An apparatus for detecting biological deposits on the surface of a tooth. The device has illumination means to direct exciting radiation onto a test tooth surface and detection means to detect fluorescence emission from the test tooth surface at a wavelength associated with that of auto fluorescence emission from clean tooth surface. The intensity of the said fluorescence emission from the test tooth surface is compared with an intensity of auto fluorescence emission from clean tooth surface and the comparison is associated with the presence of deposits on the test tooth surface. The device is preferably embodied in a toothbrush which indicates to the user that deposits are present and are being removed.

This invention relates to a novel apparatus for the detection of biological deposits, in particular deposits of plaque, on the surfaces of teeth. In particular the invention relates to apparatus for this purpose which use fluorescence measurements to detect such deposits. In particular the invention relates to apparatus for this purpose which may be incorporated in a hand- or electrically operated toothbrush.
The term xe2x80x9cbiological depositsxe2x80x9d used herein refers generally to deposits of material of biological origin, e.g. plaque, bacteria, tartar, calculus etc. which are generally regarded as undesirable for dental hygiene. Dental plaque is a complex organic deposit generated in part by the activity of bacteria on the teeth or contamination, e.g. food deposits on the teeth, and is an undesirable precursor to tooth decay and the development of dental caries.
It is desirable to detect such deposits on the teeth before removing them, for example by toothbrushing, as detection indicates the areas at which dental cleaning effort should be concentrated. Such deposits can be difficult to detect in situ in vivo on the teeth. It is especially important to detect dental plaque. For detection of plaque it is known to use fluorescence measurement. In the state of the art there are two general methods for detecting dental plaque using fluorescence, secondary fluorescence and auto fluorescence. In secondary fluorescence teeth suspected of bearing plaque are treated with a fluorescent label material which preferentially binds to dental plaque, and after excess of the unbound material has been washed away from the teeth, the fluorescence emission, in response to illumination by exciting radiation, of the label material at areas of the tooth at which it has bound to plaque is detected to indicate the presence of dental plaque. WO 92/06671 and WO 25 97/01298 disclose typical methods based upon secondary fluorescence and apparatus which exploit such methods.
Auto fluorescence methods do not use a fluorescence label but instead detect the fluorescence emission from dental plaque itself in response to illumination by exciting radiation. U.S. Pat. No. 5,382,163, DE 29704185, DE 29705934, EP 0774235, and also WO 97/01298 disclose methods of this type and apparatus for performing these methods. Typically in these disclosures auto fluorescence emission by dental plaque at emission wavelengths above ca. 600 nm is detected and associated with the presence of dental plaque.
Optical methods are also known for the detection of dental caries, i.e. the tooth disease which can result from the non removal of plaque. Typical methods of this type are disclosed in for example U.S. Pat. No. 4,290,433, EP 0862897 and WO 97/42869, but these methods do not detect plaque deposits themselves.
These methods and apparatus disclosed in the state of the art for the detection of plaque have not proved to be optimum, especially when there is relatively little plaque presentxe2x80x94a state at which tooth cleaning is best carried out to remove early deposits of plaque before they can build up. Plaque deposits have different characteristics which vary from person to person, so it is desirable to provide a system which can be xe2x80x9cpersonalisedxe2x80x9d. Methods which require the application of fluorescent label materials to teeth are prima facie inconvenient.
It is therefore an object of this invention to provide an apparatus and a method for detecting biological deposits on teeth in vivo, which in part at least solves the problems of the state of the art.
According to a first aspect of this invention, an apparatus for detecting biological deposits on the surface of a tooth comprises;
illumination means to direct exciting radiation onto a test tooth surface,
detection means to detect fluorescence emission from the test tooth surface at a wavelength associated with that of auto fluorescence emission from a substantially biological deposit-free tooth surface,
means to make a comparison of the intensity of the said fluorescence emission from the test tooth surface with an intensity of auto fluorescence emission, at a wavelength associated with that of auto fluorescence emission from a substantially biological deposit free tooth surface, from a tooth surface known to have less biological deposit thereon than is present at the test tooth surface,
means to associate the comparison thus obtained with the presence of biological deposits on the test tooth surface, and,
indicator means to indicate the presence of such biological deposits to a user of the apparatus.
The test tooth surface may be any tooth surface in the user""s mouth which is believed or suspected to have a biological deposit such as plaque thereon, or which the user desires to test for the presence of plaque, usually with the intention of removing such deposits e.g. using a toothbrush.
For convenience a tooth surface known to have less biological deposit thereon than is present at the test tooth surface is termed hereafter a xe2x80x9ccleanxe2x80x9d tooth surface. A clean tooth surface may have biological deposit thereon but quantitatively less than is present at the test tooth surface, or preferably is free or substantially free of biological deposit.
The apparatus of this aspect of the invention is based upon the discovery that a tooth surface which is free of biological deposit, when illuminated with exciting radiation, emits a strong and easily detectable auto fluorescence emission, generally peaking in intensity at ca. 450 nm, but having a considerable intensity at higher wavelengths, and that this auto fluorescence emission is strongly attenuated by the presence of even small quantities of biological deposits such as dental plaque on the tooth surface, so that the intensity of this auto fluorescence is reduced if biological deposits are present on the tooth surface. It has also been discovered that this characteristic auto fluorescence is relatively unaffected by other features of the tooth surface, for example the colour or natural reflectivity of the teeth whether due to natural variations, age, sex, deposits from tobacco smoking etc. so that the apparatus and the method it employs are sufficiently unaffected by variations between the teeth of individual persons using the apparatus. Also the majority of commercial toothpastes are believed to emit no fluorescence in response to illumination by radiation which causes fluorescence emission from tooth surfaces or biological deposits thereon, and to differ in their spectra from natural enamel, so are not believed to interfere with the operation of the device of this invention.
Although for the purpose of exciting fluorescence a preferred wavelength for the exciting radiation is below 420 nm, radiation of this, short wavelength may in some circumstances be harmful to dental tissues. Consequently for safety reasons the exciting radiation is preferably at a wavelength 470xc2x140 nm. Suitable and preferred illumination means are discussed in more detail below.
A tooth surface free of biological deposits emits a fluorescence emission in the wavelength region above 420 nm, typically as shown in FIG. 1, peaking in intensity above ca. 450 nm. Therefore the detection means may detect the fluorescence emission at such wavelengths above 420 nm.
Suitably, inter alia to differentiate the exciting radiation from the fluorescence emission, the detector means detects fluorescence emission radiation at a wavelength of above 520 nm. At these wavelengths the auto fluorescence emission from the surface of teeth which are free or substantially free of biological deposits is still strong. It is preferred to measure the fluorescence emission radiation at a wavelength above ca. 530 nm, for example over the region 530-630 nm.
The means to make the comparison of the relative intensities of the auto fluorescence emission from the test tooth surface with that from a clean tooth surface may comprise an electronic signal/data processing system processing an electronic signal corresponding to the auto fluorescence emission. Preferably the system measures the area under the intensity/wavelength graph. Suitable signal/data processing systems which can do this are well known in the art.
The intensity of the auto fluorescence from a clean tooth surface may be determined in a number of ways.
In one construction of the device of this invention, the intensity of auto fluorescence emission from biological deposit-free or substantially biological deposit-free tooth surfaces may be treated as a constant for a given intensity of exciting radiation between individual persons as mentioned above. Such an intensity may be determined experimentally and may be stored as a reference standard in the apparatus as constructed and supplied to a user, e.g. in its electronics and/or software.
In an alternative construction the apparatus may be initially applied to a user""s tooth surface believed to be a clean tooth surface, e.g. the crown of a tooth, or a front, e.g. incisor tooth, which generally accumulate no or relatively little biological deposits such as dental plaque. In many cases such xe2x80x9ccleanxe2x80x9d surfaces can be considered as a substantially biological deposit-free tooth surface. The intensity of auto fluorescence emissions from a clean surface may be measured, and used as a basis for the comparison with the intensity of emission from the test tooth surface. After the apparatus has been first applied to a clean tooth surface of the user the apparatus may then subsequently is applied to the test tooth surface, and a comparison is made between the auto fluorescence measured at the clean tooth surface and at the test tooth surface.
In another alternative construction the detection means may be moveable between locations on the user""s teeth, e.g. across the surfaces of the user""s teeth, e.g. over a plurality or all of the user""s teeth, so that in the course of this movement the exciting radiation is directed onto a plurality of tooth surfaces on the same or different teeth. These surfaces are likely to differ in the quantity of biological deposits thereon, i.e. some surfaces having relatively less biological deposits thereon, to the extent that some such surfaces are xe2x80x9ccleanxe2x80x9d surfaces relative to the test tooth surface. For example the detection means may be moveable between regions on the base of the teeth and regions for example on the crowns of the teeth, or for example on front teeth, which as explained above are likely to be substantially free of biological deposits. This is termed a xe2x80x9cdynamicxe2x80x9d measurement, i.e. working by a movement of the device over the user""s teeth.
As the device of the invention in this construction is moved over the teeth surfaces of the user""s mouth it will encounter areas of test tooth surface where biological deposits are present, and also clean areas of the teeth. As a result the intensity of the fluorescence emission radiation detected by the detection device as it is moved around the mouth of the user over the tooth surfaces will vary between minima representing test tooth surfaces where there is a biological deposit, and maxima where there are clean tooth surfaces. Therefore the variation of fluorescence emission detected as the device moves around the user""s mouth is likely to show a series of intensity peaks and/or plateaus (hereinafter collectively referred to as xe2x80x9cpeaksxe2x80x9d) with time, and these peaks will show variation between regions of test tooth surface with biological deposit and clean tooth surfaces, relatively low peaks occurring at the former and relatively high peaks occurring at the latter. The difference in height between these relatively low and high peaks is representative of the difference in the amount of biological deposits of the test tooth surfaces. With the device of this construction it may be possible to detect the presence of biological deposits on a test tooth surface of a single tooth.
Alternatively by detecting the fluorescence emission peaks over a period of time during which the device moves over several teeth or all the user""s teeth, the presence of biological deposits on one or more test tooth surfaces may be detected. This can give a xe2x80x9cwhole mouthxe2x80x9d indication of the presence of deposit, i.e. showing the presence of deposits somewhere in the user""s mouth but possibly not giving a precise location on a specific tooth.
Additionally or alternatively the device may be adapted, e.g. by means of internal electronics and/or software to use pulse height analysis (a known technique) to measure the difference between highest and lowest peaks. Whilst this difference is changing, i.e. reducing, during a process of tooth cleaning e.g. brushing this indicates that deposits are present and are being removed, as more and more of the tooth surfaces become clean.
Additionally or alternatively the device may be adapted, e.g. again using pulse height analysis to measure the mean between highest and lowest peaks. Whilst this mean is increasing, as more and more of the tooth surfaces become clean, during a process of toothbrushing this indicates that deposits are present and are being removed.
There are also likely to be xe2x80x9cfalsexe2x80x9d minima of fluorescence emission where the illumination means is not directing the exciting radiation at tooth surfaces, and/or the detection means is/are not positioned to detect fluorescence emission from tooth surfaces. For example this may occur when the illumination means and/or detection means are aimed at or adjacent to gaps in the teeth, other parts of the mouth than teeth, or dental fillings etc. The device of the invention may be constructed to ignore such false minima, i.e. any fluorescence intensity peak below a specified certain value, e.g. responding only to intensity peaks within certain specified limits corresponding to the limits within which fluorescence emission from tooth surfaces is actually expected to occur.
Therefore according to this last described embodiment of the device of the invention, the detection means may be constructed to;
detect a fluorescence emission during a period of time over which the detection device moves from one tooth area to one or more other tooth areas;
detect peaks in the emission intensity with time;
and to measure and compare the heights of such peaks.
In particular in this embodiment the device may be constructed to measure the difference between the height of the lowest and the highest of such peaks, and to associate this difference with the presence of biological deposits which are then indicated to the user. For example a difference of 5-90% may occur, e.g. 5-50%. Alternatively or additionally in this embodiment the device may be constructed to measure the difference between the height of the lowest and the highest of such peaks, to then calculate the mean, and to associate an increase in this mean with the presence of biological deposits which are then indicated to the user. Typically an increase in the mean of 5-90% may occur, e.g. 5-50%.
The detection of such peaks of fluorescence emission intensity, and the measurement and comparison of the peak heights is easily within the ability of modern detection, electronic and data processing systems.
In another alternative construction the device of the invention may be provided with detection means to detect fluorescence emission from two spaced apart regions of tooth surface, and to compare the relative intensities of fluorescence emission from these two spaced apart surfaces, to associate any such difference with the presence of biological deposits on the tooth surface and indicate the presence of such deposits to the user.
If the distance the two regions are spaced apart is appropriate it will be likely that if one of the regions has biological deposit thereon the other will be a clean region. A suitable maximum spacing apart of the two regions may be up to the height, i.e. the distance from the junction with the gum (i.e. the gingival margin) to the crown of the tooth. Typically the spacing apart of these two regions may therefore be from ca. 2.0 mm up to the height of a tooth, e.g. 2-10 mm.
The device of this construction may have two detection means positioned relative to each other so that when the device is inserted into the mouth one of the two detection means is likely to be positioned adjacent a tooth at or near the gumline and the other is at or near the crown of the tooth. For example if the device of the invention comprises a toothbrush head, the two detection means may be positioned across the width (i.e. the direction perpendicular to the head-handle direction) of the toothbrush head, so that as the head is used for toothbrushing the two detection means are likely to become positioned in the manner described above.
The device according to this embodiment may have at least two detection means, at least two of which are spaced apart at the above-mentioned distances. Suitably the detection of fluorescence emission of the two spaced apart distances may be performed simultaneously. Any difference between the intensity of fluorescence emission detected at the two spaced apart regions can be associated with the presence of biological deposits. Of course the situation may occur that in use one of the spaced apart regions, e.g. one of two or more detection means is not in a position to detect fluorescence emission from a tooth surface, e.g. if it is adjacent a gap in the teeth, mouth tissue, fillings etc. In such a case the difference in intensity of the fluorescence emission detected at the spaced apart regions is likely to exceed the maximum difference that would be expected to occur between a test tooth surface with a biological deposit on it, and a clean surface, and the device may be constructed to ignore all such differences which are greater than a specified certain value, for example responding only to differences between certain specified limits.
In practice it may be found that even when the entire tooth surface is xe2x80x9ccleanxe2x80x9d there may be differences in fluorescence emission from different areas of the teeth. In particular a gradient in fluorescence intensity along the vertical axis of the tooth may be encountered, greater intensity being observed at the cervical, or gingival margin, region near the base of the tooth than at the incisor aspect or crown of the tooth. This gradient may be affected by the presence of biological deposits such as plaque, as more deposit is expected to accumulate near the base of the tooth. Therefore the gradient may be steeper on a tooth where there are biological deposits than is the situation for a clean tooth. Consequently the device of the invention may be constructed to observe the presence of, and/or measure such a gradient as the device moves from one part of a tooth surface to another. For example the device may be constructed to detect and/or measure changes in such a gradient, e.g. a reduction of steepness of this gradient, during a process of tooth cleaning, because as biological deposits are removed from e.g. the base of the tooth the gradient of fluorescence emission intensity between the base and the crown is likely to decrease. The device may be constructed to use this for the indication of the presence of biological deposit on a test tooth surface.
The device of this last described embodiment is particularly suited to detect biological deposits on a single tooth, and may also be suitable for detecting dental deposits somewhere among a plurality of teeth or among all of the user""s teeth, for example giving the user a xe2x80x9cwhole mouthxe2x80x9d indication of the presence of biological deposits somewhere in the whole mouth of the user.
The setting up and calibration of the device of the invention, e.g. setting of the limits of fluorescence emission intensity to be detected and measured and associated with the presence of biological deposits on test tooth surfaces, setting the limits of intensity between which the device responds etc is a matter of design for any specific construction of the device of the invention. Using modern electronics and internally embedded software this may be easily achieved by means within the competence of those skilled in the art. For example the device of the invention may be set to respond to a difference of a specified percentage between fluorescence emission intensity from clean tooth surfaces and test tooth surfaces on which there is a deposit of biological deposit. For example the device may be set to respond to a difference in the range 1-90%, e.g. in the range 1-5%, or 1-10%, or 1-20%, or 30% or more between fluorescence emission intensity from clean tooth surfaces and test tooth surfaces on which there is a deposit of biological deposit.
The means to associate the comparison thus obtained with the presence of biological deposit such as dental plaque on the test tooth surface may also comprise a signal/data processing system, programed to associate a difference in the intensity of the auto fluorescence emission produced from the test tooth surface and that associated with auto fluorescence emission from a substantially biological deposit-free tooth surface with the presence of biological deposits such as plaque. This signal/data processing system may comprise an application specific integrated circuit (xe2x80x9cASICxe2x80x9d) built into the device. For example the data processing system may associate any such difference with the presence of deposits such as plaque. Alternately the data processing system may be programmed to associate only differences of greater than a predetermined amount with the presence of deposits such as plaque, for example within the limits mentioned above.
A further aspect of this invention is based upon the fact that dental plaque on a tooth surface has its own inherent auto fluorescence, for example as discussed in the state of the art referred to above, e.g. U.S. Pat. No. 5,382,163, DE 29704185, DE 29705934, EP 0774235, and also WO 97/01298 which disclose wavelengths at which such auto fluorescence is emitted, for example above ca. 600 nm.
Auto fluorescence emission when biological deposits on tooth surfaces, believed to be dental plaque, are illuminated with radiation at wavelengths below ca. 50 nm, preferably  less than 450 nm has been discovered, with emission maxima between ca. 530 nm and ca. 630 nm, in particular having two emission maxima, one at ca. 540-550 nm and another at ca. 610-620 nm. The discovery of these two maxima is believed to be novel.
When only a small amount of biological deposit is present on the teeth then the auto fluorescence associated with tooth surfaces free or substantially free from biological deposit may be so intense that the auto fluorescence emission from the deposit itself or its constituents such as dental plaque is not observed, i.e. it is swamped by the auto fluorescence associated with tooth surface material itself. However as the amount of biological deposits such as plaque on the tooth increases and/or the age of the deposit increases the auto fluorescence emitted by the deposit itself or its constituents such as dental plaque generally increases until this auto fluorescence is of such an intensity that it can be detected in spite of the auto fluorescence associated with tooth surfaces free or substantially free from biological deposits. When the deposit is very thick or aged the auto fluorescence emission from the deposit itself or its constituents dominates and can be easily measured in spite of the auto fluorescence associated with tooth surface material itself.
Consequently a continuum exists in that when only small quantities of deposit or only a thin layer of biological deposit are present then the apparatus and method of the first aspect of this invention as described above may be used to detect the biological deposit, and when more biological deposit is present measurement of the auto fluorescence emissions from the biological deposit or its constituents such as plaque itself may be used.
Therefore in a preferred embodiment of this invention, the apparatus of the invention additionally comprises;
detection means to detect auto fluorescence emission from the test tooth surface at a wavelength associated with auto fluorescence emission from biological deposits on a tooth surface, and
means to relate this auto fluorescence emission to the presence of biological deposit on the test tooth surface, and
indicator means to indicate the presence of biological deposit to a user of the apparatus.
Preferably the detection means is capable of detecting auto fluorescence emission from the test tooth surface at a wavelength associated with auto fluorescence emission from dental plaque on the tooth surface.
These detection means may detect auto fluorescence emission from the biological deposits being of the wavelengths associated with autofluorescence from dental plaque disclosed in the state of the art discussed above. Preferably the means detects either or both of the emission maxima between ca. 530 nm and ca. 630 nm referred to above.
The use of this auto fluorescence emission, referred to above, from biological deposits such as dental plaque deposits on tooth surfaces is itself believed to be novel. Therefore in a further aspect of this invention, an apparatus for the detection of biological deposits on a test surface of a tooth, in particular dental plaque, is provided comprising;
detection means for the detection of auto fluorescence emission from biological deposits on a test tooth surface between ca. 530 nm and ca. 630 nm;
means to relate this auto fluorescence emission from the biological deposits to the presence of biological deposits on the test tooth surface and;
indicator means to indicate the presence of biological deposits to a user of the apparatus.
Preferably the detection of auto fluorescence is carried out at one or both of the two emission maxima mentioned above, i.e. the one at ca. 540-550 nm and another at ca. 610-620 nm.
Suitably the auto fluorescence emission from biological deposits is produced by means to direct exciting radiation onto a test tooth surface. This exciting radiation may be exciting radiation at the wavelength used in the apparatus of the first aspect of this invention.
Suitably the illumination means for the above aspects and preferred embodiments of this invention may comprise a light emitter such as a light emitting diode (LED) capable of emitting radiation in the blue region of the visible spectrum, preferably including radiation between 430 and 500 nm. Such LED""s, emitting radiation at 480xc2x150 nm are commercially available. The LED should preferably be of low power to minimize consumption, and LED""s operating at a power of 5-20 mA are suitable.
The exciting radiation from such an LED may be directed to the tooth surface by a light guide, for example one or more, e.g. a bundle, of optical fibres. Conventional commercially available optical fibres may be used, and preferably for insertion into the user""s mouth plastic material rather than glass fibres are used, to minimize any risk of breakage or scratching of the user""s gums or other parts of the user""s mouth tissues. Suitable materials for the optical fibres should not emit any fluorescence when illuminated with the exciting radiation. Optical fibres of ca. 0.25-2.0 nm (i.e. 250 micron-2.0 nm) have been found suitable for this purpose, and a bundle of these up to ca. 4 mm is found suitable, depending on the area of tooth surface that is to be tested for biological deposits such as dental plaque. It may be appropriate to incorporate optical filters into the optical path between the light emitter and the test tooth surface to ensure that excitation radiation of wavelengths that causes fluorescence emission is preferentially directed to the test tooth surface. It may also be appropriate to incorporate focusing optics, e.g. one or more lenses, into the optical path between the light emitter and the test tooth surface to ensure that exciting radiation is focused and concentrated onto the test tooth surface.
If the illumination means emits radiation with a wavelength below ca 420 nm then it is preferred, for safety reasons, to include a cut-off filter to prevent such radiation reaching the tissues of the user. Suitable filters of this type are known. A suitable type of filter is a dichroic filter, e.g. dichroic mirrors which reflect at the wavelength of the exciting radiation and transmit at the wavelength of the emitted fluorescence radiation, which are preferred as a cheap and convenient way of cutting out such low wavelength radiation.
The detector means may comprise a conventional detector e.g. a semiconductor photodiode. It may be appropriate to incorporate optical filters into the optical path between the detector and the test tooth surface to ensure that fluorescence emission is preferentially guided to the detector. It may also be appropriate to incorporate focusing optics, e.g. one or more lenses, into the optical path between the detector and the test tooth surface to ensure that fluorescent emission is focused and concentrated onto the detector. The detector means may also comprise a light guide, for example one or more optical fibres, e.g. a bundle as described above, to guide fluorescence emission from the tooth surface to a detector for the fluorescence emission radiation.
Although separate light guides for the exciting radiation and fluorescence emission radiation may be used, alternatively a single light guide may be used for both over part of the length of the light guides and a beam splitter/combiner of known type may be used to separate the excitation and emission radiation and guide them as appropriate. For example the same optical fibres may be used for guiding both the exciting and emitted fluorescence radiation, and the exciting and emitted fluorescence radiation may be filtered using dichroic filters.
It is preferred to modulate and/or phase lock the excitation radiation and the detection of the fluorescent emission e.g. at 20-500 Hz, e.g. at 100-300 Hz, suitably at around 200 Hz, in synchronisation so that the fluorescence emission can easily be distinguished from unmodulated background radiation, e.g. from light sources outside the user""s mouth. Preferably modulation at around electric mains frequency (generally 50-60 Hz) and multiples thereof should be avoided to avoid interference from electric lights in the environment of the user.
In a preferred embodiment of this invention optical fibres comprising the light guide of the illumination means and the detection means may be bundled together within a suitable conduit, and may terminate at a common optical probe, for example a transparent cover or a focusing transmitting/collecting probe. Such a probe may incorporate one or more lenses which may focus exciting radiation from the illumination means onto the test tooth surface and may focus fluorescence emission from the test tooth surface into the light guide. The optical fibres may be bundled together randomly. Alternatively they may be bundled such that the fibre(s) comprising the light guide of the illumination means or alternatively the fibre(s) comprising the light guide of the detection means may comprise a central core, surrounded by a ring or polygon of fibres comprising respectively the light guide of the detection means, or the light guide of the illumination means. If separate optical fibres are used as light guides for the excitation and emission radiation then preferably a greater number of fibres is used for the light guide of the emission radiation than for the excitation radiation because of the lower intensity of the fluorescence emission radiation.
The means to indicate the presence of biological deposits such as dental plaque to a user of the apparatus may comprise an electronic means which gives a visual, e.g. a light, signal or an audible, e.g. a sound, signal to a user to indicate the presence of such biological deposits. For example the means may give such a signal only when a significant amount of biological deposit is present, and cease to give this signal when the deposit has been removed, or alternately the means may give no signal when biological deposit is present but may give such a signal when the deposit is absent. Alternative indicator modes will be apparent to those skilled in the art. The construction of such a means will be readily apparent to those skilled in the art of electronics.
In a preferred embodiment of this invention the apparatus comprises a toothbrush, for example having means to direct exciting radiation at the test tooth surface and the means to detect fluorescence emission from the test tooth surface incorporated into the toothbrush head, e.g. having one or more optical fibres as described above incorporated and terminating at an optical probe in the toothbrush head, so that the optical probe can be conveniently close to the test tooth surfaces of a user, e.g. within 1 cm or less, being approximately the usual length of toothbrush bristles. Such a toothbrush may also incorporate conventional cleansing bristles in its head, and in one embodiment the cleansing bristles may themselves comprise or incorporate one or more such optical fibres to thereby comprise a probe. The toothbrush may be a toothbrush used by hand action, or more conveniently may be an electric toothbrush, i.e. in which the brush head incorporating the bristles is driven by an electric motor.
The head incorporating the probe may be a permanent part of the toothbrush or alternately and preferably may be replaceable. Conveniently the illumination means, detection means and the various electronic signal/data processing means etc., and a suitable electrical power supply, e.g. a battery or electrical mains connection, may be provided in the handle of the toothbrush. If such a toothbrush has an electrically driven cleaning brush then in such a construction all of the electrical components, e.g. the drive motor etc., can be incorporated into the toothbrush handle.
If the device of the invention is incorporated into a toothbrush then it may be constructed so as to indicate the initial presence of biological deposits on the surface of the user""s teeth and indicate the quantitative reduction or absence of biological deposits after the teeth have been brushed for a suitable period. Such a toothbrush may be constructed to indicate to the user that biological deposits are present somewhere in an area of the user""s teeth, and thus that continued brushing of the teeth is necessary to remove the deposits.
Accordingly the invention also provides a toothbrush which incorporates a device as described above. Preferably such a toothbrush is constructed provided with means to indicate to the user that deposits initially present on the teeth have been removed by the process of brushing the teeth, and/or means to indicate to the user that deposits are still present even after a period of toothbrushing, and that brushing needs to be continued.
Alternately the apparatus may comprise a dental tool, for example a dental tool suitable for use by a dentist carrying Out an in vivo examination of his/her patient""s teeth.
In use the test tooth surfaces may be initially cleaned, e.g. by a preliminary rinse, to remove dirt and other loosely held deposits and contaminants which might obscure the test tooth surface and then apply the apparatus to the test tooth surface. When the apparatus indicates to the user that biological deposit such as plaque is present on the test tooth surface the surface may be cleaned, for example using toothbrush bristles and optionally a dentifrice composition such as a toothpaste, and the apparatus re-applied to the test tooth surface to determine whether the deposit is still present. If deposit is still present the procedure is repeated until the apparatus indicates that the deposit has been removed. Alternatively and particularly if the device comprises a toothbrush, it may simply be applied to the teeth in a toothbrushing process and toothbrushing is continued until the device indicates that deposits have been removed to a satisfactory extent. If a dentrifice is used in the toothbrushing process, preferably it is a dentifrice which contains no constituents which exhibit fluorescence at the wavelengths of fluorescence emission which are detected by the detection means.

Toothbrush with fluorescence means for locating dental plaque


A system for forming and attaching lift-tabs to can ends to form easy opening lift-tab can ends comprises a first frame, a second frame and a tab press for forming a lift-tab. The system also includes a drive roller adapted to move the strip of metal stock material through the tab press. The system further includes a conversion press for attaching a lift-tab onto a can end, a conveyor, a power source, and a crank shaft operatively connected to the power source. The crank shaft is adapted to transmit power for operating either or both of the tab press and the conversion press.

In the production of lift-tab can ends (also known as "easy-open" can ends), the lift-tab is conventionally formed rough-side-up or bottom-side-up. Consequently, it has been necessary to invert the tabs so that they are positioned smooth-side-up, prior to their attachment to can ends. This inversion has generally been accomplished manually, and therefore, it is desirable to provide a method wherein the tab is inverted automatically, thereby saving labor. Alternatively, it is desirable to provide a method of production wherein the lift-tab is formed rough-side-down or top-side-up, thereby eliminating the need for inversion of the lift-tab altogether.
Presses for attaching a lift tab to a can end (known in the industry as "converting" the end to an easy-open can end) are known. Presses of this type are available from the Minister Machine Company of Minister, Ohio. U.S. Pat. No. 4,568,230 shows a layout of a press for processing workpieces into finished can ends with an opening tab attached thereto.
Presses used for the manufacture of easy-open can ends generally comprise a press bed mounted on legs which rest on the floor. Four columns or uprights are mounted on the press bed. The columns or uprights support a crown in which a main drive for the press components is mounted. The columns have slides attached therein for supporting a reciprocating main ram. The main ram carries the upper tooling of the main die set, which cooperates with lower tooling on the bed. The main die set defines a plurality of stations in which the can ends are progressively converted into easy-open can ends. A conveyor carries the can ends into and through the stations of the die set. The tabs are formed by tab tooling, which is supplied with strip stock by a stock feed device. The tab tooling forms a tab and separates it from the strip stock for attachment to a can end.
The tab tooling has conventionally been mounted on the press bed laterally of the conveyor and laterally of the main die. The tab tooling may also be split so that it is arranged laterally on both sides of the main die. A bridge is required to transfer the tab stock strip across the main die set. Such an arrangement is shown in U.S. Pat. No. 4,568,230. The upper tooling is mounted on the main ram of the press.
One of the deficiencies associated with this arrangement of the tooling is that it is difficult to access the tooling for maintenance. Access to the can end tooling is difficult due to the presence of the tab tooling on one side of the main die and the tab tooling and tab stock feed device on the other side of the main die. The lateral placement of the tab tooling also increases the depth of the press from front to back. This requires a larger bed which increases the weight of the press and reduces its speed.

This patent is subject to a terminal disclaimer.

System for forming and securing lift-tabs to can ends having two frames


In an Enhanced Definition Television (EDTV) system, an assistance signal is transmitted to enable a suitably equipped receiver to choose from a number of predetermined deinterlacing modes. The modes represent interpolation options for estimating lines missing in a current interlaced image field, thereby enhancing the vertical resolution of a display. For example, five options may be provided for as follows: (1) intra-frame linear interpolation, (2) use of information from a preceding frame, (3) use of information from a succeeding frame, (4) combining the results of (1) and (2), and (5) combining the results of (1) and (3). Preferably, interpolation options are derived on a block basis and transmitted with coded motion vectors which may be compressed to make maximum use of the available bandwidth. The assistance signal may be transmitted within the vertical and/or horizontal blanking intervals of an interlaced television broadcast.

This invention relates to the use of assistance signals for improved image resolution in Enhanced Definition Television (EDTV).
Current U.S. television broadcast signals conform with a standard formulated by the National Television System Committee (NTSC), providing for 525 horizontal scan lines, a 4-to-3 screen aspect ratio, and allocation of a bandwidth of 6 megahertz per communications channel. This standard further calls for alternating transmission of the odd-numbered and the even-numbered scan lines.
As compared, e.g., with 35-mm motion-picture images, transmissions based on the NTSC standard produce images with less resolution of detail and a less appealing aspect ratio, and similar observations apply to a different standard for conventional resolution television known as PAL (Phase Alternation Line) in use elsewhere. In view of these shortcomings, and to improve upon current television image quality, there have been proposals for a new standard for so-called high-definition television (HDTV) with greater vertical and horizontal resolution. Practicable proposed systems are incompatible with reception by receivers in current use. As an alternative, systems have been proposed which retain compatibility with current receiver standards and which use an auxiliary, low-bandwidth channel of assistance information to help improve upon the quality of present-day broadcasts. Though sometimes also referred to as HDTV in the literature, such systems are more appropriately referred to as enhanced-definition TV (EDTV), and they may be considered as an interim to the introduction of HDTV.
The following are cited as background in the field of HDTV/EDTV:
U.S. Pat. No. 4,916,525, issued Apr. 10, 1990 to J. E. Drummond discloses a system in which compressed vertical resolution-enhancing image data is transmitted during the vertical flyback interval of an NTSC television signal. An appropriately equipped receiver can decompress the compressed image data and add the expanded lines of data to the normal image data of the NTSC signal in interlinear fashion. In a receiver not so equipped, the added data is simply ignored.
U.S. Pat. No. 4,967,263, issued Oct. 30, 1990 to C. B. Dieterich; U.S. Pat. No. 4,926,244, issued May 15, 1990 to M. A. Isnardi; the paper by M. A. Isnardi et al., "Encoding for Compatibility and Recoverability in the ACTV System", IEEE Transactions on Broadcasting, Vol. BC-33 (1987 ), pp. 116-213; and the paper by S. N. Baron et al., "An Evolutionary Approach to Advanced Television Services: The ACTV (Advanced Compatible Television) System" each discloses a four-component, wide-screen, NTSC-compatible EDTV transmission format in which the first component has the aspect ratio and bandwidth specifications of a standard NTSC signal, and in which the other three components contain new information which is added to the first component in a compatible manner to provide a wider aspect ratio and enhanced definition. The transmitter inserts compressed high-frequency components of the side panel information and horizontal-resolution-enhancing information in a portion of the bandwidth allocated to the chrominance signal, and also provides a vertical-temporal helper signal at baseband to be used by the EDTV receiver for deinterlacing the received signal. The vertical-temporal helper signal consists of the difference between a calculated temporal average value and the actual value of the missing progressive scan line.
U.S. Pat. No. 4,980,764, issued Dec. 25, 1990 to J. M. Henot discloses the use of a helper signal in the transmission of image blocks and superblocks.
B. Girod et al., "Motion-compensating Field Interpolation from Interlaced and Non-interlaced Grids", 2nd International Technical Symposium on Optical and Electro-Optical Applied Science and Engineering: Image Processing Symposium, Cannes, December 1985, pp. 1-8 discloses motion-compensated interpolation of non-interlaced and interlaced grids for minimizing blur and jerkiness.
M. Pecot et al., "Compatible Coding of Television Images, Part 1: Coding Algorithm", Image Communication Journal (Special Issue on HDTV), pp. 1-18 discloses optimization of band splitting and decomposition filters in sub-band coding of high-resolution image information.
G. W. Meeker, "High Definition and High Frame Rate Compatible N.T.S.C Broadcast Television System", IEEE Transactions on Broadcasting, Vol. 34 (1988), pp. 313-322 discloses a wide-screen, high-definition television system which is compatible with the present NTSC system. The transmitter inserts horizontal-resolution-enhancing information in the bandwidth reserved for the chrominance signal and provides within the NTSC bandwidth motion vectors to be used by the receiver for motion compensated deinterlacing for enhancing vertical resolution.
T. Fukinuki et al., "Extended Definition TV Fully Compatible with Existing Standards", IEEE Transactions on Communications, Vol. COM-32 (1984), pp. 948-953 and T. Fukinuki et al., "Extended-Definition TV Fully Compatible with Existing Standards--Proposal and Experimental Results", 1984 Winter TV Conference, pp. 354-367 disclose an EDTV system which is compatible with existing NTSC or PAL standards. Horizontal resolution is improved by the transmitter inserting high-resolution luminance components in unused portions of the bandwidth allocated to the chrominance signal. The high-resolution components are detected at an appropriately equipped receiver by field-to-field processing.
W. F. Schreiber et al., "A Compatible High-Definition Television System Using the Noise-Margin Method of Hiding Enhancement Information", SMPTE Journal, December 1989, pp. 873-879 discloses an NTSC receiver-compatible EDTV system in which digital audio and horizontal-resolution-enhancing information are inserted by the transmitter in excess chrominance bandwidth.

Digitally assisted motion compensated deinterlacing for enhanced definition television

The Trustees of Columbia University in the City of New York


Embodiments of the present disclosure provide a circuit, touch chip, and electronic device for capacitance detection, the circuit for capacitance detection comprising: a control module, a charge transfer module, a processing module, a driving module, and an offsetting module, the control module being configured to charge a detection capacitor by controlling the driving module, the offsetting module being configured to charge an offset capacitor, and control the offset capacitor to perform charge offsetting on the detection capacitor; the charge transfer module being configured to convert charge of the detection capacitor after the charge offsetting to generate an output voltage; and the processing module being configured to determine, based on the output voltage, a capacitance variation of the detection capacitor before and after the detection capacitor is affected by an external electric field.

The principle of self-capacitance detection is that a capacitor will be formed between a detection electrode and system ground, which is known as the self-capacitance detection. When no external electric field is caused by, e.g., a finger, the capacitor formed between the detection electrode and the system ground has base capacitance or initial capacitance. When the finger approaches or touches the detection electrode, the capacitance between the detection electrode and the system ground will be increased, and a user-related touch control operation may be determined by detecting a variation of the capacitance.
In the field of capacitance touch control, the flexible screen is an important development direction. When capacitance touch detection is implemented using the above-mentioned self-capacitance principle, since the flexible screen is often thinner than a conventional capacitance touch screen, the detection electrode is nearer to the system ground. Thus, the base capacitance of the capacitor is obviously higher than the base capacitance of the capacitor of the conventional capacitance touch screen. In addition, since a metal-mesh is used as the detection electrode, the sensing area is relatively small, such that when the finger touches the capacitor, the capacitance variation is very small. A small capacitance variation means to require a high circuit gain, such that the detection circuit can detect an electrical signal generated by the capacitance variation during touching, but since the base capacitance is much higher than the capacitance variation, a high circuit gain, if employed, further tends to cause detection circuit saturation.
In addition, the small capacitance variation also generates a very small electrical signal, which is easily submerged in circuit noise, thus failing to be detected. Thus, it can be seen that, the related art has low sensitivity of the self-capacitance detection, finally resulting in the defect of low accuracy of the self-capacitance detection.

Circuit, touch chip, and electronic device for capacitance detection


A communication apparatus includes contacts for exchanging various data between a FAX terminal and a radio terminal having a display function to connect the FAX terminal and the radio terminal to cause the FAX terminal and the radio terminal to exchange necessary data therebetween, wherein display data is transferred from the FAX terminal to the radio terminal having the display function and is displayed on the radio terminal.

1. Field of the Invention
The present invention relates to a communication apparatus for connecting a FAX terminal and a radio terminal to perform communication.
2. Related Background Art
When a facsimile unit is conventionally connected to a portable telephone set having a display function, speech signals are simply connected between ;hem.
That is, a sound signal output of a radio terminal and a sound signal input of a FAX terminal are combined and used as a communication apparatus.
Thus, a transmission document sheet cannot be sensed on the radio terminal side because the radio terminal is connected to the FAX terminal by only acoustic coupling.
Radio terminal information cannot be obtained at the FAX terminal.
The radio terminal simply performs the capture/release of a line and modulation/demodulation between the radio and speech signals. The radio terminal does not identify whether the calling party is a FAX unit or man.
In the above communication apparatus, however, the facsimile unit must have a display unit to display a facsimile operating state (e.g., "on copying", "on transmission", or "on reception"), and the telephone number, abbreviation, and the like of a partner station. The display causes an increase in cost. In addition, the displays are disadvantageously arranged in both the facsimile unit and the portable telephone set.
When a partner station makes a call for FAX communication, the portable telephone set cannot ring directly.
When a call is made from the portable telephone set to perform a facsimile transmission operation, and actual transmission cannot be performed due to a busy state or the like of the partner station, the call operation must be repeated to perform retransmission, resulting in cumbersome operations.
To make a call to a partner FAX station, a call reservation key in the facsimile unit must be depressed. When the facsimile unit is located away from the portable telephone set, the operator must move to the location where the facsimile unit is installed, and must undesirably operate the console unit of the facsimile unit.
If a conventional apparatus does not have a call function in a FAX main unit, a call must be made at a unit other than the FAX main unit, and the operator judges the partner station as a FAX station and performs transmission. For this reason, the unit having a call function cannot determine whether the FAX unit has a transmission document sheet, and a telephone number for a FAX unit and the telephone number for a telephone set cannot be registered for a partner station.
In the above communication apparatus, when the facsimile unit is connected to a plurality of portable telephone sets and a telephone number is used in TSI or CSI for partner facsimile stations, this telephone number cannot be used or the telephone number must be registered in the facsimile unit every time a new portable telephone set is connected thereto.
When a plurality of radio terminals are connected to one FAX unit, communication reports cannot be stored for every terminal, and the operator can know only a FAX communication quantity.
When an incoming call is made to a radio terminal from a partner FAX unit, the operator must answer the phone with the portable telephone set. If the operator judges the call as a FAX call, the operator must depress a start key in the facsimile unit, resulting in cumbersome operations.
Any conventional communication apparatus which can solve all the conventional problems described above is not yet proposed.

Communication apparatus having inter-communicating device for exchanging data between fax terminal and radio terminal


An improved method is provided for controlling a power tool having a rotary shaft. The method includes: disposing an inertial mass in a housing of the power tool, such that the inertial mass is freely rotatable about an axis of rotation which is axially aligned with the rotary shaft; monitoring rotational motion of the power tool in relation to the inertial mass during operation of the power tool; and activating a protective operation based on the rotational motion of the power tool in relation to the inertial mass.

The use of large rotary hammers is an effective way to bore holes into stone or concrete. Unfortunately, there are users who improperly use this type of power tool. For instance, when a user is holding the tool upright while drilling downward, there is a tendency to relax the grip on the rear handle. Since the rotational grab of the tool is minimized by the hammering action, it only takes a little force from the rear handle to stabilize the tool. The careless operator may not use the side handle, which is specifically designed to allow the user to manage the high torque created by stall conditions. Unfortunately, when the rotating bit encounters a piece of solid rock or rebar buried within the material, a jam condition could occur. When the bit jams, the rotational torque is instantly transferred to the tool housing. Since the user only has a slight grip on the rear handle, the tool housing will rotate. The clutch within the tool is typically set to a high level so as to handle relatively high torque situations. Even if the trigger is released as the tool twists out of the user's hand, the rotational motion of the tool is sufficient to injure the user.
Therefore, it is desirable to provide a method for controlling a power tool, such as a rotary hammer, at the onset of such a bit jam condition.


Supported catalysts are produced with nanometer sized particles comprised of different metals dispersed throughout the catalyst support material. The supported catalysts reduce substantially or completely the amount of platinum that is required without sacrificing catalytic performance. In place of platinum, the supported catalysts employ palladium, silver, or copper, all of which costs significantly less than platinum.

1. Field of the Invention
The present invention relates to the production of supported catalysts, more specifically to the method for making supported catalysts containing nanometer sized particles comprised of different metals dispersed throughout the catalyst support material.
2. Description of the Related Art
Many industrial products such as fuels, lubricants, polymers, fibers, drugs, and other chemicals would not be manufacturable without the use of catalysts. Catalysts are also essential for the reduction of pollutants, particularly air pollutants created during the production of energy and by automobiles. The majority of industrial catalysts are composed of a high surface area support material upon which chemically active metal nanoparticles (i.e., nanometer sized metal particles) are dispersed. The support materials are generally inert, ceramic type materials having surface areas on the order of hundreds of square meters/gram. This high specific surface area usually requires a complex internal pore system. The metal nanoparticles are deposited on the support and dispersed throughout this internal pore system, and are generally between 1 and 100 nanometers in size.
Processes for making supported catalysts go back many years. One such process for making platinum catalysts, for example, involves the contacting of a support material such as alumina with a metal salt solution such as chloroplatinate acid. The salt solution "impregnates" or fills the pores of the support during this process. Following the impregnation, the support containing the salt solution would be air dried, causing the metal salt to precipitate within the pores. The support containing the crystallized metal salt would then be exposed to a hydrogen or carbon monoxide gas environment, reducing the solid metal salt to metal particles. The currently used methods for producing supported catalysts, including impregnation methods, are further discussed below.
Yoo et al., in an article entitled "Propene Hydrogenation Over Truncated Octahedral Pt Nanoparticles Supported on Alumina," Journal of Catalysis, Vol. 214, pp. 1-7 (2003), disclose a process for loading colloidal platinum (Pt) nanoparticles (synthesized by a 1:5 concentration ratio of K2PtCl4 to polyacrylate capping polymer) into an alumina support via impregnation.
Miyazaki et al., in an article entitled "Morphology Control of Platinum Nanoparticles and Their Catalytic Properties," Journal of Nanoparticle Research, Vol. 5, pp. 69-80 (2003), disclose the preparation of Pt nanoparticles of varying morphology through the use of different capping polymers. Various shapes (such as square, triangular, and hexagonal) of Pt crystallites, as observed by transmission electron microscopy (TEM), were obtained. Supported catalysts were made by impregnation of previously formed Pt crystallites into an alumina support. Water was removed from the support by freeze drying, and the capping polymers were removed by calcinating in air at 500° C. for 8 hours.
U.S. Pat. No. 6,569,358 discloses a method of preparing a porous material incorporating ultrafine metal particles comprising the following steps: (1) preparing surface-protected ultrafine metal particles by reducing metal ions in the presence of molecules such as dodecanethiol molecules; (2) immersing a wet gel in a solution of the ultrafine metal particles, thus forming an ultrafine metal particle/wet gel composite in which the ultrafine metal particles are incorporated in the wet gel; and (3) drying the ultrafine metal particle/wet gel composite to form a porous body.
The process disclosed in U.S. Pat. No. 6,569,358 utilizes protecting agents or capping polymers. However, removal of protecting agents or capping polymers can be an issue for sensitive catalytic processes, as their destruction may leave contaminating residues that are undesirable. These residues may reduce activity of the catalyst by occupying active sites necessary for subsequent reactions. The residues may also leave behind trace quantities of poisons that will eventually kill the catalyst over time. Removal of organic capping agents and polymers usually require oxidation (or burning), but the heat required for such oxidation may produce unwanted sintering due to the high temperatures. Sintering will increase the metal particle size and reduce the active surface area of the catalyst. Furthermore, the use of capping agents can hinder the introduction of the metal crystallites into small pores of the support.
U.S. Pat. No. 6,686,308 discloses a supported catalyst comprising catalyst metal nanoparticles having an average particle size of typically 2.0 nm or less, which are supported on support materials at a loading of 30% or more. It teaches the use of platinum, palladium, ruthenium, rhodium, iridium, osmium, molybdenum, tungsten, iron, nickel or tin, as catalyst metals, and the use of carbon as the support material. The method of making a supported catalyst disclosed in U.S. Pat. No. 6,686,308 comprises the steps of: (1) providing a solution of metal chlorides of one or more catalyst metals in a solvent system containing at least one polyalcohol, typically ethylene glycol containing less than 2% water; (2) forming a colloidal suspension of unprotected catalyst metal nanoparticles by raising the pH of the solution, typically to a pH of 10 or higher, and heating the solution, typically to 125° C. or higher; (3) adding support particles to the colloidal suspension; and (4) depositing the unprotected catalyst metal nanoparticles on the support particles by lowering the pH of the solution, typically to a pH of 6.5 or lower.
U.S. Pat. No. 6,603,038 discloses a method for producing a catalyst containing one or several metals from the group of metals comprising the sub-groups Ib and VIIIb of the periodic table on porous support materials, characterized by a first step, in which one or several precursors from the group of metal compounds from sub-groups Ib and VIIIb of the periodic table is or are applied to a porous support, and a second step in which the nanoporous support to which at least one precursor has been applied, is treated with at least one reduction agent to obtain the metal nanoparticles produced in situ in the pores of the support. In the first step, catalysts were prepared by impregnation of the support with a metal salt solution, followed by a drying step. Subsequent to drying, as part of the second step, the impregnated support materials were reduced by various techniques including re-impregnation with liquid reducing agents.

Method of producing multi-component catalysts


Methods and apparatus of processing cube face images are disclosed. According to embodiments of the present invention, one or more discontinuous boundaries within each assembled cubic frame are determined and used for selective filtering, where the filtering process is skipped at said one or more discontinuous boundaries within each assembled cubic frame when the filtering process is enabled. Furthermore, the filtering process is applied to one or more continuous areas in each assembled cubic frame.

The 360-degree video, also known as immersive video is an emerging technology, which can provide "feeling as sensation of present". The sense of immersion is achieved by surrounding a user with wrap-around scene covering a panoramic view, in particular, 360-degree field of view. The "feeling as sensation of present" can be further improved by stereographic rendering. Accordingly, the panoramic video is being widely used in Virtual Reality (VR) applications.
Immersive video involves the capturing a scene using multiple cameras to cover a panoramic view, such as 360-degree field of view. The immersive camera usually uses a set of cameras, arranged to capture 360-degree field of view. Typically, two or more cameras are used for the immersive camera. All videos must be taken simultaneously and separate fragments (also called separate perspectives) of the scene are recorded. Furthermore, the set of cameras are often arranged to capture views horizontally, while other arrangements of the cameras are possible.
FIG. 1 illustrates an exemplary processing chain for 360-degree spherical panoramic pictures. The 360-degree spherical panoramic pictures may be captured using a 360-degree spherical panoramic camera, such as a 3D capture device. Spherical image processing unit 110 accepts the raw image data from the 3D capture device to form 360-degree spherical panoramic pictures. The spherical image processing may include image stitching and camera calibration. The spherical image processing is known in the field and the details are omitted in this disclosure. An example of a 360-degree spherical panoramic picture from the spherical image processing unit 110 is shown as picture 112 in FIG. 1. The top side of the 360-degree spherical panoramic picture corresponds to the vertical top (or sky) and the bottom side points to ground if the camera is oriented so that the top points up. However, if the camera is equipped with a gyro, the vertical top side can always be determined regardless how the camera is oriented. In the 360-degree spherical panoramic format, the contents in the scene appear to be distorted. Often, the spherical format is projected to the surfaces of a cube as an alternative 360-degree format. The conversion can be performed by a projection conversion unit 120 to derive the six face images 122 corresponding to the six faces of a cube. On the faces of the cube, these six images are connected at the edges of the cube.
In order to preserve the continuity of neighboring cubic faces sharing a common cubic edge, various cubic face assembly techniques have been disclosed in an related U.S. Non-provisional patent application Ser. No. 15/390,954, files on Dec. 27, 2016, with some common inventors and the same assignee. The assembled cubic-face frames may help to improve coding efficiency. Accordingly, cubic face assembler 130 is used to assemble the six cubic faces into an assembled cubic-face frame. The assembled image sequence is then subject to further processing. The cubic face assembler 130 may generate fully connected cubic-face frames or partially connected cubic-face frames. Since the 360-degree image sequences may require large storage space or require high bandwidth for transmission, video encoding by a video encoder 140 may be applied to the video sequence consisting of a sequence of assembled cubic-face frames. At a receiver side or display side, the compressed video data is decoded using a video decoder 150 to recover the sequence of assembled cubic-face frames for display on a display device (e.g. a 3D display). Information related to the assembled cubic-face frames may be provided to the video encoder 140 for encoding efficiently and/or properly and rendering appropriately.
FIG. 2 illustrates an example of the project conversion process to project a spherical panoramic picture into six cubic faces on a cube 210. The six cubic faces are separated into two groups. The first group 220 corresponds to the three cubic faces, labelled as 3, 4 and 5, that are visible from the front side. The second group 230 corresponds to the three cubic faces, labelled as 1, 2 and 6, that are visible from the back side of the cube.
In conventional video coding or processing, the coding or processing system always assumes the input video sequence. Therefore, the cubic faces are further assembled into cubic-face frames. FIG. 3A illustrates two examples cubic-face assembled frames (310 and 320) with blank areas, where two sets of fully interconnected cubic faces correspond to two different way of unfolding the six faces from the cube. The unfolded cubic faces (also called a cubic net) are fitted into a smallest rectangular frame with blank areas filled with dummy data.
FIG. 3B illustrates examples of another type of cubic-face assembling, where the six faces are assembled into a rectangular frame without blank area. In FIG. 3B, frame 330 corresponds to a 1×6 assembled cubic frame, frame 340 corresponds to a 2×3 assembled cubic frame, frame 350 corresponds to a 3×2 assembled cubic frame and frame 360 corresponds to a 6×1 assembled cubic frame. As shown in FIG. 3B, the six cubic faces are compactly fitted into a rectangle without any blank area.
FIG. 4A illustrates an exemplary block diagram of a video encoder system, such as HEVC (High Efficiency Video Coding), incorporating adaptive Inter/Intra prediction. The system includes two prediction modes: Inter prediction 420 and Intra prediction 430. The Inter Prediction 420 utilizes motion estimation (ME) and motion compensation (MC) to generate temporal prediction for a current frame 410 based on previous reconstructed picture or pictures. The previous reconstructed pictures, also referred as reference pictures, are stored in the Frame Buffer 480. As is known in the field, the ME for the Inter prediction uses translational motion model, where the motion can be specified by an associated motion vector. The Intra prediction 430 generates a predictor for a current block by using reconstructed pixels at neighboring blocks in the same slice or picture. A switch 445 is used to select among Inter prediction 420 and the Intra prediction 430. The selected prediction is subtracted from the corresponding signal of the current frame to generate prediction residuals using an Adder 440. The prediction residuals are processed using DCT (Discrete Cosine Transform) and Quantization (DCT/Q) 450 followed by Entropy Coder 460 to generate video bitstream. Since reconstructed pictures are also required in the encoder side to form reference pictures. Accordingly, Inverse Quantization and Inverse DCT (IQ/IDCT) 452 are also used to generate reconstructed prediction residuals. The reconstructed residuals are then added with the prediction selected by the switch 445 to form reconstructed video data using another adder 442. In-loop Filtering 470 is often used to reduce coding artifacts due to compression before the reconstructed video is stored in the Frame Buffer 480. For example, deblocking filter and Sample Adaptive Offset (SAO) have been used in HEVC. Adaptive Loop Filter (ALF) is another type of in-loop filter that may be used to reduce artifacts in coded images.
FIG. 4B illustrates an example of decoder system block diagram corresponding to the encoder in FIG. 4A. In FIG. 4A, the encoder side also includes a decoder loop to reconstruct the reference video at the encoder side. Most decoder components are used in the encoder side already except for the Entropy Decoder 461. Furthermore, only motion compensation is required for Inter prediction decoder 421 since the motion vectors can be derived from the video bitstream and there is no need for searching for the best motion vectors.
As shown in FIG. 4A and FIG. 4B, a coding system often applies filtering to the reconstructed image in order to enhance visual quality by reducing the coding artifacts. In other video processing systems, filtering may also be applied to the underlying frames to reduce noise or to enhance image quality. However, the assembled frames converted from 3D source video may contain some special features that may cause artifacts or reduce coding efficiency during conventional filtering. According, the present invention addresses filtering issues associated with assembled cubic frames.

Method and apparatus for selective filtering of cubic-face frames


A deep bed upflow filter (10) for removing suspended solids from an influent stream to provide a clean filtrate, comprising an upright vessel (12) having a vertical axis (14), top and bottom ends (16,18) and contiguous upper (20), lower (22), and intermediate (24) regions between the ends. The upper region contains filtrate (26) up to a first elevation (28) and an outlet (30) for drawing the filtrate out of the vessel. The intermediate region contains particulate filter media (32) for removing the suspended solids from influent moving upwardly through the media as the media, dirtied with solids, moves downwardly into the lower region. The lower region is generally tapered (36) inwardly toward the vessel bottom and contains dirty media (34) that has moved downwardly from the intermediate region. Influent is introduced (44) between the intermediate and lower regions, and the dirty media is collected (46) at the bottom and transported (50) to a regenerative washing compartment (52). A portion of the reject flow (64 ) from the wash compartment is delivered (72,74) to the dirty media in the lower region of the vessel and another portion (72,78) is delivered to the area (46,48,50) where the dirty media is collected and transported. This latter portion is preferably introduced into a collection conduit (46) through a pipe (130) having a concentric inner tube (140) by which air is injected to fluidize and move the mixture of air, dirty media, and reject water in the conduit (46) toward an airlift (48,148).

The present invention relates to deep bed sand filters, and more particularly, to an upflow type of deep bed sand filter.
For many years, deep beds of sand, or other fine particulates, have been utilized for filtering relatively large quantities of liquid, for example, the secondary treatment of industrial waste water or the like. In the most primitive deep bed sand filters, the filtered solids which have been "trapped" among the sand particulates, can be removed from the filter only by throwing away the "dirty" sand.
In more advanced filters, the filter media has been conserved by a variety of techniques most-of which draw the dirty sand from the bottom of the filter vessel and pass the dirty sand through a media washing chamber situated either externally or internally of the vessel.
In one type of regenerative filter, the influent is introduced in the upper portion of the filter vessel above the sand bed, and the flow of both liquid and sand is in a downward direction in the vessel. This is represented by the filters described in U.S. Pat. No. 4,060,484 issued Nov. 29, 1977, and U.S. Pat. No. 4,891,142 issued Jan. 2, 1990.
Another approach, represented by U.S. Pat. No. 4,126,546 issued Nov. 21, 1978, and U.S. Pat. No. 4,246,102 issued Jan. 20, 1981 introduces the influent at an intermediate elevation within the sand bed, such that the fluid flows upwardly in the vessel, while the sand moves downwardly.
The patents mentioned above, as well as others such as U.S. Pat. No. 5,019,278 issued May 28, 1991, disclose a variety of said washing techniques, some of which use a portion of the filtrate as the washing medium. It can readily be appreciated that the use of filtrate in this manner, reduces the amount of filtrate that can be drawn from the filter vessel as "clean" water for subsequent, higher value use. In other words, known regenerative deep bed sand filters of the type that use filtrate as the wash medium, have an excessive percentage of the filtrate "wasted" in the reject flow.


A vehicle, such as a motorcycle, that includes an engine air intake arrangement with a variable length intake passage. The motorcycle includes an engine having an intake port. A fixed funnel delivers air to the intake port of the engine. A moveable funnel is positioned on the intake side of the fixed funnel and selectively cooperates with the fixed funnel to deliver air to the intake port of the engine. A parallel linkage moveably supports the moveable funnel relative to the fixed funnel. An air cleaner box, in which the fixed funnel and the moveable funnel are disposed, includes a protrusion at a portion that covers the moveable funnel and that prevents the occurrence of contact with the moveable funnel.

1. Field of the Invention
The present invention relates to a vehicle and more particularly to a vehicle equipped with a funnel for introducing air to an intake port of an engine.
2. Description of the Related Art
Intake devices are known that are equipped with a funnel for introducing air to an intake port of an engine. For example, Japanese Patent Publication No. 02-223632 shows one such arrangement in which an intake device is equipped with a fixed funnel for delivering air, entering from a an upstream side of an air cleaner box, to an intake port of an engine. An extension pipe, or moveable funnel, is capable of being selectively coupled to the fixed funnel. A case, such as the air cleaner box, houses the fixed funnel and moveable funnel. The intake device is housed inside a tank cover in which a fuel tank is disposed. In addition, in order that an inner wall surface of the case and the moveable funnel do not come into contact, the case is structured such that the space of a portion of the case, which corresponds with the position to which the moveable funnel is moved when it is separated away from the funnel, is enlarged.

Engine air intake arrangement for a vehicle


A method for communicating packet multimedia data between a source endpoint and a destination endpoint is disclosed, wherein at least the source endpoint is within a virtual private network, and comprises the steps of receiving, at a signaling controller, a first signaling packet from the source endpoint, wherein the source endpoint is within a virtual private network; determining whether the source endpoint and destination endpoint may communicate directly over the same virtual private network; when the source endpoint and destination endpoint cannot communicate directly over the same virtual private network, associating a unique identifier of the source endpoint with a virtual private network identification marker; when the source endpoint and destination endpoint can communicate directly over the same virtual private network, instructing the source endpoint and destination endpoint to communicate media packets directly.

The present invention relates to Network communication carriers currently provide network-based virtual private network (VPN) capabilities over their networks. Generally providing VPN capabilities requires the use of technologies such as virtual routing at edge access routers and aggregation routers, multi-protocol label switching (MPLS), asynchronous transfer mode (ATM) permanent virtual circuits (PVCs), and the like, in devices that make up the backbone of the network. The virtual routing technology allows the carrier to present, to each of its enterprise customers, a set of virtual routers that are considered as owned and managed by the customer for the purpose of connection of among different customer sites. The use of MPLS, or any other comparable technology, allows these virtual routers to efficiently create and maintain virtual links between the different virtual routers over the carrier's shared network backbone.
For many such carriers, adding multimedia services, and particularly voice services, on top of their existing IP networks, is the natural next step. Most carriers prefer to build a single shared resource to provide the multimedia services to the entire customer base, rather than building dedicated resources for each individual enterprise customer. The shared resource is often built as yet another VPN on top of the existing infrastructure, and is sometimes called a "Centralized Voice Extranet". The centralized voice extranet is implemented at a carrier centralized office (CO) where call control, call termination and other call servers, such as interactive voice response (IVR), conference, and voice mail servers, are co-located for the purpose of providing the service to enterprise customers.
In general, multimedia (and other) entities of different customers residing at different VPNs are not routable from one another, because deployment of VPNs keeps each VPN private so that its constituent devices are not exposed to other networks. Moreover, more often than not the VPNs use private IP address schemes that overlap with each other (e.g. addresses of the range 10.0.0.x or 192.168.x.x).
One way to provide centralized voice services for such enterprise customers is to employ devices that provide network address translator and firewall (NAT/FW) functions at the edge of the customer networks. This approach ensures that each enterprise is protected from the rest of the network and is uniquely addressable. However, this approach also requires expensive, and otherwise redundant, equipment to be added to each enterprise network and further complicates the routing scheme and limits the use of the virtual routers at the network itself. For the purpose of providing voice services the NAT/FW function also must support multimedia over Internet protocol (MoIP) or voice over Internet protocol (VoIP), which is known to be a significant challenge.
Therefore, in view of the limitations of the prior art, it would be advantageous to provide MoIP or VoIP services for customers that are not located on the same VPN, while not compromising the security of the VPNs.

Multimedia over internet protocol border controller for network-based virtual private networks


A microchip has a register file having a plurality of registers and an accumulator register connected in parallel with the register file that allow write operations to be performed concurrently during a single write cycle. Write operations can include write data to be written to a destination register and identification data designating a destination register. Where a first instruction designates a register in a register file and second instruction designates an accumulator register, write data from the first and second instructions can be written concurrently to the register file and the accumulator register during a single write cycle. By providing an accumulator register that is separate from the register file, data directed toward an accumulator register is diverted away from the register file and delays in performing write operations to the register file are reduced.

Pixels in an image can be represented by a pattern of bits having values indicative of luminescence levels. Image processing tasks often require the addition of bits to obtain relative intensity levels, achieve smoothing, and convert an image from one dot per inch (dpi) value to another. Generally, as the complexity of the operation increases, the number of read and write operations necessary to perform the operation also increases. For example, converting one dpi value to another dpi value involves a series of operations, such as reading bit values, combining bit values, writing bit values and incrementing register locations.
These operations often result in data being written to various registers in a single register file. As the register file typically has a single write port, such data must be written to the registers in succession. When a number of data values are waiting to be written, the probability of certain values being written after a significant period of delay increases. Delays in writing data values to register locations that exceed a number of milliseconds can lead to processing delays, system errors and system malfunction. Conventional image processing systems have attempted to solve this problem by providing two separate write ports on each register file. Although this solution is effective, the additional circuitry required to implement the additional write port increases the fabrication costs as well as the complexity of the image processing system.

Method and apparatus for performing concurrent write operations to a single-write-input register file and an accumulator register


A transmission for a twin-screw extruder with a housing (1) that accommodates a take-off shaft (5) driven by a gear and another take-off shaft (11) driven by the first take-off shaft and two distributor shafts (9) on each side. The housing is divided along a sectional joint (18) into directly connected halves (19 & 20). The housing has only one sectional joint, which is vertical and extends along the second take-off shaft. The second take-off shaft and the distributor shafts are accommodated in the sectional joint, the first take-off shaft in one housing half (20), and the driveshaft in the other housing half (19).

The present invention concerns a transmission for a twin-screw extruder.
The two screws in extruders of this genus are slightly separated and rotate in the same or in opposite senses. The transmission's take-off shafts must accordingly also be close to each other and be rotated at the same torque. The purpose of the transmission is to reduce the speed of the motor, to convert and divide the torque, and to accommodate the axial forces that accompany the extrusion.
The housing of one known transmission of this genus (European Published Application 716 914) is divided into an intake half and an outtake half by a vertical sectional joint. The intake half accommodates a gear and the intake end of the distributor shafts. This approach allows a shorter transmission and housing. To facilitate assembly, the housing is divided along and at the level of each shaft, with the intake half including two and the outtake half three horizontal plane areas. The expense of machining the housing increases, and the precision of the transmission decreases, however, with the number of sectional joints.


A system for transducer compensation based on ambient conditions includes a transducer, a signal processor and an ambient condition sensor. The signal processor may process audio signals for the transducer. In addition, the signal processor may receive signals from the ambient condition sensor. The signals may represent ambient conditions being experienced by the transducer. The signal processor may dynamically adjust the equalization of the audio signals based on the ambient conditions to optimize operation of the transducer.

1. Technical Field
The invention generally relates to transducers and, more particularly, to transducer dynamic compensation based on ambient conditions.
2. Related Art
Almost all vehicles and other audio systems include loudspeakers to provide sound based entertainment to listeners. In general, loudspeakers are transducers utilizing electrical signals to reproduce sound. In the prior art, heating resulting from the electrical signals supplied to a loudspeaker voice coil may be determined and the loudspeaker sound performance may be compensated based on the heating.
The performance of loudspeakers is also affected by ambient conditions such as temperature, humidity and barometric pressure. As the ambient conditions vary, the loudspeaker undergoes changes. These changes are most diverse at ambient condition extremes that audio systems and vehicles experience throughout many parts of the world. For example in parts of Canada and Sweden vehicles will be operated at temperatures between −40° C. and +40° C. throughout annual season changes. With sun shining on vehicles, interior cabin and trunks may reach temperatures over +80° C.
The effects of variations in ambient conditions may cause changes up to 100% or greater in some loudspeaker parameters, for example resonance frequency. These changes have implications in at least two areas, namely, quality of sound and robustness. Thus, the loudspeaker will perform differently at different ambient conditions. These variations in performance may cause a change in the quality of the reproduced sound. For example, there may be a difference in the frequency response as the ambient temperature varies.
Robustness refers to the durability of the loudspeaker. When a loudspeaker is operating at extreme ambient conditions the loudspeaker may experiences different mechanical and thermal stresses that can impact the robustness and thus life of the device. The cause of ambient condition induced changes in loudspeaker performance may be due to changes in the properties of the suspension components. Ambient condition induced performance changes may also affect the loudspeaker magnet energy level. As the magnet energy level changes with changing ambient conditions, the force applied to the moving components may be affected. Accordingly, a need exists for loudspeaker dynamic ambient condition compensation.

System for transducer compensation based on ambient conditions

Harman International Industries, Incorporated


A personal watercraft is disclosed as including an engine and a forced air induction system including an aftermarket supercharger. The aftermarket supercharger replaces the personal watercraft's original-equipment supercharger and increases the charge of compressed air provided to the engine. The preferred supercharger incorporates a spur gear that includes a smaller pitch diameter than the original-equipment supercharger. The smaller spur gear and engine flywheel thereby provide an increased gear ratio and permit greater supercharger rotational speeds when compared with the original supercharged engine. In order to permit intermeshing engagement with the engine flywheel, the spur gear is axially offset from the original spur gear axis. However, the supercharger case maintains the same engine-mating surface as the original-equipment supercharger so that the case may be received within a complemental socket of the engine housing. Other embodiments relate to aspects of the invention applicable to original equipment and other internal combustion engine applications.

1. Field of the Invention
The present invention relates generally to supercharged engines. More specifically, the present invention concerns a supercharged engine with an aftermarket supercharger that replaces the original-equipment supercharger, which is preferably designed for use in a personal watercraft.
2. Discussion of Prior Art
Supercharged engines, with forced air induction systems installed either as original equipment or as aftermarket equipment, are well known in the art. Such prior art engines commonly include limited mounting locations for the supercharger. For example, turning to FIGS. 2, 4, 4a, and 8a, a prior art supercharged engine SE is illustrated that presents a single mounting location that is also non-adjustable. The illustrated supercharged engine SE is incorporated into a SEA-DOO® personal watercraft, manufactured by Bombardier Recreational Products, Inc., Quebec, Canada. The supercharged engine SE includes an engine E and a supercharger SC. The engine E includes the mounting location that receives and supports the supercharger SC. Referring to FIGS. 4 and 4a, these figures are conceptual drawings that represent Applicants' understanding of the prior art, and it is particularly noted that the prior art construction may actually vary slightly from Applicants' understanding.
Supercharged engines and aftermarket superchargers are problematic and suffer from certain limitations. Prior art supercharged engines are not designed to take advantage of recent supercharger technology improvements, particularly those improvements introduced by the Assignee of the present application. Such improvements permit the supercharger compression element of a supercharger to safely and reliably spin at much greater rotational speeds than the superchargers installed on the prior art supercharged engines. Additionally, prior art vehicle and supercharged engine configurations include power-take-off mechanisms and present supercharger mounting configurations that typically restrict or preclude the replacement of the original-equipment supercharger with aftermarket superchargers. Furthermore, conventional techniques for installing aftermarket superchargers, e.g., chain or belt drives, are particularly deficient where the engine and supercharger are drivingly interconnected by a gear drive and the surrounding structure prevents the installation of conventional belt or chain drives. Therefore, the conventional techniques do not permit the addition of aftermarket superchargers that provide greater rotational speeds than original-equipment superchargers.

Aftermarket supercharger for personal watercraft


In a process for producing fine monofilaments having improved abrasion resistance from a polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min at a linear density of 5–20 dtex (0.027 mm–0.053 mm), a compound consisting of 80 to 99.9% by weight of chips and 20 to 0.1% by weight of an additive is added to the extruder, the melt is spun at a speed of at least 1200 m/min, the fibre is cooled in an air bath at room temperature, supplementarily stretched at a temperature of 110–150° C. to a linear density of 5–20 dtex and wound up.

1. Field of the Invention
The invention relates to a process for producing fine monofilaments having improved abrasion resistance from polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min, to a monofilament of polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min having improved abrasion resistance and a linear density of 5–20 dtex (0.027 mm–0.053 mm) and also to the use thereof.
2. Description of Related Art
Industrial fabrics composed of polypropylene are becoming of increased interest in the automotive industry, in particular because they are lighter and more stable to environmental effects and mechanical stress than other thermoplastic materials. There is a particular demand for fine monofilaments, which permit a further weight reduction. By fine monofilaments are meant monofilaments having a linear density of less than 30 dtex and especially less than 25 dtex.
However, monofilaments composed of polypropylene only have the disadvantage of severe dusting in the weaving operation as a consequence of the low abrasion resistance of pure polypropylene, although other thermoplastics are known to have an abrasion problem too. For instance, EP-A2 0 784 107 mentions melt-spun polyamide, polyester and polypropylene monofils and shows that abrasion-resistant filaments are obtained with 70–99% by weight of fibre-forming polymer and 1–30% by weight of a maleic anhydride modified polyethylene-polypropylene rubber and further additives. However, the examples are limited to nylon 6 and polyethylene terephthalate and to a copolyamide of PA66 and PA6 as fibre-forming polymer. Spinning speeds are not reported. The relatively thick monofilaments exemplified are useful for papermachine wire fabrics and lawn mower wires. The production of relatively fine polypropylene monofilaments is not disclosed.
EP-A-1059370 discloses a method for the production of polypropylene multifilaments for textile purposes. The starting material used is a metallocene-catalysed isotactic polypropylene having a melt flow index of less than 25 g per 10 minutes in order that the desired shrinkage properties may be achieved. Low-shrinkage filaments are preferably produced using polypropylene chips having a high MFI value. The yarns produced are only described in general terms. Monofilaments are not described at all.
EP-A-0028844 describes a textile multifil polypropylene filament yarn. The starting polymer is a polypropylene having a melt flow index between about 20 and 60. The problem of abrasion encountered in the processing of fine monofilaments was evidently not observed under the reported spinning and stretching conditions and in the course of the further processing.

Production of polypropylene fine monofilaments, polypropylene fine monofilaments and use thereof

Abstract: The monofilaments comprising a polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min, having improved abrasion resistance, and a linear density of 5–20 dtex (0.027 mm–0.053 mm) and an abrasion resistance score ≦2. The monofilaments have a tenacity of at least 48 cN/tex and an elongation at break of less than 45% for a mechanical constant (constante méchanique) of at least 295 cN/tex and a specific work to break value of more than 61.5 cN·cm/dtex.

Abstract: The fine monofilaments according to the invention are useful for producing woven screen fabrics for filtration and screen printing without abrasion deposits.