A self-propelled work machine, in which the load of the work unit increases according to an increase in the travel speed. The self-propelled work machine includes electric motors for driving the travel units, an engine for driving the work unit, a work drive instruction unit for instructing the work unit to turn on, and a control unit for controlling the electric motors. The control unit reduces the actual speed of the electric motors by using PID control so that the actual rotational speed of the engine returns to a reference rotational speed when the actual rotational speed of the engine falls below the reference rotational speed in the state in which the work unit is turned on by the work drive instruction unit. The reference rotational speed is a reference value used when the work unit is driven by the engine.

The load placed on a work unit increases according to the travel speed or work conditions in some self-propelled work machines such as, for example, auger-type snow removers that are provided with an engine-driven work unit. An auger-type snow remover is a work machine in which snow is gathered and removed using an auger (work unit) at the front of the machine while the machine travels forward. As the travel speed increases, the amount of snow removed by the auger also increases. As a result, the load placed on the auger increases. This type of auger-type snow remover is described in Japanese Utility Model Laid-Open Publication No. 3-32617, and Japanese Patent Laid-Open Publication Nos. 2004-278055 and 2002-142307.
In the auger-type snow remover described in Japanese Utility Model Laid-Open Publication No. 3-32617, the travel speed of the travel unit is varied when the load placed on the auger changes according to the type or accumulated amount of snow.
In the auger-type snow remover described in Japanese Patent Laid-Open Publication No. 2004-278055, notification is given by an indicator lamp when the actual rotational speed of the engine increases or decreases in relation to a target rotational speed. The rotational speed of the engine is thereby varied according to fluctuation of the load exerted on the auger. An operator may therefore change the travel speed of the auger-type snow remover on the basis of the indication by the indicator lamp. As a result, the actual rotational speed of the engine can be matched to the target rotational speed.
In the auger-type snow remover described in Japanese Patent Laid-Open Publication No. 2002-142307, a machine body provided with a snow-removing work unit is moved along by a travel unit, and the snow-removing work unit is driven by an engine.
The auger-type snow remover (self-propelled work machine) described in Japanese Utility Model Laid-Open Publication No. 3-32617 will be described herein with reference to FIGS. 18A and 18B as an example of the abovementioned prior art. FIGS. 18A and 18B are schematic views of the conventional self-propelled work machine. FIG. 18A is a side view of the self-propelled work machine. FIG. 18B is a schematic view of the self-propelled work machine.
The conventional self-propelled work machine 100 (auger-type snow remover 100) is composed of a snow-removing work unit 101, a machine body 102 to which the snow-removing work unit 101 is provided, and a travel unit 103. The snow-removing work unit 101 is composed of an auger 111, a blower 112, and a shooter 113. The travel unit 103 is composed of a crawler. An engine constitutes a drive source 104 for driving the snow-removing work unit 101 and the travel unit 103.
In this auger-type snow remover 100, the type and accumulated amount of snow removed can be estimated by a control unit 123 on the basis of the rotational speed of the engine 104 detected by a speed sensor 121, and on the load torque of the snow-removing work unit 101 detected by a torque sensor 122. The control unit 123 controls the speed of the travel unit 103, auger 111, and blower 112 on the basis of the results of this estimation.
Specifically, the control unit 123 reduces the speed of the travel unit 103 and increases the speed of the auger 111 and blower 112 when it is estimated that the snow type is icy and the snow coverage is low in the portion of snow removed. The control unit 123 also reduces the speed of the travel unit 103, auger 111, and blower 112 when it is estimated that the snow type is regular (soft snow or the like) and the snow coverage is high.
However, it is often the case that the snow type or coverage of the portion of snow removed varies continuously. As in the auger-type snow remover 100, when the load exerted on the snow-removing work unit 101 varies according to the snow type or amount of the portion of snow removed, merely changing the travel speed of the travel unit 103 will cause frequent repetitions of deceleration and acceleration with each variation of the load. For example, frequent significant changes in the travel speed during snow removal are bothersome to the operator. Improvements can be made in order to increase ease of operation. Regardless of the travel speed or the size of the load, the speed is sometimes too low when a simple deceleration to a constant travel speed is made each time the load increases, and there is potential for improving the ease of operation in this aspect as well.
There is also potential for making it easier to operate an auger-type snow removers such as the one described in Japanese Laid-open Patent Application No. 2004-278055, wherein operation is made inconvenient by the fact that the operator must frequently change the travel speed each time the load on the auger changes according to the snow type or amount of the portion of snow removed.
Since snow is removed at low temperatures, a relatively long time is required from the time the engine 104 is started until the warm-up operation (warm-up) is completed. The operator is therefore inconvenienced by the need to wait without removing the snow until the warm-up is completed. The warm-up operation performed manually by the operator involves first closing a choke valve, and then gradually opening the choke valve according to the warm-up state.
Because of the inconvenience of this operation, the use of an automatic choke is considered. An automatic choke is a device for automatically opening and closing the choke valve according to the temperature state of the engine. The device is also referred to as an auto-choke. In other words, a configuration may be adopted in which the valve travel of the choke valve and throttle valve of the engine are adjusted by an electronic governor. Various types of such devices are known.
For example, a work machine equipped with an engine in which the valve travel of the throttle valve is adjusted by an electronic governor is described in Japanese Patent No. 2832610. In the work machine described in Japanese Patent No. 2832610, an electronic-governor throttle valve is provided to an engine mounted to a rice planting machine or a cultivator. An automatic choke may be fixed on the engine of this work machine.
An additional description will now be given with reference to FIGS. 18A and 18B. A case can be envisioned in which an electronic governor is employed for adjusting the valve travel of a choke valve and throttle valve in the engine 104 of a conventional auger-type snow remover 100. The warm-up operation is performed with the choke closed, but the load placed on the engine 104 is large when the auger-type snow remover 100 is moved forward and snow removal is started in this state.
This situation is particularly likely to occur when the travel unit 103 is made separate from the drive system actuated by the engine 104 and is part of a drive system actuated by an electric motor. This occurs because the auger-type snow remover 100 is caused to advance despite of the fact that the engine 104 is still warming up.
The performance of a common snow remover in a case in which the travel unit 103 is part of an electric motor drive system will be described with reference to FIG. 19.
FIG. 19 is a diagram describing the performance of the conventional auger-type snow remover. The drawing shows the performance of the auger-type snow remover. The elapsed time is plotted on the horizontal axis, the throttle valve travel Str is plotted on the vertical axis on the left side of the diagram, and the choke valve travel Cr and the actual speed Tr of the electric motor are plotted on the vertical axis on the right side of the diagram.
The choke valve travel Cr is 0% at t1 and 100% at t2, where t1 is the time at which the engine is started, and t2 is the time at which the warm-up operation is completed. In other words, the choke valve travel gradually increases in size from 0% to 100% according to the warm-up state.
The throttle valve travel Str increases sharply when the snow-removing work unit is driven by the engine while the travel unit is moved forward by the electric motor at about the same time as the engine is started. This is because a large load is placed on the engine. In other words, the throttle valve travel Str is unnecessarily large.
When a configuration is adopted in which the actual speed Tr of the electric motor is reduced relative to the increase in the throttle valve travel Str, the actual speed Tr of the electric motor sharply decreases with rapid increase in the throttle valve travel Str. Snow is therefore not removed by the auger-type snow remover. There is thus no point in starting to remove the snow early during warming-up of the engine. This technique leaves room for improving the ability to remove snow.
The auger-type snow remover (self-propelled work machine) described in Japanese Laid-open Patent Application No. 2002-142307 will next be described with reference to FIG. 20. FIG. 20 is a schematic diagram of a conventional self-propelled work machine.
The conventional self-propelled work machine 200 (auger-type snow remover 200) is described as being provided with a snow-removing work unit 203 composed of an auger 201 and a blower 202, an engine 205 for driving the snow-removing work unit 203 via a clutch 204, left and right travel units 206 and 206 composed of crawlers, left and right electric motors 207 and 207 for driving the travel units 206 and 206, left and right brakes 208 and 208 for applying braking to the travel units 206 and 206, a control unit 209 for controlling the electric motors 207 and 207 or the brakes 208 and 208, and various types of operating members 211, 213, 214, and 214 for issuing operating signals to the control unit 209.
The travel of the throttle valve 212 of the engine 205 can be adjusted by operating a throttle lever 211. The rotational speed of the engine 205 increases as the throttle valve 212 is opened.
The control unit 209 controls the direction or speed of rotation of the left and right electric motors 207 and 207 according to the operation of an accelerator lever 213, and controls the left and right brakes 208 and 208 according to the operation of speed adjustment levers 214 and 214.
The auger-type snow remover 200 thus configured is a type of work machine in which a snow-removing work unit 203 is driven by an engine 205, and travel units 206 and 206 are driven by electric motors 207 and 207.
By operating a clutch operating member (not shown) to switch on the clutch 204, the snow-removing work unit 203 can be driven by the power of the engine 205 to remove snow. The rotational speed of the engine 205 is reduced according to the size of the load placed on the snow-removing work unit 203. The travel of the throttle valve 212 is automatically increased according to the degree of speed reduction in order to maintain the desired rotational speed. The control unit 209 causes the travel speed of the travel units 206 and 206 to decrease by reducing the speed of the electric motors 207 and 207 according to the reduction in the rotational speed of the engine 205 or the increase of in the travel of the throttle valve 212. Specifically, the auger-type snow remover 200 is propelled at the travel speed that corresponds to the snow removal load.
The characteristics of a common auger-type snow remover 200 in a case in which the travel units 206 and 206 are driven by electric motors will next be described with reference to FIGS. 21A and 21B with reference to FIG. 20.
FIG. 21A is a timing chart in which the elapsed time is plotted on the horizontal axis, and the travel Str of the throttle valve 212 is plotted on the vertical axis. FIG. 21B is a timing chart in which the elapsed time is plotted on the horizontal axis, and the actual speed Tr of the electric motors 207 and 207 is plotted on the vertical axis. The characteristics shown in FIGS. 21A and 21B are correlated between these two diagrams.
At time t21 when the clutch 204 is switched on, a large load is placed on the snow-removing work unit 203 for an extremely short time. As a result, the rotational speed of the engine 205 begins to increase after sharply decreasing for a short time. The travel Str of the throttle valve 212 also changes rapidly for a brief time in conjunction with the rapid change in the rotational speed of the engine 205. The control unit 209 causes the actual speed Tr of the electric motors 207 and 207 to change rapidly for a brief time according to the sudden change in the rotational speed of the engine 205 or the sudden change in the travel Str of the throttle valve 212.
Since the travel speed of the auger-type snow remover 200 is generally low, an operator who is relatively skillful at removing the snow is not inconvenienced at all by this degree of variation in the travel speed. On the other hand, to a novice operator unskilled at removing the snow, travel should preferably be made as stable as possible in order to increase workability.
The same applies at time t22 or t23 when the travel Str of the throttle valve 212 is adjusted by operation of the throttle lever 211. This is because the throttle lever 211 is not necessarily operated smoothly by a novice user unaccustomed to its operation.
Therefore, a technique is needed that is capable of further enhancing the ease of operation of a self-propelled work machine provided with an engine-driven work unit in a machine body that can be self-propelled using an electric motor.


A new cultivar of Hydrangea macrophylla named ‘Blue Knight’ that is characterized by its early blooming habit, its ability to re-bloom on new growth after deadheading, its consistently well-formed, lacecap type inflorescences with large, double, rounded shaped sterile flowers that are light to dark blue under acidic conditions and bright pink under alkaline conditions, its deep green glossy foliage, and its strong stems that enable pot culture without staking.

The present invention relates to a new and distinct cultivar of Hydrangea macrophylla and will be referred to hereafter by its cultivar name, 'Blue Knight'. 'Blue Knight' represents a new bigleaf hydrangea, a deciduous shrub grown for landscape use and for use as a potted plant.
'Blue Knight' was derived from an ongoing controlled breeding program that focuses on new cultivars of Bigleaf Hydrangeas for container and landscape use. 'Blue Knight' originated from a cross made in the Inventor's nursery in June 1999 in Shizuoka, Japan between two unpatented proprietary selections of Hydrangea macrophylla; the female parent designated as H3-67 and the male parent designated as H3-4.The new Hydrangea was selected as a unique single plant from the progeny of the cross in February 2006.
Asexual reproduction of the new cultivar was first accomplished by the Inventor using softwood stem cuttings in Shizuoka, Japan in May 2007. The characteristics of this cultivar have been determined to be stable and are reproduced true to type in successive generations.


A method for synthesizing dyes excitable by a helium-neon laser (excitable at 633 nm) from hololepidines, e. G., 7-halolepidine, which dyes are suitable for the detection and enumeration of reticulocytes in human blood samples. In another aspect, this invention provides a method for immunotyping phenocytes. The method is based on the phenomenon that when dyes of certain structure intercalate into DNA or RNA, the intensity of the dyes increases.

1. Field of the Invention
The present invention relates to dyes that are suitable for staining ribonucleic acid polymers (RNA) and deoxyribonucleic acid polymers (DNA) and are particularly suitable for staining reticulocytes. The invention further relates to a fluorescent composition.
2. Discussion of the Art
In many cases, there is a need to detect RNA or substances containing RNA. For example, a reticulocyte is a substance known to contain RNA. Detection of reticulocytes in a blood sample and the enumeration of these reticulocytes are valuable to clinicians. The reticulocyte count of a blood sample is an indicator of erythropoietic activity, is an indicator of acute hemorrhage and hemolytic anemia, and is a measure of response to iron, vitamin B12, and folic acid therapy. As is known in the art, reticulocytes are precursors of mature red blood cells, and hence the term reticulocyte embraces the evolution and development of a mature red blood cell.
Detection and enumeration of reticulocytes in a blood sample have been carried out by both manual and automated methods by using appropriate stains such as new methylene blue (NMB), brilliant cresyl blue (BCB), acridine orange, and pyronin Y.
Vital staining with the dye new methylene blue is considered to be the reference method for reticulocyte determinations. In use, this dye precipitates RNA. The method is carried out manually and requires counting large numbers of cells with a microscope (for example, 500 to 1,000 cells). Consequently, the method is slow, tedious, and is subject to errors.
New methylene blue is nonfluorescent and true precipitated RNA is often difficult to differentiate from precipitated stain. New methylene blue stains by combining with intracellular RNA molecules to form a colored complex, which is visible under microscopic examination on account of its size and color. However, under certain conditions, the dye molecule itself can form complexes with other dye molecules. These dye/dye complexes are indistinguishable from dye/RNA complexes, with the possible result that counts are inaccurate and/or false positives for the specific cell type of interest are obtained. This problem is more likely when the dye solution has not been filtered to remove non-specific dye/dye complexes that have formed.
Acridine orange has been used for staining reticulocytes by both manual and automated procedures. Acridine orange, which is fluorescent, also precipitates RNA. Consequently, the use of this dye prevents quantitative estimates of RNA content because of potential quenching, a phenomenon caused by dye molecules interfering with one another in the energy transfer process. Under quenching conditions, the energy transfer process results in no net fluorescence emission.
Age profiles of cells based on RNA content being proportional to fluorescence are not reliable. Age profile is the key information sought to be derived in assays of blood cells. The function of the dye for staining reticulocytes is primarily to determine the percentage of immature red blood cells in the general circulation. The information is needed for determining the homeostasis of the blood cell formation, detection of blood cell related metabolic diseases, and the presence or absence of anemic diseases. Acridine orange has a great affinity for the plastic tubing in flow cytometers, thereby resulting in increased background, consequently requiring lengthy procedures for removing the dye from the flow cytometer tubing. In addition, cells stained by acridine orange are difficult to distinguish from the autofluorescent red cell peak. Finally, the reticulocyte count is usually lower than that obtained with new methylene blue. New methylene blue stains cells by combining with the intracellular RNA to form an insoluble precipitate within the cells. A discrete blue pattern is formed upon the interaction, thereby allowing for easy manual microscopic-evaluation. Detection by means of acridine orange is performed on a flow cytometer. On account of the nature of the diffused pattern, it is difficult to differentiate the specific staining from acridine orange to that of non-specific background. Consequently, if the background is high, the net positive usually will be reduced and result in an artificially low value, compared with the more discrete new methylene blue staining method.
The use of pyronin Y requires prior fixation of the erythrocytes with formalin, is cumbersome, time consuming, and generally yields poor results. Moreover, pyronin Y has a very low quantum efficiency, leading to a very low fluorescent signals.
Accordingly, there is a need for providing a dye better suited for staining reticulocytes so as to provide a procedure for accurately determining reticulocytes in a blood sample.
A dye for staining reticulocytes preferably has the following properties:
1. The dye should not fluoresce in the absence of RNA.
2. The dye should have a good fluorescent quantum yield in the presence of RNA.
3. The dye must exhibit a certain level of water solubility and be able to penetrate the membrane of cells containing RNA.
4. The dye should preferably have an excitation peak at about 633 nm.
U.S. Pat. No. 4,957,870 involves the detection of reticulocytes, RNA, and DNA in human blood samples using a dye having the following structure:
wherein
X represents O, S, Se or C(CH3)2;
R1 represents an alkyl group having from 1 to 6 carbon atoms;
R2 represents an alkyl group having from 1 to 6 carbon atoms;
R3 represents fused benzene, alkyl group having from 1 to 6 carbon atoms, methoxy, or is absent;
R4 represents an alkyl group having from 1 to 6 carbon atoms, ethoxy, or is absent; and
n represents zero or an integer from 1 to 6.
In one aspect, this invention provides a method for synthesizing dyes excitable by a helium-neon laser (excitable at 633 nm). The dyes are preferably derived from heterocyclic compounds, e.g., 7-halolepidine. The dyes are suitable for the detection and enumeration of reticulocytes in human blood samples. In another aspect, this invention provides a method for signal amplification. The method is based on the phenomenon that when dyes of certain structure intercalate into DNA or RNA, the intensity of the dyes increases.
Dyes suitable for this invention can be described as having (a) a first heterocyclic moiety, (b) a second heterocyclic moiety, and (c) a linking group that connects the first and second heterocyclic moieties. Both the first and second heterocyclic moieties must contain at least two rings, preferably fused together. The dye is characterized by conjugation whereby the first moiety is ethylenically conjugated to the second moiety.
The general structure of dyes suitable for use in this invention is shown below:
wherein:
R1, R2, R3, R4 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R1 and R2 taken together, or R2 and R3 taken together, or R3 and R4 taken together represent one or more rings;
R5 represents an alkyl group or an aryl group;
R6, R7, R8, R9 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R6 and R7 taken together, or R7 and R8 taken together, or R8 and R9 taken together represent one or more rings, provided that at least one of R6, R7, R8, R9 represents halogen;
R10 represents an alkyl group or an aryl group;
R11, R12 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R11 and R12 taken together represent one or more rings;
R13 represents hydrogen or an alkyl group;
Y represents S, O, C, or Se, provided that Y is not N;
N represents a number from 0 to 3; and
X31  represents a counter ion.
The ring of the first moiety that is attached to the linking group can be a five-membered or six-membered ring. The ring of the second moiety that is attached to the linking group can be a five-membered or six-membered ring.
R5 and R10 can be the same or different. Preferably, R5 and R10 represent an alkyl group having from 1 to 20 carbon atoms and from 0 to 6 heteroatoms, preferably from 1 to 10 carbon atoms and from 0 to 3 heteroatoms. R5 and R10 can be a straight chain, branched chain, or cyclic group. If R5 of R10 is an alkyl group, the carbon atoms of R5 or R10 can contain substitutents other than hydrogen atoms. R5 and R10 can also be (a) aryl groups, preferably having no more than five rings, more preferably no more than three rings, most preferably no more than one ring, or (b) alkenyl groups, preferably having from 2 to 20 carbon atoms, more preferably from 2 to 10 carbon atoms. If R5 or R10 is an aryl or an alkenyl group, the aryl or alkenyl groups of R5 or R10 can contain substitutents other than hydrogen atoms. R5 and R10 can be heteroaryl group groups, wherein heteroatoms can be selected from the group consisting of nitrogen, sulfur, oxygen, and selenium.
The identities of substituents for R5 and R10 are not critical, but they should be selected so as not to adversely affect the absorption characteristics of the dyes.
With respect to the value of n, there must be sufficient carbon atoms in the linking group to provide the desired absorption characteristics of the dye.
When R6, R7, R8, or R9 is a halogen, the halogen is preferably selected from the group consisting of F, Cl, and l.
If R1, R2, R3, R4, R6, R7, R8, R9, R11, R12, or R13 is alkyl, it preferably contains 1 to 20, more preferably 1 to 10, and most preferably 1 to 6 carbon atoms. If R1, R2, R3, R4, R6, R7, R8, R9, R11, R12, or R13 is aryl, it prefably contain no more than five rings, more preferably no more than three rings, and most preferably no more than one ring. If R1, R2, R3, R4 R6, R7, R8, R9, R11, R12, or R13 is alkyl of aryl, it can contain substituents other than hydrogen. If R1 and R2 taken together, or R2 and R3 taken together, or R3 and R4 taken together, or R6and R7 taken together, or R7and R8 taken together, or R8 and R9 taken together, or R11 and R12 taken together form one or more rings, the rings can be aromatic or non-aromatic. The aromatic rings can be carbocyclic or heteroaromatic, wherein the hetroatoms are selected from the group consisting of nitrogen, sulfur, oxygen, and selenium. Preferably, ring structures formed by the foregoing combinations contain no more than five rings, preferably no more than three rings, and most preferably no more than one ring.
Dyes suitable for this invention exhibit very low background, narrow emission bands, and excellent enhancement when DNA or RNA is present. The dyes are stable to oxygen, moisture, and heat but are slowly decolored when exposed to light.
The dyes of this invention can be used as a signal generating agent for the detection of DNA or RNA. The dyes of this invention are sufficiently sensitive such that they can be used for the detection of reticulocytes in human blood samples on a flow cytometer using helium-neon (He-Ne) laser as the light source. Helium-neon lasers are much less expensive than argon lasers.
As mentioned previously, the dyes of this invention exhibit much higher enhancement, lower background, and smaller emission bandwidth than dyes used in the prior art. The low background and smaller emission bandwidth enables the dyes to be used for high resolution analyses of whole blood and in multiplexing assays.
Dyes suitable for this invention can be described as having a first heterocyclic moiety, a second heterocyclic moiety, and a linking group that connects the first and second heterocyclic moieties. Both the first and second heterocyclic moieties must contain at least two rings, preferably fused together. The dye is characterized by conjugation whereby the first moiety is ethylenically conjugated to the second moiety.
The general structure of dyes suitable for use in this invention is shown below:
wherein:
R1, R2, R3, R4 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R1 and R2 taken together, or R2 and R3 taken together, or R3 and R4taken together represent one or more rings;
R5 represents an alkyl group or an aryl group;
R6, R7, R8, R9 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R6 and R7 taken together, or R7 and R8 taken together, or R8 and R9 taken together represent one or more rings, provided that at least one of R6, R7, R8, R9 represents halogen;
R10 represents an alkyl group or an aryl group;
R11, R12 independently represent a member selected from the group consisting of hydrogen, halogen, cyano, alkyl, aryl, alkylaryl, arylalkyl, or R11 and R12 taken together represent one or more rings;
R13 represents hydrogen or an alkyl group;
Y represents S, O, C, or Se, provided that Y is not N;
N represents a number from 0 to 3; and
Xxe2x88x92 represents a counter ion.
The ring of the first moiety that is attached to the linking group can be a five-membered or six-membered ring. The ring of the second moiety that is attached to the linking group can be a five-membered or six-membered ring.
R5 and R10 can be the same or different. Preferably, R5 and R10 represent an alkyl group having from 1 to 20 carbon atoms and from 0 to 6 heteroatoms, preferably from 1 to 10 carbon atoms and from 0 to 3 heteroatoms. R5 and R10 can be a straight chain, branched chain, or cyclic group. The alkyl groups of R5 and R10 can contain substitutents other than hydrogen atoms. R5 and R10 can also be (a) aryl groups, preferably having no more than five rings, more preferably no more than three rings, most preferably no more than one ring, or (b) alkenyl groups, preferably having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms. The aryl or alkenyl groups of RP and R10 can contain substitutents other than hydrogen atoms.
The identities of substituents for R5 and R10 are not critical, but they should be selected so as not to adversely affect the absorption characteristics of the dyes.
R5 and R10 can be heteroaryl group groups, wherein heteroatoms can be selected from the group consisting of nitrogen, sulfur, oxygen, and selenium.
With respect to the value of n, there must be enough carbon atoms in the linking group to provide the desired absorption characteristics of the dye.
When R6, R7, R8, or R9 is a halogen, the halogen is preferably selected from the group consisting of F, Cl, and l.
If R1, R2, R3, R4, R6, R7, R9, R11, R12, or R13 is alkyl, it preferably contains 1 to 20, more preferably 1 to 10, and most preferably 1 to 6 carbon atoms. If R1, R2, R3, R4, R6, R7, R8, R9, R11, R12, or R13 is aryl, it prefably contains no more than five rings, more preferably no more than three rings, and most preferably no more than one ring. If R1, R2, R3, R4, R6, R7, R8, R9, R11, R12, or R13 is alkyl or aryl, it can contain substituents other than hydrogen. If R1 and R2 taken together, or R2 and R3 taken together, or R3 and R4 taken together, or R6and R7 taken together, or R7and R8taken together, or R8 and R9 taken together, or R11 and R12 taken together form one or more rings, the rings can be aromatic or non-aromatic. The aromatic rings can be carbocyclic or heteroaromatic, wherein the hetroatoms are selected from the group consisting of nitrogen, sulfur, oxygen, and selenium. Preferably, ring structures formed by the foregoing combinations contain no more than five rings, preferably no more than three rings, and most preferably no more than one ring.
Xxe2x88x92represents a counter ion, preferably acetate.
The dyes are preferably soluble in water and stable under conditions of use, such as, for example, in a flow cytometer. The dyes are capable of being linked to a molecule, e.g., a protein or a polymer, through the moiety R5, the moiety R10, or another moiety.
When not bound to a nucleic acid, the dyes of the invention exhibit a strong absorption peak in the range of from about 600 nm to about 630 nm; however, in the unbound state, the dye does not provide either a detectable excitation or emission peak. When the dyes stain the RNA in the reticulocytes, the optical properties of the dye change dramatically. In particular, the absorption curve shifts to a longer wavelength, and the dye exhibits strong fluorescence. For a typical dye useful in this invention, the excitation maximum is at about 633 nm, and the emission maximum is at about 670 nm, giving a Stokes shift of about 40 nm. As a result of the excitation peak of the bound dye being in the order of about 633 nm, the light source for use with the automatic flow cytometer may be a helium-neon laser, which has strong emission at 633 nm. The lack of fluorescence of the dye when not bound to nucleic acid provides low backgrounds and allows an operator to select a fluorescent threshold (or xe2x80x9cgatexe2x80x9d) for a flow cytometer by simply running an unstained control. Although excitation may be effected at other wavelengths, the reticulocytes stained with the dyes described herein are preferably excited at a wavelength of from about 630 nm to about 670 nm. Representative examples of dyes suitable for use in this invention have the following structural formulas. In the following structures, xe2x80x9cPhxe2x80x9d represents the phenyl group, xe2x80x9cArxe2x80x9d represents an aryl group, a single straight line represents xe2x80x94CH3, and a broken line represents xe2x80x94CH2CH3.
The following table sets forth the absorption maximum in nanometers for several dyes suitable for use in this invention.
Dyes suitable for use in this invention can be prepared by
(1) reacting a heterocyclic compound containing at least two fused rings with acetic anhydride and N,Nxe2x80x2-diphenylformamidine or its higher homologs to form a chain-extended intermediate;
(2) reacting the aforementioned chain-extended intermediate with a methylated halolepidine in the presence of a tertiary alkyl amine catalyst under reflux conditions to form the dye.
The resultant dye can then be recovered by precipitation, typically by diethylether. Alternatively, dyes suitable for this invention can be prepared by
(1) reacting a heterocyclic compound containing at least two fused rings and an activated methyl group with acetic anhydride and N,Nxe2x80x2-diphenylformamidine or its higher homologs to form a chain-extended intermediate;
(2) reacting the aforementioned chain-extended intermediate with a haloepidine in the presence of a tertiary alkyl amine catalyst under reflux conditions to form the dye.
The resultant dye can then be recovered by precipitation, typically by diethylether.
Representative examples of compounds containing at least two fused rings include 2-methyl-N-benzothiazolium iodide, 2-methyl-N-alkyl benzoxazolium iodide, 2-methyl-N-alkyl naphthoxazolium iodide, and 2-methyl-N-alkyl naphthothiazolium iodide. Representative examples of N-methylated halolepines include 7-chlorolepidine, 7-fluorolepidine, and 7-bromolepidine.
Dyes suitable for use in this invention can be prepared according to the following scheme of synthesis. In the following scheme of synthesis, xe2x80x9cPhxe2x80x9d represents the phenyl group and xe2x80x9cAcxe2x80x9drepresents the acyl group, and xe2x80x9cXxe2x80x9drepresents the halo group.
In the foregoing scheme of synthesis, representative sets of the substituents R and X include the following:
In accordance with the present invention, the dyes of the invention may be employed in the form of an aqueous solution when staining reticulocytes in a blood sample and, in particular, in the form of an isotonic saline solution. The saline solution may contain a minor amount of methanol. The blood sample, which may be whole blood or a blood fraction, is stained with the dye by mixing the blood sample with the solution comprising the dye. It has been found that by using the dyes described herein as the staining medium, it is possible to detect and enumerate reticulocytes in a whole blood sample.
Because the dye must permeate the reticulocyte, it should have excellent cell-permeation properties. The dyes suitable for this invention do not precipitate RNA, and as a result, the stained reticulocyte cells maintain a relatively homogeneous distribution of intracellular RNA, whereby it is possible to designate a threshold value demarcating the distinction between a reticulocyte and a mature red cell. This characteristic provides the physician with additional information beyond the reticulocyte count in that RNA content is a function of the age of the reticulocytes. Accordingly, by using a dye described herein, a clinician has the ability to perform reticulocyte age profiles as well as simple reticulocyte counts. The use of dyes described herein for staining reticulocytes in blood sample offers the further advantage that the fluorescent signals from the stained reticulocytes are readily distinguishable from those of the mature erythrocytes, which contain no RNA or DNA. For this reason, results can be directly read in a flow cytometer without extensive data manipulation.
Although reticulocytes and RNA or DNA stained with a dye of the invention are preferably enumerated in an automatic flow cytometer, they can also be counted by a manual procedure or automated microscopy.
The present invention is not limited to the use of any particular flow cytometer. Thus, for example, stained reticulocytes may be detected and enumerated in an automated flow cytometer or a semi-automated flow cytometer or a manual flow cytometer. In using automated flow cytometers, fluorescent gates are set by use of an unstained control sample, and the fluorescent gates are then used on the stained sample.
The dyes described herein can be used directly to stain reticulocytes. They need not be attached to an antibody or the like to form a conjugate. Staining can be brought about by an-intercalation mechanism, whereby intercalation of the dye with RNA or DNA of the reticulocyte causes a blue shift or a red shift in excitation or emission wavelength.
Alternatively, the dyes described herein can be used in the form of a conjugate. One application of using a conjugate comprising a dye described herein is in a flow cytometry application that employs a fluorescent conjugate or multiple fluorescent conjugates to detect cells contained in a test sample. An example of a flow cytometer is the Fluorescence Activated Cell Sorter (FACScan) manufactured by Becton, Dickinson and Co, Franklin Lakes, N.J. In general, an imaging system contains an excitation source and a detection device. The excitation source excites the fluorescent signal generating group associated with the conjugate and the detection device detects the signal emitted from the excited signal generating group.
In a typical imaging system analysis, a test sample is incubated with a fluorescent conjugate, which specifically binds certain cells that may be present in the test sample. The incubation takes place for a time and at a temperature conducive for the binding of the conjugate to specific cell populations contained in the sample. The cells bound with the conjugate are commonly referred to as being stained and the staining procedure can be executed multiple times, sequentially or at the same time, with multiple conjugates, which emit signals of varying wavelengths. After the staining procedure is complete, the sample can be analyzed using a flow cytometer.
In an alternative embodiment, a conjugate comprising the dyes described herein can be adapted for use in conventional solid phase immunoassays such as, for example, a sandwich type immunoassay. A sandwich type immunoassay typically involves contacting a test sample suspected of containing an analyte with a substantially solid inert plastic, latex or glass bead or microparticle, or other support material which has been coated with a specific binding member that forms a binding pair with the analyte. The binding member-coated support material is commonly referred to as a xe2x80x9ccapture reagentxe2x80x9d. After the analyte is bound to the support material, the remaining test sample is removed from the support material. The support material, to which the analyte is bound, is treated with a conjugate, which generally comprises a second binding member labeled with a signal-generating group. The conjugate becomes bound to the analyte, which is bound to the support material. The combination of support material having the first binding member, the analyte, and the conjugate bound thereon is separated from any unbound conjugate, typically with one or more wash steps. The signal generated by the signal generating group, through appropriate excitation, can then be observed visually, or more preferably by an instrument, to indicate the presence or amount of an analyte in a test sample. It will be understood, of course, that the order and number of the steps employed to perform such assays are not intended to limit the invention described herein.
The analyte detected by such an immunoassay can be the product or products of an amplification reaction. Accordingly, the analytes can comprise nucleic acid sequences or can be otherwise the products of a hybridization reaction such as LCR, which is described in European Patent Applications EP-A-320 308 and EP-A-439 182, and PCR, which is described in U.S. Pat. No. 4,683,202 and 4,683,195, all of which are incorporated herein by reference. In cases where the analytes comprise, for example, LCR or PCR reaction products or sequences, the sequences can comprise or be modified to comprise a binding member that forms a binding pair with an indicator reagent and a binding member that forms a binding pair with a capture reagent.
The use of reticulocytes stained with the dyes described herein in a flow cytometer is particularly advantageous in that there are low fluorescent backgrounds, and fluorescent gates may be easily selected by use of an unstained control. Moreover, because there is no precipitation of intracellular reticulocyte RNA, whereby the cells need not be fixed. In addition, the relationship between the fluorescent signal and the individual reticulocytes provides information as to the age of the reticulocytes.
Still another advantage of the prevent invention is that reticulocytes stained with the dyes described herein can be used in an automated flow cytometer having lower light intensity, e.g., one may use a helium-neon laser as opposed to an argon laser.

Helium-neon excitable reticulocyte dyes derivable from halolepidines

Abstract: wherein: R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, Y, and n are as defined in the specification.


A device is provided for releasing a spear shaft of a spear gun for scuba diving or the like. The shaft has a latch element formed on a first lever pivotally connected at its front end to a screw attached to and integrally with a frame of the gun, the lever being maintained elastically in a resting position. The gun has a trigger with an abutment portion forced elastically against the front end of the first lever extending forward of a convex upper surface. The convex upper surface intersects a concave surface at an edge that traces a first circular trajectory when the trigger is rotated. A second lever is rotatably connected to the frame, the front end of the second lever being movable along a second circular trajectory intersecting the first circular trajectory. An arm of the second lever extends so as to intersect the trajectory of the spear shaft when it is loaded in the gun, such that the shaft abuts the latch element first, thereby moving the first lever away from its resting position, until it engages a shaped cavity of the shaft, and subsequently abuts the arm of the second lever. This causes the second lever to turn until it abuts the first lever in line with the latch element, simultaneously raising its front end up to and against the convex surface of the trigger. The front end of the first lever is slidingly connected to a screw, such that the first lever may be variably displaced, thereby adjusting the force applied by the second lever to the trigger.

Conventional spear guns, such as those utilized in scuba diving, typically comprise a frame having a longitudinally elongated body mounting, at a rear end, a grip and a trigger. A shaft of a spear is mounted to a front end of the frame, the shaft being mounted slidingly on the elongated body of the frame. The spear is then launched toward a desired target, e.g., a fish, by pulling the trigger. The rear end of the shaft is usually connected to a string line for retrieval of the spear and any prey that may have been snagged by the diver.
The force for propelling the spear is provided by a pair of cables, made of an elastic material, that are stretched and hooked to the shaft of the spear when the diver loads the gun. Once the trigger is pulled, the spear is released, effecting conversion of the elastic energy accumulated by the elastic cables into kinetic energy in the spear shaft, and propelling the spear outwardly along the longitudinal axis of the gun.
The kinematic trigger mechanism that enables the diver to launch or shoot the spear generally comprises a lever hingedly mounted to the frame with a latch element at one end for engaging a notch at a proximal end of the spear's shaft when the spear is loaded on the gun so as to withstand a pulling force exerted on the shaft by the elastic cables. During loading, the proximal end of the shaft abuts a radial appendage on the lever, thereby inducing its rotation, Such rotation results not only in engagement of the latch member with the notch on the shaft, but also of the opposite end of the lever elastically within a seat in the trigger formed on the side opposite its operating arm. Disengagement of the lever from the trigger, induced when a diver's finger pulls on the operating arm, causes the shaft to be released from the latch element and the propulsive force of the elastic cables prevails.
The kinematic chains often used to operate spear guns, though useful, do not permit adjustment of the stroke of the trigger nor of the force necessary to pull it. If the stroke of the trigger is short, and the spear gun is operated by an inexperienced scuba diver who lacks a feel for the trigger, or in the event of other circumstances such as a diver's use of very thick gloves, the spear may be accidentally released. Simply put, adjustments of the trigger's stroke and/or graduating the effort required for a diver to pull the trigger has been found difficult and has yet to provide a solution that is both safe and simple.

Device for releasing a spear shaft of a spear gun for scuba diving or the like


A sensor arrangement detects an angle of an actuator which is rotationally arranged on a support. The arrangement includes a first sensor element and a second sensor element. The first sensor element can be coupled to the actuator in order carry out a movement with respect to the support in accordance with a rotation of the actuator. The second sensor element can be rotationally fixed on the support and can be coupled to the first sensor element in order to produce, when rotating the actuator and a thus resulting movement between the first sensor element and the second sensor element, a sensor signal which is dependent on the rotation carried out by the actuator.

The present invention relates to a sensor arrangement for angle detection in a manual transmission and, in particular, to a sensor arrangement for sensing a tilt fork of a manual transmission, in particular of a utility vehicle.
Utility vehicle designs (e.g. for utility vehicles in local transportation and long-distance transportation, distribution transportation as well as for overland transportation and coach transportation) frequently have manual transmissions with a plurality of gears which are manufactured with a group construction method. In utility vehicles, this design is being increasingly used for automated manual transmissions, wherein theoretically different degrees of automation can be carried out. Depending on the embodiment, the starting process, the activation of the clutch and the gear selection, can be carried out automatically in this context. In the case of manual transmissions, none of these processes is automated. In partially automated manual transmissions, at least one of these processes is automated, and in fully automatic shift operations, all the processes are carried out in an automated fashion.
Therefore, there is a need for adapted activation devices for an automated starter clutch, automated coupling during shifting, and automated gear selection during a motor management process. The most precise sensing of the positions of shift elements is of essential importance for shift automation, in order as a result to optimize further automated shift sequences and to increase the efficiency.
In known conventional systems, the positions of shift elements in manual transmissions are determined by sensing linear displacements. Such displacements represent, for example, a desired actuator travel (for example, for a shift fork) and can be sensed, for example, by use of a piston position within a cylinder.
In an automated manual transmission, angular settings are sensed by one or more tilt forks and are passed on to a transmission control unit (TCU). It is important in this context to determine the position of the tilt fork (or forks) as precisely as possible and to reduce inaccuracies in the measurement chain. Such inaccuracies occur, for example, as a result of wear, as a result of play, elasticities owing to rigidities, and thermal expansion.
Therefore, there is a need for a sensor arrangement which does not have the abovementioned disadvantages or limitations.
This technical problem is solved by a sensor arrangement and a manual transmission in accordance with embodiments of the invention.
The present invention provides a sensor arrangement which is suitable for sensing angles of a rotatable actuator relative to a mount, wherein the actuator is rotatably arranged on the mount. The sensor arrangement comprises (at least) one first sensor element and (at least) one second sensor element. The first sensor element can be coupled to the actuator in order to carry out a movement (e.g. a rotation) relative to the mount in response to a rotation of the actuator. The second sensor element can be secured in a rotationally fixed fashion to the mount and can be coupled to the first sensor element, in order to generate a sensor signal when the actuator rotates and there is a resulting relative movement (e.g. rotation) between the first sensor element and the second sensor element, which sensor signal depends on the rotation carried out by the actuator.
The actuator and the mount do not need to be part of the sensor arrangement. The actuator can be, for example, a shift fork of a manual transmission to which the sensor arrangement can be attached. Within the scope of the present invention, the term sensor signal is to be interpreted as broadly as possible and can comprise any desired change in the electrical current/or the voltage which changes on the basis of the movement. This change can be caused by a change in resistance along a current path or an inductive change or a change which is caused by Lorentz force. However, it can also be an optical signal which changes in a movement-induced fashion.
Exemplary embodiments of the invention solve the abovementioned technical problem by means of a sensor arrangement for directly sensing a rotation of at least one actuator of a transmission shift system.
In particular, a magnetic measuring principle can be used. For example, the first sensor element comprises a permanent magnet which generates a variable magnetic field with a rotation of the actuator, and the second sensor element is designed to generate the sensor signal in response to a change in the magnetic field.
In further exemplary embodiments, the sensor arrangement comprises an evaluation circuit and a housing. The second sensor element and the evaluation circuit can optionally be secured together with the housing on the mount (e.g. has an enclosed, encapsulated unit).
In further exemplary embodiments, the first sensor element and the second sensor element are part of an inductive or magnetic sensor which can have, for example, a (2-dimensional or 3-dimensional) Hall sensor or a magnetoresistive sensor. The magnetoresistive sensor can be, for example, a GMR (giant magnetoresistance) sensor, an AMR (anisotropic magnetoresistance) sensor, or a TMR (tunnel magnetoresistance) sensor.
The present invention is, however, not limited to a magnetic measuring principle. For example, in further exemplary embodiments the first sensor element and the second sensor element are coupled optically to one another, wherein the sensor element comprises a light source (e.g. a laser), a light sensor and geometric structures (e.g. slits) which interrupt the light signal as a function of the relative rotation.
In further exemplary embodiments, the sensor arrangement optionally comprises a transmission which couples the first sensor element to the actuator. It is therefore possible to convert a rotational angle range of the actuator to a relatively large angular range of the first sensor element, in order thereby to permit a relatively large angular resolution.
In further exemplary embodiments, the first sensor element is secured directly in a rotationally fixed fashion to the actuator without a coupling element such as, for example, a transmission.
In further exemplary embodiments, the sensor arrangement also comprises a temperature sensor for sensing a temperature in order to carry out a correction on the basis of the sensed temperature. The temperature sensor can be embodied as a separate component or can also be integrated in a chip. The sensing of the temperature is important, for example, in order to execute a shift process in a transmission in an optimal way. Apart from temperature-induced expansion, the consistency of a gear oil is also dependent on the temperature. The transmission controller can take these data into account and can evaluate a sensed rotational angle differently as a function of the temperature.
The present invention also relates to a sensor system which can be coupled to a control unit. The sensor system comprises (at least) one first sensor arrangement and (at least) one second sensor arrangement, such as have been defined above. Furthermore, the sensor system comprises a bus system which is designed to transmit data between the first and second sensor arrangements and the control unit. For this purpose, for example a universal interface can be used which can be employed for a plurality of sensors. Exemplary embodiments can therefore be adapted to various shifting concepts.
The present invention is also related to a manual transmission with a sensor arrangement or a sensor system such as have been defined above, and to a control unit. The actuator can optionally be a shift fork, and the control unit can be designed to control shifting of the manual transmission and to evaluate sensor signals of the sensor arrangement. The control unit can indicate, in particular, a shifted state of the manual transmission.
In further exemplary embodiments, the manual transmission comprises a further sensor which is designed to detect a movement of the shift fork, with the result that the further sensor and the sensor arrangement are redundant, in order to satisfy safety-relevant requirements.
In further exemplary embodiments, the manual transmission comprises a control unit which is designed to convert the sensed rotary sensor signal (which indicates a rotational angle) into a distance or a linear movement and in this way detect the position of a shift fork in the transmission. The conversion can be defined by way of a corresponding calibration in which a sensed rotational angle is assigned to a linear offset which ultimately brings about the shift process. This assignment can change over time, for example as a result of wear. This can be compensated by a software-based learning process. Furthermore, this assignment can also depend on the temperature (e.g. owing to thermal expansion), with the result that the sensed temperature can optionally be taken into account for this. Thus, different shifting concepts can easily be implemented.
The present invention also relates to a control device for a manual transmission of a utility vehicle, wherein the control device can comprise the sensor arrangement or can at least receive sensor signals from the sensor arrangement, in order to control the manual transmission on the basis of the sensed sensor signals and to activate actuators correspondingly.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

Sensor arrangement for angle detection and manual transmission

KNORR-BREMSE Systeme fuer Nutzfahrzeuge GmbH


The present disclosure provides a bird feeder moveable from a first position to a second position. The bird feeder is preferably comprised of a seed tube for holding a substance, a seed tray having openings to receive and provide access to the substance, a shroud surrounding and protecting both the seed tube and seed tray and a cover secured to an upper end of the shroud. The bird feeder is also preferably comprised of a positioning mechanism to move the bird feeder from the first position, where access to the substance is provided, and the second position, where access to the substance is prevented.

Bird feeders have been around for quite some time for bird watchers and animal lovers. However, many problems exist with current bird feeders, including but not limited to water or other moisture accumulating into the feeder and poor ventilation unable to properly dry the feed.
Further, many bird feeders are comprised of bulky singular elements that are difficult to take apart for cleaning, which is necessary to provide clean feed for birds.
Devices such as U.S. Pat. No. 7,191,731 have attempted to overcome some of the problems by providing shrouds to reduce wear on the feed tubes, the shrouds moveable from a position to another to allow or prevent access to feed. However, such devices are more difficult to take apart and clean, and do not provide the requisite ventilation necessary for the seeds to remain fresh.
As such, there is a need for a novel type of bird feeder that can overcome the problems of the prior art.


The present invention provides a method for producing a high-quality capillary tube used in an electrophoresis apparatus in a safe and inexpensive manner. A polymer coating on a capillary tube is converted into gas and removed through an oxidative reaction with oxygen radicals resulting from ozone decomposition.

Electrophoresis apparatuses that utilize capillary tubes for rapid processing of mass data are widely used in DNA nucleotide sequence analyses. The capillary tubes used are generally glass tubes having an inner diameter of 1 to 800 μm, an outer diameter of 50 to 1,000 μm and a length of 50 to 2,000 mm, which is coated with a polymer to a thickness of 10 to 30 μm, among which a capillary tube of an appropriate size is employed. Polymer, generally polyimide, is coated to enhance the mechanical strength and give flexibility to the fragile glass tube for easy handling. However, since a sample migrating inside a capillary tube is detected by irradiating the fluorescence-labeled sample with a laser beam from outside the capillary tube and detecting the excited fluorescence, a polymer coating with a poor light transmittance will interfere with the sample detection. Thus, it is necessary to selectively remove the polymer coating for a length of about 1 to 20 mm around the periphery of the capillary tube. The portion removed of the polymer coating for an increased light transmittance is generally called a "window".
In order to process a window for a capillary tube, a technique in which a polymer coating is removed by burning with a lighter flame is generally employed when the number of capillary tubes is small. When the number of the capillary tubes is large, a technique such as one disclosed in JP-A-5-232085 may be employed in which a plurality of capillary tubes are supported at the same time to burn and remove predetermined regions of the polymer coating with a gas burner. However, burning with a lighter or a gas burner will leave cinders on the surfaces of the capillary tubes, and thus requires an after-treatment for wiping the cinders away with a wiper such as paper or cloth, which causes an increase in the production cost. Furthermore, wiping with the wiper may damage the exposed glass tube region. If the exposed glass tube region has a damage, the capillary tube can be susceptible to breakage during operations such as mounting the capillary tube on an apparatus. In addition, controlling the temperature of the flame is difficult since burning at a low temperature will leave a large amount of cinders and burning at a high temperature will result in deformation or poor transmittance of the glass capillary tube. Cinders on the window will interfere with the detection of fluorescence excited by laser irradiation.
In order to process a window by burning the polymer coating under a controlled temperature, techniques using an electric heater as disclosed in U.S. Pat. No. 4,940,883 (1990), JP-A-10-206383, JP-A-11-230939 may be employed. However, even under a controlled temperature, polymer coating is difficult to be burnt completely at or below an allowable continuous temperature of synthesized quartz (about 950° C.) that is generally used for making the glass tube, and a border between regions heated and unheated by the electric heater always includes insufficiently heated parts. As a result, after-treatment for wiping away the cinders is inevitable. Even if the window is elegantly processed, remaining cinders may fall off after the capillary tube is mounted on the electrophoresis apparatus, and may stick to a part that may cause an adverse effect on detection.
As a processing technique other than burning, JP-A-6-74938 discloses a technique for mechanically removing the coating with a scraper. However, it is difficult to remove the coating efficiently without damaging the glass tube. According to another technique, the polymer coating will be sublimed through ablation with an excimer laser. However, this technique requires an expensive device and a large installation area. Reagents such as hot sulfuric acid and hydrazine may be used for removing the coating. However, they are hazardous and thus have drawbacks such as difficult handling, requirement of after-treatment, requirement of waste fluid processing and a risk of causing adverse effect on the environment. Above all, since they are liquid, it is difficult to provide a mask for exposing only a region to be processed into the window to immerse the tube in the drug.
A capillary tube provided with a window is susceptible to breakage because stresses caused upon bending or pulling the capillary tube may concentrate on the damage of the exposed glass region. The polymer coating is provided basically to enhance the mechanical strength and flexibility of the glass tube. Another reason for easy breakage of the capillary tube by the concentration of the stresses on the exposed portion is the profile of the edge of the coating at the window. When the edge of the coating at the window is removed generally perpendicular to the longitudinal direction of the capillary tube, the stresses will be concentrated on the edge of the coating at the window upon bending the tube and cause easy breakage.
In a multi-capillary electrophoresis apparatus, a plurality of capillary tubes are used as a multi-capillary array with the windows arranged in parallel to form a plane with the ends of the tubes being aligned. The windows of the multi-capillary array are supported by a holder so that the tubes are held secure. Capillary tubes having windows are used to produce the multi-capillary array. Since the mechanical strength of the glass capillary tubes with exposed windows is poor, they are difficult to be handled upon assembly, which interferes with automation of producing a multi-capillary array.
The above-described conventional techniques have adverse effects on the strength and the measurement due to damage, deformation, poor transmittance or the like of a glass capillary tubes and have the following problems: requirement of an after-treatment following the coating removal; requirement of an expensive device and a large installation area for the device; or use of a reagent that may be hazardous to human and the environment. In addition, conventional techniques have a problem of being susceptible to breakage which is caused by concentration of stresses on the edge of the coating at the window of the capillary tube, and a problem of automation in assembling fragile capillary tubes having windows being impossible for producing a multi-capillary array.
The present invention has an objective of providing a tough capillary tube provided with a window, which is produced in a safe and inexpensive manner by a method that causes no adverse effect, such as damage, deformation, poor transmittance or the like on a glass tube as a main body of the capillary tube, which may interfere with optical detection of a sample by an electrophoresis apparatus and while saving trouble such as wiping after the coating removal. The present invention also has an objective of providing means for automating production of a multi-capillary array, which has been impossible.

This patent is subject to a terminal disclaimer.

Removal method for coating of polymer coated glass capillary tubing and polymer coated glass capillary tubing


A sampling device for analysis of a substance which is chosen from the group consisting of isocyanates, aminoisocyanates, amines, and isothiocyanates, and which is present in an air flow intended to pass through the sampling device is disclosed, as well as a method for the production of said sampling device, and a method for the analysis of said substance in the air flow.

Polyurethane (PUR) products frequently occur in industry, in particular in manufacturing and handling polyurethane foam, elastomers, adhesives and lacquers. Polyurethane is produced by the reaction of a bifunctional isocyanate with a polyfunctional alcohol. The satisfactory technical qualities of polyurethane have resulted in a large increase of its use and application fields during the last decade. In connection with thermal decomposition of polyurethanes, however, the formation of isocyanates, aminoisocyanates and amines might occur, and extremely high contents can be found in air, e.g. when welding automobile sheet steel. Besides the known types of isocyanate, also new types of aliphatic isocyanates have been detected, in connection with e.g. heat treatment of car paint. Most of the isocyanates formed have been found to be represented by so-called low molecular isocyanates. During short periods of heating, as is the case when welding, particularly high contents of isocyanates may be present (peak exposure). Of all the dangerous substances on the limit value list, isocyanates have the lowest permissible contents. Exposure to this new type of isocyanates was previously unheard of. Isocyanates in both gas and particle phase have been detected in connection with welding, grinding and cutting of painted automobile sheet steel, and respirable particles in high contents containing isocyanates have been detected. In thermal decomposition products of painted automobile sheet steel, detection has been made of, among other things, methyl isocyanate (MIC), ethyl isocyanate (EIC), propyl isocyanate (PIC), phenyl isocyanate (Phi), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,4- and 2,6-diisocyanate toluene (TDI) and 4,4-methylene diphenyldiisocyanate (MDI).
In thermal decomposition of phenol/formaldehyde/urea (FFU) plastic, isocyanic acid and methyl isocyanate are formed. FFU plastic is used, among other things, in wood glue and as a binder in mineral wool (and bakelite), which is frequently used as insulation for ovens and furnaces in industrial and domestic use. New fields of application in which exposure to isocyanates has been detected are the soldering and processing of printed circuit boards in the electronic industry, the welding, grinding and cutting of painted sheet steel in the automobile industry and the welding of lacquered copper pipes. Isocyanates have a varying degree of toxicity to the organism depending on their chemical and physical form. As a result, the hygienic limit values have been set at an extremely low level in all countries. For the exposed individual, the degree of exposure to isocyanates varies considerably in different operations during a working day and in connection with breakdowns. Thermal decomposition products from PUR constitute a special problem, since new and completely unknown isocyanates are formed, whose toxicity has not yet been analyzed in a satisfactory manner. Furthermore, the increasingly sophisticated measuring methods have revealed exposure to isocyanates in an increasing number of operations in industry.
To sum up, there are a number of operations in numerous working areas where people are daily exposed to or at risk being exposed to isocyanates at a varying degree. Considering the ominous tendency of isocyanates to cause respiratory diseases and the fact that there are some carcinogenic substances among the thermal decomposition products of polyurethane, e.g. 2,4-diamine toluene (TDA), 4,4-methylene diamine (MDA) and MOCA, it is very important to measure in a reliable, sensitive and rapid manner any presence of isocyanates, but also other decomposition products dangerous to health, in environments where there is such a risk.
Several commercially available direct reading instruments for isocyanates and other reactive organic and inorganic compounds are known. One type is based on a principle where e.g. air containing isocyanates is sucked through a cellulose filter paper. The filter paper (filter-tape) is impregnated with reagents. The result of the reaction between e.g. isocyanates and the reagents is that a color is formed (see references 1-7). The intensity of the color depends on the air concentration of e.g. isocyanates.
The measuring principle is based on a light source emitting light (of a certain wave length) to the impregnated filter tape. Then a detector measures the reflected light. The color formation with time on the impregnated filter is proportional with the air concentration of e.g. isocyanates. Such commercially available instruments are either static or dynamic. In the static instruments the impregnated filter is put on in the measuring device and the air concentration can be measured either by visual observation by comparison with a colored reference. In the dynamic measuring devices the tape is static for a certain period of time (typically 2 minutes) and thereafter the filter is moved and a new fresh filter is placed in the sucking zone.
These instruments typically provide continuous air monitoring of e.g. isocyanates and the air concentration can be instantaneously monitored. The measuring devices can be hand held or stationary. The measuring device needs to be calibrated for the compound that is to be measured. There may be interferences if several compounds are present in air.
Drawback with Current Techniques:
There are several drawbacks with the present types of instruments. One major drawback is that the response may vary if the compounds to be measured are present in particle form. Gas phase compounds will form a homogeneous color over the sampling spot on the filter whereas compounds in particle form will have a non homogenous color on the filter. Particles will create spots of more intense color on the filter. In addition droplets (particles) will impact on the filter resulting in incomplete reaction between the compounds to be measured and the reagent as the reagent and the compounds in the particles will not efficiently mix. The air levels will be underestimated. In fact, the principle does not correctly work for particle borne compounds.
The measurements of compounds in gas phase are basically more relevant, but still considerable limitations are present. If the air contains particles (such as soot and smoke) the particles will deposit on the filter. The measuring principle has the drawback that reflected light will be affected also by other compounds/particles that are deposited on the filter. Further, some isocyanates in the gas phase, such as methyl isocyanate (CH3NCO) and isocyanic acid (HNCO), will pass through the filter (breakthrough) and will therefore not react with the reagent and form a color and will not be detected (see references 1 and 2). Another drawback is that the color reaction will not only take place on the surface of the filter but also on deeper layers (and the backside) but it is only the color on the surface that is measured (detection losses). In addition, the reaction depends on the air humidity. If the air is very dry, the formation of color will be slow and much less color is formed as compared to humid air. Sufficient air humidity is critical for correct estimation of air concentration (see reference 1). The color formed for low molecular weight isocyanates with the old technique is not permanent which results in an unsatisfactory low sensitivity.
Further, it would be of interest to detect smaller hazardous compounds, e.g. smaller isocyanates, in a reliable and also quicker way than hereto known.
In view of this, there is a great demand for an improved sampling device and an improved method for sampling of products dangerous to health, such as isocyanates, aminoisocyanates, amines, and isothiocyanates, in a rapid, reliable, precise and tamper proof manner.


A measuring cell for a gas analysis spectrometer has an inner chamber for a sample gas to be analyzed and an inlet and an outlet which are connected thereto. A traversing optical path for a measuring beam is formed in the inner chamber. The measuring cell is tubular, the inlet and the outlet are arranged at opposite ends, and the inner chamber of the measuring cell has a cross-sectional shape that is monotonic over the length of the tube and which has an oval-shape at the start, which disappears toward the end. That special shape results in fast gas exchange and thus high dynamics, even with larger measuring cells, which have high sensitivity due to the long optical paths thereof. Two characteristics which until now appeared to be conflicting are thereby combined.

The invention concerns a measuring cell for a gas analysis spectrometer with an inner chamber for a gas to be analyzed, an inlet and an outlet, wherein a traversing optical path for a measuring beam is formed in the inner chamber.
The optical analysis of gases is applied widely in various areas of technology. Special requirements are demanded by exhaust gas measurement applications for internal-combustion engines. Due to increasingly strict exhaust gas regulations, not only is a high level of sensitivity required to achieve a low detection threshold, but also a high time resolution to ensure a sufficiently good dynamic response of the measurement, in particular, with respect to non-stationary operating states of internal-combustion engines. This results in a conflict of objectives between detection sensitivity and the time resolution of the system. In such measuring cells for optical gas analysis devices, the detection sensitivity depends on the optical path length that the measuring beam travels through the gas to be analyzed in the measuring cell. This path length, in turn, depends on the inner chamber volume of the measuring cell and the guidance of the measuring beam. However, the time resolution that is decisive for the dynamic response directly depends on the time needed to replace the gas to be analyzed in the measuring cell. It is important that the gas is replaced in its entirety. Increasing the volume of the measuring cell therefore has the disadvantage that, while other parameters remain constant, the time required to completely replace the gas increases, causing the time resolution and therefore the dynamic response to decrease correspondingly.
Various approaches for increasing the quality of the measurement are known from prior art. In many measuring cells, attempts are made to increase the detection sensitivity for a constant cell volume by optimizing the optical path. U.S. Pat. No. 5,440,143 A1 describes attaching a special mirror system onto an otherwise standard measuring cell with a square cross-section, which produces a multiply folded and therefore extended optical path for the measuring beam. Disposing multiple measuring cells one behind the other so that the measuring beam is first guided through a first measuring cell and then through another, is known from US 2007/0182965 AI. A universal measuring cell for adapting the length of the optical path is known from JP 10/062335 A, wherein the cell is constituted as two telescopic partial bodies.
An alternative approach has tried to influence the flow of sample gas within the measuring cell (DE 103 18 786 A). In such a measuring cell, however, relatively large "dead zones" are formed, which increase the exchange time and worsen the dynamic response. As FIG. 7 schematically shows, in a measuring cell (9) according to prior art, swirling (91) of sample gas in the measuring cell causes formation of dead zones in which molecules of the sample gas can dwell for a comparatively long time, preventing fast exchange. As the concentration of the supplied sample gas (90) changes, the previous concentration is still partly present so that the new concentration value can only be correctly determined once the gas in the dead zones has also been exchanged.
The resulting time delay causes carryover (concentration carryover), which in turn results in a long response time of the measuring cell and therefore of the entire measuring system.
The object of the invention is to create an improved measuring cell with a better dynamic response.

Gas cell for the optical analysis of gases


A system for the compression and decompression of sections of audio files is provided. A library of basic waveforms is produced by applying selected digital initialization codes to a chaotic system. Each basic waveform is in one-to-one correspondence with an initialization code. A weighted sum of the selected basic waveforms is used to approximate a section of audio file. The basic waveforms are then discarded and only the weighting factors and the corresponding initialization codes are stored in a compressed audio file. When the compressed audio file is decompressed for playback, the stored initialization codes are stripped out and applied to a similar chaotic system to regenerate the basic waveforms, which are recombined according to the stored weighting factors to reproduce the original section of audio file.

In general, a chaotic system is a dynamical system which has no periodicity and the final state of which depends so sensitively on the system's precise initial state that its time-dependent path is, in effect, long-term unpredictable even though it is deterministic.
One approach to chaotic communication, Short, et al., Method and Apparatus for Secure Digital Chaotic Communication, U.S. patent application Ser. No. 09/436,910 ("Short I"), describes a chaotic system controlled by a transmitter/encoder and an identical chaotic system controlled by a receiver/decoder. Communication is divided into two steps: initialization and transmission. The initialization step uses a series of controls to drive the identical chaotic systems in the transmitter/encoder and receiver/decoder into the same periodic state. This is achieved by repeatedly sending a digital initialization code to each chaotic system, driving each of them onto a known periodic orbit and stabilizing the otherwise unstable periodic orbit. The necessary initialization code contains less than 16 bits of information. The transmission step then uses a similar series of controls to steer the trajectories of the periodic orbits to regions of space that are labeled 0 and 1, corresponding to the plain text of a digital message.
Short, et al., Method and Apparatus for Compressed Chaotic Music Synthesis, U.S. patent application Ser. No. 09/437,565 ("Short II"), describes the use of such an initialization step to produce and stabilize known periodic orbits on chaotic systems, which orbits are then converted into sounds that approximate traditional music notes. By sending a digital initialization code to a chaotic system, a periodic waveform can be produced that has a rich harmonic structure and sounds musical. The one-dimensional, periodic waveform needed for music applications is achieved by taking the x-, y-, or z-component (or a combination of them) of the periodic orbit over time as the chaotic system evolves. The periodic waveform represents an analog version of a sound, and by sampling the amplitude of the waveform over time, e.g., using audio standard PCM 16, one can produce a digital version of the sound. The harmonic structures of the periodic waveforms are sufficiently varied that they sound like a variety of musical instruments.
The present invention is a system for the compression and decompression of audio files, including without limitation music and speech files. In summary, a library of basic waveforms associated with a chaotic system is produced, according to Short II and as described in detail hereafter, by applying selected digital initialization codes to the chaotic system. The basic waveforms that can be produced with 16-bit initialization codes range from simple cases that resemble the sum of a few sine waves with an associated frequency spectrum containing only two or three harmonics, to extremely complex waveforms in which the number of significant harmonics is greater than 64. Importantly, the initialization codes are 16 bits regardless of whether the basic waveforms are simple or complex. By contrast, in a linear approach, one would expect the number of bits necessary to produce a waveform to be proportional to the number of harmonics in the waveform. Equally importantly, each initialization code is in one-to-one correspondence with a specific basic waveform, allowing the use of the corresponding initialization code to represent the basic waveform. Then basic waveforms selected from the library are used to approximate a section of audio file.
The basic waveforms that are most closely related to the section of audio file are selected, and a weighted sum of the selected waveforms is used to approximate the section of audio file. Once such a weighted sum is produced that approximates the section of audio file to a specified degree of accuracy, the basic waveforms can be discarded and only the weighting factors; the corresponding initialization codes; and certain frequency information described below are stored in a compressed audio file. The compressed audio file may also contain other implementation-dependent information, e.g. header information defining sampling rates, format, etc. When the compressed audio file is decompressed for playback, the initialization codes are stripped out and used to regenerate the basic waveforms, which are recombined according to the weighting factors in the compressed audio file to reproduce the original section of audio file.
The compressed audio file can be transmitted, or stored for later transmission, to an identical chaotic system for decompression at a remote location. In practice, the remote location does not need the compression part of the system and would only use the decompression part of the system if playback of the section of audio file is all that is desired.
A further degree of compression is often possible and desirable. After finding a suitable weighted sum of basic waveforms, the weighted sum can be examined and any waveforms that contribute less to the overall approximation than a specified threshold can be eliminated. When such waveforms are identified, the corresponding initialization codes can be removed from the compressed audio file. Also, because the compression is done on sections of audio file, it is possible to look at the basic waveforms and the corresponding initialization codes to determine if there is a predictable pattern to the changes in the weighting factors from section to section. If such patterns are detected, further compression of the compressed audio file can be achieved by storing only the requisite initialization code and information about the pattern of changes for the weighting factors.
It is an object of the present invention to create compressed music files for distribution over the Internet. Compression ratios at better than 50-to-1 may be possible, which will allow for the transmission of music files over the Internet with greatly improved download speed. It is possible to estimate the compression ratio for music based on how rapidly the music changes. These estimates indicate that if the music changes on a scale of 0.02 sec, so the important changes in the music occur 50 times a second, then compression of 60-to-1 should be achievable. If the music changes on a scale of 0.04 sec, compression of 120-to-1 should be achievable. It is also an object of the present invention to replace the standard MIDI technology used in the music industry with a system that is simpler, requires less memory and offers more flexible sampling requirements.
It is also an object of the present invention to produce compressed music files that decompress rapidly. For example, in one embodiment an unoptimized C++ program on a 300 MHz processor decompressed at better than three times faster than real time. In a more optimized version, decompression is better than 5 times faster than real time, running on a computer that is roughly equivalent to a 100 MHz processor.
It is yet another object of the present invention to create compressed audio files that are encrypted. For example, music files compressed with the present invention are naturally encrypted in accordance with Short I. In order to be able to decompress properly a compressed music file, it is necessary to have the proper chaotic decompressor. These decompressors could be distributed freely or to a group of registered users, thus allowing for some control over the distribution and reproduction of the compressed music files. Even greater control of the uses of the compressed music files can be achieved by incorporating a secondary layer of a secure chaotic distribution channel, using the technology described in Short I, to encode the digital bits of the compressed music files before transmitting them to a user. Since registered users can be given unique chaotic decoders, it will be possible to place a "security wrapper" around the compressed music files, so that only a registered user will be able to access the music. It will also be possible to structure the security wrapper so that a song can be played only once without paying a fee.

Method and apparatus for the compression and decompression of audio files using a chaotic system


In accordance with the objectives of the invention a new method is provided for the repair of an attenuated phase shifting mask having a contact pattern. The invention etches a single trench in the quartz substrate of the phase shifter mask and removes the impact of a void in the phase shifter material. Alternatively, the invention provides for first conventionally restoring the original dimensions of a contact hole in which a pinhole is present and then etching a single or a double trench in the exposed substrate of the restored contact opening.

(1) Field of the Invention
The invention relates to the fabrication of integrated circuit devices, and more particularly, to a method of creating an attenuated phase shifting mask by methods of repair thereof, whereby effects of pinholes are removed.
(2) Description of the Prior Art
During and for the fabrication of semiconductor devices optical projection tools are an integral part of the optical lithography technology that is fundamental to the creation of semiconductor devices and devices features. The optical projection tools conventionally contain an electromagnetic light source, a configuration of lenses and an optical projection mask that contains a replica of the image that is to be created. The image of the mask is, with the interference and the help of the configuration of lenses, projected onto the surface over which the image contained in the mask is to be created.
Semiconductor device improvements are traditionally and consistently achieved by sharp reductions in device feature dimensions, resulting in increasing device densities, which imposes on the supporting optical lithography technology the need for a continuing ability to provide images of smaller dimensions while maintaining image resolution.
Conventional photolithography masks are limited in this respect due to the increasingly smaller distance between adjacent light projections, which causes increased interference between closely spaced light projections. This has led to the development of phase-shifting masks, where effects of closeness of projecting light rays are cancelled by controlling the relative phase relationship between closely adjacent rays of light.
A phase shifting mask is provided with a layer of phase shifter material that is created in a pattern over the substrate of the mask. The patterned layer of phase shifter material causes the light that passes through the layer of phase shifter material to be out-of-phase by 180° with respect to the light that passes through the substrate over which the patterned layer of phase shifter material has been created. This results in a corrective action between the light that passes through the transparent substrate of the phase shifter mask and the light that passes through the layer of phase shifter material, this corrective action allowing further reductions in the images that are created using the phase shifter mask. Optionally, a phase shifter mask may also be provided with a patterned layer of opaque material such as chrome to further enhance the mask application.
Phase shifting masks are generally created using methods of photolithography. These methods at times lead to the introduction of fabrication defects in the surfaces of the created mask. For a phase shifter mask to be operational, especially considering the deep-submicron device features that must be created using the phase shifter mask, surface irregularities, such as voids occurring in a layer of phase shifter material, must be prevented or corrected if present. Any surface irregularity that occurs in any of the layers of the phase shifter mask, including the substrate of the phase shifter mask, results in a disruption of the there-through transmitted light and therefore in an interruption of a coherent interaction between the phase controlled light that is transmitted through the phase shifter mask.
Cost considerations relating to the creation of phase shifter masks lead to the need for repairing phase shifter masks that show any defects that may negatively affect the desired performance characteristics of the phase shifter mask. The invention addresses this concern and provides a method for the repair of attenuated phase shifter masks with a contact pattern.
U.S. Pat. No. 6,159,641 (Baume et al.) shows a method for repairing masks.
U.S. Pat. No. 6,016,357 (Neary et al.) discloses a method to repair PSMS.
U.S. Pat. No. 6,114,073(Yang) shows a method to repair PSMS.
U.S. Pat. No. 5,272,024 (Lin) discloses a structure and method for PSM repair.
U.S. Pat. No. 6,361,904 B1 (Chiu) shows a method for repairing the Shifter Layer of an alternating phase shifter mask.

Single trench repair method with etched quartz for attenuated phase shifting mask

Taiwan Semiconductor Manufacturing Co., Ltd.


A power-saving scissors comprises a first handle having a first knife set; the first handle being formed with a receiving space; an inner wall of the receiving space being formed with teeth; a second handle pivotally installed to the first handle by a planet gear set; the second handle having a second knife set; a center gear being protruded from the second handle at a position corresponding to the receiving space; the center gear being engagable with the receiving space of the first handle; the planet gear set including the center gear, three peripheral gears and a cover; one end of the center gear being installed to the second handle and another end thereof being protruded with a post; the three peripheral gear being respectively engaged to the center gear and also engaged to the teeth of the receiving space.

The prior art scissors have two handles, which are pivotal installed to each other. By rotating one handle, the other handle will rotate with respect to the handle. If it is desired to cut a hard object, the user must apply a great force to the handle. There is no mechanism which can make the user apply less force to the scissors.


In one aspect of the teachings herein, an interface circuit obviates the need for a microcontroller with multi-channel PWM capability in the context of controlling a brushless, three-phase DC motor. Instead, the interface circuit generates the requisite set of motor-phase control signals using a single PWM channel from the microcontroller. The interface circuit is implemented as a standalone integrated circuit (IC) in one embodiment, and is integrated into a pre-driver circuit in another embodiment.

FIG. 1 illustrates a microcontroller 10 that is configured for controlling a three-phase, brushless DC (BLDC) motor 12. A BLDC motor has a rotor with permanent magnets and a stator with windings, and is electronically commuted by energizing the stator windings in a pattern that rotates around the stator. The pattern—referred to as a rotating voltage vector—energizes two phases a time and induces opposing magnetic poles with respect to the rotor magnets, thereby inducing rotation. In the illustrated example, a drive circuit 14 provides the actual driving signals to the A, B, and C phases of the BLDC 12 and comprises three half-bridge transistor circuits that include a total of six transistors: Q1, Q2, Q3, Q4, Q5 and Q6.
The microcontroller 10 is specially adapted for driving the BLDC 12, based on its inclusion of a PWM module 16 having six PWM channels, PWM1-PWM6. The six channels correspond directly to the six transistors Q1-Q6 in the drive circuit 14, where Q1 is the high-side drive for the Phase A motor winding, Q2 is the low-side drive for the Phase A motor winding, Q3 is the high-side drive for the Phase B motor winding, Q4 is the low-side drive for the Phase B motor winding, Q5 is the high-side drive for the Phase C motor winding, and Q6 is the low-side drive for the Phase C motor winding.
The PWM1 signal is denoted as the AH′ signal to denote a logic-level signal as output from the microcontroller 10, and the corresponding gate-drive signal output from the pre-driver circuit 18 is denoted as AH. Similarly, the PWM2 and PWM3 signals are denoted as BH′ and CH′, respectively, and the pre-driver circuit 18 outputs the corresponding BH and CH gate-drive signals. In this regard, the pre-driver circuit 18 will be understood as converting the logic level signals output from the PWM module 16 of the microcontroller 10 into more robust—higher current—gate drive signals suitable for switching the transistors Q1-Q2 on and off.
The pre-driver circuit 18 also provides negative-logic inputs for the three PWM signals corresponding to the low-side transistors, for complementary PWM-based chopping of the transistors Q1-Q6. That is, the PWM4 signal is denoted as AL′ to indicate that it corresponds to the low-side drive transistor Q2, and the pre-driver circuit 18 outputs AL* as the complementary drive-level version of that signal. Likewise, PWM5 is denoted as BL′ and the pre-driver circuit 18 provides the corresponding complementary signal BL* for driving the low-side transistor Q4, and PWM6 is denoted as CL′ and the pre-driver circuit 18 provides the corresponding complementary signal CL* for driving the low-side transistor Q6.
With this arrangement, the microcontroller 10 energizes the A-B phases of the BLDC motor 12, for example, by outputting the same PWM signal on PWM1 (AH) and PWM4 (AL), and outputting a LOW signal on PWM5 (BL). With these signals and inversion by the pre-driver circuit 18, Q1 is chopped by the PWM signal output on PWM1, Q2 is chopped by the complementary version of that PWM signal, and the gate of Q4 is driven high (i.e., Q4 is turned on). As is known, the complementary chopping of Q1 and Q2 provide for motor speed control with current recirculation via the drive transistor body diodes.
Broadly, the microcontroller 10 controls the set of six PWM signals as motor phase control signals used to apply the aforementioned mentioned rotating voltage vector to the BLDC motor 12. According to such operation, the PWM signals sequentially energize phase pairs in the BLDC motor 12 according to the desired rotational direction and speed. FIG. 2 illustrates the correspondence between the PWM signal states and the corresponding motor-phase control states. Synchronous control of the BLDC motor 12 depends on knowing rotor position and, in the illustrated example, back-EMF (electromotive force) sensing is used to detect rotor position. Back-EMF sensing can be understood as a "sensorless" technique. Other position-sensing techniques rely on encoders or Hall effect sensors. In FIG. 1, the microcontroller 10 uses a general purpose input/output (GPIO) module 20 to obtain rotor position information.
While the foregoing control arrangement is well understood, it is not without certain disadvantages. For example, while the cost of microcontrollers has declined dramatically over the last several decades, they often still represent a significant fraction of the overall expense in a given motor-control circuit. In part this expense arises from the tendency for multi-channel PWM modules to be included only in more full-featured microcontroller families, thus obligating the designer oftentimes to design around a microcontroller that includes more sophistication and more features than are needed in the contemplated motor-control circuit.

Method and apparatus for brushless DC motor control