A method of producing a photosensitive microcapsule which contains a polymerizable monomer and a polymerization initiator. Soluble water is displaced in the polymerizable monomer by performing one or both of distilling the polymerizable monomer and adding a dehydrating agent to the polymerizable monomer. The polymerization initiator and a first microcapsule-forming material are added to the water-displaced polymerizable monomer to produce a solution. Soluble oxygen in the polymerizable monomer is displaced by performing one or both of bubbling an inert gas and adding an oxygen absorbent to the polymerizable monomer. Soluble oxygen may also be displaced in an ionic surfactant by performing the bubbling and adding of oxygen absorbent. The ionic absorbent is added to the solution containing the polymerizable monomer and polymerization initiator, and then the solution is emulsified. A microcapsule membrane is produced by adding a second microcapsule-forming material to the emulsion.

The present invention relates to a photoimaging and thermal development recording media utilizing microcapsules.
Examples of a photoimaging recording media utilizing microcapsules include U.S. Pat. Nos. 4,529,681 (Usami et al.), 4,916,042 (Sakojiri et al.), 4,440,846 (Sanders et al.), 4,339,209 (Sanders et al.), and U.S. patent application Ser. No. 407,406 (Sakojiri et al.) filed on Sep. 14, 1989.
Those recording media utilize photoimaging forming materials such as a polymerizable monomer, photopolymerization initiator, and/or dye precursor etc. contained in the microcapsules as the main compounds. When a recording sheet (such as a plastic film) is coated with the microcapsules and image-wise exposed with light, the exposed portion of the microcapsules harden. Pressure or heat is applied to the unexposed portion of the microcapsules to emit the compounds contained in the microcapsules to form an image.
However, the conventional photopolymerization initiator is mainly a water soluble pigment and suffers from serious drawbacks. The water soluble pigment is easily diffused into a water phase which causes difficult emulsification while the microcapsules are produced. Consequently, the obtained microcapsules are not evenly photosensitized. At the worst, some conventionally produced microcapsules remain unhardened even if exposed.
In particular, monomer polymerization requiring light energy does not produce a sufficiently strong polymer because the photopolymerization initiator is inactivated by water. The grown-polymer-radical and water react with each other, and the polymerization reaction is stopped and a polymer of a low molecular weight is produced. If this sort of polymerizable monomer is contained in the microcapsules, the contained water in the polymerizable monomer increases during the process of microencapsulation. This contained water impedes the photopolymerization reaction, and the exposure of the light energy does not enable a sufficient hardening of the microcapsules thus lowering the microcapsule photosensitivity.
Further, a nonionic surfactant such as polyvinyl alcohol (PVA), polyethyleneglycol (PEG), and solitan derivative are conventionally used as the surfactant for producing the microcapsules.
The microcapsules including the polymerizable monomer are compounded with the nonionic surfactant, however, polymerization reaction, such as radial polymerization, is impeded by the invasion of water in the microcapsules through the process of microcapsulation. Accordingly, the conventional microcapsule polymerization process still results in low-weight molecules, or the polymerization process does not produce any reaction at all, and thus the internal part of the microcapsules does not harden completely.
If the polymerizable monomer which is the content of the microcapsules includes abundant oxygen, various problems result such as a sufficiently strong polymer cannot be produced because the polymerization initiator is inactivated by the oxygen, the grown-polymer-radical reacts with the oxygen, and a low polymer is produced.

Method of producing photosensitive microcapsules


A manifold for a front-discharge fluid end reciprocating pump. The manifold comprises tubular portions which are connected to ports on the pump by threaded engagement of a plurality of nuts. The manifold has a center portion and at least one branch portion which intersects the center portion. Another tubular portion having a ported end is in communication with the center and branch portions and provides an outlet for the manifold. At least one nut on the manifold is a standard nut having lugs extending therefrom adjacent to an outer surface of the nut. A special nut is used on at least one of the connections and has lugs extending adjacent to the inner surface thereof. The lugs on the special nut have a longitudinal thickness less than the nuts on the standard nut. In this way, the nuts may be engaged with closely adjacent ports on the pump without interference of the lugs on the nuts with one another.

1. Field of the Invention
This invention relates to high pressure reciprocating plunger-type and piston-type pumps used in the petroleum industry, and more particularly, to a manifold for a front-discharge pump used in manifolding discharge valves positioned substantially coaxially with respect to the plungers in the pump. The invention also relates to a special nut used on the manifold.
2. Description of the Prior Art
It is common practice in the petroleum industry to employ high pressure plunger-type pumps in a variety of field operations relating to oil and gas wells, such as cementing, acidizing and fracturing, among others. An example of such a high pressure pump is the Halliburton Services HT-400 Horizontal Triplex Pump manufactured by Halliburton Services of Duncan, Okla., the assignee of the present invention. These pumps are frequently used in pumping two-phase slurries. Two-phase slurries are those in which solid particles (the "solid phase") are suspended in a liquid (the "liquid phase"). A problem with pumping such two-phase slurries is that the solid phase particles can separate out of the carrier liquid and can collect in valves, elbows, and in the fluid ends of the high pressure pumps in the system.
In the pumps, these particles tend to become packed ahead of the pump plunger or piston. This can result in sudden overpressurizing of the fluid in the pump with resulting damage to one or more of the plungers, connecting rods, crankshaft, fluid end, valves or other parts of the pump drive train.
Prior solutions to the overpressurizing problems are disclosed in U.S. Pat. No. 4,508,133 to Hamid and U.S. Pat. No. 4,520,837 to Cole et al., both assigned to the assignee of the present invention. These inventions comprise a protective cover assembly having a shear disc surrounded by an annular outer portion, mounted in a cylinder of the fluid end of the plunger-type high pressure pump. When a predetermined force is generated by the plunger in the cylinder, such as in an overpressure situation, the shear disc of the cover is sheared and is propelled outwardly against the plug. In turn, this forces the impact disc against an edge of a circular recess in the outer end of the retainer. The impact disc, in shearing against the recess edge, safely dissipates the kinetic energy of the shear disc, while the pressure in the cylinder vents to the atmosphere, avoiding damage to the fluid end of the pump, the plunger, connecting rod, crankshaft, etc. A problem with these devices is that the sheared disc is subjected to cyclic loading. Cyclic stress causes fatigue and premature failure of the disc around the thin arcuate wall may occur even at low pump pressures. Another problem is that the thin area around the arcuate portion does not leave much thickness for corrosion allowance, and thus may fail prematurely when corrosion is present. A further problem with previous apparatus is that the shear disc is expensive to fabricate, and machining may leave machine marks which act as stress risers and compound the fatigue problem already mentioned.
An apparatus which solves the fatigue problem is disclosed in U.S. Pat. No. 4,771,801 to Crump et al., also assigned to the assignee of the present invention. In this invention, a cover with a convex or domed center portion is used and is adapted for buckling away from the pump plunger when the pressure in the pump exceeds a predetermined level. The convex portion buckles when excessive force is transmitted from the plunger through any packed solid particles, allowing the packed particles to be pushed through vent passages.
Even though the apparatus of Crump et al. greatly reduces the risk of fatigue failure over Hamid and Cole et al., all three have two additional problems. First, once failure has occurred, the pump must be taken out of service immediately upon rupture of the protective cover. Secondly, a large quantity of the pump fluid can be spilled out of the pump when the cover ruptures. This limits the suitability of the apparatus for pumping some hazardous fluids. Also, the use of such shear discs obviously add somewhat to the operating costs of the pump in which they are employed.
In U.S. Pat. No. 5,073,096 to King et al., assigned to the assignee of the present invention, a pump fluid end is disclosed which solves the problems of the prior art by providing a pump in which a discharge valve is placed coaxially with the pump plunger or piston so that, if solid particles become packed ahead of the plunger, the force is transmitted through the particles to the discharge valve, pushing the valve open. This allows the packed particles to be pushed through the valve opening into the discharge passage. During this process, the pump may remain in use, and all fluids remain contained within the pump and its associated plumbing. The pressure containing envelope of the pump contains no designed "weak links" which present the possibility of failing and spilling fluid, as is possible in the other prior art.
A possible problem with using the apparatus of King et al. with conventional piping is that there may still be fluid flow problems in the discharge piping system. The present invention provides a front discharge manifold for the front discharge pump of King et al. The manifold is designed so that fluid flow therethrough will be smoother, thereby causing fewer pressure spikes. The reduction in such pressure spikes reduces the cyclic loading on the discharge valves and minimizes the fatigue resulting therefrom. The manifold also allows connection of multiple discharge valves even when the cylinders, and thus the discharge valves, are in close proximity to one another. By such a manifold, separate piping for each discharge valve is no longer necessary which reduce the costs and down time related to servicing.
Discharge valves which are close to one another may be manifolded because of a special nut which allows multiple connections to be made in a straight line while not interferring with nuts on adjacent cylinders. Basically, the invention allows more connections in a smaller space.

Manifold for a front-discharge fluid end reciprocating pump


A user request can be reflected in the degree of security of an updated key in quantum key distribution. A sender and a receiver are connected through optical fiber. A quantum transmitter in the sender and a quantum receiver in the receiver carry out basis reconciliation and error correction through a quantum channel, based on a source of a key sent from the quantum transmitter and on a raw key received by the quantum receiver. Under the control of security control sections in the sender and receiver, the amount of information having the possibility of being intercepted, which is determined in accordance with a degree of security requested by a user, is removed from the key information after error correction, whereby a final cryptographic key is generated. Secret communication is performed between encryption/decryption sections in the sender and receiver by using the cryptographic key thus updated.

1. Field of the Invention
The present invention relates to a secret communication system and, more particularly, to a system and method for allowing a sender and a receiver to share secret information.
2. Description of the Related Art
The internet has become the economic and social infrastructure over which various data are exchanged. Therefore, it is an important issue to devise preventive measures to protect data flowing over networks from risks of eavesdropping. One of the preventive measures is a secret communication system by which data for communication is encrypted. For encryption methods, there are two kinds of schemes: secret-key cryptography and public key cryptography.
Secret-key cryptography, as is typified by AES (Advanced Encryption Standard), is a scheme that uses a common encryption key for both encryption and decryption, and is capable of high-speed processing. For this reason, this scheme is used to encrypt data itself.
On the other hand, public key cryptography, as is typified by RSA (Rivest Shamir Adleman), is a scheme based on a one-way function, using a public key for encryption and a private key for decryption. Since this scheme is not suitable for high-speed processing, it is used to distribute a cryptographic key for the secret key scheme.
In secret communication where secrecy is ensured by encrypting data, an important thing to ensure the secrecy is that encrypted data cannot be broken even if the encrypted data is intercepted by an eavesdropper. To do so, it is necessary not to consecutively use the same key for encryption. This is because the consecutive use of the same key for encryption may increase the possibility that the encryption key is estimated based on the increased amount of intercepted data.
Accordingly, it is required to update an encryption key shared between a sender and a receiver. It is indispensable that the key being updated is not intercepted and broken during key update. Therefore, to update the key, there are two broad types of methods: (1) a method in which the key is encrypted for transmission by the public key cryptography, and (2) a method in which the key is encrypted for transmission by using a master key that is a common key preset for key update. (For example, see Japanese Patent Application Unexamined Publication Nos. 2002-344438 and 2002-300158.) The security according to these methods depends on the fact that an enormous amount of calculation is required for cryptanalysis.
On the other hand, quantum key distribution (QKD) technology, unlike ordinary (classical) optical communications, is a technology that allows a sender and a receiver to generate and share a cryptographic key by the transmission of a single photon per bit. This is a cryptographic-key-sharing technology that makes eavesdropping impossible, which has been proved on the basis of quantum mechanics (see Bennett, C. H., and Brassard, G., "QUANTUM CRYPTOGRAPHY: PUBLIC KEY DISTRIBUTION AND COIN TOSSING" IEEE International Conference on Computers, Systems, and Signal Processing, Bangalore, India, Dec. 10-12, 1984, pp. 175-179 (hereinafter, this document will be referred to as Bennett and Brassard), and Ribordy, G., Gauiter, J., Gisin, N., Guinnard, O., and Zbinden, H., "Automated 'plug & play' quantum key distribution" Electron Letters, Vol. 34, No. 22 (1998), pp. 2116-2117). However, since no perfect single-photon sources exist yet, single-photon transmission is achieved in practice by attenuating coherent light so that the mean number of photons per pulse becomes one or smaller, that is, the probability of the presence of two or more photons per pulse is reduced.
Here, one of the most typical quantum key distribution algorithms, called the BB84 protocol, will be described briefly with reference to Bennett and Brassard.
FIG. 1 is a schematic diagram showing a concept of a quantum key distribution method according to the BB84 protocol. It is assumed here that Alice (sender) 141 and Bob (receiver) 143 are connected through an optical transmission line 142. According to this method, Alice 141 has two random number sources, one of which (random number 1) provides source data of a cryptographic key, and the other one of which (random number 2) provides bases. Alice 141 randomly performs any one of four types of modulation (0, π/2, π, 3π/2) on each single photon depending on a combination of the random numbers, and sends it to Bob 143.
On the other hand, Bob 143 has a random number source (random number 3) corresponding to bases. When a value of the random number 3 is "0," Bob 143 performs a modulation of a phase of 0 (+basis) on a photon sent from Alice 141. When a value of the random number 3 is "1," Bob 143 performs a modulation of a phase of π/2 (x basis) on a photon sent from Alice 141. Thus, when bases used for modulation at Alice 141 and Bob 143 are the same (random number 2=random number 3), Bob 143 can correctly detect a corresponding value of the random number 1 (random number 1=random number 4). When bases are different (random number 2≠random number 3), Bob 143 randomly obtains 0/1 as a value of the random number 4, independently of a value of the random number 1. Since each of the random numbers 1, 2 and 3 is a sequence of random numbers that vary with each one bit, the probability that a match of bases occurs and the probability that no match of bases occurs are both 50%. However, since those bits corresponding to non-matching bases are removed in basis reconciliation at a subsequent stage, Alice 141 and Bob 143 can share a bit string of 0s and 1s based on the random number 1.
FIG. 2 is a flowchart showing a flow of quantum key generation in general. As described above, through quantum key distribution, an output of 0 or 1 (raw key) is obtained depending on the difference between the depths of phase modulation at Alice and Bob, and thereafter, by checking part of the bases used, a string of bits (sifted key) corresponding to matching bases is shared (basis reconciliation). As regards a prior art, Japanese Patent Application Unexamined Publication No. 2000-174747 discloses a quantum cryptography device that allows a sender and a receiver to share a sifted key by using a quantum channel and a classical channel.
However, the bit string shared as described above contains errors attributable to the transmission line 142 and/or receiver. Accordingly, error correction processing is required to correct these errors. In addition to this, an error also occurs in the shared bit string when an eavesdropper present on the transmission line intercepts the photon information. Therefore, to share a cryptographic key for final use, not only the error correction processing to correct errors, but also privacy amplification processing is required to reduce the amount of information that can be supposed to have been intercepted, based on the frequency of errors (error rate).
(Error Correction)
For the error correction processing, for example, a method as described in Brassard, G., and Salvail, L., "Secret-key Reconciliation by Public Discussion" in Advances in Cryptology—EUROCRYPT '93 Proceedings, Lecture Notes in Computer Science, Vol. 765, PP. 410-423, can be employed. According to this method, error correction is performed in such a manner that a bit string as a sifted key is divided into a plurality of blocks in each of a sender and a receiver, a block containing an error is located by checking the parity of each block, and the error is corrected by, for example, applying a Hamming code to the block in question. In addition, on the assumption that an even number of errors might be contained in one block, the bit string is permuted at random, and then parity check and error correction are performed again. Such work is repeated multiple times (V times), thereby detecting an error remaining in the secret bit string. For example, assuming that the number of parity check bits is approximately half the number of the bits in the sifted key, when parity check is repeated V times, the probability that a remaining error cannot be detected is 1/2V or lower. Since V-bit information has been leaked to a third party by such release of parity bits, these V bits are discarded from the key. Through this error correction process, G-bit key information is assumed to remain.
(Privacy Amplification)
For the privacy amplification processing, a method as described in Bennett, C. H., Brassard, G., Crepeau, C., and Maurer, U. M., "Generalized Privacy Amplification" IEEE Transactions in Information Theory, Vol. 41, No. 6 (1995), pp. 1915-1923, can be employed. The privacy amplification processing is a process for generating new random numbers by removing the amount of information that has the possibility of being leaked during key distribution. Here, the G-bit key information is sifted to yield a key of F bits (F<G). A specific procedure is as follows.
Alice generates random numbers (parity-calculation bits) inside and, for the G-bit key information Alice maintains, calculates the parity of bits at positions designated by the generated random numbers. Alice sets the calculated parity bit as the first bit of a key and sends these random numbers (parity-calculation bits) to Bob. Based on the received random numbers, Bob calculates parity for the G-bit key information Bob maintains, and sets that parity bit as the first bit of a key. By repeating such work, as much information as conceivably intercepted on the way along the transmission line is discarded, thereby creating a new F-bit final key. An eavesdropper cannot gain knowledge of new random numbers (final key) after privacy amplification unless she knows all the parity-calculation bits.
In the case where privacy amplification processing as described above is performed on G-bit key information after error correction to generate as many new random numbers as F bits, the number of bits, F, corresponding to the new random numbers is represented by the following equation:F=G−eG−V−S.
Here, e is the proportion of the information stolen by an eavesdropper intercepting the quantum communication. Therefore, it can be thought that the eavesdropper, Eve, possesses eG-bit information. V is the number of bits released in the process of remaining-error detection. S is a security parameter for privacy amplification. The larger the value of S, the closer to the perfect secrecy.
When an encryption key shared between a sender and a receiver is updated, there are several possible methods as described above, such as sending the updated key after encrypting it by the public key cryptography, or sending the updated key after encrypting it by using a common key preset for update. The security according to these methods is based on the fact that an enormous amount of calculation is required to break the encrypted key. Therefore, there has been a problem that the secrecy is degraded with improvement in cryptanalysis technology, such as improvement in computer power and improvement in cryptanalysis algorithms. For example, in the 56-bit DES challenge contests where teams compete in time to break DES (Data Encryption Standard), which is a common key cipher, although it took 96 days to break DES in 1997, the time was reduced to 22 hours in 1999. As for a public key cipher, although it took eight months to break a RSA public key cipher with a key length of 429 bits in 1994, it took about three months to break one with a key length of 576 bits in 2004. As described above, the cryptanalysis technology has been improving.
On the other hand, the quantum key distribution (QKD) technology has been studied and developed with an eye to implementing more secure systems. Accordingly, for the security of a key, attention has been focused only on the fact that whatever the attack, eavesdropping proves completely unsuccessful theoretically. For this reason, in QKD, the mean number of photons per pulse is fixed at 1.0 or smaller.
One of conceivable eavesdropping strategies in QKD is a photon-number splitting (PNS) attack, which is thought of as the most powerful attack at the present time. The PNS attack is a strategy in which one photon is stolen from a pulse including two or more photons, and further in the case of a pulse including one photon, information is stolen by entangling a photon. However, this strategy is difficult to realize, even unrealistic.
For a relatively realistic eavesdropping strategy, an intercept/resend attack is known in which Eve disguises herself as Bob to receive a signal from Alice and as Alice to send it on to Bob. If this eavesdropping is present, the error rate is, in principle, 25%. Also known is a strategy in which one photon is stolen from a pulse including two or more photons (beam splitting attack 1). However, according to this eavesdropping strategy, eavesdropping can be easily detected because the number of photons arriving at Bob is reduced. In addition, there is also a strategy in which an optical link from Alice to Bob is optically split at some point between Alice and Bob, and a part from this point to Bob is replaced with a lossless transmission link, thereby intercepting as much of the optical signal as is equivalent to the loss of transmission from the split point to Bob (beam splitting attack 2). However, this strategy is unrealistic in the lossless transmission link. Further, for another strategy that is difficult to realize, an individual (incoherent) attack is also known in which Eve entangles a photon with a photon being transmitted to copy the quantum state, thereby intercepting a small amount of information. If this individual (incoherent) attack only is applied, the amount of intercepted information does not depend on the number of photons. The above-mentioned PNS attack is the combination of the beam splitting attack 2 and the individual (incoherent) attack.
FIG. 3 is a graph schematically showing the relationship between the mean number of photons and the transmittable distance in a quantum key distribution system, for each different eavesdropping strategy. Each curve for its corresponding eavesdropping strategy indicates the border where, under the assumption that the eavesdropping strategy in question is performed, the amount of information shared between Alice and Bob becomes equal to the amount of information intercepted by Eve, in which case the key generation rate is zero. Where the transmission distance is longer than the distance indicated by the curve, the amount of intercepted information is larger, and it is impossible to generate a key. Where the transmission distance is shorter than the distance indicated by the curve, the amount of shared information is larger, and it is possible to generate a key. Additionally, the shorter the transmission distance, the higher the key generation rate.
From the viewpoint of the transmission distance, it is preferable to keep the mean number of photons per pulse much smaller than 1.0, in the case of seeking for the security at the level of beating the PNS attack. However, as can be seen from this graph, for the security at the level of beating the beam splitting attack 1, even if the mean number of photons is 1.0 to 4.0, it is possible to cover some transmission distance.
In other words, although it is necessary to set the number of photons per optical pulse at 1.0 or smaller in order to beat an attack of PNS class, the security of such highest level is not always required. Some users might put a higher priority on the transmission distance, key update rate, or amount of key, even if the security is sacrificed to some degree. In conventional quantum key distribution systems, it has been impossible to reflect a user request in the security of such an updated key.

Secret communication system and method for generating shared secret information


A reinforcement for a cast material for the fabrication of walls and ceilings of a structure which has two latticework beams interconnected by spaces using plastic plugs extending through aligned bores of the spacers and the longitudinal chords of the beams. The beams themselves have the longitudinal chords connected together by zig-zag strips and the longitudinal chords, zig-zag strips and spacers are all formed from galvanized sheet steel.

In a latticework beam known from German Patent 835 647, the continuous sheet steel strip of the diagonal bars runs so that the width of the strip is parallel to the plane of the latticework beam. It seems that the inventor considered this to be necessary, in order to achieve a connection between the longitudinal chords and the diagonal bars solely by clamping. Here the disadvantage is the lack of rigidity of the latticework beam in transverse direction, which is particularly noticeable during transport.

Latticework beam for reinforcing cast walls or ceilings


A previous amplifier circuit of the present invention includes: a grounded emitter amplifier circuit using a grounded emitter transistor connected to a light receiving device; another grounded emitter amplifier circuit using another grounded emitter transistor connected to another light receiving device; and a grounded emitter changing switch to be switched in a manner such that an emitter of the grounded emitter transistors is grounded so as to cause only one of the grounded emitter amplifier circuits to operate. A light-receiving amplifier circuit includes the previous amplifier circuit. An optical pickup apparatus includes the light-receiving amplifier circuit.

In the field of optical disks for recording sounds, images, and the like, a plurality of formats such as CD, DVD, and BD have been developed in recent years for the purpose of increasing recording capacity. This requires optical disk driving apparatuses for driving optical disks to be accommodated to optical disks of the plural formats. In view of the circumstance, there have been developed optical pickup apparatuses employing a package of two-wavelength laser device that emits laser light of two wavelength types (see publicly-known document 1 ("Japanese Unexamined Patent Publication No. 2004-22051 (published on Jan. 22, 2004)")).
FIG. 7 shows a configuration of an optical system in an optical pickup apparatus 101 employing a two-wavelength laser device.
The optical pickup apparatus 101 includes, as shown in the figure, a two-wavelength laser diode 103, a collimator lens 104, a beam splitter 105, an objective lens 107, a spot lens 108, and a light receiving amplification element 110.
Laser light emitted from the two-wavelength laser diode 103, which is a light emitting device serving as a light source for recording and reproduction, is changed into parallel light by the collimator lens 104. Thereafter, an optical path of the laser light thus changed is bent by 90° by the beam splitter 105, and then illuminates an optical disk 102 via the objective lens 107. Thereafter, light reflected from the optical disk 102 is converged by the spot lens 108 via the objective lens 107 and the beam splitter 105, and then comes incident on the light receiving amplification element 110. On the basis of incident light signals, the light receiving amplification element 110 reproduces information signals and generates focusing servo signals and/or focusing servo signals. The light receiving amplification element 110 then supplies a signal processing circuit (not illustrated), a control circuit (not illustrated), and the like with the signals thus reproduced and generated.
Meanwhile, the two-wavelength laser diode 103 emits laser light of two wavelength-types, depending upon the type of the optical disk 102 (in the present case, CD laser light having a wavelength of 780 nm and DVD laser light having a wavelength of 650 nm are emitted). In the two-wavelength laser diode 103, emission points from which the laser lights are emitted, respectively, are approximately 100 μm apart. In the optical pickup apparatus 101, a common optical system is used regardless of laser light. Therefore, in a same manner as the emission points in the two-wavelength laser diode 103, the laser lights come incident on locations that are approximately 100 μm apart, respectively, on the light receiving amplification element 110. Accordingly, in the case where the two-wavelength laser diode is employed, the light receiving amplification element needs to include a light receiving section for each laser light. In the present case, two light receiving sections, one for CD and the other one for DVD, need to be included.
FIG. 8 shows a light receiving section of the light receiving amplification element 110. As described above, light receiving sections (light receiving section 110A for DVD, and light receiving section 110B for CD) for the laser lights are provided, respectively. If, for example, a three-wavelength laser diode is developed in the future, obviously light receiving sections need to be included. Note that, as shown in the figure, each of the light receiving sections includes a main light-receiving section for information signals and a sub light-receiving section for tracking servo signals.
FIG. 9 shows a configuration of a light-receiving amplifier circuit 121 included in the light receiving amplification element 110. The light-receiving amplifier circuit 121, as shown in the figure, is configured with a previous amplifier circuit 122 and a following amplifier circuit 123.
The previous amplifier circuit 122, in the present case, includes two main light-receiving sections a (light receiving section for DVD) and A (light receiving section for CD), and an output changing switch S1 that causes an output of one of the main light-receiving sections a and A to be supplied to the following amplifier circuit 123.
The main light-receiving section a includes a photodiode PD1 and a trans impedance type amplifier circuit that is configured with an amplifier A1, which converts current generated in the photodiode PD1 into voltage and outputs the voltage, a feedback resistor R1, and a feedback capacitor C1. An anode of the photodiode PD1 is grounded. A cathode of the photodiode PD1 is connected to an input terminal of the amplifier A1. Further, the feedback resistor R1 and the feedback capacitor C1 are connected parallel to the amplifier A1. An output terminal of the amplifier circuit A1 is connected to the output changing switch S1.
The main light-receiving section A has a same configuration as the main light-receiving section a. The main light-receiving section A includes a photodiode PD2 and a trans impedance type amplifier circuit that is configured with an amplifier A2, which converts current generated in the photodiode PD2 into voltage and outputs the voltage, a feedback resistor R2, and a feedback capacitor C2. An anode of the photodiode PD2 is grounded. A cathode of the photodiode PD2 is connected to an input terminal of the amplifier A2. Further, the feedback resistor R2 and the feedback capacitor C2 are connected in parallel to the amplifier circuit A2. An output terminal of the amplifier circuit A2 is connected to the output changing switch S1.
The following amplifier circuit 123 includes an amplifier A3 and resistors R3 to R5.
One input terminal of the amplifier A3 is connected to one end of the resistor R3. The other end of the resistor R3 is connected to the output changing switch S1. One end of the resistor R4 is connected to a connection point of the one input terminal of the amplifier A3 and the one end of the resistor R3. The other end of the resistor R4 is connected to a terminal via which a reference voltage is externally supplied. The other input terminal of the amplifier A3 is connected to an output terminal of the amplifier A3 via the resistor R5. The output terminal of the amplifier A3 is an output terminal of the light-receiving amplifier circuit 121.
In the case where DVD laser light is emitted from the two-wavelength laser diode 103, reflected light from the optical disk 102 is supplied to the main light-receiving section a, and then converted from current into voltage. At this time, the output changing switch S1 is switched in a manner such that an output of the main light-receiving section a is supplied to the following amplifier circuit 123. Therefore, the output of the main light-receiving section a is supplied to the following amplifier circuit 123, amplified at the following amplifier circuit 123, and then outputted.
On the other hand, in the case where CD laser light is emitted from the two-wavelength laser diode 103, reflected light from the optical disk 102 is supplied to the main light-receiving section A, and then converted from current into voltage. An output of the main light-receiving section A is supplied to the following amplifier circuit 123 via the output changing switch S1, which is switched in a manner such that an output of the main light-receiving section A is supplied to the following amplifier circuit 123. Thereafter, the output of the main light-receiving section A is amplified at the following amplifier circuit 123 and then outputted.
Note that, concretely, the amplifier A1 of the main light-receiving section a is configured with a differential amplifier circuit that amplifies a difference between an output of the photodiode PD1 and the reference voltage supplied externally, and then outputs the difference thus amplified. In a same manner, the amplifier A2 of the main light-receiving section A is configured with a differential amplifier circuit that amplifies a difference between an output of the photodiode PD2 and the reference voltage supplied externally, and then outputs the difference thus amplified.
Meanwhile, to allow the light-receiving amplifier circuit 121, which is capable of accommodating the two-wavelength laser diode, to be included in an optical pickup apparatus for high-speed reproduction/recording, improvement in response frequency characteristics, output offset voltage, and output noise characteristics is required. To improve these respective characteristics, it is effective that each of the amplifiers A1 and A2, which is conventionally configured with a differential amplifier circuit, is configured with a grounded emitter amplifier circuit. The following describes reasons therefor.
First, the response frequency characteristics will be described, with reference to FIG. 10.
FIG. 10 shows response frequency characteristics of the respective amplifiers A1 and A2. Note that the response frequency characteristics of the respective amplifiers A1 and A2 are decided in accordance with formula (1) below:fc=1/(2πRC) (Hz)  (1)where R is a resistance of the feedback resistor R1 (or feedback resistor R2), and C is a capacitance of the feedback capacitor C1 (or feedback capacitor C2). Further, the feedback circuit in the figure corresponds to the feedback resistor R1 and the feedback capacitor C1 in the amplifier A1, and the feedback resistor R2 and the feedback capacitor C2 in the amplifier A2.
As shown in the figure, the amplifiers A1 and A2 have different response frequency characteristics from each other. Thus, limits of response frequencies as a result of feedback become frequencies f1 and f2, respectively.
At this time, even if the feedback capacitor C1 is set small in order to improve the response frequency characteristics of the amplifier A1, it is not possible to obtain a response equal to or greater than a certain frequency because the amplifier A1 is configured with a differential amplifier circuit (because the response frequency characteristics are slow in the case of open-loop). This is the same in the amplifier A2. Therefore, to improve the response frequency characteristics of the light-receiving amplifier circuit 121, it is required to set the feedback resistor R1 (or feedback resistor R2) small, or to improve the response frequency characteristics of the amplifiers in the case of open-loop.
Next, the following describes the output offset voltage. The output offset voltage is voltage that is outputted when no input signal is supplied to the light receiving section (when no reflected is supplied light from the optical disk 102).
It is ideal that the output offset voltage matches with the reference voltage supplied externally to the following amplifier circuit 123. However, an offset voltage is generated in the previous amplifier circuit 122 due to manufactural deviation and the like. The output offset voltage of the light-receiving amplifier circuit 121 is voltage generated at the following amplifier circuit 123 by amplifying the offset voltage of the previous amplifier circuit 122. Therefore, to restrain deviation in the output offset voltage, it is effective to reduce a gain of the following amplifier circuit 123.
Next, the following describes the output noise characteristics. In a same manner as the output offset voltage, it is effective with respect to the output noise characteristics to reduce a gain of the following amplifier circuit 123, because noise generated at the previous amplifier circuit 122 is amplified at the following amplifier circuit 123.
As described above, to improve the respective characteristics of the light-receiving amplifier circuit 121, it is required to improve the response frequency characteristics of the amplifiers, included in the previous amplifier circuit 122, in the case of open-loop, and to set a gain of the previous amplifier circuit 122 greater, as much as possible, than the gain of the following amplifier circuit 123.
Meanwhile, the grounded emitter amplifier circuit has excellent response frequency characteristics in the case of open-loop, and a characteristic of a wide dynamic range of outputs. Therefore, to improve the respective characteristics, it is effective that each of the amplifiers of the previous amplifier circuit 122 is configured with the grounded emitter amplifier circuit.
FIG. 11 shows an exemplary circuit in which the previous amplifier circuit is actually configured with a grounded emitter amplifier circuit.
A previous amplifier circuit 5 is configured with the photodiode PD1 (light receiving device), an grounded emitter amplifier circuit 1, an active load and bias circuit 2 of the grounded emitter amplifier circuit 1, an output circuit 3 configured with an emitter follower circuit, a feedback resistor R31, and a feedback capacitor C31.
The grounded emitter amplifier circuit 1 includes an NPN-type transistor (grounded emitter transistor) Q1. The active load and bias circuit 2 of the grounded emitter amplifier circuit 1 include PNP-type transistors Q3 and Q5, resistors R1 and R2, and a constant-current source I2. The output circuit 3 includes an NPN-type transistor Q4 and a constant-current source I1.
In the active load and bias circuit 2 of the grounded emitter amplifier circuit 1, a base of the transistor Q3 and a base of the transistor Q5 are connected. The base of the transistor Q5 is connected to a collector of the transistor Q5. The collector of the transistor Q5 is grounded via the constant-current source I2.
An emitter of the transistor Q3 is connected to one end of the resistor R2. An emitter of the transistor Q5 is connected to one end of the resistor R1. The other end of the resistor R1 and the other end of the resistor R2 are connected to a power supply Vcc.
An anode of the photodiode PD1 is grounded. A cathode of the photodiode PD1 is connected to a base of the transistor Q1. A collector of the transistor Q1 is connected to a collector of the transistor Q3. A connection point of the collector of the transistor Q1 and the collector of the transistor Q3 is connected to a base of the transistor Q4.
A collector of the transistor Q4 is connected to the power supply Vcc. An emitter of the transistor Q4 is grounded via the constant-current source I1. The feedback resistor R31 and the feedback capacitor C31, which is connected in parallel to the feedback resistor R31, are connected across the base of the transistor Q1 and a connection point of the emitter of the transistor Q4 and the constant-current source I1. The base of the transistor Q1 is an input terminal of the previous amplifier circuit 5. The connection point of the emitter of the transistor Q4 and the constant-current source I1 is an output terminal Vo of the previous amplifier circuit 5.
Meanwhile, to allow the previous amplifier circuit 5 configured with the grounded emitter amplifier circuit as described above to be included as the previous amplifier circuit 122, which is capable of accommodating a two-wavelength laser diode, of the light-receiving amplifier circuit 121 of the conventional technique described above, it is necessary to include two light receiving sections. In order to do so, it is necessary to include a plurality of the circuit surrounded by the dashed-dotted line in FIG. 11. This causes a big problem of increase in the number of elements. Note that a conventional technique is found in publicly-known Document 2 ("Japanese Unexamined Patent Publication No. 2001-202646 (published on Jul. 27, 2001)").

Previous amplifier circuit, light-receiving amplifier circuit, and optical pickup apparatus having grounded emitter amplifier circuits each with a grounded emitter transistor


A method of creating a two-dimensional representation of a model. The method includes receiving data corresponding to a first component and at least one second component of the model, defining a first component representation, defining the at least one second component representation, determining a visibility of the plurality of graphics of the first component representation, determining a visibility of the plurality of graphics of the at least one second component representation, defining a structure of the first component representation, defining a structure of the at least one second component representation, defining one or more display rules, and generating an illustration file.

The present disclosure relates generally to systems and methods of creating a two-dimensional representation of a model, and more specifically, to systems and methods for creating and storing a plurality of configurations (e.g., combinations of visible components) of a two-dimensional illustration in a single standard illustration file that enables a user to interactively display a selected configuration.
Conventional systems and methods of creating a two-dimensional model use lines to represent visible edges of a component. For example, as shown in FIG. 1, a two-dimensional model that includes components 102 and 104 is shown. Each component includes lines that represent edges of a cube. However, a placement and orientation of components may result in components overlapping other components. For example, as shown in FIG. 2, component 102 overlaps a portion of component 104. To preserve an appearance of each of the components, the overlapped segments of the lines from component 104 may be removed, as shown in FIG. 3. When a selected configuration does not include components that overlap other components, visible components may be missing segments of lines that represent the visible components, as shown in FIG. 4

Systems and methods for creating a two-dimensional representation of a model


The subject application is directed to a system and method for rapid switching between anycast multicast sources. Multiple streams of data are received by a server. The server associates a separate source address to each of the received streams and sources the multiple streams of data with the associated addresses to a recipient. The server determines whether each of the multiple streams of data is up or down. The server periodically sends status information with the associated address for each of the multiple streams of data to the recipient indicating whether each of the multiple streams of data is up or down.

1. Field of the Invention
The present invention relates to networking and, more specifically, to a method and system for reliably transmitting IPmc streams of data over a network.
2. Description of the Background Art
While the concept of anycasting is well known, it is most often applied to services where unicast traffic is sent towards an anycast address as a form of redundancy for a service. When IP (Internet Protocol) multicast is used, it is also feasible to source IP multicast traffic from an anycast address to provide server redundancy. Current implementations have some limitations. For example, assume that two or more servers at separate physical locations in a network source the same content. Both servers are assigned the same IP address. A local router for each of the servers is configured to advertise this address to the network as a host route so that clients in the network will connect to the nearest anycast server. One use of anycast servers is to source video data. Anycast multicast video servers in video networks provide both load balancing and redundancy. For example, some video servers receive multiple MPEG ASI video streams that are packetized into separate multicast streams. The servers then send the data as multicast to a destination by way of network routers.
Sometimes, a server will not transmit one or more of its data streams due to loss of input signal to the server. In conventional systems, if only a single data stream from a server goes down (e.g., an MPEG video stream) while all other streams from the server remain up, there is no way to restore the lost single stream, short of manually switching to another server that has all streams up. In this situation, the physical connection between the anycast server and the router has not gone down. The router is sending some legitimate streams of data; it is just not sending all of its streams. Conventional systems determine that a server is unavailable and not sending by looking at the physical interface between the server and the router. Unfortunately, because the physical interface between the anycast server and the router has not gone down, the router will not be able to detect a loss of physical connection and withdraw the host route from the network.
Sometimes a physical connection between a server and a router goes down. If the router connects to the server through switch interfaces, the router will be unaware that the physical link from the server to the switch has gone down. The actual application on the server appliance generating one or more video streams may be incapable of generating a link up/down signaling on its interface.
What is needed is some way for the routers to determine when some but not all streams from a server have gone down so that the router can withdraw the associated anycast host route from the network and force the network to switch to a remaining anycast source in the network.

Server to network signaling method for rapid switching between anycast multicast sources


A golf club head comprising a club head body removably coupled at different times with various attachment members in a recess of the club head body. In some embodiments, the golf club head comprises different characteristics when coupled with different attachment members. In some embodiments, different attachment members alter characteristics, such as bounce height, while maintaining other characteristics, such as loft angle and/or bounce angle.

The bounce angle of a golf club can impact the flight distance and/or accuracy of the golf ball, but the bounce height (i.e., the rise in the bounce angle) can have an even greater impact on the flight distance and/or accuracy of the golf ball. Specifically, the bounce angle and/or bounce height can determine how easily a golf club head can penetrate the ground under the golf ball during a golf club swing. However, ground conditions are subject to change such that the ground may be harder or softer at certain times due to weather, grooming, etc. Accordingly, a club head with a particular bounce angle and/or bounce height configuration may be better in certain circumstances than in other circumstances.
For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "include," and "have," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.
The terms "left," "right," "front," "back," "top," "bottom," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

This patent is subject to a terminal disclaimer.

Variable bounce height club heads and related methods


A method for producing an aromatic poly(thio)ether ketone having repeating units of the following formula (II): ##STR1## wherein each of R.sup.1 to R.sup.12 is a hydrogen atom, a halogen atom, a hydrocarbon group or an alkoxy group, X is an oxygen atom or a sulfur atom, provided that part of X may be a direct bond, and n is an integer of from 0 to 2, which comprises reacting an aromatic (thio)ether carboxylic acid fluoride of the following formula (I): ##STR2## wherein R.sup.1 to R.sup.12, X and n are as defined above, under pressure in an aprotic organic solvent in the presence of boron trifluoride.

1. Field of the Invention
The present invention relates to a method for producing a linear crystalline thermoplastic aromatic poly(thio)ether ketone having a high degree of polymerization.
2. Discussion of Background
Aromatic poly(thio)ether ketones having a structure of the following formula (II): ##STR3## wherein each of R.sup.1 to R.sup.12 is a hydrogen atom, a halogen atom, a hydrocarbon group or an alkoxy group, X is an oxygen atom or a sulfur atom, provided that part of X may be a direct bond, and n is an integer of from 0 to 2, particularly aromatic poly(thio)ether ketones having structures of the following formulas (III) and (IV), have high melting points [(III): Tm=365.degree. C.; (IV): Tm=334.degree. C.] and high glass transition points [(III): Tg=154.degree. C.; (IV): Tg=144.degree. C.], and they are known to be polymers which are excellent in the heat resistance, mechanical properties, electrical properties and dimensional stability and which have low water absorption and excellent physical properties. Further, they are insoluble in solvents other than concentrated sulfuric acid and thus are polymers excellent also in the chemical resistance. ##STR4##
Heretofore, as a method for producing these polymers, a method of reacting 4,4'-difluorobenzophenone with 4,4'-dihydroxybenzophenone or with an alkali metal salt of dihydroquinone in diphenylsulfone (Japanese Unexamined Patent Publications No. 90296/1979 and No. 89334/1980) or a method of conducting self-condensation of an alkali metal salt of 4-fluoro-4'-hydroxybenzophenone in diphenylsulfone (Japanese Unexamined Patent Publication No. 16946/1985), has been known. However, such a method has many drawbacks such that the reaction temperature is required to be at least 300.degree. C., and 4,4'-difluorobenzophenone or 4-fluoro-4'-hydroxybenzophenone is expensive.
As other methods, a method of reacting 4-phenoxybenzoyl chloride in a hydrogen fluoride solvent in the presence of boron trifluoride (Japanese Examined Patent Publication No. 451/1981) and a method of reacting diphenyl ether and a S-alkyl-thiochloroformate in a hydrogen fluoride solvent in the presence of boron trifluoride (Japanese Unexamined Patent Publication No. 171181/1983) are known. However, each of these methods has many drawbacks, such that a highly corrosive solvent like hydrogen fluoride is employed.
As a method for producing aromatic polyether ketones of the formula (III), etc., a method of polymerizing 4-phenoxybenzoyl chloride or 4,4'-diphenyl ether dicarboxylic acid dichloride with diphenyl ether in 1,2-dichloroethane in the presence of anhydrous aluminum trichloride, is also known (M. I. Litter and C. S. Marvell, J. Polym. Sci; Polychen Ed. 23, 2205-2223 (1985)). However, this method requires a large amount, i.e. more than equivalent, of aluminum chloride, and it is thereby difficult to recover aluminum chloride thus used, whereby a large amount of the aluminum compound will have to be disposed by post treatment. Thus, this method is not suitable for application as an industrial process.
Under these circumstances, the present inventors have conducted extensive researches and, as a result, have found it possible to obtain a polymer having a high degree of polymerization by polymerizing an acid fluoride of the following formula (I) under pressure in the presence of a non-corrosive aprotic organic solvent without using a corrosive solvent such as hydrogen fluoride and by using boron trifluoride which can be recycled, instead of the aluminum chloride. The present invention has been accomplished on the basis of this discovery. ##STR5## wherein each of R.sup.1 to R.sup.12 is a hydrogen atom, a halogen atom, a hydrocarbon group or an alkoxy group, X is an oxygen atom or a sulfur atom, provided that part of X may be a direct bond, and n is an integer of from 0 to 2.
Thus, the present invention provides a method for producing an aromatic poly(thio)ether ketone having repeating units of the following formula (II): ##STR6## wherein R.sup.1 to R.sup.12, X and n are as defined above, which comprises reacting an aromatic (thio)ether carboxylic acid fluoride of the above formula (I) under pressure in an aprotic organic solvent in the presence of boron trifluoride.
Now, the present invention will be described in detail.
Specific examples of the aromatic (thio)ether carboxylic acid fluoride of the above formula (I) to be used in the present invention, include 4-phenoxybenzoyl fluoride, 4-phenoxy-4'-fluoroformyldiphenyl ether, 3-phenoxybenzoyl fluoride, 4-phenyl-4'-fluoroformyldiphenyl thioether, 3-methyl-4-phenoxybenzoyl fluoride, 3-methoxy-4-phenoxybenzoyl fluoride and 4-phenylmercaptobenzoyl fluoride. However, any one represented by the formula (I) can be used, and the compound of the formula (I) is not limited to the above specific examples. These aromatic (thio)ether carboxylic acid fluorides may be used alone or in combination as a mixture. Among them, 4-phenoxybenzoyl fluoride is particularly preferred.
The aprotic organic solvent to be used as a solvent in the present invention may, for example, be a hydrocarbon, a halogenated hydrocarbon, an aliphatic ether, a ketone, a compound having a nitro group, or other compounds. Specific examples include methylene chloride, dichloroethane, 1,1,2,2-tetrachloroethane, chloroform, carbon tetrachloride, nitrobenzene, nitromethane, carbon disulfide, o-dibromobenzene, o-dichlorobenzene, m-dichlorobenzene, diphenylsulfone, diphenylketone, chlorobenzene, benzene, toluene, acetophenone, tetralin, decalin, hexane, dibutyl ether, heptane and pentane. However, the aprotic organic solvent is not limited to such specific examples. Among these solvents, a halogenated hydrocarbon is preferred. More preferred is a halogenated aromatic hydrocarbon. Particularly preferred is o-dichlorobenzene. These aprotic solvents may be used alone or in combination as a mixture.
The solvent is used in an amount of from 1 to 100 parts by weight, preferably from 5 to 100 parts by weight, per part by weight of the organic (thio)ether carboxylic acid fluoride of the formula (I).
The boron trifluoride for the present invention is used in an amount of from 0.5 to 100 parts by weight, preferably from 0.9 to 50 parts by weight, per part by weight of the aromatic (thio)ether carboxylic acid fluoride of the formula (I).
There is no particular restriction as to the reaction temperature in the present invention. However, it is usual to conduct the reaction at a temperature of from -10.degree. to 200.degree. C., preferably from 30.degree. to 150.degree. C. There is no particular restriction as to the reaction pressure, but the reaction is usually conducted under pressure. Preferably, the pressure is at least 5 atm.
According to the present invention, a linear poly(thio)ether ketone having a high degree of polymerization can be obtained in good yield.
The aromatic polyketone obtained by the present invention has many merits. Namely, it is excellent in the mechanical properties such as the tensile strength, flexural strength and tensile modulus of elasticity, the heat resistance, the thermal decomposition initiation temperature, the electrical properties and the dimensional stability and has a low moisture and water absorptivity.
Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.

Method for producing an aromatic poly (thio) ether ketone


A method for managing a system includes monitoring a plurality of applications running in the system for errors. A prediction is made as to whether errors detected would result in a failure. Fault recovery is initiated in response to a failure prediction. According to one aspect of the present invention, monitoring the plurality of applications includes reading error recorders associated with error occurrence. Other embodiments are described and claimed.

Software applications running on computer systems may experience a variety of errors that may affect its operational state. Errors which software applications may experience include, for example, errors relating to memory allocation, memory corruption, segment violation, unexpected state transitions, interprocess communication between applications, and timer related system calls. It is important for a computer system to recognize an application's operational state in order to allow for the computer system to take recovery actions and prevent the degradation of operational services.
Some software applications are capable of logging errors internally to be reviewed by the computer system user or a system manager. Other software applications are capable of generating an error report that may be transmitted outside the computer system to be reviewed by a software developer. These logs or reports typically include information about the error, such as the time it occurred and information about the nature of the error. Although these applications are capable of logging and reporting errors, no further action is typically taken during the application run time. Eventually, if the errors reach a high enough severity level, the result may be a software application failure or worse, an operating system failure. These failures may cause valuable data to be lost from the application. In the event of an operating system failure, data may also be lost from other applications and operational services may be interrupted.
Thus, what is needed is an effective method and apparatus for managing errors in a computer system to predict failures in advance and to take appropriate recovery action.

Method and apparatus for managing software errors in a computer system


A method is provided for manufacturing an optical data recording medium including a plurality of data recording layers each having a user data recording region and a BCA formation region positioned at an inner position than the data recording region. The method includes: forming a first data recording layer out of the plurality of data recording layers on a first substrate; forming a second data recording layer out of the plurality of data recording layers on a second substrate; forming a BCA pattern within the BCA formation region of the second data recording layer to record burst cut data; and bonding the first and second substrates after the BCA pattern is formed.

1. Field of the Invention
The present invention relates to an optical data recording medium and method of manufacturing the same, more particularly, relates to formation of a burst cut area (BCA) within an optical data recording medium.
2. Description of the Related Art
Optical discs, which are configured to record and reproduce data by using a laser beam, are widely-used recording media. Optical discs include read-only optical discs on which a series of emboss pits are formed in the disc manufacture process, such as CD-ROMs and DVD-ROMs, write-once optical discs, such as CD-Rs and DVD-Rs, and rewritable optical discs, such as CD-RWs, DVD-RWs and DVD-RAMs.
In general, an optical disc is designed to record and reproduce data by laser beam irradiation on a data recording layer through a transparent substrate. Within the data recording layer, a pit array or a groove is formed along a spiral recording track.
One sort of optical disc includes a burst cut area (BCA) which is a data recording region provided separately from the spiral recording track. As shown in FIG. 1A, a BCA 101 is provided at a predetermined radial position in the inner region of the optical disc. As shown in FIG. 1B, which illustrates an enlarged view of a portion A of the BCA 101, a set of radially-extending segments 101a having a low reflectance are formed within the BCA 101, and the BCA 101 records desired data as the pattern of the low-reflectance segments 101a. The BCA 101 is as sort of a bar code formed circumferentially. Hereinafter, the pattern of the low-reflectance segments 101a may be referred to as the BCA pattern and the data recorded within the BCA 101 may be referred to as the burst cut data. The BCA 101 may be provided along a part of a circumference as shown in FIG. 1A, or provided along the whole of a circumference. The burst cut data recorded in the BCA 101 typically include identifier for identifying the optical disc, optical disc type data (such as, read-only, write-once and rewritable) and copyright control data.
Referring back to FIG. 1B, the low-reflectance segments 101a are circumferentially arranged at a predetermined radial position of the optical data recording medium. The segments 101a have a fixed length along the radial direction, and the segments 101a are patterned along the circumference, depending on data to be recorded. It should be noted that a recording track, which is to be tracked by the laser spot, is not provided within the BCA 101. The SCA 101 is scanned by the laser spot along the circumference direction indicated by the arrow S, which is same as the disc rotation direction. The reflected light intensity changes depending on the BCA pattern (that is, the pattern of the low-reflectance segments 101a and the high-reflectance portions 101b), and the change in the reflected light intensity is detected as a signal. This signal is used for reproducing the data recorded in the BCA 101.
Compared with data recording with pits, one advantage of the data recording onto the BCA is that the use of the BCA allows recording different data onto different optical data recording media. For example, the use of BCA allows recording copyright control data onto each optical data recording medium. One approach of the BCA formation within a read-only optical data recording medium is to partially remove a metal reflective film within a data recording layer by irradiation of a strong laser beam, and to thereby form low-reflection segments within the read-only optical data recording medium. This approach is inferior in the fineness, compared with the formation of pits. For example, the low-reflectance segments 101a actually have a width of about 10 μm or more, and the largest interval between adjacent low-reflectance segments 101a is 100 μm or more.
Recently, optical discs with two data recording layer have become commercially available, which are adapted to record and reproduce data through one light-incident surface. FIG. 2 illustrates an example of the section structure of an optical data recording medium with two data recording layers. The optical data recording medium of FIG. 2, denoted by the numeral 1, incorporates a zero-th data recording layer 10 and a first data recording layer 11. Each of the data recording layers 10 and 11 includes a film stack including a phase-change recording film. The data recorded onto the data recording layers 10 and 11 are reproduced by using a focused beam irradiated through the light-incident surface 1A.
The distance between the zero-th data recording layer 10 and the first data recording layer 11 is preferably in the range in which the aberration of the focused beam passing through a transparent substrate 14 of the optical data recording medium 1 is not largely changed. Therefore, the distance is adjusted to about 50 μm in a DVD-ROM, for example. In this case, the diameter of the focused beam at the zero-th data recording layer 10 is about 40 μm when the focused beam is focused on the first data recording layer 11. This value is in the same order as intervals of the low-reflectance segments 101a within the BCA 101.
Therefore, when the focused beam is focused on one of the data recording layers 10 and 11, the focused beam experiences considerable interference caused by the other of the data recording layers 10 and 11. In order to avoid this, the BCA is formed within only one of the two data recording layers 10 and 11.
In this case, it would be advantageous if the BCA is formed within predetermined one of the data recording layers 10 and 11; this effectively reduces the time duration necessary for a recording apparatus or a reproducing apparatus to identify the optical data recording medium. When the data recording layer with the BCA is unknown, it is necessary to access both of the data recording layers 10 and 11 to find the BCA. When the BCA is formed within fixed one of the data recording layers 10 and 11, on the other hand, the data recorded within the BCA is reproduced in a short time through accessing only one of the data recording layers in which the BCA is formed.
When the optical data recording medium 1 is a read-only medium with two data recording layers, the first data recording layer 11 incorporates a metal reflection layer to provide a sufficient amplitude for a reproduced signal. As shown in FIG. 3A. a BCA is formed for such read-only medium through irradiating a laser beam through another light-incident surface is, which is opposed to the light-incident surface 1A used for the data recording and reproduction; such technique is disclosed in Japanese Laid Open Patent Application No. JP-A 2005-135569 and the corresponding U.S. Patent Application Publication NO. 2005/0078594. The metal reflective film within the first data recording layer 11 is partially removed by the laser beam to thereby form the BCA. Data reproduction from the first data recording layer 11 is achieved with a laser beam passing through the zero-th data recording layer 10. Therefore, the first data recording layer 11 is formed to have an increased reflectance sufficient for providing a necessary amplitude for the reproduced signal. Typically, the metal reflective film within the first data recording layer 11 has an increased film thickness so that the transmittance of the metal reflective film is reduced down to 10% or less.
When the transmittance of the zero-th data recording layer 10 is T0 and the individual reflectance of the first data recording layer 11 is R1, the total reflectance R of the structure composed of the zero-th and first data recording layers 10 and 11 is represented by the following formula:R=R1×T0.The individual reflectance R1 of the first data recording layer 11 should be increased up to 60% or more for increasing the total reflectance R up to 15% or more, when the transmittance T0 of the zero-th data recording layer 10 is 50%. When a silver reflective film is incorporated within the first data recording layer 11, for example, the silver reflective film is required to have a thickness of about 50 nm for achieving a reflectance of 60%. In this case, the first data recording layer 11 has a transmittance of about 10%. Therefore, when a laser beam is radiated from the side of the first data recording layer 11, the laser beam seldom transmits through the first data recording layer 11. The reflection beam from the zero-th data recording layer 10 is not detected, and this allows the focus servo control to surely focus the laser beam on the first data recording layer 11.
As for a rewritable optical disc, the BCA is formed through irradiating a laser beam on a phase-change film to change the optical characteristics thereof, instead of removing the metal reflective film; this process is similar to that of recording user data onto the rewritable optical disc. For a read-only medium in which each data recording layer consists of a single metal film, the BCA is formed through partially removing the metal reflective film by using a laser beam. However, such process is not applicable to rewritable optical disc, in which each data recording layer consists of a film stack. It is difficult to finely remove all the desired portions of the film stack by laser irradiation. The BCA formation within a rewritable optical disc is achieved by using an approach similar to user data recording.
For the BCA formation of a read-only medium, a laser beam is irradiated from the side of the first data recording layer 11. This allows surely focusing the laser beam on the first data recording layer 11. The formation of a BCA within a rewritable multilayer optical disc, on the other hand, requires irradiating a laser beam from the side of zero-th data recording layer 10. The reason is as follows: Since the first data recording layer 11 incorporates a metal reflective film having a low transmittance, the laser beam irradiated from the side of the first data recording layer 11 is hard to transmit the first data recording layer 11. Therefore, the intensity of the laser beam transmitted through the first data recording layer 11 is not so high that the temperature of the phase-change film is increased to change the optical characteristics thereof. This implies that the BCA formation requires irradiating a laser beam from the zero-th data recording layer 10, which has a high transmittance, to thereby increase the temperature of the phase-change recording film within the first data recording layer 11.
However, the laser beam is not necessarily focused on the first data recording layer 11, when the laser beam is irradiated from the side of the zero-th data recording layer 10. For a read-only medium, in which the first data recording layer 11 has an extremely low transmittance, a change of a focus error signal 7, which is often called the S-shaped curve, is observed only once as shown in FIG. 3A, when the laser beam is irradiated from the side of the first data recording layer 11. As for a rewritable optical disc, on the other hand, two S-shaped curves are observed as shown in FIG. 3B, one of which is caused by the zero-th data recording layer 10, and the other is caused by the first data recording layer 11. The laser beam is controlled to be focused on the first data recording layer 11 on the basis of one obtained from the first data recording layer 11 out of the two S-shape curves. However, the laser beam may be erroneously focused on the zero-th data recording layer 10, due to the S-shape curve obtained from the zero-th data recording layer 10. When the laser beam is erroneously focused on the zero-th data recording layer 10, the BCA is undesirably formed within the zero-th data recording layer 10. A multilayer optical disc in which a BCA is formed within the zero-th data recording layer 10 is an unusable defective product.
Correspondingly, the laser beam is required to be focused on the zero-th data recording layer 10 when a BCA is formed within the zero-th data recording layer 10; however, the laser beam may be erroneously focused on the first data recording layer 11, and a BCA may be accidentally formed within the first data recording layer 11.
As described above, fixing the data recording layer within which the BCA is formed effectively reduce the time duration necessary for medium identification; however, the conventional approach suffers from a difficulty in surely forming a BCA within a desired data recording layer in a rewritable data recording medium with multiple data recording layers. A rewritable data recording medium with multiple data recording layers in which a BCA is formed within an undesired data recording layer is an unusable defective product.
Japanese Laid Open Patent Application No. WO2002/037483 and the corresponding U.S. Patent Application Publication No. 2003/0076775 disclose a technique for forming a BCA within an optical disc with two data recording layers. In this technique, first and second data recording layers are formed on first and second substrates, respectively, and then a BCA is formed only within the first data recording layer. This is followed by bonding the first and second substrates by an intermediate layer. Japanese Laid Open Patent Application No. JP-A 2002-313031 and the corresponding U.S. Patent Application Publication No. 2002/0150031 disclose a similar technique.

Optical data recording medium and method of manufacturing the same


A process for producing a ferric aminopolycarboxylic acid chelate with improved long term stability is disclosed. The process involves heating a mixture of iron oxide, ammonia and aminopolycarboxylic acid chelant at an elevated temperature for a sufficient time to improve the stability of the formed chelate.

The present invention is to a process for producing ferric-aminopolycarboxylic acid chelates with improved long term stability.
In the photographic industry, the oxidation of metallic silver in photographic images or negatives to silver ion is known as bleaching. A desirable bleaching agent will react rapidly with silver and then react rapidly with air to regenerate the bleaching agent. Ferric compounds have been used for this purpose for decades. The ferric compound in the most widespread use today is ferric ammonium ethylenediaminetetraacetate because of its desirable redox properties and ease of preparation from inexpensive commercial chemicals such as, ferrosoferric oxide, ethylenediaminetetraacetic acid (EDTA) and ammonia.
Donovan and Surash, U.S. Pat. No. 3,767,689, and Svatek, et al. U.S. Pat. Nos. 4,364,871, and 4,438,040, describe the formation of ferric-aminopolycarboxylic acid chelates by the reaction of iron oxide with ammoniated EDTA in an aqueous mixture at temperatures up to 105.degree. C. for less than three hours, followed by pH adjustment, aeration, and filtration to give a ferric ammonium EDTA solution suitable for bleaching. A more recent variation of the method, described by Thunberg, et al. (U.S. Pat. No. 5,110,965), involves the use of ferrous salts to catalyze the reaction between the iron oxide and ammoniated EDTA.
Whereas chelate solutions made by the aforementioned processes are useful for photographic bleaching, over time they deposit fine, black, particulate matter which would be detrimental to the quality of photographs prepared using said solutions. It would be desirable, therefore, to produce ferric ammonium EDTA solutions which are more stable against the formation of the dark particulates.

Preparation of aminopolycarboxylate-ferric solutions with improved long-term stability


Disclosed herein is a printing control apparatus for enabling an image forming apparatus, having a network connection function and printing data interpretation function, to print printing data written in a format that cannot be interpreted by the interpretation function of the image forming apparatus. The printing control apparatus, connected between a network and an image forming apparatus having a network interface, determines whether or not a data packet received from the network is printing data (S303), and when the received data packet is printing data, encodes the received data packet in a format interpretable by the image forming apparatus (S305) to be outputted to the image forming apparatus.

Conventionally, in a case where an apparatus having an image forming function (hereinafter referred to as an image forming apparatus), e.g., a copying machine, printer, facsimile, multi-function apparatus and so on, is connected to a computer network (hereinafter simply referred to as a network) such as a local area network (LAN), an image forming apparatus having network connection means, e.g., a network interface or the like, and an image forming apparatus not having network connection means employ different connection methods.
FIG. 10 is a view of a LAN structure, shown as an example of a network, connecting an image forming apparatus including a network interface and an image forming apparatus not including (or incapable of including) a network interface.
Referring to FIG. 10, reference numeral 5001 denotes a LAN; 5002, an image forming apparatus not having a network interface; 5003, a printer server which enables the image forming apparatus 5002 to connect to the LAN 5001 to serve as a network printer; 5004, a conventional interface used for local connection, typically exemplified by IEEE 1284 (so-called parallel interface); 5005, a communication cable serving as a communication medium of the interface 5004; 5006, a network interface for connecting to the LAN 5001; 5007, an image forming apparatus having a network interface directly connectable to the LAN 5001; 5008, a network interface connecting the image forming apparatus 5007 to the LAN 5001; and 5009, a terminal apparatus connected to the LAN.
Although not shown in the drawing, generally plural terminal apparatuses 5009 are connected to the LAN 5001 as a printing client or a controller of other apparatuses.
The image forming apparatus 5002, which does not have means to connect to the LAN 5001, generally employs the printer server 5003 to communicate with the terminal apparatus 5009 which is connected to the LAN 5001. More specifically, the printer server 5003, having the interface 5004 that is also included in the image forming apparatus 5002, is connected to the image forming apparatus 5002 through the communication cable 5005. Meanwhile, the printer server 5003 is connected to the LAN 5001 through the network interface 5006. By virtue of the above construction, the image forming apparatus 5002 can perform data communication with the terminal apparatus 5009.
When the terminal apparatus 5009 transmits data (packet data) to the printer server 5003, the data is propagated to the LAN 5001 and captured by the printer server 5003 through the network interface 5006. The processing performed by the printer server 5003 is now described with reference to the flowchart in FIG. 11.
When the printer server 5003 receives the data packet (step S5101), the printer server 5003 determines whether the received data is printing data or control data by analyzing, for instance, the packet header portion (step S5102). When the received data is determined as printing data, portions that are not related to printing processing, e.g., the header or footer added for communication through the LAN, are removed from the data, thereby extracting printing data (step S5103). The printing data, extracted in the foregoing manner, is again formed into a packet having a structure suitable to the conventional interface 5004 of the image forming apparatus 5002 (step S5104), and transmitted to the image forming apparatus 5002 (step S5105). The data packet is transmitted to the image forming apparatus 5002 through the communication cable 5005 and interface 5004. The image forming apparatus 5002 processes the data packet and performs image formation on a printing medium based on contents of the data packet. Accordingly, printing processing instructed by the terminal apparatus 5009 is completed.
Meanwhile, if it is determined at the determination step (step S5102) that the received data is control data, the printer server 5003 interprets the control data (step S5106). The control data is converted to a command system that can be interpreted by the image forming apparatus 5002 (step S5107), and transmitted to the image forming apparatus 5002 (step S5105). The image forming apparatus executes processing in accordance with the received command (e.g., performs on-line or off-line control).
Depending on the printer server, there is a type which extracts printing data (step S5103), interprets a page description language (PDL) included in the printing data and converts it to a language that can be interpreted by the image forming apparatus 5002, then forms the converted data into a packet (step S5104), and transmits the packet to the image forming apparatus 5002 (step S5105).
Next, processing performed by the image forming apparatus 5007, which includes a network interface as means to directly connected to the LAN 5001, is explained with reference to the flowchart in FIG. 12.
The data packet from the terminal apparatus 5009 is transmitted directly to the image forming apparatus 5007. The data packet is propagated to the LAN 5001, and captured by the image forming apparatus 5007 through the network interface 5008.
When the image forming apparatus 5007 receives the data packet (step S5201), the image forming apparatus 5007 determines whether the received data is printing data or control data by analyzing, for instance, the packet header portion (step S5202). When the received data is determined as printing data, portions that are not related to printing processing, e.g., the header or footer added for communication through the LAN 5001, are removed from the data, thereby extracting printing data (step S5203). The printing data, extracted in the foregoing manner, is subjected to raster image processing (RIP) (step S5204). RIP, also called rasterizing processing, is processing for converting a received page description language (PDL) to raster image data. The raster image data, obtained by the conversion processing, is subjected to printing processing (step S5205) for image formation on a printing medium. Accordingly, printing processing instructed by the terminal apparatus 5009 is completed.
Meanwhile, if it is determined at the determination step (step S5202) that the received data is control data, the image forming apparatus 5007 interprets the command (step S5206) and executes processing in accordance with the command (step S5207) (e.g., performs on-line or off-line control).
Depending on the type of image forming apparatus 5007 having a network interface, there is a type incapable of interpreting a printing language such as a PDL. An image forming apparatus of this type does not operate solely as a printer, but has a capability to perform image formation in cooperation with other apparatuses connected to the LAN 5001. For instance, the image forming apparatus receives scanner-read image data directly from a network scanner connected to the LAN 5001, or receives image data encoded in a compression form such as JBIG, then performs RIP on the received data (decoded data if necessary), and executes printing. Such printing processing is executable only with respect to a printing request, which is transmitted from an apparatus capable of directly outputting data in a data format that is printable by the image forming apparatus 5007 specified in advance.
As described above, in order to perform printing, the image forming apparatus 5007, having means for directly connecting to the LAN 5001 and means for interpreting a printing language, interprets the printing data (printing language formed into a data packet), transmitted from a client, with the use of the interpretation means. In other words, the image forming apparatus is incapable of printing the printing data written in a printing language or data format that cannot be interpreted by the interpretation means.
On the contrary, the image forming apparatus 5002, not having means for directly connecting to the LAN 5001, can perform printing processing of various printing data written in various printing languages or data formats, by exchangeably utilizing the printer server 5003 for interpreting different printing languages.
However, in a case where the printer server 5003 is provided, the terminal apparatus 5009 cannot directly acquire from the image forming apparatus 5002 information related to the state and features of the image forming apparatus 5002. Furthermore, the image forming apparatus 5002 cannot voluntarily transmit information related to the state and features to the terminal apparatus 5009.

Method and apparatus for format conversion of printing data


An optical apparatus capable of a panoramic photographing includes a photographing lens, an auxiliary lens having positive refraction to convert its focal length synthesized with the photographing lens to a focal length shorter than the individual focal length of the photographing lens without changing the positions of an image formation, and an auxiliary lens supporting means which removably supports the auxiliary lens in the optical path between the photographing lens and the image-formation plane, and is constructed to perform easily a usual photographing individually with the photographing lens as well as a panoramic photographing with the installation of the auxiliary lens.

1. Field of the Invention
The present invention relates to an optical apparatus capable of photographing in a panoramic size. More particularly, the invention relates to an optical apparatus for photographing by switching a Leica size over to a panoramic size.
2. Related Background Art
A panoramic camera is a camera capable of taking a picture of a so-called panoramic size shown in FIG. 19A which is extremely long from side to side as compared with an ordinary picture, and is suited for photographing an extensive scene or the like. The panoramic camera has been in use for a long time. Nevertheless, amateur cameramen in general find it rather difficult to enjoy the panoramic photographing because photographic shops (the so-called labos) are not prepared usually to develop such a film, print it automatically, or perform other processings due to the special frame size of the film.
In recent years, however, a panoramic size film has been developed using a usual 35 mm film (JIS 135), the so-called Leica size of 24.times.36 as shown in FIG. 19B, for example. The panoramic size film, which is now in the spotlight among those who are in the art, is in a size of 13.times.36 mm such as obtainable by narrowing the frame size of the above-mentioned 35 mm film vertically as shown in FIG. 19C. Thus, by maintaining the dimension in the lateral direction the same as the Leica size, it becomes possible to perform the film development and printing with the conventional labo-equipment and instruments. At the same time, the so-called disposable camera dedicated for this type of panoramic film is now available in the market, promoting a rapid popularization thereof among the general amateur cameramen as a panoramic film which they can use without difficulty. In manufacturing a camera, this panoramic film also has an advantage that with the same dimension as the Leica size in the lateral direction, it is possible to implement with ease the camera which can be used both for the usual Leica size and the panoramic size by the use of a shade and others to narrow the exposure area of the film.
In other words, it is possible to implement easily a camera whereby a picture can be taken in the panoramic size by modifying the conventional camera slightly or incorporating some attachment therein. In fact, among camera dilettanti, there are some who modify the conventional 35 mm camera into a panoramic camera by shading the upper and lower parts of the longitudinal direction of the film aperture 10 of the camera body B with think flat shading members 20 as shown in FIG. 20. Recently, a kit for such a modification is commercially available on the market.
With this method, however, while the photographing can be performed in a panoramic size, the angle of view whereby a picture can be taken by a same camera beocmes narrow as compared with the usual state of its use. For example, whereas the photographing lens having its focal length of 35 mm in the Leica size has an angle of view of approximately 63.degree. with the diagonal line contained, the angle of view becomes approximately 57.degree. in the panoramic size, which is equivalent to a focal length of 40 mm in terms of the Leica size. This cannot be termed as a wide angle lens. Also, a lens having a focal length of 28 mm has an angle of view of 63.degree. likewise, but it has an angle of view of only approximately 57.degree. with the diagonal line contained in the panoramic size, which is equivalent to a focal length of 40 mm in terms of the Leica size. With this result, it cannot be said, either, that the angle of view of a wide angle lens has been utilized sufficiently. Also, likewise, a lens having a focal length of 28 mm has an angle of view of approximately 68.degree. with the diagonal line contained in the panoramic size, but it produces a narrow angle of view in the Leica size, which is equivalent to a focal length of 32 mm. As described earlier, the panoramic size is a format which is suited for performing a photographing in a wide area in the lateral direction. It is therefore a considerable disadvantage that the angle of view becomes narrower.
In order to avoid this disadvantage, a photographing lens having an extremely wide angle of view should be prepared in advance. In optical designing, however, the wider the angle of view is, the more difficult it is to design a lens, and it is also unavoidable to increase the manufacturing cost of the camera as a whole and to make the size thereof larger because the numbers of elements to construct a lens increase and the lens diameter becomes greater. Also, when a photographing lens to be installed is a single focus lens, the adoption of a lens having an excessively wide angle of view for the use of the panoramic size photographing may lead to a danger that general users find it difficult to use such a lens because the angle of view becomes wider in taking a picture in the usual Leical size. In addition, it should be mention that a photographing lens is used rather wastefully because with this method the upper and lower part of an objective image are simply shaded for the purpose and the angle of view genuine to such a photographing lens is not fully utilized.

Optical apparatus capable of performing a panoramic photographing