Disclosed is a belt tooth portion 11 of a toothed belt 8 incorporated in a toothed belt power transmission apparatus for use in equipment for business use. The belt tooth portion 11 comprises tooth root portions 12 formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline C2 in the tooth width direction, power transmission portions 13 formed of circularly arcuate surfaces of convex profile which contiguously adjoin the tooth root portions 12 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, tooth tip portions 14 formed of circularly arcuate surfaces which contiguously adjoin the power transmission portions 13 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, and a tooth crest surface 15 formed of an approximately flat surface which interconnects the tooth tip portions 14. The maximum pressure angle xcex8B at a connection point of the power transmission portion 13 and the tooth root portion 12 is set at from 15 degrees to 25 degrees. As a result of such arrangement, the nonuniformity of velocity of the toothed belt 8 is reduced as low as possible, thereby providing improvement in the printing accuracy and image quality of equipment for business use.

The present invention relates to a toothed belt, to a toothed belt power transmission apparatus, and to business equipment using such a toothed belt power transmission apparatus. The present invention belongs particularly to the technical field of reducing the nonuniformity of belt velocity, i.e., the variation in belt velocity.
Such a type of toothed belt has been known in the art. In the past, toothed belts having belt teeth of trapezoidal profile were used. However, for the achievement of higher power transmission and for the further reduction in noise, belts with a tooth profile having flank surfaces of convex profile have been proposed. Such a type of belt has now been used extensively nowadays. One of such tooth profiles is shown in Japanese Unexamined Patent Application Gazette No. S50-42252, which is known in the art as the STPD tooth profile. The other tooth profile is shown in Japanese Unexamined Patent Application Gazette No. S59-89852, which is known in the art as the HTD-II tooth profile. The former tooth profile, i.e., the STPD tooth profile, has been put to practical use (for example, SUPER TORQUE SYNCRO BELT, a product of BANDO CHEMICAL INDUSTRIES, LTD.). The latter tooth profile, i.e., the HTD-II tooth profile, has been also put to practical use (for example, POWER GRIP GT BELT, a product of UNITTA COMPANY). Further, Japanese Unexamined Patent Application Gazette No. S64-74341 shows and proposes a toothed belt for the purpose of accurate location drive of movable parts incorporated in a business machine. More specifically, as shown in FIG. 17, a plurality of belt tooth portions 11xe2x80x2, 11xe2x80x3, . . . (only one of which is shown in the figure) are provided along a land line LL of a main body 9xe2x80x2 of a belt 8xe2x80x2 at their fixed pitch. Each belt tooth portion 11xe2x80x2 comprises tooth root portions 12xe2x80x2 formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline C2 in the tooth width direction, power transmission portions 13xe2x80x2, 13xe2x80x2 formed of circularly arcuate surfaces of convex profile which contiguously adjoin the tooth root portions 12xe2x80x2, 12xe2x80x2 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, and tooth tip portions 14xe2x80x2, 14xe2x80x2 formed of circularly arcuate surfaces which contiguously adjoin the power transmission portions 13xe2x80x2, 13xe2x80x2 and are arranged symmetrically with each other in respect to the tooth width direction centerline C2, wherein these tooth tip portions 14xe2x80x2, 14xe2x80x2 are interconnected by a tooth crest surface 15xe2x80x2 formed of a flat surface. When the toothed belt 8xe2x80x2 is in static meshing engagement with a toothed pulley 1xe2x80x2, the tooth root portion 12xe2x80x2 of each of the belt tooth portions 11xe2x80x2 substantially comes into contact with a tooth top arc portion 4xe2x80x2 of a pulley tooth groove portion 3xe2x80x2. The backlash of the belt tooth portion 11xe2x80x2 at the pulley tooth groove portion 3xe2x80x2 gradually increases from the tooth root portion to the tooth tip portion of the belt tooth portion 11xe2x80x2 and the depth of the pulley tooth groove portion 3xe2x80x2 exceeds the height of the belt tooth portion 11xe2x80x2. In this prior art example, the backlash with the pulley tooth groove portion 3xe2x80x2 is reduced to zero at the tooth root portion 12xe2x80x2 of the belt tooth portion 11xe2x80x2, while the backlash with the pulley tooth groove portion 3xe2x80x2 is gradually increased from the tooth root portion to the tooth tip portion of the belt tooth portion 11xe2x80x2 so that the belt tooth portion 11xe2x80x2 tapers toward the tooth tip portion, thereby to suppress meshing interference between the belt tooth portion 11xe2x80x2 and the tooth top arc portion 4xe2x80x2 of the pulley tooth groove portion 3xe2x80x2 for the reduction of belt pitch line variation due to such meshing interference. In FIG. 17, tooth groove flank surface portions of concave profile of the pulley tooth groove portion 3xe2x80x2 are assigned the reference numeral 5xe2x80x2, a tooth groove bottom portion is assigned the reference numeral 6xe2x80x2, and the pitch line of the belt 8xe2x80x2 is denoted by PL, which corresponds to the pitch circle of the pulley 1xe2x80x2. Further, for the purpose of providing an easy understanding, in FIG. 17 the outer peripheral portion of the pulley 1xe2x80x2 is shown in expanded fashion, together with the belt 8xe2x80x2.
Apart from the above, in a typical business machine such as a printer and photocopier, a character printing (including printing of images) device making utilization of a toothed belt power transmission apparatus is used widely. In such a printer, a carriage carrying thereon an ink supply and a printing mechanism such as a hammer is attached to a toothed belt. The toothed belt is wound around toothed pulleys and the pulleys are forwarded and reversed to cause the carriage to reciprocate.
In order to enable the carriage to provide improved printing accuracy and image quality, it is required that the nonuniformity of velocity of the toothed belt when traveling over the pulleys (i.e., the belt velocity variation) be reduced as low as possible. Particularly, for the case of printers, there have been made rapid improvements in color printing, color printing speed-up, color printing quality. The meshing vibration (velocity nonuniformity caused by meshing) of toothed belt may cause printing nonuniformity and image nonuniformity, so that there have been strong demands for the reduction of the nonuniformity of belt velocity caused by meshing.
For the case of equipment for business use such as a printer, a toothed belt, such as an STPD toothed belt or HTD-II toothed belt, is commonly used, wherein the tooth pitch is set below 3 mm (for example, either 3 mm, 2 mm, or 1.5 mm), and the tooth has a profile which is just a scaledown of the tooth profile of relatively large tooth pitch such as 8-mm pitch or 5-mm pitch.
However, these tooth profiles were originally developed for use in high power transmission, in which no scheme to meet demands for the reduction of the nonuniformity of velocity was taken into consideration at all. Although the toothed belt of the foregoing prior art (S64-74341) was proposed taking into account the occurrence of belt velocity nonuniformity to some extent, it failed to provide a tooth profile optimum for the reduction of the nonuniformity of velocity. This prior art technique is therefore unable to reduce the nonuniformity of belt velocity to a sufficient extent.
In fact, little research in tooth profile has been done for the reduction of toothed belt velocity nonuniformity. Bearing in mind the above, the present invention was made by the inventor who intensively conducted analysis and experiments on various factors constituting a tooth profile of a toothed belt for use in equipment for business use or the like. Accordingly, an object of the present invention is to reduce the nonuniformity of toothed belt velocity as low as possible.
In order to achieve the above-described object, the inventor conducted research. The research result had shown that, for the case of toothed belts having tooth portions with convex flank surface portions, the flank maximum pressure angle had considerable influence on the nonuniformity of velocity. This factor had not at all been taken into consideration before. That is to say, in conventional toothed belts having either an STPD tooth profile or an HTD-II tooth profile for use in high power transmission applications, the maximum pressure angle of the tooth flank surface is set low for the avoidance of tooth jumping occurring during high power transmission operation. For example, for an STPD tooth profile whose tooth pitch is between 1.5 mm and 3.0 mm, the flank maximum pressure angle is set to fall in the range between an angle of 14.2 degrees and an angle of 14.4 degrees, while, for an HTD-II tooth profile whose tooth pitch between 1.5 mm and 3.0 mm, the flank maximum pressure angle is set to fall in the range between an angle of 7.5 degrees and an angle of 8.1 degrees. On the other hand, for the case of toothed belts that find applications in equipment for business use, they are driven under low power transmission conditions. Therefore, there is almost no need to take into account belt tooth jumping. The research result by the inventor shows that the nonuniformity of belt velocity can be reduced to a considerable extent if the flank maximum pressure angle is set to fall in the range between an angle of 15 degrees and an angle of 25 degrees.
As an embodiment of the above finding, the present invention provides a toothed belt which comprises a belt main body with a pitch line on which a tensile member is embedded therein and a plurality of belt tooth portions provided at a fixed pitch on a land line of the belt main body. Each of the belt tooth portions comprises tooth root portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth width direction, power transmission portions formed of circularly arcuate surfaces of convex profile which contiguously adjoin the tooth root portions, lie at flank surfaces of the tooth portion, and are arranged symmetrically with each other in respect to the tooth width direction centerline, tooth tip portions formed of circularly arcuate surfaces which contiguously adjoin the power transmission portions and are arranged symmetrically with each other in respect to the tooth width direction centerline, and a tooth crest surface formed of an approximately flat surface which interconnects the tooth tip portions, wherein the maximum pressure angle at where the power transmission portion of the belt tooth flank surface and the tooth root portion are connected together is between an angle of 15 degrees and an angle of 25 degrees.
At the time when a tooth portion of the toothed belt comes into meshing engagement with a driving-side tooth groove portion of the toothed pulley, such engagement of the belt tooth portion with the pulley tooth groove portion takes place at a location which is somewhat delayed with respect to the location of the pulley tooth groove portion because of the influence of load torque that is applied. Consequently, an aft flank surface of the belt tooth portion in respect to the traveling direction is first brought into contact with a flank surface of the pulley tooth groove portion. Thereafter, the belt tooth portion slides into the pulley tooth groove portion. At this time, at a span of the belt (i.e., at a belt portion that is not being wound around the pulley), the belt pitch line moves vertically in a direction normal to the belt span, resulting in the occurrence of meshing velocity nonuniformity. The amount of vertical movement of the belt pitch line is determined by a reaction force produced when the belt tooth portion slides into the pulley tooth groove portion and a component of a belt tension force produced when the belt is pushed upward by the reaction force. Because of this, as the contact position moves away from the perfect meshing position of the belt tooth portion and the pulley tooth groove portion, the belt tension force component decreases, thereby increasing the amount of upward movement of the belt pitch line. In other words, earlier contacting of the belt tooth portion with the pulley tooth groove portion results in greater velocity nonuniformity. Therefore, if the maximum pressure angle is small as in the conventional tooth profiles, then the contacting of the belt tooth flank surface with the pulley tooth groove flank surface takes place early (see FIG. 4(b)). On the other hand, if the maximum pressure angle is set larger in comparison with the conventional techniques, this delays the contacting of the belt tooth flank surface with the pulley tooth groove flank surface (see FIG. 4(a)), thereby reducing the nonuniformity of belt velocity.
However, the maximum pressure angle cannot be increased excessively and if the maximum pressure angle is too great, this will not reduce the nonuniformity of velocity; rather the nonuniformity of velocity increases. That is to say, as described above, the amount of shift of the belt span is determined by reaction force (produced when the belt tooth portion slides into the pulley tooth groove portion after their flank surfaces come into contact with each other) and belt tension force component. However, at that time, if the maximum pressure angle is too great, then a component of a reaction force in the vertical direction (i.e., in the direction normal to the belt span) produced when the belt tooth portion slides into the pulley tooth groove portion becomes too great. This will not allow the belt tooth portion to smoothly slide into the pulley tooth groove portion, therefore pushing up the belt pitch line to increase the nonuniformity of velocity.
The analysis result obtained by the inventor shows that an optimal allowable range for the maximum pressure angle is between an angle of 15 degrees and an angle of 25 degrees as described above. In comparison with the commonly-used pressure angle range (between an angle of 14.2 degrees and an angle of 14.4), the present invention is able to reduce the nonuniformity of velocity more effectively.
Further, the maximum pressure angle at where the power transmission portion of the belt tooth flank surface and the tooth root portion are connected together is between an angle of 16 degrees and an angle of 23 degrees. Furthermore, the maximum pressure angle is between an angle of 17 degrees and an angle of 22 degrees. As a result of such arrangement, the nonuniformity of velocity can be reduced to a further extent.
The present invention provides a toothed belt comprising a belt main body with a pitch line on which a tensile member is embedded therein and a plurality of belt tooth portions provided at a fixed pitch on a land line of the belt main body. Each of the belt tooth portions comprises tooth root portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth width direction, power transmission portions formed of circularly arcuate surfaces of convex profile which contiguously adjoin the tooth root portions, lie at flank surfaces of the tooth portion, and are arranged symmetrically with each other in respect to the tooth width direction centerline, and a tooth tip end portion formed of a circularly arcuate surface which is so provided as to interconnect the power transmission portions and whose center point lies on the tooth width direction centerline, wherein the maximum pressure angle at where the power transmission portion of the belt tooth flank surface and the tooth root portion are connected together is between an angle of 15 degrees and an angle of 25 degrees.
Such a tooth construction is able to provide the same effects as above. Further, since the tooth tip end portion of the belt tooth portion is defined by a single circularly arcuate surface, this makes it possible to further delay the contacting of the belt tooth portion with the pulley tooth groove portion in comparison with increasing only the maximum pressure angle (see the virtual line of FIG. 8). Accordingly, the nonuniformity of belt velocity can be reduced to a further extent.
In such a case, the maximum pressure angle in the toothed belt is between an angle of 16 degrees and an angle of 23 degrees. Further, the maximum pressure angle is between an angle of 17 degrees and an angle of 22 degrees. As a result of such setting, the nonuniformity of velocity of the toothed belt can be reduced to a further extent.
The present invention provides a toothed belt power transmission apparatus comprising a combination of any one of the preceding toothed belts and toothed pulleys each having a plurality of pulley tooth groove portions which are provided at a fixed pitch on a pulley outside diameter line. Each of the pulley tooth groove portions comprises tooth top arc portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth groove width direction, tooth groove flank surface portions formed of circularly arcuate surfaces of concave profile which contiguously adjoin the tooth top arc portions and are arranged symmetrically with each other in respect to the tooth groove width direction centerline, and a tooth groove bottom portion provided so as to interconnect the tooth groove flank surface portions. The belt tooth portion has flank surfaces whose profile is substantially the same as that of flank surfaces of the pulley tooth groove portion. Further, in a power transmission state (i.e., in a working state) in which the toothed belt is wound around the toothed pulleys and a tension force is applied to the toothed belt, the pressure angles of the belt tooth portion flank surface and the pulley tooth groove portion flank surface at their respective locations in the tooth height direction are made approximately equal to each other and a belt land portion comes into contact with a pulley outside diameter portion.
As described above, if the maximum pressure angle is so increased as to fall within the range below 25 degrees (preferably, between an angle of 17 degrees and an angle of 22 degrees), this delays the belt tooth flank surface to come into contact with the pulley tooth groove flank surface, resulting in reducing the nonuniformity of belt velocity. Other than this, even when the pressure angle of the belt tooth portion remains small as in the conventional techniques, it is possible to geometrically delay, within the delay range of the pulley tooth groove portion with respect to the belt tooth portion during low power torque transmission, the contacting of the belt tooth flank surface with the pulley tooth groove flank surface by setting the maximum pressure angle of the pulley tooth groove portion smaller than that of the belt tooth portion. As described above, if the maximum pressure angle of the pulley tooth groove portion is made smaller than that of the belt tooth portion, then the backlash between the belt tooth portion and the pulley tooth groove portion~gradually increases from root to tip. This is the same construction as shown in the prior art technique (JP Unexamined Patent Application Gazette No. S64-74341).
However, the inventor""s research shows that if the maximum pressure angle of the pulley tooth groove portion is set smaller than the maximum pressure angle of the belt tooth portion, this increases the nonuniformity of velocity of the belt. That is to say, when the maximum pressure angle of the pulley tooth groove portion is set smaller than the maximum pressure angle of the belt tooth portion, this certainly delays the contacting of the belt tooth flank surface with the pulley tooth groove flank surface; however, the belt tooth flank surface is brought into contact, not with the pulley tooth groove flank surface but with the tooth top arc portion (see FIG. 5(b)). As a consequence of such contact, the belt tooth portion is pushed up by the tooth top arc portion of the pulley tooth groove-portion, so that the belt tooth portion is unable to smoothly slide into the pulley tooth groove portion and the belt pitch line is pushed up, resulting in increasing the nonuniformity of velocity.
On the other hand, according to the toothed belt power transmission apparatus of the present invention, it is arranged such that the pressure angles of the belt tooth portion flank surface and the pulley tooth groove portion flank surface at their respective locations in the tooth height direction are made approximately equal to each other, so that the belt tooth flank surface comes into uniform contact with the pulley tooth groove flank surface. This allows the belt tooth portion to smoothly slide into the pulley tooth groove portion (see FIG. 5(a)). The belt pitch line will not be pushed up, which considerably reduces the nonuniformity of velocity of the belt.
Further, an arrangement may be made, in which the pulley tooth groove portion of the toothed pulley has a tooth groove bottom portion which is formed of an approximately flat surface. As a result of such arrangement, the tooth groove bottom portion of the pulley tooth groove portion and the tooth crest surface of the belt tooth portion are formed of identical, approximately flat surfaces, which is preferable. The tooth groove bottom portion may be formed of a surface inscribing an arc of a circle having its center in the pulley central direction.
The present invention provides a toothed belt power transmission apparatus comprising a combination of the foregoing toothed belt and toothed pulleys each having a plurality of pulley tooth groove portions which are provided at a fixed pitch on a pulley outside diameter line. Each of the pulley tooth groove portions comprises tooth top arc portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth groove width direction, tooth groove flank surface portions formed of circularly arcuate surfaces of concave profile which contiguously adjoin the tooth top arc portions and are arranged symmetrically with each other in respect to the tooth groove width direction centerline, and a tooth groove bottom portion provided so as to interconnect the tooth groove flank surface portions, wherein the belt tooth portion has flank surfaces whose profile is substantially the same as that of flank surfaces of the pulley tooth groove portion and wherein in a power transmission state in which the toothed belt is wound around the toothed pulleys and a tension force is applied to the toothed belt, the pressure angles of the belt tooth portion flank surface and the pulley tooth groove portion flank surface at their respective locations in the tooth height direction are made approximately equal to each other and a belt land portion comes into contact with a pulley outside diameter portion. This construction is also able to provide the same operation and effects as the above.
Furthermore, in the foregoing toothed belt power transmission apparatus of the present invention, the pulley tooth groove portion of each of the toothed pulleys has a tooth groove bottom portion which comprises a circularly arcuate surface inscribing an arc of a circle whose center point lies on the tooth groove width direction centerline and whose radius is greater than that of the tooth tip end portion of the belt tooth portion. That is to say, in the case the belt tooth portion has a tooth tip end portion which is a circularly arcuate surface (i.e., a curvilinear surface inscribing the arc of a circle), the pulley tooth groove portion may have a tooth groove bottom portion which is an approximately flat surface. In the present invention, however, the tooth groove bottom portion of the pulley tooth groove portion is formed of a circularly arcuate surface whose radius is greater than that of the tooth tip end portion of the belt tooth portion. This arrangement is preferable because the belt tooth portion is able to slide into the pulley tooth groove portion in a much smoother manner.
The present invention provides a toothed belt power transmission apparatus comprising a combination of a toothed belt and toothed pulleys. The toothed belt has a belt main body with a pitch line on which a tensile member is embedded therein, a plurality of belt tooth portions provided at a fixed pitch in the belt main body, and a land portion provided between adjacent belt tooth portions. Each of the belt tooth portions has power transmission portions formed of circularly arcuate surfaces of convex profile which lie at flank surfaces of the tooth portion and are arranged symmetrically with each other in respect to a centerline in the tooth width direction, tooth tip portions formed of circularly arcuate surfaces which contiguously adjoin the power transmission portions and are arranged symmetrically with each other in respect to the tooth width direction centerline, and a tooth crest surface formed of an approximately flat surface which is so provided as to interconnect the tooth tip portions. On the other hand, each of the toothed pulleys has a plurality of pulley tooth groove portions provided at a fixed pitch on a pulley outside diameter line. Each of the pulley tooth groove portions has tooth top arc portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth groove width direction, tooth groove flank surface portions formed of circularly arcuate surfaces of concave profile which contiguously adjoin the tooth top arc portions and are arranged symmetrically with each other in respect to the tooth groove width direction centerline, and a tooth groove bottom portion provided so as to interconnect the tooth groove flank surface portions. The maximum pressure angle at where the tooth top arc portion and the tooth groove flank surface portion in the pulley tooth groove portion are connected together is between an angle of 15 degrees and an angle of 25 degrees and the belt tooth portion has flank surfaces whose profile is substantially the same as that of flank surfaces of the pulley tooth groove portion. Moreover, in a power transmission state in which the toothed belt is wound around the toothed pulleys and a tension force is applied to the toothed belt, the pressure angles of the belt tooth portion flank surface and the pulley tooth groove portion flank surface at their respective locations in the tooth height direction are made approximately equal to each other and a belt land portion does not come into contact with a pulley outside diameter portion.
The arrangement for reducing the nonuniformity of belt velocity by increasing the maximum pressure angle is effective for toothed belt power transmission apparatus that are used in such a condition that the belt land portion does not come into contact with a pulley outside diameter portion. However, in such a case, areas of the belt land portion, the tooth root portion of the tooth portion, and the tooth flank surface that lie outside beyond the pulley outside diameter portion in the radial direction have no direct influence on the behaviors of the belt tooth portion at the time of meshing. Accordingly, the maximum pressure angle of the belt tooth portion in the belt alone is not important, but the maximum pressure angle at a connection point of the tooth top arc portion and the tooth groove flank surface portion is important. In accordance with the present invention, the maximum pressure angle at where the tooth top arc portion and the tooth groove flank surface portion are connected together is between an angle of 15 degrees and an angle of 25 degrees, as a result of which arrangement the same operation and effects as the above can be obtained.
In the above-described toothed belt power transmission apparatus, the land portion of the toothed belt comprises an approximately flat surfaces which is interconnected with the belt tooth portion flank surfaces through tooth root portions formed of circularly arcuate surfaces which are arranged symmetrically with the tooth width direction centerline.
The land portion of the belt, since there is no constraint when taking into account the nonuniformity of belt velocity, may be formed of a circularly arcuate surface; however, it is preferable that the belt land portion be formed of an approximately flat surface. That is to say, toothed belts made of polyurethane have been used widely in equipment for business use because they are superior in the shape accuracy of tooth portions or the like. Particularly, when the belt tooth portion pitch is below 1.5 mm, nearly all of toothed belts are made of polyurethane, for rubber belts are not able to meet requirements of the business equipment because they are poor in tooth shape accuracy. In such a polyurethane toothed belt, a concave portion is practically provided in the belt land portion in order to separate the core cord from the land line. However, when the belt tooth portion pitch is below 1.5 mm, the formation dimensions of such a concave portion are considerably small, resulting in difficult die processing. In order to cope with such a problem, the core cord is provided directly over the land line without the provision of the foregoing concave portion, and the belt is used in such a condition that the belt land portion is not brought into contact with a pulley outside diameter portion so as to prevent the core cord from being damaged by contact with the pulley outside diameter portion. In such a case, since in the present invention the belt land portion is an approximately flat surface, the position of the core cord can be made stable by the belt land portion which is approximately flat.
In such a case, the maximum pressure angle at where the tooth top arc portion and the tooth groove flank surface portion in the pulley tooth groove portion of the toothed belt power transmission apparatus are connected together is between an angle of 16 degrees and an angle of 23 degrees. Further, the maximum pressure angle is between an angle of 17 degrees and an angle of 22 degrees. As a result of such arrangement, the nonuniformity of toothed belt velocity can be reduced to a further extent.
Further, in the present invention, the pulley tooth groove portion of the toothed pulley has a tooth groove bottom portion which is formed of an approximately flat surface. As a result of such arrangement, when the belt is wound around the pulley, the toot tip end portion of the belt tooth portion can be received at the tooth groove bottom portion of the pulley tooth groove portion whose area is large. This makes it possible to stabilize the core cord position (pitch line) of the belt when wound around the pulley. This reduces the nonuniformity of velocity to a further extent.
The present invention provides a toothed belt power transmission apparatus comprising a combination of a toothed belt and toothed pulleys. The toothed belt has a belt main body with a pitch line on which a tensile member is embedded therein, a plurality of belt tooth portions provided at a fixed pitch in the belt main body, and a land portion provided between adjacent belt tooth portions. Each of the belt tooth portions has power transmission portions formed of circularly arcuate surfaces of convex profile which lie at flank surfaces of the tooth portion and are arranged symmetrically with each other in respect to a centerline in the tooth width direction and a tooth tip end portion formed of a circularly arcuate surface which is so provided as to interconnect the power transmission portions and whose center point lies on the tooth width direction centerline. On the other hand, each of the toothed pulleys has a plurality of pulley tooth groove portions provided at a fixed pitch on a pulley outside diameter line. Each of the pulley tooth groove portions has tooth top arc portions formed of circularly arcuate surfaces which are arranged symmetrically with each other in respect to a centerline in the tooth groove width direction, tooth groove flank surface portions formed of circularly arcuate surfaces of concave profile which contiguously adjoin the tooth top arc portions and are arranged symmetrically with each other in respect to the tooth groove width direction centerline, and a tooth groove bottom portion provided so as to interconnect the tooth groove flank surface portions. The maximum pressure angle at where the tooth top arc portion and the tooth groove flank surface portion in the pulley tooth groove portion are connected together is between an angle of 15 degrees and an angle of 25 degrees. The belt tooth portion has flank surfaces whose profile is substantially the same as that of flank surfaces of the pulley tooth groove portion. In a power transmission state in which the toothed belt is wound around the toothed pulleys and a tension force is applied to the toothed belt, the pressure angles of the belt tooth portion flank surface and the pulley tooth groove portion flank surface at their respective locations in the tooth height direction are made approximately equal to each other and a belt land portion does not come into contact with a pulley outside diameter portion.
That is to say, in accordance with the toothed belt power transmission apparatus of the present invention, the construction of the belt tooth portion is changed to the same one as the above and the same operation and effects as the above can be obtained.
In such a case, the land portion of the toothed belt in the toothed belt power transmission apparatus comprises an approximately flat surface which is interconnected with the belt tooth portion flank surfaces through tooth root portions formed of circularly arcuate surfaces which are arranged symmetrically with the tooth width direction centerline. Such arrangement provides the same effects as the above.
Further, in accordance with the toothed belt power transmission apparatus of the present invention, the maximum pressure angle at where the tooth top arc portion and the tooth groove flank surface portion in the pulley tooth groove portion are connected together is between an angle of 16 degrees and an angle of 23 degrees. Moreover, the maximum pressure angle is between an angle of 17 degrees and an angle of 22 degrees. As a result of such arrangement, the nonuniformity of toothed belt velocity can be reduced to a further extent.
In accordance with the toothed belt power transmission apparatus, the pulley tooth groove portion of the toothed pulley has a tooth groove bottom portion which comprises a circularly arcuate surface inscribing an arc of a circle whose center point lies on the tooth groove width direction centerline and whose radius is greater than that of the tooth tip end portion of the belt tooth portion. Such arrangement provides the same effects as the above.
Finally, the present invention provides equipment for use in business applications which is provided with a toothed belt power transmission apparatus formed in accordance with the present invention wherein a carriage is attached to the toothed belt. As a result of such arrangement, during the operating time of the toothed belt power transmission apparatus, when the carriage is shifted for performing character printing, the variation in carriage velocity caused by the nonuniformity of belt velocity is reduced. This makes it possible for the carriage to provide improved printing accuracy and image quality.

Toothed belt, toothed belt power transmission apparatus, and business equipment employing the same


A method for capturing CO2 from a CO2 containing gas (1), such as en exhaust gas from a thermal power plant fired on carbonaceous fuel, or any other CO2 containing industrial gas, where CO2 is captured from the gas by causing the gas to flow counter current to a CO2 absorbing solvent introduced into a CO2 absorption section (3) in an absorber (2) so that CO2 present in the gas is absorbed by the CO2 absorbing solvent to form a CO2 rich solvent (5), where CO2 rich solvent is collected on the bottom of the of the absorption column and withdrawn for regeneration, and where the treated exhaust gas (8) is released to the atmosphere after being subjected to one or more washing step(s) (6,7), wherein the temperature of the CO2 absorbing solvent (4) introduced into the CO2 absorption section has a temperature that is less than 5° C. lower than the maximum temperature in the absorption section of the absorber, is described.

A typical absorber for CO2 is a tower where exhaust gas from which CO2 is to be absorbed/removed, is brought in counter current contact with an aqueous CO2 absorbent, such as an amine, in a contact zone. The contact zone normally comprises a CO2 absorption section to increase the contact surface between the absorbent and the gas.
Absorbent having absorbed CO2 is collected below the contact zone, and exhaust gas reduced in CO2 content is released from the top of the absorber.
An amine based CO2 absorber is normally equipped with one or more water wash section(s) above the CO2-absorbing contact zone. The main objective of the water wash is to absorb amine vapour in order to minimise emission of amine to air. Another objective is to cool the gas and condense water in order to fulfil the requirement for water balance across the entire absorber. The condensation of water from the flue gas is a source for wash water makeup. Excess water in the water wash system is bled off and routed to the amine section below, and the effect of these make-up and bleed streams is reduced amine content in the water wash liquid.
One normally assumes close approach to equilibrium in the top of the water wash packed section with liquid recycling, meaning the gas will contain an amine partial pressure equivalent to the liquid amine vapour pressure, which again is dictated by the liquid temperature, amine concentration, CO2 loading and pH. Hence a water wash operating at low temperature with high liquid replacement rate is preferred in order to minimise the amine slip to atmosphere, since lower temperature and lower amine concentration decreases amine vapour pressures.
EP 0502596 A (MITSUBISHI JUKOGYO KABUSHIKI) 09.09.1992 relates to an absorber for a CO2 capture plant where the CO2 lean exhaust gas is washed and cooled, and the temperature of the gas leaving the absorber is substantially equal to the gas introduced into the absorber. The washing is done to reduce amine emission. The temperature is controlled to avoid loss or building up of water in the plant.
US 2003045756 A (MIMURA TOMIO) 06.03.2003 relates to an absorber in a CO2 capture plant wherein demisters are provided between absorption and washing sections and between washing sections to reduce amine emission. Additionally, amine vapour is removed from the gas by washing and cooling the gas.
Extensive emission measurements have been performed by the applicant on an operating pilot, treating flue gas from a coal fired boiler. Various CO2 absorbing solvents have been tested, including 30wt % MEA. The pilot contains two water wash sections, where the upper section can be utilised as an acid wash in dedicated campaigns. An acid wash, as described in EP 2335802 A (MITUBISHI HEAVY INDUSTRIES, LTD.) 22.06.2011 and WO 2010/102877 A (AKER CLEAN CARBON AS) 16.09.2010 has proven effective at capturing gaseous phase alkaline compounds. FIG. 1 (Prior art) illustrates a simplified scheme of the pilot. Both online analysis (FTIR) and offline sampling of gas have been conducted.
There has surprisingly, under certain periods, been detected high emission of amine, even with operation of the acid wash in the absorber top that eliminates emission of ammonia and volatile alkyl amines. The amine emission could not be explained by the water wash vapour-liquid equilibrium assumption. It is discovered that this emission is in the form of mist, and that the more hydrophilic compounds such as MEA tends to be highly accumulated in the mist. The FTIR gas analyser samples and evaporates the mist in the heated sampling line (working at 180° C.), and hence measures the total amine content as vapour. It has been discovered that the mist precursors are ultrafine solids particles of fly ash, soot or salts in the flue gas entering the absorber.
Another test was performed at a smaller scale pilot, where the flue gas source is a propane burner. During normal operation, the emission from the pilot was not detectable by the FTIR. The burner was then manipulated to burn with excess fuel, resulting in high CO and soot formation. High amine emission and visible mist plume was observed, indicating soot particles acting as mist nucleation seeds.
These fine particles are initially acting as nucleates for water condensation in regions inside the absorber where water saturated gas is rapidly cooled. When formed, these mist droplets absorb amine from the surrounding gas phase. Emission measurements during campaigns with amine solvents such as MEA have proven that, in the absorber system with two water wash sections, the mist borne emission is the main contributor to overall amine emission. On the other hand, the emission of ammonia (which is a degradation product of amines such as MEA) is not related to the mist emission. This is ascribed the limited solubility of ammonia and hence limited accumulation in the mist droplets.
Mist with small droplet size, when formed, is very difficult to remove in wet scrubbers and conventional demisters. The mist droplets are in the size range of 0.1-10 μm diameter, and the mist forms a visible white plume from the top of the pilot absorber.
Mist elimination by fibre type demisters is known from other industries. The superficial velocity through such demisters has to be very low and the pressure drop is high, making this type of demisters less attractable for large gas volume applications like power plant flue gas cleaning. Wet electrostatic precipitator (ESP) is also proven efficient for removing mist and fine dust, but has high investment and operating cost.
The applicant has experienced that formation of mist may also be reduced by removing or reducing the content of fine and ultrafine particles from the incoming gas before introduction of exhaust gas into the CO2 absorber. Conventional processes for removal of fine and superfine particles, such as ESP and wet flue gas desulphurization (FGD) have limited efficiency in capturing particles in the sub-micron range. As for removal or reduction of mist, wet ESP may be used to reduce or remove the sub-micron particles. As mentioned above, the investment and operating cost for wet ESP are high.
The solutions according to prior art is that they are not efficient in reducing mist following the gas that is washed.
The problem to be solved by the present invention is to eliminate or substantially reduce the release of amines or degradation products thereof from an amine based carbon capture plant. More specifically, the invention is directed to reduction of the release of amines caused by formation of mist that is released to the surroundings together with the CO2 lean exhaust gas.
Accordingly, alternative solutions allowing reduction of the emission of mist, or droplets, and most specifically mist containing high concentration of amines or degradation products thereof, from the absorber of an amine based plant for CO2 capture is therefore sought.


A technique for permitting tracepoints to be set relative to data components of object oriented programs for debugging purposes is disclosed. A new method is created or an existing method is modified in an object which contains data relative to which tracing is desired. The new or modified method intercepts a message intended to access the designated data, and depending on the type of access being attempted and/or other conditions set by the developer, tracing may be initiated, modified, or terminated. Tracing is controlled by forwarding an appropriate message to a trace manager. The read or write operation is preserved by the newly created access method, which performs the desired access of the data component.

1. Field of the Invention
The present invention relates to a technique for debugging object oriented software applications. More particularly, the present invention provides a data triggered trace support in a debugger for debugging object oriented software programs.
2. Description of the Related Art
One critical and often overlooked component in the process of developing software programs is the elimination of errors from the software programs. The process of eliminating errors is known as debugging. After one or more software developers writes the code for a software program and the code files are built to produce an executable version of the software program, the software program must be tested to determine what errors exists in the program, and then the program must be debugged to reduce or eliminate the errors. For commercial software, it is imperative that most of the errors or bugs are found and eliminated prior to the software being released to the marketplace. The debugging process can be quite extensive, costly and time consuming. Accordingly, software tools and techniques have been developed to assist in the debugging of code and reduce the debugging cycle time.
For errors or bugs found in commercial software applications that have already been released, time is critical. Software manufactures must have tools to respond to customer complaints about bugs rapidly and provide fixes and/or debugged software quickly. Software errors or bugs can be categorized into two types. The first type is a logic error, in which logic statements or commands included by the software developer in the program are flawed, such that the desired function is not performed during execution of the program, or is not performed properly, etc. Typically, logic errors cause the program to execute functions or commands within the program which are not desired by the developer. The second type of error is with regard to data being maintained or used by the program, and occurs when the data is somehow corrupted.
A number of debugging functions and techniques are presently employed in currently available debugging software tools. One set of known techniques are referred to as testpoints, and include the setting of breakpoints, tracepoints, watchpoints, etc. However, the use of tracepoints is somewhat limited. While tools exist to set tracepoints so as to trigger a creation of trace information upon the execution of a specific logic unit in a program being debugged, no similar mechanism exists for setting tracepoints so as to trigger tracing relative to specific data elements or entities, such as instance variables in Smalltalk language programs, within or utilized by a program being debugged. The existing logic based trace function can create information regarding data movement, but only in the context of data movement that occurs upon the execution of a logic unit, such as a Smalltalk method. Further, information is created relative to all data components affected by execution of the logic unit. Where the information is being sought relative to a single data entity, the logic-based tracepoint procedure is costly in terms of processing time, since information relative to all affected data components is gathered, and in terms of developer time, as the developer must sort through information relevant to all affected data components to find information pertaining to the desired one. The ability to trigger the generation of trace data based upon a specific data component so that information can be obtained relative to the data component during execution of logic units would be a valuable tool for developers in the debugging of programs.
Recently, a revolution of sorts has been occurring in the software industry. Until recently, most software programs have been written in procedural languages, such as C and COBOL. Accordingly, debugging tools and techniques were designed to debug procedural programs. The advent of object oriented languages has created a paradigm shift. Object oriented languages are fundamentally different in the way they are written by developers and executed by a computer at runtime. In the two leading object oriented languages, C++ and Smalltalk, data is actually stored within the objects in object oriented programs written in these languages. In Smalltalk, data is stored in the instance variables of Smalltalk objects and the class variables or class instance variables of Smalltalk classes, and in C++, data is stored in the variables of the C++ objects. Thus, object oriented programs present new challenges for debugging tools.
U.S. Pat. No. 5,093,914, which issued to Coplien et al., discloses a method for using breakpoints in the debugging of object oriented programs. This patent is of interest because a breakpoint is one type of test point. However, the Coplien patent does not address tracepoints, and does not address the problem of or provide a solution for the lack of a trace function relative to data components of an object oriented program.
IBM's cross system product (CSP), version 4.1, which was released in 1992, provides an object oriented solution for the debugging of procedural programs. However, while that product provides for the use of tracepoints relative to logic units, it does not enable the setting of tracepoints relative to data components in a procedural program.
Accordingly, a need exists for a debugging tool which permits a developer to set tracepoints for specific data components within an object oriented program under going debugging in order to gather trace information specific to the designated data components.

Data triggered trace support for debugging object oriented programs


An Li--Mn ferrite carrier comprising 2 to 15 mol % of Li.sub.2 O, 5 to 30 mol % of MnO and 60 to 90 mol % of Fe.sub.2 O.sub.3. The carrier may contain at least one sintering aid selected from the group consisting of CaO, Na.sub.2 O, SiO.sub.2, V.sub.2 O.sub.5, Al.sub.2 O.sub.3, As.sub.2 O.sub.3, Bi.sub.2 O.sub.3, Sb.sub.2 O.sub.3 and B.sub.2 O.sub.3 to improve the surface properties thereof. The carrier may be made sensitive to the intensity of electric field by regulating the specific volume resistivities at 200 V/cm and 10 kV/cm within the specific ranges. This carrier is particularly suitable in the reversal developing method, and in the developing method where an A.C. bias voltage is superimposed to a D.C. bias voltage.

The present invention relates to a magnetic carrier made of Li--Mn ferrite for use in a two-component developer which is used for developing electrostatic latent images formed on a surface of an image-bearing member (photosensitive drum) of image-forming apparatus such as laser beam printers, dry copying machines, etc. The present invention further relates to a two-component developer containing the Li--Mn ferrite carrier. The present invention still further relates to a method of developing electrostatic latent images by using a two-component developer containing the Li--Mn ferrite carrier.
In electrophotographic recording apparatus, it is known that a visual toner image is produced by the successive steps, for example, of (1) forming an electrostatic latent image corresponding to original image or information data, for instance, on a photosensitive surface of a cylindrical photosensitive drum (image-bearing member), (2) magnetically attracting a magnetic developer on a rotating developing roll equipped with an inner permanent magnet and disposed opposing the photosensitive drum, (3) delivering the magnetic developer, while forming a magnetic brush, to a developing zone where the electrostatic latent image on the photoconductive drum is slidingly brushed with the magnetic brush to produce toner images. The developed image is then transferred to a recording sheet and fixed thereon by heating or applying pressure
As the developer, one-component developer containing only a toner or two-component which is a mixture of a toner and a magnetic carrier has been used. In the two-component developer development, when the toner and the magnetic carrier are mixed together in a predetermined mixing ratio, the toner and the magnetic carrier acquire triboelectric charges of opposite polarities to allow the toner to cling to the magnetic carrier by electrostatic attraction. The magnetic carrier electrostatically retaining the toner is then supplied on the surface of a developing roller to form rotating magnetic brushes. The photoconductive surface containing the latent images is brought into brushing contact with the rotating magnetic brushes. During the brushing contact, only the toner is deposited on the image areas by electrostatic attraction between the latent image and the toner to produce visual toner images.
Generally, the two-component developer is required to have a good stability in image quality and to maintain such a stability against a continuous developing operation. To attain this long stability, it is necessary to regulate the ability of the carrier to providing the toner with triboelectric charges and the electric resistance of the developer within a suitable level. In addition, it is desirable that the ability and the electric resistance are not changed even in a long developing operation.
The toner is usually produced by blending a binder resin with several additives such as a colorant including dyestuff and pigment, a magnetic powder, a charge controlling agent, a wax, etc. to disperse the additives in the binder resin. To make the electric resistance of the developer stable, it has been considered to select suitable binder resin, charge controlling agent and other additives. As the material for the carrier, iron powder and a ferrite powder have been mainly used. To ensure a stable ability of providing the toner with a suitable amount of triboelectric charges, several considerations have been made in oxidation treatment of iron powder, material for the ferrite powder, the surface property of the powder, materiel for a coating, a method of coating, etc.
The iron carrier is usually produced by subjecting to its surface a suitable treatment such as oxidation treatment. The iron carrier subjected to such a treatment physically or chemically changes its surface conditions in a developing operation of a long period of time to make the toner cling thereon, thereby causing several defects of a decreasing ability of providing the toner with a sufficient triboelectric charges, a reduction in the resolution of produced images due to a high susceptibility to a moisture of the environment, and a short durability.
The ferrite carrier has become to be used in place of the iron carrier because it is chemically more stable than the iron carrier, it less changes its electric resistance during the use and its apparent density is about 2/3 of that of the iron carrier.
The ferrite carrier is a sintered product of a complete mixture of an iron (III) oxide and an oxide of at least one element such as Ni, Zn, Mn, Mg, Cu, Li, Ba, V, Cr, Ca, etc., and the practically used may include an Ni--Zn ferrite, an Mn--Zn ferrite and a Cu--Zn ferrite.
However, Zn, Ni, etc. are noxious to human body and the disposal of waste ferrite carrier containing such elements is legislatively regulated. The Li--Mn ferrite is not needed to be legislatively regulated, and therefore, such an advantage of the Li--Mn ferrite carrier is recently noted in the art. However, since the optimal chemical composition and the optimal developing conditions have not yet been established, it is difficult at present to stably reproduce images of a high quality by the use of a developer containing the Li--Mn carrier in a continuous developing operation.
In laser beam printers, digital copying machines, etc. which are coming to be widely used, a reversal developing method is usually employed, in which the latent image is formed by exposing a uniformly charged photoconductive surface to lights to discharge the image areas and remain nonimage areas charged. In the reversal developing method, a toner charged to the same polarity as that of the photoconductive surface is deposited on the latent image having a potential of about zero volt. Therefore, a high bias voltage is required to be applied between the developing roll and the photoconductive surface to sufficiently deposit the toner on the latent image. If the specific volume resistivity of the carrier is low, the carrier is likely to adhere to the photosensitive surface. On the other hand, a solid black images of uneven density is reproduced due to a strong edge effect if the specific volume resistivity of the carrier is high. Therefore, the carrier is required to have a low specific volume resistivity in the developing zone where the carrier is exposed to a high electric field due to the high bias voltage. Also, it is desirable for the carrier to have a high specific volume resistivity in the region other than the developing zone, because the charge amount of the toner is reduced due to leak if the specific volume resistivity is low. Thus, the specific volume resistivity of the carrier is preferred to be high in a low electric field, and low in a high electric field. However, the carrier in the prior art is insensitive to the change of the electric field.
Generally, the ability of the ferrite carrier to provide the toner with triboelectric charge largely depends on the chemical composition of the carrier. The known Ni--Zn ferrite, Mn--Zn ferrite, Cu--Zn ferrite, etc. provide a polyester-based toner of a strong negative chargeability with too much amount of charge which results in a reproduced image with insufficient density and a charge-up. Also, such ferrite carriers are less effective to charge a positively chargeable toner such as a styrene-acryl-based toner, and produce images with background foggings.

Ferrite carrier, two-component developer and electrostatic imaging method using the developer


Signal transition feature based coding for serial link is described herein. According to one embodiment, in response to a data stream transmitted onto a serial communication link, one or more bits of the data stream are encoded according to bit order determined based on a frequency of signal transitions of the data stream. As a result, a sequence of encoded data stream having a lower number of bit transitions with respect to the frequency of signal transitions of the data stream prior to the encoding is generated. Thereafter, the encoded data sequence is transmitted onto the serial communication link. Other methods and apparatuses are also described.

For circuits optimized for low-power, the power dissipated at the I/O (input/output circuit) is typically around 50% of the total power consumption. This I/O power dissipation is a consequence of relatively large dimensions of devices in the I/O pads and of the external-capacitances due to I/O pins, wires, and connected circuits. The devices in the I/O need to be large in order to drive the large external capacitances and this further increases their own parasitic capacitances. The capacitances on printed circuit boards are about two orders of magnitude larger than that inside of a chip. Dynamic charging and discharging these capacitances causes I/O pins to consume a relatively large amount of power.
Coding the I/O for lower power consumption has been utilized recently. Coding I/O for low power is practical and has been implemented in commercial chips. However, most of the conventional approaches are designed for parallel buses.


An organic EL element including: pixel electrode on a section of TFT substrate corresponding to pixel region; auxiliary connector on a section of TFT substrate corresponding to auxiliary region; hole injection layer on pixel electrode and auxiliary connector; and light-emitting layer on a section of hole injection layer corresponding to pixel region. The organic EL element additionally includes: electron injection layer on light-emitting layer and a section of hole injection layer corresponding to auxiliary region; and seamless common electrode on electron injection layer. Hole injection layer contains WOx. Electron injection layer contains NaF. Common electrode contains Al that causes the reduction of NaF contained in electron injection layer.

In recent years, progress is being made in research and development of diverse functional elements which involve the use of an organic semiconductor. One typical example of a functional element is an organic EL element. An organic EL element is a current-driven light-emitting element, and commonly has a pair of electrodes, namely a pixel electrode and a common electrode, and functional layers layered between the pair of electrodes. The functional layers include a light-emitting layer composed of an organic material. Upon application of voltage across the pair of electrodes, holes injected from the pixel electrode to the functional layers recombine with electrons injected from the common electrode to the functional layers. The recombination causes the phenomenon of electroluminescence, which involves emission of light. Given the high visibility of organic EL elements resulting from their self-luminescence, as well as their excellent shock resistance resulting from the fully solid-state structure thereof, more attention is now being given to the application of organic EL elements as a light-emitting element for various organic EL display panels and organic EL display apparatuses or a light source.
Generally, a common electrode of an organic EL display panel is disposed to cover the entire surface of the panel on which organic EL elements are arranged. At the periphery of the panel, the common electrode is connected to a voltage source so that voltage is externally applied to the common electrode. Due to this structure, the central area of the panel is supplied with voltage from the voltage source via an electrical resistance of the common electrode. Therefore, the voltages applied to the light-emitting layer in the central area and in the peripheral area of the panel might vary greatly despite the same voltage supplied from the voltage source, and accordingly the luminance of each organic EL element might differ from each other. To solve this problem, there has been a proposal of the use of, in addition to the common electrode, an auxiliary connector having a lower resistance than the common electrode, and thereby reducing the difference among the voltages applied to the light-emitting layers in the panel (Patent Literature 1).

Organic EL element, organic EL panel, organic EL light-emitting apparatus and organic EL display apparatus


A method of ultrasonic welding of plastic members to form a high strength interconnection between the members in the form of a low profile, illuminated electrical plug. High-frequency (ultrasonic) energy is transmitted by the ultrasonic welding apparatus to compatible plastic parts of the low profile electrical plug. At the intersection of the two parts, a combination of applied force and surface and/or intermolecular friction increases the temperature until the melting point of the thermoplastic is reached. Upon removal of the ultrasonic energy, a bond is produced between the plastic parts, effectively affixing them together in the desired fashion.

Low profile electrical plugs are typically manufactured using an injection molding method. U.S. Pat. No. 5,182,032 to Dickie discloses an injection molding apparatus in which non-rigid or flexible components intended to be encapsulated within the interior of an injection molded product is provided.
Although injection molding is an effective method of manufacturing of low profile electrical plugs, it has been determined that ultrasonic welding the desired portions of the plug is a more accurate and less expensive procedure. In addition, injection molding requires that the same material be used to encapsulate the electrical components within the plug, making it difficult to produce hollow cavities and incorporate dissimilar materials to act as transparent or translucent windows. As such, if the plug is to incorporate an electrically illuminated lamp, as in the present invention, injection molding of the plug becomes problematic
Ultrasonic assembly is well-known, and is suitable for most thermoplastic materials. In practice, high-frequency (ultrasonic) energy is transmitted by the ultrasonic welding apparatus to compatible plastic parts. At the intersection of the two parts, a combination of applied force and surface and/or intermolecular friction increases the temperature until the melting point of the thermoplastic is reached. Upon removal of the ultrasonic energy, a bond is produced between the plastic parts, effectively affixing them together in the desired fashion.
Typical systems used for ultrasonic welding contain a high-frequency power supply (20-40 kHz). Energy from the power supply is directed into a horn dimensioned to be resident at the applied frequency. Upon contact with the workpiece, the horn transmits the energy into it. The two parts to be welded are aligned in the proper fashion by a support constructed of aluminum or steel.
Accordingly, it is therefore a general object of the present invention to provide a method of manufacturing a low profile, illuminated electrical plug using an ultrasonic welding process that is less expensive and more accurate than conventional injection molding methods.

Ultrasonically welded electrical plug including illuminated indicator


The disclosure provides, among other things, molecular markers for categorizing the neoplastic state of a patient, methods for using the molecular markers in diagnostic tests, nucleic acid and amino acid sequences related to the molecular markers, reagents for detection of molecular markers, and methods for identifying candidate molecular markers in highly parallel gene expression data.

Colorectal cancer, also referred to herein as colon cancer, is the second leading cause of cancer mortality in the adult American population. An estimated 135,000 new cases of colon cancer occur each year. Although many people die of colon cancer, early stage colon cancers are often treatable by surgical removal (resection) of the affected tissue. Surgical treatment can be combined with chemotherapeutic agents to achieve an even higher survival rate in certain colon cancers. However, the survival rate drops to 5% or less over five years in patients with metastatic (late stage) colon cancer.
Effective screening and early identification of affected patients coupled with appropriate therapeutic intervention is proven to reduce the number of colon cancer mortalities. It is estimated that 74,000,000 older Americans would benefit from regular screening for colon cancer and precancerous colon adenomas (together, adenomas and colon cancers may be referred to as colon neoplasias). However, present systems for screening for colon neoplasia are inadequate. For example, the Fecal Occult Blood Test involves testing a stool sample from a patient for the presence of blood. This test is relatively simple and inexpensive, but it often fails to detect colon neoplasia (low sensitivity) and often even when blood is detected in the stool, a colon neoplasia is not present (low specificity). Flexible sigmoidoscopy involves the insertion of a short scope into the rectum to visually inspect the lower third of the colon. Because the sigmoidoscope is relatively short, it is also a relatively uncomplicated diagnostic method. However, nearly half of all colon neoplasia occurs in the upper portions of the colon that can not be viewed with the sigmoidoscope. Colonoscopy, in which a scope is threaded through the entire length of the colon, provides a very reliable method of detecting colon neoplasia in a subject, but colonoscopy is costly, time consuming and requires sedation of the patient.
Modem molecular biology has made it possible to identify proteins and nucleic acids that are specifically associated with certain physiological states. These molecular markers have revolutionized diagnostics for a variety of health conditions ranging from pregnancy to viral infections, such as HIV.
Researchers generally identify molecular markers for a health condition by searching for genes and proteins that are expressed at different levels in one health condition versus another (e.g. in pregnant women versus women who are not pregnant). Traditional methods for pursuing this research, such as Northern blots and reverse transcriptase polymerase chain reaction, allow a researcher to study only a handful of potential molecular markers at a time. Microarrays, consisting of an ordered array of hundreds or thousands of probes for detection of hundreds or thousands of gene transcripts, allow researchers to gather data on many potential molecular markers in a single experiment. Researchers now face the challenge of sifting through large quantities of microarray-generated gene expression data to identify genes that may be of genuine use as molecular markers to distinguish different health conditions.
Improved systems for identifying high quality candidate molecular markers in large volumes of gene expression data may help to unlock the power of such tools and increase the likelihood of identifying a molecular marker for important disease states, such as colon neoplasia. Effective molecular markers for colon neoplasia could potentially revolutionize the diagnosis, management and overall health impact of colon cancer.

Methods and compositions for categorizing patients


A charged particle detector is provided. The charged particle detector includes a flexible semiconductor wafer, the semiconductor wafer being doped to form a p-n junction, and an amplifier coupled to the semiconductor wafer and configured to amplify a current or voltage across the p-n junction.

The decommissioning of nuclear sites requires reliable techniques for the detection, identification and quantification of radioactive substances. In this scenario, the discrimination between disposable and contaminated waste is mainly driven by the cost of decommissioning. The UK government has already forecasted a cost of at least £117 billion for decommissioning UK nuclear sites over the next century. New technologies and solutions therefore need to be explored in order to reduce the associated financial figure and to speed up the decommissioning progress.
In particular, there is no low-cost solution available for assessing the presence of alpha-radioactive sources, such as plutonium, inside pipework. The emission of alpha-particles is an intrinsically short range process (a few cm in air, a few mm or microns in solid material) and as such undetectable from the outside of the pipe, as any radiation occurring on the inside of the pipe is absorbed by the pipe wall. Consequently, alpha-particle detectors must be positioned inside a pipe and as close as possible to the inner walls to ensure effective detection.
Pipeline inspection gauges (PIGs) are routinely used in surveys of the internal condition of pipes. Potential alpha contamination could thus be located by arranging multiple detectors around a PIG. However, the efficiency of alpha-detection is then dependent upon the number of detectors. Each detector is flat, so the larger each individual detector, the greater the average distance to the pipe wall. A ring of many individual detectors which closely approximates a circle would be expensive and cumbersome.
Conventional monitoring instruments are instead based on a multi-step, indirect and hence less-efficient detection mechanism. For example, if alpha-particles excite a fluorescent material, like molecular nitrogen in air, it will relax to its ground state by the emission of light. Scintillation detectors are able to relate the induced luminescence to the presence of radioactivity. However, they are not very sensitive to the type of primary particle, because the luminescence caused by charged particles is mostly proportional to the energy loss in the media.
A more recent and efficient detection method bases upon the measurement of air-driving ions: if ambient air is struck by alpha particles, the ionized air molecules can be driven to an ionization chamber via a fan. Modelling the airspeed distribution inside the pipe makes it possible to determine the drifted distance from the source to the chamber, and so to locate the alpha-radiation. However, as this method requires a testing chamber for inspection, each pipe must be cut into segments—which may not be possible for the inspection of a long pipework.
Similar issues are faced in high-energy particle experiments. There is a need to detect energetic charged particles, which is currently done with a plurality of detectors arrayed around and within the beam pipe, each defining a pixel. However, damage to individual pixels often requires expensive replacements, and the choice of number of detectors is a trade-off between accuracy (more detectors allows a closer approximation to cylindrical geometry) and cost.


A projection data rebinning device for nearest-neighbor rebinning in Positron Emission Tomography (PET) using on-line 3D axial LOR-to-bin mapping. The PETLINK™ DMA Rebinner (PDR) of the present invention includes a PCI card for on-line translation of detector-pair event packets into bin-address packets. The PDR delivers accurate axial and transaxial LOR nearest-neighbor rebinning and enables the more oblique LOR to be mapped into the proper sinogram bins. The PDR is used in association with hardware architecture in electrical communication with a medical imaging device. The data acquisition architecture includes a processor, random access memory (RAM), an operating system, and a data storage device. The PDR includes a plurality of FPGAs and flash chips. The FPGAs are in communication with each other via a high-bandwidth connection. The flash memory chips are used for look-up tables. The PDR performs on-line translation of detector-pair event packets into bin-address packets.

1. Field of Invention
The present invention pertains to the field of Positron Emission Tomography (PET). More particularly, this invention is directed to a device for improving the speed and accuracy of on-line three-dimensional (3D) LOR-to-bin mapping.
2. Description of the Related Art
Various techniques are used for medical imaging. Positron emission tomography (PET) is one of several popular methods in radiology because of its ability to non-invasively study physiological processes and structures within the body. PET is a nuclear imaging technique used in the medical field to assist in the diagnosis of diseases. PET allows the physician to examine the whole patient at once by producing pictures of many functions of the human body unobtainable by other imaging techniques. In this regard, PET displays images of how the body works (physiology or function) instead of simply how it looks. PET is considered the most sensitive, and exhibits the greatest quantification accuracy, of any nuclear medicine imaging instrument available at the present time. Applications requiring this sensitivity and accuracy include those in the fields of oncology, cardiology, and neurology.
In PET, short-lived positron-emitting isotopes, referred to as radiopharmaceuticals, are injected into a patient. When these radioactive drugs are administered to a patient, they distribute within the body according to the physiologic pathways associated with their stable counterparts. As the radiopharmaceutical isotopes decay in the body, they discharge positively charged particles called positrons. Upon discharge, the positrons encounter electrons, and both are annihilated. As a result of each annihilation event, gamma rays are generated in the form of a pair of diametrically opposed photons approximately 180 degrees (angular) apart. After the PET scanner detects these annihilation "event pairs" over a period of time, the isotope distribution in a cross section of the body is reconstructed. These events are mapped within the patient's body, thus allowing for the quantitative measurement of metabolic, biochemical, and functional activity in living tissue. More specifically, PET images (often in conjunction with an assumed physiologic model) are used to evaluate a variety of physiologic parameters such as glucose metabolic rate, cerebral blood flow, tissue viability, oxygen metabolism, and in vivo brain neuron activity.
In PET, it is well know that data acquisition is limited by several physical constraints of the hardware implemented. A fundamental requirement for 3-D PET is the proper positioning of each coincidence event into the 3-D projection data space. Rebinning is a positioning calculation which may use a nearest-neighbor LOR-to-projection-bin mapping. When rebinning is performed rapidly, higher patient throughput results. High-sensitivity, high-resolution PET requires that more complex rebinning calculations be performed at higher rates. These requirements place increasing demands on the data acquisition electronics.
The pursuit of greater sensitivity in 3-D PET typically leads to ever-larger detector arrays and higher count rates. Preserving good image resolution in larger detector arrays requires more complex calculations. In the present case, more calculations are required for properly positioning coincidence LORs into the 3-D projection data space. As a result of this progression, algorithms and electronic architectures which were once adequate for the smaller, shorter-axis detector arrays are no longer adequate. As the axial extent of the detector array increases, the data acquired from conventional algorithms degrades. Accordingly, algorithms and electronic architectures required to service on-line rebinning for larger, longer-axis PET detector arrays must be improved, especially where image resolution is critical. One example of a long-axis high-resolution PET is described by Wienhard et al., "The ECAT HRRT: Performance and First Clinical Application of the New High Resolution Research Tomograph," IEEE Trans. Nucl. Sci., vol. 49, pp. 104-110 (2002). With an eye toward the clinical needs of high patient throughput, challenges to the on-line electronics include more complex rebinning algorithms and higher rebinning rates.
In earlier work on digital pipelines for on-line PET rebinning, flash memory chips used as look-up tables (LUT) were applied in various pipeline stages using programmable logic. See, for example, W. Jones, et al., "LSO PET/SPECT Spatial Resolution: Critical On-line DOI Rebinning Methods and Results," IEEE MIC Conf. Rec., (2000); and W. Jones, et al., "First Time Measurement of Transaxial Resolution for a New High-Sensitivity PET Prototype Using 5 LSO Panel Detectors," IEEE MIC Conf. Rec., (2002).

Nearest-neighbor rebinning in clinical PET using on-line three dimensional LOR-to-bin mapping


An ac generator for a vehicle includes a rotor for providing a magnetic field, a stator having a stator core in which a plurality of phase-windings is mounted to generate electromotive force when the magnetic field is supplied, a rectifying unit which includes positive electrode side rectifying elements and negative electrode side rectifying elements respectively connected to the plurality of phase-windings. One of the positive electrode side rectifying element and negative electrode side rectifying element that is connected to a portion of the phase-windings is constituted of a single element and the remainders are constituted of parallelly connected two elements.

1. Field of the Invention
The present invention relates to an ac generator for a vehicle to be mounted in a vehicle or the like.
2. Description of the Related Art
An ac generator for a vehicle generates electric power by means of mechanical power that is supplied by an engine so as to charge a battery and supply electric power for engine ignition, illumination and operation of various electrical accessories. It is very important to make such an ac generator more compact, lighter in weight, more powerful and less expensive, in view of market competition.
Recently, various electric accessories have been adopted in order to comply with various laws and regulations and market demand for more sophisticated vehicles. Accordingly, power consumption of the vehicle has increased and heat generation by the ac generator increases, so that temperature of various parts becomes very high. Further, the increase in the various electrical accessories increases the degree of accumulation of the engine compartment, resulting in increasing the temperature of the engine compartment. Thus, it is very important to reduce the temperature of an ac generator.
In particular, temperature of the rectifying unit, which is disposed near other accessories, becomes higher than other accessories because it generates more heat as more current is supplied by the ac generator and because it is affected by heat radiation from other accessories. Therefore, it is the most important to reduce temperature of the rectifying unit.
Recently, a vehicle is equipped with various electronically controlled devices which includes an ECU (engine control unit). In such a vehicle, if a surge voltage is generated by the ac generator due to breakdown of a power line of the ac generator or abrupt shutdown of an electric load, the ECU or other devices may fail. Therefore, it is necessary to suppress such a surge voltage.
The following is disclosed in JP-A-4-244770 (pages 2–3, FIGS. 1–2) as one of conventional ways of cooling a rectifying unit: the negative electrode side heat sink of the rectifying unit is contacted with a generator housing and the positive electrode side heat sink is contacted with metal cover via a insulating member so that the rectifying unit can be cooled by way of heat transfer.
The following is also disclosed in French Laid Open Patent Application 2734426 (FIG. 1) as another way of cooling a rectifying unit: the negative electrode side rectifying element is not fixed to a heat sink but is directly force-fitted to a hole of the housing so as to directly transmit the heat generated by the rectifying element to the housing.
As disclosed in JP-A-64-8872 (Pages 2–3, FIGS. 1–2) , it is well known as a conventional art of suppressing surge voltage that all the rectifying elements are zener diodes. Further, there is a rectifying unit, as disclosed in JP-B2-4-24945 (page 2, FIGS. 1–3), in which the zener diodes are used in one group of the positive electrode side rectifying elements or the negative electrode side rectifying elements and normal diodes are used in the other group.
The rectifying unit of an ac generator for a vehicle disclosed in JP-A-4-244770 has an aim of cooling the rectifying unit by heat transfer from the heat sink to the housing or the metal cover. However, the temperature of the housing becomes very high because the housing encloses a stator core the temperature of which is the highest in the ac generator. Therefore, the heat transfer from the negative electrode side heat sink is not effectively carried out. In other words, a sufficient cooling effect can not be achieved.
The rectifying unit disclosed in French Laid Open Patent Application 2734426 has an aim of providing highly efficient heat transfer for better cooling effect by direct force-fit into the housing. However, a sufficient cooling effect can not be provided because the temperature of the housing becomes very high, as stated above. The positive electrode side heat sink does not particularly increase the cooling effect, resulting in insufficient cooling.
It is well known to use zener diodes for all the rectifying elements in order to suppress the surge voltage. In fact, the zener diodes have been widely utilized for that purpose. However, the zener diode is more expensive than the normal diode, resulting in increase in the cost of the ac generator. The rectifying unit disclosed in JP-A-64-8872 includes normal diodes for the positive electrode side rectifying element and zener diodes for the negative electrode side rectifying elements. In this rectifying unit, a high backward voltage may be applied to the normal diodes, so that a surge voltage may go out of an ac generator to an electronic device such as an ECU, which may be badly affected.
The rectifying unit disclosed in JP-B2-4-24945 has much more rectifying elements, and it is difficult to reduce the size and weight of an ac generator for a vehicle and the production cost thereof.

AC generator for vehicle having rectifying unit


In some examples, in response to a request from a client device for information relating to a transaction stored by a blockchain, a system identifies, using information stored in a distributed storage system that stores data for the blockchain, multiple data owner entities from which permissions are to be obtained for access of the information, and determines an authorization requirement for the information based on a smart contract. The system sends authorization information based on the authorization requirement to trigger a retrieval of authorization tokens from the identified data owner entities for access of the information, and sends the information to the client device in response to receiving the authorization tokens.

A storage system can store information for which requests can be submitted by client devices for access to the information. In some cases, access to the storage system can be granted by a server that manages access to the information in the storage system. Traditionally, an access control and/or policy management system determines whether a client device is allowed to access to requested information in the storage system.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

Permissions from entities to access information

Hewlett Packard Enterprise Development LP


The present invention relates to an alkali-free glass substrate in which when the alkali-free glass substrate is melted, and while holding a temperature at 1400° C., reduced in pressure from an atmospheric pressure to 33.33 kPa at a constant pressure reduction rate for 20 minutes and held at 33.33 kPa for 5 minutes, a diameter of a grown bubble is at least 3 times a diameter of an initial bubble. A bubble having a diameter of 0.1 to 0.3 mm contained in a molten glass at 1400° C. before starting pressure reduction is defined as the initial bubble. A bubble after held at 33.33 kPa for 5 minutes corresponding to the initial bubble is defined as a grown bubble.

An alkali-free glass substrate which does not substantially contain alkali metal ions is preferably used for a glass substrate for various displays, particularly one in which a metal, an oxide thin film or the like is formed on a surface thereof, because when an alkali metal oxide is contained, the alkali metal ions diffuse in the thin film to deteriorate film properties.
A glass raw material prepared at a predetermined compounding ratio is melted in a melting tank to be vitrified, the molten glass is fined and thereafter formed into a glass ribbon having a predetermined sheet thickness by a float process or a fusion process, and this glass ribbon is cut into a predetermined shape, thereby obtaining the alkali-free glass substrate used for the purpose described above.
In the refining of the molten glass, there has been known a vacuum degassing method of introducing the molten glass into a reduced pressure atmosphere, allowing bubbles in a continuous flow of molten glass to largely grow under the reduced pressure atmosphere to raise the bubbles contained in the molten glass, breaking and removing the bubbles, and thereafter, discharging the molten glass from the reduced pressure atmosphere. For example, Patent Document 1 discloses a glass production method comprising a step of subjecting molten glass to vacuum degassing in a vacuum degassing vessel.


A device for inoculating fluid conducted through pipes includes a reservoir configured to hold an inoculant. The reservoir includes an outlet through which the inoculant is feedable to at least one of the pipes and an inlet configured to route compressed air into an interior of the reservoir.

A device for inoculating a fluid conducted through pipes is described in DE 1 242 575 A1. The device is used to inoculate water flowing, e.g., through the piping of a water supply system. The device has a reservoir of the flexible bag type, filled with inoculant. In order to transport the inoculant from the reservoir, the device uses the energy of the water's flow. For this purpose, a throttle plate is incorporated into the cross-section of the pipe through which the water flows. However, the throttle plate narrows the pipe's cross-section. This favors deposits in the throttle plate area, which interrupt the transport mechanism for the inoculant, having a negative impact on the function of the device.

Device for inoculating a fluid conducted through pipes