Provided are a semiconductor surface protecting method and surface protecting sheet employing a material having adequate conformability for irregularities on semiconductor wafer circuit sides and sufficient rigidity as a support during grinding, and which does not become fluid with repeated temperature increases. Also provided is a surface protecting sheet for protection of the circuit side in the step of back side grinding of a semiconductor wafer, the surface protecting sheet having a polymeric film material with a surface protecting layer thereon that may become fluid upon heating and which hardens upon exposure to radiation or upon heating.

Thinning (also referred to herein as "grinding") of semiconductor wafers has conventionally been accomplished by "back side grinding" methods whereby the circuit side of a wafer is protected with a surface protecting sheet and the back side opposite the circuit side is ground. The thicknesses of silicon wafers are generally 150 μm on an industrial level, but even thinner wafer thicknesses are desired. When wafers are ground to even smaller thicknesses, the phenomenon of unevenness of the ground surface (back side) due to irregularities on the circuit side, i.e., the phenomenon of transfer of the circuit pattern to the back side, becomes more notable. The cause of this back side transfer phenomenon is explained as follows. Presently employed pressure sensitive adhesive surface protecting sheets are limited in their ability to conform to the irregularities of the circuitry on a semiconductor wafer. As a result, gaps (air pockets) are created between the pressure-sensitive adhesive layer and the circuit side, such that the wafer is not directly supported by the pressure-sensitive adhesive (protective layer) in those areas. When the wafer is ground very thin, the wafer shifts in the vertical direction at the unsupported scribe lines (street) between the circuit die while compressing the air pockets with the result that the wafer is not ground in these areas, and remains thicker than the other portions. On the other hand, when hard protrusions such as bumps are present, the wafer is ground to a greater degree and thus becomes thinner than the other portions. This phenomenon is not a problem if the finished thickness is 150 μm or greater, but if the wafer is thinned to less than 100 μm (especially when finishing to a thickness of 50 μm or less), or if tall protrusions such as bumps are present on the wafer circuit side (for example, at 100 μm or greater), not only is the transverse strength of the wafer reduced considerably, but in severe cases the wafer can even be damaged during grinding. Also, when a wafer is thinly ground to about 50 μm edge chipping of the wafer or penetration of grinding water between the wafer and surface protecting layer can constitute a problem, but this has also been caused by a lack of adhesion of the surface protecting sheet to the wafer edges. In addition, with semiconductor wafers which are thin and also have bumps or other protrusions of 100 μm or greater on the circuit side, it is difficult to accomplish grinding by attachment of typical surface protecting sheets.
A conventional surface protecting sheet is usually a sheet having a pressure-sensitive adhesive layer as a surface protecting layer on a polymeric film material. The pressure-sensitive adhesive is designed so as to have a low elastic modulus in order to follow irregularities on the circuit side. If this tendency is too strong, however, the wafer can undergo considerable stress and suffer damage when the sheet is removed by peeling from the wafer. This has led to the development of energy beam peelable protecting sheets wherein the pressure-sensitive adhesive is hardened by irradiation with an energy beam such as ultraviolet rays to lower the adhesive strength between the wafer and protecting sheet before peeling. However, an often occurring problem is that the pressure-sensitive adhesive layer is too flexible in the unhardened state during grinding, and the wafer thus suffers damage during grinding.
Japanese Unexamined Patent Publication HEI No. 11-26404 discloses a wafer grinding method whereby the aforementioned energy beam peelable protecting sheet is attached to a circuit-formed wafer and the pressure-sensitive adhesive layer is hardened with an energy beam, after which the back side of the wafer is ground. However, since the pressure-sensitive adhesive is not fluid, its conformability against irregularities on the wafer circuit side is not adequate.
Japanese Unexamined Patent Publication No. 2000-38556 discloses a hot-melt semiconductor surface protecting sheet. The hot-melt sheet melts and exhibits fluid properties by heating at 60-100° C., and thus is able to conform to irregularities on the circuit side and exhibit excellent grinding properties. However, the sheet repeatedly melts when the temperature rises above the melting point. In most cases, a semiconductor wafer which has been laminated with a protective sheet is subjected to subsequent heating during lamination of a film used for attachment of chips, or a "die attachment film" (hereinafter referred to as "DAF"), or during a metal film forming step by sputtering. As a result, the temperature increase produced in such steps has caused problems including remelting of the protective sheet.


An optical orientation device includes a support structure; an optical element having an optical surface interacting with a laser beam; and a mechanism mounted on the support structure rotating the optical element around mutually perpendicular first and second fixed rotation axes. The mechanism includes a first rotary assembly articulated around a first mobile support axis, which is rotary and perpendicular relative to the first rotation axis. The first rotary assembly is coupled to the support structure to rotate around the first rotation axis, so the optical element rotates around the first rotation axis and the first mobile support axis. A second rotary assembly rotates around a second mobile support axis perpendicular to the first mobile support axis. The beam passes through a cavity around the first rotation axis, the cavity facing the optical element. First and second linear actuators rotate the first rotary assembly and the second rotary assembly, respectively.

In technical field of reference, devices are known, which are used for the orientation of an optical element. Especially, though not exclusively, these devices can be used for the motor-driven control of the direction of a beam of light in the space.
One of the possible fields of application of these devices is—for example—that of laser (micro)surgery.
In particular, in the technical field of reference, devices of the type mentioned above are known, which are manually operated, so as to orient—in the space—a mirror that causes the light beam to converge and points it based on its position.
This type of devices is affected by numerous drawbacks, like for example that of not being provided with a motor-driven system and that of not being able to be controlled in an assisted fashion by a processor. This leads to the drawback of not being able to improve surgical quality in terms of precision and safety, thus precluding the application of some techniques, such as the automatic execution of scanning motions, of tremor filtering, of motion scaling as well as the adoption of customized control interfaces.
U.S. Pat. No. 5,966,991 discloses the use of a two degree-of-freedom spherical orienting device, which comprises a mechanism, which is operated by a pair of rotary actuators, which, in turn, are fixed to a support structure. This concept was taken up, with some changes, also in the more recent patent publication EP 2 256 397 A1.
However, the aforesaid configurations of devices using rotary motors are affected by different drawbacks.
One drawback is due to the fact that they are not suited to be used in combination with optical elements that can be passed through by a light beam (also known as see-through elements), since the mechanisms used are provided with rotary assemblies that interfere with the trajectory of the incident light beam that is suited to interact with the optical element. In particular, known mechanisms are also affected by the drawback of obstructing—or being an obstacle for—the line of sight of an observer wanting to see through the optical element (typically, from the top to the bottom or, anyway, in a direction that is substantially orthogonal to the light beam).
A further drawback results from the fact that the rotation of the motors strictly depends on the gear ration chosen. For example, for given gear ratios, the precision in the positioning of the optical element can be very high, but, in this case, it decreases the maximum reachable speed, and vice versa.
DE 10 2012 012 780 A1 describes a mirror system to deflect a laser beam. The system described therein comprises a suspension device to support the mirror, so as to allow it to rotate around two orthogonal axes, and an operating device to move the mirror. The suspension device has a first inner frame, where the mirror is held so as to be able to rotate around a first axis, and a second outer frame, where the first inner frame is held so as to be able to rotate around a second axis. The operating device is provided with two linear actuator units, each coupled in an articulated and symmetrical manner relative to the other one. The two linear actuators are arranged at a distance from one another, substantially extend in parallel directions and can be controlled separately, so as to carry out a rotation of the mirror in a desired position.
However, even the system described in the prior art document discussed above is affected by the same drawbacks mentioned above.

Device for the spherical orientation of an optical element, in particular for directing a light beam, such as a laser beam

FONDAZIONE ISTITUTO ITALIANO DI TECNOLOGIA


An apparatus for diagnosing arteriosclerosis of a living subject, including an inflatable cuff which is adapted to be wound around a first portion of the subject to press the first portion with a pressing pressure, a pulse-wave detecting device which detects a pulse wave that is produced from an artery of the first portion of the subject pressed by the cuff with the pressing pressure and is transmitted to the cuff, and an arteriosclerosis judging device for judging, based on a change of the pulse wave caused by a change of the pressing pressure of the cuff, whether there is an arteriosclerotic lesion in a second portion of the subject that is located upstream of the first portion in a direction in which blood flows in the artery.

1. Field of the Invention
The present invention relates to an arteriosclerosis diagnosing apparatus for diagnosing arteriosclerosis or arteriosclerotic lesion, in particular, atherosclerosis.
2. Related Art Statement
There are known three sorts of arteriosclerosis; atherosclerosis is atheromatous sclerosis of endothelium of large or medium arteries, mediosclerosis is calcification of media of arteries, and arteriolosclerosis is sclerosis of small arteries.
Meanwhile, pulse-wave-propagation-velocity-related information that is related to a velocity at which a pulse wave propagates between two regions of a living subject, e.g., pulse-wave propagation velocity itself or pulse-wave propagation time, may be measured to diagnose whether the subject has atherosclerosis or not, or what degree of atherosclerosis the subject has. If a pulse-wave propagation velocity as a sort of pulse-wave-propagation-velocity-related information is measured from an atherosclerotic region of the subject, the measured velocity is higher than a normal velocity, if a degree of the atherosclerosis is low; and the measured velocity is lower than the normal velocity, if the degree of atherosclerosis is medium or high. Thus, the pulse-wave-propagation-velocity-related information can be used to diagnose whether the subject has atherosclerosis, or what degree of atherosclerosis the subject has.
The reason why a measured pulse-wave propagation velocity is higher than a normal velocity if a degree of atherosclerosis is low and the measured velocity is lower than the normal velocity if the degree of atherosclerosis is medium or high, is as follows: As atherosclerosis that is also called arteriostenosis advances, the inner diameters of arteries decrease. Since blood pressure lowers downstream of the arteriostenotic region, pulse-wave propagation velocity that changes with the blood pressure also lowers. Meanwhile, since mediosclerosis is calcification of media, the pulse-wave propagation velocity increases as the mediosclerosis advances. Generally, the mediosclerosis advances with the atherosclerosis. In the case where the degree of atherosclerosis is low, the influence of mediosclerosis is stronger than that of the atherosclerosis and accordingly the pulse-wave propagation velocity is higher than the normal velocity. However, in the case where the degree of atherosclerosis is medium or high, the influence of atherosclerosis is stronger than that of the mediosclerosis and accordingly the pulse-wave propagation velocity is lower than the normal velocity.
Pulse-wave propagation velocity has the above-described relationship with atherosclerosis and mediosclerosis. Since, however, the present invention relates to an apparatus for diagnosing atherosclerosis or arteriostenosis, the following description employs such a definition that arteriosclerosis means atherosclerosis, unless it otherwise specifies.
There is known an inferior-and-superior-limb blood-pressure-index measuring apparatus as a sort of arteriosclerosis diagnosing apparatus. This apparatus is disclosed in, e.g., Japanese Patent No. 3,140,007 or its corresponding U.S. Pat. No. 6,355,000. The inferior-and-superior-limb blood-pressure-index measuring apparatus includes two cuffs that are adapted to be worn on an inferior limb and a superior limb of a living subject, calculates, as an inferior-and-superior-limb blood-pressure-index, a ratio of one of a superior-limb blood pressure and an inferior-limb blood pressure to the other, and diagnoses arteriosclerosis based on the thus calculated inferior-and-superior-limb blood-pressure-index. If this apparatus is so modified as to be able to obtain pulse-wave-propagation-velocity-related information so as to assure the reliability of inferior-and-superior-limb blood-pressure-index, then the apparatus would be able to more accurately diagnose arteriosclerosis. If the two cuffs employed to measure the superior-limb blood pressure and the inferior-limb blood pressure are used to detect respective pulse waves from the superior limb and the inferior limb, the thus detected two pulse waves would be able to be used to determine a pulse-wave propagation time. Thus, the pulse-wave propagation time as another sort of pulse-wave-propagation-velocity-related information would be able to be obtained without needing to employing any additional sensors.
In many cases, arteriosclerosis occurs to inferior limbs only. However, in some cases, arteriosclerosis occurs to superior limbs as well. A pulse-wave propagation time measured from a superior limb and an inferior limb means a difference between a time of propagation of a pulse wave from the heart to the superior limb and a time of propagation of the pulse wave from the heart to the inferior limb. Therefore, in those cases, even if the inferior limb has arteriosclerosis and accordingly a time of propagation of pulse wave from the heart to the inferior limb increases, a pulse-wave propagation time measured from the superior limb and the inferior limb, or a pulse-wave propagation velocity determined based on the measured propagation time falls in a normal range, if the superior limb has arteriosclerosis and accordingly a time of propagation of pulse wave from the heart to the superior limb increases. Thus, in the above-indicated cases, the pulse-wave-propagation-velocity-related information obtained from the superior and inferior limbs cannot be used to diagnose arteriosclerosis with high accuracy.
Meanwhile, there are some cases where noise produced by a physical motion of a living subject is mixed with pulse waves and accordingly respective reference points of those pulse waves that are to be used to obtain pulse-wave propagation-velocity-related information cannot be accurately detected. In those cases, the pulse-wave-propagation-velocity-related information cannot be obtained with accuracy. In addition, if arrhythmia occurs to a living subject, respective reference points of two pulse waves to be used to obtain pulse-wave propagation-velocity-related information may not be accurately detected, and accordingly the pulse-wave-propagation-velocity-related information may not be obtained with accuracy. If pulse-wave-propagation-velocity-related information cannot be obtained with accuracy, then arteriosclerotic legion cannot be diagnosed with accuracy.
It is therefore an object of the present invention to provide an arteriosclerosis diagnosing apparatus for diagnosing arteriosclerosis or arteriosclerotic lesion with high accuracy.
The above object has been achieved by the present invention. According to a first aspect of the present invention, there is provided an apparatus for diagnosing arteriosclerosis of a living subject, comprising an inflatable cuff which is adapted to be wound around a first portion of the subject to press said first portion with a pressing pressure; a pulse-wave detecting device which detects a pulse wave that is produced from an artery of said first portion of the subject pressed by the cuff with the pressing pressure and is transmitted to the cuff; and an arteriosclerosis judging means for judging, based on a change of the pulse wave caused by a change of the pressing pressure of the cuff, whether there is an arteriosclerotic lesion in a second portion of the subject that is located upstream of said first portion in a direction in which blood flows in the artery.
If the subject has arteriosclerosis in the second portion located upstream of the first portion around which the cuff is wound, the sharpness of shape of the pulse wave detected from the first portion by the pulse-wave detecting device significantly decreases at a lower pressing pressure of the cuff than a pressing pressure at which the sharpness of shape of a pulse wave detected from a first portion located downstream of a second portion free of arteriosclerosis significantly decreases. Therefore, the arteriosclerosis judging means can judge, based on the change of the pulse wave caused by the change of the pressing pressure of the cuff, whether there is arteriosclerosis in the second portion located upstream of the first portion around which the cuff is wound.
If the above-described principle is applied to the left and right superior limbs, arteriosclerosis of an inferior limb can be accurately diagnosed based on pulse-wave-propagation-velocity-related information obtained from the inferior limb and one of the two superior limbs. According to a second aspect of the present invention, there is provided an apparatus for diagnosing arteriosclerosis of an inferior limb of a living subject, comprising a left-superior-limb cuff which is adapted to be wound around a left superior limb of the subject to press the left superior limb with a first pressing pressure; a right-superior-limb cuff which is adapted to be wound around a right superior limb of the subject to press the right superior limb with a second pressing pressure; an inferior-limb cuff which is adapted to be wound around the inferior limb of the subject; a left-superior-limb pulse-wave detecting device which detects, as a left-superior-limb pulse wave, a pulse wave which is produced from an artery of the left superior limb pressed by the left-superior-limb cuff with the first pressing pressure and is transmitted to the left-superior-limb cuff; a right-superior-limb pulse-wave detecting device which detects, as a right-superior-limb pulse wave, the pulse wave which is produced from an artery of the right superior limb pressed by the right-superior-limb cuff with the second pressing pressure and is transmitted to the right-superior-limb cuff; an inferior-limb pulse-wave detecting device which detects, as an inferior-limb pulse wave, the pulse wave which is produced from an artery of the inferior limb pressed by the inferior-limb cuff and is transmitted to the inferior-limb cuff; a change-value calculating means for calculating a first change value representing a change of the left-superior-limb pulse wave caused by a change of the first pressing pressure of the left-superior-limb cuff, and a second change value representing a change of the right-superior-limb pulse wave caused by a change of the second pressing pressure of the right-superior-limb cuff; an arteriosclerosis judging means for judging, based on a comparison of the first and second change values calculated by the change-value calculating means, which is lower, a degree of arteriosclerosis of a first portion of the subject located between the heart of the subject and the left superior limb or a degree of arteriosclerosis of a second portion of the subject located between the heart and the right superior limb; and a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on (a) one of the left-superior-limb pulse wave and the right-superior-limb pulse wave that corresponds to one of the first and second portions that has the degree of arteriosclerosis judged as being lower than the degree of arteriosclerosis of the other of the first and second portions by the arteriosclerosis judging means, and (b) the inferior-limb pulse wave detected by the inferior-limb pulse-wave detecting device, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.
According to this aspect, the change-value calculating means calculates the first and second change values. The first change value represents the change of the left-superior-limb pulse wave caused by the change of the first pressing pressure of the left-superior-limb cuff, and the second change value represents the change of the right-superior-limb pulse wave caused by the change of the second pressing pressure of the right-superior-limb cuff. Thus, the first change value reflects a degree of arteriosclerosis of the first portion of the subject located between the heart and the left superior limb, and the second change value reflects a degree of arteriosclerosis of the second portion of the subject located between the heart and the right superior limb. Therefore, the arteriosclerosis judging means can judge, by comparing the first and second change values with each other, which is lower, the degree of arteriosclerosis of the first portion located between the heart and the left superior limb or the degree of arteriosclerosis of the second portion located between the heart and the right superior limb. The pulse-wave-propagation-velocity-related-information obtaining means obtains, based on the superior-limb pulse wave corresponding to one of the first and second portions that has the degree of arteriosclerosis judged as being lower by the arteriosclerosis judging means, and the inferior-limb pulse wave, the pulse-wave-propagation-velocity-related information. Thus, the present apparatus can obtain the pulse-wave-propagation-velocity-related information that is less influenced by the arteriosclerosis of the superior limbs. Therefore, the pulse-wave-propagation-velocity-related information can be used to diagnose accurately arteriosclerosis of the inferior limb.
According to a third aspect of the present invention, there is provided an apparatus for diagnosing arteriosclerosis of a living subject, comprising a first-pulse-wave detecting device including a first detecting portion which is adapted to be worn on a first body portion of the subject to detect, as a first pulse wave, a pulse wave produced from the first body portion; a second-pulse-wave detecting device including a second detecting portion which is adapted to be worn on a second body portion of the subject to detect, as a second pulse wave, the pulse wave produced from the second body portion; a synchronism judging means for judging whether the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device are synchronous with each other; and a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on the first and second pulse waves judged as being synchronous with each other by the synchronism judging means, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.
When noise is produced by a physical motion of the living subject, it may be mixed, at different timings, with two pulse waves detected from different regions of the subject. In this case, respective detected pulses of the two pulse waves may not be synchronous with each other. However, if the synchronism judging means judges that first pulse wave detected by the first pulse-wave detecting device and the second pulse wave detected by the second pulse-wave detecting device are synchronous with each other, then it can be said that the first and second pulse waves are free of the noise produced by the physical motion of the subject. The pulse-wave-propagation-velocity-related-information obtaining means obtains the pulse-wave-propagation-velocity-related information based on the first and second pulse waves judged as being synchronous with each other by the synchronism judging means. Thus, the present apparatus can obtain accurate pulse-wave-propagation-velocity-related information. Therefore, arteriosclerosis can be accurately diagnosed based on the thus obtained, accurate pulse-wave-propagation-velocity-related information.
According to a fourth aspect of the present invention, there is provided an apparatus for diagnosing arteriosclerosis of a living subject, comprising a first-pulse-wave detecting device including a first detecting portion which is adapted to be worn on a first body portion of the subject to detect, as a first pulse wave, a pulse wave produced from the first body portion; a second-pulse-wave detecting device including a second detecting portion which is adapted to be worn on a second body portion of the subject to detect, as a second pulse wave, the pulse wave produced from the second body portion; a normal-pulse-period-range determining means for determining a normal pulse-period range based on one of the first pulse wave detected by the first-pulse-wave detecting device and the second pulse wave detected by the second-pulse-wave detecting device; an arrhythmia judging means for judging, when one of a pulse period of the first pulse wave and a pulse period of the second pulse wave falls in the normal pulse-period range determined by the normal-pulse-period-range determining means, that the first and second pulse waves are not arrhythmic; and a pulse-wave-propagation-velocity-related-information obtaining means for obtaining, based on the first and second pulse waves judged as being not arrhythmic by the arrhythmia judging means, pulse-wave-propagation-velocity-related information that is related to a velocity at which the pulse wave propagates in the subject.
According to this aspect, the pulse-wave-propagation-velocity-related-information obtaining means obtains the pulse-wave-propagation-velocity-related information based on the first and second pulse waves judged as being not arrhythmic by the arrhythmia judging means. Thus, the present apparatus can obtain accurate pulse-wave-propagation-velocity-related information. Therefore, arteriosclerosis can be accurately diagnosed based on the thus obtained, accurate pulse-wave-propagation-velocity-related information.


A water-dissipatable polymer having colorant attached thereto through a covalent xe2x80x94O-link and an ink comprising the water-dissipatable polymer and a liquid medium.

This invention relates to coloured water-dissipatable polymers, to inks containing the coloured water-dissipatable polymers and to their use in ink jet printing.
Ink jet printing methods involve a non-impact printing technique for printing an image onto a substrate using ink droplets ejected through a fine nozzle onto a substrate without bringing the nozzle into contact with the substrate.
There are many demanding performance requirements for colorants and inks used in ink jet printing. For example they desirably provide sharp, non-feathered images having good water-fastness, light-fastness and optical density. The inks are often required to dry quickly when applied to a substrate to prevent smudging, but they should not form a crust over the tip of an ink jet nozzle because this will stop the printer from working. The inks should also be stable to storage over time without decomposing or forming a precipitate which could block the fine nozzle. The most popular ink jet printers are thermal and piezoelectric ink jet printers.
There is a need for inks which are suitable for both thermal and piezo ink jet printers, have high colour strength and produce images having a high light-fastness and water-fastness when printed on a substrate.
We have surprisingly found that the coloration of water-dissipatable polymers having hydroxy functional groups by reacting the hydroxy functional groups with a colorant, a bridging group for a colorant or a colorant precursor and further reaction of the bridging compound with a colorant or colorant precursor and subsequent conversion of the colorant precursor to a colorant, gives a coloured water-dissipatable polymer which is suitable for use in inks for thermal and piezo ink jet printers.
According to a first aspect of the present invention there is provided a water-dissipatable polymer having colorant attached thereto through a covalent xe2x80x94O-link.
A xe2x80x94O-link may be exemplified by but is not limited to the following links such as an ether link (R1xe2x80x94Oxe2x80x94R2, an ester link (R1xe2x80x94Oxe2x80x94C(O)xe2x80x94R2) and a phosphate ester link (R1xe2x80x94Oxe2x80x94P(O)(OH)xe2x80x94R2), where R1 represents the water-dissipatable polymer and R2 represents the colorant.
A water-dissipatable polymer of the invention is obtainable by attaching a colorant to a water-dissipatable polymer having hydroxy functional groups by means of a reaction between the hydroxy functional groups on the polymer with a colorant having a functional group capable of reacting with the hydroxy functional group.
The colorant may also be attached to the water-dissipatable polymer by means of a reaction between a hydroxy group on the polymer with a colorant precursor thereby forming a covalent bond therebetween and subsequently converting the colorant precursor to a colorant.
Alternatively, colorants may be grafted to the water-dissipatable polymer via a bridging compound. For example, colorant may be attached to the water-dissipatable polymer by means of a reaction between the hydroxy functional group on the water-dissipatable polymer with a bridging compound thereby forming a covalent bond therebetween and subsequently reading the bridging compound with a colorant or colorant precursor. The bridging agent may be a di-, tri-, tetra- or polyfunctional structure, and examples include, but are not limited to bis alkyl halides, tris dialkyl halides, bis acid chlorides, tris dia chlorides, bis vinyl sulphones, tris divinyl sulphones, mixtures of alkyl halides and acid chlorides, michael acceptors, cyanuric chloride and related reactive 1,3,5-triazines, other reactive heterocyclic halides and aromatic halides. Most preferably cyanuric chloride is used.
The water-dissipatable polymer of the invention is preferably prepared by condensing a water-dissipatable polymer having hydroxy functional groups with a colorant having a functional group reactive towards the hydroxy functional groups. Such functional groups are described above. Up to 100%, preferably at least 95%, more preferably at least 90%, most preferably at least 85% of the hydroxy functional groups are reacted with the colorant. The condensation is performed by preparing a solution or suspension of a water-dissipatable polymer having hydroxy functional groups in an aqueous and/or non-aqueous solvent. Preferably the condensation is performed at a pH of 5 to 14, more preferably of 6 to 13, especially of 7 to 12. The condensation is preferably performed in the presence of an inorganic or organic base. Preferred inorganic bases are NaOH, KOH, Na2CO3, K2CO3. Preferred organic bases are trialkyl amines, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 1,4-diazabicyclo[2.2.2]octane (DABCO). Subsequently an aqueous solution of a colorant is added to the suspension and the mixture is stirred until the reaction is complete.
Alternatively a non-aqueous grafting reaction can be used to react the water-dissipatable polymer having hydroxy functional groups with a colorant. The colorant and polymer are stirred in a non-aqueous solvent with a base (either homogeneous or heterogeneous) and heated as required to complete the reaction. In the case of ester formation, for example reacting an acid functionalised colorant (e.g. phosphoric acid functionalised) and the water-dissipatable polymer having hydroxy functional groups, conditions are required to remove the generated water either physically (e.g. by azeotroping, molecular sieves) or chemically using a dehydrating agent such as dicyclohexylcarbodiimide or dicyandiamide. Acid catalysts such as p-toluenesulphonic acid or sulphuric acid may also be employed.
The water-dissipatable polymer of the invention may be isolated from the aqueous system by either acidification and filtration; dilution with a water miscible solvent and filtration, salting out with organic salts or solutions of organic salts or combinations of these methods. Suitable salts include sodium chloride, ammonium chloride, sodium sulphate and lithium chloride. Alternatively the mixture is acidified until the water-dissipatable polymer of the invention precipitates out or the solvent is evaporated or the solvent is diluted with water until the water-dissipatable polymer of the invention precipitates out.
Alternatively the water-dissipatable polymer of the present invention may be purified by ion-exchange methods on cationic resins. Other options include the removal of low molecular weight materials such as co-solvents used for the polymerisation, low molecular weight salts, impurities and free monomers by ultra-filtration, osmosis, reverse osmosis, dialysis, ultra-filtration or a combination thereof, followed by evaporation of the water.
Preferably the number average molecular weight (Mn) of the water-dissipatable polymer used to make the polymer of the invention is less than 25,000, more preferably is less than 20,000, especially less than 15,000. The Mn of the polymer may be measured by gel permeation chromatography (xe2x80x9cgpcxe2x80x9d).
The gpc method used for determining Mn preferably comprises applying the polymer to a chromatography column parked with cross-linked polystyrene/divinyl benzene, eluting the column with tetrahydrofuran at a temperature of 40xc2x0 C. and assessing the Mn of the polymer compared to a number of a polystyrene standards of a known Mn. Suitable cross-linked polystyrene/divinyl benzene chromatography columns are commercially available from Polymer Laboratories.
As an alternative to the gpc method for determining Mn, the Mn may be determined using for example by multi-angle light scattering (MALLS).
The water-dissipatable polymer may be a copolymer, for example a random, alternating or block copolymer, preferably a random copolymer.
The water-dissipatable polymer may be a polyurethane, polyester or an olefinic polymer. Preferably the water-dissipatable polymer is an olefinic polymer. An olefinic polymer is a polymer obtainable from the polymerisation of one or more olefinically unsaturated monomers.
The water-dissipatable olefinic polymer is preferably obtainable from the polymerisaton of one or more olefinically unsaturated monomers having hydroxy functional groups, and one or more olefinically unsaturated monomers having water-dispersing groups optionally in the presence of one or more olefinically unsaturated monomers which are free from water-dispersing groups.
Preferred olefinically unsaturated monomers having hydroxy functional group(s) include, but are not limited to, hydroxy-functional esters of acrylic acid, methacrylic acid, maleic acid, or fumaric acid. Examples of such monomers include hydroxy functional alkyl (preferably 1 to 18 C) (meth)acrylates such as 2-hydroxy ethylacrylate, 2-hydroxy ethylmethacrylate, 2-hydroxy propylacrylate, 3-hydroxy propylacrylate, 2-hydroxy propylmethacrylate, 3-hydroxy propylmethacrylate, 4-hydroxy butylacrylate, 4-hydroxy butylmethacrylate, hydroxy stearylacrylate, hydroxy stearylmethacylate; dihydroxy alkyl (preferably 1 to 6 C) adducts of maleic acid, fumaric acid, and phthalic acid; polyethylene oxide or polypropylene oxide functionalised hydroxyl functional (meth)acrylate such as the commercially available material known as BISOMER PPM5S, BISOMER PPM6E (International Specialty Chemicals); Caprolactone acrylate monomers such as the commercial available material known as TONE M100 Monomer (Union Carbide). Other examples include (4-hydroxymethyl cyclohexyl)-methylacrylate (Mitsubishi Chemical); and Blemmer PE-90, Blemmer PE-200, and Blemmer PE-350 (polyethylene glycol methacylates of molecular weights 163-173, 261-303 and 387-468 respectively); Blemmer 70 PEP-350B (CH2xe2x95x90C(CH3xe2x80x94C(xe2x95x90O)xe2x80x94(EO), (PO)3)xe2x80x94H where EO is polyethylene oxide, PO is polypropylene oxide and the molecular weight is about 450); and Blemmer-GLM (glycerol dimethacrylate) (all Nippon Oil and Fats Co.); N-methylol acrylamide, glycerol monomethacrylate and trimethylol propane mono methacylate.
Olefinically unsaturated monomers having a hydroxy functional group also includes olefinically unsaturated monomers having a group which is convertible to a hydroxy functional group and include but are not limited to vinyl acetate, vinyl benzoate, vinyl benzyl chloride, vinyl bromide and vinyl chloride.
Water-dispersing groups provide the facility of self-dispersibility and solubility to the polymer in ink media, especially in water. The water-dispersing groups may be ionic, non-ionic or a mixture of ionic and non-ionic water-dispersing groups. Preferred ionic water-dispersing groups include basic amine groups, cationic quaternary ammonium groups and acid groups, for example phosphoric acid groups, sulphonic acid groups and carboxylic acid groups.
The water-dispersing groups may be incorporated into the polymer in the form of monomers or oligomers bearing the appropriate water-dispersing groups. One may also react a polymer which is not water-dissipatable with monomers or oligomers which make the polymer water-dissipatable.
The nature and level of water-dispersing groups in the polymer influences whether a solution, dispersion, emulsion or suspension is formed on dissipation of the water-dissipatable polymer.
The water-dispersing group content of the water-dissipatable polymer may vary within wide limits but is preferably sufficient to make the water-dissipatable polymer form stable ink-jet printing inks in water and aqueous media.
The acid water-dispersing groups may be subsequently fully or partially neutralised with a base containing a cationic charge to give a salt. If the acid water-dispersing groups are used in combination with a non-ionic water-dispersing group, neutralisation may not be required. The conversion of any free acid groups into the corresponding salt may be effected during the preparation of the water-dissipatable polymer and/or during the preparation of an ink from the water-dissipatable polymer.
Preferably the base used to neutralise any acid water-dispersing groups is ammonia, an amine or an inorganic base. Suitable amines are tertiary amines, for example triethylamine or triethanolamine. Suitable inorganic bases include alkaline hydroxides and carbonates, for example lithium hydroxide, sodium hydroxide, or potassium hydroxide. A quaternary ammonium hydroxide, for example N+(CH3)4OHxe2x88x92, can also be used. Generally a base is used which gives the required counter ion desired for the ink which is prepared from the polymer. For example, suitable counter ions include Li+, Na+, K+, NH4+ and substituted ammonium salts.
Preferred olefinically unsaturated monomers providing ionic water-dispersing groups include acrylic acid, methacrylic acid, itaconic acid, maleic acid, monoalkyl itaconates (for example, monomethyl maleate, monoethyl maleate, monobutyl maleate and monooctyl maleate), citraconic acid, styrenesulfonic acid, vinylbenzylsulfonic acid, vinylsulfonic acid, acryloyloxyalkyl sulfonic acids (for example, acryloyloxymethyl sulfonic acid, acryloyloxyethyl sulfonic acid, acryloyloxypropyl sulfonic acid and acryloyloxybutyl sulfonic acid), methacryloyloxymethyl sulfonic acid, methacryloyloxyethyl sulfonic acid, methacryloyloxypropyl sulfonic acid and methacryloyloxybutyl sulfonic acid), 2-acrylamido-2-alkylalkane sulfonic acids (for example 2-acrylamido-2-nethylethanesulfonic acid, 2-acrylamido-2methylpropanesulfonic acid and 2-acrylamido-2-methylbutane sulfonic acid), 2-methacrylamido-2-alkylalkane sulfonic acids (for example, 2-methacrylamido-2-methylethanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid and 2-methacrylamido-2-methylbutanesulfonic acid), mono-(acryloyloxyakyl)phosphates (for example, mono(acryloyloxyethyl)phosphate and mono(3-acryloyloxypropyl)phosphates) and mono(methacryloyloxyalkyl)phosphates (for example, mono(methacryloyloxyethyl)phosphate and mono(3-methacryloyloxypropylphosphate).
Non-ionic water-dispersing groups may be in-chain, pendant or terminal groups. Preferably non-ionic water-dispersing groups are pendant polyoxyalkylene groups, more preferably polyoxyethylene groups. The non-ionic water-dispersing groups may be introduced into the water-dissipatable polymer in the form of a compound bearing non-ionic water-dispersing groups and at least one (although preferably only one) copolymerisable olefinically unsaturated group.
Preferred olefinically unsaturated monomers providing non-ionic water-dispersing groups include alkoxy polyethylene glycol (meth)acrylates, preferably having a number average molecular weight of from 350 to 2000. Examples of such monomers which are commercially available include xcfx89-methoxypolyethylene glycol (meth)acrylate and diethylene glycol mono vinyl ether.
In addition to the water-dissipatable polymer comprising olefinically unsaturated monomers having a hydroxy functional group or a group which is convertible to a hydroxy functional group, and one or more olefinically unsaturated monomers having water-dispersing groups, the water-dissipatable polymer may also contain one or more olefinically unsaturated monomers which are free from water-dispersing groups and/or hydroxy functional groups.
Preferred olefinically unsaturated monomers which are free from water-dispersing groups include alkyl(meth)acrylates, optionally substituted styrenes, methacrylamides, allyl compounds, dienes, vinyl ethers, vinyl ketones, vinyl halides, vinylidene halides, olefins and unsaturated nitriles.
Preferred alkyl(meth)acrylates contain less than twenty carbon atoms. Examples include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl, sec-butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, tert-octyl acrylate, 2-phenoxyethyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrytate, 4-chlorobutyl acrylate, cyanoethyl acrylate, 2-acetoxyethyl acrylate, dimethylaminoethyl acrylate, benzyl acrylate, methoxybenzyl acrylate, 2-chlorocyclohexyl acrylate, acylate, cyclohexyl acylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, 5-hydroxypentyl acrylate, 2,2-dimethyl-3-hydoxypropyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, 2-ethoxyethyl acrylate, 2-iso-propoxyethyl acrylate, 2-butyoxyethyl acrylate, 2-(2-methoxyethoxy)ethyl acrylate, 2-(2-butoxyethoxy)ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate benzylmethacrylate, chlorobenzyl methacrylate, octyl methacrylate, N-ethyl-N-phenylaminoethyl methacrylate, 2-(3phenylpropyloxy)ethyl methacrylate, dimethylaminophenoxyethyl methacrylate and furfuryl methacrylate. Aromatic examples include but are not limited to 4-alkyl phenylacrylate or methacrylate, phenyl methacrylate, phenyl acrylate, and xcex2-napthyl methacrylate,
Preferred optionally substituted styrenes include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyene, bromostyrene, dibromostyrene, iodostyrene, trifluorostyrene and 2-bromo-4-tri-fluoromethylstyrene.
Preferred methacrylamides contain less than 12 carbon atoms. Examples include methylmethacrylamide, tert-butylmethacrylamide, tert-octylmethacrylamide, benzylmethacrylamide, cyclohexylmethacylamide, phenylmethacrylamide, dimethylmetharylamide, dipropylmethacrylamide, hydroxyethyl-N-methylmethacrylamide, N-methylphenylmethacrylamide, N-ethyl-N-phenylmethacrylamide and methacrylhydrazine.
Preferred allyl compounds include allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, allyloxyethanol, allyl butyl ether and allyl phenyl ether.
Preferred vinyl ethers contain less than 20 carbon atoms. Examples include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether and dimethylaminoethyl vinyl ether.
Preferred vinyl ketones contain less than 12 carbon atoms. Examples include methyl vinyl ketone, phenyl vinyl ketone and methoxyethyl vinyl ketone.
Preferred vinyl halides include vinyl chloride, vinylidene chloride and chlorotrifluoro ethylene.
Preferred olefins include unsaturated hydrocarbons having less than 20 carbon atoms. Examples include dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 5-methyl-1-nonene, 5,5-dimethyl-1-octene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 5-methyl-1-hexene, 4-methyl-1-heptene, 5-methyl-1-heptene, 4,4-dimethyl-1-hexene, 5,5,6-trimethyl-1-heptene, 1-dodecene and 1-octadecene.
Preferred unsaturated nitrites include arylonitrile and methacyrlonitrile.
The preferred olefinically unsaturated monomers which are free from water-dispersing groups are the alkyl (meth)acrylates containing less than 20 carbon atoms, especially those specifically listed above.
Preferably the water-dissipatable olefinic polymer is an acrylic polymer. An acrylic polymer is preferably a polymer formed from a monomer system comprising at least 40 weight % (more preferably at least 50 weight %) of one or more monomers of formula
CH2xe2x95x90CR2COOR3
where R2 is H or methyl and ZR3 is optionally substituted alkyl of 1 to 12 carbon atoms or cycloalkyl of 5 to 12 (more preferably 1 to 8 and 5 to 8 carbon atoms respectively), examples of which have been given herein.
The water-dissipatable olefinic polymer may be prepared in a conventional manner by polmerising the olefinically unsaturated monomers having water-dispersing groups and olefinically unsaturated monomers having a hydroxy functional group or a group which is convertible to a hydroxy functional group, either alone or in the presence of olefinically unsaturated monomers which are free from water-dispersing and hydroxy functional groups. Temperatures of from 20xc2x0 C. and 180xc2x0 C. are preferred. The polymerisation may be continued until reaction between the monomers is complete.
In one embodiment the olefinic water-dissipatable polymer may be prepared by polymerising an acrylic oligomer having water-dispersing groups and at least one olefinically unsaturated terminal group in the presence of one or more olefinically unsaturated monomers having a hydroxy functional group or a group which is convertible to a hydroxy functional group, and optionally one or more olefinically unsaturated monomers which are free from water-dispersing groups and/or one or more olefinically unsaturated monomers having water-dispersing groups.
Alternatively an acrylic oligomer with at least one olefinically unsaturated terminal group and which is free from water-dispersing groups may be polymerised in the presence of one or more olefinically unsaturated monomers having a hydroxy functional group or a group which is convertible to a hydroxy functional group and one or more olefinically unsaturated monomers having water-dispersing groups.
Preferred polymerisation methods include solution polymerisation, emulsion polymerisation, suspension polymerisation and solution/dispersion polymerisation and such general methods as are well known in the art. More preferably aqueous or non-aqueous solution polymerisation and emulsion polymerisation is used and most preferably solution polymerisation is used.
If desired, an initiator may be used to assist the water-dissipatable olefinic polymer formation. Suitable initiators are free-radical generators. Examples of catalysts include azobis compounds, peroxides, hydroperoxides, redox catalysts, etc., for example, potassium persulfate, ammonium persulfate, tert-butyl peroctoate, benzoyl peroxide, isopropyl percarbonate, 2,4-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, azobisisobutyronitrile, azobis(2-amidino-propane)hydrochloride and the like.
Typically 0.05 to 5% by weight of initiator is used relative to the total weight of the monomers. Preferably the polymerisation is performed in the presence of an emulsifying agent.
The molecular weight of the olefinic water-dissipatable polymer may be controlled by the addition of chain transfer agents and/or through the adjustment of the ration of the concentration of monomers relative to the concentration of initiator during the course of the polymerisation. Typical chain transfer agents are thiols, halocarbons and cobalt macrocycles.
When the water-dissipatable polymer is a polyester or polyurethane it may be prepared by conventional techniques, for example as described in WO99/50364 (polyurethanes) or WO98/59007 (polyesters) using a monomer carrying a protected hydroxy functional group to form the water-dissipatable polymer followed by removal of the protecting group prior to reaction with a colorant, a colorant precursor, or a bridging compound to give a covalent xe2x80x94O-link.
When the water-dissipatable polymer is prepared by the polymerisation of (a) monomers having hydroxy functional groups or a group which is convertible to a hydroxy functional group, and (b) monomers providing water-dispersing groups optionally in the presence of (c) monomers which are free from water-dispersing groups and hydroxy functional groups, it is preferred that the amount of (a) is from 1 to 95%, more preferably from 2 to 90% and the amount of (b) is from 1 to 95%, more preferably from 5 to 90% and the amount of (c) is from 0 to 95%, more preferably from 5 to 90% by weight, wherein (a)+(b)+(c) add up to 100.
The water-dissipatable polymer preferably has an acid value of from 0 to 750 mgKOH/g, more preferably 50 to 450 mgKOH/g, especially 50 to 225 mgKOH/g.
Suitable colorants include reactive dyes. Reactive dyes are known in the art as dyes as having functional groups reactive towards hydroxy functional groups. These reactive dyes include, but are not limited to: i) chlorine or fluorine containing reactive dyes, for example dichloro and monochloro triazine reactive dyes, ii) vinyl sulphone or protected vinyl sulphone reactive dyes for example sulphato ethyl sulphone reactive dyes, iii) aziridine functionalised dyes, iv) epoxide functionalised dyes, v) isocyanate functionalised dyes and vi) phosphoric acid functionalised dyes which give ester links on dehydration.
The colorant preferably has at least one functional group capable of reacting with a hydroxy functional group on the water-dissipatable polymer. If two or more such functional groups are present in the colorant, one preferably has a higher reactivity than the other(s) to prevent undesirable cross-linking which results in a non-desirable viscosity increase, making the water-dissipatable polymer less suitable for thermal ink-jet printing inks. Examples of suitable functional groups include alkyl halides, acid chlorides or bromides, reactive aryl and heterocyclic halides, esters, acids (if a catalyst and/or a dehydrating agent is used), reactive olefins and masked reactive olefins (for example vinyl sulphones or acrylates), isocyanates, isothiocyanates, epoxides, aziridenes, tosylates, mesylates and other sulphone leaving groups. The functional group may be present in the colorant or grafted to the colorant via a bridging compound.
The colorant preferably has a chromophoric group comprising an azo, anthraquinone, pyrroline, phthalocyanine, polymethine, aryl-carbonium, triphenodioxazine, benzodifuranone or indolene group. Preferred chromophoric groups are azo groups, especially monoazo, disazo, tisazo and phthalocyanine groups.
The colorant may be a single coloured component or a mixture of coloured components, for example it may be a mixture of different dyes. By using a mixture of different dyes as the colorant one may achieve greater flexibility in colour of the ink. The colorant may also comprise a colorant precursor. For example the colorant precursor may be converted to a colorant by a process comprising a diazotisation reaction. A diazotisation reaction suitably comprises the steps:
(i) diazotising an amino group in the colorant precursor using a diazotising agent; and
(ii) coupling the product of step (i) with a coupling component forming an azo group therebetween.
Preferably the colorant is soluble in organic solvents and/or water, especially water. More preferably the dyes are water soluble anionic or catonic dyes. Most preferably an anionic dye is used to graft onto an anionic water-dissipatable polymer and a cationic dye is used to graft onto a cationic water-dissipatable polymer. Water solubility of the dye may be achieved by the presence of acidic or basic groups in the dye. Preferred acidic groups are phosphonic, carboxylic or sulphonic acids, and combinations and salts thereof.
In a second aspect of the present invention there is provided an ink comprising the components:
(a) a water-dissipatable polymer according to the first aspect of the present invention; and (b) a liquid medium.
Preferably the ink comprises from 0.5 to 50 parts of component (a) and from 50 to 99.5 parts of component (b), wherein all parts are by weight and the number of parts of (a)+(b)=100. The number of parts of component (a) is preferably from 0.5 to 28, more preferably from 2 to 25, and especially from 2.5 to 20 parts. Preferably component (b) comprises water and an organic solvent. More preferably component (b) comprises from 40 to 95 parts, more preferably from 50 to 90 parts of water; and from 2 to 60 parts, more preferably from 3 to 50 parts, especially from 5 to 35 parts of water-miscible organic solvent. Preferably component (a) is completely dissipated in component (b).
The number of parts of component (a) (the water-dissipatable polymer of the invention) is calculated on a 100% solids basis. For example 50 g of a water-dissipatable polymer of the invention in a 20% solids w/w dispersion is taken as 10 g of component (a).
The inks according to the second aspect of the invention may be prepared by mixing the water-dissipatable polymer of the invention with a liquid medium. Suitable techniques are well known in the art, for example agitation, ultrasonication or stirring of the mixture. The mixture of water-dissipatable polymer of the invention and liquid medium may be in the form of a dispersion, emulsification, suspension, solution or mixture thereof.
The liquid medium is preferably water, a mixture of water and an organic solvent and an organic solvent free from water. For example the water-dissipatable polymer of the invention may be added to water followed by the addition of one or more organic solvents. Preferably the water-dissipatable polymer of the invention is mixed with a liquid medium, comprising a mixture of water and one or more organic solvents.
When the liquid medium comprises a mixture of water and an organic solvent, the weight ratio of water to organic solvent is preferably from 99:1 to 1:99, more preferably from 99:1 to 50:50, especially from 95:5 to 80:20 and most preferably 90:10.
It is preferred that the organic solvent present in the mixture of water and organic solvent is a water-miscible organic solvent or a mixture of such solvents.
Suitable water-miscible organic solvents include C1-5-alkanols, e.g. methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol and isobutanol; amides, e.g. dimethytormamide and dimethylacetamide; ketones and ketone alcohols, e.g. acetone and diacetone alcohol; C2-4-ether, e.g. tetrahydrofuran and dioxane; alkylene glycols or thioglycols containing a C2-C6 alkylene group, e.g. ethylene glycol, propylene glycol, butylene glycol, pentylene glycol and hexylene glycol; poly(alkyleneglycol)s and thioglycol)s, e.g. diethylene glycol, thiodiglycol, polyethylene glycol and polypropylene glycol; polyols, e.g. glycerol and 1,2,6-hexanetriol; and lower akyl glycol and polyglycol ethers, e.g. 2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy) ethanol, 2-(2-butoxyethoxy)ethanol, 3-butoxypropan-1-ol, 2[2-(2-methoxyethoxy)-ethoxy]ethanol, 2-[2-(2-ethoxyethoxy)ethoxy]-ethanol; cyclic esters and cyclic amides, e.g. optionally substituted pyrrolidones; sulpholane; and mixtures containing two or more of the aforementioned water-miscible organic solvents. Preferred water-miscible organic solvents are C1-6-alkyl mono ethers of C2-6-alkylene glycols and C1-6-alkyl mono ethers of poly(C2-6-alkylene glycols).
Suitable water-immiscible organic solvents include aromatic hydrocarbons, e.g. toluene, xylene, naphthalene, tetrahydronaphthalene and methyl naphthalene; chlorinated aromatic hydrocarbons, e.g. chlorobenzene, fluorobenzene, chloronaphthalene and bromonaphthalene; esters, e.g. butyl acetate, ethyl acetate, methyl benzoate, ethyl benzoate, benzyl benzoate, butyl benzoate, phenylethyl acetate, butyl lactate, benzyl lactate, diethyleneglycol dipropionate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di (2-ethylhexyl) phthalate; alcohols having six or more carbon atoms, e.g. hexanol, octanol, benzyl alcohol, phenyl ethanol, phenoxy ethanol, phenoxy propanol and phenoxy butanol; ethers having at least 5 carbon atoms, preferably C5-14 ethers, e.g. anisole and phenetole; nitrocellulose, cellulose ether, cellulose acetate; low odour petroleum distillates; turpentine; white spirits; naphtha; isopropylbiphenyl; terpene; vegetable oil; mineral oil; essential oil; and natural oil; and mixtures of any two or more thereof. Benzyl alcohol is especially preferred.
The ink optionally contains a biocide, for example Proxel GXL (Proxel is a trade mark of Avecia Limited) or Kathon (Kathon is a trade mark of Rohm and Haas), a fungicide, a rheological agent, e.g. a wax (e.g. beeswax), a clay (e.g. bentonite), an IR absorber, for example Projet 900NP (Projet is a trade mark of Avecia Limited), or a fluorescent brightener, for example C.I. Fluorescent Brightener 179 and/or UV absorber, for example hydroxy phenylbenzotriazole. Furthermore the ink optionally contains a surface active agent, wetting agent and/or an emulsifier, for example those described in McCutcheon""s Emulsifiers and Detergents 1996 International Edition or in Surfactants Europa 3rd Edition 1996 each of which is incorporated herein by reference. In a preferred embodiment the ink of the present invention does not contain any pigments.
The ink preferably has a pH from 3 to 11, more preferably from 4 to 10. The pH selected will depend to some extent on the desired cation for colorant and the material used to construct the ink jet printer head. The desired pH may be obtained by the addition of an acid, base or pH buffer. Where a base is used this is preferably the same base as was used to neutralise any anionic dispersing group during the preparation of the water-dissipatable polymer of the invention.
The viscosity of the ink is preferably less than 20 mPa.s (cP), more preferably less than 15 mPa.s (cP), especially less than 10 mPa.s(cP), at 20xc2x0 C.
Preferably the ink has been filtered through a filter having a mean pore size below 10 xcexcm, preferably below 5 xcexcm, more preferably below 2 xcexcm, especially below 0.45 xcexcm. In this way particulate matter is removed which could otherwise block fine nozzles in an ink jet printer.
Preferably the ink contains less than 500 ppm, more preferably less than 250 ppm, especially less than 100 ppm of in total of divalent and trivalent metal ions.
The inks of the present invention have the advantage that they are suitable not only for the use in piezoelectric ink jet printer but also in thermal and continuous ink jet printers. Many other inks based on polymers work poorly or even not at all in thermal ink jet printers.
Inks of the present invention form discrete droplets on the substrate with little tendency for diffusing. Consequently sharp images with excellent print quality and little if any bleed between colours printed side by side can be obtained. Furthermore the inks show good storage stability, wet and light fastness and fastness to both acidic and alkaline highlighter pens.
A third aspect of the invention provides a process for printing an image on a substrate comprising applying thereto an ink according to the second aspect of the present invention by means of an ink jet printer.
The ink jet printer preferably applies the ink to the substrate in the form of droplets which are ejected through a small nozzle onto the substrate. Preferred ink jet printers are piezoelectric ink jet printers and thermal ink jet printers. In thermal ink jet printers, programmed pulses of heat are applied to the ink in a reservoir by means of a resistor adjacent to the nozzle, thereby causing the ink to be ejected in the form of small droplets directed towards the substrate during relative movement between the substrate and the nozzle. In piezoelectric ink jet printers the oscillation of a small crystal causes ejection of the ink from the nozzle.
The substrate is preferably a paper, plastic, or textile material, more preferably a paper, an overhead projector slide or a textile material, especially paper.
Preferred papers are plain, coated or treated papers which may have an acid, alkaline or neutral character. Most preferably the substrate is a coated paper.
According to a fourth feature of the invention there is provided an ink jet printer cartridge, optionally refillable, containing an ink as hereinbefore defined.


In at least some embodiments, an apparatus includes a hydraulic directional control manifold and a plurality of electric piezopumps. The apparatus also includes an electric piezopump controller that operates the plurality of electric piezopumps in varying combinations to provide generation and directional control of hydraulic power to linear hydraulic actuators using localized closed-loop hydraulic fluid.

Deepwater accumulators provide a supply of pressurized working fluid for the control and operation of subsea equipment, such as through hydraulic actuators and motors. Typical subsea equipment may include, but is not limited to, blowout preventers (BOPS) that shut off the well bore to secure an oil or gas well from accidental discharges to the environment, gate valves for the control of flow of oil or gas to the surface or to other subsea locations, or hydraulically actuated connectors and similar devices.
Accumulators are typically divided pressure vessels with a gas section and a hydraulic fluid section that operate on a common principle. The principle is to precharge the gas section with an inert, dry, ideal gas (usually nitrogen or helium), pressurized to a pressure at or slightly below the anticipated minimum pressure required to operate the subsea equipment. Hydraulic fluid will then be added (or "charged") to the accumulator in the separate hydraulic fluid section, increasing the pressure of the pressurized gas and the hydraulic fluid to the maximum operating pressure of the control system. The precharge pressure determines the pressure of the very last trickle of fluid from the fluid side of the accumulator, and the charge pressure determines the pressure of the very first trickle of fluid from the fluid side of the accumulator. The discharged fluid between the first and last trickle will be at some pressure between the charge and precharge pressure, depending on the speed and volume of the discharge and the ambient temperature during the discharge event. The hydraulic fluid introduced into the accumulator is therefore stored at the maximum control system operating pressure until the accumulator is discharged for the purpose of doing hydraulic work.
Accumulators generally come in three styles—the bladder type having a balloon type bladder to separate the gas from the fluid, the piston type having a piston sliding up and down a seal bore to separate the fluid from the gas, and the float type with a float providing a partial separation of the fluid from the gas and for closing a valve when the float approaches the bottom to prevent the escape of the precharging gas. A fourth type of accumulator is pressure compensated for water depth and adds the precharge pressure plus the ambient seawater pressure to the working fluid.
The precharge gas can be said to act as a spring that is compressed when the gas section is at its lowest volume/greatest pressure and released when the gas section is at its greatest volume/lowest pressure. Accumulators are typically precharged on the surface in the absence of hydrostatic pressure and subsequently charged with hydraulic fluid on the seabed under full hydrostatic pressure. The surface precharge pressure is limited by the pressure containment and structural design limits of the accumulator vessel under surface ambient conditions. Yet, as accumulators are used in deeper water, the efficiency of conventional accumulators decreases as application of hydrostatic pressure causes the gas to compress, leaving a progressively smaller volume of gas to charge the hydraulic fluid. The gas section must consequently be designed such that the gas still provides enough power to operate the subsea equipment under hydrostatic pressure even as the hydraulic fluid approaches discharge and the gas section is at its greatest volume/lowest pressure.
The use of accumulators at extreme water depths requires large aggregate accumulator volumes that increase the size and weight of the overall subsea equipment assemblies. Yet, offshore rigs continue moving further and further offshore to drill in deeper and deeper water. Because of the ever increasing envelop of operation, traditional accumulators are becoming unmanageable with regards to quantity and location inside existing stack frames. In some instances, it has even been suggested that in order to accommodate the increasing demands of the conventional accumulator system, a separate subsea skid may have to be run in conjunction with the subsea BOP stack in order to provide the required volume necessary at the limits of the water depth capability of the subsea BOP stack. With rig operators increasingly putting a premium on minimizing size and weight of the drilling equipment to reduce drilling costs, the size and weight of all drilling equipment must be optimized.
The bulk transmission of hydraulic power to accumulators are affected by the ambient pressure at the sea floor and requires their designs to account for: 1) hydrostatic effects; 2) consequential design pressure ratings for subsea hydraulic accumulator pre-charge; and 3) volume requirements to meet performance requirements for the external hydraulic actuator. Also, transmission of hydraulic power through pipes is subject to line pressure losses due to line geometry, length, and fluid conditions. Further, different external hydraulic actuators require differing regulated pressure, requiring the use of a plurality of regulators for each type of hydraulic actuator.
Prior approaches to addressing operation of subsea linear actuators have involved replacement of the linear hydraulic actuator with a rotary electric motor, transmission, clutch, and lock. However, electromechanical losses associated with the electric rotary motor and mechanical losses associated with the transmission, clutch, and lock have led to power inefficiencies and significant complexity increases that reduce reliability, availability, and maintainability of all electric solutions over all hydraulic solutions.

Methods and systems for subsea electric piezopumps


This invention is a method of power amplifier digital pre-distortion which measures a current power level of the power amplifier, stores in a look up table entries consisting of a power level and a corresponding set of digital pre-distortion coefficients, selects a set of digital pre-distortion coefficients corresponding to the measured power level. If the measured current power level is near a power level index, the digital pre-distortion coefficients correspond to the power level index. If the measured current power level is greater than the maximum power level entry, the digital pre-distortion coefficients is of the maximum power level entry. If the measured current power level is less than the minimum power level entry, the digital pre-distortion is of the minimum power level entry. If the measured current power level is not near a power level index, the digital pre-distortion coefficients are an interpolation.

Power amplifiers (PA) used in radio transmitter for most telecommunication systems have only a limited linear operation region. The nonlinearity introduced by the PA can cause nonlinear distortion of the output signal and interference on adjacent radio channel frequencies. Digital Pre-distortion may compensate for this non-ideal behavior of the PA by pre-distorting the data applying the inverse nonlinearity of PA to the PA input. This thus produces a linear overall system response. Generally PAs exhibit very different nonlinear behavior for signals with different power levels. Applications with multi-carrier communications can have huge power variations over a short time interval. In the LTE signal the carrier power may vary as much as 20 dB over 1 to 2 ms adjacent time slots. It is quite difficult for DPD to re-adapt for a new solution within such short time.

Power-indexed look-up table design of digital pre-distortion for power amplifiers with dynamic nonlinearities


To improve data throughput and data transfer rate, a contiguous block of host memory can be allocated for data transfers between the host system and an integrated circuit device such as a peripheral component. By using a contiguous block of memory that acts as a circular buffer, the memory address field of memory descriptors can be eliminated because the host system only need to inform the data movement engine of the length of each data transfer. The data movement engine can maintain pointers to keep track of the memory address in the host memory to read from and write to. After each data transfer, the relevant pointer can be incremented by a value corresponding to the length indicated in the memory descriptor for the transfer. As such, it is not necessary for the host system to provide the data movement engine with the memory address of each transfer.

A host computing system can be equipped with different types of peripheral components to enhance the functionality of the host system. The peripheral components can be in the form of add-in cards, and may implement various functionalities such as networking, encryption, graphics processing, etc. The peripheral components can be implemented using integrated circuit devices such as application-specific integrated circuits, programmable logic devices, and the like. In a cloud-computing environment, a peripheral component implemented using a programmable logic device such as a field programmable gate array (FPGA) can allow a client to implement custom logic to perform specialized tasks on the host system.

DMA engine that generates an address-less memory descriptor that does not include a memory address for communicating with integrated circuit device


A power supply apparatus for coupling electricity between a power source and a device. The apparatus including a body having at least one aperture and at least one electrical contact configured to mate with the power source; at least one light source arranged within the body; and at least one light transmitting cover. The cover configured to cover the at least one aperture. The cover having indicia thereon. The at least one light source arranged to radiate through the at least one aperture and backlight the indicia. Manufacture of the power supply apparatus may be performed in large volumes and desired indicia later added and or changed via the cover, increasing manufacturing efficiency and flexibility.

1. Field of the Invention
The invention generally relates to a power supply apparatus. Specifically, the invention relates to a power supply apparatus with illuminated indicia capability useful, for example, for displaying brand and or advertising information.
2. Description of Related Art
A power supply apparatus may be used to couple an electrical device to an electrical power source. The cigarette lighter/12 Volt power socket found in most consumer vehicles has become a standard electrical power source usable with power supply apparatus for many mobile devices, for example, cellular telephones and or portable computers. A power supply apparatus in the form of a cigarette lighter adapter (CLA) may be configured to mate with the cigarette lighter/12 Volt power socket to supply electrical current to a desired device. The electrical current may be used, for example, to operate the device and or charge a battery therein.
The cigarette lighter/12 Volt power socket is typically located for easy access by the vehicle operator, i.e. it is located in plain view of the operator and or other vehicle occupants. CLAs may include a light emitting diode (LED), incandescent lamp or other low power consumption light source that illuminates upon insertion into the cigarette lighter/12 Volt power socket to provide visual feedback indicating that an electrical connection has been made and or that electrical power is present.
Manufacturers/sellers of electrical devices, services and their accessories, for example cellular telephone service providers, compete within their market segments, often offering identical hardware. In an attempt to increase sales and profitability by differentiating themselves from their competition, manufacturers/sellers seek and are willing to pay a premium for opportunities to build brand recognition and consumer goodwill.
A power supply apparatus manufacturer seeking to increase manufacturing efficiency may offer the same power supply apparatus configuration to multiple electrical device manufacturers/sellers on an original equipment manufacturer (OEM) basis. Extra costs related to OEM sales may include, for example, extra design and manufacturing steps required for adding individual branding for each different customer. Also, there is a chance that an OEM sale will be canceled prior to delivery, leaving the manufacturer with an inventory of power supply apparatus that may not be profitably resold due to the presence of the canceling customer""s irremovable branding upon the power supply apparatus.
Therefore, it is an object of the invention to provide a method and apparatus that overcomes deficiencies in the prior art.

Illuminated indicia power supply apparatus and method of manufacture


Embodiments of the invention provide a method of and apparatus for graphically marking a series of portable objects, such as a card, each portable object being graphically marked on a respective zone by a respective marking device, wherein the marking devices are configured to perform the same marking operation simultaneously on a plurality of portable objects.

In its most general form the invention provides a method of and apparatus for graphically marking a series of portable objects, each portable object being graphically marked on a respective zone by a respective marking device, wherein the marking devices are configured to perform the same marking operation simultaneously on a plurality of portable objects.
Accordingly, a first aspect of the invention provides a method of graphically marking a series of portable objects, each portable object being graphically marked by a plurality of graphical marking procedures, the method comprising: receiving a first portable object at a first graphical marking station for graphical marking of a first zone of the first portable object by a first graphical marking means of the first graphical marking station; receiving a second portable object at a second graphical marking station for graphical marking of a first zone of the second portable object by a second graphical marking means of the second graphical marking station; graphically marking a first marking layout on the first zone of the first portable object by means of the first graphical marking means and simultaneously graphically marking the same first marking layout on the first zone of the second portable object by means of the second graphical marking means; transferring the first portable object to the second graphical marking station for graphical marking of a second zone of the first portable object by the second graphical marking means, wherein the second zone is different to the first zone; receiving a further portable object at the first graphical marking station for graphical marking of a second zone of the further portable object, by the first graphical marking means of the first graphical marking station; graphically marking a second marking layout on the second zone of the first portable object by means of the second graphical marking means, wherein the second marking layout is different to the first marking layout, and simultaneously graphically marking the same second marking layout on the second zone of the further portable object by means of the first graphical marking means. The further portable object may be subsequently transferred to the second graphical marking station for graphical marking of a first zone of the further portable object, by the second graphical marking means with the first graphical marking layout if so required.
A second aspect of the invention provides a graphical marking apparatus for graphically marking a series of portable objects by a plurality of graphical marking procedures carried out sequentially on each of the plurality of portable objects, each portable object having a first zone to be marked with a first graphical marking layout and a second different zone to be marked with a second different graphical marking layout, the apparatus comprising: a first marking station comprising first graphical marking means operable to graphically mark the first graphical marking layout or, alternatively, the second graphical marking layout on a portable object of the series of portable objects; and a marking location for receiving the portable object to be marked; a second marking station comprising second graphical marking means operable to graphically mark the first graphical marking layout or, alternatively the second graphical marking layout on a portable object; and a marking location for receiving the portable object to be marked; a transfer device for transferring a portable object from the first marking station to the second marking station; wherein the first marking station is operable to graphically mark the first graphical marking layout on the first zone of a portable object, of the series of portable objects, when said portable object is located at the marking location; and to graphically mark the second graphical marking layout on the second zone of a further portable object of the series of portable objects when said further portable object is located at the marking location; wherein the second marking station is operable to graphically mark the second graphical marking layout on the second zone of the said portable object of the series of portable objects when said portable object is located at the marking location; and to graphically mark the first graphical marking layout on the first zone of the said further portable object of the series of portable objects when the said further portable object is located at the marking location; and wherein the first marking station and the second marking station are configured to simultaneously graphically mark the first graphical marking layout on a respective portable object, and to simultaneously graphically mark the second graphical marking layout on a respective portable object.
It will be appreciated that the first zone of the second object may or may not correspond to the first zone of the first object. The objects may receive the same marking layout on the same zone or on different zones.
In embodiments of the invention:                the first zone of the corresponding portable object corresponds to at least a portion of a first surface of the said portable object and the second zone corresponds to at least a portion of a second opposing surface of the said portable object, the method further comprising or the apparatus further comprising means for flipping the said portable object after a first surface has been graphically marked by the first graphical marking means so that the second surface can be graphically marked by the second graphical marking means.        the first graphical marking station and the second graphical marking station may each be provided with a first marking location and a second distinct marking location;        the method may further comprise or the apparatus may further comprise means for receiving a portable object from the series of portable objects at the first marking location; directing the first graphical marking means to the first marking location; graphically marking the said portable object at the first marking location while simultaneously receiving another portable object, from the series of portable objects, at the second marking location; redirecting the first graphical marking means to the second marking location; and graphically marking the other portable object at the second marking location while simultaneously replacing the said portable object at the first marking location with a further portable object from the series of portable objects.        the same graphical marking layout may be performed at the first and subsequently at the second marking location        the first marking station may graphically mark at least two sequential portable objects with the first marking layout on the first zone of the respective portable object before graphically marking at least two further sequential portable objects with the second marking layout on the second zone of the respective portable objects.        the first marking station may graphically mark four sequential portable objects with the first marking layout on the first zone of the respective portable object before graphically marking four further sequential portable objects with the second marking layout on the second zone of the respective portable objects.        the graphical marking means may include a laser and the directing means comprises optical means for enabling the beam from the laser to be deflected alternately on to one or other of the marking locations.        each marking location may be provided with a corresponding transfer path in the marking station for transferring a portable object to the corresponding marking location.
At least parts of the methods according to the invention may be computer implemented. The methods may be implemented in software on a programmable apparatus. They may also be implemented solely in hardware or in software, or in a combination thereof.
Since at least parts of the present invention can be implemented in software, the present invention can be embodied as computer readable code for provision to a programmable apparatus on any suitable carrier medium. A tangible carrier medium may comprise a storage medium such as a floppy disk, a CD-ROM, a hard disk drive, a magnetic tape device or a solid state memory device and the like. A transient carrier medium may include a signal such as an electrical signal, an electronic signal, an optical signal, an acoustic signal, a magnetic signal or an electromagnetic signal, e.g. a microwave or RF signal.

Method of and apparatus for personalising a series of portable objects


The present invention relates to an expansion joint to bridge an expansion gap between two parts of concrete slabs used in floor construction, especially in the manufacture of concrete floors such as for example in industrial floors. Such expansion joints are evidently required to take up the inevitable shrinkage process of the concrete and to assure that the floor elements can expand or contract such as for example occur by temperature fluctuations and resulting in a horizontal displacement of the floor panels vis-à-vis one another.

In addition, and given the fact that such floors are often subjected to high loads, further load transfer elements are typically included in the aforementioned joint profiles to assure that the vertical load on one floor panel is transmitted to the adjacent floor panel in an optimal way and thereby preventing a vertical tilting of the floor panels with respect to each other. However, when driving over such an expansion joint with heavily loaded vehicles such as forklifts, which often have particularly hard Vulkollan wheels, the presence of such load transfer elements cannot prevent damage of the upper circumferential edges of the slabs or to the wheels, due to the undesirable shock of the vehicle when passing the groove-like gap between the floor elements. This is especially due to the fact that the joint profile making up the edges of the floor elements is made of steel and therefore much harder than the commonly soft outer circumference surface of the wheels.
In an effort to address the drawback of the groove-like gap in the existing joint profiles, alternatives have been presented wherein the edges of the floor members by means of coggings interlock with one another. See for example AT113488, JP2-296903, DE3533077 or WO2007144008. However, in as far each of said arrangements ensures that the wheels when leaving one edge are already supported on the boundary of the other; the mere presence of such cogging interlocks is insufficient to prevent damage at the upper circumferential edges of the floor elements. Vertical tilting of the floor members may still result in differences in height between the plates which gives rise to edges, further shocks and eventual damages to the floor. Consequently, also in these interlocking joint profiles load transfer elements will be required to assure that the vertical load on one floor panel is transmitted to the adjacent floor panel in an optimal way and thereby preventing a vertical tilting of the floor panels.
Such load transfer elements come in different shapes and embodiments, such as for example wedge-shaped dowels (DE 102007020816); horizontal grooves and protrusions cooperating with one another (BE1015453, BE1016147); plate dowels (U.S. Pat. No. 5,674,028, EP1584746, US2008222984) or bar dowels (EP0410079, U.S. Pat. No. 6,502,359, WO03069067, EP0609783). Irrespective of their embodiment, said load transfer elements needs to be incorporated in the floor deck adding not only to a minimum thickness for the floor, but also to additional material to be used and to complexity in construction.
In addition, metal interlocking end plates such as shown in AT113488 and JP-2-29603, still result in an abrupt change of expansion coefficient at the boundary of the floor slabs. As a consequence, these end plates tend to loosen over time with floor damage at the boundary between the concrete floor slabs at the metal end plates.


An afterburner assembly is disclosed in which the flameholder ring is for by plurality of flameholder ring segments, each segment being integrally formed with a generally radially extending arm. The flameholder ring segments extend beyond each opposite sides of the arm. The arm and flameholder ring segments are attached to the casing of the afterburner by a support element which is pivotally attached to the arm and fixedly attached to the afterburner casing. The distal end of the arm slidably contacts the casing defining the opposite side of the afterburner duct to enable the arm to slide relative to the casing to allow for differential thermal expansion of the respective elements. When each of the arm/flameholder ring segments are attached to the afterburner casing, the flameholder ring segments form a generally annular flameholder ring. The ring has a generally "U"-shaped cross-sectional configuration with the legs of the "U"-shape extending generally parallel to a central axis and opening in a downstream direction according to the gas flow flowing through the afterburner duct.

The present invention relates to an afterburner assembly for a gas turbine engine, such as an aircraft turbojet, wherein the afterburner flameholders exhibit a simplified construction.
Afterburners for turbojet engines are well-known in the art and typically comprise one or more annular flameholder rings supported within the afterburner duct. It is also known to make the flameholder rings from composite materials. However, the prior art devices have been affixed to the casings defining the afterburner duct by separate, generally radially extending arms which renders the designs comparatively heavy and bulky. Furthermore, the bulky structure introduces disturbances and pressure drops within the gases flowing through the afterburner thereby reducing the overall efficiency of the gas turbine engine.

Afterburner assembly for a gas turbine engine

Societe Nationale d'Etude et de Construction de Moteurs d'Aviation


To provide an optical head wherein no collimate lens nor object lens is used and photo-detection can be made with more than one reflection beams, the optical head has an optical system (101) comprising a collimate hologram (104) working as a collimate lens, an object hologram (105) working as an object lens, a two-portion Leith-type ring-band-plate hologram (106) for converting plane-wave light from the object hologram (105) into spherical-wave light converging on a pair of photo-detectors (107 and 108). The two-portion Leith-type ring-band-plate hologram (106) has two symmetrical portions each having a carrier component symmetrical to each other and each diffracting the plane-wave light into a part of the spherical light converging on a position which is shifted from a center line of respective one of the two symmetrical portions by a carrier angle of the respective one.

The present invention relates to an optical disk device, and particularly to an optical head of the optical disk device making use of holograms and an optical information reading method applied in the optical head.
Along with progress of high-density and large-capacity technology of memory devices, narrower tracks and finer pits are pursued in optical disks. For enabling the finer pit size, technical improvement of the optical head performance such as converging performance for irradiating a micro-spot, fine focusing control, accurate tracking servo or high sensitivity to the pit signal is indispensable. For realizing the high performance and the miniaturization as well of the optical head, application of the hologram to the optical head has been earnestly studied.
FIG. 6 is a perspective view schematically illustrating an optical head making use of a hologram which is described in "Optical Disk System for Multimedia", by Imanaka et al., National Technical Report, Vol. 40, No. 6, pp. 771-778, December 1994, (hereinafter called the first prior art). In the first prior art of FIG. 6, a laser light which is reflected by a recording medium 602 and made parallel through an object lens 605, is divided into two beams by a two-portion grid-type hologram 606 and converged by a collimate lens 604. The converged two beams of +1.sup.st order waves are detected by a pair of photo-detectors 607 to be processed by a signal processor. This is a typical example of a CFT (Correct Far-field Tracking) hologram head.
FIG. 7 is a side view illustrating another prior art example of the hologram head, which is disclosed in a Japanese patent application laid open as a Provisional Publication No. 248144/'87 (hereinafter called the second prior art). For miniaturizing and lightening optical pickup-mechanism, the collimate lens and the object lens are replaced with phase-type holograms, whereby an incident laser light is diffracted and converged on a recording medium, in the second prior art.
Referring to FIG. 7, a laser diode 703 generates a laser light S-polarized having an oscillation plane perpendicular to the drawing sheet, which penetrates a first phase-type hologram 706b being incident with a non-Bragg angle, and diffracted by a second phase-type hologram 706a having interference fringes perpendicular to the sheet to be converged on an optical disk 702. Between the second phase type hologram 706a and the optical disk 702, there is provided a quarter-wavelength plate 705, which makes circularly-polarized the laser light to be converged on the optical disk 702, and makes P-polarized the laser light reflected by the optical disk 702 to have an oscillation plane parallel to the sheet, so that the reflected laser light penetrates the second phase-type hologram 706a and is diffracted by the first phase-type hologram 706b being incident with a Bragg angle to be converged on a photo-detector 707.
In order to miniaturizing the optical head, the size of its optical system, that is, the light-path length between the light source or the photo-detector and the recording medium should be reduced. However, the reduction of the light-path length is limited in the first prior art of FIG. 6, because the collimate lens and the object lens inserting the hologram between them should be arranged at a certain distance to the light source and the photo-detector adjoining with each other.
For miniaturizing and thinning the optical system, the collimate lens and the object lens are replaced with holograms in the second prior art of FIG. 7. However, the second prior art requires high precision phase-type holograms minutely arranged, considering complex polarization components of the holograms whereon the laser light is incident with the Bragg angle. Further, the complexity of the diffraction efficiency may cause output instability of the optical head.
Still further, the servomechanism of the second prior art depends on photo-detection of a single reflection beam. Therefore, the focusing and tracking accuracy should be degraded compared to ordinary servomechanism wherein the reflection beam is split into two beams for improving detection accuracy.

Optical head and an optical information reading method applied therein