An optical fiber coupler according to the present invention comprises two optical fibers which each include a core portion serving to propagate light and a clad portion surrounding said core portion, the two optical fibers extending substantially in parallel in a same flat plane, and a melting portion in which the clad portions of the two optical fibers are fused together substantially in a line contact. Two optical fibers are arranged in parallel to permit at least parts of the clad portions to be brought into contact with each other. In this state, the two optical fibers are heated and fused mutually substantially in a line contact and are further drawn for fabrication thereof. The optical fibers are heated preferably employing an electric ceramic microheater. The two optical fibers may be same or different in structural parameters.

This application is based on Patent Application No. 2001-58828 filed Mar. 2, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a wide-bandwidth optical fiber coupler with less polarization dependency loss and less excessive loss, and a method and an apparatus for easily and stably fabricating the optical fiber coupler.
2. Description of the Related Art
An optical coupler with less wavelength dependency, e.g. a wide-bandwidth optical fiber coupler for branching and coupling a wide-bandwidth optical signal may enjoy wide utilization as various optical parts for use in general optical fields and micro optical fields and in optical communication and optical data processing.
Upon fabrication of such a wide-bandwidth optical fiber coupler, there is known a prior art method wherein one of two optical fibers possessing the same structural parameters of the optical fibers is previously heated and drawn to force the structural parameters of these two optical fibers to be different or two optical fibers possessing mutually different structural parameters of the optical fibers are used, melted and drawn in a twisted state of the fibers.
Referring to FIGS. 29 to 31, fabrication procedures of such a prior art wide-bandwidth optical fiber coupler is illustrated in schematically. Opposite ends of one optical fiber 1 is held on a pair of carrying blocks 2. A coating is removed from a central portion of the optical fibers 1 located between these carrying blocks 2 as illustrated in FIG. 29. A distance between the pair of the carrying blocks 2 is increased while heating an exposed optical fiber strand 3. The portion of the optical fiber strand 3 is preliminarily drawn, as illustrated in FIG. 30. There are twisted a preliminarily drawn optical fiber 5 and the optical fiber 1 which optical fiber 1 is not preliminarily drawn and in which a coating thereof is only removed from a central portion thereof are twisted along that portions of the optical fiber strands. In this state, both ends of these optical fibers 1 and 5 are again held on the pair of the carrying blocks 2. The distance between the pair of the carrying blocks 2 are increased while again heating the portions of the twisted optical fiber strands 3 with the burner 4, as illustrated in FIG. 31. The two optical fiber strands 3 are hereby melted and drawn at those twisted portions to obtain such an optical fiber coupler 6 as illustrated in FIG. 32.
When a wide-bandwidth optical fiber coupler 6 with reduced wavelength dependency is fabricated, the foregoing prior art method where there are used two optical fibers with mutually different structural parameters requires that two kinds of optical fibers previously should be fabricated. This is not general in view of the production cost.
To solve this difficulty, the following method is exclusively employed: two optical fibers of the same kind are prepared, one of which is preliminarily drawn to change the parameters concerning the structure.
The prior art method illustrated in FIGS. 29 to 31, however, needs to preliminarily draw the optical fiber strand 3 by about 10 mm using the burner 4. In the method, it is essentially impossible to finely control heating temperature for the optical fiber strand 3 in the unit of several tens of xc2x0 C. for example so as to prevent a wire diameter from being varied. In the prior art method, the wire diameter of a portion of the preliminarily drawn optical fiber strand 3 is narrowed, so that it is necessary to mutually twist the preliminarily drawn optical fiber strand 3 and the optical fiber strand 3 of the optical fiber 1 from which sheath is only simply removed for securely bringing them into close contact. As illustrated in FIG. 23, when the two optical fibers 1 and 5 are mutually twisted, it is necessary to apply tension uniformly to those two optical fibers 1 and 5, so that those fibers should be twisted with subtle discretion. The prior art method therefore suffers from difficulty that work is complicated with deteriorated reproducibility. The prior art method further suffers from a difficulty that the optical fibers 1 and 5 are subjected to twisting, so that the optical fiber strand 3 suffers from larger polarization dependency owing to internal stress produced in itself, and allows polarization dependency loss (hereinafter, may be simply referred to PDL.) to be increased together with increased excessive loss.
Referring to FIG. 33, there is illustrated wavelength dependency of a coupling ratio, i.e. a branch ratio between a symmetrical optical fiber coupler A where an optical coupling portion is configured symmetrically and asymmetrical wide band optical fiber couplers B and C where an optical coupling portion is not symmetrical). For such a branch ratio of a general symmetrical optical fiber coupler in which parameters concerning the structures of two optical fibers constituting an optical fiber coupler A are same for each other, it varies periodically from 0 to 100% owing to the wavelength of an optical signal. In contrast, for wide band optical fiber couplers B and C possessing different parameters concerning the structures of two optical fibers constituting an optical coupling portion, a branch ratio is reduced to a specific value, 100% or less by combining optical fibers with outer diameters of clad portions thereof for example being respectively 115 xcexcm and 125 xcexcm. There is thereupon utilized a flat portion located in the vicinity of the maximum of the just-mentioned branch ratio. As illustrated in FIG. 33, the wide-bandwidth optical fiber coupler B has the branch ratio of 50% at wavelength of 1.4 xcexcm and the wide-bandwidth optical fiber coupler C has the optical branch ratio of 20% at wavelength of 1.4 xcexcm. It can be understood therefrom that a change in the branch ratio in the vicinity of the maximum branch ratio is more flattened than the wavelength characteristic of the symmetrical optical fiber coupler A would be.
For fabricating the aforementioned wide-bandwidth optical fiber coupler there is known a method proposed by International Application PCT/GB 86/00445. More specifically, one single mode optical fiber is preliminarily drawn, and the preliminarily drawn optical fiber and another optical fiber not preliminarily drawn are combined, melted and drawn to successfully obtain a wide-bandwidth optical fiber coupler 6 as illustrated in FIG. 34 and FIG. 35 which illustrates a cross sectional structure viewed along XXXVxe2x80x94XXXV shown in FIG. 34. In the resulting optical fiber coupler 6, a propagation constant of the one single mode optical fiber 1 is altered with the aid of preliminary drawing to obtain different parameters from those concerning the structure of the optical fiber 5 not preliminarily drawn with the maximum branch ratio brought into a specific value less than 100%, and a flat wavelength characteristic in the vicinity of the maximum value of the branch ratio is utilized. In FIG. 34, designated at 7a is a core portion, 7b is a clad portion, 8 is preliminarily drawn portion, and 9 is a melted drawn portion.
The aforementioned prior art fabrication method for the wide-bandwidth optical fiber coupler 6 using the preliminary drawing, however, has a difficulty that uniform preliminary drawing is difficult. More specifically, uniform heating control for the preliminary drawn portion 8 is difficult to make impossible precision configuration control and hence to make it difficult to obtain a uniform outer diameter of the melted drawn portion 9. The optical fibers 1 and 5 might thereupon been sometimes bent upon processing the resulting wide-bandwidth optical fiber coupler 6. This might cause set value control for the branch ratio to be difficult and therefore accuracy of flatness of the branch ratio of the drawn optical fiber to be unsatisfactory with the very bad yield of the coupler.
To solve the aforementioned difficulty with the preliminary drawing described above, Japanese Patent Application Laid-Open No. 2-171705 discloses a method wherein two optical fibers possessing mutually different propagation constants are drawn with the mutually equal drawing, and are then melted and further drawn. Further, Japanese Patent Application Laid-Open No. 2-259704 discloses another method wherein between two single mode optical fibers including clad portions thereof having mutually different diameters thereof the one optical fiber having the same outer diameter as that of the same optical fiber at the other end is previously melted and connected with both ends of the other optical fiber, and then the two optical fibers are melted and drawn.
Also in these two methods, however, structural parameters of the two optical fibers are made asymmetrical and the maximum value of the branch ratio is brought to a specific value less than 100%, and wavelength flatness in the vicinity of the maximum value is utilized. The degree of melting is still high so as to provide close coupling.
When two optical fibers having the same structural parameters are mutually melted and drawn to fabricate a symmetrical optical fiber coupler, the maximum value of the branch ratio thereof becomes 100% as illustrated in FIG. 33. Thereupon, it is contemplated from the viewpoint of the neighborhood of the maximum value of the branch ratio being used that a wide-bandwidth optical fiber coupler having an arbitrary branch ratio can not been fabricated. Accordingly, a wide-bandwidth optical fiber coupler is conventionally fabricated by preparing two optical fibers having mutually different structural parameters such as a diameter of a clad portion or combining a preliminary drawn optical fiber and a not preliminarily drawn optical fiber.
In optical fiber communication, there are required wide-bandwidth optical fiber couplers possessing various branch ratios not only of 50% but also of 20, 10, 5, 2%, etc. Further, each time a branch ratio is altered, there must be prepared optical fibers having different structural parameters such as a core diameter, a specific refractive index, and a clad outer diameter, resulting in the high fabrication cost. When a wide-bandwidth optical fiber coupler fabricated with a different clad diameter optical fiber is assembled in an optical communication network, it is necessary to connect a different clad diameter optical fiber with opposite ends of the assembled optical fiber. It is generally not easy technically to connect optical fibers possessing different parameters concerning such a structure mutually in series, resulting in the costing-up of fiber fabrication.
In view of the above description it is an object of the present invention to provide a method and an apparatus capable of easily fabricating with excellent reproduction a wide-bandwidth optical fiber coupler that possesses less polarization dependency loss and less excessive loss.
It is another object of the present invention to provide an optical fiber coupler that eliminates a preliminary drawing process, and a method capable of inexpensively fabricating the foregoing optical fiber coupler.
A first aspect of the present invention is an optical fiber coupler which comprises two optical fibers each including a core section for serving to transmit light and a clad section surrounding the former core section, the two optical fibers extending substantially parallel in a same flat plane, and a melting section where the clad sections of the two optical fibers are mutually melted substantially in a line contact state.
The present invention is grounded on the appreciation that the wavelength dependency of the branch ratio of the optical fiber coupler with low melting rate tends to become less than that of the branch ratio of the optical fiber coupler with high melting rate, as shown in FIG. 36.
In the optical fiber coupler according to the first aspect of the present invention, outer diameters of clad portions of two optical fiber couplers may be substantially equal to each other. In this case, even if a coupling rate of the optical fiber coupler is 100%, the optical fiber coupler with arbitrary branch ratio can be provided by making use of a portion with a mild modulation of the branch ratio.
It is advantageous that the branch ratio of the optical fiber coupler increases substantially monotonically in response to the wavelength of light that propagates in an optical fiber, and in the wavelength range of the light of from 1.3 xcexcm to 1.55 xcexcm the amount of a change in the branch ratio effectively lies within 20%.
In accordance with the first aspect of the present invention, in the wavelength range of light of from 1.3 xcexcm to 1.55 xcexcm the branch ratio of the optical fiber coupler may be 1 to 20%.
Outer diameters of clad portions of two optical fibers may be mutually different.
It is preferable that when the size of the maximum width size of the melting portion is assumed to be W, and outer diameters of the clad portions of the two optical fibers in the melting portion are assumed d1 and d2 respectively, a melting rate C represented by
C=[1xe2x88x92{W/(d1+d2)}]xc3x97100
lies in the range of from 0.5 to 10%, preferably 1 to 7% which range corresponds to xe2x80x9csubstantially line contact statexe2x80x9d in the present invention.
A second aspect of the present invention is a method for fabricating an optical fiber coupler which comprises the steps of arranging mutually in parallel two optical fibers each including a core portion serving to propagate light therethrough and a clad portion surrounding the core portion to bring at least parts of the clad portions into close contact, melting mutually parts of the clad portions of the two optical fibers substantially in a line contact state by heating these clad portions in a mutual close contact state of at least parts of the clad portions, and heating and drawing the mutually melted two optical fibers.
In the method for fabricating the optical fiber coupler according to the present invention, the step of mutually melting the clad portions of the two optical fibers may include a step of heating the clad portions to 1500xc2x0 C. or higher.
The step of heating and drawing of the two optical fibers mutually melted may further comprise the steps of lowering heating temperature with respect to the two optical fibers after those optical fibers are melted, drawing melted portions of the two optical fibers in the state where the heating temperature is lowered, forcing monitor light to impinge from a one end side of any of the two optical fibers and detecting the monitor light from the other end side of at least one of the two optical fibers to measure a branch ratio thereof, and interrupting the drawing of the melted portions of the two optical fibers at the time when the branch ratio reaches a predetermined value. Therefore, an optical fiber coupler having a desired branch ratio can be obtained.
It is preferable that when the size of the maximum width size of the melting portion is assumed to be W, and outer diameters of the clad portions of the two optical fibers in the melting portion are assumed d1 and d2 respectively, a melting rate C represented by
C=[1xe2x88x92{W/(d1+d2)}]xc3x97100
lies in the range of from 0.5 to 10%, preferably 1 to 7% which range corresponds to xe2x80x9csubstantially line contact statexe2x80x9d in the present invention. Therefore, the optical fiber coupler possessing excellent characteristic can be obtained.
For the heating for the optical fiber an electric ceramic microheater may be preferably employed in view of the ease of temperature control. It is then ensured that heating temperature for the optical fiber becomes accurately controllable to smoothly change the diameter of the optical fiber strand as well as successfully obtain a long drawn region possessing a uniform wire diameter. This assures fabrication of an optical fiber coupler possessing excellent characteristics. It is additionally possible to preliminarily draw, in the state where two optical fibers are previously arranged in parallel very closely, only the one optical fiber.
There may be substantially equal outer diameters of the clad portions of the two optical fibers where at least parts of the clad portions are brought into contact with each other.
The two optical fibers where at least parts of the clad portions are brought into contact with each other may be different from each other in their structural parameters. Therefore, it becomes possible to melt such two optical fibers without twisting them, whereby a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably.
In this case, it is possible to further provide a step in which only one of the two optical fibers are preliminarily drawn to bring structural parameters thereof to different ones. Therefore, melting of two optical fibers is ensured without twisting them, and a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably at the low cost.
The method for fabricating an optical fiber coupler may further comprise the steps of arranging mutually in parallel two optical fibers having the same structural parameter, and preliminarily drawing only one of the two optical fibers to provide mutually different structural parameters thereof. Therefore, melting of two optical fibers is ensured without twisting them, and a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably at the low cost.
In this case, the step of preliminarily drawing one optical fiber may include the steps of heating both the two optical fibers to distortion eliminating temperature or higher, and drawing only one of the heated two optical fibers. Otherwise, the same step may be performed at a heating temperature where one optical fiber does not melt with the other optical fiber. Therefore, it becomes possible to previously hold the two optical fibers closely and hence improve workability whereby an optical fiber coupler effectively ensured.
A third aspect of the present invention is an apparatus for fabricating an optical fiber coupler which comprises a pair of fiber carrying blocks for holding longitudinal opposite sides of two optical fibers possessing mutually different structural parameters, fiber fixing means provided on the fiber carrying blocks for fixing the two optical fibers to the fiber carrying blocks, a base for carrying the pair of the fiber carrying blocks movably longitudinally of the optical fibers, carrying block drive means for moving the pair of the fiber carrying blocks mutually oppositely in the opposite directions of the fiber carrying blocks, fiber forcing means provided on the fiber carrying blocks for forcing the two optical fibers such that parts of portions of the optical fibers from which coatings of the two optical fibers are removed and brought into contact with each other, and a heater mounted on the base movably in the direction intersecting the longitudinal direction of the two fibers along a flat plane containing the two optical fibers for heating the two optical fibers.
In accordance with the third aspect of the present invention, melting of two optical fibers is ensured without twisting them, and a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably at the low cost.
A fourth aspect of the present invention is an apparatus for fabricating an optical fiber coupler which comprises a pair of first fiber carrying blocks for holding longitudinal opposite sides of a first optical fiber, first fiber fixing means provided on the pair of the first fiber carrying blocks to fix the first optical fiber to the fiber carrying blocks, a pair of second fiber carrying blocks for holding a second optical fiber at longitudinal opposite sides thereof in parallel with the first optical fiber, second fiber fixing means provided on the pair of the second fiber carrying blocks for fixing the second optical fiber to the second fiber carrying blocks, a base for movably carrying the first and second fiber carrying blocks longitudinally of the optical fiber, first carrying block drive means for mutually oppositely moving the pair of the first fiber carrying blocks in opposite direction thereof, second carrying block drive means for mutually oppositely moving the pair of the first fiber carrying blocks in the opposite direction thereof, fiber biasing means provided on the first and second fiber carrying blocks for biasing the first and second optical fibers such that parts of portions of the first and second optical fibers where coatings thereof are removed make contact with each other, a heater mounted movably in a direction intersecting a longitudinal direction of the optical fibers along a flat plane containing the first and second optical fibers for heating the first and second optical fibers, and heater movement means for driving the heating means in the direction intersecting the longitudinal direction of these optical fibers along a flat plane containing the first and second optical fibers.
In accordance with the fourth aspect of the present invention, melting of two optical fibers is ensured without twisting them, and a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably at the low cost.
In the apparatus for fabricating an optical fiber coupler according to the third or fourth aspect of the present invention, there can be further provided a pair of coupling means for respectively integrally coupling first and second fiber carrying blocks located mutually closely. Therefore, when two optical fibers are heated, melted, and drawn, it becomes possible to securely integrally move them.
The fiber forcing means may include a fixing pin fixed to any one of the first and second fiber carrying blocks, a plunger disposed oppositely to the fixing pin between the first and second optical fibers and being movable oppositely to the fixing pin, and plunger fixing means for fixing the plunger at a predetermined position oppositely to the fixing pin. Therefore, melting of two optical fibers is ensured without twisting them, and a high quality wide-bandwidth optical fiber coupler with less PDL and less excessive loss is ensured stably at the low cost.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.

Optical fiber coupler, manufacturing method and apparatus thereof


A device for suppression of leakage of the magnetic flux in a cathode ray tube display apparatus which comprises at least a cathode ray tube having a face plate and horizontal beam deflection circuit generating the leakage, the deflection circuit comprising a pair of upper and lower coils each of which has a bend-up section producing a first magnetic field which deflects an electron beam of the cathode ray tube, and a second magnetic field produced as the leakage the first and second magnetic field forming a boundary plane therebetween, so that two boundary planes are formed of said upper and lower deflection coils, respectively, said device comprising; a pair of conductors each of which has a main portion and a lead portion connected to the main portion, said main portion of the pair of conductors being disposed approximately within said boundary plane and along approximately top and bottom rims of the face plate, respectively, said lead portion of the pair of conductors disposed along a side wall of a funnel of the cathode ray tube in such a form that one end of the lead portion is bent along a side rim of the face plate to couple with said main portion and another end of the lead portion extends toward a rear of the horizontal beam deflector, the pair of conductors being driven with a current proportional to a horizontal deflection current flowing through the horizontal beam deflectors.

This invention relates to a method and a device for suppression of leakage of magnetic flux in a cathode ray tube display apparatus, which is adapted to suppress leakage magnetic flux generated from the deflection yoke.
There are many display apparatuses of the type utilizing a magnetic field generated from the deflection coil, etc. as the method of deflecting an electron beam. For this reason, in the display apparatus of this kind, a magnetic flux from the deflection coil, etc. leaks out from the surrounding of the cathode ray tube. Such an unnecessary electromagnetic ray may exert bad or adverse influence on the operation of electronic equipment in the vicinity thereof.
Recently, studies on the influence exerted on the human being and animals of the magnetic field have been conducted. For example, a magnetic field from the cathode ray tube is considered to be also harmful. In view of this, the research institution of SSI (Statens Stralskydds Institut) in Sweden has announced that in regard to the super low frequency magnetic field, with the point within 15 cm from the center of the display surface of the cathode ray tube being as a center, as recommended values of the change rate, i.e., time-derivative (dB/dt) of a magnetic flux density at 80 positions positions on the spherical body having a radius of 65 cm and the strength of a magnetic flux density in the frequency band of 10 to 300 KHz, the change rate of the maximum magnetic field is set to a value lower than 25 mT (mili tesla), and the strength of the maximum magnetic flux density is set to a value lower than 50 nT (nano tesla).
In the above-described description, T represents Tesla which is the unit of the strength of a magnetic field, and 1 T=10000 Gauss and 1 mT=10 Gauss.
For allowing the change rate of a maximum magnetic field as the entirety of the display apparatus to satisfy the value lower than 25 mT/sec, it is indicated by the display manufacturers and sellers (e.g., IBM, etc.) that the change rate of the maximum magnetic field should be a value lower than 15 mT/sec as the standard requirement in the state of the cathode ray tube to which the deflection yoke is attached, i.e., the cathode ray tube display apparatus what is called an ITC (Integrated Tube Component).
For conventional technologies for suppression of leakage magnetic flux from the deflection yoke on the display surface of the cathode ray tube, there were two prior arts described below.
The first prior art is the technology shown in FIGS. 1A to 1C. This has been already filed at the Japanese Patent Office by N. V. Philips Gloellampenfabrieken (Japanese Patent Application Laid Open No. 223952/1987).
Namely, FIGS. 1A to 1C show examples where an electric wire 1 is electrically coupled to the deflection unit and the electric wire 1 is disposed on a face-plate 2, respectively. In these figures, reference numerals 3a and 3b represent ordinary connection terminals of the deflection unit, respectively.
In the case of the example of FIG. 4A (system I), the electric wire 1 is connected in series with deflection coils 4a and 4b, and two electric wire sections 1a and 1b in a horizontal direction of the electric wire are directly attached to the upper and lower side edge portions of the face-plate 2, or are attached in a manner that they are extremely close thereto, respectively.
In the case of the example of FIG. 1C (system II), for compensating a stray magnetic flux of individual deflection coils, a deflection coil 4a is coupled in series with the upper side electric wire section 1a in a horizontal direction, and a deflection coil 4b is coupled in series with the lower side electric wire section 1b in the horizontal direction.
In the case of the example of FIG. 1B (system III), a control current source 5 is disposed between the deflection coils 4a and 4b and the electric wire sections 1a and 1b. In this case, the electric wire sections are wound a plurality of times, i.e., as a plurality of loops at the upper and lower side edge portions of the faceplate 2.
The second technology has been proposed by the same assignee as one of this invention. (Japanese Patent Application No. 156411/1987, EPC Application No. 89306338.8).
Namely, the example shown in FIG. 2 (system IV) is as follows. In this figure, reference numeral 6 represents a cathode ray tube, reference numeral 7 a deflection coil, and reference numerals 8a and 8b electric wires for producing cancellation magnetic flux, respectively. The electric wires 8a and 8b are disposed in a manner that they are wound on the upper and lower halves around the display surface 10, respectively. A horizontal deflection current is delivered in a direction indicated by an arrow in the figure. The deflection coil 7 is provided in the vicinity of an electron gun 9 so that is deflects an electron beam. A horizontal deflection current is delivered from the deflection circuit to the deflection coil 7.
At this time, a signal from the deflection circuit is delivered to the deflection coil 7, and this signal is also delivered to the electric wires 8a and 8b, and varies in synchronism with the signal flowing in the deflection coil 7.
The leakage magnetic flux was measured under the following condition in connection with the systems I to IV according to the above-described first and second prior arts.
For measuring the recommendated value announced by the above SSI in Sweden, a meter (MAGNETIC FIELD METER MODEL MFM 1000) capable of measuring a low frequency leakage magnetic field developed by Combinova Company in Sweden is used. An actual measurement was conducted as follows. As shown in FIG. 3, antennas corresponding to magnetic fields from three directions were installed at positions of A, C and E. The CRT display apparatus was then rotated clockwise and anticlockwise using the central point of the display apparatus as a center. The change rate of the magnetic field and the strength of the magnetic field under the condition in FIGS. 3 and 4 (particularly at positions and angles of the antenna relative to the cathode ray tube), i.e., at the positions where antennas are installed, labelled A0, A1, A2, A14, A15, C0, C1, C2, C14, C15, E0, E1, E2, E14, E15, are measured by allowing a sawtooth current 7.8 A p-p having a horizontal deflection frequency of 20 KHz to flow in a horizontal deflection coil (not shown) of the deflection yoke 12 of the cathode ray tube 11, and by allowing a sawtooth current having a vertical deflection frequency of 60 Hz to flow in a vertical deflection coil (not shown).
As a result, the maximum values and the minimum values of measured values at 15 positions in accordance with the above-described systems I to IV are as shown in FIG. 5.
All the measured values shown in this figure vary to much extent depending upon the wiring position of a lead wire for conducting a current into the electric wire for cancellation of leakage magnetic flux provided in the vicinity of the face-plate of the cathode ray tube. By changing the wiring position of the lead wire, a value at a specific position on the above-mentioned electric wire may be minimized. However, if measurement is made with the lead wire in the above-described first and second prior arts hanging down in a direction of gravity, it was impossible to minimize, in a well-balanced manner, measured values on the measurement spherical body constituted by the above-described 15 positions. Further, cathode ray tube display apparatus could be hardly mass-produced in such an unbalanced state.
Meanwhile, when, as in the above-described arrangement shown in FIGS. 1A and 1B, two electric wire sections 1a and 1b for cancellation of leakage magnetic flux along the upper and lower side edge portions of the face-plate 2 are connected by electric wires indicated by broken lines, which are subjected to wiring on the diagonal line, a magnetic flux in the same direction as that of a magnetic flux (leakage flux) produced form the deflection coils 4a, 4b is produced across the electric wire on the diagonal line. Not only the leakage magnetic flux cancellation effect by the electric wire sections 1a and 1b can be reduced, but also it could not be expected to uniformly exhibit the leakage magnetic flux cancellation effect on the above-described spherical body designated by the SSI institution.
Further, also in the arrangement shown in FIG. 1C, a magnetic flux generated form the electric wire indicated by broken lines becomes effective in a direction of decreasing the leakage magnetic flux cancellation effect. Thus, a sufficient effect could not be expected.
Furthermore, in the above-described second prior art (EPC Appln. No. 89306338.8), it is suggested that the source from which a leakage magnetic flux is produced in front of the display surface of the cathode ray tube is a bend-up portion of the horizontal deflection coil.
However, as shown in FIG. 8 which will be described later, how an actual leakage magnetic flux is produced is such that leakage magnetic flux B.sub.2b radiated in a forward direction of the fluorescent display surface 53a is extremely greater than the magnetic flux B.sub.1 produced form the bend-up portions 50.sub.a1 and 50.sub.b1 of the horizontal deflection coils 50a and 50b. Thus, it is necessary to produce a cancellation magnetic flux in a direction opposite to that of the second prior art.
When a leakage magnetic flux cancellation magnetic flux is produced in a direction as indicated by the patent specification according to the above-described second prior art, a far greater leakage magnetic flux would be produced as compared to the case where there is no electric wire for cancellation of leakage magnetic flux.
In addition, as shown in FIGS. 11, 12 and 17 which will be described later, a leakage magnetic flux B.sub.2c in the same direction as that of the main magnetic flux B.sub.2a component is produced also from the side surface portions of the cathode ray tube or the side surface portions of the deflection yoke. Since this leakage magnetic flux B.sub.2c exerts an effect also in the forward direction of the display surface, unless such a leakage magnetic flux B.sub.2c is canceled along with other leakage magnetic flux, the leakage magnetic flux of the entirety of the cathode ray tube display apparatus cannot be reduced to a low level. Particularly cancellation of the leakage magnetic flux B.sub.2c toward the side surfaces could not be imagined by the prior art.
Accordingly, none of the above-described prior arts can reduce the strength of an unnecessary magnetic flux over the entire periphery of the cathode ray tube, and manufacture apparatus which can satisfy the standard requirement of recent display manufacturers and sellers. Thus, it was necessary to stably reduce the leakage magnetic flux radiated from the cathode ray tube display apparatus and to allow the value of the leakage magnetic flux to fall within the above-mentioned recommended value.

Method and device for suppression of leakage of magnetic flux in display apparatus


A multi-lens apparatus for altering the mode field of an optical signal is disclosed. The apparatus includes an optical fiber having a core region defining an optical axis and a GRIN-fiber lens positioned in relation to one end of the optical fiber. A biconic lens including an external surface defined by two different curves disposed substantially orthogonal to one another, a major curve C1 and a minor curve C2, with C1 and C2 intersecting at or near the optical axis is positioned in relation to an end of the GRIN-fiber lens remote from the fiber. A method of manufacturing a multi-lens apparatus for altering the mode field of an optical signal, and an optical assembly are also disclosed.

1. Field of the Invention
The present invention relates generally to optical devices for mode-transforming interconnections, and more particularly, to a multi-lens mode-transforming apparatus configured to facilitate high efficiency coupling of optical signals passed between optical components and/or other waveguides having different mode fields.
While the present invention is subject to a wide range of applications, it is particularly well suited for coupling sources of elliptically-shaped optical signals, such as laser diodes and semiconductor waveguides, to optical fibers having circularly symmetric mode fields.
2. Technical Background
Coupling optical signals passed between signal sources, such as laser diodes, optical fibers, and Semiconductor Optical Amplifiers (SOAs), and other optical components, such as optical fibers, specialty fibers, SOAs and the like, with a high coupling efficiency, is an important aspect of optical communications. A conventional light-emitting module incorporated in an optical communications system generally includes a semiconductor laser, such as a laser diode, serving as a light source, an optical fiber having a light carrying core, and a lens such as a spherical lens, self-focusing lens or aspherical lens interposed between the semiconductor laser and optical fiber for converging the laser beam onto the optical fiber core. Since the light-emitting module typically requires high coupling efficiency between the semiconductor laser and the optical fiber, the module is preferably assembled with the optical axes of the semiconductor laser, lens, and optical fiber aligned with each other in order to achieve maximum coupling power. The relatively large size and high cost of early light-emitting modules, due in part to lens spacing and alignment issues, have driven advancement in the field and have resulted in a number of alternative approaches.
One such approach is the use of a graded-index (GRIN)-rod lens. Unlike other lenses, the index of refraction of a GRIN-rod lens is radially-dependent and is at a maximum at the optical axis of the rod lens. Generally speaking, the refractive index profile across a GRIN-rod lens is parabolic in shape, and thus it is the lens medium itself, rather than the air-lens interface, that performs the lensing. Accordingly, unlike conventional lenses, GRIN-rod lenses have planar input and output surfaces making refraction at these surfaces unnecessary. This characteristic enables optical elements at either end of the lens to be fixed in place with index-matching glue or epoxy. The index gradient is typically produced by an ion-exchange process that is both time-consuming and expensive. A typical GRIN-rod lens, for example, may be produced by ion-exchange of thallium or cesium-doped silica glass. A molten salt bath may be used for the ion-exchange process such that sodium and either thallium or cesium ions diffuse out of the glass, while potassium ions diffuse into the glass from a 500° C. KNO3 bath.
Since it is the refractive index profile of the lens medium resulting from this process that lenses the light, tight controls are required during the manufacturing process to ensure that a given GRIN-rod lens has the appropriate refractive index profile for a particular coupling application. Moreover, unlike GRIN-fiber lenses employed in accordance with the present invention, GRIN-rod lenses are poorly adapted for splicing to standard telecommunication fibers, and/or other optical components. Generally speaking, GRIN-rod lenses are multi-component glass structures that have significantly different coefficients of thermal expansion and softening points (the temperature at which the glass softens) than the optical waveguides to which they are coupled. GRIN-fiber lenses, on the other hand are typically made by a fiber manufacturing process and are high silica composition structures. Thus, the softening points and thermal expansion coefficients of GRIN-fiber lenses are substantially similar to the softening points and thermal expansion coefficients of most telecommunication fibers and other waveguides to which they may be attached. Accordingly, GRIN-fiber lenses are well adapted to be coupled, as for instance, by fusion splicing, to most telecommunications fibers.
Another approach has been to form a microlens on an end of an optical fiber to provide optical coupling between a semiconductor laser and an optical waveguide. In such an approach, the lens is directly and integrally formed on an end face of the optical fiber at a portion of the fiber on which light from the light source is incident. Such an optical fiber is hereafter referred to as a, "lensed optical fiber". When manufacturing light-emitting modules using such lensed optical fibers, the number of required component parts can be reduced since there is no need for light-converging lenses apart from the fiber itself, and since the number of operations associated with axial alignment may also be reduced. Lensed optical fibers are referred to as anamorphic lensed optical fiber when the lens formed on the end of the optical fiber is capable of changing the mode field of an optical signal passed therethrough. More specifically, an anamorphic lens formed on the end of the optical fiber is generally capable of changing the elliptical mode field of an optical signal emitted from a laser diode to a substantially circularly symmetric optical signal, which can be more efficiently coupled to the core of an optical fiber having a circularly symmetric mode field.
Each of the above-described approaches have various utilities and advantages that are well known in the art. Each approach does, however, have its own set of limitations. For example, while conventional GRIN-rod lens technology provides excellent symmetrical focusing characteristics for optical signals passed therethrough, GRIN-rod lenses alone generally do not significantly alter the geometric shape of an optical signal as is often required for efficient optical signal coupling applications. In addition, since it is the material characteristics of the GRIN-rod lens itself that provides the focusing, precise manufacturing techniques are necessary in order to provide controlled variation of the refractive index profile of the GRIN-rod lens needed for a particular application.
Likewise, while anamorphic fiber lenses readily facilitate the changing of the geometric shape of the optical signal or beam passing through them, the range of available working distances for anamorphic lens applications is somewhat limited. Accordingly, if suitable working distances are not available for particular applications, coupling losses may be significant, thereby making many coupling applications impractical.
What is needed therefore, but presently unavailable in the art, is a multi-lens apparatus for optical signal coupling applications that overcomes these and other shortcomings associated with the use of anamorphic lenses or GRIN-rod lenses alone. Such a multi-lens apparatus should be capable of changing the geometric shape and other mode field characteristics of an optical signal passing through the apparatus, while at the same time providing design flexibility that will limit coupling losses, allow a broader range of acceptable working distances, minimize phasefront aberrations, and generally provide greater control and efficiency in optical signal coupling applications. Such a multi-lens apparatus should be relatively inexpensive to manufacture, be relatively easy to mass produce, and in general, have a far broader range of applications without significantly altering the material properties and characteristics of the lenses themselves. It is to the provision of such a multi-lens device that the present invention is primarily directed.

Beam altering fiber lens device and method of manufacture


A method is performed in a control device for controlling a power compensation arrangement including a voltage source converter and one or more power compensation branches, each power compensation branch including a thyristor controlled reactor, a thyristor switched reactor or a thyristor controlled capacitor. The voltage source converter and the one or more power compensation branches are connected to a same busbar. The method includes: detecting a request in an electrical power system to which the power compensation arrangement is connected; determining, based on the request, a need for reactive power supply to the electrical power system; providing reactive power by means of the voltage source converter and/or by one or more of the power compensation branches; and compensating, by means of the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system. Corresponding devices are also disclosed.

Reactive power compensators are used for voltage control, reactive/active power flow control, transient and steady-state stabilization for improving the operation and functionality of e.g. electrical power transmission and distribution systems.
Thyristor Controlled Reactors (TCRs)/Thyristor Switched Reactors (TSRs) and Thyristor Switched Capacitors (TSCs) have been widely used as inductive and capacitive reactive power branches of Static Var Compensators (SVCs), respectively.
A drawback of the TCR is the amount of harmonics, e.g. 5th, 7th, 11th, 13th, . . . , etc. harmonics, that it generates during steady state operation and also, during unbalanced network voltage, harmonics of 3rd, 9th, . . . etc. order. For the TCR, harmonic filter branches are normally required in order to reduce the harmonic emission to reach performance levels specified by the network operator. Such filter branches are expensive and require large footprint, e.g. in a substation where they are typically placed.
The TSR does not generate low order harmonics, but a drawback of the TSR is that it creates large current transients in the feeding network when switched in or out, causing voltage disturbances. In order to minimize the voltage transients from the TSR, it is often necessary to divide the TSR in smaller sizes and/or use it together with TSC.
The TSC comprises capacitor banks requiring large footprint, and energizing transients of the capacitor banks have to be taken care of. In particular, energizing a second capacitor bank when a first capacitor bank is already energized, i.e. back-to-back switching, requires the frequency and amplitude of voltage oscillations on a busbar to be limited in order not to generate overvoltages.
Nowadays, it is a trend to replace these branches by Voltage Source Converter (VSC) based chain-link technology. The chain-link technology of the VSC is however rather costly to implement, mainly since it entails advanced power electronics switching devices and advanced control technology.
The various power compensation devices thus have their advantages as well as drawbacks and while high performance can be obtained, it comes with high costs, both initial costs and maintenance costs.

Methods and devices for power compensation


An ink jet printer comprising a plurality of ink jets arranged for dot-on-dot continuous ink jet printing, at least two of said plurality of ink jets being supplied with ink of the same dye and different densities. A printed article and a method of printing are also disclosed.

A great variety of ink jet printing technologies are known in the patent literature. Among these technologies is the use of inks of the same color but of different densities in multiple jets of an ink jet printer. The following U.S. Pat. Nos. are believed to represent the state of the art at the time that the present invention was made: 4,367,482; 4,494,128; 4,560,997; 4,604,654; 4,635,078; 4,672,432; 4,686,538; 4,695,846; 4,713,746; 4,714,964; 4,855,753; 4,860,026; 4,952,942; 4,963,882; 4,967,203; 4,999,646; 5,091,734; 5,111,302 and 5,142,374.
Dot on dot ink jet printing is known in the patent literature inter alia from U.S. Pat. Nos. 4,620,196 and 4,851,860.

Dot on dot ink jet printing using inks of differing densities


The present invention provides a display module (100; 200) and an electronic terminal. The display module (100; 200) comprises: a first display unit (130; 240) configured to display first image information in a first direction; a second display unit (140; 250) configured to display second image information in a second direction; and a sensor unit (150; 260) provided between the first display unit (130; 240) and the second display unit (140; 250) and configured to sense an object's approach or touch on the first display unit (130; 240) and/or the second display unit (140; 250). With the display module (100; 200), the object's approach or touch on the first display unit (130; 240) and the second display unit (140; 250) can be sensed by a single sensor unit (150; 260). There is no need to provide a sensor unit (150; 260) for each of the display units (130; 240; 140; 250) for touch sensing function. In this way, it is possible to reduce the thickness of the display module (100; 200), make it slimmer and more beautiful while reducing manufacture cost.

To enable a user to view a display from more than one view angle, display manufacturers have developed a double-sided display. That is, two one-sided display screens are combined in a back-to-back manner, such that different images can be displayed on the two opposite sides. Further, to use such display in a more convenient way, a touch sensing layer can be provided on each side of the double-sided display screen to enable touch function on each of the screens.
For a traditional touch screen, the touch sensing layer is typically provided on a surface of the screen. For a double-sided display, a touch sensing layer is required on each of the display screens. Due to the configuration of two display units and two touch sensing layers of the double-sided display, it is difficult to manufacture a thin and light display with good appearance and low cost.


The present invention addresses the problem of providing an absorbent article that is provided with a liquid-permeable layer, said liquid-permeable layer having convex portions that are hollow inside, has an improved ability to transfer menstrual blood from the liquid-permeable layer to an absorbent body and can reduce the amount of the menstrual blood remaining in the liquid-permeable layer (in particular, the internal cavities in the convex portions). To solve this problem, provided is a sanitary napkin provided with a liquid-permeable top sheet, a liquid-impermeable back sheet and an absorbent body that is interposed between the top sheet and the back sheet, wherein convex portions, said convex portions being hollow inside and formed in an excretion orifice contact region of the top sheet, are coated with a blood lubricity-imparting agent that has a kinetic viscosity of 0.01-80 mm2/s at 40° C., a water retention rate of 0.01-4.0 mass % and a weight-average molecular weight of less than 1,000.

As top sheets for absorbent articles there are known top sheets having concavoconvexities formed therein by gear stretching (PTLs 1 and 2).
The top sheets described in PTLs 1 and 2 each have a first layer provided on the skin contact side and a second layer provided on the non-skin contact side, the first layer having internally hollow projections bulging out on the skin contact side, and being partially bonded with the second layer at the sections other than the projections.

This patent is subject to a terminal disclaimer.

Absorbent article with blood slipping agent


A method of selecting interconnection products using a computer-based interconnection selection tool, the method comprising: (a) providing an image to a user, the image depicting multiple interconnections, each interconnection having a referenced interconnection level; (b) receiving a selected interconnection level of interest; (c) providing at least one interconnection prompt corresponding to a given interconnection level of interest; (d) receiving at least one response to the interconnection prompt; (e) providing interconnection options responsive to the at least one response; (f) receiving at least one product selection from the interconnection options and storing the product selection to a list; (g) optionally reiterating steps (c)-(g) until a prompt is provided in step (c) for each level of a group of interconnection levels or the user terminates the process; and (h) after step (g) or the user terminates the process, providing the list to the user.

Electrical and optical interconnections are critical to essentially all electronic devices, machines, and telecommunications. Interconnections relate to a variety of different interface connections, including, for example, circuit board to circuit board connections, component to circuit board connections, cable connections between circuit boards, and sub-assemblies to sub-assemblies, just to name a few. Indeed, in essentially every electrical or optical system, there are many different levels of interconnect that have to be selected to optimize the performance of the system.
Selecting the right interconnect is becoming more and more challenging. First, the number of applications requiring such interconnects have exponentially increased in recent years. And the number of available interconnects have likewise increased. Thus, at this time, it is essentially impossible for anyone to know the all of the available interconnect options to easily determine the optimum interconnect for a given application. Rather, salespeople and users typically rely on past experience and their own knowledge of available interconnect to select the most appropriate interconnect for a particular application. Obviously, given that no one person can recall all of the available interconnect options, such an approach is unlikely to optimize the interconnect selection. Complicating matters, in a typical sales situation, an interconnect selection needs to be made quickly, so often there is insufficient time to flip through pages of catalogs to determine the right interconnect. The current approach, is to use an e-catalog where products are presented in an electronic format on the user's computer. Such an e-catalog is beneficial in that it allows users to browse interconnect solutions critically and facilitates the electronic capture of desired interconnects, it still lacks the ability to guide the user to the optimal solution.
Failing to optimize interconnect selection not only undermines the credibility of the salesperson or user, but also reflects poorly on the particular interconnect used in less than optimum conditions.
Therefore, there is a need for an interconnect selection approach that is intuitive and leads to a determination of the optimum interconnect for a given application. The present invention fulfills this need among others.

System and method for selecting interconnects


A valuables-holding device in the form of a booklet which appears, when closed, to be an ordinary compositional notebook or pocket diary has a flange or transparent overlay extending around three sides of the inside front cover. A flexible covering plate, with its edge secured to the spine of the booklet, has its free edge capable of being slid behind the overlay. This will cover the space between the back of the covering plate and the inside surface of the front cover of the booklet. The covering plate can be slid out of the overlay, too, to expose that space. Secured to the inside of the front cover is a credit card organizer. The front cover and the covering plate are both preferably formed with a thin sheet of metal. Thus, the space between those components is electronically sealed or blocked from an RFID reader. The covering plate includes a slot for sliding paper money therethrough and into the space between the back of the credit card organizer and the inside surface of the front cover.

The present invention relates to a camouflaged and valuables-protecting wallet, in the form of a book or booklet, like a pocket diary or small compositional notebook. The basic device comprises a pair of outside covers and a set of paper sheets therebetween. The user's valuables, primarily consisting of credit cards and paper money can be concealed in an area or pocket/compartment located between either or both of the outer covers of the book and a thin movable cover plate adjacent thereto. The movable (it turns like a page turns, extending from the spine of the booklet) cover plate can slide into and out of a set of plastic flanges or overlays which extend inwardly (with respect to the cover's edges) and on the inside of the top, bottom, and outside (as opposed to the spine) edge of the cover(s). When the movable plate has its free edges slid beneath the flanges or overlays, the area behind the front (and/or rear) cover and the adjacent covering plate serves as a holding area for paper money and/or an organizer for one or more vertically stacked and staggered credit cards. When the covering plate or sheet is rolled or slid out or removed from the overlays/flanges, and turned as a page of the booklet, the paper money and credit card holder (staggering the top edges of the credit cards in a standard manner) are easily accessible. And, as mentioned, the present invention is intended to have one or more of the covers and/or covering plate(s) formed of a thin metallic layer or sheet to protect the data on the magnetic strips of the credit cards from being read by an RFID reader.
The thrust of the device and its function is to deceive and thereby prevent thieves and others from finding or recognizing a valuables-containing wallet, thereby deterring theft of precious materials, e.g., driver's license, credit cards, and paper money. Theft is a common problem and one that can be encountered anytime or anywhere. It can sometimes happen when a person's possessions are left unattended or unwatched. In that case, a thief is likely to dig through a purse or bag or other possessions looking for a conventional wallet to find money, credit cards, or sellable identifying information. Theft cannot be avoided simply by attending to one's possessions though. Thieves are also known to physically stop individuals and demand money or a wallet, often threatening violence if the victim does not comply, or simply taking objects directly off of the owner as is the case with pickpockets.
Even further, documents such as passports and credit cards that contain magnetic and readable strips or RFID strips or tags pose the risk of being discretely and unlawfully scanned without the owner's knowledge and the information contained therein then being used, stolen, sold quickly and then improperly used. When a thief having an electronic scanner (an RFID reader) is in the proximity of the credit cards or magnetically encoded strips on documents, he can scan the card or document's magnetic strip without having physical possession or access to the actual card or document. In that scenario, an unsavory individual nearby can scan and steal information without the owner even being aware. He can then use or sell the same. However, if the magnetic strips (with the data) are housed or covered within or between thin layers of metal, the RFID reader is blocked. From a security perspective, this is highly desirable.
Various articles have been developed to combat the threat of theft, including wallets which secure tightly against a user's body underneath clothing, pockets within waist belts for holding valuables, wallets that are chained to a belt, wallets requiring keys, and electronic passwords and signatures for opening of the same. However, many of these articles make it difficult for even the owner to reach his valuables within the wallet. Other developments, such as electronic passcodes, can be worked around in time. The present invention is a conventional-looking pocket diary or booklet with hidden areas for holding credit cards and paper money, all with metal sheets protecting against improper RFID reading of the data on the same.
There remains a need for a simple wallet or valuables-carrying device that visually presents as another object and that defends against electronic scanning while still being easy to carry, access, and use. The present invention conceals a wallet or pocket/compartment(s) within a diary, a notebook, a composition looking notebook, i.e., a pad of paper meant to look like a personal calendar, diary or journal, which appears to be of no use to anyone but the owner himself. The notebook further has one or more metal plates sandwiching the credit cards or the front and back covers are metal sheet lined to prevent digital scanning of the materials contained within the interior holding compartments, as well. In an alternate embodiment, the device resembles an ordinary pocket diary, calendar, a thin notebook, etc. with many sheets of ordinary writing paper secured to the spine. The covers (front and rear) are formed with thin, metallic sheets (preferably copper, aluminum, silver and/or gold or alloys thereof). On the inside of the front and rear covers, spaced from the front and rear covers, can be a second layer of thin, metallic material. This covering page or plate will be alternatively held within a set of contiguous overlays of the covers of the booklet or removed from the flanges or overlays to expose the credit card organizer and pocket money holding areas. Between the covering plate and the inside surface of the outer covers of the booklet, a holding pocket (actually two such pockets—one at the front, one at the rear of the booklet) for an organizing, stacking rack of credit cards and paper money space/compartments can be provided. The overlays or flanges are preferably thin, transparent and plastic, more preferably they are a continuous three sided, inwardly directed border of the inside surface of the front and rear covers, all to selectively capture and release the edges of the covering plate.
A camouflaging booklet for valuables which also protects the same from RFID readers is a goal sought to be provided by the present invention. It is desirable to have the same lightweight, inexpensive, attractive and functional.

Compositional notebook/diary with concealed pocket for valuables


Provided are a pass gate circuit and a method of controlling the same for improving meta-stability when transferring signals. The gate circuit includes a signal transfer unit transferring an input signal in response to a transfer control signal, and a control signal generating unit generating a safety window having a predetermined width in response to detection of a transition of the input signal, generating an internal control signal for maintaining the signal transfer state of the signal transfer unit, and outputting the internal control signal to the signal transfer unit as the transfer control signal.

1. Field of the Invention
The present invention relates to a pass gate circuit and a method of controlling same. More particularly, the invention relates to a pass gate circuit and a related control method that provide improved meta-stability during signal transfer.
2. Description of the Related Art
So-called pass gate circuits are commonly used in the circuits forming semiconductor memory device. In this context, many pass gate circuits are used to facilitate switching operations. For example, a pass gate circuit may be used to implement a latched data output circuit in a semiconductor memory device. Pass gate circuits are turned ON/OFF in response to a control signal. When turned ON, a pass gate circuit will receive and output an input signal. When turned OFF, the output of the received input signal by the pass gate circuit is disabled.
Figure (FIG.) 1 is a circuit diagram of a conventional pass gate circuit 10. Referring to FIG. 1, pass gate circuit 10 includes a transfer controller 11 and a latch 12. Transfer controller 11 includes a pass gate PG implemented with a Complementary Metal Oxide Semiconductor (CMOS) element configured with at least one inverter. Latch 12 includes at least one inverter to latch a received signal until it is output. An initial input signal "A" is the input signal to be transferred through pass gate circuit 10. An external control signal "B" is applied as a control signal to the control electrode of pass gate PG. Thus, control signal B controls the transfer of input signal A through pass gate circuit 10. Furthermore, signal C is the output signal of pass gate circuit 10.
Unfortunately, conventional pass gate circuit 10 can operate in an unstable mode when input signal A and control signal B simultaneously transition from one logic level to another. During unstable operation, the output signal from pass gate circuit 10 becomes unstable such that its amplitude decreases to thereby cause a meta-stability problem.
FIG. 2 is a waveform diagram illustrating an unstable signal transfer by pass gate circuit 10. Referring to FIG. 2, input signal A and control signal B simultaneously transition from a logically high level (hereafter "high") to a logically low level (hereafter "low"). When control signal B transitions to low, the pass gate PG is turned OFF and current cannot be supplied to the input terminal of pass gate circuit 10, and the output of the pass gate PG becomes unstable.
Output signal C from pass gate circuit 10 varies in relation to input signal A. Pass gate circuit 10 operates normally when input signal A transitions outside the period when control signal B transitions. However, when input signal A and control signal B transition simultaneously, output signal C follows input signal A after a predetermined delay time. As a result, and as illustrated in FIG. 2, a completely different output signal waveform is obtained over that which is intended under normal operation of pass gate circuit 10.

Pass gate circuit stably transferring signal and control method


A method and a control apparatus for driving a lamp 14 in a lighting system, in particular a lamp having a fast response to a change of an amount of energy supplied through the lamp, in which a device controller 8 is connected with the lamp 14. The device controller 8 receives data values from a system controller 2 to change a light output level of the lamp 14. Upon receiving a data value which is different from a previously received data value the device controller calculates additional data values and distribute the additional data values in a following time interval to smoothen a transition between different light output levels of the lamp 14.

A method of said type is known from practice. In particular such a method is known for driving an incandescent lamp, in which the driver comprises a triac, which is connected in series with the lamp and an alternating voltage source. The triac is controlled by a control signal which determines a phase of each period of the alternating voltage at which the triac is made conductive. If a current through the triac decreases below some threshold the triac will stop conducting. This type of driver is well known from its use in homes.
For some years now it is a trend to control its state, that is the amount of energy supplied to it, from a remote controller. Several lamp devices can be connected to such remote controller by a data communication line and to a mains supply source by mains lines. The remote controller can control the state of the lamps contained in on or more lamp devices. In this way one can build a large lighting system with remote control of lamps of different lamp devices with few wiring for control and mains supply.
Light systems of the above type are known from practice. Several protocols, such as DMX and DALI, are known to transfer data from the remote controller to a device controller of each lamp device. In particular, data to control the energy state of a lamp comprises 8 bits. Therefore a light output of a lamp can be controlled in 255 steps to 256 different light output levels of the lamp. Such data can be determined by a lighting scheme which is programmed in the remote controller, or it can be instructed from a manually controllable control device at a distant from the remote controller mentioned above.
When the amount of energy supplied to an incandescent lamp is changed it will take some time to attain a new steady temperature which is associated with the changed amount of energy supplied to the lamp. Therefore, when changing said amount of energy a person will not notice a step like change in the light output of the lamp.
When using a lamp with a faster response to a change of the amount of energy supplied to the lamp a person may notice a step like change in the light output of the lamp, in particular if said change of the amount of energy supplied to the lamp spans several of said 255 steps at a time. This can be annoying for the person.

Method for driving a lamp in a lighting system based on a goal energizing level of the lamp and a control apparatus therefor


An optical receptacle includes an optical component assembly, a tubular sleeve, and a tubular shell. The optical component assembly includes a light guide member, a tubular member, which retains the light guide member in the through hole, and projections, which extends outward of an outer peripheral surface of the tubular member at one end. The sleeve is fitted to the outer periphery of the light guide member at a rear end portion. The inside diameter of a front portion of the sleeve differs from that of the rear end portion. The shell covers the outer peripheral surface of the sleeve and includes a groove in a rear end portion. The groove extends in an axial direction and turns and extends in a circumferential direction. The groove is engaged with the projections of the tubular member to secure the shell. The shell and the sleeve are attachable and detachable.

Optical communications transceiver modules are used in two-way communication over optical fiber. The optical communications transceiver module includes, in a small package, an optical transceiver circuit including a light emitting element, such as a laser diode (LD), or a light receiving element, such as a photodiode (PD). Also, the optical communications transceiver module includes an optical receptacle portion attached to a case of the small package. An optical fiber can be coupled to the optical receptacle portion to enable communication with an optical communications transceiver module at the other party.
A conventional optical communications transceiver module includes an optical receptacle portion and an optical element device portion.
The optical element device portion contains an optical element, e.g., a light emitting element such as an LD or a light receiving element such as a PD. The optical element device portion is secured to a holder of the optical receptacle portion via an adapter.
The optical receptacle portion includes the holder, a fiber stub, a sleeve, and a sleeve cover. In the fiber stub, an optical fiber is inserted along the central axis. The sleeve has a cylindrical shape and is attached to cover the front end of the fiber stub. The holder holds the fiber stub inside and holds the outer peripheral surface of the sleeve cover at a lower portion thereof. The sleeve cover is secured to the holder by press-fitting or by adhesive bonding so as to cover the sleeve. The sleeve cover is also referred to as a shell.
An optical connector can be coupled to the optical receptacle portion in such a manner that a plug ferrule within the optical connector is guided by the sleeve to bring the end surface of the ferrule and the end surface of the fiber stub into contact with each other while being aligned along the central axis. This brings the optical fiber within the ferrule and the optical fiber within the fiber stub into contact with each other to couple the optical signals.
The sleeve cover 114 of the optical receptacle portion is made of a non-metallic material, e.g., zirconia ceramic material. Other materials often used for the sleeve cover include metal materials such as special use stainless steel (SUS). The sleeve cover is secured by being press-fitted, at a lower portion thereof, to the holder. Some sleeve covers are designed to be secured to the holder by an adhesive. However, in view of tightness of securement, and because of consistency of the tight securement obtained, for example, the technique of securing the sleeve cover to the holder by pressfitting is often employed.
The optical receptacle portion, the sleeve cover is made of a non-metallic material, and therefore the sleeve cover will not act as a noise antenna.

Optical receptacle, optical communications transceiver module, and method for producing optical receptacle


A non-transitory computer readable medium, storing a program causing a computer to execute a process for causing at least portions off display screens of plural terminals connected to each other through a network to display information in a synchronous manner, includes receiving material information indicating information regarding a material to be displayed, receiving operation information indicating details of operations that users perform on the respective terminals, and recording minutes information in which the material information, the operation information, and time information indicating times at which the users perform the operations are associated with each other.

(i) Technical Field
The present invention relates to a non-transitory computer readable medium, an information processing apparatus, and an information processing system, and.
(ii) Related Art
In recent years, so-called electronic conference systems, in which a PC, a tablet terminal, and the like are connected to each other through a network to electronically share materials, sound, video data, and the like, have been used. In such an electronic conference system, there has been proposed a technique for recording multimedia information (multimedia data) such as sound exchanged during a conference or a video obtained by capturing the state of the conference, for the purpose of mainly creating minutes of the conference, and the like. However, the recording of the intact multimedia data may result in that the amount of data of the minutes becomes huge.

Non-transitory computer readable medium, information processing apparatus, and information processing system for recording minutes information


To maintain tension on a fiber tow as it travels between a spool of the tow and a fiber placement head in a computer controlled fiber placement machine, closed tension loop servo control tow velocity feed forward is provided to control spool rotation so as to not only provide closed loop tension control but to also cause rotation in anticipation of expected tow movement such as due to tow payout upon commanded movements of the fiber placement head. Gain scheduling based on spool radius is also provided. Additionally, a compliant roller is provided to reduce tension dips and spikes from disturbances on the tow, and an inner velocity loop is included with the closed tension loop to provide more effective control of tow tension. The servo control is reconfigurable into an open or pseudo-closed loop mode with a safety low power supply to slowly reel-up slack tow after tow threading, for example, and to otherwise maintain low tension on the tow to hold it in the machine while allowing servicing thereof. A broken tow test is also provided to detect tow slippage indicative of tow breakage or a possible part defect.

I. Field of the Invention
The present invention relates to computer controlled fiber placement machines which apply bands of fiber tows to a mandrel or the like to construct components made up of the fiber tow material. More particularly, the present invention relates to controlling the tension on the fiber tows in the active application mode of operation of such machines as well as to control tow take-back to avoid snap-back after rethreading a tow.
II. Description of Prior Art
By way of background, a computer controlled fiber placement machine includes a creel assembly which feeds a band of individual fiber tows under tension to a tool such as a fiber placement head. Each fiber tow is typically provided from a respective spool mounted for rotation on a motor driven chuck on the creel assembly. Each tow is individually threaded from the chuck-mounted spool and through a guidance structure such as over various rollers and on to the fiber placement head. After each tow is threaded, any slack in the tow must be taken up to place the tow under tension for proper application by the fiber placement head.
The fiber placement head is mounted to a robot wrist, for example, and is thus movable under program control through a wide variety of spatial orientations. As the fiber placement head moves about, one or more of the fiber tows are to be applied to either a stationary or rotatable mandrel, for example, to construct a component such as an air foil. Where the mandrel is rotatable, it too may be under program control. During application of the fiber tows to the mandrel, it is desired to maintain the tows under tension between say 1 to 10 lbs. However, the desired or necessary tension may vary as a function of speed of application such as caused by rotation of the mandrel and/or movement of the tow by the fiber placement head, for example. To this end, it has been proposed to provide a computer driven servo-control tensioner by which to control tension under program control as the tows are being applied, i.e., in the active application mode of the machine.
More specifically, it has been proposed to provide a closed-loop microprocessor based servo-controlled tensioner which accepts programmed tension setpoints from a computer numerical control (CNC) controlling the overall machine, and to vary the signals to the motor driven chuck in an effort to achieve and maintain the commanded tension setpoint. As will be appreciated, users of computer controlled fiber placement machines typically program the CNC in so-called world coordinates which define selected points of tow application relative the frame of the machine, such as at the centerpoint of the robot wrist supporting the fiber placement head. The user may also pre-program tension setpoints at these selected points or world coordinates. The CNC manipulates the world coordinate inputs to divide them into a plurality of incremental tool paths between each pair of world coordinates input by the user so as to define a plurality of incremental moves of the various parts of the machine by which to cause the fiber tows to be applied between the world coordinate pairs. At each new world coordinate, the CNC provides the programmed tension setpoint (if different from the prior tension setpoint) to the tensioner microprocessor to define the tension which is to be maintained for each incremental move of the machine parts to the next world coordinate. To this end, the tension setpoints from the CNC may be utilized by the tensioner microprocessor in a feedback loop which compares actual tension on the tow and the commanded tension setpoint to generate a tension error signal. Typically, the feedback loop also includes a filter to compensate for known characteristics of the tensioner such that the tension error signal is modified in a predetermined manner such as by proportional, integral and/or derivative functions as is well known. The filtered tension error signal is coupled to the chuck motor and causes the motor to tend to rotate in a direction which would either reel-off or spool-up the tow so as to decrease or increase tow tension, respectively, in an effort to achieve and maintain the commanded tension.
Experience has shown, however, that undesirable fluctuations in actual tension may still be encountered with such a closed-loop servo-control system. For example, the tensioner system must be able to maintain a tension setpoint as low as 1/2 pound on the tow even while the tow experiences acceleration or other disturbances on the tow. Because low tension setpoints may thus be involved, the allowable tension error is necessarily extremely small such as less than 1/4 pound. However, a variety of disturbances have been encountered in operating the tensioner system which can cause large dips and spikes in the tension making it difficult to maintain tension control. Such dips and spikes may occur not only from acceleration of the tow but also from mechanisms used in the machine which strike the tow or when the tow snaps-off of the spool such as tends to occur with tacky fiber tows or tow pregs as the tow pays off of the spool. On the other hand, the tensioner system must also be able to maintain much larger tensions on the tow, for example, upwards of 15 pounds. Yet, tension control is to be accomplished independent of the type of composite tow material and size or weight of the spool or the material. Accordingly, improvements to closed loop tension servo-controls are believed necessary.
Additionally, whenever a new spool is to be placed on the creel assembly, or a fiber tow breaks, it may be necessary to thread the tow from the chuck-mounted spool, through the rollers of the guidance structure, and into the fiber placement head. This threading process is normally accomplished with the tensioner disabled and by an operator manually pulling off lengths of tow from the spool and threading the loose tow through and around the appropriate rollers. As the operator pulls off lengths of tow, however, there may be a tendency for too much of the tow to reel-off. After the tow is threaded, control of the tensioner is to be restored to the CNC whereupon tow take-back may occur to tighten up the tow and place it under tension. As the CNC program is predefined without knowledge of the amount of reel-off, upon restoring control to the CNC, there may be a sudden and undesirable snapping action on the loose tow as the active servo-controlled drive seeks to restore the tension by respooling the tow. Accordingly, improvements to the tensioner are desired to reduce snap-back as the active application mode is restored and on tow take-back.

Intelligent servo-controlled fiber placement machine tensioner


In one aspect, the present invention relates to a method of making multi-phase particles that include nanoparticulates and matrix, which maintains the nanoparticulates in a dispersed state. A flowing gas dispersion is generated that includes droplets of a precursor medium dispersed in a gas phase. The precursor medium contains liquid vehicle and at least a first precursor to a first material and a second precursor to a second material. The multi-phase particles are formed from the gas dispersion by removing at least a portion of the liquid vehicle from the droplets of precursor medium. The nanoparticulates in the multi-phase particles include the first material and the matrix in the multi-phase particles includes the second material.

Nanoparticulate materials, and methods for making nanoparticulate materials, have been the subject of recent interest and research because of the advantages provided by nanoparticulate materials over larger sized particulate materials. One advantage of nanoparticulates is increased surface area, which is useful in a variety of applications, including catalyst, electrocatalyst, absorbent, chemical separations and bio-separation applications. Nanoparticulates are also useful in formulations of inks, pastes and tapes that are used in depositing thin or thick films, such as optically transparent conductors for use in displays, magnetic coatings for storage media and printed circuitry for electronic applications. Inks and pastes with nanoparticulates have improved rheology characteristics (e.g., flowability), which allow thinner layers to be applied and allow deposition of features with smaller dimensions. Lighting applications also benefit from the properties of nanoparticulate materials; for example, semiconductor nanoparticulates, in addition to other uses, are useful because of their "quantum dot effect," which allows the luminescent color of a semiconductor nanoparticulate to be tailored according to the size of the nanoparticulate. In addition to the examples above, nanoparticulate materials are being used, or considered for use, in many other applications including pharmaceutical formulations, drug delivery applications, medial diagnostic aids, abrasives, pigments, phosphors for lighting, dental glasses, polymeric fillers, thermal interface materials and cosmetics.
As a result of the large number of applications for nanoparticulate materials, a variety of methods have been developed for making and processing nanoparticulates. One common problem faced by these methods is the tendency of the nanoparticulates to agglomerate because of their high surface area. Once the nanoparticulates have agglomerated, often they do not provide the same advantages achieved when the individual nanoparticulates are in a dispersed state. Consequently, the tendency of nanoparticulates to agglomerate makes the forming, processing, handling, transporting and use of nanoparticulates problematic. Complicating matters is that separating or redispersing nanoparticulates once they have agglomerated is difficult to do.
Thus, there is a need for additional methods of forming, processing, handling, transporting and using nanoparticulates and new nanoparticulate products that alleviate some or all of these problems.

Gas dispersion manufacture of nanoparticulates, and nanoparticulate-containing products and processing thereof


An artificial intraocular lens assembly adapted for placement within the anterior or posterior chamber of the eye and for permanent attachment to the iris through natural ingrowth of living tissue, is disclosed. The lens assembly comprises a light refracting lens body and at least one lens support member which includes a portion having a surface contoured for intimate contact with the iris. A plurality of apertures are provided in the portion of the lens support member. After initial surgical affixation of the lens assembly within the eye, tissue of the iris grows into and through the apertures thereby anchoring the lens assembly within the eye.

1. Field of the Invention
The present invention relates to an intraocular lens assembly, and more particularly to an improved posterior chamber intraocular lens assembly which, after surgical affixation within the eye, is further anchored in the eye by natural ingrowth of a tissue of the iris of the eye.
2. Description of the Prior Art
The prior art is well aware of artificial intraocular lens assemblies which are surgically introduced into the human eye to replace the natural lens of the eye. One of the common reasons for removing the natural lens of a patient is a condition of lenticular disease known as a cataract. The prior art has developed a large variety of lens assemblies for surgical implantation either in the anterior chamber or attached to the iris of the eye.
Generally speaking, anterior chamber lenses of the prior art are placed between the iris and the cornea, and rely upon a precise size measurement to wedge the lens into a permanent position. The implantation of some of the artificial intraocular lens assemblies requires surgical incision or suturing to the iris. Other lens assemblies are kept in an operative position within the eye by a plurality of loops which embrace the iris and therefore "clip" the lens assembly to the iris. A recent posterior chamber lens, the SHEARING lens, is held in a relatively fixed operative position by spring like properties of a number of strands composed of plastic material, see U.S. Pat. No. 4,159,546.
For further detailed description of specific intraocular lens assemblies, reference is made to the following U.S. Pat. Nos. 3,925,825; 3,922,728; 3,971,073; 3,673,616; 3,913,148; 3,906,551; 3,994,027; 3,866,249; 3,986,214 and 3,991,426.
Although the implantation of artificial intraocular lens assemblies have become accepted by the medical profession, the artificial intraocular lens assemblies of the prior art can suffer from certain disadvantages such as dislodgment from their initial operative position as a result of post operative movement of the patient's eye.
It is readily appreciated by those skilled in the art, that in order to obtain optimal results a compromise must be found between the relative strength of affixation of the lens to the eye which could become a source of undue irritation, or tissue errosion and the necessity to keep the lens in an operative position within the eye.
U.S. Pat. No. 4,073,015 describes an intraocular lens mounting system wherein a plurality of loops extend substantially laterally from a light refracting lens body. Fibrous material is attached to the outer edges of the loops in areas where the edges come into contact with the iris. The loops affix the lens to the iris, and the subsequent ingrowth of the tissue of the iris further anchors the loops to the iris. U.S. Pat. No. 3,458,870 describes a corneal lens implant wherein a holding member for the optical lens is surgically implanted into the cornea. The holding member has a plurality of holes into which the ingrowth of the corneal stroma is purported to occur to further anchor the corneal implant to the cornea.
The improved artificial lens assembly mountings of the present invention which may be utilized in anterior chamber as well as in posterior chamber lens assemblies represent a further significant advancement.

Intraocular lens assembly with improved mounting to the iris


A system for controlling the temperature of the printing elements of a thermal printhead. The printhead is provided with a plurality of spaced apart temperature sensor that measure the temperature at various locations on the printhead. A processor receiving outputs from the sensors determines the approximate temperature of each printing element based upon its proximity to at least one temperature sensor and the temperature sensor outputs. The processor then uses the approximate temperature of the printing elements to formulate either a strobe signal or a serial data stream that is applied to the respective printing element. Each printing element thus receives a quantity of energy that is a function of whether the printing element will contribute to the printing of an image during a scan line as well as the approximate temperature of the printing element.

Thermal printers are commonly used to print alphanumeric characters and bar codes on a variety of printing media such as paper, label stock, tubing, etc. Thermal printers utilize a thermal printhead having formed therein a large number of thermal printing elements generally arranged in a row. The thermal printing elements are selectively heated to apply appropriate markings to the printing media, either directly or through a meltable transfer medium.
A thermal printhead can provide high-quality printing only if there is precise control of the temperature of the printing elements on the printhead. However, it can be difficult to precisely control the temperature of the printing elements because their temperature is not solely under the control of heating signals applied to the individual printing elements. Instead, the temperature of a printing element at any point in time is determined also by the energization history of the heating element as well as the current and past energization history of adjacent printing elements. In other words, for a given power of heating signal applied to a printing element, the temperature of the printing element will be higher if the printing element was energized during previous scans of the printhead and/or the adjacent printing elements are currently being energized or were energized during previous scan periods.
There have been several approaches that have been used to control the temperature of thermal printing elements. In the past, a single temperature sensor, such as a thermistor, has been used to provide an indication of the temperature of the entire printhead. However, thermistors sensing the temperature of the entire printhead at a single location are relatively slow to respond to rapid increases in the temperature of individual printing elements. The thermal feedback provided by this technique is thus too slow to precisely control the temperature of the printing elements. Also, feedback indicative of the overall temperature of the printhead is incapable of substantially assisting in the temperature control of individual printing elements. For example, if all of the printing elements on the right-hand side of a printhead are being energized while none of the thermal elements on the left-hand side of the printhead are being energized, the temperature of the right-hand side of the printhead will be significantly greater than the temperature of the left-hand side of the printhead. However, thermal feedback from a single temperature sensor is incapable of causing the control circuit to treat one side of the printhead differently from the other side of the printhead. In short, while a single temperature sensor may be helpful in providing long-term feedback of the overall temperature of the printhead, it is incapable of providing short-term feedback and feedback responding to the temperature variation between individual printing elements.
Another approach to controlling the temperature of thermal printing elements has been to record the energization history of the printing elements and use that history to control the energization of each printing element during each scan of the printhead. For example, whether a printing element was energized during each of the previous six scans of the printhead can be recorded, and the degree of energization of the printing element during the next scan of the printhead can be adjusted accordingly. Similarly, the present or past energization state of adjacent printing elements can be recorded and used to adjust the magnitude of energy applied to the printing element during the next scan of the printhead. If a given printing element was energized during previous printhead scans, or if the adjacent printing elements are energized during the present printhead scan or they were energized during previous printhead scans, then the energy applied to the printing element is reduced. Conversely, if the printing element was not energized during prior printhead scans and the adjacent printing elements were not energized during the current or previous printhead scans, then the energy applied to the printing element is increased. The use of a printing element history to control the energy applied to printing elements during a printhead scan markedly improves the control of printing element temperature. However, this energization history technique essentially provides only very short term feedback (i.e., on the order of several printhead scan times). The energization history technique can be combined with the above-described single temperature sensor technique to provide both very short-term feedback and very long-term feedback. However, even this approach does not provide optimum temperature control of printing elements because there is a relatively long period of time during which there is no thermal feedback. In other words, the energization history technique provides thermal feedback for the last several printhead scans while the single temperature sensor technique provides thermal feedback for relatively long periods of time covering a large number of printhead scans, but there is no thermal feedback covering the period between several printhead scans and a large number of printhead scans. As a result, it is very difficult to precisely control the temperature of printing elements using the above-described techniques.

Method and apparatus for controlling a thermal printhead