port of the second light circulator; and a light transmitter for outputting a light wavelength multiplexed signal to the third port of the second light circulator.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first optical filter having a first terminal for receiving and outputting a light signal having a specified wavelength .lambda.i, a light signal having a wavelength .lambda.J, and a light signal having a wavelength other than the wavelengths .lambda.i and .lambda.j, a second terminal for outputting the light signal having a wavelength .lambda.i inputted into this first terminal and receiving a light signal having a wavelength .lambda.i, and a third terminal for outputting a light signal having a wavelength other than the wavelength .lambda.i inputted into the first terminal, the first optical filter outputting the light signal having a wavelength .lambda.i inputted into the second terminal to the first terminal; a second optical filter having a fourth terminal for receiving the light signal having a wavelength other than wavelength .lambda.i outputted from the third terminal of the first optical filter and a fifth terminal for outputting the light signal having a wavelength .lambda.j inputted into this fourth terminal; a light transmitter for outputting a light wavelength multiplexed signal for the second terminal of the first optical filter; and a light receiver for receiving the light wavelength multiplexed signal outputted to a second terminal of the second optical filter.
A wavelength multiplexed light transfer unit according to the present invention forms an optical filter with a grating light guide path in which a wavelength of a first reflected light is shorter than that of a second reflected light as the first optical filter.
A wavelength multiplexed light transfer unit according to the present invention comprises, a first optical filter having a first terminal for receiving and outputting a light signal having a specified wavelength .lambda.i, a light signal having a wavelength .lambda.j and a light signal having a wavelength other than the wavelengths .lambda.i, .lambda.j, a second terminal for outputting the light signal having the wavelength .lambda.i inputted into this first terminal, and a third terminal for outputting a light signal having a wavelength .lambda.i inputted into the thirst terminal, the first optical filter outputting the light signal having the wavelength .lambda.j inputted into the third terminal to the first terminal; a second optical filter having a fourth terminal for receiving a light signal having a wavelength .lambda.i outputted from the second terminal of the first optical filter and a fifth terminal for outputting the light signal having the wavelength .lambda.i inputted into this fourth terminal; a light transmitter for outputting a light wavelength multiplexed signal to the third terminal of the first optical filter; and a light receiver for receiving the light wavelength multiplexed signal outputted to the fifth terminal of the second optical filter.
A wavelength multiplexed light transfer unit according to the present invention formes an optical filter with a grating light guide path in which a wavelength of a first reflected light is shorter than that of a light signal transmitted from the light transmitter as the first optical filter.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.

Wavelength multiplexed light transfer unit and wavelength multiplexed light transfer system


A coupling device for attaching a towed vehicle, such as a trailer, to a towing vehicle, such as a truck, where the coupling device includes a securing assembly for removably securing the coupling device to the towing vehicle, a generally longitudinally extending inner assembly rigidly affixed to the securing assembly, and a generally longitudinally extending outer assembly. The outer assembly also includes an upper portion and a lower portion, with the upper portion being adapted to be rigidly affixed to the towed vehicle. The outer assembly has an inner diameter that is larger than an outer diameter of the inner assembly so that the outer assembly can be coaxially mounted over the inner assembly. The coupling assembly further includes a connecting member for connecting the inner assembly with the outer assembly, and a cushioning member that is positioned between the outer assembly and the inner assembly. The cushioning member is configured and arranged to primarily dampen lateral forces transferred between the inner assembly and the outer assembly. Optionally, the coupling device may also include a secondary cushioning assembly that is configured and arranged to primarily dampen axial forces transferred between the inner assembly and the outer assembly. As an additional option, the coupling device may also include a way of locking the securing assembly in a closed position so that unauthorized removal of the trailer from the truck can be prevented.

The present invention relates generally to a coupling device for connecting a towed vehicle, such as a trailer, with a towing vehicle, such as a truck. More particularly, the present invention relates to a coupling device that includes at least one cushion for dampening shocks from the lateral direction, and preferably includes a second cushioning assembly for dampening shocks from the axial direction.
Various types of coupling devices for connecting a towing vehicle with a towed vehicle are currently available. One popular way of connecting the towed vehicle to the towing vehicle utilizes two separate components--a ball and a socket--where the ball is affixed to the towing vehicle and the socket, within which the ball is to be seated, is affixed to the towed vehicle.
One specific type of ball and socket coupling device available for coupling heavyweight trailers to trucks is commonly referred to as a "gooseneck" coupler. The socket portion of the gooseneck coupler generally includes a long, vertically extending shaft (the "gooseneck") of several feet in length. This shaft is rigidly attached to the trailer so that it extends vertically downwardly from the trailer. The ball portion of the coupler is normally rigidly affixed to the rear portion of the truck, either directly over the rear axle or somewhat in front of the rear axle. With the ball portion positioned in this manner, a better weight distribution of the trailer is achieved because the weight of the trailer is not creating a downward force on the unsupported rearmost portion of the truck.
Gooseneck couplers are commonly used with larger trailers that include an overhang portion at the front end thereof. This overhang portion enables the truck/trailer combination to make relatively sharp turns without having the front of the trailer contact the back of the truck because the frontmost portion of the trailer is actually positioned over the top of the rearmost portion of the truck. In this manner, the trailer is free to pivot with respect to the truck through a relatively wide angle, without the loss of a significant amount of storage space in the trailer.
While gooseneck couplings are commonly used with the overhang trailers just described, they may also be used with trailers without an overhang portion, which instead include an A-frame extending horizontally from the front end of the trailer. The "A" shape of the A-frame may be seen when the trailer is viewed from above. Similar to the overhang, the A-frame also permits a relatively wide turning radius without the front of the trailer contacting the rear of the truck because the A-frame serves to provide sufficient distance between the front of the trailer and the back of the truck. Combinations of the A-frame setup and an overhang trailer are also available.
One problem with some of the currently available gooseneck coupling devices is caused by a lack of shock absorption, or at least insufficient shock absorption. During normal operation, shocks may be transferred between the trailer and the towing vehicle. These shocks may arise from a variety of sources such as uneven road surfaces, potholes, high winds acting upon the trailer, forces created by altering the velocity of the vehicle (i.e., starting or stopping the vehicle's motion), or the torsional forces that are created when the vehicle/trailer combination makes a turn. Further, as these shocks are created from a variety of sources, they also act in a variety of different directions. For example, the bulk of the force of a torsional shock occurs from the lateral direction, while the bulk of the force from a pothole occurs in the vertical direction, or along the axis of the vertically extending shaft.
No matter which direction the force of the shock is directed, similar consequences may result. Undampened shocks transferred within the coupling device can serve to weaken the materials of the coupling device, which may result in failure of the coupling device over time. More severe shocks can also instantaneously break the coupling device, if these severe shocks are not properly dampened. Besides requiring replacement, a broken coupling device can also lead to a dangerous traffic accident if the break occurs while traveling at high speeds, which is most often the condition under which a break is likely to occur.
An additional problem with the currently available coupling devices relates to the security of the coupling. After the trailer and the towing vehicle are connected to one another, they should be locked together. If no lock is available for the coupling, vandals or thieves may simply uncouple the trailer from the towing vehicle when the towing vehicle and trailer are parked. At minimum, this unauthorized uncoupling results in wasted time because the trailer and towing vehicle will have to be re-coupled. At worst, a valuable trailer and expensive cargo may be lost if the entire trailer, including the cargo therein, is stolen by being removed from the towed vehicle during an extended period of being parked.
Accordingly, in response to the problems discussed above, a primary object of the present invention is to provide an improved coupling device for coupling a towing vehicle with a towed vehicle, where the present coupling device includes adequate shock dampening.
Another object of the present invention is to supply an improved coupling device that includes shock dampening for laterally directed shocks.
A further object of the present invention is to provide an improved coupling device that includes sufficient shock dampening for axially directed shocks.
An additional object of the present invention is to provide an improved gooseneck coupling device with adequate shock dampening to avoid premature failure of the coupling.
Yet another object of the present invention is to supply an improved coupling that includes an effective, low-cost way of locking a trailer with a towing vehicle in a coupled state.


An object of the present invention is to provide organosilicon compounds having an excellent miscibility with other liquid crystal materials, low viscosity, and improved threshold voltage; to provide liquid crystal compositions comprising the organosilicon compound; and to provide liquid crystal display devices comprising the liquid crystal composition. The organosilicon compounds are expressed by the general formula (1) EQU Ra--A.paren open-st.Z.sub.1 --A.sub.1 .paren close-st..sub.m .paren open-st.Z.sub.2 --A.sub.2 .paren close-st..sub.n .paren open-st.Z.sub.3 --A.sub.3 .paren close-st..sub.o Rb (1). wherein at least one of Ra, Rb, Z.sub.1, Z.sub.2, and Z.sub.3 has --SiH.sub.2 --; Ra represents hydrogen atom or an alkyl group having 1 to 20 carbon atoms; at least one --CH.sub.2 -- in the alkyl group may be replaced by --SiH.sub.2 --, --O--, --S--, --CO--, --CH.dbd.CH--, --C.tbd.C--, or 1,3 -cyclobutylene; Rb represents a group selected from Ra, a halogen atom, or CN; each of A, A.sub.1, A.sub.2, and A.sub.3 represents a divalent cyclic group; Z.sub.1, Z.sub.2 and Z.sub.3 independently represent a covalent bond or --(CH.sub.2).sub.p --; at least one --CH.sub.2 -- in the --(CH.sub.2).sub.p -- may be replaced by --SiH.sub.2 --, --O--, --S--, --CO--, --CH.dbd.CH--, or --C.tbd.C--; p is an integer of 1 to 4; and m, n, and o are independently 0 or 1.

Display devices comprising liquid crystalline compounds (the term "liquid crystalline compounds" is used in this specification as a general term for the compounds exhibiting a liquid crystal phase and for the compounds which do not exhibit a liquid crystal phase but are useful as a component of liquid crystal compositions) have widely been employed for the display of watches, tabletop calculators, word processors, or the likes. These display devices have employed the optical anisotropy and dielectric anisotropy of liquid crystalline compounds.
While liquid crystal phases include a nematic liquid crystal phase, smectic liquid crystal phase, and cholesteric liquid crystal phase, the nematic liquid crystal phase has most widely been employed. As display mode, dynamic scattering (DS) mode, deformation of aligned phase (DAP) mode, guest/host (GH) mode, twisted nematic (TN) mode, super twisted nematic (STN) mode, and thin film transistor (TFT) mode are known.
Liquid crystalline compounds used in these display modes must exhibit a liquid crystal phase in a wide temperature range with room temperature being its center, must be sufficiently stable under conditions in which display devices are used, and further must have characteristics sufficient to drive liquid crystal display devices. However, no liquid crystalline compounds which satisfy such requirements by a single compound have been found up to now. Accordingly, it is the actual circumstances that several or several tens of liquid crystalline compounds are mixed to prepare liquid crystal compositions having required characteristics. These liquid crystal compositions are required to be stable against moisture, light, heat, and air which usually exist under the conditions in which display devices are used; to be stable against electric field and electromagnetic radiation; and to be chemically stable against compounds to be mixed, in addition. Further, it is considered to be necessary that the liquid crystal compositions have an appropriate value of physical properties such as optical anisotropy (.DELTA.n) and dielectric anisotropy (.DELTA. .epsilon.), depending on the display mode and the shape of display devices.
Further, it is important that each component in liquid crystal compositions has good miscibility to one another. Particularly, more reduction of consumptive electric power and more lowering of threshold voltage which largely contributes to the high speed response necessary for applying to a wider size of liquid crystal displays (E. Jakeman et al., Phys. Lett., 39A. 69 (1972)) are desired; and it is also important for the high speed response that the liquid crystal compositions have a low viscosity.
In order to achieve these purposes, various compounds have heretofore been developed. Among them, compounds which contain silyl group in the molecule and are expressed by the following formula (a), formula (b), or formula (c) are published by Laid-open Japanese Patent Publication Nos. Hei 6-9653, Hei 7-2878, or Hei 7-2879, respectively. ##STR1##
However, these compounds have a trialkylsilyl group formed by substituting three alkyl groups for all three hydrogen atoms linked to silicon atom in silyl group and thus do not have one, particularly two or more unsubstituted hydrogen atoms.
As will be understood from the results of the determination of physical properties conducted by the present inventors, for example, for a compound which has propyldimethylsilyl group and is expressed by the following formula (d), compounds having a trialkylsilyl group have such problems that their viscosity is remarkably high, and besides that their miscibility with other components of liquid crystal compositions is not sufficient. ##STR2##
Results of the determination of physical properties of the compound of the formula (d) described above are shown below:
First, the phase transition temperature of a nematic phase-an isotropic phase (NI), and viscosity (.eta.) at 20.degree. C. were determined on a liquid crystal composition ZLI-1132 produced by Merck Co., Ltd. to be 72.6.degree. C. and 26.7 mPa.s, respectively.
Then, 15 % by weight of the compound expressed by the formula (d) was added to 85 % by weight of the liquid crystal composition, and NI and .eta. of the composition thus obtained were determined to be lower than 15.degree. C. and 39.7 mPa.s, respectively.
From the results, it can be understood that the viscosity of liquid crystal compositions prepared by using the compound expressed by the formula (d) remarkably increased and their NI lowered by more than 50.degree. C. Further, the compound expressed by the formula (d) is inadequate for practical purposes since the compound added to the mother liquid crystal composition had a portion having a different NI and was poor in miscibility.

Organosilicon compound, liquid crystal composition, and liquid-crystal display element


A method is provided of displaying a GUI of a first dialog. The method includes, for a localizable display element of a set of localizable display elements of the first dialog, each element having an element name, (a) searching through a first chain of properties files of the first dialog for a display term mapped to by the element, (b) in response, determining that the display term is not found within the first chain, (c) in response, further searching through a second chain of properties files associated with a second dialog for the display term, the first chain being pre-configured to inherit properties from the second chain, and (d) when the display term is found within the second chain, displaying the display term found within the second chain in place of the localizable display element of the first dialog box on the GUI of the first dialog.

Graphical user interfaces (GUIs) often utilize dialog boxes to seek user input. In order to allow the dialog boxes to be localized to different languages and other localized configurations, some developers distribute each dialog box with one or more localized properties files to allow features of each dialog box to be properly localized.

Inheritance of properties files with locale chain support


The present invention provides a method for inhibiting the growth of filamentous microorganisms. The method includes the steps of adding effective amounts of a biocide and an enzyme. The enzyme of the present invention enhances the leakiness of the protective sheath around the filamentous microorganisms to allow the penetration of the biocide into the cells of the filamentous microorganisms.

The present invention relates generally to controlling the growth of microorganisms. More specifically, the present invention relates to methods for inhibiting the growth of filamentous microorganisms in industrial process waters.
The presence of microorganisms in waters, especially industrial waters, is a never-ending concern for industrial manufacturers. Examples of industrial waters where microorganisms can interfere with industrial processes include cooling tower waters, mining process waters, food processing waters, sugar reprocessing waters, wine and brewery waters and the like.
In particular, the growth of microorganisms in pulp and paper mill waters can adversely affect finished paper products. Paper mills provide extremely good conditions for the growth of microorganisms. The warm temperatures and rich carbohydrate containing fluids of paper machines provide ideal growth conditions for a variety of microorganisms. The contaminating microorganisms are capable of causing spoilage of pulp, furnish, or chemical additives. When deposits break loose and fall into the paper furnish, they result in quality loss or end product defects such as holes and spots. The end result is unsalable paper or paper sold at a lower value. Robertson, The use of phase-contrast microscopy to assess and differentiate the microbial population of a paper mill. TAPPI Journal, p. 83 (March 1993).
The presence of microorganisms within industrial water systems results in the formation of deposits of biological origin on industrial machines. These formation deposits give rise to: corrosion; breaks; increased down time; loss of yield; high chemical costs; odors; and expensive deposit control programs. In the paper mill industry, slime deposits are reportedly responsible for nearly 70% of all breaks, blockages and pump failures. Safade, Tackling the Slime Problem in a Paper-Mill. PTI, p. 280 (September 1988). Slime may be defined as an "accretion or accumulation caused by certain micro-organisms in the presence of pulp fiber, filler, dirt and other materials, mixed in varied proportions, having variable physical characteristics and accumulating at continuous changing rates." Id.
The conventional method of controlling microbial growth is through the use of biocides. Biocides are generally divided into two main groups: oxidizing; and non-oxidizing. These biocides act on the microorganisms in one of three ways: either by attacking the cell wall; the cytoplasmic membrane; or the cellular constituents. Id. at 282.
While biocides do inhibit microbial growth, economic and environmental concerns require improved methods. A problem with the use of biocides is that high levels of expensive chemicals are needed to control microbial growth. Moreover, such chemicals are highly toxic in the quantities known to be required for effective control of microbial populations. As a result, environmental regulations restrict the amount of biocides that can safely be discarded into the environment.
As an alternative to treatment with biocides, researchers posited the use of enzymes to control slime accumulation. U.S. Pat. No. 3,824,184 to Herbert J. Hatcher relates to the addition of levan hydrolase to industrial waters having a slime accumulation or potential slime problem. Similar to using a mixture of various biocides, the use of a multiple enzyme blend to control industrial slime is also known. See U.S. Pat. No. 5,071,765 to Christopher L. Wiatr.
While a biocide or an enzyme alone inhibits slime growth, researchers report that the combination of a biocide and an enzyme together provides even greater benefits. For example, U.S. Pat. No. 4,684,489 to Pederson et al. relates to the combination of a biocide and a polysaccharide-degrading enzyme to reduce slime accumulations. Past combinations focus on using an enzyme, such as levan hydrolase, to degrade the capsule layer around the cell of the microorganism. However, although the combination of the biocide and the levan hydrolase may provide increased control against some sorts of slime growth, it has no affect on sheathed microorganisms.
Conventional treatments fail to recognize the problems caused by filamentous microorganisms in water systems. A group of microorganisms, including the filamentous bacteria, enter industrial systems via the fresh waters. In a typical treatment program, the proper chlorination of waters is always recommended as a means to kill these microorganisms before they enter the system. Unfortunately, proper chlorination is often not a viable option since many filaments have a protective sheath that protects them from anti-microbial agents. While the industrial biocide/enzyme combinations that are presently available work well in killing unsheathed, nonfilamentous bacteria, they fail to limit or reduce the microbial population of filamentous bacteria. In fact, research has shown that 85% of the paper machine deposit samples for alkaline mills currently show filamentous bacteria as one of the major portions of the deposit matrix.
Therefore, a need exists for improved methods for controlling the growth of filamentous microorganisms in industrial process waters.

Treatment of process waters to destroy filamentous bacteria


The present invention relates to compounds which inhibit, regulate and/or modulate tyrosine kinase signal transduction, compositions which contain these compounds, and methods of using them to treat tyrosine kinase-dependent diseases and conditions, such as angiogenesis, cancer, tumor growth, atherosclerosis, age related macular degeneration, diabetic retinopathy, macular edema, retinal ischemia, inflammatory diseases, and the like in mammals.

The present invention relates to compounds which inhibit, regulate and/or modulate tyrosine kinase signal transduction, compositions which contain these compounds, and methods of using them to treat tyrosine kinase-dependent diseases and conditions, such as angiogenesis, cancer, tumor growth, atherosclerosis, age related macular degeneration, diabetic retinopathy, inflammatory diseases, and the like in mammals.
The following is provided as background information only and should not be taken as an admission that any subject matter discussed or that any reference mentioned is prior art to the instant invention.
Tyrosine kinases are a class of enzymes that catalyze the transfer of the terminal phosphate of adenosine triphosphate to tyrosine residues in protein substrates. Tyrosine kinases are believed, by way of substrate phosphorylation, to play critical roles in signal transduction for a number of cell functions. Though the exact mechanism of signal transduction is still unclear, tyrosine kinases have been shown to be important contributing factors in cell proliferation, carcinogenesis and cell differentiation.
Tyrosine kinases can be categorized as receptor type or non-receptor type. Receptor type tyrosine kinases have an extracellular, a transmembrane, and an intracellular portion, while non-receptor type tyrosine kinases are wholly intracellular.
The receptor-type tyrosine kinases are comprised of a large number of transmembrane receptors with diverse biological activity. In fact, about twenty different subfamilies of receptor-type tyrosine kinases have been identified. One tyrosine kinase subfamily, designated the HER subfamily, is comprised of EGFR, HER2, HER3, and HER4. Ligands of this subfamily of receptors include epithileal growth factor, TGF-α, amphiregulin, HB-EGF, betacellulin and heregulin. Another subfamily of these receptor-type tyrosine kinases is the insulin subfamily, which includes INS-R, IGF-IR, and IR-R. The PDGF subfamily includes the PDGF-α and β receptors, CSFIR, c-kit and FLK-II. Then there is the FLK family which is comprised of the kinase insert domain receptor (KDR), fetal liver kinase-1 (FLK-1), fetal liver kinase-4 (FLK-4) and the fms-like tyrosine kinase-1 (flt-1). The PDGF and FLK families are usually considered together due to the similarities of the two groups. For a detailed discussion of the receptor-type tyrosine kinases, see Plowman et al., DN&P 7(6):334-339, 1994, which is hereby incorporated by reference.
The non-receptor type of tyrosine kinases is also comprised of numerous subfamilies, including Src, Frk, Btk, Csk, Abl, Zap70, Fes/Fps, Fak, Jak, Ack, and LIMK. Each of these subfamilies is further subdivided into varying receptors. For example, the Src subfamily is one of the largest and includes Src, Yes, Fyn, Lyn, Lck, Blk, Hck, Fgr, and Yrk. The Src subfamily of enzymes has been linked to oncogenesis. For a more detailed discussion of the non-receptor type of tyrosine kinases, see Bolen Oncogene, 8:2025-2031 (1993), which is hereby incorporated by reference.
Both receptor-type and non-receptor type tyrosine kinases are implicated in cellular signaling pathways leading to numerous pathogenic conditions, including cancer, psoriasis and hyperimmune responses.
Several receptor-type tyrosine kinases, and the growth factors that bind thereto, have been suggested to play a role in angiogenesis, although some may promote angiogenesis indirectly (Mustonen and Alitalo, J. Cell Biol. 129:895-898, 1995). One such receptor-type tyrosine kinase is fetal liver kinase 1 or FLK-1. The human analog of FLK-1 is the kinase insert domain-containing receptor KDR, which is also known as vascular endothelial cell growth factor receptor 2 or VEGFR-2, since it binds VEGF with high affinity. Finally, the murine version of this receptor has also been called NYK (Oelrichs et al., Oncogene 8(1):11-15, 1993). VEGF and KDR are a ligand-receptor pair that play an important role in the proliferation of vascular endothelial cells, and the formation and sprouting of blood vessels, termed vasculogenesis and angiogenesis, respectively.
Angiogenesis is characterized by excessive activity of vascular endothelial growth factor (VEGF). VEGF is actually comprised of a family of ligands (Klagsburn and D'Amore, Cytokine & Growth Factor Reviews 7:259-270, 1996). VEGF binds the high affinity membrane-spanning tyrosine kinase receptor KDR and the related fms-like tyrosine kinase-1, also known as Flt-1 or vascular endothelial cell growth factor receptor 1 (VEGFR-1). Cell culture and gene knockout experiments indicate that each receptor contributes to different aspects of angiogenesis. KDR mediates the mitogenic function of VEGF whereas Flt-1 appears to modulate non-mitogenic functions such as those associated with cellular adhesion. Inhibiting KDR thus modulates the level of mitogenic VEGF activity. In fact, tumor growth has been shown to be susceptible to the antiangiogenic effects of VEGF receptor antagonists. (Kim et al., Nature 362, pp. 841-844, 1993).
Solid tumors can therefore be treated by tyrosine kinase inhibitors since these tumors depend on angiogenesis for the formation of the blood vessels necessary to support their growth. These solid tumors include histiocytic lymphoma, cancers of the brain, genitourinary tract, lymphatic system, stomach, larynx and lung, including lung adenocarcinoma and small cell lung cancer. Additional examples include cancers in which overexpression or activation of Raf-activating oncogenes (e.g., K-ras, erb-B) is observed. Such cancers include pancreatic and breast carcinoma. Accordingly, inhibitors of these tyrosine kinases are useful for the prevention and treatment of proliferative diseases dependent on these enzymes.
The angiogenic activity of VEGF is not limited to tumors. VEGF accounts for most of the angiogenic activity produced in or near the retina in diabetic retinopathy. This vascular growth in the retina leads to visual degeneration culminating in blindness. Ocular VEGF mRNA and protein are elevated by conditions such as retinal vein occlusion in primates and decreased pO2 levels in mice that lead to neovascularization. Intraocular injections of anti-VEGF monoclonal antibodies or VEGF receptor immunofusions inhibit ocular neovascularization in both primate and rodent models. Regardless of the cause of induction of VEGF in human diabetic retinopathy, inhibition of ocular VEGF is useful in treating the disease.
Expression of VEGF is also significantly increased in hypoxic regions of animal and human tumors adjacent to areas of necrosis. VEGF is also upregulated by the expression of the oncogenes ras, raf, src and mutant p53 (all of which are relevant to targeting cancer). Monoclonal anti-VEGF antibodies inhibit the growth of human tumors in nude mice. Although these same tumor cells continue to express VEGF in culture, the antibodies do not diminish their mitotic rate. Thus tumor-derived VEGF does not function as an autocrine mitogenic factor. Therefore, VEGF contributes to tumor growth in vivo by promoting angiogenesis through its paracrine vascular endothelial cell chemotactic and mitogenic activities. These monoclonal antibodies also inhibit the growth of typically less well vascularized human colon cancers in athymic mice and decrease the number of tumors arising from inoculated cells.
Viral expression of a VEGF-binding construct of Flk-1, Flt-1, the mouse KDR receptor homologue, truncated to eliminate the cytoplasmic tyrosine kinase domains but retaining a membrane anchor, virtually abolishes the growth of a transplantable glioblastoma in mice presumably by the dominant negative mechanism of heterodimer formation with membrane spanning endothelial cell VEGF receptors. Embryonic stem cells, which normally grow as solid tumors in nude mice, do not produce detectable tumors if both VEGF alleles are knocked out. Taken together, these data indicate the role of VEGF in the growth of solid tumors. Inhibition of KDR or Flt-1 is implicated in pathological angiogenesis, and these receptors are useful in the treatment of diseases in which angiogenesis is part of the overall pathology, e.g., inflammation, diabetic retinal vascularization, as well as various forms of cancer since tumor growth is known to be dependent on angiogenesis. (Weidner et al., N. Engl. J. Med., 324, pp. 1-8, 1991).
Accordingly, the identification of small compounds which specifically inhibit, regulate and/or modulate the signal transduction of tyrosine kinases is desirable and is an object of this invention.


A computerized method for determining a congestion level for a buffer associated with an SS7 link according to a first set of congestion rules includes receiving an abatement level and an onset level for the buffer. The method also includes generating, based on the received abatement level and the received onset level, more than two threshold levels for use by the congestion program. The congestion program is operable to generate a congestion level for the buffer according to a second set of rules different from the first set of rules. The method also includes providing the threshold levels to the congestion program, receiving from the congestion program a congestion level for the buffer based on the threshold values, the usage of the buffer, and the second set of rules, and converting the received congestion level into a converted congestion level.

Communications is becoming increasingly important in today's society. One component of some modern telecommunications systems is a link processor that accumulates multiple SS7 links and provides or receives data from a switch. Such accumulated data may be stored in a buffer within the link processor. Often it is important to assess the congestion level of the buffer.
Several conventional techniques exist for categorizing the congestion of the buffer in a link processor. Three of these techniques are referred to as the National Technique with multiple congestion levels and multiple congestion priorities (hereinafter "Technique 1"), the National Technique with multiple congestion levels without congestion priority (hereinafter "Technique 2"), and the International Technique without congestion level (hereinafter "Technique 3"). All three techniques are described in the standard identified as ITU Q.704, which is incorporated herein by reference. According to Technique 1, which is used in national signaling networks, nine different thresholds including three abatement thresholds, three onset level thresholds, and three discard thresholds are utilized to determine the congestion level of the buffer. The congestion level is typically reported as: cXdY, where X is the level of congestion and Y is the discard level. Technique 2, also used in national signaling networks, uses two thresholds, one onset threshold and one abatement threshold, and, in general, provides three different congestion levels. According to Technique 2, the congestion level is incremented or decremented based on the usage of the buffer as compared to a previous usage of the buffer. Technique 3, which is commonly used in international signaling networks, simply classifies the level of congestion of the buffer in the link processor as congested and uncongested. These three congestion categorization techniques involve nine, two, and two thresholds, respectively. These thresholds are often user specified.
Conventionally, functionality for determining the congestion level of the buffer based upon the provided threshold levels and usage of the buffer is programmed at Level 2 of the SS7 protocol stack, which is often done in assembly, or in hardware implementation. Consequently, modifications to any existing congestion program are difficult and have to be applied to different types of implementation.

Method and system for determining link congestion


An air seeder is provided with a pneumatic distribution system for delivering product through a plurality of primary tubes arranged in first and second rows. The pneumatic distribution system has a plenum housing having a plurality of outlet ports also arranged in first and second rows, each of said plurality of outlet ports associated with one of the primary tubes. A fan is in fluid communication with the upstream end of the plenum housing. A damper is mounted in the plenum housing upstream from the outlet ports for directing the air flow toward at least one of the first and second rows of primary tubes, and a perforated baffle plate is mounted in the housing between the damper and the outlet ports. The baffle plate has a plurality of openings adapted for governing the airflow into the outlet ports.

Air seeders are commonly towed by tractors to apply seed or fertilizer, or both simultaneously, to a field. An air seeder has as its central component a wheeled seed cart, which comprises one or more frame-mounted seed, tanks for holding product, generally seed or fertilizer or both. It is generally advantageous to tow a seed cart in combination with a tilling implement, one behind the other, to place the seed and fertilizer under the surface of the soil. Air seeders generally include a metering system for dispensing product from the tanks and a pneumatic distribution system for delivering the product from tank to soil.
The pneumatic distribution system of an air seeder generally utilizes a centrifugal fan to provide at least one airstream, which flows through the pneumatic distribution system to seed boots where product is deposited in the soil. Product is first introduced to the air stream by the metering system at a primary distribution manifold located below the metering system. Product is carried by the air stream through distribution lines to a series of secondary distribution manifolds, which in turn distribute product through distribution lines to seed boots mounted behind ground openers on the tilling implement so that the product may be evenly delivered to the span of ground (the "tillage") acted upon by the tilling implement.
In a double shoot configuration, equipment is provided for delivering two products separately through two different air streams (or sets of air streams) to the openers. Under many circumstances, it is desirable to have a mass flow rate and/or pressure in one set of air streams different from the rate of airflow in the other set of air streams. This is commonly achieved by inserting a device into the transition area between the blower and meter on the air cart which acts as a restricting element to divert a certain amount of airflow away from one set of air streams (and generally toward the other). Conventionally, the restricting element has taken one of a variety of forms, including, for example, a plate that is hinged at one end near the boundary between the two sets of air streams, a "guillotine" type door that can be lowered to restrict flow, a stationary plate inserted over the opening of the air stream, or a butterfly valve.
A problem common to the previously mentioned methods of restricting airflow is that the change in system response versus the change in position of the restricting element is decidedly non-linear throughout the range of movement of the restricting element. Therefore, an operator attempting to change mass flow rate or pressure in a set of primary tubes has difficulty determining the degree of movement of a restricting element required to effect the desired change.
It is therefore desirable to devise a pneumatic distribution system for an air seeder that enables an operator to correlate easily and reliably an adjustment made to the position of a restricting element to a resulting system response.

Plenum damper and baffle plate arrangement for pneumatic distribution system


Embodiments include measuring motion characteristics of the workpiece through the placement process. Since the component is placed on the workpiece with some force to ensure proper adhesion to the workpiece, some deflection of the workpiece is expected during the placement cycle. The placement force is adjusted to ensure that the component is safely placed into the solder paste or adhesive. Placement force is adjusted through a number of characteristics including: choice of spring tension in the nozzle; the length of the nozzle and the amount of over-travel into the board; the rigidity of the board and design; and the placement of the board support mechanisms. With proper adjustment of these characteristics and parameters, high quality placements onto the workpiece can be ensured.

Pick and place machines are generally used to manufacture electronic circuit boards. A blank printed circuit board is usually supplied to the pick and place machine, which then picks electronic components from component feeders, and places such components upon the board. The components are held upon the board temporarily by solder paste, or adhesive, until a subsequent step in which the solder paste is melted or the adhesive is fully cured.
Pick and place machine operation is challenging. Since machine speed corresponds with throughput, the faster the pick and place machine runs, the less costly the manufactured board will be. Additionally, placement accuracy is extremely important. Many electrical components, such as chip capacitors and chip resistors are relatively small and must be accurately placed on equally small placement locations. Other components, while larger, have a significant number of leads or conductors that are spaced from one another at a relatively fine pitch. Such components must also be accurately placed to ensure that each lead is placed upon the proper pad. Thus, not only must the machine operate extremely fast, but it must also place components extremely accurately.
In order to enhance the quality of board manufacture, fully or partially populated boards are generally inspected after the placement operation(s), both before and after solder reflow, to identify components that are improperly placed or missing or any of a variety of errors that may occur. Automatic systems that perform such operation(s) are highly useful because they help identify component placement problems prior to solder reflow. This allows substantially easier rework and/or the identification of defective boards after reflow that are candidates for rework. One example of such a system is sold under the trade designation Model KS Flex available from CyberOptics Corporation of Golden Valley, Minnesota. This system can be used to identify such problems as alignment and rotation errors; missing and flipped components; billboards; tombstones; component defects; incorrect polarity; and wrong components.
Identification of errors pre-reflow provides a number of advantages. Rework is easier; closed-loop manufacturing control is facilitated; and less work in-process exists between error generation and remedy. While such systems provide highly useful inspection, they do consume plant floor-space as well as programming time and maintenance efforts.
One relatively recent attempt to provide the benefits of after-placement inspection located within a pick a place machine itself is disclosed in U.S. Pat. No. 6,317,972 to Asai et al. That reference reports a method for mounting electric components where an image of a mounting location is obtained prior to component placement, and compared with an image of the mounting location after component placement to inspect the placement operation at the component level.
While the disclosure of Asai et al. marks one attempt to employ in-machine component level inspection, there remains much work to be done. For example, the disclosure of Asai et al. teaches acquiring two images before and after the placement of the component to determine placement characteristics of the component. While this approach is useful for determining the absence or presence of a component after placement, there are several important machine characteristics of the placement machine that can cause placement errors of components that this approach does not address.
One major contributing factor to the quality of the component placement is movement and vibration of the workpiece during the placement operation. Such vibration and/or motion of the workpiece can be caused by: the length of the nozzle; the distance of vertical travel of the nozzle during the placement cycle; the rigidity of the workpiece; and the placement of workpiece support.
To increase the viability of component level placement inspection in a pick and place machine, it would be advantageous to remove or minimize the effects of such motion. Reduction of vibration and/or motion effects would allow components to be placed more accurately thereby facilitating the cost effect manufacture or smaller-scale and/or higher density workpieces. Moreover, reduction or elimination of motion effects may allow components to be placed more quickly since the pick and place machine would not require as much time between ceasing relative x-y motion between the nozzle and the workpiece and placing the component.

Pick and place machine with workpiece motion inspection


An article for use as a negotiable instrument includes a substrate having a front side and reverse side; first machine-printed information on the substrate's front side including an account number associated with the negotiable instrument, and a unique identifier associated with the negotiable instrument, the first machine-printed information uniquely identifying the negotiable instrument; and second machine-printed information on the substrate's reverse side that corresponds to the first machine-printed information such that comparison of respective images of the substrate's front and reverse sides indicates that the images correspond to the same negotiable instrument.

This document relates to negotiable instruments (e.g., checks) and printing thereof.
A check is a type of negotiable instrument that orders payment of money from a bank account. The person writing the check, the drawer, has a transaction banking account (often called a checking account) where their money is held. The drawer writes the various details including the monetary amount, date, and a payee on the check, and signs it, ordering their bank or financial institution, known as the drawee, to pay that person or company the amount of money stated from the checking account specified by the check.
FIGS. 1A and 1B show front and back sides, respectively, of a "blank" check 100—that is, a check that has been printed, e.g., by a check printing company, but which has not yet been filled out by the drawer to specify details such as the amount or payee. As shown in FIG. 1A, the blank check includes a rectangular piece of paper check stock (or other suitable substrate) on which various information has been imprinted using suitable inks or the like. This information typically includes a bank routing number 102, which specifies a particular bank or financial institution, a bank account number 104 (unique to a particular customer or drawer), a check number 106 (typically a serial number of a particular check within a series of checks) that appears at two locations on the check as shown, a signature field 108 (for signature by the drawer), a payee field 116, a numeric monetary amount field 110, an alphabetic monetary amount field 112, and a "For" or "memo" field in which the drawer optionally may include notes, e.g., relating to the underlying transaction to which the check relates. In general, a drawer (or someone on his/her behalf) is required to fill out fields 108, 110, 112, 114, and 116 in order for the check to be legally recognized. The check 100 also may include drawer's information 118 such as the drawer's name and address, and bank information 120 such as the bank's name and address.
FIG. 1B shows the reverse side (equivalently, the "back" or "backside") of the check 100, which includes an endorsement field 122. Typically, the payee of the check 100 will provide his or her signature in the endorsement field 122 (and potentially other information such as "For Deposit Only") when presenting the check to the drawee for deposit or payment of the specified amount.
Recently, banks and other financial institutions have started providing customers with a convenient service known as "mobile check deposit" that eliminates the need for a payee to bring the physical check to his or her bank for deposit. Typically, a mobile check service operates as follows: using a mobile device, such as a smart phone, that has a camera and a special purpose software application installed and executing thereon ("the mobile app"), a payee takes photos of the front and reverse sides of a filled out check to be deposited. The mobile app then uploads the images to a server associated with the financial institution, which uses optical character recognition ("OCR") to determine the amount of the check, and to read other information on the check such as the routing number, the account number and the check number. Using this information, and subject to various check and verifications, the financial institution provisionally credits the payee's account by the amount of the check, and initiates communications within the banking network to cause the corresponding amount to be deducted from the drawer's account and transferred to the payee's account.

Negotiable instrument with dual-sided variable printing


A contact process for a semiconductor device containing a base region of a first conductivity type formed on a semiconductor substrate comprises formation of a first shallow layer of the first conductivity type on the base region, deposition of an insulator on the first shallow layer, etching the insulator and first shallow layer to form a contact hole, thermally driving the first shallow layer more deeply into said base region, formation of a second shallow layer of a second conductivity type on the base region at the bottom of the contact hole, filling a metal in the contact hole to contact the sidewall of the first shallow layer and the second shallow layer.

A conventional contact process for a power MOS device is considerably simple and is performed including heavily doping N+ source and P+ contact region for good ohm contact to reduce the contact resistance between the silicon material of the source and the metal thereof. In this process, the masks to define the N+ region for the source and to define the contact hole are required to overlap well with each other for the formation of good ohm contact.
FIGS. 1A–1G illustrate a conventional contact process for a source contact of an N-type trench power MOSFET. As shown in FIG. 1A, a power MOSFET contains an N− epitaxial layer 12 on an N+ substrate 10, and on the N− epitaxial layer 12, a gate 16 as well as a P-type base region 14 are formed. The contact process comprises defining and implanting an N+ region 18 for the source with a mask 20, and typically, arsenic (As) is implanted thereto and then thermally driven in to diffuse to be the N+ region 18, as shown in FIG. 1B.
Subsequently, as shown in FIG. 1C, an insulator 22 preferably of NSG/BPSG is deposited and annealed. Then, a contact hole 26 is defined with a mask 24 and etched, as shown in FIG. 1D. Afterward, a P+ region 28 is implanted for example with boron difluoride (BF2) through the contact hole 26, as shown in FIG. 1E.
In FIG. 1F, annealing and blanket etching are performed to smooth the insulator 22 and to remove the defective surfaces of the N+ region 18 and the P+ region 28. Finally, metals 30 and 32 are deposited for the source and drain electrodes, as shown in FIG. 1G.
In such structure of a power MOS, the extended length of the N+ junction resulted from the lateral diffusion is nearly the same as the depth thereof by vertically driven in, such that the actual length of the N+ region is much greater than the length defined by the source N+ mask. For the power MOS, in addition to the limitation of the scale down to the unit cell of the power MOS by the longer source N+ region, the current capability of the device itself is reduced, resulting in second breakdown of the trench power MOSFET and latch-up of the insulated-gate bipolar transistor (IGBT).

Contact process and structure for a semiconductor device