In a blower for compulsorily circulating a laser gas for a gas laser apparatus, a shaft (2) of an impeller (1) is fitted with an intermediate member (66) that rotates together therewith, and rings (641, 642) are fitted individually in annular grooves (651, 652) formed on the intermediate member (66). On the other hand, a bearing holder (60) for holding a bearing (5) that supports the shaft (2) is provided with a ring holder (63) having an inner wall kept normally in contact with the respective outer peripheral surfaces of the rings (641, 642). As a result, narrow axial gaps between the rings (641, 642) and the annular grooves (651, 652) prevent gaseous impurities from getting into a gas laser circulation path through a bearing (5).

A carbon dioxide gas laser oscillation apparatus of a high-speed axial flow type, a typical gas laser oscillation apparatus, can produce high output and high-quality laser beams with a compact design, so that it has been widely utilized for laser work, such as cutting of metallic and nonmetallic materials and welding of metallic materials and the like. In particular, this apparatus is rapidly developing as a CNC laser work machine that is coupled with a CNC (numerical control device) and used in the field of high-speed, high-accuracy cutting work for complicated shapes.
In the carbon dioxide gas laser oscillation apparatus, about 20% of injected electrical energy is converted into laser beams, and the remainder is consumed in heating of a laser gas. On the other hand, the laser oscillation gain inevitably lowers as the temperature of the laser gas increases. In order to enhance the oscillation efficiency, therefore, it is necessary to cool the laser gas compulsorily, thereby making the laser gas temperature as low as possible. Accordingly, in the carbon dioxide gas laser apparatus of the high-speed axial flow type, a gas laser blower is used to circulate the laser gas compulsorily in the apparatus and feed it into the cooler.
FIG. 6 shows a vertical gas laser blower of an oil circulation type, as an example of this gas laser blower. In a gas laser blower 100, a shaft 2 that fixes an impeller 1 is arranged vertically. When the impeller 1 rotates, a laser gas is sucked in from a cooler (not shown) on the upstream side (or above the shaft) toward the impeller 1, passing in the direction of the shaft 2 (direction of arrow 9) along an upstream-side circulation path U. Then, the laser gas is caused to be discharged in a direction (direction of arrow 10) perpendicular to the direction of axis of the shaft by the impeller 1, and flows into a cooler (not shown) on the downstream side through a downstream-side circulation path D.
After the impeller 1 is fitted on the upper end portion of the shaft 2, it is fixedly coupled to the shaft 2 by fastening the upper end of the shaft 2 by means of a nut 7. The impeller 1 fixed to the shaft 2 is covered by a circulation-path-side casing 8 that defines the laser gas circulation paths U and D.
A rotor 3 is fixed to the axial central portion of the shaft 2 by shrink fitting. The rotor 3 is covered by a motor-side casing 12. A stator 4 is fixed to that part of the motor-side casing 12 which faces the rotor 3. The rotor 3 and the stator 4 constitutes a high-frequency motor 30. As a result, the impeller 1 is rotated at a high speed of tens of thousands of rpm.
The shaft 2 is supported on the apparatus body by means of a pair of bearings 5 and 6. The bearing 5 on the upper side is provided in a communication hole 121a that is formed in a partition wall 121 between the motor-side casing 12 and the circulation-path-side casing 8. The bearing 6 on the lower side is mounted on a shaft supporting portion 20 which will be mentioned later. Normally, angular ball bearings, which can stand high-speed rotation, are used as these bearings 5 and 6, individually.
An oil passage 13 is provided in the shaft 2, extending in the axial direction thereof. A plurality of oil outlets 131 with a small bore that connect the oil passage 13 and the outside are formed in the vicinity of such part of the shaft 2 as is supported by the bearing 5.
On the lower end side of the shaft 2, an oil suction head 17, having its outer periphery tapered toward the distal end (downward), is provided integrally with the shaft 2. This oil suction head 17 is provided with an oil passage 13 that communicates with the oil passage 13 in the shaft 2, and an oil inlet 130 of the oil passage 13 is formed at the lower end of the shaft 2.
Around the lower end portion of the shaft 2 or right under the motor 30, an oil reservoir 18 is fixed to the apparatus body. Around the oil suction head 17, moreover, the cylindrical shaft supporting portion 20 is fixed integrally to the oil reservoir 18. A bottom opening (not shown) of this oil reservoir 18 is connected to one end of an oil passage 180, and the other end of the oil passage 180 communicates with an aperture 201 in the center of the bottom portion of the shaft supporting portion 20. Thus, oil in the oil reservoir 18 flows into the cylindrical shaft supporting portion 20 via the oil passage 180 and the aperture 201. The oil injected into the shaft supporting portion 20 further gets into the oil passage 13 through the oil inlet 130 at the lower end of the oil suction head 17. As a result, oil in the oil reservoir 18, oil in the shaft supporting portion 20, and oil in the oil passage 13 are all kept on the same level when the impeller 1 is stationary.
A cylindrical bearing sleeve 21 is fitted in the cylindrical shaft supporting portion 20 for axial sliding motion. This bearing sleeve 21 includes a projecting portion 210 that projects for a given length toward the axis. The upper end of the projecting portion 210 is in contact with the outer ring of the bearing 6, and the lower end in contact with the free end of a spring 16. The proximal end of the spring 16 is fixed to the bottom of the shaft supporting portion 20. Thus, the elasticity of the spring 16 first acts as a force to push up the bearing sleeve 21, and in consequence, this force is transmitted to the bearing 6, shaft 2, and bearing 5 in succession. As a result, the bearings 5 and 6 that support the shaft 2 are kept under a pre-load applied by the spring 16.
An oil return passage 15 is provided extending along the axial direction of the shaft 2 in such part of the motor-side casing 12 as surrounds the stator 4 that constitutes the motor 30. Further, a cooling water passage 19 is provided extending along the oil return passage 15 in such part of the motor-side casing 12 as surrounds the region for the oil return passage 15.
The oil in the oil passage 13 in the oil suction head 17 is pressed against the inner wall surface of the oil passage 13 by means of a centrifugal force that is produced as the shaft 2 fitted with the impeller 1 rotates. As this is done, the oil is subjected to a component force in the direction to push up the oil along the inner wall surface. As a result, the oil is sucked up rapidly, and is discharged from the oil outlets 131 through the oil passage 13 in the shaft 2. Some of the discharged oil is supplied to the bearing 5 and used to lubricate the bearing 5. The discharged oil returns to the oil reservoir 18 through the oil return passage 15. As it passes through the oil return passage 15, the oil is cooled by cooling water in the cooling water passage 19. The oil returned to the oil reservoir 18 passes through the oil passage 180, communicates with the bottom opening of the oil reservoir 18, and flows into the cylindrical shaft supporting portion 20. Then, the oil introduced into the shaft supporting portion 20 further gets into the oil passage 13 through the oil inlet 130 at the lower end of the oil suction head 17. Thus, the oil continually circulates while the shaft 2 is rotating.
In the motor-side casing 12, a lubricant supplied to the bearing 6 evaporates, and impurity gas is generated from the drive motor 30. The resulting vapor and gas may possibly get into the circulation-path-side casing 8 through the bearing 5 and the communication hole 121a formed in the partition wall 121 to which the bearing 5 is attached, and be mixed in the laser gas flowing through the circulation paths.
More specifically, the bearings 5 and 6 support the shaft 2 which is rotating at high speed, so that the lubricant to be supplied to these bearings 5 and 6 has to be particularly highly lubricative. Therefore, those lubricants with extremely low vapor pressures which are used in conventional high-vacuum apparatuses cannot be used for the purpose on account of their low lubricating properties. As a result, the lubricant selected to be supplied to the bearings 5 and 6 is easily reduced to vapor despite their low vapor pressures.
Since the shaft 2 that rotates at high speed penetrates the partition wall 121 so as to be situated both in the motor-side casing 12 and in the circulation-path-side casing 8, on the other hand, the motor-side casing 12 and the circulation-path-side casing 8 cannot be isolated entirely from each other. Thus, the vapor from the highly lubricative lubricant itself, supplied to the bearings 5 and 6, and the gas generated from the motor 30 flow into the circulation-path-side casing 8 through the communication hole 121a in the partition wall 121, and gets into the laser gas circulation paths. In some extreme cases, the lubricant itself used to get into the circulation-path-side casing 8 through a narrow gap in the partition wall 121.
As a result, the laser gas, being contaminated with the aforesaid gas and vapor, entails reduction in the laser output. Further, the substances introduced from the motor-side casing 12 into the laser gas circulation paths, being deposited on an output coupler mirror, total reflector, and other optical components that constitute an optical resonator, cause reduction in the laser output, breakage of the optical components, etc. These problems are not peculiar to the gas laser blower of an oil lubrication type, but are also aroused in the cases of grease lubrication and other lubrication systems.
Therefore, to cope with these problems, the laser gas is extracted from the laser gas circulation paths and the quantity of replenishment is increased. However these conventional countermeasures would entail an increase in the running cost of the laser oscillation apparatus.
Further, it is devised to minimize the size of the communication hole 121a for bearing attachment provided in the partition wall 121 that divides the motor-side casing 12 and the circulation-path-side casing 8. But this countermeasure would cause problems such that the machining accuracy is limited and the costs are increased for nothing, so that its effect is unsatisfactory.
In one case, moreover, the shaft 2 is provided with a disk-shaped oil thrower in order to prevent the lubricant from getting directly into the circulation-path-side casing. Also in this case, however, the through hole cannot be narrowed due to the limited machining accuracy, and there is hardly any effect on the interception of the vapor from the lubricant and the gas generated from the motor 30.
In another case, furthermore, sealing means, such as a contact-type mechanical seal, is used for sealing between the motor-side casing 12 and the circulation-path-side casing 8. In this case, however, the reliability is very poor and the required life performance cannot be enjoyed, due to wear of sliding surfaces and frictional heat therefrom, so that this countermeasure is not practicable.


The present invention concerns very fast scintillator materials capable of resolving the position of an annihilation event within a portion of a human body cross-section. In one embodiment, the scintillator material comprises LaBr3 doped with cerium. Particular attention is drawn to LaBr3 doped with a quantity of Ce that is chosen for improving the timing properties, in particular the rise time and resultant timing resolution of the scintillator, and locational capabilities of the scintillator.

The present invention relates generally to scintillators. More specifically, the present invention provides lanthanum bromide (LaBr3) scintillators for use with medical imaging scanner systems, such as time-of-flight PET scanner systems.
One form of medical imaging is called positron emission tomography and is better known by its acronym PET. In PET (or PET scan), the patient is injected with or otherwise administered a molecule labeled with a positron-emitting radioactive element. In some applications the radiotracer is distributed through the body, and concentrated in (or excluded from) target tissues of interest. The radioactive material decays by emission of a positron, or antiparticle of the negatively-charged electron. The positron is slowed down within a short distance from the emission point and forms a short-lived "atom" consisting of the positron and an electron from a nearby atom. The "atom," referred to as positronium, decays by the annihilation of its constituents. This annihilation produces two essentially back to back 511 keV gamma rays which are emitted in substantially opposite directions. When both of the gamma rays are detected by detectors surrounding the body, it can be assumed with high probability that the emission point was somewhere along a line joining the two detectors. Without additional information, the probability that the radiotracer was located on any one point in the body that the detection line intersects is equal for all points in the line, and hence, for all points in the body being scanned.
A variety of algorithms have been developed that make it possible to form an image from a collection of such lines. The quality of the image improves, in general, as the number of lines increases. Similarly, as the signal-to-noise of the image depends on the square root of the number of lines, each line representing one annihilation event, more lines offer an improved signal to noise ratio. Nevertheless, a common aspect of all image formation or reconstruction algorithms is that the noise increases in the process of deciding where along the detected line the annihilation event is likely to have occurred. In one aspect, this effect can be thought of in terms of energy and work: The detected lines represent the energy in the image and a large part of that energy is used up as work in localizing the annihilation along the particular line, instead of contributing to image quality. If the body cross-section is 30 cm and the desired localization accuracy of an annihilation event is 5 mm, localization requires reducing the uncertainty of its location by a factor of 60.
The annihilation gamma-rays travel at a speed of about 30 cm/nanosecond (1 foot/ns). The timing accuracy of detectors currently used commercially in PET cameras is a few nanoseconds (ns). Timing resolution is typically applied to two aspects of PET: One use is to reduce accidentals (the overlapped detection of two unrelated gamma-rays). The other use is in timing signals for localization purposes. While any improvement in time resolution aids in accidentals reduction, until the time resolution drops substantially below about 1 ns, greater time resolution will not help in localization of an annihilation event within a target of about 30 cm—the more common presentation in human-PET scanning. That is, if a body cross-section is about 30 cm, that very fact localizes the event without any recourse to time resolution. With that limitation, an improvement in localization from 4 nanosecondss (4 feet) to 1 nanosecond (1 foot) offers no improvement to image quality. On the other hand, a time signal improvement from 1 nanosecond to 500 picoseconds (0.5 nanoseconds) reduces the uncertainty of event location by a factor of 2. To appreciate the value of this particular improvement, it is to be noted that the factor of 2 increase in time resolution accuracy results in a corresponding increase in signal-to-noise ratio. This results in the equivalent of a factor of 4 increase in detected annihilation events. Placed in a different context, under the same circumstances, an image (actually a data set) that may take 15 minutes to obtain with a 1 nanoseconds time resolution, is obtained in under about 4 minutes when the time resolution is 500 picoseconds.
FIG. 1 illustrates the principle on which the location along the detected line is used to improve image formation.
It is generally recognized that a fast timing scintillator in PET cameras will enable time-of-flight PET when the timing accuracy is below 1 nanosecond. Hitherto no true time-of-flight PET device has been enabled. Barium fluoride (BaF2), lutetium orthosilicate (LSO) and bismuth germanate (BGO) have been suggested as potentially useful scintillation materials, but none of these materials has the 500 picosecond (ps) or less time resolution needed to achieve a successful device. BaF2 actually provides a ˜250 ps (FWHM) timing resolution, but it has a low emission intensity for the fast component and emits in blue region of the spectrum where special photomultiplier tubes (PMTs) with quartz windows are required for readout. It is noted that a number of plastic scintillators have a time resolution below 500 picoseconds, but due to inadequate stopping power, (attenuation length at 500 keV is typically greater than 10 cm), these scintillators are not suitable for medical uses.
The present invention provides very fast scintillator materials capable of resolving the positron of an annihilation event within a portion of a human body cross-section (less than 400 picoseconds), specifically, the very fast scintillator material comprises LaBr3 doped with various concentrations of cerium. Particular attention is drawn to the unexpected discovery that the quantity of Ce used to dope LaBr3 improves the timing properties (rise time and timing resolution), stopping power and locational capabilities of the scintillator to provide a scintillator capable of use for actual time-of-flight PET.
Attention is drawn to several references in the field, the teachings of which are incorporated herein by reference (as are all references cited herein):
U.S. Pat. No. 6,362,479, "Scintillation detector array for encoding the energy, position, and time coordinates of gamma ray interactions," discloses a scintillator-encoding scheme that depends on the differential decay time of various scintillators. The use of LSO-LSO crystals with a time resolution of 1.6 nanoseconds is also discussed. A time resolution of 1.6 nanoseconds is equivalent to an approximately 50 cm uncertainty, which is as large as the cross-sectional dimension of the human body, and not useful in the present context.
U.S. Pat. No. 5,453,623, "Positron emission tomography camera with quadrant-sharing photomultipliers and cross-coupled scintillating crystals." Discloses arrangement of hardware elements in PET camera and use of scintillators. Only specific scintillator disclosed is BGO.
Moses et al., "Prospects for Time-of-Flight PET using LSO Scintillator," IEEE Trans. Nucl. Sci. 46:474–478 (1999).
U.S. Pat. No. 5,319,203 and U.S. Pat. No. 5,134,293, both entitled "Scintillator material." Discloses Cerium fluoride and thallium doped Cerium fluoride as "improved" scintillator material.
U.S. Pat. No. 5,039,858, "Divalent fluoride doped cerium fluoride scintillator." Discloses additional doped cerium fluoride scintillators.
U.S. Pat. No. 4,510,394, "Material for scintillators." Discloses barium fluoride as scintillator material.
van Loef et al., "High energy resolution scintillator: Ce3+ activated LaBr3", Appl. Phys. Lett. 79:1573–1575 (2001).
van Loef et al., "Scintillation properties of LaBr3:Ce3+ crystals: fast, efficient and high-energy-resolution scintillators", Nucl. Instr. Meth. Physics Res. A 486:254–258 (2002). Discloses certain characteristics of cerium doped LaBr3 compositrons including, light yield, and scintillation decay curve. The rise time and time resolution of the compositrons are not disclosed or suggested.
WO 01/60945, "Scintillator crystals, method for making same, use thereof", Discloses inorganic scintillator material of the general compositron M1-xCexBr3, where M is selected from lanthanides or lanthanide mixtures of the group consisting of La, Gd, and Y. X is the molar rate of substitution of M with cerium, x being present in an amount of not less than 0.01 mol % and strictly less than 100 mol %. The rise time and time resolution of the various compositrons are not disclosed or suggested.


A sheet feeder, or a printer incorporating the sheet feeder, has separation pads for separating a sheet to be fed by sheet feed rollers from the next sheet and a roller spring which produce urging force smaller than that produced by a spring of the separation pad. Idle rollers are brought into contact with the separation pads by means of the roller spring, thereby preventing the lowering of the next sheet. A sheet reset lever is pivoted so as to return the next sheet to a hopper. As a result, the sheet sheets stacked on the hopper in an inclined state is fed one by one through use of a separation pad method without increasing force for driving rollers and a back tension.

1. Field of the Invention
The present invention relates to a sheet feeder primarily suitable for use with a printer which feeds stacked sheet (plain sheet, coated sheet, sheet used for an OHP (Over-head Projector), glossy sheet, separated sheets such as glossy films, or envelopes) from the top one by one. Further, the present invention relates to a printer which produces a print by feeding sheets of sheet one by one, and more particularly, to the technique of feeding and conveying sheet.
2. Related Art
A feeder provided in a printer is generally known to be classified into a pawl-separation type and a pad-separation type.
As is publicly known, the pawl-separation type sheet feeder comprises pawls which are engaged with the front corners of stacked sheet and a sheet feed roller provided behind the pawls (i.e., in a downstream direction with reference to the direction in which the sheet is fed). The sheet feed roller is rotated so as to deflect the uppermost sheet of the sheet in a position between the sheet feed roller and the pawls. When the deflection of the sheet reaches a predetermined maximum value, the sheet is flipped to thereby separate the uppermost sheet from the next sheet. As a result, only the uppermost sheet is fed.
In contrast, as is also publicly known, the pad-separation type sheet feeder comprises a sheet feed roller and a separation pad. Taking a coefficient of friction between the sheet feed roller and sheet as .mu.1, a coefficient of friction between the separation pad and sheet as .mu.2, and a coefficient of friction between sheets of sheet as .mu.3, the sheet roller and the separation pad are arranged so as to satisfy the relationship of .mu.1>.mu.2 >.mu.3. Sheet is nipped between the rotatable sheet feed roller and the separation pad to be brought into pressed contact with the sheet feed roller, thereby separating the uppermost sheet from the next sheet. As a result, only the uppermost sheet is fed.
In either case, when the rotatable roller comes into contact with the surface of the uppermost sheet and the uppermost sheet is fed, the reverse side of the roller-contacted portion of the uppermost sheet makes slidable contact with the surface of the next sheet. The surface of the next sheet is slightly flawed by the sliding action of the uppermost sheet. If the sheet is, e.g., glossy sheet or a glossy film, the thus-produced flaws become noticeable.
For the case of the pawl-separation type sheet feeder, the portion of the uppermost sheet behind the pawls, i.e., the portion of the uppermost sheet to be deflected (in other words, the flawed protion), is positioned behind sufficient to be deflected, thereby impairing a print area of the sheet.
In contrast, for the case of the pad-separation type sheet feeder, although the front edge of the surface of only the sheet is flawed, the print area is not usually flawed.
Accordingly, the pad-separation type sheet feeder is superior from the viewpoint of the degree of flaw.
However, the pad-separation type sheet feeder has the following difficulties.
For example, as shown in FIG. 34, in a case where a pad-separation type sheet feeder 1 is applied to a printer, supplied sheet P1 is conveyed while being nipped between conveyor rollers 2, 3, and printing means 4 produces a print on the sheet P1. Usually, the sheet P1 still remains in the sheet feeder at a point in time when the conveyor rollers 2, 3 commence conveying the sheet P1.
In contrast, for the case of the pad-separation type sheet feeder, taking the frictional force acting between the sheet feed roller and sheet as f1. the frictional force acting between sheet and the separation pad as f2, and the the separation pad must be brought into pressed contact with each other in such a way as to satisfy the foregoing relationship of .mu.1>.mu.2>.mu.3, i.e., f1>f2>f3. If the sheet feed roller is held in pressed contact with the separation pad at a point in time when the conveyor rollers 2, 3 commence conveying the sheet P1, a rear portion of the sheet P1 is nipped between the sheet feed roller and the separation pad.
Consequently, the sheet P1 is conveyed by the conveyor rollers 2, 3 while it still remains under the load applied by the nipping section (or still being held in a rearwardly-withdrawn state or under a back-tension state) until the rear edge of the sheet P1 passes through the nipping section between the sheet feed roller and the separation pad.
If such a load (or a back tension) is great, the accuracy of sheet-feeding action of the conveyor rollers 2, 4 becomes lower, thereby resulting in a reduction in print quality. For this reason, it is desirable to reduce the load, or the nipping force exerted on the sheet feed roller and the separation pad, to load as small as possible. However, if the nipping force exerted on the sheet feed roller and the separation pad is too small, the next sheet gradually burrows into the nipping section between the sheet feed roller and the separation pad every time the sheet feed operation is repeated, thereby rendering the separation of sheet impossible.
A sheet medium alignment mechanism disclosed in Japanese Patent Application Laid-open No. Hei-7-53062 is intended to solve the foregoing problem.
FIGS. 35A to 35E show the construction and operation of this sheet medium alignment mechanism.
In these drawings, reference numeral 18 designates sheet feed rollers; 24 designates a separation pad; and 22 designates a lever.
As shown in FIG. 35C, the lever 22 is supported by a pivot A in a pivotable manner and is forced clockwise by a cantilever spring 26 which presses an arm 22c of the lever 22.
With this mechanism, as shown in FIGS. 35B to 35E, the uppermost sheet S1 is separated from the next sheet S2 by a nipping section formed between sheet feed rollers 18 and a separation pad 24 as a result of rotation of the sheet feed rollers 18 in a clockwise direction. As shown in FIG. 35D, only the uppermost sheet S1 is supplied. At this time, as shown in FIGS. 35C and 35D, the lever 22 is pressed to a receded position by the sheet S1. Even if the second sheet S2 (and a sheet S3 after the sheet S2) burrows into or attempts to burrow into the nipping section between the sheet feed rollers 18 and the separation pad 24, the lever 22 is pivoted clockwise by the urging force of the cantilever spring 26 immediately after the passage of the rear edge of the sheet S1 through the upper edge of the lever 22. As shown in FIG. 35E, the next sheet S2 (and the sheet S3 after the sheet S2) is forcibly reset to their original positions.
Accordingly, this mechanism seemingly solves the difficulty of separation of sheets owing to the gradual entry of the next sheet into the nipping section between the sheet feed rollers and the separation pad. However, this mechanism suffers from another problem which will be described later (see Problem 1).
If the sheet feed rollers 18 are rod-shaped, the roller is constantly held in pressed contact with the separation pad. Therefore, the sheet feed rollers and the separation pad are susceptible to abrasion.
There is a known sheet feeder which solves this problem, i.e., the abrasion of the sheet feed rollers and the separation pad, and comprises sheet feed rollers each of which has a substantially D-shaped lateral cross section.
FIG. 36 shows a sheet feeder disclosed in Japanese Utility Model Publication No. Hei-8-3396 as one example of the sheet feeder of this type. In the drawing, reference numeral 40 designates sheet feed rollers each of which has a substantially D-shaped lateral cross section and comprises a circular-arch portion 40a and a linear portion 40b.
Reference numeral 41 designates a guide block which supports a shaft 40c of the sheet feed rollers 40.
Reference numeral 42 designates a cassette and incorporates a sheet mounting plate 42a therein. A plurality of sheets of sheet P are loaded on the sheet mounting plate 42a in a stacked manner. Reference numeral 42c designates a spring which forces the sheet P toward the sheet roller 40.
Reference numeral 43 designates a separation pad and is attached to a bracket 48a. The separation pad 43 is on the course of rotation of the circular-arch portion 40a of the sheet feed rollers 40 and is pushed by a spring 44 along a guide 45 toward the sheet feed roller shaft 40c.
Reference numeral 46 designates an idle roller which is attached to the guide block 41 in a rotatable manner; and 47 designates a movable idle roller whose shaft 47a is fitted, in a rotatable manner, into an elongated groove 41a formed in the guide block 41. The movable idle roller 47 is forced toward the separation pad 43 by means of a spring 48 and is in contact with the separation pad 43.
Urging force F2 of the spring 48 is set to become smaller than urging force F1 of the spring 44 of the separation pad 43 (i.e., to satisfy a relationship of F1>F2).
The sheet feeder having the foregoing construction operates in the following manner:
As shown in FIG. 36, when the sheet feeder is in a standby condition, the linear portion 40b of the sheet feed roller 40 is opposite to sheet P, and the sheet feed rollers 40 are kept from contact with the sheet P. Further, since the urging force F2 of the spring 48 of the movable idle roller 47 is set to become smaller than the urging force F1 of the spring 44 of the separation pad. 43, the movable idle roller 47 is pushed in an upward direction by the separation pad 43. As a result, the shaft 47a of the movable idle roller 7 is held in contact with the upper edge of the elongated groove 41a.
At the time of sheet feed operation, the sheet feed rollers 40 rotate in the direction designated by the arrow, and the circular-arch portion 40a comes into contact with the uppermost sheet P1 of the sheet P, whereby the sheet P1 is fed to the separation pad 43. At this time, the second sheet P2 is electrostatically attached to the sheet P1, or frictional force acts between the sheets P1 and P2, and the sheet P2 is sometimes fed together with the sheet P1.
However, the sheet P2 is separated from the sheet P1 by the separation pad 43 in the following manner, whereby only the uppermost sheet P1 is fed.
More specifically, the front edge of the sheet P2 collides with the separation pad 43 and is prevented from advancing. As a result, the sheet P2 is temporarily separated from the sheet P1.
Taking, the frictional force exerted between the circular-arch portion 40a of the sheet feed roller 40 and the sheet P1 as f1, the frictional force exerted between the sheet P2 and the separation pad 48 as f2, and the frictional force exerted between the sheets P1 and P2 as f3, the sheet feed rollers 40 and the separation pad 43 are arranged so as to satisfy the relation ship of f1>f2>f3. Therefore, even if both the sheets P1 and P2 are nipped between the circular-arch portion 40a of the sheet feed roller 40 and the separation pad 43 with the rotation of the sheet feed rollers 40, the sheet P2 is hindered from advancing by the frictional force exerted between the sheet P2 and the separation pad 43. As a result, the sheet P2 is separated from the sheet P1, and only the sheet P1 is fed. Since the separation pad 43 is on the course of rotation of the circular-arch portion 40a of the sheet feed roller 40, the separation pad 43 is pushed downward by the circular-arch portion 40a as a result of its rotation. However, since the movable idle roller 47 is forced toward the separation pad 43 by the spring 48, the separation pad 43 comes into contact with the movable idle roller upon depression, thereby resulting in the separation of the sheets.
The sheet feed rollers 40 perform exactly one rotation, and the sheet feeder returns to the standby condition (the state of the sheet feeder shown in FIG. 36).
Through the foregoing operations, only the uppermost sheet P1 is fed.
With such a sheet feeder, the sheet feed rollers 40 are prevented from being constantly held in pressed contact with the separation pad 43, and consequently the degree of abrasion of the sheet feed rollers and the separation pad is reduced.
Further, since the movable idle roller 47 is kept in pressed contact with the separation pad 43 by means of the spring 48, the next sheet is prevented from entering the nipping section together with the uppermost sheet to a certain extent.
<Problem 1>
In the mechanism shown in FIG. 35, since the lever 22 is pivoted by the urging force of the spring 26 when the next sheet P2 is reset. If the urging force of the spring 26 is small, a risk arises of failure to ensure reliable resetting of the next sheet P2. If the urging force of the spring 26 is increased, the next sheet S2 may be forcibly reset in a reliable manner. However, as shown in FIGS. 35C and 35D, the lever 22 must be pushed to the receded position by the sheet S1 at the time of feeding of the uppermost sheet S1. For this reason, an increase in the urging force of the spring 26 is not desirable. In order to set the lever 22 in such a way as to be pushed to the receded position by the uppermost sheet S1 in the case of the urging force of the spring 26 being increased, a force for feeding of the sheet S1, i.e., the nipping force exerted between the sheet feed rollers 18 and the separation pad 24, must be increased. In this case, the aforementioned original objective of reducing a load (or a back tension) cannot be achieved.
In order to reduce the load (or the back tension) by means of the foregoing existing mechanism, the urging force of the spring 26 must be reduced. If the urging force of the spring 26 is reduced, a risk arises of unreliable resetting of the next sheet S2.
<Problem 2>
In order to enable the previously-described sheet feeder; e.g., sheet feeder shown in FIG. 36, to appropriately feed various types of differently-sized sheet, or sheet having different widths, it is desirable to provide the sheet feeder with a pair of sheet feed rollers 40 and to make at least one of them slidable in accordance with the width of sheet.
Further, in order to enable sheet P to be readily loaded on the sheet mounting plate 42a while the sheet feeder is in a non-sheet-feeding state (or a standby condition), the sheet mounting plate 42 is preferably arranged so as to be separated from the sheet feed rollers 40 against the urging force of the spring 42c (or the sheet mounting plate 42 is moved downward) when the sheet feeder is in a non-sheet-feeding state.
With the foregoing arrangement, the sheet feeder shown in FIG. 36 presents the following problems.
For example, in a case where sheet having a comparatively wide width (e.g., A4-size sheet) is loaded on the sheet mounting plate 42a and sheet having a comparatively narrow width (e.g., B5-size sheet) is loaded in place of the A4-size sheet, the user sets the interval between the pair of sheet feed rollers to a narrow width in accordance with the width of the sheet in advance and loads sheet on the sheet mounting plate. There may be another case where sheet is initially loaded on the sheet mounting plate and the interval between the sheet feed rollers is adjusted to the width of the sheet.
In the case where the user loads sheet on the sheet mounting plate at the outset, the sheet mounting plate 42a still remains in the position separated from the sheet feed rollers 40 at the time of loading of sheet, as previously described. Because of this, the front edge portion of the top sheets (e.g., the sheets P1 and P2) of the loaded sheet P burrows into a clearance C formed between the sheet feed rollers 40 and the separation pad 43, as viewed in the axial direction of the sheet feed roller 40.
If an attempt is made to slide one of the sheet feed rollers 40 in accordance with the width of sheet, the front edge portion of the sheet burrowed into the clearance C comes into contact with the side surface of the sheet feed roller 40 or the side surface of the idle roller 47, or the like, thereby inhibiting smooth sliding action of the sheet feed roller 40. As a result, the sheet feed rollers 40 fail to slide to an optimum position. If the sheet feed rollers 40 are slid forcibly, the front edge portion of the sheet burrowed into the clearance C is nipped between the pair of sheet feed rollers 40 or by the idle roller 47, or the like, thereby rendering the sheet concertinated.
If the sheet is fed in while remaining in the concertinated state, sheet jams will occur, or the sheet will be fed diagonally.
Even if the mechanism shown in FIG. 35 is constructed so as to have the foregoing arrangement, i.e., a pair of sheet feed rollers at least one of which is slidable in accordance with the width of sheet and a sheet mounting plate which is separated from the sheet feed rollers when the sheet feeder is in a non-sheet-feeding state (or a standby condition), the previously-described problems seem not to arise, because the lever 22 is positioned so as to close the clearance formed between the sheet feed roller 18 and the separation pad 24.
However, in practice, another similar problem arises for the following reasons.
As is evident from FIG. 35E, the mechanism shown in FIG. 35 does not have any means for preventing the pivotal movement of the lever 22 in a counterclockwise direction (in a forward direction) in the drawings when the sheet feeder is in a non-sheet-feeding state.
The lever 22 is forced solely by means of the spring 26. Therefore, if sheet is loaded by a force that is sufficient to overcome the urging force of the spring 26, a risk arises of the front edge portion of the uppermost sheet burrowing into the clearance between the sheet feed roller 18 and the separation pad 24 while pivoting the lever 22, thereby imposing a problem analogous to the foregoing problems.
More specifically, if an attempt is made to construct the existing sheet feeder or sheet feeding mechanism in such a way as to enable at least one of a pair of sheet feed rollers to slide in accordance with the width of sheet and to separate the sheet mounting plate from the sheet feed rollers, a risk arises of the front edge portion of the sheet being loaded on the plate burrowing into the clearance formed between the sheet feed rollers and the separation pad when viewed in the axial direction of the sheet feed roller. For these reasons, sheet jams arise, or sheet is fed diagonally.
<Problem 3>
The previously described separation pad type sheet feeder is generally designed in such a way that the sheet is retained in a substantially horizontal state. For example, even in the case of the sheet feeders shown in FIGS. 35 and 36, the sheet is retained in a substantially horizontal state.
For this reason, the existing separation pad type sheet feeder requires a large footprint.
The problem can be solved by arranging the sheet feeder in such a way as to retain sheet in an inclined state. For example, if the sheet feeder is designed so as to retain the sheet at an angle of 45.degree., the footprint occupied by the sheet is reduced to half its original area.
However, it has been difficult to construct the separation pad type sheet feeder in such a way as to retain sheet in an inclined state.
For example, as is evident from the assumption that sheet would be retained in an inclined state (e.g. the sheet is inclined at about 45.degree.) in the sheet feeder shown in FIG. 35, it is possible that the sheet will slide under its own weight if the sheet is retained in an inclined state. As a result, the next sheet (S2), the sheet after the next (S3), or the like, cause an avalanche, thereby rendering the sheet considerably easy to burrow into the nipping section between the sheet feed rollers 18 and the separation pad 24. Particularly for the case of slippery sheet, e.g., sheets for OHP purposes, the sheet is apt to cause an avalanche, thereby rendering the sheet considerably easy to burrow into the nipping section between the sheet feed rollers 18 and the separation pad 24.
For these reasons, even if the lever 22 shown in FIG. 35 is provided for the sheet feeder, a risk may arise of the front edge of the next sheet (S2) having already passed through the front end of the lever 22 when the rear edge of the uppermost sheet (S1) passes the front end of the lever 22. As a result, a risk may arise of reliable separation of sheets becoming impossible.
Even if the sheet feeder shown in FIG. 36 is arranged so as to retain sheet in an inclined state, the next sheet or the sheet after the next may cause an avalanche in an analogous manner. Thereby rendering the sheet considerably easy to burrow into the nipping section between the sheet feed rollers 40 and the separation pad 43. Consequently, the next sheet gradually (or cumulatively) burrows into the nipping section between the sheet feed rollers and the separation pad every time the sheet feeding operation is performed, thereby rendering the separation of the sheet impossible.
It is conceivable that such a problem can be solved by considerably increasing the nipping force exerted on the sheet feed rollers 18 and the separation pad 24 (or the nipping force exerted on the sheet feed rollers 40 and the separation pad 43 and the nipping force exerted on the elastic idle roller 47 and the separation pad 43 in the sheet feeder shown in FIG. 36).
However, if the nipping force is increased, the drive force exerted on the sheet feed rollers must also be increased. Since the previously-described load (or back tension) which is applied to the sheet by the conveyor rollers 2, 3 is considerably increased, the nipping force applied to the sheet by the conveyor rollers 2, 3 must be increased so as to ensure a feed force which is sufficient to overcome the load. Accordingly, a large drive force to drive the conveyor rollers, or the like, is also required, thereby rendering the sheet feeder bulky or resulting in an increase in power consumption. Further, the sheet rollers or the conveyor rollers become more susceptible to abrasion.
In short, it has been impossible to retain sheet in an inclined state and to feed the sheets of sheet one by one without increasing the drive force of various rollers or the back tension even by means of the technique shown in FIG. 35 and the technique shown in FIG. 36.
<Problem 4>
In the event of a plurality of sheets concurrently burrowing into the clearance between the sheet feed rollers and the separation pad or the clearance between the idle roller and the separation pad as a result of occurrence of an avalanche in any one of the previously-described existing sheet feeders, the sheets are integrated into the form of a wedge, thereby resulting in a risk of the uppermost sheet being locked during the course of sheet feeding operation.


In an aspiration flow measurement system, a flow channel is provided for receiving an aspiration fluid flow therethrough. The flow measurement system further includes an aspiration flow measurement chamber and a flow sensor that is configured to generate a raw signal indicative of the rate of fluid flow through the flow channel. A control system is configured to monitor the signals indicating the flow through the flow measurement chamber, and to determine when a value of the raw signal is indicative of a disruption caused by the presence of an air bubble, wherein the control system generates a filtered signal of the flow rate that is exclusive of any signal values that are indicative of a disruption.

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
The flow and flow rate of fluids through an aspiration tube is of interest during operations, including ophthalmic operations. During ophthalmic microsurgery, small probes are inserted into an operative site to remove tissues and fluids may be infused into the operative site through the probes. Infusion fluids may also be aspirated from the site. Surgical cassettes may also be coupled to surgical probes, to provide for collection of aspirated fluids. Measurement of the surgical aspiration flow rate may be valuable in that it can provide for safe control of the ophthalmic surgical equipment. However, passage of air bubbles, among other factors, within the aspiration measurement devices can make measurement of the flow rate difficult to achieve.
Therefore, it would be desirable to incorporate air filtering or diverting means into a disposable surgical cassette to permit accurate measurement of flow rate by removing or greatly reducing any effect of the air bubbles.

Aspiration flow mesurement system with flow signal air bubble filter


A write precompensation amount setting method and apparatus comprise a function detecting the respective head characteristics with an electric current used at an ordinary temperature and a irregular electric current, and a function setting an optimum write precompensation amount at a low temperature according to the detected head characteristics.

1. Field of the Invention
The present invention relates to a write precompensation amount setting method and apparatus, which tune a write precompensation amount of a magnetic disk device, and more particularly, to a write precompensation amount setting method and apparatus for reducing a compensation shift which becomes problematic in a magnetic disk device.
2. Description of the Related Art
When magnetically recorded digital data is reproduced with a magnetic head, a peak shift occurs on a reproduced waveform. This peak shift is caused by a mutual interference with an adjacent bit (magnetized region) when a magnetized region corresponding to a bit array is read with a magnetic head. If the peak shift increases, a read pulse cannot be obtained at a position determined by a data window, which leads to a read error. The peak shift of this type is not too problematic when a recording density is low, but is problematic when the recording density is high. A method of compensating for a peak shift is a tuning method where the phase of a pre-identified bit, when data of a particular bit array whose peak shift is problematic, is recorded. In other words, a method compensating for a write operation (write precompensation).
Conventionally, a write precompensation amount according to an environmental temperature is determined at an ordinary temperature for each head as a drive parameter, and uniformly set for each environmental temperature in normal cases.
FIG. 1 is a flowchart showing the conventional process for setting a write precompensation amount.
Firstly, error rates are measured at ordinary and low temperatures in a test drive (step S1). For example, respective error rates are measured when a write precompensation amount at an ordinary temperature (such as 25 degrees centigrade) with a write current 40 mA, and a write precompensation amount at a low temperature (such as 5 degrees centigrade) with a write current 50 mA are changed between 15 and 30% in steps of 1%.
Next, the write precompensation amounts at the best (minimum) error rates among the error rates measured in step S1 are determined as optimum write precompensation amounts at the ordinary and the low temperatures in the test drive (step S2). For example, if the write precompensation amounts at the lowest error rates at the ordinary temperature of 25 degrees centigrade and the low temperature of 5 degrees centigrade are respectively 20 and 24%, a deterioration amount from 25 to 5 degrees centigrade is determined to be 4%.
Then, an error rate at an ordinary temperature is measured at the time of mass production (step S3). By way of example, each error rate is measured when the write precompensation amount at the ordinary temperature of 25 degrees centigrade with the write current 40 mA is changed between 15 and 30% in steps of 1%.
Furthermore, the write precompensation amount at the lowest error rate among the error rates measured in step S3 is determined to be an optimum write precompensation amount at the ordinary temperature at the time of mass production (step S4). For example, the write precompensation amount at the lowest error rate at the ordinary temperature of 25 degrees centigrade is determined to be 20%.
Lastly, an optimum write precompensation amount at a low temperature is set according to the deterioration amount determined in steps S1 and S2 at the time of mass production (step S5). By way of example, the deterioration amount of 4% from 25 to 5 degrees centigrade, which is determined in step S2, is added to the write precompensation amount of 20% at the lowest error rate at the ordinary temperature of 25 degrees centigrade, so that the write precompensation amount at the low temperature is set as 24%.
However, the environmental temperature characteristic of each magnetic head may vary. Actually, a magnetic head whose write characteristic deteriorates significantly at a low temperature requires a large write precompensation amount. Therefore, a lack of compensation occurs. At the same time, for a magnetic head whose write characteristic is good at a low temperature, over-compensation occurs. Namely, any heads whose characteristics shift from an average head characteristic can possibly cause error rate deterioration. This loss cannot be ignored toward future improvements in the performance of a magnetic disk device, and more accurate tuning has been demanded.

Write precompensation amount setting method and apparatus

Abstract: As a result, a write precompensation amount is corrected according to the characteristics of the normal current and the irregular current, and a write precompensation amount is determined, so that the write precompensation amount with higher accuracy than that with a conventional technique can be determined.


[Object] A cartridge memory according to an embodiment of the present technology is a cartridge memory for a recording medium cartridge, including: a memory unit; and a capacity setting unit. The memory unit has a memory capacity capable of storing management information relating to a second information recording medium configured to be capable of recording information with a second data track number larger than a first data track number. The capacity setting unit is configured to be capable of setting a data storage area limited to a first capacity capable of storing management information relating to a first information recording medium configured to be capable of recording information with the first data track number.

In recent years, magnetic recording media are widely used for applications such as backup of electronic data. As one of the magnetic recording media, for example, a magnetic tape cartridge is increasingly attracting attention as a storage medium for big data or the like because it has a large capacity and can be preserved for a long time.
For example, a magnetic tape cartridge of the LTO (Linear Tape Open) standard is equipped with an RFID (Radio Frequency Identification) tag called a cartridge memory (see, for example, Patent Literature 1). Since the cartridge memory receives the signal magnetic field transmitted from a tape drive (reader/writer) to generate power, it is possible to perform communication with the reader/writer with no power supply. The cartridge memory includes an antenna and an IC chip for communication/recording, and is configured to be capable of reading/writing production management information, usage history, outlines of recorded content, and the like of cartridges and magnetic tapes.

Cartridge memory, recording medium cartridge, and method of producing the same


The present invention relates to a hybridoma cell line producing a PPAR gamma-specific monoclonal antibody, and a method for detecting a PPAR gamma ligand related to the progression of difficult diseases, such as cancer, inflammation and metabolic diseases obesity and diabetes), using the PPAR gamma-specific monoclonal antibody. This PPAR gamma-specific monoclonal antibody and the method for screening a PPAR gamma ligand using the monoclonal antibody will be commercially used for screening a PPAR gamma regulator related to diseases such as inflammatory, cancer and metabolic diseases, and also will serve as an useful tool for analyzing the function of such a ligand.

The protein PPAR (peroxisome proliferator activated receptor) is known as a nuclear receptor. Peroxisome which is an intracellular organelle is involved in oxidation and present in the liver and kidneys at large amounts. Also it oxidizes an intracellular fatty acid to produce peroxides which serve to neutralize toxic substances. In addition, it has a function of decomposing excess hydrogen peroxide into water and oxygen by catalase, an oxidase. A peroxisome proliferator signifies a compound capable of increasing the number of peroxisomes, and includes fat and fatty acid, and fibrate and prostaglandin as hyperlipemia-treating agents.
Nuclear receptors having such peroxisome proliferators as ligands are collectively called PPARs, which are divided into PPAR alpha, PPAR delta/beta and PPAR gamma. As known in the art, PPAR alpha is mainly expressed in the liver, and involved in the oxidation of fatty acids or the neutralization of toxic substances, and related to inflammatory reaction. PPAR delta/beta is found to distribute uniformly and to be involved in embryonic development, and PPAR gamma is known to be involved in the differentiation and accumulation of fat cells.
It was recently found that the expression of PPAR gamma was increased in a differentiation process of a fat cell line into a fat cell, and that expression of PPAR gamma in fibroblast having no differentiation ability resulted in differentiation of the fibroblast into a fat cell. Particularly, PPAR gamma2 is divided into two isoforms and reported to be specifically expressed only in fat cells at large amounts. mRNA of mouse PPAR gamma1 is coded by eight exons, whereas mRNA of PPAR gamma2 is coded by seven exons. The 5′ untranslated sequence of mRNA of mouse PPAR gamma1 is coded by two exons, whereas the 5′ untranslated sequence of PPAR gamma2 and the additional N-terminal amino acids are coded by one exon. The two isoforms are yielded by alternative promoter use and different splicing, and increase the variety of ligands and make tissue-specific expression possible (Zhu Y et al., 1995).
Meanwhile, type 2 diabetes is characterized by the insulin resistance of skeletal muscle tissues, liver tissues and fat tissues, etc. In the early 1980's, among treating agents of type 2 diabetes, glitazones and the like belonging to thiazolidinediones (TZD) were first reported as a drug which allows glucose level to be reduced and insulin resistance to be improved without stimulating insulin secretion in an experimental rat model of type 2 diabetes.
As glitazones, treating agents of type 2 diabetes, are found to be PPRA gamma agonists (Lehmann J M et al, 1995), it is reported that PPRA gamma ligands (agonists) can improve insulin resistance.
This fact seems to prove the therapeutic effect of the PPAR gamma agonists and to suggest the utility of a system for screening diabetes-effective substances by ELISA, which was established by the present inventors.
Meanwhile, in order to examine how the activity of PPAR gamma in fat cells influences the metabolism of glucose in the muscles and liver, the mechanisms of PPAR gamma agonists as agents for improving diabetes will now be described. First, PPAR gamma protein in fat cells is known as regulating the release of endocrine signal molecules influencing the metabolism of glucose in the muscles and liver, such as cytokine TNF-α or leptin. Expression of the two signal molecules is inhibited by the PPAR gamma agonists in fat cells, and it was found that TNF-α resulted in the increase of insulin resistance and leptin interfered-with insulin signal transmission in any cells (Cohen B. et al., 1996; and Muller G. et al., 1997). This seems to increase insulin resistance. Thus, insulin resistance caused by such two signal molecules can be improved by the PPAR gamma agonists.
Second, there is the antihyperglycemic effect of PPAR gamma agonists. Generally, glucose and fatty acids compete with each other for an energy substrate in muscles, so that the increase of the amount of fatty acids results in the decrease of glucose consumption. Thus, it is believed that the increase of free fatty acids and the increase of glucose synthesis or gluconeogenesis are connected with each other. In this case, the PPAR gamma agonists stimulate fat cells to absorb and store fatty acids, thereby reducing the amount of circulating triglycerides and free fatty acids. Furthermore, the PPAR gamma agonists are known as having an indirect effect on glucose metabolism, reducing the level of fatty acids in the muscles or liver (Martin G. et al., 1998). Accordingly, the PPAR gamma agonists stimulate fatty acid flow from the muscles or liver to white fatty acids and show a dramatic effect on energy expenditure, thereby causing the reduction of gluconeogenesis in the liver and the increase of glucose consumption in muscles.
Finally, PPAR gamma is also expressed in the muscles and liver at a lower expression level than in fat cells and can show an effect of improving diabetes by its direct activation. Namely, it is reported that treatment of experimental rats deficient in fat tissues with troglitazone as a PPAR gamma agonist reduces hyperglycemia and increases insulin sensitivity. This mechanism can be regarded as the role of PPAR gamma agonists generated by a pathway separate from fat cells (Burant C F et al., 1997).
And the PPAR gamma agonists show a direct or indirect effect in various tissues including the muscles and liver.
Moreover, for atheromatous lesions, PPAR gamma is known as being expressed in macrophages including foam cells at a high level.
The foam cells generally means cholesterol-laden cells converted from macrophages embedded in the inner arterial wall. This conversion of the macrophages into the foam cells is regarded as a definite symptom of occurrence of arteriosclerosis.
The conversion process of the cells is known as having a connection with the internalization of oxLDL particles by scavenger receptors, such as CD36 (cell adhesion molecule) and scavenger receptor-A. It was recently reported that PPAR gamma was also closely connected with this process (Tontonoz P. et al., 1998).
For example, it is known that treatment of a human acute monocytic leukemia cell line (THP-1) with PPAR gamma and RXR alpha (retinoid X receptor alpha) agonists induces the expression of PPAR gamma2 and CD36 and promotes the absorption of oxLDL, and treatment of the aorta of experimental rats with the PPAR gamma agonist increases the expression of CD36. Particularly, 9-HODE and 13-HODE, two components of oxLDL, were found to be PPAR gamma agonists. Accordingly, PPAR gamma is an important component of oxLDL-PPAR gamma-CD36 contributing to the accumulation of lipids induced from oxLDL by macrophages. These results indicate that PPAR gamma agonists have the possibility of promoting the formation of foam cells, but clinical data show that glitazone protects patients with type 2 diabetes from arteriosclerosis which can frequently secondarily occur in these patients. This is because treatment of low density lipoprotein (LDL) receptor-deficient rats (arteriosclerosis model) with rosiglitazone and GW784 is known as inhibiting the formation of atheromatous lesion in spite of the increase of CD36 expression.
According to recent studies, it was found that the release of cholesterol from macrophages was controlled by ABCA1 (ATP binding cassette A1), a member of ATP binging cassettes (ABC) of energy-dependent transporter proteins, in which ABCA1 is mutated in patients with tangier disease caused by cholesterol accumulation in macrophages and other reticuloendothelial cells. The transcription of an ABCA1 gene is regulated by a nuclear oxysterol receptor LXR (liver X receptor), and PPAR gamma and LXR agonists act together to induce the expression of ABCA1 and to promote the release of cholesterol from macrophages and THP-1 cell lines induced from rat embryonic stem cells (Chawla A. et al., 2001).
Furthermore, the ABCA1 gene is known as a direct target gene of a PPAR gamma/RXR heterodimer and causes the expression of LXR-alpha when the activity of PPAR gamma is increased. This leads to the increase of ABCA1 expression and the release of cholesterol. In addition, PPAR gamma is known to regulate the introduction and release of cholesterol esters in macrophages. By this effect, oxLDL will be removed which increases the release of free cholesterol introduced to the liver, and causes aortic lesions by absorption into macrophages. Particularly, the PPAR gamma agonists seem to interfere with the development arteriosclerosis in vivo by producing HDL (high density lipoprotein) in the human and increasing the release of cholesterol from macrophages and endothelial cells.
Moreover, there is the broad role of PPAR gamma in the regulation of inflammatory reaction of monocytes/macrophages.
Treatment of PPAR gamma including 15d-PGJ2 and glitazone, with monocytes or macrophages, reduces the expression of pro-inflammatory cytokine such as TNF-alpha and IL-6 and inhibits the activity of macrophages. However, the PPAR gamma agonists induce an effect of inhibiting inflammatory reaction at a different concentration from a concentration required to activate PPAR gamma in cell-based assays. In addition, any potential PPAR gamma agonists have no effects, but 15d-PGJ2 is the most powerful inhibitor against the cytokine production of monocytes or macrophages in vitro. This suggests that the anti-inflammatory effect of the PPAR gamma agonists can be mediated by PPAR-independent mechanism. This hypothesis is supported by several recent studies. Namely, it was found that glitazone inhibited cytokine production in rats treated with LPS (lipopolysaccharide) and that several different PPAR gamma agonists (15D-PGJ2 and rosiglitazone) inhibited cytokine production even in embryonic stem cells having PPAR gamma+/+ or PPAR gamma± or PPAR gamma−/−, as in macrophages.
Meanwhile, 15d-PGJ2 was recently found to inhibit NF-κB activity (Rossi A. et al., 2000; and Straus D. S. et al., 2000). NF-κB causes acute inflammatory reaction by the covalent modification of its DNA-binding domain and IκB kinase as its regulatory subunit. This suggests that PPAR gamma is not substantially effective against acute inflammations caused by leucocytes.
Furthermore, hypertension is one of metabolic defects which often accompany obesity and type 2 diabetes, etc. Its pathogenesis is complex and connected with blood pressure dysregulation, insulin sensitivity, vascular function, and lipid metabolism.
Recent genetic analysis shows that a PPAR gamma dominant negative mutant is connected with severe hypertension Treatment of an animal model of hypertension with PPAR gamma agonists shows low blood pressure, but it is not yet known that the PPAR gamma agonists are involved in a mechanism forming the basis of an anti-hypertensive effect. However, the fact glitazone reduces blood pressure in the human with no diabetes and an animal model of hypertension having no connection with insulin resistance indicates that the anti-hypertensive effect of PPAR gamma agonists is independent of insulin-sensitizing actions.
Since PPAR gamma is expressed in intra-vascular endothelial cells, the PPAR gamma agonists are considered as improving hypertension by regulating the expression of vascular factors connected with the maintenance of vascular tone, such as type C nutriuretic peptide, endothelin, and plasminogen activator inhibitor-1 (Itoh H. et al., 1999).
Furthermore, the proliferation inhibition and pro-differentiation effects of the PPAR gamma agonists suggest that these compounds can be used as an agent for inhibiting the proliferation of de-differentiated tumor cells. This hypothesis supports the experimental results showing that transplantation of BNX triple immuno-deficient nude mice with breast cancer cells (Elstner E. et al., 1998) and prostate tumor cells (Kubota T. et al., 1998) followed by treatment with TZDs inhibits the proliferation of such tumor cells.
These effects show that a differentiation program according to the result of PPAR-mediated activation can be used even in nonadipogenic lineage colonic cells and inhibits the development of cancer. In contrast, when a transformed experimental mouse deficient in one copy of a gene coding for an APC (adenomatous polyposis coli tumor suppressor is treated with PPAR gamma agonists of a significantly higher amount than one required to increase insulin activity, the PPAR gamma agonists promote the development of colonic tumor (Lefebvre A. M. et al. 1998). A human colon cancer cell line studied by Sarraf and his research team has both normal and malfunctioning APCs, and it is considered that many unknown factors required for colonic cell proliferation in an experimental rat model are involved therein.
Furthermore, a recent study conducted by Pilot showed that administering the PPAR gamma agonists to patients with solid liposarcoma caused antineoplastic pro-differentiation. These agonists reduce the proliferation rate of cancer cells, and thus, it is expected that they will make the progression of this disease slow. In any human colon cancers, it was observed that functions of PPAR gamma were lost due to the PPAR gamma mutation (Sarrf P. et al., 1999). The PPAR gamma agonists induce growth arrest and also the synthesis of different markers of human colon cancer cells in cell culture. This discovery suggests that PPAR gamma inhibits cellular transformation.
Moreover, it is found that the PPAR agonists can be used as inhibitors against angiogenesis, a process necessary for solid-tumor growth, and a metastasis process. Thus, such evidences show that PPAR gamma activation inhibits the growth and development of cancer, and PPAR gamma ligands or agonists will provide a new aim for therapeutic application.
Meanwhile, immunoassays are used for detecting such substances.
Generally, immunoassays using antigen-antibody reaction are known as methods of qualitatively and quantitatively analyzing a biological substance to be measured, in which a specific antibody to an antigen substance to be measured is made such that it can be bound to the antigen, and the binding of the antibody to the antigen is measured with various labels which can recognize and measure the antigen-antibody complex with a device.
Immunoassays of biological substances which have been used till now can be divided according to the kind of used labels into radioimmunoassay (RIA) using radioactive isotopes as labels, and non-radioactive immunoassays, including enzyme-linked immunosorbent assay (ELISA) using enzymes or fluorescent substances as labels, and fluorescence enzyme immunoassay (FEIA).
The radioimmunoassay among such immunoassays is widely used which shows high sensitivity and is carried out in a precise, simple, easy and rapid manner. Also it has another advantage in that instruments, such as gamma and beta counters, which can be used in this method, are not so expensive.
However, the greatest shortcoming of the immunoassay using radioactive isotopes is that radioactive wastes are released at large amounts. Also this immunoassay is disadvantageous in that the amount of use and the kind of radioactive isotopes are limited by regulations.
In order to solve such problems, enzyme-linked immunosorbent assay (ELISA) is used which is divided into direct ELISA and indirect ELISA according to a labeling type.
Direct ELISA is a way of conducting direct labeling to an antibody or an antibody fragment by a crosslinker, and indirect ELISA is a way of binding hapten to an antibody and conducting measurement using a label recognizing this complex.
Examples of the crosslinker which is used in the direct ELISA includes N,N′-orthophenylenedimaleimide, 4-(N-maleimidomethyl)cyclohexane-N-succinimide ester, 6-maleimidohexane-N-succinimide ester, 4,4-dithiopyridine and the like. Examples of hapten which is used in the indirect ELISA include biotin, dinitrophenyl pyridoxal, fluoresamine and the like, in which biotin uses avidin or streptoavidin as a recognition ligand.
Horseradish peroxidase is mainly used as an enzyme in ELISA, because it can react with many substrates and can be easily bound to an antibody.
In order to verify a labeled enzyme, horseradish peroxidase uses hydrogen peroxide (H2O2) as a substrate solution, and 2,2′-azino-di-[3-ethylbenzothiazoline sulfonic acid] ammonium salt (ABTS), 5-aminosalicylic acid, orthophenylenediamine, 4-aminoantipyrine, or 3,3′,5,5′-tetramethylbenzidine as a color developer. Also, alkali phosphatase employs orthonitrophenyl phosphate or paranitrophenyl phosphate as a substrate, and β-D-galactosidase uses fluorescein-di-(β-D-galactopyranoside) or 4-methylumbellifery as a substrate.
Meanwhile, if a substance immobilized to a plate is an antibody, ELISA is also called a sandwich ELISA.

Monoclonal antibody specific for PPAR gamma, hydridoma cell line producing the same, and method for detecting regulator related to diseases, including inflammation, cancer and metabolic diseases, using the same

Korea Research Institute of Bioscience and Biotechnology


A device is disclosed to draw off or store viscous mass which is discharged from a process for example as a result of exothermal events. The device contains at least one unit which has one inlet for the viscous mass and one outlet and is at least partly filled with a non combustible liquid inert to the viscous mass. The unit can be in the form of a pipe or a receptacle. Preferably several units in the form of a pipe can be connected one with the other respectively with a unit in the form of a receptacle. The solution discharged can then be transported via the pipes to the receptacle.

This invention relates to a facility to draw off or store viscous mass which is discharged from a process for example as a result of exothermal events.
The invention has further reference to the use of the device in accordance with the invention to draw off or store solutions of cellulose in an aqueous amine oxide discharged from a process to produce cellulosic moulded bodies for example as a result of exothermal events and a process to draw off and store solutions of this kind.
It is known that when transporting viscous mass in chemical or physical processes safety precautions are taken whereby in the event of operational malfunctions the masses are in part discharged from the means of transport.
This covers in particular processes for the production of cellulosic moulded bodies from solutions of cellulose in an aqueous tertiary amine oxide particularly N-methyl-morpholine-N-oxide (NMMO). These processes are known as the "Lyocell process" or the "amine oxide process".
One problem when producing cellulosic moulded bodies by dissolving the cellulose in a mixture of NMMO and water consists in the stabilisation of mouldable solutions obtained in this way. It appeared that when dissolving the cellulose in NMMO the cellulose begins to decompose which leads to an undesirable reduction in the degree of polymerisation of the cellulose and the formation of low molecular decomposition products when the solution is subjected to a thermal load for longer periods of time at temperatures above 100.degree. C.
Moreover, amine oxides, and NMMO in particular, have a limited thermo-resistance which varies depending on the structure. The monohydrate of NMMO melts at temperatures of approximately 72.degree. C., the anhydrous compound melts at 171.degree. C. If the monohydrate is heated strong discolouring occurs at temperatures as of 120/130.degree. C. Temperatures of this kind are quite common with processes to manufacture cellulosic moulded bodies. As of 175.degree. C. strong exothermal reactions occur which can lead to an explosive procedure. In the course of these reactions NMMO is thermally decomposed mainly to N-methyl-morpholine, morpholine, formaldehyde and CO.sub.2.
Since the compounds which form at the prevailing temperatures tend in general to be gaseous high pressures arise with the exothermal decomposition of NMMO which can lead to damage to apparatus parts.
To be able to draw viscous mass off from the process in the event of operational malfunctions, safety apparatuses are know from the state of the art, as are for example described in DE 18 00 061, PCT-WO 94/08162 or PCT-WO 97/08482.
The expert is now faced with the task how this discharged viscous mass can be further drawn off or stored. This is particularly true of mass which congeals when it cools down and which can, therefore, no longer be pumped or only be pumped with difficulty, such as for example solutions of cellulose in tertiary aqueous amine oxides.
EP-A 0 626 198 suggests a cylindrical shaped receptacle which has an entry opening for a congealing material drawn off from the process and at least two entrance openings. By opening the two entrance openings the material can be pushed from one of the two entrance openings to the other and removed from the receptacle in this way.
This apparatus has the disadvantage that the drawing off of a congealed viscous mass from a receptacle like this in the way described is very complicated since the mass settles down on the receptacle wall when congealing and has, therefore, to be scratched off. Moreover, the known apparatus has the disadvantage that the mass drawn off from this process has to be transported across long distances through pipes to the receptacle. The mass can thereby already congeal in the pipes thus leading to blockages.

Device for draining or storing viscous materials


In a device for guiding and tensioning supply lines for working tools movable along a straight guide, e.g. supply lines of a hydraulic hammer drill on an advance mounting, the advance of the working tool is implemented by means of a revolving transport chain driven by a sprocket wheel, and the supply line(s) are guided between the connections on the fixed guide and the connections on the working tool by a tension roller which causes a deflection about 180° and is movable in advance direction downstream the working tool conjointly therewith in the same direction but at half the advance speed, wherein the tension roller is slidably guided on the guide for the working tool transversely to its rotation axis, and wherein a pinion engages the transport chain for driving the movement of the tension roller and interacts with a fixed chain on the opposite side. To realize a controlled movement of the tension roller in both direction, a further transport wheel (14) for the advancement of the tension roller (8) is mounted onto the shaft (23) of the pinion (22) that engages the transport chain (4), for interaction with a fixed chain, a rack, a fixed traction rope, or the like.

The invention relates to a device for guiding and tensioning supply lines for working tools movable along a straight guide, e.g. supply lines of a hydraulic hammer drill on an advance mounting, wherein the advance of the working tool is implemented by means of a revolving transport chain driven by a sprocket wheel, and the supply line(s) are guided between the connections on the fixed guide and the connections on the working tool via a tension roller which causes a deflection by about 180° and is movable in advance direction downstream the working tool conjointly therewith in the same direction but at half the advance speed, wherein the tension roller is slidably guided transversely to its rotation axis on the guide for the working tool, and wherein the drive for the movement of the tension roller includes a pinion which engages the transport chain and interacts with a fixed chain on the opposite side.
According to a known design, the tension roller is guided via a tackle of the block-and-pulley type with loose rope pulley, wherein the loose pulley controls the movement of the tension roller. The drawback of such a design is the susceptibility of tackles to fail, in particular when subjected to rough handling in the area of such tools. Moreover, a tackle control can be actively controlled only in one direction whereas means for retraction and maintaining the tackle taut must be provided in the other direction.
The afore-described design is disclosed in U.S. Pat. No. 3,973,634, with the pinion, which engages the transport chain, engaging with its region that is opposite to the area of engagement in the transport chain in the fixed chain so that only few engaging teeth of the pinion are available to absorb the entire load.

Device for guiding and tensioning supply lines


A method for providing enhanced programming to an entertainment module where the display of the enhanced programming is prepared remotely from the entertainment module. The method includes a step for analyzing a programming transmission stream deliverable to an entertainment module, remotely from the entertainment module, to identify whether the transmission stream includes at least one enhanced programming control signal. In the event that the transmission stream includes at least one enhanced programming control signal, a step for preparing, remotely from the entertainment module, a visual representation of the enhanced programming based upon the at least one enhanced programming control signal. Following preparing the enhanced programming by the preparing step, a step for delivering the visual representation of the enhanced programming to the entertainment module.

1. The Field of the Invention
The present invention relates to systems and methods for providing viewers with an enhanced programming experience. More specifically, the present invention relates to giving a viewer an enhanced programming experience while remotely preparing the enhanced programming in accordance with the selections of the viewer.
2. The Prior State of the Art
For numerous years, homes, offices, and other buildings have accessed television programming through airwave broadcasts, cable providers, satellite transmission, and other communication channels. Televisions provide viewers with a varied assortment of entertainment, news, and educational programming. From the first broadcasts to current television programming, viewers gather a wealth of knowledge, while being entertained. With advances in communication technology and computer systems in recent years, television broadcast viewers no longer are limited to merely watching a television screen. Instead, television broadcast viewers may watch programming on a computer monitor or display, while performing a variety of other tasks, such as word processing, surfing the Internet, playing games, and the like.
Of particular interest, in recent years there has been an explosion with the availability of enhanced programming experiences associated with traditional television broadcast programming. Such enhanced programming experiences allow viewers to interact with or "feel" that they have become part of the television broadcast. For example, the enhanced programming may allow a viewer to "play-along" with participants in a game show by simultaneously answering questions and simulating accumulating points, money, prizes, and the like. Additionally, the current enhanced programming experiences allow viewers to obtain a more thorough understanding of a particular television broadcast. This may be achieved by connecting with a web site that has information relevant to the television broadcast, such as, for example, connecting to a sports related web site to obtain a baseball player's statistics.
Numerous attempts have been made to provide such enhanced programming or interactivity in a straightforward and efficient manner. From the inception of enhanced programming, manufacturers and providers have attempted to develop hardware, such as set-top boxes, and associated software to give a television broadcast viewer an interactive experience, whether the experience eliminates the television broadcast or combines enhanced programming with the television broadcast. The capabilities of each set-top box may vary from complex to unsophisticated set-top boxes. The more complex set-top boxes render Hypertext Mark-up Language (HTML) documents, storing large quantities of enhanced programming data and files, and providing the viewer with an enhanced programming experience. The less complicated set-top boxes ("low-end" set-top boxes) may only be capable of providing the viewer with the number of the television channel currently watched with no enhanced programming content.
With reference to FIG. 1, depicted is a schematic representation of an existing system for providing viewers with an enhanced programming experience using complex advanced receivers or set-top boxes. As shown, a system 10 includes a cable or satellite provider head end 12. The head end 12 represents the cable or satellite provider's hardware and/or software components or modules that receive broadcast programming. For example, head end 12 receives broadcast programming, as represented by the video-in line, and delivers the broadcast programming to an advanced receiver 14, such as an advanced set-top box. The advanced receiver 14 demodulates the signal received from head end 12 and delivers a demodulated signal to a display device 16 that displays the broadcast programming to a viewer.
Additionally, head end 12, through a proxy server 22, is capable of retrieving enhanced programming content from a web server 20 via a network 18. The enhanced programming content can be retrieved and delivered to advanced receiver module 14 before the enhanced programming content is to be displayed to the viewer or can be retrieved by proxy server 22 upon receiving a request from advanced receiver module 14 for such enhanced programming content.
In either case above, advanced receiver module 14 is capable of identifying the availability of enhanced programming content and notifying the viewer of such availability. One manner by which advanced receiver module 14 identifies the availability of enhanced programming content is to track metadata included within the broadcast programming that indicates when enhanced programming content is to be viewed.
While these techniques of providing enhanced programming content to viewers have been used successfully with relatively sophisticated set-top boxes, there are millions of existing, low-end set-top boxes that are not compatible with conventional methods for displaying enhanced programming content. Moreover, because of cost constraints, many more low-end set-top boxes are manufactured each year. Viewers using such low-end set-top boxes have been unable to view enhanced programming content without replacing their set-top boxes, which can be prohibitively expensive for many viewers.
In light of the above, it would be desirable to have a system that allows low-end set-top boxes and receivers to provide a viewer with an enhanced programming experience, thereby limiting the need for the viewer to purchase more complex and expensive set-top boxes and receivers.

Performing server side interactive television


A system and method for actuating a critical aircraft system via a virtual guarded switch includes a touchscreen-based Virtual Guarded Switch (VGS) used to replace physical guarded switches. Aircraft systems display the VGS on traditional touch screen displays either via pilot selection or automatically as a result of an abnormal condition. The VGS maintains protection against inadvertent touchscreen activation while remaining familiar, quick, and easy to understand and use.

Traditionally, switches controlling aircraft systems critical to flight safety are guarded by a removable physical cover which keeps the critical switch from being inadvertently actuated causing irreversible consequences. Examples of such switches include engine fire suppression, generator disconnect, and hydraulic shut-off valves. A pilot must physically raise the cover before the switch is available for function.
A traditional toggle switch may be guarded by a "red guard" spring loaded to remain in each of a covered position enclosing the toggle switch and an open position once opened. A traditional press button switch may also be similarly guarded by a hinged cover removable by the pilot. Some hinged covers may be clear for visualization of the switch underneath while some covers remain opaque.
As flight deck technology evolves to include a reduced number of physical switches and more touchscreen-based functionality, the risk of inadvertent activation has the potential to increase. Without protection, an unguarded touchscreen switch may be easily actuated. Additionally, a human factors consideration may include guarded switches typically used during abnormal or emergency situations. In these emergency situations, familiarity, speed, and ease of operation may be highly desired.
Therefore, a need remains for a system and related method which may overcome these limitations and provide a novel solution to presenting a virtual guarded switch (VGS) via touchscreen enabling pilot action to remove the virtual guard and actuate a system associated with the VGS.


A turbine may include a turbine housing having an inlet opening and an outlet opening, and defining a housing interior space configured to be subjected to a through-flow of exhaust gas from an internal combustion engine. A turbine rotor may be rotatably mounted in the turbine housing about an axis of rotation defining an axial direction. An exhaust gas sensor may be arranged in a measurement space of the turbine housing the exhaust gas sensor configured to determine at least one part of a gas component of the exhaust gas carried in the turbine housing. A feed line may be arranged in the turbine housing having a feed opening and a discharge line arranged in the turbine housing having a discharge opening for feeding and discharging exhaust gas at least one of in and out of the measurement space.

In motor vehicles, the exhaust gas generated by an internal combustion engine is frequently re-treated by means of an exhaust gas turbocharger, wherein such an exhaust gas turbocharger for this purpose can be connected to the exhaust line of the internal combustion engine. In addition, the air-fuel ratio of the exhaust gas is controlled in internal combustion engines in that said exhaust gas is sensed with the help of a suitable exhaust gas sensor which is attached in the exhaust tract of the internal combustion engine. Control can take place in the known manner such that the air-fuel ratio sensed by means of the exhaust gas sensor is brought into agreement with a predetermined set value.
Decisive for an optimal function of the exhaust gas sensor is that the latter is attached in a suitable location of the exhaust gas tract so that defective sensor values of the exhaust gas sensor for example due to steam contained in the exhaust gas, which condenses into condensate on the exhaust gas sensor, are avoided. In the case that in the motor vehicle using the internal combustion engine both an exhaust gas turbocharger as well as a catalytic converter unit for cleaning the exhaust gas generated by the internal combustion engine are employed, such an exhaust gas sensor is usually arranged in a region between the exhaust gas turbocharger and the catalytic converter unit. Because of the relatively large thermal mass of the exhaust gas turbocharger, a relatively long period of time is required after a start-up of the internal combustion engine until the exhaust gas tract including exhaust gas turbocharger and (if present) catalytic converter unit in the internal combustion engine have an adequately high temperature so that it is ensured that steam contained in the exhaust gas cannot condense into condensate and lead to undesirable measurement errors for example because of an undesirable wetting of a measurement ceramic of the exhaust gas sensor with condensed steam.
A further disadvantage of conventional exhaust gas sensors, which are directly attached in the intake to the turbine of the exhaust gas turbocharger to avoid the abovementioned problems consists in that it can be damaged because of a thermal overload (thermal shock).
DE 10 2007 021 763 A1 relates to a turbine of a turbocharger, which is arranged on an exhaust gas passage. The turbine comprises an exhaust gas sensor, which is attached downstream and in the vicinity of the turbine of the exhaust gas turbocharger. The structural element of the exhaust gas sensor in this case is arranged on or in the vicinity of an outlet axis of an outlet channel of the turbine of the exhaust gas turbocharger.
DE 10 2009 046 391 A1 describes a method for operating an exhaust gas sensor exposed to the exhaust gas in the exhaust gas tract of an internal combustion engine, according to which exhaust gas is guided to the exhaust gas sensor by means of a capillary. To achieve a robust method, which ensures a highly dynamic measurement of the exhaust gas sensor and does not require any additional structural elements, the exhaust gas flowing to the exhaust gas sensor via the at least one capillary is branched off from the exhaust gas upstream of a stagnation pressure source generating an exhaust gas stagnation pressure.

Turbine for an internal combustion engine


This invention offers an improved hands-free device for coupling to radio devices having mute and audio inputs. The invention couples serially between the radio and a portable electronic device such as a mobile telephone. The invention facilitates the delivery of appropriate audio signals to the radio. The invention also senses the activity of the portable electronic device and actuates a mute signal upon sensing such activity. The mute signal causes the radio to switch the input to its loudspeakers from a received signal to the audio being delivered by the invention from the portable electronic device. In so doing the invention offers an easy to install, inexpensive hands-free unit that takes advantage of the high fidelity loudspeakers in the automotive stereo system.

1. Technical Field
This invention relates generally to accessories for mobile telephones, and more specifically to an apparatus for interfacing a mobile telephone with an existing audio system for hands-free use of the mobile telephone.
2. Background Art
Many cities and municipalities have recently passed ordinances restricting the use of cellular telephones while driving. For example, §588.03 of Westchester County, N.Y. states, "No person shall utilize a cellular phone while operating a motor vehicle on any public street or public highway within the County of Westchester." Such laws generally include exceptions for cellular telephones equipped with "hands-free" devices. The Westchester code, for instance, states, "this law shall not be construed to prohibit a person operating a motor vehicle from utilizing a cellular phone equipped with a hands-free device." Simply put, a hands-free device is any device or technological advance that allows the user of a cellular phone to utilize the cellular phone without holding it in his or her hand.
In response, manufacturers of audio accessories have developed different types of hands free devices. One example, as advertised on late night television, is a unit that includes a self-contained speaker that is coupled to the earpiece of the phone. In other words, the phone is held in a clamp and a microphone is positioned over the earpiece. When audio is emitted from the earpiece, the microphone senses the audio, amplifies it, and couples it to a two-inch loudspeaker disposed in the hands-free unit. When the user talks, the system relies on the microphone in the phone to pick up the user's voice.
The problem with this type of solution is that the audio is typically of poor quality. To begin, the hands-free microphone coupled to the phone's earpiece picks up much background noise. When this is amplified, the audio produced by the self-contained speaker is often distorted. Next, as the microphone in the cellular phone is designed for near-field use, it sometimes will not pick up the user's voice where the user is far away. Consequently, the transmitted audio from the cellular phone to the receiving caller can be very poor.
As most cars are equipped with high fidelity stereo systems, other manufacturers have found creative ways to employ the stereo loudspeakers in hands-free devices. For example, U.S. Pat. No. 6,163,711, issued to Juntunen et al., discloses a method of coupling a hands-free device to a stereo by modulating the telephone audio with AM or FM radio signals. When the hands-free device is coupled to the phone, the hands-free receives the audio signal and converts it to a FM signal that is, in turn, broadcast in the near field of the car stereo. The user simply turns to the preset "hands-free station" to hear the phone audio on the stereo loudspeakers.
The problem with this approach is two-fold: First, the FM signal broadcast by the hands-free unit is not localized to the car. Thus, if someone stops adjacent to the user at a red light, the other person may eavesdrop on the user's call by simply tuning to the proper radio station. Second, the user must physically tune the radio anytime a call is received. As anyone with an analog-tuning radio knows, this can be both time consuming and distracting.
A third approach is to couple the hands-free device between the stereo and the loudspeakers, as disclosed in U.S. Pat. No. 6,134,456 issued to Chen. In this system, a device is coupled between the stereo and the speakers. When a call is received, the device breaks the connection from the radio and makes a connection to the phone. The audio from the phone is then broadcast through the loudspeakers.
The problem with this system is that it is difficult to install. It requires that the power-carrying loudspeaker cable be severed and then reattached through the device. As loudspeaker wires often run through the sides and undercarriage of the car, this sometimes requires cutting of metal and plastic to reach the wires. The installation is almost always done professionally and is quite expensive.
There is thus a need for an improved hands-free device for cellular phones.

Electronic audio accessory for use with automotive stereo loudspeakers